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Find video protocols related to scientific articles indexed in Pubmed.
Efficacy and safety of biapenem in treatment of infectious disease: a meta-analysis of randomized controlled trials.
J Chemother
PUBLISHED: 11-20-2014
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Background: Biapenem is a parenteral carbapenem antibiotic that has powerful antibacterial activity. The aim of this study is to evaluate the efficacy and safety of biapenem for the treatment of infection diseases. Methods: We performed a meta-analysis of published randomized-controlled trials (RCTs) identified in Embase, PubMed, and Cochrane library that compared the efficacy and safety of biapenem with other antibiotic regimes for the treatment of patients with infections. Results: Eight RCTs were included in the meta-analysis, involving totally 1685 patients with lower respiratory tract infections (LRTIs), complicated urinary tract infections (cUTIs), and complicated intra-abdominal infections (cIAIs). There was no difference found between the patients with LRTIs, cUTIs, or cIAIs treated with biapenem and comparators, regarding treatment success and adverse events. Conclusion: This meta-analysis provides evidence that biapenem can be used as effectively and safely as imipenem-cilstatin or meropenem, for the treatment of patients with LRTIs, cUTIs, and cIAIs. It may be a considerable option for the treatment of these infections.
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Bridging silicon nanoparticles and thermoelectrics: phenylacetylene functionalization.
Faraday Discuss.
PUBLISHED: 11-20-2014
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Silicon is a promising alternative to current thermoelectric materials (Bi2Te3). Silicon nanoparticle based materials show especially low thermal conductivities due to their high number of interfaces, which increases the observed phonon scattering. The major obstacle with these materials is maintaining high electrical conductivity. Surface functionalization with phenylacetylene shows an electrical conductivity of 18.1 S m(-1) and Seebeck coefficient of 3228.8 ?V K(-1) as well as maintaining a thermal conductivity of 0.1 W K(-1) m(-1). This gives a ZT of 0.6 at 300 K which is significant for a bulk silicon based material and is similar to that of other thermoelectric materials such as Mg2Si, PbTe and SiGe alloys.
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Development of a Clickable Designer Monolignol for Interrogation of Lignification in Plant Cell Walls.
Bioconjug. Chem.
PUBLISHED: 11-19-2014
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Lignin is an abundant and essential polymer in land plants. It is a prime factor in the recalcitrance of lignocellulosic biomass to agricultural and industrial end-uses such as forage, pulp and papermaking, and biofuels. To better understand lignification at the molecular level, we are developing a lignin spectroscopic and imaging toolbox on one "negligible" auxiliary. Toward that end, we describe the design, synthesis, and characterization of a new designer monolignol, 3-O-propargylcaffeyl alcohol, which contains a bioorthogonal alkynyl functional group at the 3-O-position. Importantly, our data indicate that this monolignol does not alter the fidelity of lignification. We demonstrate that the designer monolignol provides a platform for multiple spectroscopic and imaging approaches to reveal temporal and spatial details of lignification, knowledge of which is critical to reap the potential of energy-rich renewable plant biomass for sustainable liquid fuels and other diverse economic applications.
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Evaluation of Plasma Exchange and Continuous Veno-Venous Hemofiltration for the Treatment of Severe Avian Influenza A (H7N9): A Cohort Study.
Ther Apher Dial
PUBLISHED: 11-04-2014
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Avian influenza A (H7N9) is a severe disease with high mortality. Hypercytokinemia is thought to play an important role in the pathogenesis. This study was to investigate the efficiency of plasma exchange (PE)?+?continuous veno-venous hemofiltration (CVVH) on the removal of inflammatory mediators and their benefits in the management of fluid overload and metabolic disturbance. In total, 40 H7N9-infected patients were admitted to our hospital. Sixteen critically ill H7N9-infected patients received combination of PE and CVVH. Data from these 16 patients were collected and analyzed. The effects of PE?+?CVVH on plasma cytokine/chemokine levels and clinical outcomes were examined. H7N9-infected patients had increased plasma levels compared to healthy controls. After 3?h of PE?+?CVVH treatment, the cytokine/chemokine levels descended remarkably to lower levels and were maintained thereafter. PE?+?CVVH also benefited the management of fluid, cardiovascular dysfunction and metabolic disturbance. Of the 16 critically ill patients who received PE?+?CVVH, 10 patients survived. PE?+?CVVH decreased the plasma cytokine/chemokine levels significantly. PE?+?CVVH were also beneficial to the management of severe avian influenza A (H7N9).
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American society for parenteral and enteral nutrition and academy of nutrition and dietetics: revised 2014 standards of practice and standards of professional performance for registered dietitian nutritionists (competent, proficient, and expert) in nutrition support.
Nutr Clin Pract
PUBLISHED: 11-01-2014
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This 2014 revision of the Standards of Practice (SOP) and Standards of Professional Performance (SOPP) for Registered Dietitians Nutritionists (RDNs) in Nutrition Support represents an update of the 2007 Standards composed by content experts of the American Society for Parenteral and Enteral Nutrition and the Academy of Nutrition and Dietetics. The revision is based upon the Revised 2012 SOP in Nutrition Care and SOPP for RDs, which incorporates the Nutrition Care Process and the six domains of professionalism: Quality in Practice, Competence and Accountability, Provision of Services, Application of Research, Communication and Application of Knowledge, and Utilization and Management of Resources. These SOP and SOPP are designed to promote the provision of safe, effective, and efficient nutrition support services, facilitate evidence-based practice, and serve as a professional evaluation resource for RDNs who specialize or wish to specialize in nutrition support therapy. These standards should be applied in all patient/client care settings in which RDNs in nutrition support provide care. These settings include, but are not limited to, acute care, ambulatory/outpatient care, and home and alternate site care. The standards highlight the value of the nutrition support RDN's roles in quality management, regulatory compliance, research, teaching, consulting, and writing for peer-reviewed professional publications. The standards assist the RDN in nutrition support to distinguish his or her level of practice (competent, proficient, or expert) and would guide the RDN in creating a personal development plan to achieve increasing levels of knowledge, skill, and ability in nutrition support practice.
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Predictable and controllable dual-phase interfaces in TiO2(B)/anatase nanofibers.
Nanoscale
PUBLISHED: 10-31-2014
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The TiO2(B)/anatase dual-phase nanofiber exhibits enhanced photocatalytic activity when interfaces form during phase transformation of TiO2. To precisely control the formation of coherent interfaces between TiO2(B) and anatase, a thorough knowledge of phase transformation particularly from TiO2(B) to anatase (TA) is required. In our study, a crystallographic model in conjunction with transmission electron microscopy (TEM) was employed to investigate the phase transformation. The coherent interface with a crystallographic orientation relationship of [001]TB//[100]TA, (200)TB//(002)TA, and (020)TB//(020)TA predicted by the crystallography model was also observed by TEM experimentally. In addition, two types of incoherent interfaces that may deteriorate photocatalytic activity were examined and can be eliminated via an accurate tuning of calcination. The fundamental knowledge acquired from this work, therefore, provides a new insight to synthesize more efficient dual-phase TiO2 photocatalysts.
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PD-L1 driven Tolerance Protects Neurogenin3-induced Islet Neogenesis to Reverse Established Type 1 Diabetes in NOD Mice.
Diabetes
PUBLISHED: 10-22-2014
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A breakdown in self-tolerance underlies autoimmune destruction of ?-cells and Type 1 diabetes. A cure by restoring ?-cell mass is limited by the availability of transplantable ?-cells and the need for chronic immunosuppression. Recent evidence indicates that inhibiting co-stimulation via PD-1/PD-L1 pathway is central to immune tolerance. We, therefore, tested if induction of islet neogenesis in the liver, protected by PD-L1-driven tolerance, reverses diabetes in NOD mice. We demonstrate a robust induction of neo-islets in the liver of diabetic NOD mice by gene transfer of Ngn3, the islet-defining factor, along with betacellulin, an islet growth factor. These neo-islets express all the major pancreatic hormones and transcription factors. However, an enduring restoration of glucose-stimulated insulin secretion and euglycemia occurs only when tolerance is also induced by the targeted overexpression of PD-L1 in the neo-islets, which results in inhibition of proliferation and increased apoptosis of infiltrating CD4+T-cells. Further analysis revealed an inhibition of cytokine production from lymphocytes isolated from the liver but not from the spleen of treated mice, indicating that treatment did not result in generalized immunosuppression. This treatment strategy leads to persistence of functional neo-islets that resist autoimmune destruction and consequently an enduring reversal of diabetes in NOD mice.
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Inhibition of p70 S6 Kinase (S6K1) Activity by A77 1726 and Its Effect on Cell Proliferation and Cell Cycle Progress.
Neoplasia
PUBLISHED: 10-01-2014
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Leflunomide is a novel immunomodulatory drug prescribed for treating rheumatoid arthritis. It inhibits the activity of protein tyrosine kinases and dihydroorotate dehydrogenase, a rate-limiting enzyme in the pyrimidine nucleotide synthesis pathway. Here, we report that A77 1726, the active metabolite of leflunomide, inhibited the phosphorylation of ribosomal protein S6 and two other substrates of S6K1, insulin receptor substrate-1 and carbamoyl phosphate synthetase 2, in an A375 melanoma cell line. A77 1726 increased the phosphorylation of AKT, p70 S6 (S6K1), ERK1/2, and MEK through the feedback activation of the IGF-1 receptor-mediated signaling pathway. In vitro kinase assay revealed that leflunomide and A77 1726 inhibited S6K1 activity with IC50 values of approximately 55 and 80 ?M, respectively. Exogenous uridine partially blocked A77 1726-induced inhibition of A375 cell proliferation. S6K1 knockdown led to the inhibition of A375 cell proliferation but did not potentiate the antiproliferative effect of A77 1726. A77 1726 stimulated bromodeoxyuridine incorporation in A375 cells but arrested the cell cycle in the S phase, which was reversed by addition of exogenous uridine or by MAP kinase pathway inhibitors but not by rapamycin and LY294002 (a phosphoinositide 3-kinase inhibitor). These observations suggest that A77 1726 accelerates cell cycle entry into the S phase through MAP kinase activation and that pyrimidine nucleotide depletion halts the completion of the cell cycle. Our study identified a novel molecular target of A77 1726 and showed that the inhibition of S6K1 activity was in part responsible for its antiproliferative activity. Our study also provides a novel mechanistic insight into A77 1726-induced cell cycle arrest in the S phase.
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[Diagnosis and endoscopic treatment of isolated sphenoid sinus disease].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 09-16-2014
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This study was to investigate the clinical symptoms, characterization of imaging technique and the effect of endonasal endoscopic surgery.
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Identification of appropriate reference genes for human mesenchymal stem cell analysis by quantitative real-time PCR.
Biotechnol. Lett.
PUBLISHED: 09-02-2014
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Normalization to a reference gene is the method of choice for quantitative reverse transcription-PCR (RT-qPCR) analysis. The stability of reference genes is critical for accurate experimental results and conclusions. We have evaluated the expression stability of eight commonly used reference genes found in four different human mesenchymal stem cells (MSC). Using geNorm, NormFinder and BestKeeper algorithms, we show that beta-2-microglobulin and peptidyl-prolylisomerase A were the optimal reference genes for normalizing RT-qPCR data obtained from MSC, whereas the TATA box binding protein was not suitable due to its extensive variability in expression. Our findings emphasize the significance of validating reference genes for qPCR analyses. We offer a short list of reference genes to use for normalization and recommend some commercially-available software programs as a rapid approach to validate reference genes. We also demonstrate that the two reference genes, ?-actin and glyceraldehyde-3-phosphate dehydrogenase, are frequently used are not always successful in many cases.
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3'-Deoxy-3'-[(18)F]-fluorothymidine PET/CT in early determination of prognosis in patients with esophageal squamous cell cancer : Comparison with [(18)F]-FDG PET/CT.
Strahlenther Onkol
PUBLISHED: 08-28-2014
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The purpose of this work was to investigate the prognostic value of response analysis using early 3'-deoxy-3'-[(18)F]-fluorothymidine ((18)F-FLT) PET/CT in esophageal squamous cancer patients and make a comparison with [(18)F]-fluorodeoxyglucose ((18)F-FDG) PET/CT.
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The effects of genetic variation in FTO rs9939609 on obesity and dietary preferences in Chinese Han children and adolescents.
PLoS ONE
PUBLISHED: 08-11-2014
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The association of the rs9939609 single nucleotide polymorphism in FTO gene with obesity has been extensively investigated in studies of populations of European, African, and Asian ancestry. However, inconsistent results have been reported in Asian populations, and the relationship of FTO variation and dietary behaviors has only rarely been examined in Chinese children and adolescents. The aim of this study was to assess the association of rs9939609 with obesity and dietary preferences in childhood in a Chinese population. Epidemiological data including dietary preferences were collected in interviews using survey questionnaires, and rs9939609 genotype was determined by real-time PCR. The associations of rs9939609 genotypes with obesity and dietary preferences were analyzed by multivariate logistic regression using both additive and dominant models. The results showed that subjects with a TA or AA genotype had an increased risk of obesity compared with the TT participants; the odds ratios (ORs) were 1.47 (95% CI: 1.25-1.71, P?=?1.73×10-6), and 3.32 (95% CI: 2.01-5.47, P?=?2.68×10-6), respectively. After adjusting for age and gender, body mass index, waist circumference, hip circumference, systolic blood pressure, diastolic blood pressure, fasting blood glucose, triglycerides, and low-density lipoprotein cholesterol were higher, and high-density lipoprotein cholesterol was lower in TA and AA participants than in those with the TT genotype. After additionally controlling for body mass index, the association remained significant only for systolic blood pressure (P?=?0.005). Compared with TT participants, those with the AA genotype were more likely to prefer a meat-based diet (OR?=?2.81, 95% CI: 1.52-5.21). The combined OR for obesity in participants with TA/AA genotypes and preference for a meat-based diet was 4.04 (95% CI: 2.8-5.81) compared with the TT participants who preferred a plant-based diet. These findings indicate the genetic variation of rs9939609 is associated with obesity and dietary preferences in Chinese children and adolescents.
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The sonic hedgehog signaling pathway maintains the cancer stem cell self-renewal of anaplastic thyroid cancer by inducing snail expression.
J. Clin. Endocrinol. Metab.
PUBLISHED: 07-31-2014
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Cancer stem cells (CSCs) have been recently identified in thyroid neoplasm. Anaplastic thyroid cancer (ATC) contains a higher percentage of CSCs than well-differentiated thyroid cancer. The signaling pathways and the transcription factors that regulate thyroid CSC self-renewal remain poorly understood.
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Experimental and theoretical investigations of energy transfer and hydrogen-bond breaking in small water and HCl clusters.
Acc. Chem. Res.
PUBLISHED: 07-29-2014
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Water is one of the most pervasive molecules on earth and other planetary bodies; it is the molecule that is searched for as the presumptive precursor to extraterrestrial life. It is also the paradigm substance illustrating ubiquitous hydrogen bonding (H-bonding) in the gas phase, liquids, crystals, and amorphous solids. Moreover, H-bonding with other molecules and between different molecules is of the utmost importance in chemistry and biology. It is no wonder, then, that for nearly a century theoreticians and experimentalists have tried to understand all aspects of H-bonding and its influence on reactivity. It is somewhat surprising, therefore, that several fundamental aspects of H-bonding that are particularly important for benchmarking theoretical models have remained unexplored experimentally. For example, even the binding strength between two gas-phase water molecules has never been determined with sufficient accuracy for comparison with high-level electronic structure calculations. Likewise, the effect of cooperativity (nonadditivity) in small H-bonded networks is not known with sufficient accuracy. An even greater challenge for both theory and experiment is the description of the dissociation dynamics of H-bonded small clusters upon acquiring vibrational excitation. This is because of the long lifetimes of many clusters, which requires running classical trajectories for many nanoseconds to achieve dissociation. In this Account, we describe recent progress and ongoing research that demonstrates how the combined and complementary efforts of theory and experiment are enlisted to determine bond dissociation energies (D0) of small dimers and cyclic trimers of water and HCl with unprecedented accuracy, describe dissociation dynamics, and assess the effects of cooperativity. The experimental techniques rely on IR excitation of H-bonded X-H stretch vibrations, measuring velocity distributions of fragments in specific rovibrational states, and determining product state distributions at the pair-correlation level. The theoretical methods are based on high-level ab initio potential energy surfaces used in quantum and classical dynamical calculations. We achieve excellent agreement on D0 between theory and experiments for all of the clusters that we have compared, as well as for cooperativity in ring trimers of water and HCl. We also show that both the long-range and the repulsive parts of the potential must be involved in bond breaking. We explain why H-bonds are so resilient and hard to break, and we propose that a common motif in the breaking of cyclic trimers is the opening of the ring following transfer of one quantum of stretch excitation to form open-chain structures that are weakly bound. However, it still takes many vibrational periods to release one monomer fragment from the open-chain structures. Our success with water and HCl dimers and trimers led us to embark on a more ambitious project: studies of mixed water and HCl small clusters. These clusters eventually lead to ionization of HCl and serve as prototypes of acid dissociation in water. Measurements and calculations of such ionizations are yet to be achieved, and we are now characterizing these systems by adding monomers one at a time. We describe our completed work on the HCl-H2O dimer and mention our recent theoretical results on larger mixed clusters.
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Local-Monomer Calculations of the Intramolecular IR Spectra of the Cage and Prism Isomers of HOD(D2O)5 and HOD and D2O Ice Ih.
J Phys Chem B
PUBLISHED: 07-11-2014
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Dilute mixtures of HOD in pure H2O and D2O ices and liquid have been used by experimentalists to focus on the spectrum and vibrational dynamics of the local OH and OD stretches and bend of HOD in these complex and highly heterogeneous environments. The hexamer version of the mixture is HOD(D2O)5. The cage isomer of this cluster was recently studied and analyzed theoretically using local-mode calculations of the IR spectrum by Skinner and co-workers. This and the further possibility of experimental investigation of this cluster have stimulated us to study HOD(D2O)5 using the three-mode, local-monomer model, with the ab initio WHBB dipole moment and potential energy surfaces. Both the cage and prism isomers of this cluster are considered. In addition to providing additional insight into the HOD portion of the spectrum, the spectral signatures of each D2O are also presented in the range of 1000-4000 cm(-1). The OH stretch bands of both the prism and cage isotopomers exhibit rich structures in the range of 3100-3700 cm(-1) that are indicative of the position of the HOD in these hexamers. A preliminary investigation of the site preference of the HOD is also reported for both cage and prism HOD(D2O)5 using an harmonic zero-point energy analysis of the entire cluster. This indicates that the energies of free-OH sites are lower than the ones of H-bonded OH sites. Finally, following our earlier work on the IR spectra of H2O ice models, we present IR spectra of pure D2O and HOD.
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Novel approach to the preparation of organic energetic film for microelectromechanical systems and microactuator applications.
ACS Appl Mater Interfaces
PUBLISHED: 07-08-2014
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An activated RDX-Fe2O3 xerogel in a Si-microchannel plate (MCP) has been successfully prepared by a novel propylene epoxide-mediated sol-gel method. A decrease of nearly 40 °C in decomposition temperature has been observed compared with the original cyclotrimethylene trinitramine (RDX). The RDX-Fe2O3 xerogel can release gas and solid matter simultaneously, and the ratio of gas to solid can be tailored easily by changing the initial proportions of RDX and FeCl3·6H2O, which significantly enhances the explosive and propulsion effects and is of great benefit to the applications. The approach, which is simple, safe, and fully compatible with MEMS technology, opens a new route to the introduction of organic energetic materials to a silicon substrate.
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Construction and management of ARDS/sepsis registry with REDCap.
J Thorac Dis
PUBLISHED: 07-05-2014
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The study aimed to construct and manage an acute respiratory distress syndrome (ARDS)/sepsis registry that can be used for data warehousing and clinical research.
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[Argon plasma coagulation combined CO2 freezing through the flexible bronchoscope for treatment of airway granulation proliferation in children].
Zhonghua Er Ke Za Zhi
PUBLISHED: 06-28-2014
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To explore the safety and the efficacy of bronchoscopic argon plasma coagulation (APC) combined with CO2 freezing for the treatment of airway granulation hyperplasia after pediatric airway stenting.
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Application of sequential (18)F-FDG PET/CT scans for concurrent chemoradiotherapy of non-surgical squamous cell esophageal carcinoma.
J BUON
PUBLISHED: 06-27-2014
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To explore the values of sequential (18)F-FDG PET/CT scanning in patients with non-surgical esophageal squamous cell carcinoma (ESCC) who received concurrent chemoradiotherapy (CCRT).
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Comprehensive characterization of four different populations of human mesenchymal stem cells as regards their immune properties, proliferation and differentiation.
Int. J. Mol. Med.
PUBLISHED: 06-18-2014
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In the present study, we compared mesenchymal stem cells (MSCs) derived from 4 different sources, human bone marrow (BM), adipose tissue (AT), umbilical cord Wharton's Jelly (WJ) and the placenta (PL), in order to determine which population of MSCs displayed the most prominent immunosuppressive effects on phytohemagglutinin-induced T cell proliferation, and which one had the highest proliferative and differentiation potential. MSC and T lymphocyte co-culture (mixed culture) was used to determine whether the MSCs inhibit T cell proliferation, as well as which population of MSCs has the strongest inhibitory ability. The expression of immune-related genes was analyzed by RT-PCR and RT-qPCR. The proliferation and differentiation potential of the MSCs were determined using standard methods. Following MSC and T cell co-culture, mitogen-induced T cell proliferation was effectively suppressed by all 4 populations of MSCs. This occurred through soluble factors rather than direct contact inhibition. Among the 4 populations of MSCs, the WJ-MSC has the strongest suppression effects. On immune related genes, WJ-MSC has the weakest expression of MHC II genes, TLR4, TLR3, JAG1, NOTCH2 and NOTCH3. To compare the proliferation potential, WJ-MSCs showed the most rapid growth rate followed by the AT-, PL- and BM-MSCs. As regards differentiation potential, the WJ-MSCs had the strongest osteogenetic ability followed by PL, AT and BM-MSC. AT-MSC has the strongest adipogenetic ability followed by the WJ-, BM- and PL-MSCs. These data indicated that the WJ-MSCs had the strongest immunomodulatory and immunosuppressive potential. In light of these observations, we suggest that WJ-MSCs are the most attractive cell population for use in immune cellular therapy when immunosuppressive action is required.
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Tunicamycin-induced ER stress regulates chemokine CCL5 expression and secretion via STAT3 followed by decreased transmigration of MCF-7 breast cancer cells.
Oncol. Rep.
PUBLISHED: 06-11-2014
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Chemokine C-C motif ligand 5 (CCL5) is an important marker related to the progression of breast cancer and is upregulated in cancer cells. However, the mechanism of the overexpression of CCL5 in tumours has not yet been clarified. The present study aimed to investigate the role of endoplasmic reticulum (ER) stress in regulating CCL5 expression and its relationship with signal transducer and activator of transcription 3 (STAT3). Meanwhile, the effect of tunicamycin, a classical ER stress inducer, and CCL5 on the transmigration of human breast cancer MCF-7 cells was observed and analysed. Compared with the normal breast epithelial tissues, expression levels of CCL5, STAT3 and CHOP, an indicator of ER stress, were significantly upregulated in breast cancer tissues. In human breast cancer MCF-7 cells, ER stress activator tunicamycin increased the expression of CCL5, STAT3 and CHOP in a time- and concentration-dependent manner. Moreover, tunicamycin-induced CCL5 expression was positively related to upregulation of unphosphorylated STAT3 (U-STAT3) but negatively related to STAT3 phosphorylation at the Tyr705 site. Furthermore, ER stress inhibited CCL5 secretion and transmigration of MCF-7 cells. This study also showed that extracellular rhCCL5 induced transmigration of MCF-7 cells which was partially blocked by the CCR5 monoclonal antibody, while knockdown of endogenous expression of CCL5 did not affect the transmigration of the cells. In conclusion, ER stress induced endogenous expression of CCL5 via elevating U-STAT3 expression; however, ER stress inhibited CCL5 secretion, which in turn, decreased the transmigration of breast cancer MCF-7 cells.
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Brownian motion of tethered nanowires.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 05-13-2014
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Brownian motion of slender particles near a boundary is ubiquitous in biological systems and in nanomaterial assembly, but the complex hydrodynamic interaction in those systems is still poorly understood. Here, we report experimental and computational studies of the Brownian motion of silicon nanowires tethered on a substrate. An optical interference method enabled direct observation of microscopic rotations of the slender bodies in three dimensions with high angular and temporal resolutions. This quantitative observation revealed anisotropic and angle-dependent hydrodynamic wall effects: rotational diffusivity in inclined and azimuth directions follows different power laws as a function of the length, ?L^{-2.5} and ?L^{-3}, respectively, and is more hindered for smaller inclined angles. In parallel, we developed an implicit simulation technique that takes the complex wire-wall hydrodynamic interactions into account efficiently, the result of which agreed well with the experimentally observed angle-dependent diffusion. The demonstrated techniques provide a platform for studying the microrheology of soft condensed matters, such as colloidal and biological systems near interfaces, and exploring the optimal self-assembly conditions of nanostructures.
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Reversibility and stability of ZnO-Sb?Te? nanocomposite films for phase change memory applications.
ACS Appl Mater Interfaces
PUBLISHED: 05-08-2014
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(ZnO)x(Sb2Te3)1-x materials with different ZnO contents have been systemically studied with an aim of finding the most suitable composition for phase change memory applications. It was found that ZnO-doping could improve thermal stability and electrical behavior of Sb2Te3 film. Sb2Te3-rich nanocrystals, surrounded by ZnO-rich amorphous phases, were observed in annealed ZnO-doped Sb2Te3 composite films, and the segregated domains exhibited a relatively uniform distribution. The ZnO-doped Sb2Te3 composite films, especially with 5.2 at% ZnO concentration were found to have higher crystallization temperature, higher crystalline resistance, and faster crystallization speed in comparison with Ge2Sb2Te5. A reversible repetitive optical switching behavior can be observed in (ZnO)5.2(Sb2Te3)94.8, confirming that the ZnO doping is responsible for a fast switching and the compound is stable with cycling. Therefore, it is promising for the applications in phase change memory devices.
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A comparison of biochars from lignin, cellulose and wood as the sorbent to an aromatic pollutant.
J. Hazard. Mater.
PUBLISHED: 04-29-2014
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Biochars' performance as the sorbent to pollutants is dependent on their compositions and surface characteristics, which are then related to the feedstock used for biochar preparation. The objective of this work is to probe the feedstock's influence on biochar's sorption property through a comparative study on biochars from lignin, cellulose and wood prepared at 400°C and 600°C, respectively. Elemental and spectral analyses demonstrated that the wood biochar had a composition and carbonization degree close to the cellulose biochar but much different from the lignin biochar prepared at the same temperature, suggesting that lignin is not dominant to properties of plant-derived biochars. The lignin biochar showed a sorption capacity comparable to both cellulose and wood biochars as the sorbent to nitrobenzene, with a higher partition contribution to the total sorption due to the lower carbonization of lignin. In general, the lignin biochar is a good candidate of sorbent to aromatic pollutants, and is advantageous over the other two species with its efficient carbon utilization.
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Atomic mechanism of predictable phase transition in dual-phase H2 Ti3 O7 /TiO2 (B) nanofiber: an in situ heating TEM investigation.
Chemistry
PUBLISHED: 04-27-2014
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The phase transition from H(2)Ti(3)O(7) to TiO(2) (B) in a 1D single nanocrystal of H(2)Ti(3)O(7) was observed by in situ heating in a transmission electron microscope experimentally. The results indicate a typical monoclinic-to-monoclinic crystallographic orientation relationship between the two phases. Moreover, the fundamental building blocks and invariant deformation element model were both adopted to reveal the atomic mechanism and predict the crystallographic orientation relationship quantitatively for the phase transition. The prediction was precisely consistent with TEM results.
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Progress of anti-vascular endothelial growth factor therapy for ocular neovascular disease: benefits and challenges.
Chin. Med. J.
PUBLISHED: 04-26-2014
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This review aims to summarize the progress of current clinical studies in ocular angiogenesis treated with anti-vascular endothelial growth factor (VEGF) therapy and to discuss the benefits and challenges of the treatment.
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Enhanced removal of uranium(VI) by nanoscale zerovalent iron supported on Na-bentonite and an investigation of mechanism.
J Phys Chem A
PUBLISHED: 04-14-2014
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The reductive removal of U(VI) by nanoscale zerovalent iron (NZVI) was enhanced by using Na(+)-saturated bentonite (Na-bent) as the support, and the mechanism for the enhanced removal were investigated comprehensively. Under the same experimental conditions, NZVI supported on the negatively charged Na-bent showed much higher removal efficiency (99.2%) of cationic U(VI) than either bare NZVI (48.3%) or NZVI supported on the positively charged bentonite (Al-bent) did. Subsequent experimental investigations revealed the unique roles of bentonite on enhancing the reactivity and reusability of NZVI. First, Na-bent can buffer the pH in reaction media, besides preventing NZVI from aggregation. Second, Na-bent promoted the mass transfer of U(VI) from solution to NZVI surface, leading to the enhanced removal efficiency. Third, the bentonite may transfer some insoluble reduction products away from the iron surface according to X-ray absorption fine structure (XAFS) study. Finally, Na-bent as the adsorbent to Fe(II) makes it more reactive with U(VI), which enhanced stoichiometrically the reduction capacity of NZVI besides accelerating the reaction rate.
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Ab initio deconstruction of the vibrational relaxation pathways of dilute HOD in ice Ih.
J. Am. Chem. Soc.
PUBLISHED: 04-11-2014
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Coupled intramolecular and intermolecular vibrational quantum dynamics, using an ab initio potential energy surface, successfully describes the subpicosecond relaxation of the OD and OH stretch fundamental and first overtone of dilute HOD in ice Ih. The calculations indicate that more than one intermolecular mode along with the three intramolecular modes is needed to describe the relaxation, in contrast to a recent study using a phenomenological potential in just two degrees of freedom. Detailed time-dependent relaxation pathways from 6-mode calculations are also given.
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Intragenic and extragenic disruptions of FOXL2 mapped by whole genome low-coverage sequencing in two BPES families with chromosome reciprocal translocation.
Genomics
PUBLISHED: 04-09-2014
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Blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) is a rare autosomal dominant disorder that affects craniofacial development and ovarian function. FOXL2 is the only gene known to be responsible for BPES. The majority of BPES patients show intragenic mutations of FOXL2. Recently, a 7.4 kb sequence disruption, which was 283 kb upstream of FOXL2, was identified to independently contribute to the BPES phenotype. Several breakpoints nearing FOXL2 (0 Mb to 1.2 Mb, several of which were distant from the 7.4 kb sequence disruption) have been mapped or deduced through a traditional method in BPES patients with chromosome reciprocal translocation. In this study, two BPES families with chromosome reciprocal translocation were investigated. Intragenic mutations of FOXL2 or pathogenic copy number variations were excluded for the two BPES families. All of the four breakpoints were identified at a base-precise manner using Giemsa banding and whole genome low-coverage sequencing (WGLCS). In family 01, the breakpoints were found at chr1:95,609,998 and chr3:138,879, 114 (213,132 bp upstream of FOXL2). In family 02, the breakpoints were located at chr3:138,665,431 (intragenic disruptions of FOXL2) and chr20:56,924,609. Results indicate that the intragenic and extragenic interruptions of FOXL2 can be accurately and rapidly detected using WGLCS. In addition, both the 213 kb upstream and intragenic interruptions of FOXL2 can cause BPES phenotype.
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Explosives detection in a lasing plasmon nanocavity.
Nat Nanotechnol
PUBLISHED: 04-06-2014
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Perhaps the most successful application of plasmonics to date has been in sensing, where the interaction of a nanoscale localized field with analytes leads to high-sensitivity detection in real time and in a label-free fashion. However, all previous designs have been based on passively excited surface plasmons, in which sensitivity is intrinsically limited by the low quality factors induced by metal losses. It has recently been proposed theoretically that surface plasmon sensors with active excitation (gain-enhanced) can achieve much higher sensitivities due to the amplification of the surface plasmons. Here, we experimentally demonstrate an active plasmon sensor that is free of metal losses and operating deep below the diffraction limit for visible light. Loss compensation leads to an intense and sharp lasing emission that is ultrasensitive to adsorbed molecules. We validated the efficacy of our sensor to detect explosives in air under normal conditions and have achieved a sub-part-per-billion detection limit, the lowest reported to date for plasmonic sensors with 2,4-dinitrotoluene and ammonium nitrate. The selectivity between 2,4-dinitrotoluene, ammonium nitrate and nitrobenzene is on a par with other state-of-the-art explosives detectors. Our results show that monitoring the change of the lasing intensity is a superior method than monitoring the wavelength shift, as is widely used in passive surface plasmon sensors. We therefore envisage that nanoscopic sensors that make use of plasmonic lasing could become an important tool in security screening and biomolecular diagnostics.
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Inhibition of hepatitis C virus infection by NS5A-specific aptamer.
Antiviral Res.
PUBLISHED: 03-27-2014
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To increase efficacy of hepatitis C treatment, future regiments will incorporate multiple direct-acting antiviral drugs. HCV NS5A protein was expressed and purified. Aptamers against NS5A were screened and obtained by the selective evolution of ligands by exponential enrichment approach and the antiviral actions of the aptamers were tested. The mechanisms through which the aptamers exert their antiviral activity were explored. The aptamers NS5A-4 and NS5A-5 inhibit HCV RNA replication and infectious virus production without causing cytotoxicity in human hepatocytes. The aptamers do not affect hepatitis B virus replication in HepG2.2.15 cells. Interferon beta (IFN-?) and interferon-stimulated genes (ISGs) are not induced by the aptamers in HCV-infected hepatocytes. Further study shows that domain I and domain III of NS5A protein are involved in the suppression of HCV RNA replication and infectious virus production by NS5A-4. Y2105H within NS5A is the major resistance mutation identified. NS5A aptamer disrupts the interaction of NS5A with core protein. The data suggest that the aptamers against NS5A protein may exert antiviral effects through inhibiting viral RNA replication, preventing the interaction of NS5A with core protein. Aptamers for NS5A may be used to understand the mechanisms of virus replication and assembly and served as potential therapeutic agents for hepatitis C.
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Abundance and diversity of ammonia-oxidizing microorganisms in the sediments of jinshan lake.
Curr. Microbiol.
PUBLISHED: 03-25-2014
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Community structures of ammonia-oxidizing microorganisms were investigated using PCR primers designed to specifically target the ammonia monooxygenase ?-subunit (amoA) gene in the sediment of Jinshan Lake. Relationships between the abundance and diversity of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), and physicochemical parameters were also explored. The AOA abundance decreased sharply from west to east; however, the AOB abundance changed slightly with AOB outnumbering AOA in two of the four sediment samples (JS), JS3 and JS4. The AOA abundance was significantly correlated with the NH4-N, NO3-N, and TP. No significant correlations were observed between the AOB abundance and environmental variables. AOB had a higher diversity and richness of amoA genes than AOA. Among the 76 archaeal amoA sequences retrieved, 57.89, 38.16, and 3.95 % fell within the Nitrosopumilus, Nitrososphaera, and Nitrososphaera sister clusters, respectively. The 130 bacterial amoA gene sequences obtained in this study were grouped with known AOB sequences in the Nitrosomonas and Nitrosospira genera, which occupied 72.31 % and 27.69 % of the AOB group, respectively. Compared to the other three sample sites, the AOA and AOB community compositions at JS4 showed a large difference. This work could enhance our understanding of the roles of ammonia-oxidizing microorganisms in freshwater lake environment.
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Combined electrocardiography, coronary angiography and magnetic resonance imaging for the diagnosis of viral myocarditis: A case report.
Exp Ther Med
PUBLISHED: 03-14-2014
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Endomyocardial biopsy is the gold standard for diagnosing viral myocarditis. However, this method is rarely used as it is more invasive, less sensitive and has a higher incidence of complications than other methods. With recent developments in myocarditis research, cardiovascular nuclear magnetic resonance imaging has been demonstrated to have a marked advantage over endomyocardial biopsy, specifically regarding the differential diagnosis of acute coronary syndrome, as it is noninvasive, repeatable, highly sensitive and highly specific for diagnosing myocarditis. Myocardial edema is characteristic of myocardial inflammation, myocardial necrosis and myocardial fibrosis. T2-weighted nuclear magnetic resonance imaging sensitively detects myocardial tissue edema and additional imaging parameters contribute to the diagnosis of myocarditis. Therefore, combining these methods with the current sophisticated electrocardiogram and coronary angiography examination methods may facilitate the rapid and accurate assessment of viral myocarditis. A 44-year-old male patient with symptoms of dyspnea and shortness of breath accompanied by dizziness, through electrocardiography, coronary angiography and magnetic resonance imaging, was diagnosed viral myocarditis.
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Complete replication of hepatitis B virus and hepatitis C virus in a newly developed hepatoma cell line.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 03-10-2014
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The absence of a robust cell culture system for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection has limited the analysis of the virus lifecycle and drug discovery. We have established a hepatoma cell line, HLCZ01, the first cell line, to the authors' knowledge, supporting the entire lifecycle of both HBV and HCV. HBV surface antigen (HBsAg)-positive particles can be observed in the supernatant and the lumen of the endoplasmic reticulum of the cells via electron microscopy. Interestingly, HBV and HCV clinical isolates propagate in HLCZ01 cells. Both viruses replicate in the cells without evidence of overt interference. HBV and HCV entry are blocked by antibodies against HBsAg and human CD81, respectively, and the replication of HBV and HCV is inhibited by antivirals. HLCZ01 cells mount an innate immune response to virus infection. The cell line provides a powerful tool for exploring the mechanisms of virus entry and replication and the interaction between host and virus, facilitating the development of novel antiviral agents and vaccines.
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Effect of ultimate pH on postmortem myofibrillar protein degradation and meat quality characteristics of Chinese Yellow crossbreed cattle.
ScientificWorldJournal
PUBLISHED: 03-06-2014
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This paper describes the complex effects of postmortem ultimate pH (pHu) on Chinese Yellow crossbreed cattle quality during postmortem ageing and provides an explanation of how pHu affects beef tenderness. High pHu beef had the highest initial tenderness (P < 0.05) compared with other groups at 1 day postmortem. Intermediate and low pHu beef had similar initial WBSF at 1 day postmortem, but intermediate pHu beef had slower tenderization rate than low pHu beef (P < 0.05). Purge loss, cooking loss, L*, a*, and b* values decreased with increasing pHu during ageing (P < 0.05). Myofibril fragmentation index (MFI) was higher in high pHu beef than intermediate and low pHu beef throughout ageing (P < 0.05). Protein degradation studies found that desmin and troponin-T appeared degraded within 0.5?h postmortem for high and low pHu beef, compared to >2 days for intermediate pHu beef. Overall, Chinese Yellow crossbred cattle tenderness is related to pHu, which may be affected by proteolytic enzymatic activity. Therefore, pHu may be used to predict beef tenderness and other quality characteristics during postmortem ageing. To achieve consistent tenderness, different ageing times should be used, depending on pHu.
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Proteomic analysis of lung tissue in a rat acute lung injury model: identification of PRDX1 as a promoter of inflammation.
Mediators Inflamm.
PUBLISHED: 02-20-2014
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Acute respiratory distress syndrome (ARDS) remains a high morbidity and mortality disease entity in critically ill patients, despite decades of numerous investigations into its pathogenesis. To obtain global protein expression changes in acute lung injury (ALI) lung tissues, we employed a high-throughput proteomics method to identify key components which may be involved in the pathogenesis of ALI. In the present study, we analyzed lung tissue proteomes of Pseudomonas aeruginosa-induced ALI rats and identified eighteen proteins whose expression levels changed more than twofold as compared to normal controls. In particular, we found that PRDX1 expression in culture medium was elevated by a lipopolysaccharide (LPS) challenge in airway epithelial cells in vitro. Furthermore, overexpression of PRDX1 increased the expression of proinflammatory cytokines interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-? (TNF-?), whereas knockdown of PRDX1 led to downregulated expression of cytokines induced by LPS. In conclusion, our findings provide a global alteration in the proteome of lung tissues in the ALI rat model and indicate that PRDX1 may play a critical role in the pathogenesis of ARDS by promoting inflammation and represent a novel strategy for the development of new therapies against ALI.
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Assisted reproductive technologies impair the expression and methylation of insulin-induced gene 1 and sterol regulatory element-binding factor 1 in the fetus and placenta.
Fertil. Steril.
PUBLISHED: 01-30-2014
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To evaluate the cholesterol metabolism linked to assisted reproductive technology (ART) by analyzing the expression levels and DNA methylation patterns of the insulin-induced gene (INSIG), sterol regulatory element-binding protein (SREBP), and SREBP cleavage-activating protein in the fetus and placenta.
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Potential mechanisms of carbon monoxide and high oxygen packaging in maintaining color stability of different bovine muscles.
Meat Sci.
PUBLISHED: 01-27-2014
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The objectives were to compare the effects of packaging methods on color stability, metmyoglobin-reducing-activity (MRA), total-reducing-activity and NADH concentration of different bovine muscles and to explore potential mechanisms in the enhanced color stability by carbon monoxide modified atmosphere packaging (CO-MAP, 0.4% CO/30% CO2/69.6% N2). Steaks from longissimus lumborum (LL), psoas major (PM) and longissimus thoracis (LT) packaged in CO-MAP, high-oxygen modified atmosphere packaging (HiOx-MAP, 80% O2/20% CO2) or vacuum packaging were stored for 0day, 4days, 9days, and 14days or stored for 9days then displayed in air for 0day, 1day, or 3days. The CO-MAP significantly increased red color stability of all muscles, and especially for PM. The PM and LT were more red than LL in CO-MAP, whereas PM had lowest redness in HiOx-MAP. The content of MetMb in CO-MAP was lower than in HiOx-MAP. Steaks in CO-MAP maintained a higher MRA compared with those in HiOx-MAP during storage. After opening packages, the red color of steaks in CO-MAP deteriorated more slowly compared with that of steaks in HiOx-MAP.
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Clinical significance of the stem cell gene Oct-4 in cervical cancer.
Tumour Biol.
PUBLISHED: 01-26-2014
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This study aims to investigate the association between the expression of Oct-4 and the biological behavior or prognosis of cervical cancer. Serum-free suspension culture technology was used to select a suspension of microspheres that can stabilize clones. The tumorigenicity of the microsphere suspension was analyzed in NOD/SCID mice. Microarray analysis was used to detect the specific expression of genes in the microsphere suspension. The expression of Oct-4 was detected by immunohistochemistry, and the correlation between Oct-4 expression and clinical pathological prognostic indicators was analyzed in cervical cancer. The expression of the following genes was significantly different between the experimental and control groups: stem cell differentiation (CD44 and Oct-4), markers cell cycle regulators (APC), cell cycle regulators (MYC), and self-renewal markers (MYST2, NEUROG2, and SOX1). The expression of Oct-4 was significantly higher in cervical cancer tissues than in adjacent normal tissues and was significantly related to differentiation, clinical stage, and lymph node metastasis. The 5-year survival rate of patients with Oct-4-positive expression was lower than that of patients with Oct-4-negative expression (36.7 vs. 67.7 %, respectively; P=0.001). Cox regression analysis revealed that clinical stage, lymph node metastasis, and Oct-4 were independent prognostic factors in cervical cancer (P=0.031, 0.012, and 0.001, respectively). Our results showed that Oct-4 was highly expressed in cervical cancer stem cells; Oct-4 expression was associated with biological behavior and was an independent prognostic factor in cervical cancer. Therefore, it may represent a potential target for cervical cancer treatment.
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Identification of optimal reference genes for quantitative PCR studies on human mesenchymal stem cells.
Mol Med Rep
PUBLISHED: 01-17-2014
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Quantitative polymerase chain reaction (qPCR) analysis is a commonly used method for the study of mRNA expression throughout the field of mesenchymal stem cell (MSC) research. This technology is simple and sensitive; however the results may vary significantly due to the use of various reference genes (RGs) as normalizers. Therefore, the reliable use of RGs is vital for obtaining accurate results. The present study focuses on ten putative RGs for the normalization of qPCR data between human bone marrow-derived MSCs (BM-MSCs) and fetal tissue-derived MSCs (FT-MSCs). The total RNA from these two types of MSC was isolated using TRIzol reagent. cDNA was generated from the RNA via reverse transcription and subsequently analyzed by qPCR using ten common RGs as normalizers. These RGs included 18S, ACTB, B2M, HPRT1, GAPDH, TBP, PPIA, RPLP0, PGK1 and RPL13A. GeNorm, NormFinder and BestKeeper software were used to analyze the qPCR results by evaluating the expression stabilities of the ten candidate RGs in BM-MSCs and FT-MSCs. Consequently, several of the commonly used RGs, including 18S, ACTB and TBP, were demonstrated to be unsuitable for normalization in these two MSCs, whereas RPL13A, B2M and PPIA were the most stable RGs and were therefore reliable for use in qPCR studies. Combining multiple RGs had no contribution towards increasing their stabilities. In conclusion, the present study revealed that RPL13A, B2M and PPIA were the optimal RGs for qPCR studies comparing BM-MSCs and FT-MSCs.
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Identification of stem-like cells in non-small cell lung cancer cells with specific peptides.
Cancer Lett.
PUBLISHED: 01-03-2014
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Recent studies indicate that tumor maintenance, metastasis and drug-resistance are mainly conducted by a small subset of cancer cells which are termed cancer stem cells (CSCs) or cancer stem-like cells (CSLCs). Successful identification of CSCs/CSLCs might lead to discovery of the novel and effective therapeutic targets for cancers. In our study, lung CSCs/CSLCs were enriched by sphere-forming assay. Screening and selection of specific binding peptides for lung CSCs/CSLCs were performed with bacterial surface display method. Selected peptide named HCBP-1 exhibited highest specific binding capability as examined by flow cytometry and fluorescence microscopy. Drug-resistant lung CSCs/CSLCs might be characterized with HCBP-1 peptide and several microRNAs related to the stem-like properties were discriminatively expressed in HCBP-1+ subpopulation. Moreover, at least two distinct subpopulations in H460 tumor sphere cells could be distinguished by HCBP-1 peptide. Thus, a new method was established to identify lung CSCs/CSLCs, which provided robust approaches for the research of CSCs/CSLCs.
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Spatial and temporal variations of crop fertilization and soil fertility in the loess plateau in china from the 1970s to the 2000s.
PLoS ONE
PUBLISHED: 01-01-2014
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Increased fertilizer input in agricultural systems during the last few decades has resulted in large yield increases, but also in environmental problems. We used data from published papers and a soil testing and fertilization project in Shaanxi province during the years 2005 to 2009 to analyze chemical fertilizer inputs and yields of wheat (Triticum aestivum L.) and maize (Zea mays L.) on the farmers' level, and soil fertility change from the 1970s to the 2000s in the Loess Plateau in China. The results showed that in different regions of the province, chemical fertilizer NPK inputs and yields of wheat and maize increased. With regard to soil nutrient balance, N and P gradually changed from deficit to surplus levels, while K deficiency became more severe. In addition, soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium increased during the same period. The PFP of N, NP and NPK on wheat and maize all decreased from the 1970s to the 2000s as a whole. With the increase in N fertilizer inputs, both soil total nitrogen and alkali-hydrolysis nitrogen increased; P fertilizer increased soil available phosphorus and K fertilizer increased soil available potassium. At the same time, soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium all had positive impacts on crop yields. In order to promote food safety and environmental protection, fertilizer requirements should be assessed at the farmers' level. In many cases, farmers should be encouraged to reduce nitrogen and phosphate fertilizer inputs significantly, but increase potassium fertilizer and organic manure on cereal crops as a whole.
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Fibroblast Growth Factor 21 Improves Insulin Sensitivity and Synergizes with Insulin in Human Adipose Stem Cell-Derived (hASC) Adipocytes.
PLoS ONE
PUBLISHED: 01-01-2014
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Fibroblast growth factor 21 (FGF21) has evolved as a major metabolic regulator, the pharmacological administration of which causes weight loss, insulin sensitivity and glucose control in rodents and humans. To understand the molecular mechanisms by which FGF21 exerts its metabolic effects, we developed a human in vitro model of adipocytes to examine crosstalk between FGF21 and insulin signaling. Human adipose stem cell-derived (hASC) adipocytes were acutely treated with FGF21 alone, insulin alone, or in combination. Insulin signaling under these conditions was assessed by measuring tyrosine phosphorylation of insulin receptor (InsR), insulin receptor substrate-1 (IRS-1), and serine 473 phosphorylation of Akt, followed by a functional assay using 14C-2-deoxyglucose [14C]-2DG to measure glucose uptake in these cells. FGF21 alone caused a modest increase of glucose uptake, but treatment with FGF21 in combination with insulin had a synergistic effect on glucose uptake in these cells. The presence of FGF21 also effectively lowered the insulin concentration required to achieve the same level of glucose uptake compared to the absence of FGF21 by 10-fold. This acute effect of FGF21 on insulin signaling was not due to IR, IGF-1R, or IRS-1 activation. Moreover, we observed a substantial increase in basal S473-Akt phosphorylation by FGF21 alone, in contrast to the minimal shift in basal glucose uptake. Taken together, our data demonstrate that acute co-treatment of hASC-adipocytes with FGF21 and insulin can result in a synergistic improvement in glucose uptake. These effects were shown to occur at or downstream of Akt, or separate from the canonical insulin signaling pathway.
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Rs7206790 and rs11644943 in FTO gene are associated with risk of obesity in Chinese school-age population.
PLoS ONE
PUBLISHED: 01-01-2014
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To evaluate the associations between candidate FTO single nucleotide polymorphisms (SNPs) and obesity, a case-control study was conducted among Chinese school-age children, which included 500 obese cases and 500 matched controls (age, gender and location). We selected 24 candidate FTO tag-SNPs via bio-informatics analysis and performed genotyping using SNPScan technology. Results indicated that rs7206790 and rs11644943 were significantly associated with obesity among school-age children in both additive and recessive models (P<0.05) after adjusting confounders. Comparing rs7206790 CC and CG genotype of carriers, those carrying the GG genotype had an increased risk of obesity (adjusted odds ratio [OR], 3.76; 95% Confidence interval [CI], 1.24-11.43). Carriers of the AA allele of rs11644943 had a lower risk of obesity (adjusted OR, 0.16; 95% CI, 0.04-0.72) compared with those of the T allele (TT and TA). These two SNPs (rs7206790 and rs11644943) were not Linkage Disequilibrium (LD) with previous reported obesity-associated SNPs. Under the recessive model adjusted for age and gender and location, rs7206790 GG allele carriers had significantly increased BMIs (P?=?0.012), weight (P?=?0.012), waist circumferences (WC) (P?=?0.045) and hip circumferences (HC) (P?=?0.033). Conversely, rs11644943 AA allele carriers had significantly decreased BMIs (P?=?0.006), WC (P?=?0.037) and Waist-to-height ratios (WHtR) (P?=?0.012). A dose-response relationship was found between the number of risk alleles in rs7206790, rs11644943 and rs9939609 and the risk of obesity. The Genetic Risk Score (GRS) of the reference group was 3; in comparison, those of 2, 4, and ?5 had ORs for obesity of 0.24 (95%CI, 0.05-1.13), 1.49 (95%CI, 1.10-2.01), and 5.20 (95%CI, 1.75-15.44), respectively. This study confirmed the role of FTO variation on genetic susceptibility to obesity. We reported two new obesity-related FTO SNPs (rs7206790 and rs11644943) among Chinese school-age children.
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The hepatoselective glucokinase activator PF-04991532 ameliorates hyperglycemia without causing hepatic steatosis in diabetic rats.
PLoS ONE
PUBLISHED: 01-01-2014
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Hyperglycemia resulting from type 2 diabetes mellitus (T2DM) is the main cause of diabetic complications such as retinopathy and neuropathy. A reduction in hyperglycemia has been shown to prevent these associated complications supporting the importance of glucose control. Glucokinase converts glucose to glucose-6-phosphate and determines glucose flux into the ?-cells and hepatocytes. Since activation of glucokinase in ?-cells is associated with increased risk of hypoglycemia, we hypothesized that selectively activating hepatic glucokinase would reduce fasting and postprandial glucose with minimal risk of hypoglycemia. Previous studies have shown that hepatic glucokinase overexpression is able to restore glucose homeostasis in diabetic models; however, these overexpression experiments have also revealed that excessive increases in hepatic glucokinase activity may also cause hepatosteatosis. Herein we sought to evaluate whether liver specific pharmacological activation of hepatic glucokinase is an effective strategy to reduce hyperglycemia without causing adverse hepatic lipids changes. To test this hypothesis, we evaluated a hepatoselective glucokinase activator, PF-04991532, in Goto-Kakizaki rats. In these studies, PF-04991532 reduced plasma glucose concentrations independent of changes in insulin concentrations in a dose-dependent manner both acutely and after 28 days of sub-chronic treatment. During a hyperglycemic clamp in Goto-Kakizaki rats, the glucose infusion rate was increased approximately 5-fold with PF-04991532. This increase in glucose infusion can be partially attributed to the 60% reduction in endogenous glucose production. While PF-04991532 induced dose-dependent increases in plasma triglyceride concentrations it had no effect on hepatic triglyceride concentrations in Goto-Kakizaki rats. Interestingly, PF-04991532 decreased intracellular AMP concentrations and increased hepatic futile cycling. These data suggest that hepatoselective glucokinase activation may offer glycemic control without inducing hepatic steatosis supporting the evaluation of tissue specific activators in clinical trials.
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Inhibition of hepatitis C virus infection by DNA aptamer against NS2 protein.
PLoS ONE
PUBLISHED: 01-01-2014
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NS2 protein is essential for hepatitis C virus (HCV) replication. NS2 protein was expressed and purified. Aptamers against NS2 protein were raised and antiviral effects of the aptamers were examined. The molecular mechanism through which the aptamers exert their anti-HCV activity was investigated. The data showed that aptamer NS2-3 inhibited HCV RNA replication in replicon cell line and infectious HCV cell culture system. NS2-3 and another aptamer NS2-2 were demonstrated to inhibit infectious virus production without cytotoxicity in vitro. They did not affect hepatitis B virus replication. Interferon beta (IFN-?) and interferon-stimulated genes (ISGs) were not induced by the aptamers in HCV-infected hepatocytes. Furthermore, our study showed that N-terminal region of NS2 protein is involved in the inhibition of HCV infection by NS2-2. I861T within NS2 is the major resistance mutation identified. Aptamer NS2-2 disrupts the interaction of NS2 with NS5A protein. The data suggest that NS2-2 aptamer against NS2 protein exerts its antiviral effects through binding to the N-terminal of NS2 and disrupting the interaction of NS2 with NS5A protein. NS2-specific aptamer is the first NS2 inhibitor and can be used to understand the mechanisms of virus replication and assembly. It may be served as attractive candidates for inclusion in the future HCV direct-acting antiviral combination therapies.
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Inhibition of Hepatitis C Virus Production by Aptamer for Core Protein.
J. Virol.
PUBLISHED: 12-04-2013
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Hepatitis C virus (HCV) core protein is essential for virus assembly. HCV core protein was expressed and purified. Aptamers against core protein were raised through the selective evolution of ligands by exponential enrichment approach. Detection of HCV infection by core aptamers and the antiviral activities of aptamers were characterized. The mechanism of their anti-HCV activity was determined. The data showed that selected aptamers against core specifically recognize the recombinant core protein, but also can detect serum samples from hepatitis C patients. Aptamers do not have effect on HCV RNA replication in infectious cell culture system. However, the aptamers inhibit the production of infectious virus particles. Interferon beta (IFN-?) and ISGs are not induced in viral infected hepatocytes by aptamers. Domain I and II of core protein are involved in the inhibition of infectious virus production by the aptamers. V31A within core is the major resistance mutation identified. Further study shows that the aptamers disrupt the localization of core with lipid droplets and NS5A, and perturb the association of core protein with viral RNA. The data suggest that aptamers against HCV core protein inhibit infectious virus production through disrupting the localization of core with lipid droplets and NS5A and preventing the association of core protein with viral RNA. The aptamers for core protein may be used to understand the mechanisms of virus assembly. Core-specific aptamers may hold promise for the development as early diagnostic reagents and potential therapeutic agents for chronic hepatitis C.
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Mode-specific tunneling using the Qim path: theory and an application to full-dimensional malonaldehyde.
J Chem Phys
PUBLISHED: 10-29-2013
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We present a theory of mode-specific tunneling that makes use of the general tunneling path along the imaginary-frequency normal mode of the saddle point, Qim, and the associated relaxed potential, V(Qim) [Y. Wang and J. M. Bowman, J. Chem. Phys. 129, 121103 (2008)]. The novel aspect of the theory is the projection of the normal modes of a minimum onto the Qim path and the determination of turning points on V(Qim). From that projection, the change in tunneling upon mode excitation can be calculated. If the projection is zero, no enhancement of tunneling is predicted. In that case vibrationally adiabatic (VA) theory could apply. However, if the projection is large then VA theory is not applicable. The approach is applied to mode-specific tunneling in full-dimensional malonaldehyde, using an accurate full-dimensional potential energy surface. Results are in semi-quantitative agreement with experiment for modes that show large enhancement of the tunneling, relative to the ground state tunneling splitting. For the six out-of-plane modes, which have zero projection on the planar Qim path, VA theory does apply, and results from that theory agree qualitatively and even semi-quantitatively with experiment. We also verify the failure of simple VA theory for modes that show large enhancement of tunneling.
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Upregulated microRNA-301a in breast cancer promotes tumor metastasis by targeting PTEN and activating Wnt/?-catenin signaling.
Gene
PUBLISHED: 10-16-2013
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MicroRNAs (miRNAs) are strongly implicated in many cancers, including breast cancer. Recently, microRNA-301a (miR-301a) has been proved to play a substantial role in gastric cancer, but its functions in the context of breast cancer remain unknown. Here we report that miR-301a was markedly upregulated in primary tumor samples from patients with distant metastases and pro-metastatic breast cancer cell lines. Gain-of-function and loss-of-function studies showed that ectopic overexpression of miR-301a promoted breast cancer cell migration, invasion and metastasis both in vitro and in vivo. Notably, Wnt/?-catenin signaling was hyperactivated in metastatic breast cancer cells that express miR-301a, and mediated miR-301a-induced invasion and metastasis. Furthermore, miR-301a directly targeted and suppressed PTEN, one negative regulator of the Wnt/?-catenin signaling cascade. These results demonstrate that miR-301a maintains constitutively activated Wnt/?-catenin signaling by directly targeting PTEN, which promotes breast cancer invasion and metastasis. Taken together, our findings reveal a new regulatory mechanism of miR-301a and suggest that miR-301a might be a potential target in breast cancer therapy.
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Relationships between local geometrical features and hemodynamic flow properties.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 10-11-2013
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Stroke is among the leading causes of death and disability worldwide. Most strokes are ischemic, mostly caused by the blockage of a cerebral artery by a thrombotic embolus. Carotid atherosclerosis and the subsequent plaque rupture can be a major source of these emboli. It is well known that blood flow affects where atherosclerotic plaque will arise. In particular, vascular wall shear stress (WSS) has been linked to the initiation and progression of carotid plaque. However, it is difficult to measure WSS in vivo and it is time-consuming to compute WSS using computational fluid dynamics packages. The goals of this paper are (i) to identify a set of local geometric parameters that are correlated with WSS and (ii) to develop a regression model to predict WSS from the geometric parameters. We validated our regression model using the root mean squared error (RMSE), adjusted R(2) and Akaike information criterion (AIC). The experimental study involved six carotid arteries with the internal and external carotid arteries (ICA and ECA respectively) analyzed separately. The adjusted R(2)s for 9 of the 12 branches were higher than 0.8. Since the proposed local geometric parameters can be obtained efficiently, these parameters can potentially be used as carotid disease phenotypes that will allow for a much more cost-effective method to identify subjects with elevated stroke risk.
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Association between interleukin-6 gene polymorphisms and bone mineral density: a meta-analysis.
Genet Test Mol Biomarkers
PUBLISHED: 09-21-2013
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Background: Many studies have examined the association between interleukin-6 (IL-6) gene polymorphisms and bone mineral density (BMD). However, the results remain conflicting. To assess the relationship more precisely, a meta-analysis was performed. Methods: The PubMed, Embase, Chinese BioMedical Literature (CBM), Wanfang, and China National Knowledge Infrastructure (CNKI) database were searched for relevant articles published up to March 2013. Weighted mean difference (WMD) and 95% confidence interval (95% CI) were calculated using a fixed-effects or random-effects model. Results: A total of 16 articles with 11,957 subjects were investigated in this meta-analysis. Overall, -634C/G polymorphism was significantly associated with BMD at the femoral neck (WMD, -0.016?g/cm(2); 95% CI, -0.028 to -0.003?g/cm(2)), lumbar spine (WMD, -0.049?g/cm(2); 95% CI, -0.069 to -0.030?g/cm(2)), and whole body (WMD, -0.023?g/cm(2); 95% CI, -0.037 to -0.009?g/cm(2)) for GG versus CC+CG. In subgroup analyses stratified by ethnicity, individuals carrying -634GG genotype had a significantly lower mean BMD at any skeletal site examined, compared with individuals with -634CC or -634CG genotype in Asian populations. For -174G/C polymorphism, the BMD differences between CC+CG and GG genotype were 0.004?g/cm(2) at the distal radius (95% CI, 0.004 to 0.005?g/cm(2)), 0.011?g/cm(2) at the trochanter (95% CI, 0.002 to 0.020?g/cm(2)), and 0.017?g/cm(2) at the Wards triangle (95% CI, 0.003 to 0.032?g/cm(2)). No significant publication bias was observed in either the -634C/G or -174G/C polymorphism. Conclusions: This suggests that there are modest effects of the -634C/G and -174G/C polymorphisms on BMD. Large-scale and well-designed studies are required to further investigate gene-gene and gene-environment interactions on IL-6 polymorphisms and BMD in various populations.
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Calculations and measurements of the deuterium tunneling frequency in the propiolic acid-formic acid dimer and description of a newly constructed Fourier transform microwave spectrometer.
J Chem Phys
PUBLISHED: 09-07-2013
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The concerted proton tunneling frequency for the propiolic acid-formic acid dimer was calculated using a relaxed ab initio double-well potential in the imaginary-frequency mode of the saddle point, and new measurements were made for the deuterated propiolic acid-formic acid (ProOD-FAOD) isotopologue. It is important to have consistent calculated tunneling frequency values between normal and deuterated isotopologues since parameters can be readily adjusted to get good agreement with one isotopologue. High-resolution rotational spectra of deuterated (ProOD-FAOD) dimer were measured using a newly constructed Fourier Transform microwave spectrometer. The new spectrometer has mirror size: 30 cm in diameter with a radius of curvature of 59 cm and is equipped with multiple-FID data collection (5-10 FIDs for each gas pulse). For the deuterated (ProOD-FAOD) isotopologue, 45 rotational lines (a type: 34; b type: 11) were measured in the lowest tunneling states range between 6.5 GHz and 15.5 GHz. With the new high-resolution measurements of the tunneling doublets (b-dipole transitions), the double potential well responsible for the deuterium tunneling was depicted much more precisely. The two tunneling states are separated by 3.48 MHz. The rotational constants obtained in this work are quite helpful for further structure analysis as well.
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Habituation to organic acid anions induces resistance to acid and bile in Listeria monocytogenes.
Meat Sci.
PUBLISHED: 08-23-2013
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We evaluated the intrinsic and inducible resistance of four human pathogenic strains of Listeria monocytogenes to acid and bile, factors associated with virulence. Cells were grown in media at pH7.4, or in media at pH6.0 containing 0 (HCl control) or 4.75mM of different organic acids, harvested at stationary or mid log phase, and challenged for 1h in acid or bile. Stationary phase cells were intrinsically more resistant to either challenge than log phase cells, and large differences between strains were evident among the latter. Compared to the HCl control, habituation to log phase with organic acids induced significant (p<0.05) and meaningful (?1log) increases in acid resistance of three of four strains tested, and in bile resistance of two strains suggesting that exposure to organic acid anions may enhance virulence in L. monocytogenes.
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Early warning of illegal development for protected areas by integrating cellular automata with neural networks.
J. Environ. Manage.
PUBLISHED: 08-22-2013
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Ecological security has become a major issue under fast urbanization in China. As the first two cities in this country, Shenzhen and Dongguan issued the ordinance of Eco-designated Line of Control (ELC) to "wire" ecologically important areas for strict protection in 2005 and 2009 respectively. Early warning systems (EWS) are a useful tool for assisting the implementation ELC. In this study, a multi-model approach is proposed for the early warning of illegal development by integrating cellular automata (CA) and artificial neural networks (ANN). The objective is to prevent the ecological risks or catastrophe caused by such development at an early stage. The integrated model is calibrated by using the empirical information from both remote sensing and handheld GPS (global positioning systems). The MAR indicator which is the ratio of missing alarms to all the warnings is proposed for better assessment of the model performance. It is found that the fast urban development has caused significant threats to natural-area protection in the study area. The integration of CA, ANN and GPS provides a powerful tool for describing and predicting illegal development which is in highly non-linear and fragmented forms. The comparison shows that this multi-model approach has much better performances than the single-model approach for the early warning. Compared with the single models of CA and ANN, this integrated multi-model can improve the value of MAR by 65.48% and 5.17% respectively.
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Vibrational analysis of an ice Ih model from 0 to 4000 cm(-1) using the ab initio WHBB potential energy surface.
J Phys Chem B
PUBLISHED: 08-20-2013
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We present an analysis of the vibrational modes of a model of hexagonal ice, ice Ih, comprised of 192 monomers with a core region of 105 monomers, using the ab initio WHBB potential energy surface [Wang, Y.; Shepler, B.; Braams, B.; Bowman, J. M. J. Chem. Phys. 2011, 134, 094509]. A standard normal-mode analysis and a local-monomer normal-mode analysis of 105 core monomers are performed to obtain harmonic frequencies and state densities of the "pseudo-translation" (0-400 cm(-1)), "libration" (500-1100 cm(-1)), monomer bend fundamental (~1600 cm), and O-H stretch (~3000-3700 cm(-1)) bands. In addition, the coupled local-monomer model is used to obtain the vibrational density of states in the bend fundamental and O-H stretch regions. The harmonic and local-monomer vibrational density of states obtained from core monomers are in good agreement with those of inelastic neutron scattering spectra, especially the latter, which accounts for anharmonic coupling of monomer modes. Full deuteration is also considered, and the vibrational density of states is again compared to experiment, where good agreement is found.
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A framework for the co-registration of hemodynamic forces and atherosclerotic plaque components.
Physiol Meas
PUBLISHED: 08-14-2013
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Local hemodynamic forces, such as wall shear stress (WSS), are thought to trigger cellular and molecular mechanisms that determine atherosclerotic plaque vulnerability to rupture. Magnetic resonance imaging has emerged as a powerful tool to characterize human carotid atherosclerotic plaque composition and morphology, and to identify plaque features shown to be key determinants of plaque vulnerability. Image-based computational fluid dynamics has allowed researchers to obtain time-resolved WSS information of atherosclerotic carotid arteries. A deeper understanding of the mechanisms of initiation and progression of atherosclerosis can be obtained through the comparison of WSS and plaque composition and morphology. To date, however, advance in knowledge has been limited greatly due to the lack of a reliable infrastructure to perform such analysis. The aim of this study is to establish a framework that will allow for the co-registration and analysis of the three-dimensional distribution of WSS and plaque components and morphology. The use of this framework will lead to future studies targeted to determining the role of WSS in atherosclerotic plaque progression and vulnerability.
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Aptamers as theranostic agents: modifications, serum stability and functionalisation.
Sensors (Basel)
PUBLISHED: 08-07-2013
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Aptamers, and the selection process known as Systematic Evolution of Ligands by Exponential Enrichment (SELEX) used to generate them, were first described more than twenty years ago. Since then, there have been numerous modifications to the selection procedures. This review discusses the use of modified bases as a means of enhancing serum stability and producing effective therapeutic tools, as well as functionalising these nucleic acids to be used as potential diagnostic agents.
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Synthesis of D-mannose capped silicon nanoparticles and their interactions with MCF-7 human breast cancerous cells.
ACS Appl Mater Interfaces
PUBLISHED: 07-16-2013
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Silicon nanoparticles (SiNPs) hold prominent interest in various aspects of biomedical applications. For this purpose, surface functionalization of the NPs is essential to stabilize them, target them to specific disease area, and allow them to selectively bind to the cells or the bio-molecules present on the surface of the cells. However, no such functionalization has been explored with Si nanoparticles. Carbohydrates play a critical role in cell recognition. Here, we report the first synthesis of silicon nanoparticles functionalized with carbohydrates. In this study, stable and brightly luminescent d-Mannose (Man) capped SiNPs have been synthesized from amine terminated SiNPs and d-mannopyranoside acid. The surface functionalization is confirmed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and energy dispersive X-ray spectroscopy (EDX) studies. The mean diameter of the crystal core is 5.5 nm, as measured by transmission electron microscopy (TEM), while the hydrodynamic diameter obtained by dynamic light scattering (DLS) is 16 nm. The quantum yield (QY) of photoluminescence emission is found to be 11.5%, and the nanoparticles exhibit an exceptional stability over two weeks. The Man-capped SiNPs may prove to be valuable tools for further investigating glycobiological, biomedical, and material science fields. Experiments are carried out using Concanavalin A (ConA) as a target protein in order to prove the hypothesis. When Man functionalized SiNPs are treated with ConA, cross-linked aggregates are formed, as shown in TEM images as well as monitored by photoluminescence spectroscopy (PL). Man functionalized SiNPs can target cancerous cells. Visualization imaging of SiNPs in MCF-7 human breast cancer cells shows the fluorescence is distributed throughout the cytoplasm of these cells.
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Prevalence of polycystic ovary syndrome in women in China: a large community-based study.
Hum. Reprod.
PUBLISHED: 06-27-2013
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What is the prevalence of polycystic ovary syndrome (PCOS) in Han Chinese women from different communities?
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[Research progress on genome-wide association studies of colorectal cancer].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 06-27-2013
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Colorectal cancer (CRC), one of the most common malignant tumors, is caused both by environmental and genetic factors. Genetic factor plays an important role in the pathogenesis of CRC. Genome-wide association study (GWAS) is a new tool of genetic research. A series of susceptibility genes and loci of the complex diseases has been identified with GWAS strategy. In this article, the research progress on GWAS of CRC is reviewed, and the advantages and limitations of GWAS study as well as the prospective of its application are discussed.
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Effect of suspension method and aging time on meat quality of Chinese fattened cattle M. Longissimus dorsi.
Meat Sci.
PUBLISHED: 06-26-2013
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Objectives of the present study were to evaluate the effects of suspension method and aging time on quality traits of Chinese fattened cattle M. Longissimus dorsi (LD). At the end of the slaughter line, the right sides of carcasses were re-hung from the pelvic bone obturator foramen, while the left sides remained hung by Achilles tendon suspension (AS). LD muscles were aged for 1, 7, 14 and 21 days and were then evaluated for quality index. Pelvic suspension (PS) significantly decreased the WBSF of beef muscle at 1 d and 7 d postmortem compared with AS. The tenderness with PS at 7 d postmortem was similar with that of AS at 14 d. Moreover, PS increased sarcomere length and decreased purge loss of LD significantly. In addition, aging time had a significant effect on pH, meat color, Warner-Bratzler shear force, and myofibril fragmentation index of LD muscle. To conclude, PS is valuable to be introduced to the beef industry in China for rapid (within 7 days) improvement of beef tenderness and decreased aging time of Chinese fattened cattle.
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Inflammation and cancer stem cells.
Cancer Lett.
PUBLISHED: 06-21-2013
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Cancer stem cells are becoming recognised as being responsible for metastasis and treatment resistance. The complex cellular and molecular network that regulates cancer stem cells and the role that inflammation plays in cancer progression are slowly being elucidated. Cytokines, secreted by tumour associated immune cells, activate the necessary pathways required by cancer stem cells to facilitate cancer stem cells progressing through the epithelial-mesenchymal transition and migrating to distant sites. Once in situ, these cancer stem cells can secrete their own attractants, thus providing an environment whereby these cells can continue to propagate the tumour in a secondary niche.
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Identification of the Binding Site of an Allosteric Ligand Using STD-NMR, Docking, and CORCEMA-ST Calculations.
ChemMedChem
PUBLISHED: 06-14-2013
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Singling out the truth: A combined application of STD-NMR, molecular docking, and CORCEMA-ST calculations is described as an attractive, easily applicable tool for the identification and validation of the binding site for allosteric ligands, with potential application as an aid in drug discovery research.
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Authentication and recovery of medical diagnostic image using dual reversible digital watermarking.
J Nanosci Nanotechnol
PUBLISHED: 06-13-2013
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This paper proposes a new region-based tampering detection and recovering method that utilizes both reversible digital watermarking and quad-tree decomposition for medical diagnostic images authentication. Firstly, the quad-tree decomposition is used to divide the original image into blocks with high homogeneity, and then we computer pixels linear interpolation as each blocks recovery feature. Secondly, these recovery features as the first layer watermarking information is embedded by using simple invertible integer transformation. In order to enhance the proposed methods security, the logistic chaotic map is exploited to choose each blocks reference pixel. The second layer watermark comprises by the quad-tree information and essential parameters for extraction are embedded by LSB replacement. In the authentication phase, the embedded watermark is extracted and the source image is recovered, and the similar linear interpolation technique is utilized to get each blocks feature. Therefore, the tampering detection and localization can be achieved through comparing the extracted feature with the recomputed one, and the extracted feature can be used to recover those tampered regions with high similarity to their original state. Experimental results show that, compared with previous similar existing scheme, the proposed method not only achieves high embedding capacity and good visual quality of marked and restored image, but also has more accuracy for tampering detection.
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Enhanced photoluminescence and characterization of multicolor carbon dots using plant soot as a carbon source.
Talanta
PUBLISHED: 04-20-2013
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Carbon dots (C-dots) are a class of novel fluorescent nanomaterials, which have drawn great attention for their potential applications in bio-nanotechnology. Multicolor C-dots have been synthesized by chemical nitric acid oxidation using the reproducible plant soot as raw material. TEM analysis reveals that the prepared C-dots have an average size of 3.1 nm. The C-dots are well dispersed in aqueous solution and are strongly fluorescent under the irradiation of ultra-violet light. X-ray photoelectron spectroscopy characterization demonstrates that the O/C atomic ratio for C-dots change to from 0.207 to 0.436 due to the chemical oxidation process. The photo bleaching experiment reveals that the C-dots show excellent photostability as compared with the conventional organic dyes, fluorescein and rhodamine B. The fluorescence intensity of the C-dots did not change significantly in the pH range of 3-10. To further enhance the fluorescence quantum yield, the C-dots were surface modified with four types of passivation ligands, 4,7,10-trioxa-1,13-tridecanediamine (TTDDA), poly-L-lysine (PLL), cysteine and chitosan and the fluorescence quantum yields of the TTDDA, PLL, cysteine and chitosan passivated C-dots were improved 1.53-, 5.94-, 2.00- and 3.68-fold, respectively. Fourier-transform infrared (FTIR) spectra were employed to characterize the surface groups of the C-dots. The bio-application of the C-dots as fluorescent bio-probes was evaluated in cell imaging and ex vivo fish imaging, which suggests that the C-dots may have potential applications in biolabeling and bioimaging.
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[Impact of hepatitis B virus on sperm parameters and outcome of assisted reproductive technology].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 04-16-2013
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With the development of assisted reproductive technology (ART), more and more hepatitis B virus (HBV)-infected couples have their own children successfully; however,vertical transmission of HBV in ART, especially father-to-child transmission, cannot be avoided. The mechanism of attachment and penetration of HBV into human sperm is still not known. Therefore, understanding the state and mechanism of HBV infection of sperm and the impact of HBV on sperm parameters, following up the ART outcome in man with HBV infection are helpful to solve the fertility problem and to control father-to-child vertical HBV infection.
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Experimental and theoretical investigations of the dissociation energy (D0) and dynamics of the water trimer, (H2O)3.
J Phys Chem A
PUBLISHED: 04-15-2013
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We report a joint experimental-theoretical study of the predissociation dynamics of the water trimer following excitation of the hydrogen bonded OH-stretch fundamental. The bond dissociation energy (D0) for the (H2O)3 ? H2O + (H2O)2 dissociation channel is determined from fitting the speed distributions of selected rovibrational states of the water monomer fragment using velocity map imaging. The experimental value, D0 = 2650 ± 150 cm(-1), is in good agreement with the previously determined theoretical value, 2726 ± 30 cm(-1), obtained using an ab initio full-dimensional potential energy surface (PES) together with Diffusion Monte Carlo calculations [ Wang ; Bowman . J. Chem. Phys. 2011 , 135 , 131101 ]. Comparing this value to D0 of the dimer places the contribution of nonpairwise additivity to the hydrogen bonding at 450-500 cm(-1). Quasiclassical trajectory (QCT) calculations using this PES help elucidate the reaction mechanism. The trajectories show that most often one hydrogen bond breaks first, followed by breaking and re-forming of hydrogen bonds (often with different hydrogen bonds breaking) until, after many picoseconds, a water monomer is finally released. The translational energy distributions calculated by QCT for selected rotational levels of the monomer fragment agree with the experimental observations. The product translational and rotational energy distributions calculated by QCT also agree with statistical predictions. The availability of low-lying intermolecular vibrational levels in the dimer fragment is likely to facilitate energy transfer before dissociation occurs, leading to statistical-like product state distributions.
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The mismatch repair gene hPMS1 (human postmeiotic segregation1) is down regulated in oral squamous cell carcinoma.
Gene
PUBLISHED: 03-29-2013
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Genomic instability or microsatellite instability (MSI) was initially recognized in colonic carcinoma and subsequently in other tumors. MSI has been associated with mutations in genes that play a role in DNA replication and repair. In a previous study we detected MSI in 85% of young patients with OSCC and excluded the involvement of MMR genes hMLH1 and hMSH2. In the present study, we screened the mutation and expression status of the MMR genes hMSH3, hMSH6, hPMS1 and hPMS2 in OSCC and found expression of the hPMS1 protein to be down regulated. Genomic analysis of hPMS1 did not show any mutational changes in exonic or promoter regions. Expression of hPMS1 mRNA was not deregulated in either MSI positive or MSI negative tumor cell lines by Northern blot analysis. In contrast, analysis by Western blot showed that 100% of MSI positive tumor cell lines had decreased or no expression of hPMS1 while MSI negative cell lines had normal protein expression. Our data indicate that hPMS1 is most likely deregulated by post-transcriptional modification in OSCC while hMLH1 and hPMS2 has no detectable changes. Furthermore, our results are consistent with the hypothesis that hPMS1 is associated with MSI in OSCC.
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Impact of fly ash and phosphatic rock on metal stabilization and bioavailability during sewage sludge vermicomposting.
Bioresour. Technol.
PUBLISHED: 03-05-2013
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Sewage sludge (SS) was mixed with different proportions of fly ash (FA) and phosphoric rock (PR), as passivators, and earthworms, Eisenia fetida, were introduced to allow vermicomposting. The earthworm growth rates, reproduction rates, and metal (except Zn and Cd) concentrations were significantly higher in the vermireactors containing FA and PR than in the treatments without passivators. The total organic carbon (TOC) and total metal concentrations in the mixtures decreased, and the mixtures were brought to approximately pH 7 during vermicomposting. There were significant differences in the decreases in the metal bioavailability factors (BFs) between the passivator and control treatments, and adding 20% FA (for Cu and Zn) or 20% PR (for Pb, Cd, and As) to the vermicompost were the most effective treatments for mitigating metal toxicity. The BF appeared to be dependent on TOC in the all treatments, but was not closely dependent on pH in the different vermibeds.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.