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Find video protocols related to scientific articles indexed in Pubmed.
Influence of surface cracks on laser-induced damage resistance of brittle KH2PO4 crystal.
Opt Express
PUBLISHED: 11-18-2014
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Single point diamond turning (SPDT) currently is the leading finishing method for achieving ultra-smooth surface on brittle KH2PO4 crystal. In this work, the light intensification modulated by surface cracks introduced by SPDT cutting is numerically simulated using finite-difference time-domain algorithm. The results indicate that the light intensification caused by surface cracks is wavelength, crack geometry and position dependent. Under the irradiation of 355nm laser, lateral cracks on front surfaces and conical cracks on both front and rear surfaces can produce light intensification as high as hundreds of times, which is sufficient to trigger avalanche ionization and finally lower the laser damage resistance of crystal components. Furthermore, we experimentally tested the laser-induced damage thresholds (LIDTs) on both crack-free and flawed crystal surfaces. The results imply that brittle fracture with a series of surface cracks is the dominant source of laser damage initiation in crystal components. Due to the negative effect of surface cracks, the LIDT on KDP crystal surface could be sharply reduced from 7.85J/cm2 to 2.33J/cm2 (355nm, 6.4ns). In addition, the experiment of laser-induced damage growth is performed and the damage growth behavior agrees well with the simulation results of light intensification caused by surface cracks with increasing crack depths.
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Molecular Template-Directed Synthesis of Microporous Polymer Networks for Highly Selective CO2 Capture.
ACS Appl Mater Interfaces
PUBLISHED: 11-18-2014
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Porous polymer networks have great potential in various applications including carbon capture. However, complex monomers and/or expensive catalysts are commonly used for their synthesis, which makes the process complicated, costly, and hard to scale up. Herein, we develop a molecular template strategy to fabricate new porous polymer networks by a simple nucleophilic substitution reaction of two low-cost monomers (i.e., chloromethylbenzene and ethylene diamine). The polymerization reactions can take place under mild conditions in the absence of any catalysts. The resultant materials are interconnected with secondary amines and show well-defined micropores due to the structure-directing role of solvent molecules. These properties make our materials highly efficient for selective CO2 capture, and unusually high CO2/N2 and CO2/CH4 selectivities are obtained. Furthermore, the adsorbents can be completely regenerated under mild conditions. Our materials may provide promising candidates for selective capture of CO2 from mixtures such as flue gas and natural gas.
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Designing single- and multiple-shell sampling schemes for diffusion MRI using spherical code.
Med Image Comput Comput Assist Interv
PUBLISHED: 10-17-2014
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In diffusion MRI (dMRI), determining an appropriate sampling scheme is crucial for acquiring the maximal amount of information for data reconstruction and analysis using the minimal amount of time. For single-shell acquisition, uniform sampling without directional preference is usually favored. To achieve this, a commonly used approach is the Electrostatic Energy Minimization (EEM) method introduced in dMRI by Jones et al. However, the electrostatic energy formulation in EEM is not directly related to the goal of optimal sampling-scheme design, i.e., achieving large angular separation between sampling points. A mathematically more natural approach is to consider the Spherical Code (SC) formulation, which aims to achieve uniform sampling by maximizing the minimal angular difference between sampling points on the unit sphere. Although SC is well studied in the mathematical literature, its current formulation is limited to a single shell and is not applicable to multiple shells. Moreover, SC, or more precisely continuous SC (CSC), currently can only be applied on the continuous unit sphere and hence cannot be used in situations where one or several subsets of sampling points need to be determined from an existing sampling scheme. In this case, discrete SC (DSC) is required. In this paper, we propose novel DSC and CSC methods for designing uniform single-/multi-shell sampling schemes. The DSC and CSC formulations are solved respectively by Mixed Integer Linear Programming (MILP) and a gradient descent approach. A fast greedy incremental solution is also provided for both DSC and CSC. To our knowledge, this is the first work to use SC formulation for designing sampling schemes in dMRI. Experimental results indicate that our methods obtain larger angular separation and better rotational invariance than the generalized EEM (gEEM) method currently used in the Human Connectome Project (HCP).
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An Acentric Calcium Borate Ca2[B5O9]·(OH)·H2O: Synthesis, Structure, and Nonliner Optical Property.
Inorg Chem
PUBLISHED: 10-15-2014
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A novel noncentrosymmetric calcium borate, Ca2[B5O9]·(OH)·H2O (1), was synthesized under solvothermal condition using mixed solvents of pyridine and H2O. Compound 1 crystallizes in the monoclinic space group Cc. Its structure contains [B5O12] units and features a three-dimensional (3D) pcu net with nine-membered ring (9-MR) channels along the b-axis, where the Ca(2+) cations, OH(-) ions, and H2O molecules are located. Each Ca polyhedron shares three edges and one vertex with four neighbors to form a 3D dia Ca-O network. The pcu B-O net and dia Ca-O net are further interpenetrated to give the final denser net. The second harmonic generation (SHG) measurement shows that compound 1 is a type I phase-matchable material with a strong SHG response of ?3 times that of KH2PO4. In addition, it exhibits a wide transparency range with a short UV cutoff edge below 200 nm. These results reveal that the compound is a potential deep-UV nonlinear optical material. The Vienna ab initio theoretical studies indicate the good SHG response is derived from the synergistic effect of the ?-conjugated systems of BO3 groups and distorted CaO9 polyhedra.
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[DAB2IP expression in bladder transitional cell carcinoma and its correlation with clinical outcome].
Sichuan Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 10-08-2014
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To investigate the expression of DAB2IP in bladder transitional cell carcinoma (BTCC) and its correlation with clinical characteristics and prognosis of BTCC patients.
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Visual Synchronous Exchange of Metal Nodes and Counteranions Constituting a Cobalt(II) Coordination Polymer.
Inorg Chem
PUBLISHED: 09-26-2014
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A solid-state simultaneous exchange of metal nodes and counteranions based on a cobalt(2+) coordination polymer is reported for the first time. The ion-exchange process is visual, and the structural integrity of the cobalt(2+) coordination polymer is maintained during the ion-exchange process.
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Shenqi Fuzheng Injection () for advanced gastric cancer: A systematic review of randomized controlled trials.
Chin J Integr Med
PUBLISHED: 09-23-2014
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To evaluate the effectiveness of Shenqi Fuzheng Injection (, SFI) combined with chemotherapy for advanced gastric cancer.
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Ab initio Kinetic Monte Carlo simulations of dissolution at the NaCl-water interface.
Phys Chem Chem Phys
PUBLISHED: 09-18-2014
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We have used ab initio molecular dynamics (AIMD) simulations to study the interaction of water with the NaCl surface. As expected, we find that water forms several ordered hydration layers, with the first hydration layer having water molecules aligned so that oxygen atoms are on average situated above Na sites. In an attempt to understand the dissolution of NaCl in water, we have then combined AIMD with constrained barrier searches, to calculate the dissolution energetics of Na(+) and Cl(-) ions from terraces, steps, corners and kinks of the (100) surface. We find that the barrier heights show a systematic reduction from the most stable flat terrace sites, through steps to the smallest barriers for corner and kink sites. Generally, the barriers for removal of Na(+) ions are slightly lower than for Cl(-) ions. Finally, we use our calculated barriers in a Kinetic Monte Carlo as a first order model of the dissolution process.
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Peroxisomal Biogenesis in Ischemic Brain.
Antioxid. Redox Signal.
PUBLISHED: 09-17-2014
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Abstract Aims: Peroxisomes are highly adaptable and dynamic organelles, adjusting their size, number, and enzyme composition to changing environmental and metabolic demands. We determined whether peroxisomes respond to ischemia, and whether peroxisomal biogenesis is an adaptive response to cerebral ischemia. Results: Focal cerebral ischemia induced peroxisomal biogenesis in peri-infarct neurons, which was associated with a corresponding increase in peroxisomal antioxidant enzyme catalase. Peroxisomal biogenesis was also observed in primary cultured cortical neurons subjected to ischemic insult induced by oxygen-glucose deprivation (OGD). A catalase inhibitor increased OGD-induced neuronal death. Moreover, preventing peroxisomal proliferation by knocking down dynamin-related protein 1 (Drp1) exacerbated neuronal death induced by OGD, whereas enhancing peroxisomal biogenesis pharmacologically using a peroxisome proliferator-activated receptor-alpha agonist protected against neuronal death induced by OGD. Innovation: This is the first documentation of ischemia-induced peroxisomal biogenesis in mammalian brain using a combined in vivo and in vitro approach, electron microscopy, high-resolution laser-scanning confocal microscopy, and super-resolution structured illumination microscopy. Conclusion: Our findings suggest that neurons respond to ischemic injury by increasing peroxisome biogenesis, which serves a protective function, likely mediated by enhanced antioxidant capacity of neurons. Antioxid. Redox Signal. 00, 000-000.
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CCR5 Blockade Promotes M2 Macrophage Activation and Improves Locomotor Recovery After Spinal Cord Injury in Mice.
Inflammation
PUBLISHED: 09-13-2014
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Spinal cord injury (SCI) is considered to be primarily associated with loss of motor function and leads to activate diverse cellular mechanisms in the central nervous system to attempt to repair the damaged spinal cord tissue. Chemokine Receptor 5 (CCR5), a major co-receptor for macrophage-tropic human immunodeficiency viruses, is expressed on the surface of monocytes/macrophages, dendritic cells, activated T cells, and NK cells. Recent papers have indicated the important role of CCR5 in SCI, but the mechanism is still unknown. In our current study, CCR5 blockade displayed increased myelin sparring and enhanced SC repair process. The number of CD4(+) T cells, CD8(+) T cells, Ly6G(+) neutrophils and CD11b(+) macrophages were all significantly lower in the anti-CCR5 group than that in the control group after SCI. The IL-4 and IL-13 levels in anti-CCR5 group were markedly higher than that in control group after SCI. Correspondingly, the anti-CCR5-treated group showed increased numbers of Arg1- or CD206-expressing macrophages compared with the control IgG group. Furthermore, CCR5 blockade promoted PPAR? activation, and the increased numbers of M2 macrophages induced by CCR5 blockade were both reversed with additional PPAR? antagonist treatment. In conclusion, our present work provides evidence to support the concept that CCR5 blockade promotes M2 macrophage activation and improves locomotor recovery after SCI in mice.
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Expression of polycystins and fibrocystin on primary cilia of lung cells.
Biochem. Cell Biol.
PUBLISHED: 09-12-2014
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Mutations in polycystin-1, polycystin-2, or fibrocystin account for autosomal dominant or recessive polycystic kidney disease. Renal cystogenesis is linked to abnormal localization and function of these cystoproteins in renal primary cilia. They are also expressed in extrarenal tissues in which their functions are unclear. Here we found that human type-II alveolar epithelial A549, airway submucosal Calu-3 cells, and rat bronchioles contain primary or multiple cilia in which we detected these cystoproteins. At sub-confluency, polycystin-1 was expressed on plasma membrane, while polycystin-2 was localized to the ER of resting cells. Both polycystins were detected on the spindle and mid-body of mitotic cells, while fibrocystin was on centrosome throughout cell cycle. Polycystins and fibrocystin may participate in regulating mucociliary sensing and transport within pulmonary airways.
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The interleukin-10-1082A>G polymorphism and lymphoma risk: a meta-analysis.
Cancer Biomark
PUBLISHED: 08-30-2014
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The Interleukin-10 (IL-10) gene polymorphism (-1082 A>G) has been linked to the risk of developing lymphoma, but the available results were inconsistent. To derive a more precise estimation, we performed a meta-analysis.
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MiRNA-15a mediates cell cycle arrest and potentiates apoptosis in breast cancer cells by targeting synuclein-?.
Asian Pac. J. Cancer Prev.
PUBLISHED: 08-30-2014
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Recent studies have indicated that microRNA-15a (miR-15a) is dysregulated in breast cancer (BC). We aimed to evaluate the expression of miR-15a in BC tissues and corresponding para-carcinoma tissues. We also focused on effects of miR-15a on cellular behavior of MDA-MB-231 and expression of its target gene synuclein-? (SNCG).
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Data-Dependent Hashing Based on p-Stable Distribution.
IEEE Trans Image Process
PUBLISHED: 08-27-2014
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The p-stable distribution is traditionally used for data-independent hashing. In this paper, we describe how to perform data-dependent hashing based on p-stable distribution. We commence by formulating the Euclidean distance preserving property in terms of variance estimation. Based on this property, we develop a projection method, which maps the original data to arbitrary dimensional vectors. Each projection vector is a linear combination of multiple random vectors subject to p-stable distribution, in which the weights for the linear combination are learned based on the training data. An orthogonal matrix is then learned data-dependently for minimizing the thresholding error in quantization. Combining the projection method and orthogonal matrix, we develop an unsupervised hashing scheme, which preserves the Euclidean distance. Compared with data-independent hashing methods, our method takes the data distribution into consideration and gives more accurate hashing results with compact hash codes. Different from many data-dependent hashing methods, our method accommodates multiple hash tables and is not restricted by the number of hash functions. To extend our method to a supervised scenario, we incorporate a supervised label propagation scheme into the proposed projection method. This results in a supervised hashing scheme, which preserves semantic similarity of data. Experimental results show that our methods have outperformed several state-of-the-art hashing approaches in both effectiveness and efficiency.
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Associations between extreme precipitation and childhood hand, foot and mouth disease in urban and rural areas in Hefei, China.
Sci. Total Environ.
PUBLISHED: 08-23-2014
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Understanding the relationship between extreme weather events and childhood hand, foot and mouth disease (HFMD) is important in the context of climate change. This study aimed to quantify the relationship between extreme precipitation and childhood HFMD in Hefei, China, and further, to explore whether the association varied across urban and rural areas.
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Plerixafor is effective given either preemptively or as a rescue strategy in poor stem cell mobilizing patients with multiple myeloma.
Transfusion
PUBLISHED: 08-13-2014
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Harvest of more than one CD34+ stem cell transplant has become the standard, to ensure the option for a second autologous transplantation in patients with relapsed or progressive multiple myeloma (MM). Additional administration of the CXCR-4 inhibitor plerixafor has been shown to increase the efficiency of CD34+ stem cell harvest. However, the algorithm when to apply plerixafor is still under debate.
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Non-Negative Spherical Deconvolution (NNSD) for estimation of fiber Orientation Distribution Function in single-/multi-shell diffusion MRI.
Neuroimage
PUBLISHED: 08-07-2014
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Spherical Deconvolution (SD) is commonly used for estimating fiber Orientation Distribution Functions (fODFs) from diffusion-weighted signals. Existing SD methods can be classified into two categories: 1) Continuous Representation based SD (CR-SD), where typically Spherical Harmonic (SH) representation is used for convenient analytical solutions, and 2) Discrete Representation based SD (DR-SD), where the signal profile is represented by a discrete set of basis functions uniformly oriented on the unit sphere. A feasible fODF should be non-negative and should integrate to unity throughout the unit sphere S(2). However, to our knowledge, most existing SH-based SD methods enforce non-negativity only on discretized points and not the whole continuum of S(2). Maximum Entropy SD (MESD) and Cartesian Tensor Fiber Orientation Distributions (CT-FOD) are the only SD methods that ensure non-negativity throughout the unit sphere. They are however computational intensive and are susceptible to errors caused by numerical spherical integration. Existing SD methods are also known to overestimate the number of fiber directions, especially in regions with low anisotropy. DR-SD introduces additional error in peak detection owing to the angular discretization of the unit sphere. This paper proposes a SD framework, called Non-Negative SD (NNSD), to overcome all the limitations above. NNSD is significantly less susceptible to the false-positive peaks, uses SH representation for efficient analytical spherical deconvolution, and allows accurate peak detection throughout the whole unit sphere. We further show that NNSD and most existing SD methods can be extended to work on multi-shell data by introducing a three-dimensional fiber response function. We evaluated NNSD in comparison with Constrained SD (CSD), a quadratic programming variant of CSD, MESD, and an L1-norm regularized non-negative least-squares DR-SD. Experiments on synthetic and real single-/multi-shell data indicate that NNSD improves estimation performance in terms of mean difference of angles, peak detection consistency, and anisotropy contrast between isotropic and anisotropic regions.
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Bmi-1 induces radioresistance by suppressing senescence in human U87 glioma cells.
Oncol Lett
PUBLISHED: 07-29-2014
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Radiotherapy is the main locoregional control modality for a number of types of malignant tumors, including glioblastoma. However, radiotherapy fails to prevent recurrence in numerous patients due to the intrinsic radioresistance of cancer cells. Cell senescence is significant in tumor suppressor mechanisms and is closely associated with the radioresistance of cancer cells. Bmi-1 has been proposed to be an oncogene that can induce anti-senescence in tumor cells. The present study investigated the response of U87 glioma cells to radiation exposure and the role of Bmi-1 in the response following radiotherapy. Cell apoptosis and cell cycle distribution were assessed using flow cytometry, and a SA-?-Gal stain was used to observe the senescence ratio of U87 cells following radiation. The expression of Bmi-1 in U87 cells exposed to different doses of radiation was evaluated by western blot analysis. X-ray radiation was found to inhibit U87 cell proliferation through the induction of senescence rather than apoptosis. Following exposure to radiation, the cell cycle distribution was dysregulated, with an increased number of cells in the G2/M phase, and the expression of Bmi-1 was upregulated, particularly when a dose of ?6 Gy was administered. The results indicated that senescence is the main mechanism by which U87 cell growth is inhibited following radiation. In addition, Bmi-1 may be significant in increasing the radioresistance of glioma cells by enabling cell senescence.
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[Studies on effects of Achyranthes bidentata on tongsaimai pellets main active ingredients chlorogenic acid, isoliquiritin, harpagoside and glycyrrhizin in vivo pharmacokinetics].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 07-22-2014
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To study on the effects of Achyranthes bidentata on Tongsaimai pellets main active ingredients chlorogenic acid, isoliquiritin, harpagoside and glycyrrhizin in rats in vivo pharmacokinetic behaviors, a method for the simultaneous determination of chlorogenic acid, isoliquiritin, harpagoside and liquiritigenin in rat plasma was established by UPLC-MS/MS. The analysis was performed on a waters Acquity BEH C18 column (2.1 mm x 100 mm, 1.7 microm) with the mixture of acetonitrile and 0.1% formic acid/water as mobile phase, and the gradient elution at a flow rate of 0.3 mL x min(-1). The analytes were detected by tandem mass spectrometry with the electrospray ionization (ESI) source and in the multiple reaction monitoring (MRM) mode. It turned out that the analytes of Tongsaimai pellets groups C(max) and AUC(Q-infinity) values were higher than that with A. bidentata group, and the C(max) values of chlorogenic acid had significantly difference (P < 0.05), the AUC(0-infinity) values of chlorogenic acid and glycyrrhizin had significantly difference (P < 0.05); The T(max) and CL values of two groups had no significantly difference. Results showed that the established method was specific, rapid, accurate and sensitive for the studies of Tongsaimai pellets four main active ingredients in rat in vivo pharmacokinetic, and A. bidentata have varying degrees of effects on Tongsaimai pellets four main active ingredients in rat in vivo pharmacokinetic behaviors.
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Design of an Elliptic Curve Cryptography processor for RFID tag chips.
Sensors (Basel)
PUBLISHED: 07-09-2014
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Radio Frequency Identification (RFID) is an important technique for wireless sensor networks and the Internet of Things. Recently, considerable research has been performed in the combination of public key cryptography and RFID. In this paper, an efficient architecture of Elliptic Curve Cryptography (ECC) Processor for RFID tag chip is presented. We adopt a new inversion algorithm which requires fewer registers to store variables than the traditional schemes. A new method for coordinate swapping is proposed, which can reduce the complexity of the controller and shorten the time of iterative calculation effectively. A modified circular shift register architecture is presented in this paper, which is an effective way to reduce the area of register files. Clock gating and asynchronous counter are exploited to reduce the power consumption. The simulation and synthesis results show that the time needed for one elliptic curve scalar point multiplication over GF(2163) is 176.7 K clock cycles and the gate area is 13.8 K with UMC 0.13 ?m Complementary Metal Oxide Semiconductor (CMOS) technology. Moreover, the low power and low cost consumption make the Elliptic Curve Cryptography Processor (ECP) a prospective candidate for application in the RFID tag chip.
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Which is the best Chinese herb injection based on the FOLFOX regimen for gastric cancer? A network meta- analysis of randomized controlled trials.
Asian Pac. J. Cancer Prev.
PUBLISHED: 07-08-2014
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Few studies have directly compared clinical efficacy and safety among Chinese herb injections (CHIs) for gastric cancer (GC). The present study aimed to compare CHIs combined with FOLFOX regimens for GC to show which provides the best CHIs results.
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Aberrant methylation of genes in sputum samples as diagnostic biomarkers for non-small cell lung cancer: a meta-analysis.
Asian Pac. J. Cancer Prev.
PUBLISHED: 06-28-2014
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We aimed to comprehensively review the evidence for using sputum DNA to detect non-small cell lung cancer (NSCLC).
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Temperature variation between neighboring days and mortality: a distributed lag non-linear analysis.
Int J Public Health
PUBLISHED: 05-30-2014
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To investigate whether a sudden temperature change between neighboring days has significant impact on mortality.
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Genome Sequence of Candida tropicalis no. 121, Used for RNA Production.
Genome Announc
PUBLISHED: 05-17-2014
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We report here the complete genome sequence of Candida tropicalis no. 121. C. tropicalis no. 121 is a high-RNA-producing strain obtained by mutagenesis in our laboratory. The complete genome sequence was determined using the Illumina HiSeq 2000 and contains 6,415 genes. The genome size of C. tropicalis no. 121 is >15.3 Mb.
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Identification of Homer1 as a potential prognostic marker for intrahepatic cholangiocarcinoma.
Asian Pac. J. Cancer Prev.
PUBLISHED: 05-13-2014
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The aim of the present study was to analyze whether Homer1 is a potential prognostic marker for intrahepatic cholangiocarcinoma (ICC).
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Dissolution of NaCl nanocrystals: an ab initio molecular dynamics study.
Phys Chem Chem Phys
PUBLISHED: 04-16-2014
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The dissolution of NaCl has been systematically investigated by employing ab initio molecular dynamics (AIMD) on different NaCl nanocrystals as well as on a surface system immersed in water. We discovered a complex dissolution process simultaneously involving multiple ions initiated at the corner sites of the crystal. Our simulations indicated a difference in the dissolution rates of sodium and chlorine. While sodiums readily became partially solvated, chlorines more frequently transitioned into the fully solvated state leading to an overall greater dissolution rate for Cl. We determined that this difference arises due to faster water mediated elongations of individual ionic bonds to Na, but a significantly slower process for the last bond in comparison to Cl. In an attempt to investigate this phenomenon further, we performed metadynamics based free energy simulations on a surface slab presenting corner sites similar to those in cubic crystals, aiming to extract the dissolution free energy profile of corner ions. In qualitative agreement with the nanocrystal simulations, this revealed a shallower first free energy minimum for Na, but no statistically significant difference in the corresponding barriers and inconclusive results for the latter stage. Finally, simulations of smaller NaCl crystals illustrated how dissolution proceeds beyond the point of crystal lattice collapse, highlighting the strength of solvated ion interactions.
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A centennial record of anthropogenic impacts and extreme weather events in southwestern Taiwan: evidence from sedimentary molecular markers in coastal margin.
Mar. Pollut. Bull.
PUBLISHED: 03-31-2014
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A 100-year history of human and natural disturbances in southwestern Taiwan was reconstructed using a suite of molecular markers in four dated sediment cores from the upper slope region off the Gaoping River mouth. Trends in polycyclic aromatic hydrocarbons (PAHs) tracked Taiwan's industrialization/urbanization starting in the 1970s, and the enactment of environmental regulatory policies thereafter. The predominant pyrogenic sources include vehicular, smelter, and coal combustion but spatial differences are observed among sub-regions of the shelf. Profiles of lignin oxidation products (LOPs) point to a significant increase in terrestrial organic matter inputs driven by land development after the 1970s. Low lignin diagenetic signature ratios [(Ad/Al)v] in all sediments suggest quick transport of fresh plant material from land to sea via mountainous rivers. Shifts in PAHs, LOPs, and radionuclides in recent sediments reveal the deposition of turbidites resulting from typhoon-induced floods. Multiproxy analysis illustrates the interplay between anthropogenic activities and natural processes.
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Two series of sandwich frameworks based on two different kinds of nanosized lanthanide(III) and copper(I) wheel cluster units.
Chemistry
PUBLISHED: 03-29-2014
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Two series of sandwich frameworks, [La6(?3-OH)2(ox)3L12Cu11(?3-X)6(?2-X)3]·8H2O (X=Br/Cl, FJ-21 a/b; L=4-pyridin-4-yl-benzonate; ox=oxalate) and [Ln4(OAc)3-(H2O)4L9][Cu(?3-I)]@[Cu10(?3-I)(?4-I)6(?5-I)3]·7H2O (Ln=Pr/Nd/Sm/Eu, FJ-22 a/b/c/d; OAc=acetate) have been hydrothermally prepared. These sandwich frameworks are assembled by two different kinds of nanosized lanthanide-(III) and copper(I) wheel cluster units, La18 and 3Cu@Cu24 in FJ-21, Ln24 and Cu2@Cu24 in FJ-22. The synergistic coordination between organic ligands, L and oxalate/acetate, leads to the formation of La18 and Ln24 wheels, while the synergistic coordination between organic L and inorganic Br/I ligands results in 3Cu@Cu24 and Cu2@Cu24 wheels for FJ-21 and FJ-22, respectively. Thus, two types of synergistic coordination between two different organic ligands, as well as inorganic and organic ligands are simultaneously observed in FJ-21 and FJ-22.
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Oxygen and methanol mediated irreversible coordination polymer structural transformation from a 3D Cu(I)-framework to a 1D Cu(II)-chain.
Chem. Commun. (Camb.)
PUBLISHED: 03-19-2014
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An interesting irreversible structural transformation visible to the naked-eye occurs when a 3D Cu(I)-polymeric complex Cu2L(NO3)2(DMF)0.4 (1) is suspended in CH3OH in air to produce a 1D-Cu(II) polymeric complex Cu(?-OCH3)(L)(NO3) (2) (L = 1,2-bis[4-(pyrimidin-4-yl)phenoxy]ethane). The transformation mechanism from 1 to 2 was also investigated.
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CaMKK?-dependent activation of AMP-activated protein kinase is critical to suppressive effects of hydrogen sulfide on neuroinflammation.
Antioxid. Redox Signal.
PUBLISHED: 03-13-2014
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The manner in which hydrogen sulfide (H2S) suppresses neuroinflammation is poorly understood. We investigated whether H2S polarized microglia to an anti-inflammatory (M2) phenotype by activating AMP-activated protein kinase (AMPK).
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Multi-atlas based representations for Alzheimer's disease diagnosis.
Hum Brain Mapp
PUBLISHED: 03-12-2014
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Brain morphometry based classification from magnetic resonance (MR) acquisitions has been widely investigated in the diagnosis of Alzheimer's disease (AD) and its prodromal stage, i.e., mild cognitive impairment (MCI). In the literature, a morphometric representation of brain structures is obtained by spatial normalization of each image into a common space (i.e., a pre-defined atlas) via non-linear registration, thus the corresponding regions in different brains can be compared. However, representations generated from one single atlas may not be sufficient to reveal the underlying anatomical differences between the groups of disease-affected patients and normal controls (NC). In this article, we propose a different methodology, namely the multi-atlas based morphometry, which measures morphometric representations of the same image in different spaces of multiple atlases. Representations generated from different atlases can thus provide the complementary information to discriminate different groups, and also reduce the negative impacts from registration errors. Specifically, each studied subject is registered to multiple atlases, where adaptive regional features are extracted. Then, all features from different atlases are jointly selected by a correlation and relevance based scheme, followed by final classification with the support vector machine (SVM). We have evaluated the proposed method on 459 subjects (97 AD, 117 progressive-MCI (p-MCI), 117 stable-MCI (s-MCI), and 128 NC) from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database, and achieved 91.64% for AD/NC classification and 72.41% for p-MCI/s-MCI classification. Our results clearly demonstrate that the proposed multi-atlas based method can significantly outperform the previous single-atlas based methods.
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Improvement of functional recovery by chronic metformin treatment is associated with enhanced alternative activation of microglia/macrophages and increased angiogenesis and neurogenesis following experimental stroke.
Brain Behav. Immun.
PUBLISHED: 03-05-2014
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Acute AMPK activation exacerbates ischemic brain damage experimentally. Paradoxically, the clinical use of an AMPK activator metformin reduces the incidence of stroke. We investigated whether post-stroke chronic metformin treatment promotes functional recovery and tissue repair via an M2-polarization mechanism following experimental stroke. Mice were randomly divided to receive metformin or vehicle daily beginning at 24h after middle cerebral artery occlusion (MCAO). Neurological deficits were monitored for 30days following MCAO. To characterize the polarization of the microglia and infiltrating macrophages, the expression of the M1 and M2 signature genes was analyzed with qPCR, ELISA and immunohistochemistry. Post-MCAO angiogenesis and neurogenesis were examined immunohistochemically. An in vitro angiogenesis model was employed to examine whether metformin promoted angiogenesis in a M2 polarization-dependent manner. Post-stroke chronic metformin treatment had no impact on acute infarction but enhanced cerebral AMPK activation, promoted functional recovery and skewed the microglia/macrophages toward an M2 phenotype following MCAO. Metformin also significantly increased angiogenesis and neurogenesis in the ischemic brain. Consistently, metformin-induced M2 polarization of BV2 microglial cells depended on AMPK activation in vitro. Furthermore, treatment of brain endothelial cells with conditioned media collected from metformin-polarized BV2 cells promoted angiogenesis in vitro. In conclusion, post-stroke chronic metformin treatment improved functional recovery following MCAO via AMPK-dependent M2 polarization. Modulation of microglia/macrophage polarization represents a novel therapeutic strategy for stroke.
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Hydrogen sulfide protects blood-brain barrier integrity following cerebral ischemia.
J. Neurochem.
PUBLISHED: 02-13-2014
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By using two structurally unrelated hydrogen sulfide (H2 S) donors 5-(4-methoxyphenyl) -3H-1, 2-dithiole-3-thione (ADT) and sodium hydrosulfide (NaHS), this study investigated if H2 S protected blood-brain barrier (BBB) integrity following middle cerebral artery occlusion (MCAO). ICR mice underwent MCAO and received H2 S donors at 3 h after reperfusion. Infarction, neurological scores, brain edema, Evans blue (EB) extravasation, and tight junction protein expression were examined at 48 h after MCAO. We also investigated if ADT protected BBB integrity by suppressing post-ischemic inflammation-induced Matrix Metalloproteimase-9 (MMP9) and Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX). ADT increased blood H2 S concentrations, decreased infarction, and improved neurological deficits. Particularly, ADT reduced EB extravasation, brain edema and preserved expression of tight junction proteins in the ischemic brain. NaHS also increased blood H2 S levels and reduced EB extravasation following MCAO. Moreover, ADT inhibited expression of pro-inflammatory markers induced Nitric Oxide Synthase (iNOS) and IL-1? while enhanced expression of anti-inflammatory markers arginase 1 and IL-10 in the ischemic brain. Accordingly, ADT attenuated ischemia-induced expression and activity of MMP9. Moreover, ADT reduced NOX-4 mRNA expression, NOX activity, and inhibited nuclear translocation of Nuclear Factor Kappa-B (NF-?B) in the ischemic brain. In conclusion, H2 S donors protected BBB integrity following experimental stroke possibly by acting through NF-?B inhibition to suppress neuroinflammation induction of MMP9 and NOX4-derived free radicals. To determine H2 S effects on blood-brain barrier (BBB) disruption following stroke, we used two structurally unrelated H2 S donors ADT and NaHS. Both ADT and NaHS remarkably protected BBB integrity following experimental stroke. The slow-releasing donor ADT also reduced post-ischemic inflammation-induced expression and activity of MMP9 and NOX4 in the ischemic brain possibly by inhibiting NF-?B activation.
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20S-Ginsenoside Rh2 induces apoptosis in human Leukaemia Reh cells through mitochondrial signaling pathways.
Biol. Pharm. Bull.
PUBLISHED: 02-05-2014
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20(S)-Ginsenoside Rh2 (GRh2) and ginsenoside Rg3 (GRg3) are members of the protopanaxadiol family and have been investigated for possible chemopreventive activity. This study explored the biological and apoptotic mechanisms induced by 20(S)-GRh2 in human acute leukaemia line-Reh cells. Reh cells were treated with different concentration of 20(S)-GRh2 in vitro. Cell viability was determined by Cell Counting Kit-8 and Annexin V/7-AAD assays. Mitochondrial membrane potential (MMP) was examined through JC-1 staining. Activation of caspases associated with the mitochondria-mediated apoptosis pathway was determined by Western blot. We observed that survival of Reh cells decreased after exposure to 20(S)-GRh2 in a concentration-dependent manner. Moreover, 20(S)-GRh2 can induce mitochondria depolarization of Reh cells as evident in the shift in JC-1 fluorescence from red to green. In addition, 20(S)-GRh2 induced the release of mitochondrial cytochrome c and activation of caspase-9 and caspase-3 in Reh cells. These results indicate that 20(S)-GRh2 could induce apoptosis through the mitochondrial pathway, demonstrating its potential as a chemotherapeutic agent for leukaemia therapy.
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Association between serum free fatty acid levels and possible related factors in patients with type 2 diabetes mellitus and acute myocardial infarction.
BMC Cardiovasc Disord
PUBLISHED: 01-24-2014
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Free fatty acids (FFAs) play importance roles in the development of diabetes and cardiovascular diseases. We measured serum FFA levels from type 2 diabetes mellitus (T2DM) and acute myocardial infarction (AMI) patients and assay the correlation between serum FFA levels and related factors. The present study was undertaken to investigate a possible relation between the changes in serum free fatty acid concentration with acute myocardial infarction and type 2 diabetes mellitus.
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Impact of diurnal temperature range on human health: a systematic review.
Int J Biometeorol
PUBLISHED: 01-23-2014
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Increasing epidemiological studies have shown that a rapid temperature change within 1 day is an independent risk factor for human health. This paper aimed to systematically review the epidemiological evidence on the relationship between diurnal temperature range (DTR) and human health and to propose future research directions. A literature search was conducted in October 2013 using the databases including PubMed, ScienceDirect, and EBSCO. Empirical studies regarding the relationship between DTR and mortality and morbidity were included. Twenty-five relevant studies were identified, among which, 11 investigated the relationship between DTR and mortality and 14 examined the impact of DTR on morbidity. The majority of existing studies reported that DTR was significantly associated with mortality and morbidity, particularly for cardiovascular and respiratory diseases. Notably, compared with adults, the elderly and children were more vulnerable to DTR effects. However, there were some inconsistencies regarding the susceptible groups, lag time, and threshold of DTR. The impact of DTR on human health may be confounded or modified by season, socioeconomic, and educational status. Further research is needed to further confirm the adverse effects of DTR in different geographical locations; examine the effects of DTR on the health of children aged one or under; explore extreme DTR effects on human health; analyze the difference of DTR effects on human health in different locations and the modified effects of potential confounding factors; and develop detailed preventive measures against large DTR, particularly for susceptible groups.
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Molecular analysis of the CYP21A2 gene in Chinese patients with steroid 21-hydroxylase deficiency.
Clin. Biochem.
PUBLISHED: 01-16-2014
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21-Hydroxylase deficiency (21-OHD) is the most common cause of congenital adrenal hyperplasia (CAH), a family of autosomal recessive disorders involving impaired cortisol synthesis. This study aimed to design a reliable and rational approach for identifying mutations in the CYP21A2 gene and to characterize the molecular basis of 21-OHD in 30 Chinese patients.
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MicroRNAs: New therapeutic targets for intestinal barrier dysfunction.
World J. Gastroenterol.
PUBLISHED: 01-14-2014
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Defects in intestinal barrier function characterized by an increase in intestinal permeability contribute to intestinal inflammation. Growing evidence has shown that an increase in intestinal permeability has a pathogenic role in diseases such as inflammatory bowel disease (IBD) and celiac disease, and functional bowel disorders such as irritable bowel syndrome. Therefore, clarification of the inflammatory responses, the defense pathway and the corresponding regulatory system is essential and may lead to the development of new therapies. MicroRNAs (miRNAs) are small (19-22 nt) noncoding RNA molecules that regulate genes at the post-transcriptional level by base-pairing to specific messenger RNAs for degradation to repress translation. Recent studies suggested that miRNAs are important in the immune response and mediate a critical role in multiple immune response-related disorders. Based on these discoveries, attention has been focused on understanding the role of miRNAs in regulating intestinal barrier dysfunction, especially in IBD. Here, we provide a review of the most recent state-of-the-art research on miRNAs in intestinal barrier dysfunction.
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Synergistic inhibition of breast cancer by co-delivery of VEGF siRNA and paclitaxel via vapreotide-modified core-shell nanoparticles.
Biomaterials
PUBLISHED: 01-13-2014
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A somatostatin analog, vapreotide (VAP), can be used as a ligand for targeting drug delivery based on its high affinity to somatostatin receptors (SSTRs), which is overexpressed in many tumor cells. RNA interference plays an important role on downregulation of vascular endothelial growth factor (VEGF), which is important for tumor growth, progression and metastasis. To improve tumor therapy efficacy, the vapreotide-modified core-shell type nanoparticles co-encapsulating VEGF targeted siRNA (siVEGF) and paclitaxel (PTX), termed as VAP-PLPC/siRNA NPs, were developed in this study. When targeted via somatostatin receptors to tumor cells, the VAP-PLPC/siRNA NPs could simultaneously delivery siVEGF and PTX into cells and achieve a synergistic inhibition of tumor growth. Interestingly, in vitro cell uptake and gene silencing experiments demonstrated that the targeted VAP-PLPC/siRNA NPs exhibited significant higher intracellular siRNA accumulation and VEGF downregulation in human breast cancer MCF-7 cells, compared to those of the non-targeted PEG-PLPC/siRNA NPs. More importantly, in vivo results further demonstrated that the targeted VAP-PLPC/siRNA NPs had significant stronger drug distribution in tumor tissues and tumor growth inhibition efficacy via receptor-mediated targeting delivery, accompany with an obvious inhibition of neovascularization induced by siVEGF silencing. These results suggested that the co-delivery of siRNA and paclitaxel via vapreotide-modified core-shell nanoparticles would be a promising approach for tumor targeted therapy.
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Sirtuin 1 facilitates chemoresistance of pancreatic cancer cells by regulating adaptive response to chemotherapy-induced stress.
Cancer Sci.
PUBLISHED: 01-07-2014
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Chemotherapy drugs themselves may act as stressors to induce adaptive responses to promote the chemoresistance of cancer cells. Our previous research showed that sirtuin 1 (SIRT1) was overexpressed in pancreatic cancer patients and deregulation of SIRT1 with RNAi could enhance chemosensitivity. Thus, we hypothesized that SIRT1 might facilitate chemoresistance in pancreatic cancer cells through regulating the adaptive response to chemotherapy-induced stress. In the present study, SIRT1 in PANC-1, BXPC-3, and ASPC-1 cells was upregulated after treatment with gemcitabine. Moreover, the decrease in SIRT1 activity with special inhibitor EX527 had a synergic effect on chemotherapy with gemcitabine in PANC-1 and ASPC-1 cell lines, which significantly promoted apoptosis, senescence, and G0 /G1 cycle arrest. Western blot results also showed that SIRT1, acetylated-p53, FOXO3a, and p21 were upregulated after combined treatment, whereas no obvious change was evident in total p53 protein. To further confirm the role of SIRT1 in clinical chemotherapy, SIRT1 was detected in eight pancreatic cancer tissues acquired by endoscopy ultrasonography guided fine needle aspiration biopsy before and after chemotherapy. Compared to before chemotherapy, SIRT1 was significantly increased after treatment with gemcitabine in six cases. Thus, our results indicated a special role for SIRT1 in the regulation of adaptive response to chemotherapy-induced stress, which is involved in chemoresistance. Moreover, it indicates that blocking SIRT1 activity with targeting drugs might be a novel strategy to reverse the chemoresistance of pancreatic cancer.
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Theranostic nanoparticles based on bioreducible polyethylenimine-coated iron oxide for reduction-responsive gene delivery and magnetic resonance imaging.
Int J Nanomedicine
PUBLISHED: 01-01-2014
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Theranostic nanoparticles based on superparamagnetic iron oxide (SPIO) have a great promise for tumor diagnosis and gene therapy. However, the availability of theranostic nanoparticles with efficient gene transfection and minimal toxicity remains a big challenge. In this study, we construct an intelligent SPIO-based nanoparticle comprising a SPIO inner core and a disulfide-containing polyethylenimine (SSPEI) outer layer, which is referred to as a SSPEI-SPIO nanoparticle, for redox-triggered gene release in response to an intracellular reducing environment. We reveal that SSPEI-SPIO nanoparticles are capable of binding genes to form nano-complexes and mediating a facilitated gene release in the presence of dithiothreitol (5-20 mM), thereby leading to high transfection efficiency against different cancer cells. The SSPEI-SPIO nanoparticles are also able to deliver small interfering RNA (siRNA) for the silencing of human telomerase reverse transcriptase genes in HepG2 cells, causing their apoptosis and growth inhibition. Further, the nanoparticles are applicable as T2-negative contrast agents for magnetic resonance (MR) imaging of a tumor xenografted in a nude mouse. Importantly, SSPEI-SPIO nanoparticles have relatively low cytotoxicity in vitro at a high concentration of 100 ?g/mL. The results of this study demonstrate the utility of a disulfide-containing cationic polymer-decorated SPIO nanoparticle as highly potent and low-toxic theranostic nano-system for specific nucleic acid delivery inside cancer cells.
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Clinical outcomes of transfusion-associated iron overload in patients with refractory chronic anemia.
Patient Prefer Adherence
PUBLISHED: 01-01-2014
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The purpose of this study was to evaluate the clinical outcomes of transfusion-associated iron overload in patients with chronic refractory anemia.
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Training set selection for the prediction of essential genes.
PLoS ONE
PUBLISHED: 01-01-2014
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Various computational models have been developed to transfer annotations of gene essentiality between organisms. However, despite the increasing number of microorganisms with well-characterized sets of essential genes, selection of appropriate training sets for predicting the essential genes of poorly-studied or newly sequenced organisms remains challenging. In this study, a machine learning approach was applied reciprocally to predict the essential genes in 21 microorganisms. Results showed that training set selection greatly influenced predictive accuracy. We determined four criteria for training set selection: (1) essential genes in the selected training set should be reliable; (2) the growth conditions in which essential genes are defined should be consistent in training and prediction sets; (3) species used as training set should be closely related to the target organism; and (4) organisms used as training and prediction sets should exhibit similar phenotypes or lifestyles. We then analyzed the performance of an incomplete training set and an integrated training set with multiple organisms. We found that the size of the training set should be at least 10% of the total genes to yield accurate predictions. Additionally, the integrated training sets exhibited remarkable increase in stability and accuracy compared with single sets. Finally, we compared the performance of the integrated training sets with the four criteria and with random selection. The results revealed that a rational selection of training sets based on our criteria yields better performance than random selection. Thus, our results provide empirical guidance on training set selection for the identification of essential genes on a genome-wide scale.
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The assessment of the quality of reporting of systematic reviews/meta-analyses in diagnostic tests published by authors in China.
PLoS ONE
PUBLISHED: 01-01-2014
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The quality of reporting in systematic reviews (SRs)/meta-analyses (MAs) of diagnostic tests published by authors in China has not been evaluated. The aims of present study are to evaluate the quality of reporting in diagnostic SRs/MAs using the PRISMA statement and determine the changes in the quality of reporting over time.
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Efficacy and Safety of Accelerated Partial Breast Irradiation after Breast-conserving Surgery: A Meta-analysis of Published Comparative Studies.
Breast J
PUBLISHED: 12-26-2013
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To compare the treatment outcomes between accelerated partial breast irradiation (APBI) and conventional whole-breast irradiation (WBI) and to explore the efficacy and safety of APBI as an adjuvant treatment for early-stage breast cancer who received breast-conserving therapy. Eligible studies were identified on Medline, Embase, and the Cochrane Library updated to July 10, 2012. Comparative studies were considered for inclusion. Analyses were carried out using Stata software. Eleven comparative studies with a total of 7,097 patients were included. The meta-analysis showed that there were no statistically significant differences between group APBI and group WBI associated with the supraclavicular failure, distant metastasis, overall survival, and disease-free survival, while local recurrence (LR) and axillary failure (AF) increased in group APBI. The sensitivity analysis indicated that both the LR and AF were not statistically significant difference between the two groups. In the subgroup analysis, LR was statistically significantly higher in group APBI for patients with the age <60, large tumor size, and unknown margin status. APBI is a safe treatment modality and could become a potential option for the delivery of adjuvant radiation therapy in patients receiving breast-conserving therapy, especially for the suitable group that was classified by the American Society of Radiation Oncology Consensus Panel.
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AOPPs Induce MCP-1 Expression by Increasing ROS-Mediated Activation of the NF-?B Pathway in Rat Mesangial Cells: Inhibition by Sesquiterpene Lactones.
Cell. Physiol. Biochem.
PUBLISHED: 11-26-2013
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Background: Monocyte chemoattractant protein-1 (MCP-1) plays an important role in extracellular matrix accumulation through macrophage recruitment and activation in the development and progression of diabetic nephropathy. Therefore, this study examined whether advanced oxidation protein products (AOPPs) are involved in nuclear factor-?B (NF-?B) activation and MCP-1 mRNA and protein expression in mesangial cells (MCs) and evaluated the effects of derivatives of sesquiterpene lactones (SLs) on AOPP-induced renal damage. Methods: MCP-1 mRNA and protein expression in MCs were determined by quantitative real-time PCR and ELISA, respectively. The level of intracellular reactive oxygen species (ROS) was determined by flow cytometry. The protein expression of tubulin, P47, NF-?B p65, phospho-NF-?B p65, I?B, phospho-I?B, IKK? and phospho-IKK? was evaluated by Western blot. Results: AOPPs caused oxidative stress in MCs and activated the NF-?B pathway by inducing I?B? phosphorylation and degradation. Inhibition of ROS by SOD (ROS inhibitor) blocked the AOPP-mediated NF-?B pathway. Moreover, the inhibition of AOPP-induced overproduction of MCP-1 mRNA and protein was associated with inhibition of I?B? degradation by SLs. Conclusion: AOPPs induce MCP-1 expression by activating the ROS/NF-?B pathway and can be inhibited by SLs. These findings may provide a novel approach to treat inflammatory and immune renal diseases, including diabetic nephropathy. © 2014 S. Karger AG, Basel.
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Core-Shell type lipid/rPAA-Chol polymer hybrid nanoparticles for in vivo siRNA delivery.
Biomaterials
PUBLISHED: 10-24-2013
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Our previous study had reported that cholesterol-grafted poly(amidoamine) (rPAA-Chol polymer) was able to self-assemble into cationic nanoparticles and act as a potential carrier for siRNA transfection. In this study, the core-shell type lipid/rPAA-Chol hybrid nanoparticles (PEG-LP/siRNA NPs and T7-LP/siRNA NPs) were developed for improving in vivo siRNA delivery by modifying the surface of rPAA-Chol/siRNA nanoplex core with a lipid shell, followed by post-insertion of polyethylene glycol phospholipid (DSPE-PEG) and/or peptide (HAIYPRH, named as T7) modified DSPE-PEG-T7. The integrative hybrid nanostructures of LP/siRNA NPs were evidenced by dynamic light scattering (DLS), confocal laser scanning microscope (CLSM), cryo-transmission electron microscope (Cryo-TEM) and surface plasmon resonance (SPR) assay. It was demonstrated that the T7 peptide modified LP/siRNA NPs (T7-LP/siRNA NPs) exhibited uniform and spherical structures with particle size of 99.39 ± 0.65 nm and surface potential of 42.53 ± 1.03 mV, and showed high cellular uptake efficiency and rapid endosomal/lysosomal escape ability in MCF-7 cells. Importantly, in vitro gene silencing experiment demonstrated that both of pegylated and targeted LP/siEGFR NPs exhibited significantly stronger downregulation of EGFR protein expression level in MCF-7 cells, compared to that of the physical mixture of siRNA lipoplexes and rPAA-Chol/siRNA nanoplexes. In vivo tumor therapy on nude mice bearing MCF-7 tumors further confirmed that the targeted T7-LP/siEGFR NPs exhibited the greatest inhibition on tumor growth via transferrin receptor-mediated targeting delivery, without any activation of immune responses and significant body weight loss following systemic administration. These findings indicated that the core-shell type T7-LP/siRNA nanoparticles would be promising siRNA delivery systems for in vivo tumor-targeted therapy.
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Object detection via structural feature selection and shape model.
IEEE Trans Image Process
PUBLISHED: 09-18-2013
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In this paper, we propose an approach for object detection via structural feature selection and part-based shape model. It automatically learns a shape model from cluttered training images without need to explicitly use bounding boxes on objects. Our approach first builds a class-specific codebook of local contour features, and then generates structural feature descriptors by combining context shape information. These descriptors are robust to both within-class variations and scale changes. Through exploring pairwise image matching using fast earth movers distance, feature weights can be iteratively updated. Those discriminative foreground features are assigned high weights and then selected to build a part-based shape model. Finally, object detection is performed by matching each testing image with this model. Experiments show that the proposed method is very effective. It has achieved comparable performance to the state-of-the-art shape-based detection methods, but requires much less training information.
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Sesquiterpene lactones and their derivatives inhibit high glucose-induced NF-?B activation and MCP-1 and TGF-?1 expression in rat mesangial cells.
Molecules
PUBLISHED: 09-12-2013
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Diabetic nephropathy (DN) is one of the most common and serious chronic complications of diabetes mellitus, however, no efficient clinical drugs exist for the treatment of DN. We selected and synthesized several sesquiterpene lactones (SLs), and then used the MTT assay to detect rat mesangial cells (MCs) proliferation, ELISA to measure the expression level of monocyte chemoattractant protein-1 (MCP-1), transforming growth factor beta (TGF-?1) and fibronectin(FN), real-time fluorescent quantitative PCR analysis to measure the MCP-1 and TGF-?1 gene expression, western blot to detect the level of I?B? protein and EMSA to measure the activation of nuclear factor kappa B (NF-?B). We discovered that SLs, including parthenolide (PTL), micheliolide (MCL), arglabin, and isoalantolactone (IAL), as well as several synthetic analogs of these molecules, could effectively attenuate the high glucose-stimulated activation of NF-?B, the degradation of I?B?, and the expression of MCP-1, TGF-?1 and FN in rat mesangial cells (MCs). These findings suggest that SLs and their derivatives have potential as candidate drugs for the treatment of DN.
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[Clinical application of BCR/ABL probes in myeloproliferative disorders].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 09-04-2013
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This study was purposed to explore the application value of fluorescence in situ hybridization (FISH) detection in differential diagnosis of chronic myeloproliferative disorders (CMPD) and Ph(+) acute lymphoblastic leukemia (Ph(+) ALL), as well as in dynamic monitoring of minimal residual disease (MRD) after treatment. The BCR/ABL fusion gene of newly diagnosed and treated cases was detected by using BCR/ABL (ES) probe and BCR/ABL (DF) probe respectively. The results showed that among 49 newly diagnosed cases considered as CMPD, 28 cases met the criterion of CML morphologically, out of them 23 cases were eventually diagnosed to be CML and with morphological consistent rate 82.1% (23/28), the sensitivity and specificity all were 100% (23/23). The BCR/ABL positive rate of eventually diagnosed cases was 81.3% ± 17.7%. Among 13 cases received allogeneic haemopoietic stem cell transplantation (allo-HSCT), 9 cases achieved long-term disease-free survival and 4 cases relapsed, the several monitoring for whom after donor lymphocyte infusion (DLI) and imatinib treatment or allo-HSCT showed BCR/ABL negative. Among 16 cases treated with imatinib, 11 cases remained BCR/ABL negative after 1 year; 5 cases showed BCR/ABL positive during 6, 7 and 10 years after treatment, respectively, but out of them BCR/ABL positive in 1 case turned negative after allo-HSCT. It is concluded that the FISH is sensitive and specific diagnostic technique, the detection of BCR/ABL fusion gene in newly diagnosed and treated cases by using 2 different probes can help to fast and accurately determine the differential diagnosis for CML and Ph(+) ALL, and dynamically monitor the MRD after treatment with imatinib and allo-HSCT.
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An unusual seven-connected lead borate constructed by different cluster building units of {B6} and {Pb6}.
Dalton Trans
PUBLISHED: 08-28-2013
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A new 3D lead borate Pb(6)B(6)O(14)(OH)(2)(H(2)O), built by different cluster building units of B(6)O(14)(OH) {B(6)} and Pb(6)O(5)(OH) {Pb(6)}, has been obtained under mild hydrothermal conditions. Each {B(6)} cluster is linked with seven {Pb(6)} clusters and vice versa that give rise to the first 7-connected lead borate network.
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Fabrication of spherical mitigation pit on KH2PO4 crystal by micro-milling and modeling of its induced light intensification.
Opt Express
PUBLISHED: 08-14-2013
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Micro-machining is the most promising method for KH(2)PO(4) crystal to mitigate the surface damage growth in high power laser system. In this work, spherical mitigation pit is fabricated by micro-milling with an efficient machining procedure. The light intensification caused by rear surface features before and after mitigation is numerically modeled based on the finite-difference time-domain method. The results indicate that the occurrence of total internal reflections should be responsible for the largest light intensification inside the crystal. For spherical pits after mitigation, the light intensification can be greatly alleviated by preventing the occurrence of total internal reflections. The light intensification caused by spherical mitigation pit is strongly dependent on the width-depth ratio and it is suggested that the width-depth ratio of spherical mitigation pit must be devised to be larger than 5.0 to achieve the minimal light intensification for the mitigation of surface damage growth. Laser damage tests for KH(2)PO(4) crystal validate that the laser damage resistance of initially damaged surface can be retrieved to near the level of ideal surface by replacing initial damage site with predesigned mitigation pit.
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Explore the radiotherapeutic clinical target volume delineation for thoracic esophageal squamous cell carcinoma from the pattern of lymphatic metastases.
J Thorac Oncol
PUBLISHED: 07-31-2013
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Esophageal carcinoma is characterized by a high frequency of lymph node metastasis (LNM). It is difficult to accurately define the radiotherapeutic clinical target volume in patients with thoracic esophageal squamous cell carcinoma (ESCC), because the LNM rate and the included node level varied greatly among previous studies. This study aimed to determine which node level should be included for radiotherapy by analyzing LNM rate in thoracic ESCC patients.
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Role of cyclooxygenase-2 in gastric cancer development and progression.
World J. Gastroenterol.
PUBLISHED: 07-21-2013
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Although the incidence of gastric cancer has been declining in recent decades, it remains a major public health issue as the second leading cause of cancer death worldwide. In China, gastric cancer is still the main cause of death in patients with malignant tumors. Most patients are diagnosed at an advanced stage and mortality is high. Cyclooxygenase-2 (COX-2) is a rate-limiting enzyme in prostanoid synthesis and plays an important role in the development and progression of gastric cancer. The expression of COX-2 in gastric cancer is upregulated and its molecular mechanisms have been investigated. Helicobacter pylori infection, tumor suppressor gene mutation and the activation of nuclear factor-kappa B may be responsible for the elevated expression of COX-2 in gastric cancer. The mechanisms of COX-2 in the development and progression of gastric cancer are probably through promoting the proliferation of gastric cancer cells, while inhibiting apoptosis, assisting angiogenesis and lymphatic metastasis, and participating in cancer invasion and immunosuppression. This review is intended to discuss, comment and summarize recent research progress on the role of COX-2 in gastric cancer development and progression, and elucidate the molecular mechanisms which might be involved in the carcinogenesis.
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Effects of Androgens on Early Post-ischemic Neurogenesis in Mice.
Transl Stroke Res
PUBLISHED: 07-17-2013
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Although androgens are reported to affect stroke outcomes by altering ischemic tissue damage, their effect on post-injury repair is unknown. Since neurogenesis has recently been recognized as contributing to stroke outcomes, we investigated the role of androgens on stroke-induced neurogenesis. Adult male mice were subjected to transient middle cerebral artery occlusion (MCAO) and neurogenesis was examined 1 week later by quantifying BrdU/doublecortin-positive and BrdU/NeuN-positive neurons in brain germinal regions as well as the injured striatum. To elucidate the role of endogenous androgens, post-MCAO neurogenesis was examined in gonadally intact males, intact males implanted with the androgen receptor antagonist flutamide, and surgically castrated males. Surgical castration or pharmacologic androgen receptor blockade had no effects on post-ischemic neurogenesis, except that continuous androgen receptor blockade unexpectedly suppressed maturation of newborn neurons (BrdU/NeuN-positive cells) in the dentate gyrus. Post-MCAO neurogenesis was also examined in surgically castrated mice treated with continuous release implants containing testosterone or dihydrotestosterone (DHT). Testosterone and DHT robustly inhibited post-ischemic neurogenesis in the dentate gyrus, and the more potent androgen DHT virtually abolished the presence of immature newborn neurons (BrdU/doublecortin-positive cells) in the injured striatum. Our data suggest that endogenous androgens do not alter post-stroke neurogenesis quantitatively, but the presence of supra-physiological androgen stimulation profoundly suppresses early neurogenesis in germinal brain areas and reduces cellular repair in injured tissue after cerebral ischemia. These results advance the understanding of the role that androgens play in stroke outcomes.
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The roles of two transcription factors, ABI4 and CBFA, in ABA and plastid signalling and stress responses.
Plant Mol. Biol.
PUBLISHED: 06-27-2013
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Genetic and physiological studies have revealed evidences for multiple signaling pathways by which the plastid exerts retrograde control over photosynthesis-associated-nuclear-genes. In this study we have examined the mechanisms of control of transcription by plastid signals, focusing on transcription factors. We have also further addressed the physical nature of plastid signals and the physiological role, in stress acclimation of this regulatory pathway. ABI4, a master Apetala 2 (AP2)-type transcription factor (TF), is targeted by multiple signalling pathways in plant cells, such as abscisic acid (ABA) signals, sugar signals and plastid signals derived from reactive oxygen species (ROS) and chlorophyll intermediates. ABI4 binds the promoter of target genes to prevent their transcription by competing with other competitive TFs. However, we found that once ABI4 bound the element (CCACGT), it may not be bound by other TFs, therefore making the signalling long-lasting. Downstream of ABI4, CBFA (CCAAT binding factor A) is a subunit of the HAP2/HAP3/HAP5 (Heme activator protein) trimeric transcription complex. CBFA however is a redundant HAP3 subunit. When emergency occurs (such as herbicide treatments or environmental stresses followed by ABA and ROS accumulation), the master transcription factor ABI4 down-regulates some TFs, like CBFA, and then some other TF subunits enter the transcription complex and transcriptional efficiency of stress-responsive genes (including the transcription co-factor CBP) is improved instantaneously. abi4, cbfA and cbp mutants showed weaker drought-tolerance after a herbicide norflurazon treatment, which indicated the physiological role of these key transcription factors.
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Maternal coffee consumption during pregnancy and risk of childhood acute leukemia: a metaanalysis.
Am. J. Obstet. Gynecol.
PUBLISHED: 06-22-2013
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This study was undertaken to explore the association between maternal coffee consumption during pregnancy and childhood acute leukemia (AL).
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Luminescent 2D bismuth-cadmium-organic frameworks with tunable and white light emission by doping different lanthanide ions.
Dalton Trans
PUBLISHED: 06-18-2013
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The first luminescent Bi-Cd-organic framework, Bi2Cd(2,6-pdc)4(H2O)2·H2O (2,6-H2pdc = pyridine-2,6-dicarboxylate), has been synthesized by using bismuth (Bi) oxides and cadmium (Cd) salts as metal sources under hydrothermal conditions. Tunable and white light luminescence was obtained through the doping of different Ln(3+) ions into the Bi-Cd-organic framework.
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A new computational strategy for predicting essential genes.
BMC Genomics
PUBLISHED: 06-15-2013
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Determination of the minimum gene set for cellular life is one of the central goals in biology. Genome-wide essential gene identification has progressed rapidly in certain bacterial species; however, it remains difficult to achieve in most eukaryotic species. Several computational models have recently been developed to integrate gene features and used as alternatives to transfer gene essentiality annotations between organisms.
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Two important mechanisms damaging KH2PO4 crystal processed by ultraprecision fly cutting and their relationships with cutting parameters.
Appl Opt
PUBLISHED: 06-06-2013
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Mid-frequency waviness and subsurface crack are two fundamental factors that damage KH(2)PO(4) (KDP) crystal processed by ultraprecise fly cutting. In this paper, the motif theory and the Fourier model method are used to analyze the influence of the two factors on the laser-induced damage threshold (LIDT) of KDP. Research results indicate that the modulation degrees increase nearly linearly when the waviness amplitude and subsurface crack depth increase, and, meanwhile, the LIDT tends to decrease. The two factors have different effects during different stages of KDP failure. The mean amplitudes of waviness and subsurface damage depth have similar changing regulations with different feeds. From the machining perspective, we need not necessarily know which is more dangerous, because when one factor is controlled, the other one will also be restrained at the same time. In general, smaller feed and cutting depth are benefits for improving the LIDT of KDP.
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Facile assembly of an unusual lead borate with different cluster building units via a hydrothermal process.
Inorg Chem
PUBLISHED: 05-10-2013
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Pb(BO2)2·H2O as sources of B and Pb via a simple hydrothermal process provided the first binodal 5,9-connected lead borate, Pb6B4O11(OH)2 (1). Compound 1 crystallizes in the orthorhombic space group Pnma. The crystal structure is composed of different cluster building units of B4O9 and Pb6O4. Compound 1 has an optical band gap of 3.24 eV.
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Association between PAI-1 4G/5G Polymorphisms and osteonecrosis of femoral head: a meta-analysis.
Thromb. Res.
PUBLISHED: 05-06-2013
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The polymorphism of the plasminogen activator inhibitor-1 (PAI-1) 4 G/5 G gene has been correlated with susceptibility to osteonecrosis of the femoral head (ONFH), but study results are controversial. The aim of this study was to derive a more precise estimation of the relationship between the PAI-1 4 G/5 G Gene polymorphism and ONFH by performing a meta-analysis.
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Enhancement of adenosine production by Bacillus subtilis CGMCC 4484 through metabolic flux analysis and simplified feeding strategies.
Bioprocess Biosyst Eng
PUBLISHED: 04-14-2013
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The objective of this research was to understand how the initial glucose concentration influences adenosine (AR) production and metabolic flux shift on the cultivation of Bacillus subtilis CGMCC 4484. Experiments confirmed that initial glucose concentration affects cell growth, AR production and metabolites, significantly. The flux distribution at the key nodes of glucose-6-phosphate (G6P), pyruvate (PYR) and acetyl coenzyme-A (AcCoA) could be affected by changing the glucose concentration. Based on kinetic analysis of specific rates, the low-glucose concentration was better for both cell growth and AR production during the first 12 h. However, the high-glucose concentration was more favorable for AR formation after 18 h. Furthermore, different simplified feeding strategies were designed to achieve higher AR accumulation. The final AR concentration of 15.60 g L(-1) was achieved when an optimized constant-feeding strategy was used, which was 21.02 % higher than batch fermentation. This was the first time to investigate the regulation of the glucose metabolism of AR-producing B. subtilis.
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Incorporating different secondary building units of {Bi2}, {Bi8} and {Bi10} to construct diversity of luminescent bismuth-organic frameworks.
Dalton Trans
PUBLISHED: 04-05-2013
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Three new bismuth-organic compounds, namely, Bi(OH)(2,6-pdc)·H(2)O (1), Bi(4)(OH)(4)(2,6-pdc)(4)(H(2)O)(3)·H(2)O (2) and Bi(5)(OH)(5)(2,6-pdc)(5)(H(2)O)(4)·H(2)O (3) (2,6-H(2)pdc = pyridine-2,6-dicarboxylate) have been obtained by incorporating different Bi subunits as building blocks under hydrothermal conditions. Compound 1 contains dimeric {Bi(2)} units and these are further linked by 2,6-pdc(2-) ligands into a 2D net with 3(6) topology. Compounds 2-3 display 4(4) net topology by using linear {Bi(8)} and {Bi(10)} as secondary building units (SBUs), respectively. Compounds 1-3 display yellow and blue luminescence, respectively. Furthermore, the PXRD, TGA, UV-visible and IR spectra of 1-3 were also studied.
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Community composition and cellulase activity of cellulolytic bacteria from forest soils planted with broad-leaved deciduous and evergreen trees.
Appl. Microbiol. Biotechnol.
PUBLISHED: 03-09-2013
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Cellulolytic bacteria in forest soil provide carbon sources to improve the soil fertility and sustain the nutrient balance of the forest ecological system through the decomposition of cellulosic remains. These bacteria can also be utilized for the biological conversion of biomass into renewable biofuels. In this study, the community compositions and activities of cellulolytic bacteria in the soils of forests planted with broad-leaved deciduous (Chang Qing Garden, CQG) and broad-leaved evergreen (Forest Park, FP) trees in Wuhan, China were resolved through restriction fragment length polymorphism (RFLP) and sequencing analysis of the 16S rRNA gene. All of the isolates exhibited 35 RFLP fingerprint patterns and were clustered into six groups at a similarity level of 50 %. The phylogeny analysis based on the 16S rRNA gene sequence revealed that these RFLP groups could be clustered into three phylogenetic groups and further divided into six subgroups at a higher resolution. Group I consists of isolates from Bacillus cereus, Bacillus subtilis complex (I-A) and from Paenibacillus amylolyticus-related complex (I-B) and exhibited the highest cellulase activity among all of the cellulolytic bacteria isolates. Cluster II consists of isolates belonging to Microbacterium testaceum (II-A), Chryseobacterium indoltheticum (II-B), and Flavobacterium pectinovorum and the related complex (II-C). Cluster III consists of isolates belonging to Pseudomonas putida-related species. The community shift with respect to the plant species and the soil properties was evidenced by the phylogenetic composition of the communities. Groups I-A and I-B, which account for 36.0 % of the cellulolytic communities in the CQG site, are the dominant groups (88.4 %) in the FP site. Alternatively, the ratio of the bacteria belonging to group III (P. putida-related isolates) shifted from 28.0 % in CQG to 4.0 % in FP. The soil nutrient analysis revealed that the CQG site planted with deciduous broad-leaved trees has a richer organic nutrient (total organic carbon and total nitrogen) than the FP site planted with evergreen broad-leaved trees. Against this background, the population density and the diversity of cellulolytic bacteria in the CQG site are clearly higher than those in the FP site, and the latter was dominated with high-cellulase-activity Bacillus- and Paenibacillus-related bacteria. The canonical correspondence analysis further indicated that the distribution of these groups is correlated with the FP site, whereas groups II and III are correlated with the organic nutrient-rich CQG site.
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[Development and application of a method for molecular diagnosis of 21-hydroxylase deficiency].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 03-02-2013
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To develop a method for elucidating genetic basis of 21-hydroxylase deficiency.
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Handy, rapid and multiplex detection of tumor markers based on encoded silica-hydrogel hybrid beads array chip.
Biosens Bioelectron
PUBLISHED: 02-25-2013
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Malignant tumor has become the leading cause of death worldwide; however, multiplex detection technology could provide great assistance in large-scale population screening of diseases which could effectively reduce the mortality of malignant tumors. Here a microbeads array chip, which could be a perfect alternative method for the early screening, was developed. Silica-hydrogel hybrid bead (SHHB) with photonic encoding, which consists of both silica and hydrogel materials, was manufactured as the carrier of microbeads array for the first time. The SHHB has the advantages of the beads made of silica or hydrogel, but does not have their limitations. Reaction conditions of SHHBs array were optimized and then the fluorescent concentration curves of two widely-used tumor markers, human alpha fetoprotein and carcinoembryonic antigen, were constructed. The accuracy of SHHBs array has been proven according to the comparison between the results obtained by detecting 50 clinical samples with SHHBs array and chemiluminescence immunoassay. A cassette like chip device has also been developed to standardize operational processes and benefit automization in the next work. Hence it is concluded that SHHBs array chip is a handy, rapid and multiplex immunoassay technology, which could imply its practical application in clinical immunoassay in the near future.
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Effect of the scale of quantitative trait data on the representativeness of a cotton germplasm sub-core collection.
J Zhejiang Univ Sci B
PUBLISHED: 02-01-2013
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A cotton germplasm collection with data for 20 quantitative traits was used to investigate the effect of the scale of quantitative trait data on the representativeness of plant sub-core collections. The relationship between the representativeness of a sub-core collection and two influencing factors, the number of traits and the sampling percentage, was studied. A mixed linear model approach was used to eliminate environmental errors and predict genotypic values of accessions. Sub-core collections were constructed using a least distance stepwise sampling (LDSS) method combining standardized Euclidean distance and an unweighted pair-group method with arithmetic means (UPGMA) cluster method. The mean difference percentage (MD), variance difference percentage (VD), coincidence rate of range (CR), and variable rate of coefficient of variation (VR) served as evaluation parameters. Monte Carlo simulation was conducted to study the relationship among the number of traits, the sampling percentage, and the four evaluation parameters. The results showed that the representativeness of a sub-core collection was affected greatly by the number of traits and the sampling percentage, and that these two influencing factors were closely connected. Increasing the number of traits improved the representativeness of a sub-core collection when the data of genotypic values were used. The change in the genetic diversity of sub-core collections with different sampling percentages showed a linear tendency when the number of traits was small, and a logarithmic tendency when the number of traits was large. However, the change in the genetic diversity of sub-core collections with different numbers of traits always showed a strong logarithmic tendency when the sampling percentage was changing. A CR threshold method based on Monte Carlo simulation is proposed to determine the rational number of traits for a relevant sampling percentage of a sub-core collection.
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Self-assembly cationic nanoparticles based on cholesterol-grafted bioreducible poly(amidoamine) for siRNA delivery.
Biomaterials
PUBLISHED: 01-23-2013
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In this study, a series of bioreducible poly(amidoamine)s grafting different percentages of cholesterol (rPAA-Ch14: 14%, rPAA-Ch29: 29%, rPAA-Ch57: 57% and rPAA-Ch87: 87%) was synthesized and used for siRNA delivery. These amphiphilic polymers were able to self-assemble into cationic nanoparticles in aqueous solution at low concentrations. The nanoparticle formation was evidenced via cryo-transmission electron microscope (Cryo-TEM) and dynamic light scattering analysis. The average hydrodynamic size of rPAA-Ch blank nanoparticles was about 80-160 nm with zeta potential of 50-60 mV. Also, the effects of different percentages of cholesterol grafted onto rPAA on physicochemical characteristics, in vitro cytotoxicity, cellular uptake, VEGF gene silencing efficacy and translocation mechanism of rPAA-Ch/siRNA complexes were investigated. The results showed that rPAA-Ch57 polymer was not only able to form stable nanocomplexes and possess high cell uptake, but also to exhibit the best in vitro VEGF gene silencing efficacy and the best in vivo tumor growth inhibition effect when it was formulated with VEGF-siRNA. Moreover, the observations of confocal laser scanning microscope (CLSM) and the study of cholesterol competitive inhibition demonstrated that endosomal/lysosomal escape and cytoplasmic dissociation of rPAA-Ch57/siRNA complexes were dependent on the "proton sponge effect" and disulfide cleavage, following internalization with cholesterol-related endocytosis pathway and subsequent transportion into endosomes/lysosomes. These findings indicated that the rPAA-Ch57 polymer should be a promising and potent carrier for siRNA delivery.
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