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Find video protocols related to scientific articles indexed in Pubmed.
HSC capture and directional differentiation into vascular endothelial cells for metal stent coated chitosan/hyaluronic acid loading CD133 antibody.
Tissue Eng Part A
PUBLISHED: 11-19-2014
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A series of metal stents coated with chitosan/hyaluronic acid (CS/HA) loading antibodies by electrostatic self-assembled method were prepared, and the types of cells captured by antibodies and their differentiation in vascular endothelial cells evaluated by molecular biology and scanning electron microscope (SEM). The results showed that CD133-stent can selectively capture hemopoietic stem cells (HSC)which directionally differentiate into vascular endothelial cells in peripheral blood by (CS/HA) induction, and simultaneously inhibit migration and proliferation of immune cells and vascular smooth muscle cells. CD34-stent can capture HSC, hemopoietic progenitor cells (HPC) that differentiate into vascular endothelial cells and immune cells, promoting smooth muscle cells growth, leading to thrombosis, inflammation and rejection. CD133-stent by implanting into miniature pig heart coronary can repair vascular by capturing own HSC, thus contributing to the rapid natural vascular repair, avoiding inflammation and rejection, thrombotic and restenosis. These studies demonstrated that CD133-stent of HSC capture will be an ideal coated metal stent providing a new therapeutic approach for cardiovascular and cerebrovascular disease.
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Stromal TGF-? signaling induces AR activation in prostate cancer.
Oncotarget
PUBLISHED: 10-22-2014
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AR signaling is essential for the growth and survival of prostate cancer (PCa), including most of the lethal castration-resistant PCa (CRPC). We previously reported that TGF-? signaling in prostate stroma promotes prostate tumor angiogenesis and growth. By using a PCa/stroma co-culture model, here we show that stromal TGF-? signaling induces comprehensive morphology changes of PCa LNCaP cells. Furthermore, it induces AR activation in LNCaP cells in the absence of significant levels of androgen, as evidenced by induction of several AR target genes including PSA, TMPRSS2, and KLK4. SD-208, a TGF-? receptor 1 specific inhibitor, blocks this TGF-? induced biology. Importantly, stromal TGF-? signaling together with DHT induce robust activation of AR. MDV3100 effectively blocks DHT-induced, but not stromal TGF-? signaling induced AR activation in LNCaP cells, indicating that stromal TGF-? signaling induces both ligand-dependent and ligand-independent AR activation in PCa. TGF-? induces the expression of several growth factors and cytokines in prostate stromal cells, including IL-6, and BMP-6. Interestingly, BMP-6 and IL-6 together induces robust AR activation in these co-cultures, and neutralizing antibodies against BMP-6 and IL-6 attenuate this action. Altogether, our study strongly suggests tumor stromal microenvironment induced AR activation as a direct mechanism of CRPC.
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RUNX1 is essential for mesenchymal stem cell proliferation and myofibroblast differentiation.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 10-13-2014
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Myofibroblasts are a key cell type in wound repair, cardiovascular disease, and fibrosis and in the tumor-promoting microenvironment. The high accumulation of myofibroblasts in reactive stroma is predictive of the rate of cancer progression in many different tumors, yet the cell types of origin and the mechanisms that regulate proliferation and differentiation are unknown. We report here, for the first time to our knowledge, the characterization of normal human prostate-derived mesenchymal stem cells (MSCs) and the TGF-?1-regulated pathways that modulate MSC proliferation and myofibroblast differentiation. Human prostate MSCs combined with prostate cancer cells expressing TGF-?1 resulted in commitment to myofibroblasts. TGF-?1-regulated runt-related transcription factor 1 (RUNX1) was required for cell cycle progression and proliferation of progenitors. RUNX1 also inhibited, yet did not block, differentiation. Knockdown of RUNX1 in prostate or bone marrow-derived MSCs resulted in cell cycle arrest, attenuated proliferation, and constitutive differentiation to myofibroblasts. These data show that RUNX1 is a key transcription factor for MSC proliferation and cell fate commitment in myofibroblast differentiation. This work also shows that the normal human prostate gland contains tissue-derived MSCs that exhibit multilineage differentiation similar to bone marrow-derived MSCs. Targeting RUNX1 pathways may represent a therapeutic approach to affect myofibroblast proliferation and biology in multiple disease states.
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Cardiac Fiber Unfolding by Semidefinite Programming.
IEEE Trans Biomed Eng
PUBLISHED: 10-08-2014
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Diffusion-tensor imaging allows noninvasive assessment of the myocardial fiber architecture, which is fundamental in understanding the mechanics of the heart. In this context, tractography techniques are often used for representing and visualizing cardiac fibers, but their output is only qualitative. We introduce here a new framework towards a more quantitative description of the cardiac fiber architecture from tractography results. The proposed approach consists in taking threedimensional fiber tracts as inputs, and then unfolding these fibers in the Euclidean plane under local isometry constraints using semidefinite programming. The solution of the unfolding problem takes the form of a Gram matrix which defines the two-dimensional embedding of the fibers and whose spectrum provides quantitative information on their organization. Experiments on synthetic and real data show that unfolding makes it easier to observe and to study the cardiac fiber architecture. Our conclusion is that two-dimensional embedding of cardiac fibers is a promising approach to supplement three-dimensional rendering for understanding the functioning of the heart.
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PbS sensitized TiO2 nanotube arrays with different sizes and filling degrees for enhancing photoelectrochemical properties.
Phys Chem Chem Phys
PUBLISHED: 10-06-2014
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PbS nanoparticles (PbS NPs), an efficient sensitizer for TiO2 nanotube arrays (TiO2 NAs), were fabricated by the method of sonication-assisted successive ionic layer adsorption and reaction (SILAR). The filling degree and size of PbS NPs can be tuned by changing the repeated cycles (N) of the SILAR process. TiO2 NAs can be fully covered with PbS NPs with a size ranging from less than 4 nm to 25 nm and large aggregates inside and outside the nanotubes when N reaches 15. The growth mechanism of PbS NPs in TiO2 NAs was expounded in great detail in this work. Ultraviolet-visible diffuse-reflectance spectra and surface photovoltage spectroscopy were used to investigate the light absorption properties and the transfer behavior of photogenerated charges in PbS-modified TiO2 NA heterostructures. Results show that the absorption range of TiO2 NAs is extended from the ultraviolet to the visible region by PbS NPs modification. A heterojunction is formed between PbS NPs and TiO2 NAs, facilitating the separation of photogenerated charge carriers. This PbS NPs fully-covered TiO2 NA electrode exhibits the best photoelectrochemical performance in all PbS-sensitized TiO2 NA electrodes, due to a larger number of small PbS NPs (<4 nm). With AM 1.5G illumination at 100 mW cm(-2), its short-circuit current density, open-circuit voltage and photoelectric conversion efficiency are 9.55 mA cm(-2), 0.95 V and 2.83%, respectively.
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Free-Breathing Diffusion Tensor Imaging and Tractography of the Human Heart in Healthy Volunteers Using Wavelet-Based Image Fusion.
IEEE Trans Med Imaging
PUBLISHED: 09-13-2014
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Free-breathing cardiac diffusion tensor imaging (DTI) is a promising but challenging technique for the study of fiber structures of the human heart in vivo. This work proposes a clinically compatible and robust technique to provide three-dimensional (3D) fiber architecture properties of the human heart. To this end, ten short-axis slices were acquired across the entire heart using a multiple shifted trigger delay (TD) strategy under free breathing conditions. Interscan motion was first corrected automatically using a non-rigid registration method. Then, two post-processing schemes were optimized and compared: an algorithm based on principal component analysis (PCA) filtering and temporal maximum intensity projection (TMIP), and an algorithm that uses the wavelet-based image fusion (WIF) method. The two methods were applied to the registered diffusion-weighted (DW) images to cope with intrascan motion-induced signal loss. The tensor fields were finally calculated, from which fractional anisotropy (FA), mean diffusivity (MD), and 3D fiber tracts were derived and compared. The results show that the comparison of the FA values (FAPCATMIP=0.45±0.10, FAWIF=0.42±0.05, P=0.06) showed no significant difference, while the MD values (MDPCATMIP=0.83±0.12×10-3 mm2/s, MDWIF=0.74±0.05×10-3 mm2/s, P=0.028) were significantly different. Improved helix angle variations through the myocardium wall reflecting the rotation characteristic of cardiac fibers were observed with WIF. This study demonstrates that the combination of multiple shifted TD acquisitions and dedicated post-processing makes it feasible to retrieve in vivo cardiac tractographies from free-breathing DTI acquisitions. The substantial improvements were observed using the WIF method instead of the previously published PCATMIP technique.
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FOXP3+ lymphocyte density in pancreatic cancer correlates with lymph node metastasis.
PLoS ONE
PUBLISHED: 09-05-2014
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To determine if the density of FOXP3+ lymphocytes in primary tumors and lymph nodes in pancreatic cancer correlates with the presence of lymph node metastases.
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Synthesis, characterization, and bioactivity of carboxylic acid-functionalized titanium dioxide nanobelts.
Part Fibre Toxicol
PUBLISHED: 09-02-2014
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Surface modification strategies to reduce engineered nanomaterial (ENM) bioactivity have been used successfully in carbon nanotubes. This study examined the toxicity and inflammatory potential for two surface modifications (humic acid and carboxylation) on titanium nanobelts (TNB).
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Carnosic acid induces autophagic cell death through inhibition of the Akt/mTOR pathway in human hepatoma cells.
J Appl Toxicol
PUBLISHED: 09-01-2014
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The therapeutic goal of cancer treatment is now geared towards triggering tumour-selective cell death with autophagic cell death being required for the chemotherapy of apoptosis-resistant cancer. In this study, Carnosic acid (CA), a polyphenolic diterpene isolated from Rosemary (Rosemarinus officinalis), significantly induced autophagic cell death in HepG2 cells. Ca treatment caused the formation of autophagic vacuoles produced an increasing ratio of LC3-II to LC3-I in a time- and dose-dependent manner but had no effect on the levels of autophagy-related protein ATG6 and ATG13 expression. Autophagy inhibitors, 3-methyladenine (3-MA), chloroquine and bafilomycin A1, or ATG genes silencing in HepG2 cells significantly inhibited CA-induced autophagic cell death. The CA treatment decreased the levels of phosphorylated Akt and mTOR without any effects on PI3K or PTEN. Most importantly, overexpression of Akt and knockdown of PTEN attenuated autophagy induction in CA-treated cells. Taken together, our results indicated that CA induced autophagic cell death through inhibition of the Akt/mTOR pathway in human hepatoma cells. These findings suggest that CA has a great potential for the treatment of hepatoma via autophagic induction. Copyright © 2014 John Wiley & Sons, Ltd.
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Magnetic graphene-based nanotheranostic agent for dual-modality mapping guided photothermal therapy in regional lymph nodal metastasis of pancreatic cancer.
Biomaterials
PUBLISHED: 08-28-2014
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Although regional lymph nodes (RLN) dissection remains the only way to cure pancreatic cancer metastasis, it is unavoidably associated with sizable trauma, multiple complications, and low surgical resection rates. Thus, exploring a treatment approach for the ablation of drug-resistant pancreatic cancer is always of great concern. Moreover, reoperative and intraoperative mapping of RLN is also important during treatment, because only a few lymph nodes can be detected by the naked eye. In our study, graphene oxides modified with iron oxide nanoparticles (GO-IONP) as a nanotheranostic agent is firstly developed to diagnose and treat RLN metastasis of pancreatic cancer. The approach was designed based on clinical practice, the GO-IONP agent directly injected into the tumor was transported to RLN via lymphatic vessels. Compared to commercial carbon nanoparticles currently used in the clinic operation, the GO-IONP showed powerful ability of dual-modality mapping of regional lymphatic system by magnetic resonance imaging (MRI), as well as dark color of the agent providing valuable information that was instrumental for surgeon in making the preoperative plan before operation and intraoperatively distinguish RLN from surrounding tissue. Under the guidance of dual-modality mapping, we further demonstrated that metastatic lymph nodes including abdominal nodes could be effectively ablated by near-infrared (NIR) irradiation with an incision operation. The lower systematic toxicity of GO-IONP and satisfying safety of photothermal therapy (PTT) to neighbor tissues have also been clearly illustrated in our animal experiments. Using GO-IONP as a nanotheranostic agent presents an approach for mapping and photothermal ablation of RLN, the later may serve as an alternative to lymph node dissection by invasive surgery.
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Cation-pi interactions at non-redundant protein--RNA interfaces.
Biochemistry Mosc.
PUBLISHED: 08-11-2014
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Cation-pi interactions have proved to be important in proteins and protein-ligand complexes. Here, cation-pi interactions are analyzed for 282 non-redundant protein-RNA interfaces. The statistical results show that this kind of interactions exists in 65% of the interfaces. The four RNA bases are ranked as Gua>Ade>Ura>Cyt according to their propensity to participate in cation-pi interactions. The corresponding ranking for the involved amino acid residues is: Arg>Lys>Asn>Gln. The same trends are obtained based on the empirical energy calculation. The Arg-Gua pairs have the greatest stability and are also most frequently observed. The number of cation-pi pairs involving unpaired bases is 2.5 times as many as those involving paired bases. Hence, cation-pi interactions show sequence and structural specificities. For the bicyclic bases, Gua and Ade, their 5-atom rings participate in cation-pi interactions somewhat more than the 6-atom rings, with percentages of 54 and 46%, respectively, which is due to the higher cation-pi participation proportion (63%) of 5-atom rings in the paired bases. These results give a general view of cation-pi interactions at protein-RNA interfaces and are helpful in understanding the specific recognition between protein and RNA.
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An updated view on the differentiation of stem cells into endothelial cells.
Sci China Life Sci
PUBLISHED: 08-08-2014
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Endothelial cells form the internal barrier between circulating blood and the vessel wall. They regulate arterial activity and mediate pathological reactions to vascular injuries such as atherosclerosis and balloon angioplasty. The development and differentiation of endothelial cells is a complex and coordinated process involving multiple levels of signaling and transcriptional and post-transcriptional regulation. Elucidating the mechanism of endothelial differentiation will not only enhance our understanding of vascular disease pathogenesis, but also facilitate our ability to produce vessels cells from pluripotent stem cells for regeneration purposes. In this review, we discuss the current understanding of how stem cells differentiate into endothelial cells at the level of signaling, transcription and microRNA regulation.
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Design, synthesis and biological evaluation of novel 1-hydroxyl-3-aminoalkoxy xanthone derivatives as potent anticancer agents.
Eur J Med Chem
PUBLISHED: 07-22-2014
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A series of novel 1-hydroxyl-3-aminoalkoxy xanthone derivatives were designed, synthesized and evaluated for in vitro anticancer activity against four selected human cancer cell lines (nasopharyngeal neoplasm CNE, liver cancer BEL-7402, gastric cancer MGC-803, lung adenocarcinoma A549). Most of the synthesized compounds exhibit effective cytotoxic activity against the four tested cancer cell lines with the IC50 values at micromolar concentration level. Some preliminary structure-activity relationships were also discussed. In this series of derivatives, compound 3g shows excellent broad spectrum anticancer activity with IC50 values ranging from 3.57 to 20.07 ?M. The in vitro anticancer activity effect and action mechanism of compound 3g on human gastric carcinoma MGC-803 cell were further investigated. The results showed that compound 3g exhibits dose- and time-dependent anticancer effects on MGC-803 cells through apoptosis, which might be associated with its decreasing intracellular calcium and the mitochondrial membrane potential.
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Regulation of the P2X7R by microRNA-216b in human breast cancer.
Biochem. Biophys. Res. Commun.
PUBLISHED: 07-21-2014
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Breast cancer is the most common cancer in women around the world. However, the molecular mechanisms underlying breast cancer pathogenesis are only partially understood. Here, in this study, we found that P2X7R was up-regulated and miR-216b was down-regulated in breast cancer cell lines and tissues. Using bioinformatic analysis and 3'UTR luciferase reporter assay, we determined P2X7R can be directly targeted by miR-216b, which can down-regulate endogenous P2X7R mRNA and protein levels. Ectopic expression of miR-216b mimics leads to inhibited cell growth and apoptosis, while blocking expression of the miR-216b results in increased cell proliferation. Furthermore, our findings demonstrate that knockdown of P2X7R promotes apoptosis in breast cancer cells through down-regulating Bcl-2 and increasing the cleavage caspase-3 protein level. Finally, we confirmed that down-regulation of miR-216b in breast cancer is inversely associated with P2X7R expression level. Together, these findings establish miR-216b as a novel regulator of P2X7R and a potential therapeutic target for breast cancer.
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Modeling and optimization of multiple unmanned aerial vehicles system architecture alternatives.
ScientificWorldJournal
PUBLISHED: 07-20-2014
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Unmanned aerial vehicle (UAV) systems have already been used in civilian activities, although very limitedly. Confronted different types of tasks, multi UAVs usually need to be coordinated. This can be extracted as a multi UAVs system architecture problem. Based on the general system architecture problem, a specific description of the multi UAVs system architecture problem is presented. Then the corresponding optimization problem and an efficient genetic algorithm with a refined crossover operator (GA-RX) is proposed to accomplish the architecting process iteratively in the rest of this paper. The availability and effectiveness of overall method is validated using 2 simulations based on 2 different scenarios.
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Characterization of white spot syndrome virus VP52B and its interaction with VP26.
Virus Genes
PUBLISHED: 07-14-2014
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White spot syndrome virus (WSSV) is one of the major pathogens of cultured shrimp. Identification of envelope protein interactions has become a central issue for the understanding of WSSV assembly. In this paper, WSSV envelope protein VP52B was fused with GST-tag and expressed in Escherichia coli BL-21(DE3). Immunogold-electron microscopy revealed that VP52B was located on the outside surface of WSSV virions. Far-Western blotting analysis suggested that VP52B might directly interact with a major viral envelope protein VP26, and their interaction was confirmed by GST pull-down assay. Further investigation showed that the VP52B binding domain was located between residues 135-170 of VP26. These findings will enhance our understanding of the molecular mechanisms of WSSV morphogenesis.
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Degeneration and Regeneration of GABAergic Interneurons in the Dentate Gyrus of Adult Mice in Experimental Models of Epilepsy.
CNS Neurosci Ther
PUBLISHED: 07-12-2014
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Mounting evidence showed that GABAergic interneurons play an important role in the generation of seizures by regulating excitatory/inhibitory balance in the hippocampus; however, there is a continuous debate regarding the alteration in the number of hippocampal GABAergic interneurons during epileptogenesis. Here, we investigated the degeneration and regeneration of GABAergic interneurons in the dentate gyrus during epileptogenesis using glutamic acid decarboxylase-green fluorescence protein (GAD67-GFP) knock-in mice.
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A comparative study of different level interpolations for improving spatial resolution in diffusion tensor imaging.
IEEE J Biomed Health Inform
PUBLISHED: 07-12-2014
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This paper studies and evaluates the feasibility and the performance of different level interpolations for improving spatial resolution of diffusion tensor magnetic resonance imaging (DT-MRI or DTI). In particular, the following techniques are investigated: anisotropic interpolation operating on scalar gray-level images, log-Euclidean interpolation method, and the quaternion interpolation method, which operate on diffusion tensor fields. The performance is evaluated both qualitatively and quantitatively using criteria such as tensor determinant, fractional anisotropy (FA), mean diffusivity (MD), fiber length, etc. We conclude that tensor field interpolations allow avoiding undesirable swelling effect in DTI, which is not the case with scalar gray-level interpolation, and that scalar gray-level image interpolation and log-Euclidean tensor field interpolation suffer from decrease in FA and MD, which may mislead the interpretation of the clinical parameters FA and MD. In contrast, the quaternion tensor field interpolation avoids such FA and MD decrease, which suggests its use for clinical applications.
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MicroRNA-218 inhibits cell invasion and migration of pancreatic cancer via regulating ROBO1.
Cancer Biol. Ther.
PUBLISHED: 07-10-2014
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miRNA-218 is a highlighted tumor suppressor and its underlying role in tumor progression is still unknown. Here, we restored the expression of miRNA-218 in pancreatic cancer to clarify the function and potent downstream pathway of miRNA-218. The expressions of both miRNA-218 and its potent target gene ROBO1 were revealed by RT-PCR and western blotting analysis. Transfection of miRNA-218 precursor mimics and luciferase assay were performed to elucidate the regulation mechanism between miRNA-218 and ROBO1. Cells, stably expressing miRNA-218 followed by forced expression of mutant ROBO1, were established through co-transfections of both lentivirus vector and plasmid vector. The cell migration and invasion abilities were evaluated by migration assay and invasion assay respectively. An increased expression of ROBO1 was revealed in cell BxPC-3-LN compared with cell BxPC-3. Elevated expression of miRNA-218 would suppress the expression of ROBO1 via complementary binding to a specific region within 3'UTR of ROBO1 mRNA (sites 971-978) in pancreatic cancer cells. Stably restoring the expression of miRNA-218 in pancreatic cancer significantly downregulated the expression of ROBO1 and effectively inhibited cell migration and invasion. Forced expression of mutant ROBO1 could reverse the repression effects of miRNA-218 on cell migration and invasion. Consequently, miRNA-218 acted as a tumor suppressor in pancreatic cancer by inhibiting cell invasion and migration. ROBO1 was a functional target of miRNA-218's downstream pathway involving in cell invasion and migration of pancreatic cancer.
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Note: High-efficiency broadband acoustic energy harvesting using Helmholtz resonator and dual piezoelectric cantilever beams.
Rev Sci Instrum
PUBLISHED: 07-03-2014
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A high-efficiency broadband acoustic energy harvester consisting of a compliant-top-plate Helmholtz resonator (HR) and dual piezoelectric cantilever beams is proposed. Due to the high mechanical quality factor of beams and the strong multimode coupling of HR cavity, top plate and beams, the high efficiency in a broad bandwidth is obtained. Experiment exhibits that the proposed harvester at 170-206 Hz has 28-188 times higher efficiency than the conventional harvester using a HR with a piezoelectric composite diaphragm. For input acoustic pressure of 2.0 Pa, the proposed harvester exhibits 0.137-1.43 mW output power corresponding to 0.035-0.36 ?W?cm(-3) volume power density at 170-206 Hz.
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The linker region of NS3 plays a critical role in the replication and infectivity of hepatitis C virus.
J. Virol.
PUBLISHED: 06-25-2014
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Hepatitis C virus (HCV) NS3-4A is required for viral replication and assembly. We establish that virus assembly is sensitive to mutations in the linker region between the helicase and protease domains of NS3-4A. However, we find that the protease cleavage, RNA binding, and unwinding rates of NS3 are minimally affected in vitro. Thus, we conclude that the NS3 linker is critical for mediating protein-protein interactions and dynamic control rather than for modulating the enzymatic functions of NS3-4A.
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DNA repair gene XRCC1 Arg194Trp polymorphism and susceptibility to hepatocellular carcinoma: A meta-analysis.
Oncol Lett
PUBLISHED: 06-24-2014
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The arginine194tryptophan (Arg194Trp) polymorphism in the X-ray repair cross-complementing group 1 (XRCC1) gene has been reported to be associated with hepatocellular carcinoma (HCC), however, the results from previous studies are conflicting. The present study aimed to investigate the association between the XRCC1 Arg194Trp polymorphism and the risk of HCC, using a meta-analysis of previously published studies. PubMed (http://www.ncbi.nlm.nih.gov/pubmed/), Google Scholar (http://scholar.google.co.uk/) and the China National Knowledge Infrastructure databases (http://www.cnki.net/) were systematically searched to identify relevant studies published prior to October 2013. A meta-analysis was performed to examine the association between the Arg194Trp gene polymorphism and the susceptibility to HCC. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. The meta-analysis consisted of six case-control studies that included 1,451 HCC cases and 1,398 healthy controls. Meta-analysis results based on all the studies showed no significant association between the XRCC1 Arg194Trp gene polymorphism and the risk of HCC (Trp/Trp vs. Arg/Arg: OR, 1.17; 95% CI, 0.89-1.55; Trp/Trp vs. Arg/Trp: OR, 0.94; 95% CI, 0.59-1.51; dominant model: OR, 0.97; 95% CI, 0.63-1.49; recessive model: OR, 1.22; 95% CI, 0.89-1.67). In the subgroup analysis, three studies with sample sizes of >300 produced similar results that indicated that the Arg194Trp gene polymorphism had no association with an increased or decreased risk of HCC. The pooled ORs were not markedly different following the exclusion of two studies deviating from the Hardy-Weinberg equilibrium in the control group, which indicated the reliability of the meta-analysis results. In conclusion, the XRCC1 Arg194Trp polymorphism may not be a risk or protective factor for HCC. Further large and well-designed studies are required to confirm these results.
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Perturbation training can reduce community-dwelling older adults' annual fall risk: a randomized controlled trial.
J. Gerontol. A Biol. Sci. Med. Sci.
PUBLISHED: 06-24-2014
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Previous studies indicated that a single session of repeated-slip exposure can reduce over 40% of laboratory-induced falls among older adults. The purpose of this study was to determine to what degree such perturbation training translated to the reduction of older adults' annual falls risk in their everyday living.
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Voltammetric determination of TBHQ at a glassy carbon electrode surface activated by in situ chemical oxidation.
Analyst
PUBLISHED: 06-03-2014
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In this article, a bare glassy carbon electrode (GCE) surface was directly activated by a simple in situ chemical method, which was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Based on these results, it was found that oxygen-containing functional groups at the modified GCE surface were enhanced with a low damage to the surface state. Hence, the modified GCE exhibited an excellent performance, such as the negatively charged surface, good reproducibility and high selectivity. The resulting electrode was applied as a sensitive sensor for detection of antioxidant tertiary butyl hydroquinone (TBHQ), and a good linear relationship was obtained between the oxidation peak current and the concentration in a broad range of 1.0 ?M-1.1 mM, with detection limits of 67 nM (S/N = 3) by DPV. Electrochemical parameters of TBHQ on the resulting GCE were also investigated, suggesting that the modified GCE could promote electron transfer kinetics towards the electrochemical reaction of TBHQ. Besides, the present method was used for determination of TBHQ in jatropha biodiesel with recovery ranging from 95.2% to 103.2%.
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[Tumor segmentation on multi-modality magnetic resonance images based on SVM model parameter optimization].
Nan Fang Yi Ke Da Xue Xue Bao
PUBLISHED: 05-23-2014
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To develop a method for tumor segmentation on multi-modality magnetic resonance (MR) images based on parameter optimization of SVM model.
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[Thoughts and methods of study on acupuncture medical history: an example of Mr. MA Ji-Xing].
Zhongguo Zhen Jiu
PUBLISHED: 05-22-2014
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Mr. MA Ji-xing has devoted himself into the study of acupuncture medical history for more than 70 years. As a result, a great work of Zhenjiuxue Tongshi (see text), History of Acupuncture-Moxibustion) has been completed. The author has expensively studied for history of acupuncture medicine in time and space. Base on abundant historical materials, deliberate textual research as well as strategically situated academic view, it is considered as a masterpiece of acupuncture on real significance. It is worthwhile to note that the book has a systematic and profound explanation on Bian-stone therapy, unearthed literature relics of acupuncture, the bronze figure or illustration of acupoint as well as special topics of Japan and Korea acupuncture history. Filled several gaps of the field, and explored some significant new paths of study, it laid the groundwork for the profound study and unscramble of traditional acupuncture theory as well as the investigation of the academic history, which is considered to have a profound and persistent influence. The careful sorting and profound digging of many distinguish thoughts and methods of Mr. MA Ji-xing in the study of acupuncture medical history has significant meaning in references and enlightenment of the future research on acupuncture medical history.
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[Effects of reduced N application rate on yield and nutrient uptake and utilization in maize-soybean relay strip intercropping system].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 05-17-2014
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A field experiment with three N application rates (0, 180, 240 N kg x hm(-2), representing zero, reduced and conventional N application, respectively) and three planting patterns (maize monoculture, soybean monoculture and maize-soybean relay strip intercropping) was conducted to reveal the effects of cropping patterns and N application rates on yield, nutrient uptake and nitrogen use efficiency of maize and soybean. The results showed that the grain yield, N, P and K uptake and harvest index of the intercropped maize reduced slightly compared with the monoculture maize, however these indices of the intercropped soybean increased significantly compared with the monoculture. With the increase in nitrogen fertilizer application, the excellence of relay strip intercropping was weakened in the maize-soybean intercropping system. The grain yield, economic coefficient, N, P and K uptake, harvest index, N agronomy efficiency and N uptake efficiency of maize and soybean increased significantly at the reduced nitrogen rate (180 N kg x hm(-2)), but the rate of soil N contribution declined, compared with the conventional rate of N application by local farmers (240 N kg x hm(-2)). In the reduced nitrogen rate treatment, total soil N and P contents of the maize strip reduced, whereas the total soil N, P and K contents of soybean strip and the total K content of maize strip increased compared with the zero N application treatment. With the reduced N application, the annual total grain yield, N, P and K uptake of above-ground biomass in the maize-soybean relay strip intercropping system were higher than in the monoculture, and the land equivalent ratio (LER) was 2.28. N uptake efficiency of maize in the relay strip intercropping system was 20.2% higher than in the maize monoculture, and the index of soybean was 30.5% lower than in the monoculture. The rate of soil N contribution in the relay strip intercropping system was 20.0% and 8.8% lower than in the maize and soybean monoculture, respectively. The reduced N application in the maize-soybean relay strip intercropping system was helpful to promote annual grain yield and improve N utilization efficiency.
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WFDC1 Is a Key Modulator of Inflammatory and Wound Repair Responses.
Am. J. Pathol.
PUBLISHED: 05-11-2014
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WFDC1/ps20 is a whey acidic protein four-disulfide core member that exhibits diverse growth and immune-associated functions in vitro. In vivo functions are unknown, although WFDC1 is lower in reactive stroma. A Wfdc1-null mouse was generated to assess core functions. Wfdc1-null mice exhibited normal developmental and adult phenotypes. However, homeostasis challenges affected inflammatory and repair processes. Wfdc1-null mice infected with influenza A exhibited 2.75-log-fold lower viral titer relative to control mice. Wfdc1-null infected lungs exhibited elevated macrophages and deposition of osteopontin, a potent macrophage chemokine. In wounding studies, Wfdc1-null mice exhibited an elevated rate of skin closure, and this too was associated with elevated deposition of osteopontin and macrophage recruitment. Wfdc1-null fibroblasts exhibited impaired spheroid formation, elevated adhesion to fibronectin, and an increased rate of wound closure in vitro. This was reversed by neutralizing antibody to osteopontin. Osteopontin mRNA and cleaved protein was up-regulated in Wfdc1-null cells treated with lipopolysaccharide or polyinosinic-polycytidylic acid coordinate with constitutively active matrix metallopeptidase-9 (MMP-9), a protease that cleaves osteopontin. These data suggest that WFDC1/ps20 modulates core host response mechanisms, in part, via regulation of osteopontin and MMP-9 activity. Release from WFDC1 regulation is likely a key component of inflammatory and repair response mechanisms, and involves the processing of elevated osteopontin by activated MMP-9, and subsequent macrophage recruitment.
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Identification and characterization of a novel phage-type like lysozyme from Manila clam, Ruditapes philippinarum.
Dev. Comp. Immunol.
PUBLISHED: 05-09-2014
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A novel lysozyme gene (RpLysPh) with high similarity to the bacteriophage lysozymes was identified in Manila clam, Ruditapes philippinarum. The full length cDNA of RpLysPh is 828bp and contains a 462bp open reading frame (ORF) that codes for a 154 amino acid protein. Multiple sequence alignment analysis revealed that the three residues essential for catalytic activity in phage-type lysozyme (Glu(20), Asp(29), and Thr(35)) are conserved in RpLysPh. The comparison of the 3D models of RpLysPh and Coxiella burnetii lysozyme also suggested that the active sites involved in the binding of substrate have similar conformations. Phylogenetic analysis suggested that RpLysPh shares a similar origin with the bacterial phage-type lysozyme group. The highest level of expression of RpLysPh was observed in hemocytes, followed by mantle. Induction of RpLysPh expression was observed in gills in response to lipopolysaccharide (LPS), peptidoglycan (PGN), polyinosinic-polycytidylic acid (Poly(I:C)), and whole glucan particles (WGP) challenge. The recombinant protein of RpLysPh showed antibacterial activity against both Gram-positive and Gram-negative bacteria.
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Cross-cultural validation of the National Eye Institute Visual Function Questionnaire.
J Cataract Refract Surg
PUBLISHED: 04-29-2014
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To assess the native and the previously Rasch-modified National Eye Institute Visual Function Questionnaire (NEI VFQ) scales in a Chinese population.
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Dynamic stability and compensatory stepping responses during anterior gait-slip perturbations in people with chronic hemiparetic stroke.
J Biomech
PUBLISHED: 04-23-2014
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To examine the control of dynamic stability and characteristics of the compensatory stepping responses to an unexpected anterior gait slip induced under the non-involved limb in people with hemi-paretic stroke (PwHS) and to examine any resulting adaptive changes in these on the second slip due to experience from prior slip exposure. Ten PwHS experienced overground slip (S1) during walking on the laboratory walkway after 5-8 regular walking (RW) trials followed by a second consecutive slip trial (S2). The slip outcome (backward loss of balance, BLOB and no loss of balance, NLOB) and COM state (i.e. its COM position and velocity) stability were examined between the RW and S1 and S1 and S2 at touchdown (TD) of non-involved limb and at liftoff (LO) of the contralateral limb. At TD there was no difference in stability between RW and S1, however at LO, subjects demonstrated a lower stability on S1 than RW resulting in a 100% backward loss of balance (BLOB) with compensatory stepping response (recovery step, RS, 4/10 or aborted step, AS, 6/10). On S2, although there was no change in stability at TD, there was a significant improvement in stability at LO with a 40% decrease in BLOB. There was also a change in step strategy with a decrease in AS response (60% to 35%, p<0.05) which was replaced by an increase in the ability to step (increased compensatory step length, p<0.05) either via a recovery step or a walkover step. PwHS have the ability to reactively control COM state stability to decrease fall-risk upon a novel slip; prior exposure to a slip did not significantly alter feedforward control but improved the ability to use such feedback control for improved slip outcomes.
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Chirality-specific growth of single-walled carbon nanotubes on solid alloy catalysts.
Nature
PUBLISHED: 04-17-2014
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Carbon nanotubes have many material properties that make them attractive for applications. In the context of nanoelectronics, interest has focused on single-walled carbon nanotubes (SWNTs) because slight changes in tube diameter and wrapping angle, defined by the chirality indices (n,?m), will shift their electrical conductivity from one characteristic of a metallic state to one characteristic of a semiconducting state, and will also change the bandgap. However, this structure-function relationship can be fully exploited only with structurally pure SWNTs. Solution-based separation methods yield tubes within a narrow structure range, but the ultimate goal of producing just one type of SWNT by controlling its structure during growth has proved to be a considerable challenge over the last two decades. Such efforts aim to optimize the composition or shape of the catalyst particles that are used in the chemical vapour deposition synthesis process to decompose the carbon feedstock and influence SWNT nucleation and growth. This approach resulted in the highest reported proportion, 55 per cent, of single-chirality SWNTs in an as-grown sample. Here we show that SWNTs of a single chirality, (12,?6), can be produced directly with an abundance higher than 92 per cent when using tungsten-based bimetallic alloy nanocrystals as catalysts. These, unlike other catalysts used so far, have such high melting points that they maintain their crystalline structure during the chemical vapour deposition process. This feature seems crucial because experiment and simulation both suggest that the highly selective growth of (12,?6) SWNTs is the result of a good structural match between the carbon atom arrangement around the nanotube circumference and the arrangement of the catalytically active atoms in one of the planes of the nanocrystal catalyst. We anticipate that using high-melting-point alloy nanocrystals with optimized structures as catalysts paves the way for total chirality control in SWNT growth and will thus promote the development of SWNT applications.
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Reduced intensity in gait-slip training can still improve stability.
J Biomech
PUBLISHED: 04-17-2014
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Perturbation training with "free" slips (i.e., with long slip distance) has been able to successfully improve stability and to reduce the incidence of falls among older adults. Yet, it is unclear whether a highly constrained training with reduced slip distance (and hence training intensity) can achieve similar effects. The purpose of this study was to investigate whether short-distance slips could also improve the control of stability, and whether such improvements could be generalized to a novel, "free" slip. Thirty-six young subjects were randomly assigned to either one of the two training groups, which underwent seven training trials with constrained slips of either 12-cm or 18-cm in distance before encountering a novel, "free" slip (up to 150 cm) in the test trial; or the control group, which only experienced the same test trial of a novel, "free" slip. The results showed that while both training groups were able to significantly improve their control of stability in training; the 18-cm group had significantly better reactive control of stability than the 12-cm group. During the "free" slip, such advantage enabled the 18-cm group to exhibit significantly less balance loss incidence than 12-cm group (58.3 vs. 83.3%) and the controls (100%). These differences could be fully accounted for when we assume that the central nervous system directly controls slip velocity or slip distance during adaptation, whereby the level of similarity between training trials and the test trial governs the degree of generalization. The findings that low intensity training may still improve stability warrant further investigations among older adults.
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Effects of intra-aortic balloon pump on cerebral blood flow during peripheral venoarterial extracorporeal membrane oxygenation support.
J Transl Med
PUBLISHED: 04-14-2014
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The addition of an intra-aortic balloon pump (IABP) during peripheral venoarterial extracorporeal membrane oxygenation (VA ECMO) support has been shown to improve coronary bypass graft flows and cardiac function in refractory cardiogenic shock after cardiac surgery. The purpose of this study was to evaluate the impact of additional IABP support on the cerebral blood flow (CBF) in patients with peripheral VA ECMO following cardiac procedures.
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Ischemia in tumors induces early and sustained phosphorylation changes in stress kinase pathways but does not affect global protein levels.
Mol. Cell Proteomics
PUBLISHED: 04-09-2014
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Protein abundance and phosphorylation convey important information about pathway activity and molecular pathophysiology in diseases including cancer, providing biological insight, informing drug and diagnostic development, and guiding therapeutic intervention. Analyzed tissues are usually collected without tight regulation or documentation of ischemic time. To evaluate the impact of ischemia, we collected human ovarian tumor and breast cancer xenograft tissue without vascular interruption and performed quantitative proteomics and phosphoproteomics after defined ischemic intervals. Although the global expressed proteome and most of the >25,000 quantified phosphosites were unchanged after 60 min, rapid phosphorylation changes were observed in up to 24% of the phosphoproteome, representing activation of critical cancer pathways related to stress response, transcriptional regulation, and cell death. Both pan-tumor and tissue-specific changes were observed. The demonstrated impact of pre-analytical tissue ischemia on tumor biology mandates caution in interpreting stress-pathway activation in such samples and motivates reexamination of collection protocols for phosphoprotein analysis.
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Enhancer Activation Requires trans-Recruitment of a Mega Transcription Factor Complex.
Cell
PUBLISHED: 04-03-2014
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Enhancers provide critical information directing cell-type-specific transcriptional programs, regulated by binding of signal-dependent transcription factors and their associated cofactors. Here, we report that the most strongly activated estrogen (E2)-responsive enhancers are characterized by trans-recruitment and in situ assembly of a large 1-2 MDa complex of diverse DNA-binding transcription factors by ER? at ERE-containing enhancers. We refer to enhancers recruiting these factors as mega transcription factor-bound in trans (MegaTrans) enhancers. The MegaTrans complex is a signature of the most potent functional enhancers and is required for activation of enhancer RNA transcription and recruitment of coactivators, including p300 and Med1. The MegaTrans complex functions, in part, by recruiting specific enzymatic machinery, exemplified by DNA-dependent protein kinase. Thus, MegaTrans-containing enhancers represent a cohort of functional enhancers that mediate a broad and important transcriptional program and provide a molecular explanation for transcription factor clustering and hotspots noted in the genome.
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[Effects of electroacupuncture intervention on expression of hypothalamic PI 3 K and p-PI 3 K Proteins in insulin resistance model rats].
Zhen Ci Yan Jiu
PUBLISHED: 04-02-2014
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To observe the effect of "Shuanggu Yitong" (Double-reinforcing and one-unblocking) needling [electroacupuncture (EA) of "Guanyuan" (CV 4), "Housanli" (ST 36), "Fenglong" (ST 40) and "Zhongwan" (CV 12)] on expression of hypothalamic phosphatidylinositol 3-kinase (PI 3 K) and p-PI 3 K proteins in insulin resistance rats.
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In vivo Analysis of Cervical Range of Motion after Revised C1-C2 Pedicle Screw Technique for Pediatric Atlantoaxial Instability.
Pediatr Neurosurg
PUBLISHED: 03-31-2014
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Objective: The purpose of this study was to analyze the cervical range of motion (ROM) after revised C1-C2 pedicle screw fixation for pediatric patients with atlantoaxial instability. Methods: 17 pediatric patients (age range 5-14 years; mean 8.3 years) underwent the revised C1-C2 pedicle screw technique. Pre- and postoperative cervical ROM during flexion/extension, rotation and lateral bending were measured using a head-mounted motion goniometer. Plain radiographs, CT scans and MRI were performed to assess spinal cord compression, the accuracy of screw placement, and bone fusion. The American Spinal Injury Association classification was used to evaluate neurological function. Results: Revised atlantoaxial pedicle screw fixation was successfully performed in all 17 pediatric patients. There were no perioperative complications. All cases showed evidence of bone fusion 6 months after surgery by CT scan. During the follow-up period (24-92 months), of 6 patients with preoperative myelopathy, 3 improved from grade D to grade E and 3 from grade C to grade D. The final follow-up cervical ROM was significantly greater than the preoperative and 6-month postoperative ROM. There was a statistically significant difference between preoperative and 6-month postoperative ROM for flexion, extension, and left and right axial rotation movements. Conclusion: As a short-segmental fixation technique, revised C1-C2 pedicle screw fixation can provide effective biomechanical stability. Final follow-up cervical ROM is significantly increased through alleviating cervical pain and symptoms of myelopathy after surgery and possible subaxial compensation. © 2014 S. Karger AG, Basel.
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Establishment of an orthotopic pancreatic cancer mouse model: cells suspended and injected in Matrigel.
World J. Gastroenterol.
PUBLISHED: 03-24-2014
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To establish an orthotopic mouse model of pancreatic cancer that mimics the pathological features of exocrine pancreatic adenocarcinoma.
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Environmental cadmium exposure impacts physiological responses in Manila clams.
Biol Trace Elem Res
PUBLISHED: 03-24-2014
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The physiological responses of marine bivalves to chronic cadmium (Cd) exposure at sub-lethal concentrations have been well documented. As of now, few studies have examined the effect of Cd exposure and subsequent recovery period at environmentally realistic concentrations. In this study, environmentally, Cd exposures were performed to assess the physiological responses of the Manila clam Ruditapes philippinarum. The clams were exposed to waterborne Cd at two environmentally realistic concentrations (4 and 40 ?g L(-1)) for 35 days and then allowed to recover for another 35 days. The accumulation and elimination of Cd in R. philippinarum were tissue-specific and dose- and time-dependent. Cd accumulation increased sharply in the digestive gland, and Cd elimination was rapid in the gill. Major physiological responses, including clearance rate, absorption efficiency, respiration rate, excretion rate, oxygen to nitrogen ratio, and scope for growth, were significantly affected by Cd exposure. Yet, the clams exposed to 4-?g L(-1) Cd were able to quickly recover their normal physiological processes and clearly exhibited catch-up growth once they were transferred to clean seawater. Hence, R. philippinarum can exhibit good physiological plasticity when confronted with moderately environmental Cd exposure. All physiological responses measured exhibited a highly significant and generally predictable correlation with tissue Cd concentration, which in turn, reflected environmentally realistic exposure conditions. Our results further confirm that the measurement of physiological responses is a sensitive method for assessing stress at environmentally realistic metal concentrations.
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Biocomputional construction of a gene network under acid stress in Synechocystis sp. PCC 6803.
Res. Microbiol.
PUBLISHED: 03-18-2014
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Acid stress is one of the most serious threats that cyanobacteria have to face, and it has an impact at all levels from genome to phenotype. However, very little is known about the detailed response mechanism to acid stress in this species. We present here a general analysis of the gene regulatory network of Synechocystis sp. PCC 6803 in response to acid stress using comparative genome analysis and biocomputational prediction. In this study, we collected 85 genes and used them as an initial template to predict new genes through co-regulation, protein-protein interactions and the phylogenetic profile, and 179 new genes were obtained to form a complete template. In addition, we found that 11 enriched pathways such as glycolysis are closely related to the acid stress response. Finally, we constructed a regulatory network for the intricate relationship of these genes and summarize the key steps in response to acid stress. This is the first time a bioinformatic approach has been taken systematically to gene interactions in cyanobacteria and the elaboration of their cell metabolism and regulatory pathways under acid stress, which is more efficient than a traditional experimental study. The results also provide theoretical support for similar research into environmental stresses in cyanobacteria and possible industrial applications.
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Adsorption of HCN on reduced graphene oxides: a first-principles study.
J Mol Model
PUBLISHED: 03-16-2014
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The interactions between HCN and reduced graphene oxides (rGO) are investigated using first-principles calculations with M06-2X functional. The results show that the adsorption of HCN on rGO is generally stronger than that on graphene, which is due to the presence of the active defect sites in rGO, such as the hydroxyl, epoxide, and carboxyl functional groups and even the carbon atom near these groups. The interaction between HCN and rGO with oxygen-containing group can result in the formation of hydrogen bonds, N?·?·?·?H and O?·?·?·?H. The adsorption of HCN on rGO depends on the type and location of oxygen-containing group in rGO. Carboxyl group on rGO is much more attractive for HCN than hydroxyl and epoxide group. The adsorption of HCN is much stronger in rGO with oxygen-containing group on the surface than that at the edge. The adsorption of HCN on rGO with carboxyl attached to vacancy on the surface is the strongest.
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Learning from laboratory-induced falling: long-term motor retention among older adults.
Age (Dordr)
PUBLISHED: 03-04-2014
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Falls in older adults are a major health and societal problem. It is thus imperative to develop highly effective training paradigms to reduce the likelihood of falls. Perturbation training is one such emerging paradigm known to induce shorter term fall reduction in healthy young as well as older adults. Its longer term benefits are not fully understood, however. The purpose of this study was to determine whether and to what degree older adults could retain their fall-resisting skills acquired from a single perturbation training session. Seventy-three community-dwelling older adults (?65 years) received identical single-session perturbation training consisting of 24 slips. This was delivered through unannounced unlocking (and mixed with relocking) of low-friction movable sections of the walkway. A single retest was subsequently scheduled based on a three-stage sequential, pre-post-retest design. Outcome measurements, taken upon the first (novel) and the 24th (final) slips of the initial session and the retest slip, included fall-or-no-fall and stability (quantified by the shortest distance from relative motion state of the center-of-mass and the base-of-support to the limits of stability) at instants prior to (proactive) and after (reactive) the onset of the slip. The training boosted subjects' resilience against laboratory-induced falls demonstrated by a significant reduction from 42.5 % falls on the first slip to 0 % on the 24th slip. Rate of falls which occurred during the laboratory retest remained low in 6-month (0 %), 9-month (8.7 %), and 12-month retest (11.5 %), with no significant difference between the three time intervals. Such reduction of laboratory-induced falls and its retention were attributable to the significant training-induced improvement in the proactive and reactive control of stability. This unique pre-post-retest design enabled us to provide scientific basis for the feasibility of a single session of perturbation training to "inoculate" older adults and to reduce their annual risk of falls in everyday living.
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High-mobility transport anisotropy and linear dichroism in few-layer black phosphorus.
Nat Commun
PUBLISHED: 02-27-2014
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Two-dimensional crystals are emerging materials for nanoelectronics. Development of the field requires candidate systems with both a high carrier mobility and, in contrast to graphene, a sufficiently large electronic bandgap. Here we present a detailed theoretical investigation of the atomic and electronic structure of few-layer black phosphorus (BP) to predict its electrical and optical properties. This system has a direct bandgap, tunable from 1.51 eV for a monolayer to 0.59 eV for a five-layer sample. We predict that the mobilities are hole-dominated, rather high and highly anisotropic. The monolayer is exceptional in having an extremely high hole mobility (of order 10,000 cm(2) V(-1) s(-1)) and anomalous elastic properties which reverse the anisotropy. Light absorption spectra indicate linear dichroism between perpendicular in-plane directions, which allows optical determination of the crystalline orientation and optical activation of the anisotropic transport properties. These results make few-layer BP a promising candidate for future electronics.
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Adaptation of Candida albicans to growth on sorbose via monosomy of chromosome 5 accompanied by duplication of another chromosome carrying a gene responsible for sorbose utilization.
FEMS Yeast Res.
PUBLISHED: 02-26-2014
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Candida albicans, a fungus that normally inhabits the digestive tract and other mucosal surfaces, can become a pathogen in immunocompromised individuals, causing severe or even fatal infection. Mechanisms by which C. albicans can evade commonly used antifungal agents are not fully understood. We are studying a model system involving growth of C. albicans on toxic sugar sorbose, which represses synthesis of cell wall glucan and, as a result, kills fungi in a manner similar to drugs from the echinocandins class. Adaptation to sorbose occurs predominantly due to reversible loss of one homolog of chromosome 5 (Ch5), which results in upregulation of the metabolic gene SOU1 (SOrbose Utilization) on Ch4. Here, we show that growth on sorbose due to Ch5 monosomy can involve a facultative trisomy of a hybrid Ch4/7 that serves to increase copy number of the SOU1 gene. This shows that control of expression of SOU1 can involve multiple mechanisms; in this case, negative regulation and increase in gene copy number operating simultaneously in cell.
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DNA binding, cytotoxicity and apoptosis induction activity of a mixed-ligand copper(II) complex with taurine Schiff base and imidazole.
Spectrochim Acta A Mol Biomol Spectrosc
PUBLISHED: 02-26-2014
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A novel binuclear copper(II) complex (complex 1) with taurine Schiff base and imidazole has been synthesized and structurally characterized by single crystal X-ray diffraction, elemental analysis, ESI-MS spectrometry, UV-vis and IR spectroscopy. Single-crystal analysis revealed that 1 displays the sulfonate-bridged dinuclear copper(II) centers. Both copper atoms are five-coordinated and exhibit slightly distorted square pyramidal geometries. Each of copper atom is surrounded by three oxygen atoms and one nitrogen atom from different taurine Schiff base ligands, and one nitrogen atom from one imidazole ligand. The interaction between 1 and calf thymus DNA (CT-DNA) was investigated by UV-vis, fluorescence, circular dichroism (CD) spectra and agarose gel electrophoresis. The experimental results indicated that 1 could bind to CT-DNA via an intercalative mode and show efficient cleavage activity. In addition, 1 showed an antitumor effect on cell cycle and apoptosis. Flow cytometric analysis revealed that MGC-803 cells were arrested in the S phase after treatment with 1. Fluorescence microscopic observation indicated that 1 could induce apoptosis of MGC-803 cells.
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Adaptive control of center of mass (global) motion and its joint (local) origin in gait.
J Biomech
PUBLISHED: 02-25-2014
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Dynamic gait stability can be quantified by the relationship of the motion state (i.e. the position and velocity) between the body center of mass (COM) and its base of support (BOS). Humans learn how to adaptively control stability by regulating the absolute COM motion state (i.e. its position and velocity) and/or by controlling the BOS (through stepping) in a predictable manner, or by doing both simultaneously following an external perturbation that disrupts their regular relationship. Post repeated-slip perturbation training, for instance, older adults learned to forward shift their COM position while walking with a reduced step length, hence reduced their likelihood of slip-induced falls. How and to what extent each individual joint influences such adaptive alterations is mostly unknown. A three-dimensional individualized human kinematic model was established. Based on the human model, sensitivity analysis was used to systematically quantify the influence of each lower limb joint on the COM position relative to the BOS and the step length during gait. It was found that the leading foot had the greatest effect on regulating the COM position relative to the BOS; and both hips bear the most influence on the step length. These findings could guide cost-effective but efficient fall-reduction training paradigm among older population.
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New researches and application progress of commonly used optical molecular imaging technology.
Biomed Res Int
PUBLISHED: 02-17-2014
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Optical molecular imaging, a new medical imaging technique, is developed based on genomics, proteomics and modern optical imaging technique, characterized by non-invasiveness, non-radiativity, high cost-effectiveness, high resolution, high sensitivity and simple operation in comparison with conventional imaging modalities. Currently, it has become one of the most widely used molecular imaging techniques and has been applied in gene expression regulation and activity detection, biological development and cytological detection, drug research and development, pathogenesis research, pharmaceutical effect evaluation and therapeutic effect evaluation, and so forth, This paper will review the latest researches and application progresses of commonly used optical molecular imaging techniques such as bioluminescence imaging and fluorescence molecular imaging.
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A New Stochastic Kriging Method for Modeling Multi-Source Exposure-Response Data in Toxicology Studies.
ACS Sustain Chem Eng
PUBLISHED: 02-16-2014
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One of the most fundamental steps in risk assessment is to quantify the exposure-response relationship for the material/chemical of interest. This work develops a new statistical method, referred to as SKQ (stochastic kriging with qualitative factors), to synergistically model exposure-response data, which often arise from multiple sources (e.g., laboratories, animal providers, and shapes of nanomaterials) in toxicology studies. Compared to the existing methods, SKQ has several distinct features. First, SKQ integrates data across multiple sources and allows for the derivation of more accurate information from limited data. Second, SKQ is highly flexible and able to model practically any continuous response surfaces (e.g., dose-time-response surface). Third, SKQ is able to accommodate variance heterogeneity across experimental conditions and to provide valid statistical inference (i.e., quantify uncertainties of the model estimates). Through empirical studies, we have demonstrated SKQ's ability to efficiently model exposure-response surfaces by pooling information across multiple data sources. SKQ fits into the mosaic of efficient decision-making methods for assessing the risk of a tremendously large variety of nanomaterials and helps to alleviate safety concerns regarding the enormous amount of new nanomaterials.
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Structural basis and anticancer properties of ruthenium-based drug complexed with human serum albumin.
Eur J Med Chem
PUBLISHED: 02-15-2014
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Ruthenium-based anticancer complexes have become increasingly popular for study over the last two decades. Although ruthenium complexes are currently being investigated in clinical trials, there are still some difficulties with their delivery and associated side effects. Human serum albumin (HSA)-based delivery systems are promising for improving anticancer drug targeting and reducing negative side effects. However, there have been few studies regarding the HSA delivery system for metal-based anticancer compounds and no mention of its structural mechanism. Therefore, we studied the structure and anticancer properties of the ruthenium-based compound [RuCl5(ind)](2-) in complex with HSA. The structure revealed that [RuCl5(ind)](2-) has two binding sites in HSA. In the IB subdomain, [RuCl5(ind)](2-) binds to a new sub-site by coordinating with His-146. In the IIA subdomain, ruthenium (III) of [RuCl5(ind)](2-) binds to the hydrophobic cavity and forms coordination bonds by replacing chlorine atoms with the His-242 and Lys-199 residues of HSA. Interestingly, [RuCl5(ind)](2-), together with HSA, can enhance cytotoxicity by two to five times in cancer cells but has no effect on normal cells in vitro. Compared with unbound drug, the HSA-[RuCl5(ind)](2-) complex promotes MGC-803 cell apoptosis and also has a stronger capacity for cell cycle arrest at the G2 phase in MGC-803. In conclusion, this study will guide the rational design and development of ruthenium-containing or ruthenium-centered drugs and an HSA delivery system for ruthenium-based drugs.
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Ultrasound-mediated local drug and gene delivery using nanocarriers.
Biomed Res Int
PUBLISHED: 02-14-2014
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With the development of nanotechnology, nanocarriers have been increasingly used for curative drug/gene delivery. Various nanocarriers are being introduced and assessed, such as polymer nanoparticles, liposomes, and micelles. As a novel theranostic system, nanocarriers hold great promise for ultrasound molecular imaging, targeted drug/gene delivery, and therapy. Nanocarriers, with the properties of smaller particle size, and long circulation time, would be advantageous in diagnostic and therapeutic applications. Nanocarriers can pass through blood capillary walls and cell membrane walls to deliver drugs. The mechanisms of interaction between ultrasound and nanocarriers are not clearly understood, which may be related to cavitation, mechanical effects, thermal effects, and so forth. These effects may induce transient membrane permeabilization (sonoporation) on a single cell level, cell death, and disruption of tissue structure, ensuring noninvasive, targeted, and efficient drug/gene delivery and therapy. The system has been used in various tissues and organs (in vitro or in vivo), including tumor tissues, kidney, cardiac, skeletal muscle, and vascular smooth muscle. In this review, we explore the research progress and application of ultrasound-mediated local drug/gene delivery with nanocarriers.
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New progress in angiogenesis therapy of cardiovascular disease by ultrasound targeted microbubble destruction.
Biomed Res Int
PUBLISHED: 02-13-2014
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Angiogenesis plays a vital part in the pathogenesis and treatment of cardiovascular disease and has become one of the hotspots that are being discussed in the past decades. At present, the promising angiogenesis therapies are gene therapy and stem cell therapy. Besides, a series of studies have shown that the ultrasound targeted microbubble destruction (UTMD) was a novel gene delivery system, due to its advantages of noninvasiveness, low immunogenicity and toxicity, repeatability and temporal and spatial target specificity; UTMD has also been used for angiogenesis therapy of cardiovascular disease. In this review, we mainly discuss the combination of UTMD and gene therapy or stem cell therapy which is applied in angiogenesis therapy in recent researches, and outline the future challenges and good prospects of these approaches.
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Advance of molecular imaging technology and targeted imaging agent in imaging and therapy.
Biomed Res Int
PUBLISHED: 02-13-2014
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Molecular imaging is an emerging field that integrates advanced imaging technology with cellular and molecular biology. It can realize noninvasive and real time visualization, measurement of physiological or pathological process in the living organism at the cellular and molecular level, providing an effective method of information acquiring for diagnosis, therapy, and drug development and evaluating treatment of efficacy. Molecular imaging requires high resolution and high sensitive instruments and specific imaging agents that link the imaging signal with molecular event. Recently, the application of new emerging chemical technology and nanotechnology has stimulated the development of imaging agents. Nanoparticles modified with small molecule, peptide, antibody, and aptamer have been extensively applied for preclinical studies. Therapeutic drug or gene is incorporated into nanoparticles to construct multifunctional imaging agents which allow for theranostic applications. In this review, we will discuss the characteristics of molecular imaging, the novel imaging agent including targeted imaging agent and multifunctional imaging agent, as well as cite some examples of their application in molecular imaging and therapy.
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Disease-modifying effects of RHC80267 and JZL184 in a pilocarpine mouse model of temporal lobe epilepsy.
CNS Neurosci Ther
PUBLISHED: 02-06-2014
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Patients with temporal lobe epilepsy (TLE) often suffer from comorbid psychiatric diagnoses such as depression, anxiety, or impaired cognitive performance. Endocannabinoid (eCB) signaling is a key regulator of synaptic neurotransmission and has been implicated in the mechanisms of epilepsy as well as several mood disorders and cognitive impairments.
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Antibody-independent targeted quantification of TMPRSS2-ERG fusion protein products in prostate cancer.
Mol Oncol
PUBLISHED: 01-29-2014
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Fusions between the transmembrane protease serine 2 (TMPRSS2) and ETS related gene (ERG) represent one of the most specific biomarkers that define a distinct molecular subtype of prostate cancer. Studies of TMPRSS2-ERG gene fusions have seldom been performed at the protein level, primarily due to the lack of high-quality antibodies suitable for quantitative studies. Herein, we applied a recently developed PRISM (high-pressure high-resolution separations with intelligent selection and multiplexing)-SRM (selected reaction monitoring) strategy for quantifying ERG protein in prostate cancer cell lines and tumors. The highly sensitive PRISM-SRM assays provided confident detection of 6 unique ERG peptides in both TMPRSS2-ERG positive cell lines and tissues, but not in cell lines or tissues lacking the TMPRSS2-ERG rearrangement, clearly indicating that ERG protein expression is significantly increased in the presence of the TMPRSS2-ERG gene fusion. Significantly, our results provide evidence that two distinct ERG protein isoforms are simultaneously expressed in TMPRSS2-ERG positive samples as evidenced by the concomitant detection of two mutually exclusive peptides in two patient tumors and in the VCaP prostate cancer cell line. Three peptides, shared across almost all fusion protein products, were determined to be the most abundant peptides, providing "signature" peptides for detection of ERG over-expression resulting from TMPRSS2-ERG gene fusion. The PRISM-SRM assays provide valuable tools for studying TMPRSS2-ERG gene fusion protein products in prostate cancer.
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Interleukin-1 beta guides the migration of cortical neurons.
J Neuroinflammation
PUBLISHED: 01-22-2014
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Proinflammatory cytokine interleukin-1beta (IL-1?) is expressed at high levels in the developing brain and declines to low constitutive levels in the adult. However, the pathophysiological function of IL-1? during brain development remains elusive. In this study, we investigated the role of IL-1? in neuronal migration.
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The proteome and phosphoproteome of Neurospora crassa in response to cellulose, sucrose and carbon starvation.
Fungal Genet. Biol.
PUBLISHED: 01-22-2014
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Improving cellulolytic enzyme production by plant biomass degrading fungi holds great potential in reducing costs associated with production of next-generation biofuels generated from lignocellulose. How fungi sense cellulosic materials and respond by secreting enzymes has mainly been examined by assessing function of transcriptional regulators and via transcriptional profiling. Here, we obtained global proteomic and phosphoproteomic profiles of the plant biomass degrading filamentous fungus Neurospora crassa grown on different carbon sources, i.e. sucrose, no carbon, and cellulose, by performing isobaric tags for relative and absolute quantification (iTRAQ)-based LC-MS/MS analyses. A comparison between proteomes and transcriptomes under identical carbon conditions suggests that extensive post-transcriptional regulation occurs in N. crassa in response to exposure to cellulosic material. Several hundred amino acid residues with differential phosphorylation levels on crystalline cellulose (Avicel) or carbon-free medium vs sucrose medium were identified, including phosphorylation sites in a major transcriptional activator for cellulase genes, CLR1, as well as a cellobionic acid transporter, CBT1. Mutation of phosphorylation sites on CLR1 did not have a major effect on transactivation of cellulase production, while mutation of phosphorylation sites in CBT1 increased its transporting capacity. Our data provides rich information at both the protein and phosphorylation levels of the early cellular responses to carbon starvation and cellulosic induction and aids in a greater understanding of the underlying post-transcriptional regulatory mechanisms in filamentous fungi.
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Utility of PET/CT in diagnosis, staging, assessment of resectability and metabolic response of pancreatic cancer.
World J. Gastroenterol.
PUBLISHED: 01-21-2014
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Pancreatic cancer is one of the most common gastrointestinal tumors, with its incidence staying at a high level in both the United States and China. However, the overall 5-year survival rate of pancreatic cancer is still extremely low. Surgery remains the only potential chance for long-term survival. Early diagnosis and precise staging are crucial to make proper clinical decision for surgery candidates. Despite advances in diagnostic technology such as computed tomography (CT) and endoscopic ultrasound, diagnosis, staging and monitoring of the metabolic response remain a challenge for this devastating disease. Positron emission tomography/CT (PET/CT), a relatively novel modality, combines metabolic detection with anatomic information. It has been widely used in oncology and achieves good results in breast cancer, lung cancer and lymphoma. Its utilization in pancreatic cancer has also been widely accepted. However, the value of PET/CT in pancreatic disease is still controversial. Will PET/CT change the treatment strategy for potential surgery candidates? What kind of patients benefits most from this exam? In this review, we focus on the utility of PET/CT in diagnosis, staging, and assessment of resectability of pancreatic cancer. In addition, its ability to monitor metabolic response and recurrence after treatment will be emphasis of discussion. We hope to provide answers to the questions above, which clinicians care most about.
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Clinical application of a revised screw technique via the C1 posterior arch and lateral mass in the pediatric population.
Pediatr Neurosurg
PUBLISHED: 01-16-2014
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Pediatric patients with insufficient height (?4 mm) of the C1 posterior arch may restrict atlas screw placement via the posterior arch and lateral mass (PALM). For these patients, we modified this technique, called the 'pedicle exposure technique' (PET). We aimed to analyze the clinical feasibility and safety of the PET in the pediatric population.
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Efficient construction of unmarked recombinant mycobacteria using an improved system.
J. Microbiol. Methods
PUBLISHED: 01-09-2014
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The genetic study of mycobacteria, such as Mycobacterium tuberculosis and Mycobacterium ulcerans, is hampered heavily by their slow growth. We have developed efficient, versatile, and improved genetic tools for constructing unmarked recombinant mycobacteria more rapidly including generating multiple mutants using the same antibiotic marker in both fast- and slow-growing mycobacteria.
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A 41-gene signature derived from breast cancer stem cells as a predictor of survival.
J. Exp. Clin. Cancer Res.
PUBLISHED: 01-07-2014
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The aim of this study was to evaluate the ability of a 41-gene signature derived from breast cancer stem cells (BCSCs) to estimate the risk of metastasis and survival in breast cancer patients.
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Is routine drainage necessary after pancreaticoduodenectomy?
World J. Gastroenterol.
PUBLISHED: 01-06-2014
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With the development of imaging technology and surgical techniques, pancreatic resections to treat pancreatic tumors, ampulla tumors, and other pancreatic diseases have increased. Pancreaticoduodenectomy, one type of pancreatic resection, is a complex surgery with the loss of pancreatic integrity and various anastomoses. Complications after pancreaticoduodenectomy such as pancreatic fistulas and anastomosis leakage are common and significantly associated with patient outcomes. Pancreatic fistula is one of the most important postoperative complications; this condition can cause intraperitoneal hemorrhage, septic shock, or even death. An effective way has not yet been found to avoid the occurrence of pancreatic fistula. In most medical centers, the frequency of pancreatic fistula has remained between 9% and 13%. The early detection and routine drainage of anastomotic fistulas, pancreatic fistulas, bleeding, or other intra-abdominal fluid collections after pancreatic resections are considered as important and effective ways to reduce postoperative complications and the mortality rate. However, many recent studies have argued that routine drainage after abdominal operations, including pancreaticoduodenectomies, does not affect the incidence of postoperative complications. Although inserting drains after pancreatic resections continues to be a routine procedure, its necessity remains controversial. This article reviews studies of the advantages and disadvantages of routine drainage after pancreaticoduodenectomy and discusses the necessity of this procedure.
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Anisotropic etching of graphite flakes with water vapor to produce armchair-edged graphene.
Small
PUBLISHED: 01-02-2014
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A one-step anisotropic etching method is developed to specifically obtain armchair-edged graphene directly from graphite flakes on various substrates. The armchair edge structure of the produced graphene is verified by the atomic resolution images obtained from the fluid mode peakforce tapping AFM and the relatively high intensity of D band in the Raman spectra.
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Palm-vein classification based on principal orientation features.
PLoS ONE
PUBLISHED: 01-01-2014
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Personal recognition using palm-vein patterns has emerged as a promising alternative for human recognition because of its uniqueness, stability, live body identification, flexibility, and difficulty to cheat. With the expanding application of palm-vein pattern recognition, the corresponding growth of the database has resulted in a long response time. To shorten the response time of identification, this paper proposes a simple and useful classification for palm-vein identification based on principal direction features. In the registration process, the Gaussian-Radon transform is adopted to extract the orientation matrix and then compute the principal direction of a palm-vein image based on the orientation matrix. The database can be classified into six bins based on the value of the principal direction. In the identification process, the principal direction of the test sample is first extracted to ascertain the corresponding bin. One-by-one matching with the training samples is then performed in the bin. To improve recognition efficiency while maintaining better recognition accuracy, two neighborhood bins of the corresponding bin are continuously searched to identify the input palm-vein image. Evaluation experiments are conducted on three different databases, namely, PolyU, CASIA, and the database of this study. Experimental results show that the searching range of one test sample in PolyU, CASIA and our database by the proposed method for palm-vein identification can be reduced to 14.29%, 14.50%, and 14.28%, with retrieval accuracy of 96.67%, 96.00%, and 97.71%, respectively. With 10,000 training samples in the database, the execution time of the identification process by the traditional method is 18.56 s, while that by the proposed approach is 3.16 s. The experimental results confirm that the proposed approach is more efficient than the traditional method, especially for a large database.
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TGF-? induction of FGF-2 expression in stromal cells requires integrated smad3 and MAPK pathways.
Am J Clin Exp Urol
PUBLISHED: 01-01-2014
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Transforming Growth Factor-? (TGF-?) regulates the reactive stroma microenvironment associated with most carcinomas and mediates expression of many stromal derived factors important for tumor progression, including FGF-2 and CTGF. TGF-? is over-expressed in most carcinomas, and FGF-2 action is important in tumor-induced angiogenesis. The signaling mechanisms of how TGF-? regulates FGF-2 expression in the reactive stroma microenvironment are not understood. Accordingly, we have assessed key signaling pathways that mediate TGF-?1-induced FGF-2 expression in prostate stromal fibroblasts and mouse embryo fibroblasts (MEFs) null for Smad2 and Smad3. TGF-?1 induced phosphorylation of Smad2, Smad3, p38 and ERK1/2 proteins in both control MEFs and prostate fibroblasts. Of these, Smad3, but not Smad2 was found to be required for TGF-?1 induction of FGF-2 expression in stromal cells. ChIP analysis revealed a Smad3/Smad4 complex was associated with the -1.9 to -2.3 kb upstream proximal promoter of the FGF-2 gene, further suggesting a Smad3-specific regulation. In addition, chemical inhibition of p38 or ERK1/2 MAPK activity also blocked TGF-?1-induced FGF-2 expression in a Smad3-independent manner. Conversely, inhibition of JNK signaling enhanced FGF-2 expression. Together, these data indicate that expression of FGF-2 in fibroblasts in the tumor stromal cell microenvironment is coordinately dependent on both intact Smad3 and MAP kinase signaling pathways. These pathways and key downstream mediators of TGF-? action in the tumor reactive stroma microenvironment, may evolve as putative targets for therapeutic intervention.
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Astrocytic expression of cannabinoid type 1 receptor in rat and human sclerotic hippocampi.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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Cannabinoid type 1 receptor (CB1R), which is traditionally located on axon terminals, plays an important role in the pathology of epilepsy and neurodegenerative diseases by modulating synaptic transmission. Using the pilocarpine model of chronic spontaneous recurrent seizures, which mimics the main features of mesial temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS) in humans, we examined the expression of CB1R in hippocampal astrocytes of epileptic rats. Furthermore, we also examined the expression of astrocytic CB1R in the resected hippocampi from patients with medically refractory mesial TLE. Using immunofluorescent double labeling, we found increased expression of astrocytic CB1R in hippocampi of epileptic rats, whereas expression of astrocytic CB1R was not detectable in hippocampi of saline treated animals. Furthermore, CB1R was also found in some astrocytes in sclerotic hippocampi in a subset of patients with intractable mesial TLE. Detection with immune electron microscopy showed that the expression of CB1R was increased in astrocytes of epileptic rats and modest levels of CB1R were also found on the astrocytic membrane of sclerotic hippocampi. These results suggest that increased expression of astrocytic CB1R in sclerotic hippocampi might be involved in the cellular basis of the effects of cannabinoids on epilepsy.
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iDrug: a web-accessible and interactive drug discovery and design platform.
J Cheminform
PUBLISHED: 01-01-2014
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The progress in computer-aided drug design (CADD) approaches over the past decades accelerated the early-stage pharmaceutical research. Many powerful standalone tools for CADD have been developed in academia. As programs are developed by various research groups, a consistent user-friendly online graphical working environment, combining computational techniques such as pharmacophore mapping, similarity calculation, scoring, and target identification is needed.
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Transcriptome analysis of shade-induced inhibition on leaf size in relay intercropped soybean.
PLoS ONE
PUBLISHED: 01-01-2014
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Multi-species intercropping is a sustainable agricultural practice worldwide used to utilize resources more efficiently. In intercropping systems, short crops often grow under vegetative shade of tall crops. Soybean, one important legume, is often planted in intercropping. However, little is known about the mechanisms of shade inhibition effect on leaf size in soybean leaves at the transcriptome level. We analyzed the transcriptome of shaded soybean leaves via RNA-Seq technology. We found that transcription 1085 genes in mature leaves and 1847 genes in young leaves were significantly affected by shade. Gene ontology analyses showed that expression of genes enriched in polysaccharide metabolism was down-regulated, but genes enriched in auxin stimulus were up-regulated in mature leaves; and genes enriched in cell cycling, DNA-replication were down-regulated in young leaves. These results suggest that the inhibition of higher auxin content and shortage of sugar supply on cell division and cell expansion contribute to smaller and thinner leaf morphology, which highlights potential research targets such as auxin and sugar regulation on leaves for crop adaptation to shade in intercropping.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

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

Video X seems to be unrelated to Abstract Y...

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.