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Find video protocols related to scientific articles indexed in Pubmed.
STIM1- and Orai1-mediated Ca2+ oscillation orchestrates invadopodium formation and melanoma invasion.
J. Cell Biol.
PUBLISHED: 11-19-2014
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Ca(2+) signaling has been increasingly implicated in cancer invasion and metastasis, and yet, the underlying mechanisms remained largely unknown. In this paper, we report that STIM1- and Orai1-mediated Ca(2+) oscillations promote melanoma invasion by orchestrating invadopodium assembly and extracellular matrix (ECM) degradation. Ca(2+) oscillation signals facilitate invadopodial precursor assembly by activating Src. Disruption of Ca(2+) oscillations inhibited invadopodium assembly. Furthermore, STIM1 and Orai1 regulate the proteolysis activity of individual invadopodia. Mechanistically, Orai1 blockade inhibited the recycling of MT1-matrix metalloproteinase (MMP) to the plasma membrane and entrapped MT1-MMP in the endocytic compartment to inhibit ECM degradation. STIM1 knockdown significantly inhibited melanoma lung metastasis in a xenograft mouse model, implicating the importance of this pathway in metastatic dissemination. Our findings provide a novel mechanism for Ca(2+)-mediated cancer cell invasion and shed new light on the spatiotemporal organization of store-operated Ca(2+) signals during melanoma invasion and metastasis.
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T-bet Is Critical for the Development of Acute Graft-versus-Host Disease through Controlling T Cell Differentiation and Function.
J. Immunol.
PUBLISHED: 11-19-2014
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T-bet is a master regulator for IFN-? production and Th1 differentiation. We evaluated the roles of T-bet and IFN-? in T cell responses in acute graft-versus-host disease (GVHD) and found that T-bet(-/-) T cells induced significantly less GVHD compared with wild-type or IFN-?(-/-) counterparts in both MHC-mismatched and MHC-matched but minor histocompatibility Ag-mismatched models driven by CD4 T cells. T-bet(-/-), but not IFN-?(-/-), CD4 T cells had a markedly reduced ability to cause tissue damage in liver and gut. This distinct outcome is reflected by the differential gene expression on donor CD4 T cells deficient for T-bet or IFN-?. At mRNA and protein levels, we defined several T-bet-dependent molecules that may account for the impaired ability of T-bet(-/-) T cells to migrate into target organs and to produce Th1-related cytokines. Moreover, these molecules were independent of either endogenous IFN-?, such as CXCR3 and programmed death-1, or systematic IFN-?, such as NKG2D, I-A(b), and granzyme B. Although both T-bet(-/-) and IFN-?(-/-) CD4 T cells are prone to differentiate into Th17 cells, polarized Th17 cells deficient for T-bet but not for IFN-? had a significantly reduced ability to cause GVHD. Finally, T-bet(-/-) T cells had a compromised graft-versus-leukemia effect, which could be essentially reversed by neutralization of IL-17 in the recipients. We conclude that T-bet is required for Th1 differentiation and migration, as well as for optimal function of Th17 cells. Thus, targeting T-bet or regulating its downstream effectors independent of IFN-? may be a promising strategy to control GVHD in the clinic.
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Plastid-LCGbase: a collection of evolutionarily conserved plastid-associated gene pairs.
Nucleic Acids Res.
PUBLISHED: 11-08-2014
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Plastids carry their own genetic material that encodes a variable set of genes that are limited in number but functionally important. Aside from orthology, the lineage-specific order and orientation of these genes are also relevant. Here, we develop a database, Plastid-LCGbase (http://lcgbase.big.ac.cn/plastid-LCGbase/), which focuses on organizational variability of plastid genes and genomes from diverse taxonomic groups. The current Plastid-LCGbase contains information from 470 plastid genomes and exhibits several unique features. First, through a genome-overview page generated from OrganellarGenomeDRAW, it displays general arrangement of all plastid genes (circular or linear). Second, it shows patterns and modes of all paired plastid genes and their physical distances across user-defined lineages, which are facilitated by a step-wise stratification of taxonomic groups. Third, it divides the paired genes into three categories (co-directionally-paired genes or CDPGs, convergently-paired genes or CPGs and divergently-paired genes or DPGs) and three patterns (separation, overlap and inclusion) and provides basic statistics for each species. Fourth, the gene pairing scheme is expandable, where neighboring genes can also be included in species-/lineage-specific comparisons. We hope that Plastid-LCGbase facilitates gene variation (insertion-deletion, translocation and rearrangement) and transcription-level studies of plastid genomes.
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A multiscale approach to the adsorption of core-shell nanoparticles at fluid interfaces.
Soft Matter
PUBLISHED: 11-06-2014
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Self-assembly of colloidal particles at liquid-liquid interfaces is a process with great potential for the creation of controlled structures, due to the trapping of the particles in the plane of the interface combined with their lateral mobility. Here we present a multiscale characterisation of the adsorption and interfacial behaviour of core-shell iron oxide-poly(ethylene glycol) nanoparticles at a water-n-decane interface using three complementary, in situ, methods, which span many different length scales. First, dynamic interfacial measurements are taken to follow the adsorption of particles from the bulk aqueous phase to the interface. The mechanical properties of the interface are then probed using micron-sized tracers in probe-particle tracking and nano-tracers in fluorescence correlation spectroscopy. The results show that the rate of particle adsorption to the interface scales with the square of bulk concentration, as predicted by a recent model. In addition, we show that despite full monolayers of nanoparticles forming, the interface remains unexpectedly fluid, with only a slowing of tracer particle mobility but no evidence of interface jamming as seen for hard nanoparticles. Our results illustrate that nanoparticles stabilised by soft, extended polymeric shells, display distinct features at fluid interfaces that can be harnessed for the fabrication of functional materials.
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Effects of azimuthal angles on laser interference lithography.
Appl Opt
PUBLISHED: 10-17-2014
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This paper discusses the effects of azimuthal angles on two-, three-, and four-beam laser interference. In two- or three-beam laser interference, periodic surface structures of lines or dots were obtained. In four-beam laser interference with the polarization mode of TE-TM-TE-TM, the modulation in a particular direction was formed and calculated. In the work, a He-Ne laser system was used to simulate two-, three-, and four-beam laser interference, and the interference pattern was detected by a CCD. A high-power Nd:YAG laser interference lithography system was set up to pattern silicon wafers. In the experiments, one azimuthal angle was changed every time to form interference patterns when polarization states were fixed and incident angles were equal. The experimental results have shown that the azimuthal angle affects the periods and feature sizes of the interference patterns and the fabricated surface structures, which are in accordance with the theoretical and computer simulation results.
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Presence of qnr, aac(6')-Ib, qepA, oqxAB, and mutations in gyrase and topoisomerase in nalidixic acid-resistant Salmonella isolates recovered from retail chicken carcasses.
Foodborne Pathog. Dis.
PUBLISHED: 09-05-2014
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Four hundred sixty-two nalidixic acid- and/or ciprofloxacin-resistant Salmonella isolates were examined for presence of quinolone-resistance mechanisms. A total of 339 amino acid substitutions were identified in GyrA (204) and ParC (135). Ser83Phe/Asp87Gly (29.4%) were most commonly detected in GyrA in 136 isolates, and to a lesser extent of Asp87Asn (22.8%), Asp87Gly (19.1%), Ser83Phe/Asp87Asn (19.1%), and Ser83Tyr (5.1%). Ser80Arg (97.0%) was detected in ParC in 132 isolates. Simultaneous mutations in GyrA and ParC (n=109) were commonly detected to be Ser83Phe/Asp87Gly(GyrA)-Ser80Arg(ParC) (35.8%), Asp87Asn(GyrA)-Ser80Arg(ParC) (22.9%), and Ser83Phe/Asp87Asn(GyrA)-Ser80Arg(ParC) (21.1%). qnrA, qnrB, qnrS, aac(6')-Ib, qepA, and oqxAB were detected in 52 (11.3%), 64 (13.9%), 11(2.4%), 107 (23.2%), 6 (1.3%), and 194 (42.0%) of 462 isolates, respectively. Isolates carried more qnr, aac(6')-Ib, qepA, and oqxAB genes, and amino acid substitution in GyrA and ParC was more resistant to nalidixic acid and fluoroquinolones.
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Hierarchical Supramolecular Assembly of Sterically Demanding ?-Systems by Conjugation with Oligoprolines.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 08-15-2014
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Self-assembly from flexible worm-like threads via bundles of rigid fibers to nanosheets and nanotubes was achieved by covalent conjugation of perylene monoimide (PMI) chromophores with oligoprolines of increasing length. Whereas the chromophoric ?-system and the peptidic building block do not self-aggregate, the covalent conjugates furnish well-ordered supramolecular structures with a common wall/fiber thickness. Their morphology is controlled by the number of repeat units and can be tuned by seemingly subtle structural modifications.
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Suppression of degradation induced by negative gate bias and illumination stress in amorphous InGaZnO thin-film transistors by applying negative drain bias.
ACS Appl Mater Interfaces
PUBLISHED: 04-10-2014
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The effect of drain bias (V(DS)) on the negative gate bias and illumination stress (NBIS) stability of amorphous InGaZnO (a-IGZO) thin-film transistors was investigated using a double-sweeping gate voltage (V(GS)) mode. The variation in the transfer characteristics was explored using current-voltage and capacitance-voltage characteristics. In the initial stage (<1000 s) of NBIS with grounded V(DS) (V(GS) = -40 V and V(DS) = 0 V), the transfer characteristics shifted negatively with an insignificant change in the subthreshold swing (SS) because of hole trapping at an IGZO/gate insulator interface. On the other hand, on-current degradation was observed and was accelerated in the forward measurement as the NBIS duration increased. The results indicated that NBIS induced donor-like defects near the conduction band; however, the transfer curves in the reverse measurement shifted positively without on-current and SS degradations. It was found that the degradations were enhanced by applying a positive V(DS) bias (V(GS) = -40 V and V(DS) = 40 V); in contrast, they could be reduced by applying a small negative V(DS) of V(DS) > V(GS) (V(GS) = -40 V and V(DS) = -20 V). Furthermore, it was confirmed that the NBIS degradations could be suppressed by applying a large negative V(DS) bias of V(DS) < V(GS) (V(GS) = -40 V and V(DS) = -60 V) during NBIS.
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Characterization of extended-spectrum beta-lactamases-producing Salmonella strains isolated from retail foods in Shaanxi and Henan Province, China.
Food Microbiol.
PUBLISHED: 02-03-2014
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Extended-spectrum beta-lactamases (ESBL)-producing Salmonella enterica have been reported worldwide. However, research on foodborne ESBL-producing Salmonella has been rarely conducted. One hundred and thirty eight ceftriaxone or/and cefoperazone-resistant Salmonella strains recovered from retail foods in Shaanxi and Henan Province, China, were screened for ESBL. The ESBL-producing strains were further characterized for antimicrobial resistance, pulse field gel electrophoresis (PFGE) profiles, and the presence of blaTEM, blaSHV, blaOXA, blaCTX-M, and blaPSE. The transferability of ESBL encoding genes to a susceptible Escherichia coli strain was also investigated. Thirty (21.7%) isolates were identified as ESBL positive and belonged to S. enterica serovars Indiana, Shubra, Typhimurium, and Enteritidis. S. Indiana and S. Shubra isolates were firstly identified in ESBL-producing strains. Great genetic diversity was seen among these ESBL-producing strains. Nucleotide sequence analysis revealed that blaTEM-1B was the only ESBL-encoding gene among the genes tested and was detected in 26 of 30 strains and was carried in the conjugative plasmids. The blaTEM-1B gene was transferable through conjugation at rates ranging from 4.71 × 10(-7) to 7.55 × 10(-6) transconjugant per recipient cell. This study provides the evidence of foodborne ESBL-producing Salmonella, and the transferability of plasmid harboring ESBL-encoding genes could possibly contribute to the dissemination of ESBL.
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New in situ capture quantitative (real-time) reverse transcription-PCR method as an alternative approach for determining inactivation of Tulane virus.
Appl. Environ. Microbiol.
PUBLISHED: 01-24-2014
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Human noroviruses (HuNoVs) are the major cause of epidemic nonbacterial gastroenteritis. Although quantitative (real-time) reverse transcription-PCR (qRT-PCR) is widely used for detecting HuNoVs, it only detects the presence of viral RNA and does not indicate viral infectivity. Human blood group antigens (HBGAs) have been identified as receptors/co-receptors for both HuNoVs and Tulane virus (TV) and are crucial for viral infection. We propose that viral infectivity can be evaluated with a molecular assay based on receptor-captured viruses. In this study, we employed TV as an HuNoV surrogate to validate the HBGA-based capture qRT-PCR method against the 50% tissue culture infectious dose (TCID50) method. We employed type B HBGA on an immuno-well module to concentrate TV, followed by amplification of the captured viral genome by in situ qRT-PCR. We first demonstrated that this in situ capture qRT-PCR (ISC-qRT-PCR) method could effectively concentrate and detect TV. We then treated TV under either partial or full inactivation conditions and measured the remaining infectivity by ISC-qRT-PCR and a tissue culture-based amplification method (TCID50). We found that the ISC-qRT-PCR method could be used to evaluate virus inactivation deriving from damage to the capsid and study interactions between the capsid and viral receptor. Heat, chlorine, and ethanol treatment primarily affect the capsid structure, which in turns affects the ability of the capsid to bind to viral receptors. Inactivation of the virus by these methods could be reflected by the ISC-qRT-PCR method and confirmed by TCID50 assay. However, the loss of the infectivity caused by damage to the viral genome (such as that from UV irradiation) could not be effectively reflected by this method. Despite this limitation, the ISC-qRT-PCR provides an alternative approach to determine inactivation of Tulane virus. A particular advantage of the ISC-qRT-PCR method is that it is also a faster and easier method to effectively recover and detect the viruses, as there is no need to extract viral RNA or to transfer the captured virus from magnetic beads to PCR tubes for further amplification. Therefore, ISC-qRT-PCR can be easily adapted for use in automated systems for multiple samples.
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Prevalence of Extended-Spectrum b-Lactamase-Producing Salmonella on Retail Chicken in Six Provinces and Two National Cities in the Peoples Republic of China.
J. Food Prot.
PUBLISHED: 12-03-2013
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Prevalence of extended-spectrum ?-lactamase (ESBL)-producing Salmonella in food is not well documented. This study investigated the prevalence of ESBL-producing Salmonella in 699 Salmonella isolates recovered from 1,152 retail chickens collected from six provinces and two national cities in the Peoples Republic of China in 2011. ESBL-producing isolates were screened by double-disk synergy test and confirmed using PCR and DNA sequencing. Of the 699 isolates tested, 60 (8.58%) were identified to be ESBL-producing Salmonella. Prevalence of ESBL-producing Salmonella was the highest in Shanghai city (17 [24.64%] of 69), followed by Shaanxi (10 [15.38%] of 65), Fujian (9 [11.69%] of 77), Guangdong (9 [7.69%] of 117), Sichuan (5 [7.25%] of 69), Beijing (6 [5.17%] of 116), Henan (4 [4.65%] of 86), and Guangxi (0 [0%] of 100) province. Significant difference (P < 0.05) in the prevalence of ESBL-producing Salmonella was found among six provinces and two cities. No significant difference (P > 0.05) in the prevalence was found between wet markets and supermarkets or between whole chickens and chopped chickens. The prevalence of ESBL-producing Salmonella differed significantly (P < 0.05) among different seasons, being higher in autumn than in spring and winter. Overall, ESBL-producing Salmonella varied significantly (P < 0.05) among 12 detected Salmonella serotypes: Abony (1 [33.33%] of 3), Indiana (28 [28.57%] of 98), Edinburg (6 [24.00%] of 25), Shubra (2 [20.00%] of 10), Uppsala (1 [16.67%] of 6), Thompson (8 [14.81%] of 54), Haardt (1 [12.50%] of 8), Agona (3 [9.68%] of 31), Gueuletapee (1 [6.25%] of 16), Typhimurium (4 [5.56%] of 72), Heidelberg (1 [4.55%] of 22), and Enteritidis (4 [3.17%] of 126). This study revealed that ESBL-producing Salmonella do exist in retail chicken in the Peoples Republic of China and that the potential risk of their presence in foods needs further exploration.
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Seasonal dynamics and diversity of bacteria in retail oyster tissues.
Int. J. Food Microbiol.
PUBLISHED: 10-14-2013
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Oysters are one of the important vehicles for the transfer of foodborne pathogens. It was reported that bacteria could be bio-accumulated mainly in the gills and digestive glands. In artificially treated oysters, bacterial communities have been investigated by culture-independent methods after harvest. However, little information is available on the seasonal dynamics of bacterial accumulation in retail oyster tissues. In this study, retail oysters were collected from local market in different seasons. The seasonal dynamics and diversity of bacteria in oyster tissues, including the gills, digestive glands and residual tissues, were analyzed by denaturing gradient gel electrophoresis (DGGE). It was interesting that the highest bacterial diversity appeared in the Fall season, not in summer. Our results indicated that Proteobacteria was the predominant member (23/46) in oyster tissues. Our results also suggested that bacterial diversity in gills was higher than that in digestive glands and other tissues. In addition, not all the bacteria collected from surrounding water by gills were transferred to digestive glands. On the other hand, few bacteria were found in oyster tissues except in the gills. Therefore, the gills could be the best candidate target tissue for monitoring of pathogenic bacteria either to human or to oyster.
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Inactivation conditions for human norovirus measured by an in situ capture-qRT-PCR method.
Int. J. Food Microbiol.
PUBLISHED: 09-17-2013
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Human norovirus (HuNoV) is a leading cause of foodborne gastroenteritis. Unfortunately, the inactivation parameters for HuNoV in clinical, food and environmental samples have not been established. Due to the inability to cultivate HuNoV in vitro, quantitative real-time RT-PCR (qRT-PCR) is widely-used for detecting HuNoVs. However, qRT-PCR does not indicate viral infectivity. Our method employs histo-blood group antigens (HBGAs) as viral receptors/co-receptors and container-affixed capture agents to concentrate HuNoVs. The captured viruses are denatured and its genome is amplified in the same module by in situ capture qRT-PCR (ISC-qRT-PCR). Greater than three log10 reduction in the receptor-captured viral genomic signal (RCVGS) was observed when HuNoV was treated by heat at 72°C for 4min, by chlorine at a final concentration of 16ppm in less than 1min, and by UV irradiation at 1J/cm(2). Treatment of low-titer HuNoV (<10(3) copies/sample) with 70% ethanol for 20s reduced the RCVGS of HuNoV by two log10. However, ethanol had a limited effect on high-titer samples of HuNoV (>10(3) copies/sample). The results demonstrate that ISC-qRT-PCR method could be used as an alternative method to measure encapsidated viral RNA and indirectly indicate the inactivation status of HuNoV caused by physical treatment such as heat, and chemical treatment such as chlorine, that damage the ability of the virus to bind to its receptor.
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Pharmacologic inhibition of PKC? and PKC? prevents GVHD while preserving GVL activity in mice.
Blood
PUBLISHED: 08-01-2013
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Allogeneic hematopoietic cell transplantation (HCT) is the most effective therapy for hematopoietic malignancies through T-cell-mediated graft-vs-leukemia (GVL) effects but often leads to severe graft-vs-host disease (GVHD). Given that protein kinase C? (PKC?), in cooperation with PKC?, is essential for T-cell signaling and function, we have evaluated PKC? and PKC? as potential therapeutic targets in allogeneic HCT using genetic and pharmacologic approaches. We found that the ability of PKC?(-/-)/?(-/-) donor T cells to induce GVHD was further reduced compared with PKC?(-/-) T cells in relation with the relevance of both isoforms to allogeneic donor T-cell proliferation, cytokine production, and migration to GVHD target organs. Treatment with a specific inhibitor for both PKC? and PKC? impaired donor T-cell proliferation, migration, and chemokine/cytokine production and significantly decreased GVHD in myeloablative preclinical murine models of allogeneic HCT. Moreover, pharmacologic inhibition of PKC? and PKC? spared T-cell cytotoxic function and GVL effects. Our findings indicate that PKC? and ? contribute to T-cell activation with overlapping functions essential for GVHD induction while less critical to the GVL effect. Thus, targeting PKC? and PKC? signaling with pharmacologic inhibitors presents a therapeutic option for GVHD prevention while largely preserving the GVL activity in patients receiving HCT.
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Depth-aware image seam carving.
IEEE Trans Cybern
PUBLISHED: 07-22-2013
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Image seam carving algorithm should preserve important and salient objects as much as possible when changing the image size, while not removing the secondary objects in the scene. However, it is still difficult to determine the important and salient objects that avoid the distortion of these objects after resizing the input image. In this paper, we develop a novel depth-aware single image seam carving approach by taking advantage of the modern depth cameras such as the Kinect sensor, which captures the RGB color image and its corresponding depth map simultaneously. By considering both the depth information and the just noticeable difference (JND) model, we develop an efficient JND-based significant computation approach using the multiscale graph cut based energy optimization. Our method achieves the better seam carving performance by cutting the near objects less seams while removing distant objects more seams. To the best of our knowledge, our algorithm is the first work to use the true depth map captured by Kinect depth camera for single image seam carving. The experimental results demonstrate that the proposed approach produces better seam carving results than previous content-aware seam carving methods.
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Fluorescence correlation spectroscopy of repulsive systems: theory, simulation, and experiment.
J Chem Phys
PUBLISHED: 06-14-2013
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The theoretical basis of fluorescence correlation spectroscopy (FCS) for repulsive systems, such as charged colloids or macromolecules, has been further expanded and developed. It is established that the collective correlation function can no longer be fitted using the theoretical model of non-interacting systems. Also, it is discovered that the collective correlation function can be divided into two parts: a self-part and a distinct-part, named as the self-correlation and cross-correlation function, respectively. The former indicates the self-diffusion of objects, while the latter describes mutual interactions. Dual-color fluorescence cross-correlation spectroscopy provides the direct measurements of the two parts. The particle concentration and mean squared displacement of single particles can be deduced from the self-correlation function, while the correlation volume between particles can be approximated from the cross-correlation function. In the case of charged colloids, the Debye length of the solution and particle surface charge number can be fitted from the cross-correlation function. These theoretical results are successfully proven using Brownian dynamics simulations and preliminary FCS experiments for model charged colloidal systems.
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A rapid method for the detection of foodborne pathogens by extraction of a trace amount of DNA from raw milk based on amino-modified silica-coated magnetic nanoparticles and polymerase chain reaction.
Anal. Chim. Acta
PUBLISHED: 05-20-2013
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A method based on amino-modified silica-coated magnetic nanoparticles (ASMNPs) and polymerase chain reaction (PCR) was developed to rapidly and sensitively detect foodborne pathogens in raw milk. After optimizing parameters such as pH, temperature, and time, a trace amount of genomic DNA of pathogens could be extracted directly from complex matrices such as raw milk using ASMNPs. The magnetically separated complexes of genomic DNA and ASMNPs were directly subjected to single PCR (S-PCR) or multiplex PCR (M-PCR) to detect single or multiple pathogens from raw milk samples. Salmonella Enteritidis (Gram-negative) and Listeria monocytogenes (Gram-positive) were used as model organisms to artificially contaminate raw milk samples. After magnetic separation and S-PCR, the detection sensitivities were 8 CFU mL(-1) and 13 CFU mL(-1) respectively for these two types of pathogens. Furthermore, this method was successfully used to detect multiple pathogens (S. Enteritidis and L. monocytogenes) from artificially contaminated raw milk using M-PCR at sensitivities of 15 CFU mL(-1) and 25 CFU mL(-1), respectively. This method has great potential to rapidly and sensitively detect pathogens in raw milk or other complex food matrices.
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c-Rel is an essential transcription factor for the development of acute graft-versus-host disease in mice.
Eur. J. Immunol.
PUBLISHED: 04-12-2013
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Transcription factors of the Rel/NF-?B family are known to play different roles in immunity and inflammation, although the putative role of c-Rel in transplant tolerance and graft-versus-host disease (GVHD) remains elusive. We report here that T cells deficient for c-Rel have a dramatically reduced ability to cause acute GVHD after allogeneic bone marrow transplantation using major and minor histocompatibility mismatched murine models. In the study to understand the underlying mechanisms, we found that c-Rel(-/-) T cells had a reduced ability to expand in lymphoid organs and to infiltrate in GVHD target organs in allogeneic recipients. c-Rel(-/-) T cells were defective in the differentiation into Th1 cells after encountering alloantigens, but were enhanced in the differentiation toward Foxp3(+) regulatory T (Treg) cells. Furthermore, c-Rel(-/-) T cells had largely preserved activity to mediate graft-versus-leukemia response. Taken together, our findings indicate that c-Rel plays an essential role in T cells in the induction of acute GVHD, and suggest that c-Rel can be a potential target for therapeutic intervention in allogeneic hematopoietic cell transplantation in the clinic.
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2-Ureido-4-pyrimidone-based hydrogels with multiple responses.
Chemphyschem
PUBLISHED: 04-11-2013
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Functionalisation of poly[2-(dimethylamino)ethyl methacrylate] (a responsive methacrylate) with light-activatable 2-ureido-4-pyrimidone units allows a supramolecular hydrogel to be obtained that combines temperature, light and pH response with self-healing properties. Whereas the self-healing properties of this system were described previously, this report focuses on its response to different external stimuli, which is studied by quartz crystal microbalance analysis of thin films of the material. Reversible collapse with increasing temperature, reversible swelling with decreasing pH and irreversible shrinkage with UV exposure are demonstrated. These three stimuli are combined to have externally gated or tuned responses. Thermo-induced swelling and shrinkage can be reversibly inhibited by changing the pH and irreversibly regulated by exposure to light of different doses. These materials represent the first general strategy to obtain responsive self-healing hydrogels in which the response and the self-healing properties are decoupled from each other and can be tuned independently.
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Distinct genomic aberrations between low-grade and high-grade gliomas of Chinese patients.
PLoS ONE
PUBLISHED: 01-17-2013
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Glioma is a type of tumor that develops in the central nerve system, mainly the brain. Alterations of genomic sequence and sequence segments (such as copy number variations or CNV and copy neutral loss of heterozygosities or cnLOH) are thought to be a major determinant of the tumor grade.
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Dynamic change and impact of myeloid-derived suppressor cells in allogeneic bone marrow transplantation in mice.
Biol. Blood Marrow Transplant.
PUBLISHED: 01-15-2013
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Myeloid-derived suppressor cells (MDSCs) are a group of myeloid cells composed of hematopoietic progenitor cells, immature macrophages, dendritic cells, and granulocytes, which accumulate in inflammatory diseases and various cancers. Here, we investigated the dynamic changes and effects of MDSCs in graft-versus-host disease (GVHD) development and/or tumor relapse after syngeneic and allogeneic bone marrow transplantation (BMT). We found that adding functional MDSCs in donor graft alleviated GVHD, whereas removal of MDSCs in vivo exacerbated GVHD. After T cell-deplete BMT, MDSCs transiently accumulated in the blood and spleen of recipients without GVHD. In contrast, after T cell-replete BMT, the levels of blood MDSCs were constantly elevated in recipients with GVHD. MDSC accumulation positively correlated with the severity of GVHD. Additionally, MDSC accumulation was further increased upon tumor relapse. Although MDSCs isolated from both syngeneic and allogeneic BMT recipients inhibited T cell proliferation in response to alloantigen stimulation ex vivo, MDSCs from the recipients with GVHD showed much higher suppressive potency compared with those from recipients without GVHD. These results indicate that MDSCs can regulate the immune response in acute GVHD, and possibly tumor relapse, subsequent to allogeneic BMT.
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Adoptive transfer of Tc1 or Tc17 cells elicits antitumor immunity against established melanoma through distinct mechanisms.
J. Immunol.
PUBLISHED: 01-11-2013
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Adoptive cell transfer (ACT) of ex vivo-activated autologous tumor-reactive T cells is currently one of the most promising approaches for cancer immunotherapy. Recent studies provided some evidence that IL-17-producing CD8(+) (Tc17) cells may exhibit potent antitumor activity, but the specific mechanisms have not been completely defined. In this study, we used a murine melanoma lung-metastasis model and tested the therapeutic effects of gp100-specific polarized type I CD8(+) cytotoxic T (Tc1) or Tc17 cells combined with autologous bone marrow transplantation after total body irradiation. Bone marrow transplantation combined with ACT of antitumor (gp100-specific) Tc17 cells significantly suppressed the growth of established melanoma, whereas Tc1 cells induced long-term tumor regression. After ACT, Tc1 cells maintained their phenotype to produce IFN-?, but not IL-17. However, although Tc17 cells largely preserved their ability to produce IL-17, a subset secreted IFN-? or both IFN-? and IL-17, indicating the plasticity of Tc17 cells in vivo. Furthermore, after ACT, the Tc17 cells had a long-lived effector T cell phenotype (CD127(hi)/KLRG-1(low)) as compared with Tc1 cells. Mechanistically, Tc1 cells mediated antitumor immunity primarily through the direct effect of IFN-? on tumor cells. In contrast, despite the fact that some Tc17 cells also secreted IFN-?, Tc17-mediated antitumor immunity was independent of the direct effects of IFN-? on the tumor. Nevertheless, IFN-? played a critical role by creating a microenvironment that promoted Tc17-mediated antitumor activity. Taken together, these studies demonstrate that both Tc1 and Tc17 cells can mediate effective antitumor immunity through distinct effector mechanisms, but Tc1 cells are superior to Tc17 cells in mediating tumor regression.
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Inhibition of TGF-?1-receptor posttranslational core fucosylation attenuates rat renal interstitial fibrosis.
Kidney Int.
PUBLISHED: 01-10-2013
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The profibrotic cytokine transforming growth factor-?1 (TGF-?1) causes renal fibrosis by binding to receptors at the cell surface; however, it is not clear which of the TGF-? superfamily receptors correlates with renal fibrosis. To resolve this, we quantified TGF-? superfamily receptor expression in the kidneys of rats with unilateral ureteral obstruction using a real-time PCR gene array. Expression of activin receptor-like kinase (ALK)-5, ALK7, and TGF-? receptor II (TGF-?RII) mRNA increased significantly, while ALK6 mRNA expression was significantly decreased in the obstructed rat kidney. Core fucosylation is essential for the proper function of both TGF-?RII and ALK5 in cultured human renal proximal tubular epithelial cells in vitro. Therefore, we targeted posttranslational core fucosylation, regulated by ?-1,6 fucosyltransferase (FUT8), by adenoviral-mediated knockdown of FUT8 mRNA in vivo and measured TGF-?RII and ALK5 expression and the progression of renal fibrosis. Despite long-term obstruction injury, inhibition of TGF-?RII and ALK5 of core fucosylation ameliorated the progression of renal fibrosis, an effect independent of TGF-?RII and ALK5 expression. Thus, the regulation of TGF-?1-receptor core fucosylation may provide a novel potential therapeutic strategy for treating renal fibrosis.
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Layer with reduced viscosity at water-oil interfaces probed by fluorescence correlation spectroscopy.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 01-03-2013
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The two-dimensional diffusion of isolated molecular tracers at the water-n-alkane interface was studied with fluorescence correlation spectroscopy. The interfacial diffusion coefficients of larger tracers with a hydrodynamic radius of 4.0 nm agreed well with the values calculated from the macroscopic viscosities of the two bulk phases. However, for small molecule tracers with hydrodynamic radii of only 1.0 and 0.6 nm, notable deviations were observed, indicating the existence of an interfacial region with reduced effective viscosity and increased mobility.
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Functional Networking of Human Divergently Paired Genes (DPGs).
PLoS ONE
PUBLISHED: 01-01-2013
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Divergently paired genes (DPGs), also known as bidirectional (head-to-head positioned) genes, are conserved across species and lineages, and thus deemed to be exceptional in genomic organization and functional regulation. Despite previous investigations on the features of their conservation and gene organization, the functional relationship among DPGs in a given species and lineage has not been thoroughly clarified. Here we report a network-based comprehensive analysis on human DPGs and our results indicate that the two members of the DPGs tend to participate in different biological processes while enforcing related functions as modules. Comparing to randomly paired genes as a control, the DPG pairs have a tendency to be clustered in similar "cellular components" and involved in similar "molecular functions". The functional network bridged by DPGs consists of three major modules. The largest module includes many house-keeping genes involved in core cellular activities. This module also shows low variation in expression in both CNS (central nervous system) and non-CNS tissues. Based on analyses of disease transcriptome data, we further suggest that this particular module may play crucial roles in HIV infection and its disease mechanism.
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LCGbase: A Comprehensive Database for Lineage-Based Co-regulated Genes.
Evol. Bioinform. Online
PUBLISHED: 12-13-2011
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Animal genes of different lineages, such as vertebrates and arthropods, are well-organized and blended into dynamic chromosomal structures that represent a primary regulatory mechanism for body development and cellular differentiation. The majority of genes in a genome are actually clustered, which are evolutionarily stable to different extents and biologically meaningful when evaluated among genomes within and across lineages. Until now, many questions concerning gene organization, such as what is the minimal number of genes in a cluster and what is the driving force leading to gene co-regulation, remain to be addressed. Here, we provide a user-friendly database-LCGbase (a comprehensive database for lineage-based co-regulated genes)-hosting information on evolutionary dynamics of gene clustering and ordering within animal kingdoms in two different lineages: vertebrates and arthropods. The database is constructed on a web-based Linux-Apache-MySQL-PHP framework and effective interactive user-inquiry service. Compared to other gene annotation databases with similar purposes, our database has three comprehensible advantages. First, our database is inclusive, including all high-quality genome assemblies of vertebrates and representative arthropod species. Second, it is human-centric since we map all gene clusters from other genomes in an order of lineage-ranks (such as primates, mammals, warm-blooded, and reptiles) onto human genome and start the database from well-defined gene pairs (a minimal cluster where the two adjacent genes are oriented as co-directional, convergent, and divergent pairs) to large gene clusters. Furthermore, users can search for any adjacent genes and their detailed annotations. Third, the database provides flexible parameter definitions, such as the distance of transcription start sites between two adjacent genes, which is extendable to genes that flanking the cluster across species. We also provide useful tools for sequence alignment, gene ontology (GO) annotation, promoter identification, gene expression (co-expression), and evolutionary analysis. This database not only provides a way to define lineage-specific and species-specific gene clusters but also facilitates future studies on gene co-regulation, epigenetic control of gene expression (DNA methylation and histone marks), and chromosomal structures in a context of gene clusters and species evolution. LCGbase is freely available at http://lcgbase.big.ac.cn/LCGbase.
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Phase behavior of poly(sulfobetaine methacrylate)-grafted silica nanoparticles and their stability in protein solutions.
Langmuir
PUBLISHED: 11-29-2011
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Biocompatible and zwitterionic poly(sulfobetaine methacrylate) (PSBMA) was grafted onto the surface of initiator-modified silica nanoparticles via surface-initiated atom transfer radical polymerization. The resultant samples were characterized via nuclear magnetic resonance, Fourier transform infrared spectroscopy, transmission electron microscopy, and thermogravimetric analysis. Their molecular weights and molecular weight distributions were determined via gel permeation chromatography after the removal of silica by etching. Moreover, the phase behavior of these polyzwitterionic-grafted silica nanoparticles in aqueous solutions and stability in protein/PBS solutions were systematically investigated. Dynamic light scattering and UV-visible spectroscopy results indicate that the silica-g-PSBMA nanoparticles exhibit an upper critical solution temperature (UCST) in aqueous solutions, which can be controlled by varying the PSBMA molecular weight, ionic strength, silica-g-PSBMA nanoparticle concentration, and solvent polarity. The UCSTs shift toward high temperatures with increasing PSBMA molecular weight and silica-g-PSBMA nanoparticle concentration. However, increasing the ionic strength and solvent polarity leads to a lowering of the UCSTs. The silica-g-PSBMA nanoparticles are stable for at least 72 h in both negative and positive protein/PBS solutions at 37 °C. The current study is crucial for the translation of polyzwitterionic solution behavior to surfaces to exploit their diverse properties in the development of new, smart, and responsive coatings.
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Molecular typing of Vibrio parahaemolyticus isolates from the middle-east coastline of China.
Int. J. Food Microbiol.
PUBLISHED: 11-28-2011
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The occurrence of outbreaks of Vibrio parahaemolyticus gastroenteritis in China highlights the need for strain characterization and subtyping of this pathogenic species. A total of 56 epidemiologically-unrelated strains of V. parahaemolyticus were isolated from clinical samples, seafood and various environmental sites in the middle-east coastline of China from 2006 to 2008. The isolates were characterized using four molecular typing methods, including ribotyping, enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR), pulsed-field gel electrophoresis (PFGE), and sequence analysis of the gyrB gene. Genetic profiles of cluster analysis from these molecular typing tests clearly showed that there were differences in potential pathogenicity among isolates from seafood and its environments. Genetic characterization of two isolates (F13 and QS2) that originated from seafood demonstrated that they were potentially pathogenic. Discriminatory indices of four typing methods for the 56 V. parahaemolyticus isolates were differentiated by Simpsons Index of Diversity. The discriminatory index of ERIC-PCR typing was maximal (D=0.942), while that of sequence analysis of the gyrB gene was minimal (D=0.702). The discriminatory ability was greatly enhanced (D=0.966) when ERIC-PCR was coupled with sequence analysis of the gyrB gene. These results suggest that ERIC-PCR combined with sequence analysis of gyrB gene may be a reliable, rapid typing strategy for V. parahaemolyticus strains.
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Probing diffusion of single nanoparticles at water-oil interfaces.
Small
PUBLISHED: 09-02-2011
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The diffusion of nanoparticles at a water-alkane interface is studied using fluorescence correlation spectroscopy. Hydrophilic and hydrophobic quantum dots of 5, 8, and 11 nm radius are used. A slow-down of nanoparticle diffusion at the liquid-liquid interface is observed. The effect is most evident when the viscosities of both liquid phases are similar, here, at the water-decane interface. In this case, the interfacial diffusion coefficients of the hydrophilic particles are 1.5 times and those of the hydrophobic particles 2 times lower than the corresponding bulk values.
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Prevention of GVHD while sparing GVL effect by targeting Th1 and Th17 transcription factor T-bet and ROR?t in mice.
Blood
PUBLISHED: 08-19-2011
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Allogeneic hematopoietic cell transplantation (HCT) is effective therapy for hematologic malignancies through T cell-mediated GVL effects. However, HCT benefits are frequently offset by the destructive GVHD, which is also induced by donor T cells. Naive Th can differentiate into Th1 and Th17 subsets and both can mediate GVHD after adoptive transfer into an allogeneic host. Here we tested the hypothesis that blockade of Th1 and Th17 differentiation is required to prevent GVHD in mice. T cells with combined targeted disruption of T-bet and ROR?t have defective differentiation toward Th1 and Th17 and skewed differentiation toward Th2 and regulatory phenotypes, and caused ameliorated GVHD in a major MHC-mismatched model of HCT. GVL effects mediated by granzyme-positive CD8 T cells were largely preserved despite T-bet and ROR?t deficiency. These data indicate that GVHD can be prevented by targeting Th1 and Th17 transcription factors without offsetting GVL activity.
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Expression of B7-homolog 1 in Polymyositis.
Ann. Clin. Lab. Sci.
PUBLISHED: 08-17-2011
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Costimulatory molecules are increasingly recognized as crucial for stimulation and/ or inhibition of immune responses. The present study was undertaken to examine the expression and functional relevance of B7-homolog 1 (B7-H1) attributed significant immunoregulatory functions in polymyositis in vivo.
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A facile strategy for obtaining fresh Ag as SERS active substrates.
J Colloid Interface Sci
PUBLISHED: 07-07-2011
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A facile strategy has been reported to obtain on-line fresh Ag as surface-enhanced Raman scattering (SERS) active substrates by making AgCl nanoparticles exposed to the laser beam of Raman spectrometer. The composition and morphology of AgCl nanoparticles were characterized by X-ray diffraction (XRD), UV-visible (UV-vis) spectroscopy and scanning electron microscopy (SEM). The laser-driven evolvement and possible formation mechanism of cubic AgCl nanoparticles to Ag/AgCl composites were also investigated by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and high-resolution transmission electron microscopy (HRTEM). Raman measurements demonstrate that the fresh Ag nanoparticles with a few defects have a prominent SERS sensitivity to probe molecules, such as the 4-mercaptopyridine (4-Mpy) and 4-aminothiophenol (PATP) molecules. The SERS intensity of 4-Mpy and PATP increases up to the maximum when the laser irradiation time is prolonged to 50s, which corresponds to the defect extent and the proportion of fresh Ag in the Ag/AgCl composites. This work provides a simple, efficient and feasible approach for obtaining on-line fresh Ag as SERS substrates.
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A fluorescent, shape-persistent dendritic host with photoswitchable guest encapsulation and intramolecular energy transfer.
J. Am. Chem. Soc.
PUBLISHED: 07-01-2011
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A fluorescent and photoresponsive host based on rigid polyphenylene dendrimers (PPDs) has been synthesized. The key building block for the divergent dendrimer buildup is a complex tetracyclone 12 containing azobenzenyl, pyridyl, and ethynyl entities. The rigidity of polyphenylenes is of crucial importance for a site-specific placement of different functions: eight azobenzene (AB) moieties into the rigid scaffold, a fluorescent perylenetetracarboxdiimide (PDI) into the core, and eight pyridin functions into the interior cavities. AB moieties of host-1 undergo reversible cis-trans photoisomerization and are photostable, as confirmed by various techniques: UV-vis, (1)H NMR, size exclusion chromatography, and fluorescence correlation (FCS). In this system, AB moieties act as photoswitchable hinges and enable control over (i) molecular size, (ii) intramolecular energy transfer between AB and PDI, and (iii) encapsulation and release of guest molecules. The presence of PDI allows not only following the effect of cis-trans photoisomerization on molecular size with highly sensitive FCS but also monitoring the efficiency of the intramolecular energy transfer process (from AB to PDI) by time-resolved optical spectroscopy. Pyridyl functions were incorporated to facilitate guest uptake via hydrogen bonds between the host and guests. Also, we have demonstrated that the photoswitchability of the host can be utilized to actively encapsulate guest molecules into its interior cavities. This novel, light-driven encapsulation mechanism could enable the design of new drug delivery systems.
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Hypoxia-induced ?-catenin downregulation involves p53-dependent activation of Siah-1.
Cancer Sci.
PUBLISHED: 05-12-2011
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Solid tumors contain extensive hypoxic areas and it is of considerable importance to decipher the potential role of hypoxia in signaling pathway regulation. In the present study, we examined the impact of hypoxia on ?-catenin status and the mechanisms involved. Hypoxia significantly decreased ?-catenin protein, but had no effect on glycogen synthase kinase (GSK)-3? or adenomatous polyposis coli (APC) levels. However, hypoxia-induced ?-catenin downregulation seemed to require APC but not GSK-3?. Further investigation revealed that hypoxia significantly upregulated Siah-1, the human homolog of Drosophila seven in absentia. In addition, hypoxia augmented the interaction between ?-catenin and SIP and Skp1. Silencing of Siah-1, as well as the use of a dominant negative Siah-1 mutant, attenuated these responses to hypoxia and rescued ?-catenin transactivation. The Siah-1-mediated degradation of ?-catenin during hypoxia may involve p53, but not hypoxia-inducible factor-1, activation. Together, the results suggest that hypoxia downregulates ?-catenin by increasing Siah-1 expression in a p53-dependent manner.
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Nonsynonymous substitution rate (Ka) is a relatively consistent parameter for defining fast-evolving and slow-evolving protein-coding genes.
Biol. Direct
PUBLISHED: 02-22-2011
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Mammalian genome sequence data are being acquired in large quantities and at enormous speeds. We now have a tremendous opportunity to better understand which genes are the most variable or conserved, and what their particular functions and evolutionary dynamics are, through comparative genomics.
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Both size and GC-content of minimal introns are selected in human populations.
PLoS ONE
PUBLISHED: 02-16-2011
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We previously have studied the insertion and deletion polymorphism by sequencing no more than one hundred introns in a mixed human population and found that the minimal introns tended to maintain length at an optimal size. Here we analyzed re-sequenced 179 individual genomes (from African, European, and Asian populations) from the data released by the 1000 Genome Project to study the size dynamics of minimal introns.
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[Distribution and detection of pathogens in shellfish--a review].
Wei Sheng Wu Xue Bao
PUBLISHED: 02-01-2011
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Shellfish is one of important vehicles for dissemination of food-borne pathogens. The incidence of food-borne diseases increases every year. Therefore, monitoring and control on the food safety of shellfish is a significant public health concern worldwide. In recent years, our group has studied the pathogens in molecular detection, bioaccumulation and control in shellfish. Based on the our previous studies, the purpose of this article was to provide a review on the pathogens in shellfish in four aspects: the detection methods, distribution, depuration and epidemiology. The molecular methods were widely used in detection of pathogens in shellfish. In addition, the pathogens were bio-accumulated in the gills and digestive glands, including stomach and digestive diverticula, which are good candidate sites for detection of pathogens.
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Blocking core fucosylation of TGF-?1 receptors downregulates their functions and attenuates the epithelial-mesenchymal transition of renal tubular cells.
Am. J. Physiol. Renal Physiol.
PUBLISHED: 01-12-2011
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Posttranslational modification of proteins could regulate their multiple biological functions. Transforming growth factor-? receptor I and II (ALK5 and TGF-?RII), which are glycoproteins, play important roles in the renal tubular epithelial-mesenchymal transition (EMT). In the present study, we examined the role of core fucosylation of TGF-?RII and ALK5, which is regulated by ?-1,6 fucosyltransferase (Fut8), in the process of EMT of cultured human renal proximal tubular epithelial (HK-2) cells. The typical cell model of EMT induced by TGF-?1 was constructed to address the role of core fucosylation in EMT. Core fucosylation was found to be essential for both TGF-?RII and ALK5 to fulfill their functions, and blocking it with Fut8 small interfering RNA greatly reduced the phosphorylation of Smad2/3 protein, caused the inactivation of TGF-?/Smad2/3 signaling, and resulted in remission of EMT. More importantly, even with high levels of expressions of TGF-?1, TGF-?RII, and ALK5, blocking core fucosylation also could attenuate the EMT of HK-2 cells. Thus blocking core fucosylation of TGF-?RII and ALK5 may attenuate EMT independently of the expression of these proteins. This study may provide new insight into the role of glycosylation in renal interstitial fibrosis. Furthermore, core fucosylation may be a novel potential therapeutic target for treatment of renal tubular EMT.
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Efficient and selective prevention of GVHD by antigen-specific induced Tregs via linked-suppression in mice.
Biol. Blood Marrow Transplant.
PUBLISHED: 01-09-2011
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Naturally occurring regulatory T cells (nTregs) suppress the development of graft-versus-host disease (GVHD) and may spare graft-versus-leukemia (GVL) effect. Because nTreg is a rare population in a healthy individual, the limited source and the non-selective suppression are major hurdles towards the application of nTregs in the control of clinical GVHD after allogeneic hematopoietic cell transplantation (HCT). An alternative approach is to generate induced Tregs (iTregs) from naïve CD4 precursors, but the effectiveness of iTregs in the control of GVHD is highly controversial and requires further investigation. The other critical but unsolved issue in Treg therapy is how to achieve antigen (Ag)-specific tolerance that distinguishes GVHD and GVL effects. To address the important issues on the effectiveness of iTregs and Ag-specificity of Tregs, we generated Ag-specific iTregs and tested their potential in the prevention of GVHD in a pre-clinical bone marrow transplantation (BMT) model. CD4(+)CD25(+)Foxp3(+) iTregs generated from OT-II TCR transgenic T cells specific for OVA target Ag efficiently prevented GVHD induced by polyclonal T effector cells (Teffs) only in the allogeneic recipients that express OVA protein but not in OVA(-) recipients. The efficacy of these Ag-specific iTregs was significantly higher than polyclonal iTregs. As controls, OT-II CD4(+)Foxp3(-) cells had no effect on GVHD development in OVA(-) recipients and exacerbated GVHD in OVA(+) recipients when transplanted together with polyclonal Teffs. Because the iTregs recognize OVA whereas Teffs recognize alloAg bm12, our data reveal for the first time, to our knowledge, that Tregs prevent GVHD through a linked suppression. Mechanistically, OT-II iTregs expanded extensively, and significantly suppressed expansion and infiltration of Teffs in OVA(+) but not in OVA(-) recipients. These results demonstrate that Ag-specific iTregs can prevent GVHD efficiently and selectively, providing a proof of principle that Ag-specific iTregs may represent a promising cell therapy for their specificity and higher efficacy in allogeneic HCT.
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SMM-system: A mining tool to identify specific markers in Salmonella enterica.
J. Microbiol. Methods
PUBLISHED: 01-03-2011
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This report presents SMM-system, a software package that implements various personalized pre- and post-BLASTN tasks for mining specific markers of microbial pathogens. The main functionalities of SMM-system are summarized as follows: (i) converting multi-FASTA file, (ii) cutting interesting genomic sequence, (iii) automatic high-throughput BLASTN searches, and (iv) screening target sequences. The utility of SMM-system was demonstrated by using it to identify 214 Salmonella enterica-specific protein-coding sequences (CDSs). Eighteen primer pairs were designed based on eighteen S. enterica-specific CDSs, respectively. Seven of these primer pairs were validated with PCR assay, which showed 100% inclusivity for the 101 S. enterica genomes and 100% exclusivity of 30 non-S. enterica genomes. Three specific primer pairs were chosen to develop a multiplex PCR assay, which generated specific amplicons with a size of 180bp (SC1286), 238bp (SC1598) and 405bp (SC4361), respectively. This study demonstrates that SMM-system is a high-throughput specific marker generation tool that can be used to identify genus-, species-, serogroup- and even serovar-specific DNA sequences of microbial pathogens, which has a potential to be applied in food industries, diagnostics and taxonomic studies. SMM-system is freely available and can be downloaded from http://foodsafety.sjtu.edu.cn/SMM-system.html.
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[Circulating endothelial progenitor cell and its application].
Wei Sheng Yan Jiu
PUBLISHED: 11-02-2010
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Endothelial progenitor cells (EPCs) have the capacity to proliferate, migrate, and differentiate into mature vessel endothelial cells, but have not yet expressed into the mature vessel endothelial cell type, and have not formed to be the precursor cell of the blood vessels. For those EPCs existed in the peripheral blood circulation in human, known as circulating endothelial progenitor cells (CEPCs), participating in the vascular neogenesis after born and repairing process after endothelial injury. It has become a hot spot of the research on the cardiovascular diseases and other involving endothelial injury. This article comprehensively describes the bio-characteristics of EPCs, the factors influencing the number and functions of EPCs, and the newest research progress in the actual applications of EPCs, providing the new thoughts and new approach for the diagnosis and therapy of cardiovascular diseases.
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A general synthesis of high-quality inorganic nanocrystals via a two-phase method.
Small
PUBLISHED: 10-22-2010
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A two-phase method is exploited to prepare many kinds of nearly monodisperse, highly crystalline, size- and shape-controlled, surface-property-tunable inorganic nanocrystals, such as metal, semiconducting, magnetic, dielectric, and rare earth nanocrystals. The reaction of the two-phase system happens at the interface between the oil (nonpolar) and water (polar) phases and the interface is an exclusive site for both nucleation and growth. Interestingly, many solvent pairs with a clear interface can be applied to synthesize inorganic nanocrystals successfully. Generally, as-prepared nanocrystals with organic ligands are soluble in nonpolar solvents. Furthermore, exchange of ligands can also be realized readily and the final nanocrystals can be soluble in polar solvents. This two-phase method is a simple, reproducible, and general route and is becoming as powerful an approach as other solution-based synthetic approaches to high-quality inorganic nanocrystals.
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KaKs_Calculator 2.0: a toolkit incorporating gamma-series methods and sliding window strategies.
Genomics Proteomics Bioinformatics
PUBLISHED: 05-11-2010
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We present an integrated stand-alone software package named KaKs_Calculator 2.0 as an updated version. It incorporates 17 methods for the calculation of nonsynonymous and synonymous substitution rates; among them, we added our modified versions of several widely used methods as the gamma series including gamma-NG, gamma-LWL, gamma-MLWL, gamma-LPB, gamma-MLPB, gamma-YN and gamma-MYN, which have been demonstrated to perform better under certain conditions than their original forms and are not implemented in the previous version. The package is readily used for the identification of positively selected sites based on a sliding window across the sequences of interests in 5 to 3 direction of protein-coding sequences, and have improved the overall performance on sequence analysis for evolution studies. A toolbox, including C++ and Java source code and executable files on both Windows and Linux platforms together with a user instruction, is downloadable from the website for academic purpose at https://sourceforge.net/projects/kakscalculator2/.
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Species-specific PCR detection of the food-borne pathogen Vibrio parahaemolyticus using the irgB gene identified by comparative genomic analysis.
FEMS Microbiol. Lett.
PUBLISHED: 03-12-2010
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Vibrio parahaemolyticus is an enteric pathogen, which can cause acute gastroenteritis in humans after consumption of raw or partially cooked seafood, and specific molecular markers are necessary for its accurate identification by PCR methods. In the present study, 23 protein-coding sequences were identified by the comparative genomics method as V. parahaemolyticus-specific candidate markers. We targeted the irgB gene (vp2603), coding for iron-regulated virulence regulatory protein IrgB, in order to develop a PCR method for the detection of V. parahaemolyticus. PCR specificity was identified by amplification of 293 V. parahaemolyticus templates and by the loss of a PCR product with 11 strains from other Vibrio species and 35 non-Vibrio bacterial strains. The PCR assay had the 369-bp fragment and the sensitivity of 0.17 pg purified genomic DNA from V. parahaemolyticus. Furthermore, a multiplex PCR assay for the detection of total and virulent strains of V. parahaemolyticus was developed by targeting irgB, tdh and trh genes. These data indicated that the irgB gene is a new and effective marker for the detection of V. parahaemolyticus. In addition, this study demonstrates that genome sequence comparison has a powerful application in identifying specific markers for the detection and identification of bacterial pathogens.
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Therapeutic potential of human umbilical cord mesenchymal stem cells in the treatment of rheumatoid arthritis.
Arthritis Res. Ther.
PUBLISHED: 02-17-2010
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Rheumatoid arthritis (RA) is a T-cell-mediated systemic autoimmune disease, characterized by synovium inflammation and articular destruction. Bone marrow mesenchymal stem cells (MSCs) could be effective in the treatment of several autoimmune diseases. However, there has been thus far no report on umbilical cord (UC)-MSCs in the treatment of RA. Here, potential immunosuppressive effects of human UC-MSCs in RA were evaluated.
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A novel role for minimal introns: routing mRNAs to the cytosol.
PLoS ONE
PUBLISHED: 02-16-2010
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Introns and their splicing are tightly coupled with the subsequent mRNA maturation steps, especially nucleocytoplasmic export. A remarkable fraction of vertebrate introns have a minimal size of about 100 bp, while majority of introns expand to several kilobases even megabases in length.
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Identification of immune-relevant genes by expressed sequence tag analysis of head kidney from grass carp (Ctenopharyngodon idella).
Comp. Biochem. Physiol. Part D Genomics Proteomics
PUBLISHED: 02-11-2010
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Grass carp is the third largest aquaculture species in global production. However, genomic research of this species has been limited. To identify immune-related genes in grass carp, a normalized full-length cDNA library was constructed from head kidney tissues, and 6432 randomly selected clones were sequenced. 5289 high quality expressed sequence tags (EST) were generated and assembled into 2687 unigenes. Among them, 1585 unigenes showed significant similarity with known sequences in public databases, whereas the remaining 1102 unigenes appeared to be novel sequences with unknown functions. In particular, 136 immune-related genes were identified to encode immunoglobulins, FcRgamma, IFN-related proteins, various CD markers, MHCs, complements and other important immune-related factors; a majority of these genes are reported in grass carp for the first time. Sequence analysis indicated that grass carp has at least three subtypes of immunoglobulin light chains, namely L1, L2 and L3. Furthermore, FCRgamma was found to broadly express in different tissues. Our study constitutes the first EST analysis of lymphatic tissue in grass carp, and could pave the way for further research of immune-related genes and functional genomics in grass carp.
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How do variable substitution rates influence Ka and Ks calculations?
Genomics Proteomics Bioinformatics
PUBLISHED: 12-01-2009
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The ratio of nonsynonymous substitution rate (Ka) to synonymous substitution rate (Ks) is widely used as an indicator of selective pressure at sequence level among different species, and diverse mutation models have been incorporated into several computing methods. We have previously developed a new gamma-MYN method by capturing a key dynamic evolution trait of DNA nucleotide sequences, in consideration of varying mutation rates across sites. We now report a further improvement of NG, LWL, MLWL, LPB, MLPB, and YN methods based on an introduction of gamma distribution to illustrate the variation of raw mutation rate over sites. The novelty comes in two ways: (1) we incorporate an optimal gamma distribution shape parameter a into gamma-NG, gamma-LWL, gamma-MLWL, gamma-LPB, gamma-MLPB, and gamma-YN methods; (2) we investigate how variable substitution rates affect the methods that adopt different models as well as the interplay among four evolutional features with respect to Ka/Ks computations. Our results suggest that variable substitution rates over sites under negative selection exhibit an opposite effect on omega estimates compared with those under positive selection. We believe that the sensitivity of our new methods has been improved than that of their original methods under diverse conditions and it is advantageous to introduce novel parameters for Ka/Ks computation.
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Protein kinase C mediates the effects of delta-opioid receptor stimulation on survival and apoptosis in neonatal cardiomyocytes cultured in serum-deprived condition.
Pharmazie
PUBLISHED: 08-22-2009
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The aims of the present study were to determine whether Delta opioid receptor (delta-OR) stimulation improved the survival of cardiomyocytes cultured in serum-deprived conditions, which impaired their growth. [D-Ala2, D-Leu5]-enkephalin (DADLE), a selective delta-OR agonist, at a concentration range of 0.1 micromol/L to 10 micromol/L for 48 h increased the viability of the cardiomyocyte under serum deprivation conditions. DADLE (0.1 micromol/L) also decreased the early cell apoptosis rate and the expression of Caspase-3. The effects of 0.1 micromol/L DADLE were abolished by 10 micromol x L(-1) naltrindole, a selective delta-OR antagonist, or by blockade of protein kinase C (PKC) with its blockers, 10 micromol x L(-1) GF109203X or 1 micromol/L staurosporine. Furthermore, 0.1 micromol x L(-1) DADLE increased the expression of PKC, an effect abrogated by 10 micromol x L(-1) naltrindole. The observations indicate that delta-OR stimulation improves the viability and reduces the apoptosis via PKC pathway in neonatal cardiomyocytes cultured in serum deprived conditions.
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Retention of Vibrio parahaemolyticus in oyster tissues after chlorine dioxide treatment.
Int. J. Food Microbiol.
PUBLISHED: 07-31-2009
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Vibrio parahaemolyticus is an important food-borne bacterium that is closely related to food poisoning from consumption of raw or lightly-cooked oysters. Therefore, intensive efforts must be taken to depurate the contaminated oysters. Chlorine dioxide (ClO2) is considered to be a safe and effective disinfectant and is routinely applied for treatment of drinking water and seafood. However, the retention of V. parahaemolyticus in oyster tissues has not yet been explored after using ClO2 as a disinfectant. To address this lack of information, oysters (Crassostrea gigas) were artificially contaminated with V. parahaemolyticus (ATCC 17802). Individual oysters, the gills and the digestive glands were analyzed by spreading supernatants from homogenized tissues onto thiosulfate-citrate-bile-salt sucrose agar and polymerase chain reaction assays on the resulting bacterial colonies. V. parahaemolyticus that bioaccumulated in different oyster tissues could be disinfected completely after 6h of treatment with 20mg/L of ClO2. Thus, ClO2 appears to be a candidate disinfectant for V. parahaemolyticus depuration in oysters. The digestive glands appear to be a promising target tissue for detection of bacterial pathogens in oysters, using either conventional methods or molecular assays. The shelf life of oysters was extended to at least 12days following 6h of ClO2 treatment at 4 degrees C.
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[Beverage consumption of community residents and influencing factors].
Wei Sheng Yan Jiu
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To investigate the beverage consumption and affective factors about residents of Suzhou and provide basic information for nutrition improvement.
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[Comparison of the total arsenic concentration between saliva and blood after oral administration of sodium arsenite to rats].
Wei Sheng Yan Jiu
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To compare the total arsenic concentration between blood and saliva after oral administration of sodium arsenite to SD rats.
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The Rice Genome Knowledgebase (RGKbase): an annotation database for rice comparative genomics and evolutionary biology.
Nucleic Acids Res.
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Over the past 10 years, genomes of cultivated rice cultivars and their wild counterparts have been sequenced although most efforts are focused on genome assembly and annotation of two major cultivated rice (Oryza sativa L.) subspecies, 93-11 (indica) and Nipponbare (japonica). To integrate information from genome assemblies and annotations for better analysis and application, we now introduce a comparative rice genome database, the Rice Genome Knowledgebase (RGKbase, http://rgkbase.big.ac.cn/RGKbase/). RGKbase is built to have three major components: (i) integrated data curation for rice genomics and molecular biology, which includes genome sequence assemblies, transcriptomic and epigenomic data, genetic variations, quantitative trait loci (QTLs) and the relevant literature; (ii) User-friendly viewers, such as Gbrowse, GeneBrowse and Circos, for genome annotations and evolutionary dynamics and (iii) Bioinformatic tools for compositional and synteny analyses, gene family classifications, gene ontology terms and pathways and gene co-expression networks. RGKbase current includes data from five rice cultivars and species: Nipponbare (japonica), 93-11 (indica), PA64s (indica), the African rice (Oryza glaberrima) and a wild rice species (Oryza brachyantha). We are also constantly introducing new datasets from variety of public efforts, such as two recent releases-sequence data from ?1000 rice varieties, which are mapped into the reference genome, yielding ample high-quality single-nucleotide polymorphisms and insertions-deletions.
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Identification of genes differentially expressed in the roots of rubber tree (Hevea brasiliensis Muell. Arg.) in response to phosphorus deficiency.
Mol. Biol. Rep.
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Phosphorus (P) is an essential macronutrient for plant growth and development. P deficiency could affect rubber tree productivity seriously, and understanding the mechanism responses of the rubber tree under the P deficiency will be helpful to improving rubber tree productivity. The molecular mechanism by which the rubber trees respond to a P-deficiency is a complex network involving many processes. To identify the genes differentially expressed in that response, we constructed subtractive suppression hybridization libraries for roots of plants growing under deficient or sufficient conditions. We identified 94 up-regulated genes from the forward library and 45 down-regulated from the reverse library. These differentially expressed genes were categorized into eight groups representing functions in metabolism, transcription, signal transduction, protein synthesis, transport, stress responses, photosynthesis, and development. We also performed quantitative real-time PCR to investigate the expression profiles of eight randomly selected clones. Our results provide useful information for further study of the molecular mechanism for adaptations to a P-deficiency in this species. Further characterization and functional analysis of these differentially expressed genes will help us improve its phosphorus utilization and overall productivity.
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Conflicting roles of nickel in controlling cathode performance in lithium ion batteries.
Nano Lett.
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A variety of approaches are being made to enhance the performance of lithium ion batteries. Incorporating multivalence transition-metal ions into metal oxide cathodes has been identified as an essential approach to achieve the necessary high voltage and high capacity. However, the fundamental mechanism that limits their power rate and cycling stability remains unclear. The power rate strongly depends on the lithium ion drift speed in the cathode. Crystallographically, these transition-metal-based cathodes frequently have a layered structure. In the classic wisdom, it is accepted that lithium ion travels swiftly within the layers moving out/in of the cathode during the charge/discharge. Here, we report the unexpected discovery of a thermodynamically driven, yet kinetically controlled, surface modification in the widely explored lithium nickel manganese oxide cathode material, which may inhibit the battery charge/discharge rate. We found that during cathode synthesis and processing before electrochemical cycling in the cell nickel can preferentially move along the fast diffusion channels and selectively segregate at the surface facets terminated with a mix of anions and cations. This segregation essentially can lead to a higher lithium diffusion barrier near the surface region of the particle. Therefore, it appears that the transition-metal dopant may help to provide high capacity and/or high voltage but can be located in a "wrong" location that may slow down lithium diffusion, limiting battery performance. In this circumstance, limitations in the properties of lithium ion batteries using these cathode materials can be determined more by the materials synthesis issues than by the operation within the battery itself.
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Expression of efflux pump gene lde in ciprofloxacin-resistant foodborne isolates of Listeria monocytogenes.
Microbiol. Immunol.
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The expression of efflux pump gene lde in ciprofloxacin resistant (Cip(R) ) and susceptible strains of Listeria monocytogenes collected from retail food samples was investigated. For two Cip(R) strains, the MICs of ciprofloxacin decreased four- to eightfold in the presence of reserpine; however, no significant alterations were observed with naturally sensitive isolates. Overexpression of the lde gene induced by ciprofloxacin was observed in two resistant isolates. The present findings indicate that expression of lde and the MICs of ciprofloxacin are well correlated with the presence and absence of reserpine, suggesting that Lde might be involved in ciprofloxacin resistance of L. monocytogenes.
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A simple and highly efficient route to the synthesis of NaLnF4-Ag hybrid nanorice with excellent SERS performances.
Analyst
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This paper reports the synthesis of a new class of NaLnF(4)-Ag (Ln = Nd, Sm, Eu, Tb, Ho) hybrid nanorice and its application as a surface-enhanced Raman scattering (SERS) substrate in chemical analyses. Rice-shaped NaLnF(4) nanoparticles as templates are prepared by a modified hydrothermal method. Then, the NaLnF(4) nanorice particles are decorated with Ag nanoparticles by magnetron sputtering method to form NaLnF(4)-Ag hybrid nanostructures. The high-density Ag nanogaps on NaLnF(4) can be obtained by the prolonging sputtering times or increasing the sputtering powers. These nanogaps can serve as Raman hot spots, leading to dramatic enhancement of the Raman signal. The NaLnF(4)-Ag hybrid nanorice is found to be robust and is an efficient SERS substrate for the vibrational spectroscopic characterization of molecular adsorbates; the Raman enhancement factor of Rhodamine 6G (R6G) absorbed on NaLnF(4)-Ag nanorice is estimated to be about 10(13). Since the produced NaLnF(4)-Ag hybrid nanorice particles are firmly fastened on a silicon wafer, they can serve as universal SERS substrates to detect target analytes. We also evaluate their SERS performances using 4-mercaptopyridine (Mpy), and 4-mercaptobenzoic acid (MBA) molecules, and the detection limit for Mpy and MBA is as low as 10(-12) M and 10(-10) M, respectively, which meets the requirements of the ultratrace detection of analytes. This simple and highly efficient approach to the large-scale synthesis of NaLnF(4)-Ag nanorice with high SERS activity and sensitivity makes it a perfect choice for practical SERS detection applications.
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Transposon-derived and satellite-derived repetitive sequences play distinct functional roles in Mammalian intron size expansion.
Evol. Bioinform. Online
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Repetitive sequences (RSs) are redundant, complex at times, and often lineage-specific, representing significant "building" materials for genes and genomes. According to their origins, sequence characteristics, and ways of propagation, repetitive sequences are divided into transposable elements (TEs) and satellite sequences (SSs) as well as related subfamilies and subgroups hierarchically. The combined changes attributable to the repetitive sequences alter gene and genome architectures, such as the expansion of exonic, intronic, and intergenic sequences, and most of them propagate in a seemingly random fashion and contribute very significantly to the entire mutation spectrum of mammalian genomes.
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Occurrence of antimicrobial resistance genes sul and dfrA12 in hospital environmental isolates of Elizabethkingia meningoseptica.
World J. Microbiol. Biotechnol.
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The aim of this study was to investigate the prevalence, antimicrobial susceptibility and resistant determinants of Elizabethkingia meningoseptica in a Beijing hospital. Four hundred and eighty-seven samples from medical devices, hospital surfaces and medical staff hands were collected. In total, 26 E. meningoseptica isolates were obtained. The sinks, faucets, and drains accounted for more than half of the total number of isolates recovered. Antimicrobial susceptibility testing revealed that 24 isolates were resistant to one or more antibiotics. All strains were susceptible to piperacillin/tazobactam and vancomycin. Although the trimethoprim/sulfamethoxazole has previously been shown to exhibit good activity against E. meningoseptica, in our study 15 strains were resistant to it. We detected trimethoprim/sulfamethoxazole resistance determinants using PCR; six isolates possessed the sulI gene and four possessed the sulII gene, whilst the dfrA12 gene was detected in only one of them. Pulsed-field gel electrophoresis (PFGE) analysis showed 9 distinct types and one dominant pattern with 12 strains was found. Our data indicate that antimicrobial resistant E. meningoseptica strains exist in the hospital environment and susceptibility testing revealed that vancomycin and piperacillin/tazobactam was the most effective antibiotics. These results have practical significance for treatment of E. meningoseptica infection.
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Quiescence and attenuated DNA damage response promote survival of esophageal cancer stem cells.
J. Cell. Biochem.
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Accumulating evidence indicates cancer stem cells (CSCs) possess the capability to resist DNA-damage induced cell death, whereas the mechanism is largely unknown. Here we show that cell cycle status and DNA damage response (DDR) in CSCs probably contribute to their survival in genotoxic insults. In this study, we isolated esophageal cancer stem cells (ECSCs) from esophageal cancer cell line EC9706 by side-population (SP) phenotype through flow cytometry and found that ECSCs preferentially stay quiescent as compared to the non-ECSCs and are more resistant to DNA damage agents. Further study revealed that ECSCs express a lower level of EGFR, phosphoralated Stat3, and c-Myc, yet abnormally upregulated p27. More interestingly, different from non-ECSCs, when suffering DNA damage agents, ECSCs showed attenuated DDR, as well as declined DNA repair potential. These data indicated ECSCs probably employed an impaired DDR to handle severe genomic insults. Conclusively, we infer that the damage-resistance ability of ECSCs is likely attributed to their slow-cycling status and avoidance of apoptosis or senescence triggered by an excessive DDR.
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LBH589 enhances T cell activation in vivo and accelerates graft-versus-host disease in mice.
Biol. Blood Marrow Transplant.
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Histone deacetylase inhibitors (HDACis) are a new class of compounds that induce acetylation of histone lysine tails in chromatin and modify gene expression. The Food & Drug Administration approved HDACi, Vorinostat, or suberoylanilide hydroxamic acid (SAHA), has been shown to inhibit tumor cell growth and the production of proinflammatory cytokines. In preclinical allogeneic transplant models, SAHA induces graft-versus-host disease (GVHD) amelioration in treated mice without impairing graft-versus-leukemia. LBH589 (Panobinostat), a structurally novel cinnamic hydroxamic acid class, is an HDACi more potent than SAHA. In the current work, we tested the hypothesis that LBH589 would be highly effective in the prevention of GVHD. Using mouse model of allogeneic bone marrow transplant (BMT), we unexpectedly found that treatment with LBH589 accelerated GVHD, in contrast to the treatment with SAHA that alleviated GVHD. Accelerated GVHD in the recipients treated with LBH589 was associated with elevated Th1 cytokines in recipient serum, enhanced CXCR3 expression on donor T cells, and T cell infiltration in the liver. The current study highlights the distinct effects of pan HDACi on allogeneic BMT and alerts that LBH589 (Panobinostat) could have an adverse effect on GVHD, and possibly on other inflammatory diseases.
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IQGAP1 interacts with Aurora-A and enhances its stability and its role in cancer.
Biochem. Biophys. Res. Commun.
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IQGAP1, a ubiquitously expressed scaffold protein, has been identified in a wide range of organisms. It participates in multiple aspects of cellular events by binding to and regulating numerous interacting proteins. In our present study, we identified a new IQGAP1 binding protein named Aurora-A which is an oncogenic protein and overexpressed in various types of human tumors. In vitro analysis with GST-Aurora-A fusion proteins showed a physical interaction between Aurora-A and IQGAP1. Moreover, the binding also occurred in HeLa cells as endogenous Aurora-A co-immunoprecipitated with IQGAP1 from the cell lysates. Overexpression of IQGAP1 resulted in an elevation of both expression and activity of Aurora-A kinase. Endogenous IQGAP1 knockdown by siRNA promoted Aurora-A degradation whereas IQGAP1 overexpression enhanced the stability of Aurora-A. Additionally, we documented that the IQGAP1-induced cell proliferation was suppressed by knocking down Aurora-A expression. Taken together, our results showed an unidentified relationship between Aurora-A and IQGAP1, and provided a new insight into the molecular mechanism by which IQGAP1 played a regulatory role in cancer.
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Development of a real time PCR assay for rapid detection of Vibrio parahaemolyticus from seafood.
Protein Cell
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A real time PCR assay for the detection of Vibrio parahaemolyticus in seafood samples was developed using a novel specific target and a competitive internal amplification control (IAC). The specificity of this assay was evaluated using 390 bacterial strains including V. parahaemolyticus, and other strains belonging to Vibrio and non-Vibrio species. The real time PCR assay unambiguously distinguished V. parahaemolyticus with a detection sensitivity of 4.8 fg per PCR with purified genomic DNA or 1 CFU per reaction by counting V. parahaemolyticus colonies. The assays of avoiding interference demonstrated that, even in the presence of 2.1 ?g genomic DNA or 10(7) CFU background bacteria, V. parahaemolyticus could still be accurately detected. In addition, the IAC was used to indicate false-negative results, and lower than 94 copies of IAC per reaction had no influence on the detection limit. Ninety-six seafood samples were tested, of which 58 (60.4%) were positive, including 3 false negative results. Consequently, the real time PCR assay is effective for the rapid detection of V. parahaemotyticus contaminants in seafood.
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Concurrent highly pathogenic porcine reproductive and respiratory syndrome virus infection accelerates Haemophilus parasuis infection in conventional pigs.
Vet. Microbiol.
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This study was aimed at determining the effect of highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) on Haemophilus parasuis (HPS) in co-infection. A quantitative real-time PCR targeting infB gene, which is conserved among different HPS serotypes, was developed to improve the accuracy and speed of the detection of HPS. A total of 32 four-week-old conventional pigs were distributed randomly into four groups: pigs in group I were intranasally infected with HP-PRRSV first, and were then intraperitoneally inoculated with HPS on 5 days after HP-PRRSV infection; pigs in group II were intranasally inoculated with HP-PRRSV alone; pigs in group III were intraperitoneally inoculated with HPS alone; pigs in group IV were intraperitoneally inoculated with physiological saline. The amount of HPS in serum on 0, 3, 6, 9 and 12 days post-inoculation (dpi) with HPS were detected using the established quantitative real-time PCR. Clinical signs, pathological changes and histopathological lesions were observed. The amount of HPS in serum reached 10(6)copies/?l at 3 dpi with HPS in pigs of group I, while it arrived 10(5.7)copies/?l at 9 dpi with HPS in pigs of group III. The HPS loads in hearts and lungs were much higher than in other tissues. The study showed that HP-PRRSV was able to accelerate HPS infection and loads.
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Biomechanism of adhesion in gecko setae.
Sci China Life Sci
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The study of the adhesion of millions of setae on the toes of geckos has been advanced in recent years with the emergence of new technology and measurement methods. The theory of the mechanism of adhesion by van der Waals forces is now accepted and broadly understood. However, this paper presents limitations of this theory and gives a new hypothesis of the biomechanism of gecko adhesion. The findings are obtained through measurements of the magnitude of the adhesion of setae under three different conditions, to show the close relationship between adhesion and status of the setae. They are reinforced by demonstrating two setal structures, follicle cells and hair, the former making the setae capable of producing bioelectrical charges, which play an important role in attachment and detachment processes. It is shown that the abundant muscular tissues at the base of the setae cells, which are controlled by peripheral nerves, are instrumental in producing the foot movement involved in attachment and detachment. Our study will further uncover the adhesion mechanism of geckos, and provide new ideas for designing and fabricating synthetic setae.
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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.

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

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