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Find video protocols related to scientific articles indexed in Pubmed.
Bacterial imaging comes of age.
Sci Transl Med
PUBLISHED: 10-24-2014
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Enterobacteriaceae, a type of highly virulent Gram-negative bacteria, can be imaged in vivo in animals via positron emission tomography with (18)F-sorbitol (Weinstein et al., this issue).
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Tomato-Pseudomonas syringae interactions under elevated CO2 concentration: the role of stomata.
J. Exp. Bot.
PUBLISHED: 10-23-2014
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Increasing atmospheric CO2 concentrations ([CO2]) in agricultural and natural ecosystems is known to reduce plant stomatal opening, but it is unclear whether these CO2-induced stomatal alterations are associated with foliar pathogen infections. In this study, tomato plants were grown under ambient and elevated [CO2] and inoculated with Pseudomonas syringae pv. tomato strain DC3000, a strain that is virulent on tomato plants. We found that elevated [CO2] enhanced tomato defence against P. syringae. Scanning electron microscopy analysis revealed that stomatal aperture of elevated [CO2] plants was considerably smaller than their ambient counterparts, which affected the behaviour of P. syringae bacteria on the upper surface of epidermal peels. Pharmacological experiments revealed that nitric oxide (NO) played a role in elevated [CO2]-induced stomatal closure. Silencing key genes involved in NO generation and stomatal closing, nitrate reductase (NR) and guard cell slow-type anion channel 1 (SLAC1), blocked elevated [CO2]-induced stomatal closure and resulted in significant increases in P. syringae infection. However, the SLAC1-silenced plants, but not the NR-silenced plants, still had significantly higher defence under elevated [CO2] compared with plants treated with ambient [CO2]. Similar results were obtained when the stomata-limiting factor for P. syringae entry was excluded by syringe infiltration inoculation. These results indicate that elevated [CO2] induces defence against P. syringae in tomato plants, not only by reducing the stomata-mediated entry of P. syringae but also by invoking a stomata-independent pathway to counteract P. syringae. This information is valuable for designing proper strategies against bacterial pathogens under changing agricultural and natural ecosystems.
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Phosphoproteomics Reveals the Effect of Ethylene in Soybean Root under Flooding Stress.
J. Proteome Res.
PUBLISHED: 10-16-2014
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Flooding has severe negative effects on soybean growth. To explore the flooding-responsive mechanisms in early-stage soybean, a phosphoproteomic approach was used. Two-day-old soybean plants were treated without or with flooding for 3, 6, 12, and 24 h, and root tip proteins were then extracted and analyzed at each time point. After 3 h of flooding exposure, the fresh weight of soybeans increased, whereas the ATP content of soybean root tips decreased. Using a gel-free proteomic technique, a total of 114 phosphoproteins were identified in the root tip samples, and 34 of the phosphoproteins were significantly changed with respect to phosphorylation status after 3 h of flooding stress. Among these phosphoproteins, eukaryotic translation initiation factors were dephosphorylated, whereas several protein synthesis-related proteins were phosphorylated. The mRNA expression levels of sucrose phosphate synthase 1F and eukaryotic translation initiation factor 4G were down-regulated, whereas UDP-glucose 6-dehydrogenase mRNA expression was up-regulated during growth but down-regulated under flooding stress. Furthermore, bioinformatic protein interaction analysis of flooding-responsive proteins based on temporal phosphorylation patterns indicated that eukaryotic translation initiation factor 4G was located in the center of the network during flooding. Soybean eukaryotic translation initiation factor 4G has homology to programmed cell death 4 protein and is implicated in ethylene signaling. The weight of soybeans was increased with treatment by an ethylene-releasing agent under flooding condition, but it was decreased when plants were exposed to an ethylene receptor antagonist. These results suggest that the ethylene signaling pathway plays an important role, via the protein phosphorylation, in mechanismsof plant tolerance to the initial stages of flooding stress in soybean root tips.
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Determination of multiple phytohormones in fruits by high-performance liquid chromatography with fluorescence detection using dispersive liquid-liquid microextraction followed by pre-column fluorescent labeling.
J Sep Sci
PUBLISHED: 10-13-2014
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Plant hormone determination in food matrices has attracted more and more attention because of their potential risks to human health. However, analytical methods for the analysis of multiple plant hormones remain poorly investigated. In the present study, a convenient, selective and ultrasensitive high-performance liquid chromatography method for the simultaneous determination of multiple classes of plant hormones has been developed successfully using dispersive liquid-liquid microextraction followed by pre-column fluorescent labeling. Eight plant hormones in fruits including jasmonic acid, 12-oxo-phytodienoic acid, indole-3-acetic acid, 3-indolybutyric acid, 3-indolepropionic acid, gibberellin A3 , 1- naphthylacetic acid and 2-naphthaleneacetic acid were analyzed by this method. The conditions employed for dispersive liquid-liquid microextraction were optimized systematically. The linearity for all plant hormones was found to be > 0.9993 (R(2) values). This method offered the low detection limits of 0.19-0.44 ng/mL (at a signal-to-noise ratio of 3), and method accuracies were in the range of 92.32-103.10%. The proposed method was applied to determine plant hormones in five kinds of food samples, and this method can achieve a short analysis time, low threshold levels of detection and a high specificity for analysis of targeted plant hormones present at trace level concentrations in complex matrices. This article is protected by copyright. All rights reserved.
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Templated DNA ligation with thiol chemistry.
Org. Biomol. Chem.
PUBLISHED: 10-07-2014
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We describe two DNA-templated ligation strategies: native chemical ligation (NCL), and thiol-disulfide exchange. Both systems result in successful ligation in the presence of a DNA template. The stability of the product from the NCL reaction relies on exogenous thiol, while the thiol-disulfide reaction proceeds in a catalyst-free manner.
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Synthesis of Dihydrobenzoheterocycles through Al(OTf)3-Mediated Cascade Cyclization and Ionic Hydrogenation.
J. Org. Chem.
PUBLISHED: 10-02-2014
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A facile and versatile synthesis of dihydrobenzoheterocycles via Al(OTf)3-mediated cascade cyclization and ionic hydrogenation has been developed. The reaction is applicable to a wide range of substrates with various functional groups to afford the corresponding products in good yields.
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Sports-induced blood sugar utilization prevents development of pancreatic ductal adenocarcinoma.
Tumour Biol.
PUBLISHED: 09-13-2014
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Pancreatic ductal adenocarcinoma (PDAC) is a malignant tumor of extremely high lethality in humans. Pancreatic intraepithelial neoplasia (PanIN) is the predominant precancerous lesion for PDAC and is frequently detected in the normal and inflamed pancreas. However, only a few of PanIN eventually progress into PDAC. Thus, understanding of the regulation of PanIN-to-PDAC conversion appears to be critical for prevention of the occurrence of PDAC. Here, we evaluated the effect of sports on the progression of PanIN into PDAC in an established mouse PDAC model (Ptf1a-Cre; K-ras fx/fx). We found that swimming (3 min twice per day) since 12 weeks of age significantly decreased the incidence of the development of PDAC in these PanIN-baring mice at 24 weeks of age. Moreover, swimming significantly decreased fasting blood sugar and improved glucose response in these mice, compared to the control. Furthermore, implantation of insulin pellets into the mice not only reduced fasting blood sugar and improved glucose response, but also significantly reduced the incidence of development of PDAC, which mimicked the effect of swimming. Taken together, our study suggests that sports-induced blood sugar utilization may prevent development of PDAC.
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[Comparison of clinical characteristics and survival on patients with idiopathic pulmonary arterial hypertension and familial pulmonary arterial hypertension during conventional therapy era and targeted therapy era].
Zhonghua Xin Xue Guan Bing Za Zhi
PUBLISHED: 08-29-2014
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To compare the clinical characteristics and survival on Chinese patients with idiopathic pulmonary arterial hypertension (IPAH) and familiar pulmonary arterial hypertension (FPAH) during conventional therapy era and targeted therapy era.
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PET Imaging of Bacterial Infections with Fluorine-18-Labeled Maltohexaose.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 08-25-2014
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A positron emission tomography (PET) tracer composed of (18) F-labeled maltohexaose (MH(18) F) can image bacteria in vivo with a sensitivity and specificity that are orders of magnitude higher than those of fluorodeoxyglucose ((18) FDG). MH(18) F can detect early-stage infections composed of as few as 10(5) E. coli colony-forming units (CFUs), and can identify drug resistance in bacteria in vivo. MH(18) F has the potential to improve the diagnosis of bacterial infections given its unique combination of high specificity and sensitivity for bacteria.
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Thermally-stable resistive switching with a large ON/OFF ratio achieved in poly(triphenylamine).
Chem. Commun. (Camb.)
PUBLISHED: 08-23-2014
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Thermally stable poly(triphenylamine) (PTPA) synthesized by an oxidative coupling reaction is used as the functional layer in memory devices, which exhibit non-volatile bistable resistive switching behavior with a large ON/OFF ratio over 5 × 10(8), a long retention time exceeding 8 × 10(3) s and a wide working temperature range of 30-390 K.
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Up-regulation of HDAC4 is associated with Schwann cell proliferation after sciatic nerve crush.
Neurochem. Res.
PUBLISHED: 08-08-2014
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Histone deacetylase 4 (HDAC4), a member of the class IIa HDACs subfamily, has emerged as a critical regulator of cell growth, differentiation, and migration in various cell types. It was reported that HDAC4 stimulated colon cell proliferation via repression of p21. Also, HDAC4 contributes to platelet-derived growth factor-BB-induced proliferation and migration of vascular smooth muscle cells. Furthermore, HDAC4 may play an important role in the regulation of neuronal differentiation and survival. However, the role of HDAC4 in the process of peripheral nervous system regeneration after injury remains virtually unknown. Herein, we investigated the spatiotemporal expression of HDAC4 in a rat sciatic nerve crush model. We found that sciatic nerve crush induced up-regulated expression of HDAC4 in Schwann cells. Moreover, the expression of the proliferation marker Ki-67 exhibited a similar tendency with that of HDAC4. In cell cultures, we observed increased expression of HDAC4 during the process of TNF-?-induced Schwann cell proliferation, whereas the protein level of p21 was down-regulated. Interference of HDAC4 led to enhanced expression of p21 and impaired proliferation of Schwan cells. Taken together, our findings implicated that HDAC4 was up-regulated in the sciatic nerve after crush, which was associated with proliferation of Schwann cells.
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Protein phosphatase PP1 negatively regulates the Toll-like receptor- and RIG-I-like receptor-triggered production of type I interferon by inhibiting IRF3 phosphorylation at serines 396 and 385 in macrophage.
Cell. Signal.
PUBLISHED: 08-01-2014
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The production of type I interferon must be tightly regulated, and the aberrant production of this protein is harmful or even fatal to the host. The transcription factor IRF3 phosphorylation is a central regulator of type I interferon meditated antiviral response. Protein phosphatase-1 (PP1) has been reported to be important in many cell functions, including development, differentiation, and tumorigenesis. However, the roles of PP1 in Toll-like receptor (TLR)- or retinoic acid-inducible gene I like receptor (RLR)-triggered IRF-3 activation remain unclear. Here, we show that the activity of PP1 is downregulated in macrophages upon stimulation with TLR or RLR ligands, including lipopolysaccharide, and poly(I:C), or vesicular stomatitis virus (VSV), respectively. The overexpression of PP1 selectively inhibits TLR- and VSV-induced interferon regulatory factor 3 (IRF3) activation but has no substantial effect on TANK-binding kinase 1 (TBK1),?B kinase ? (IKK?) activation. Conversely, RNA interference of PP1 significantly promotes IRF3 activation. Consistently, The overexpression of PP1 inhibits TLR- and VSV-triggered IFN-? production while PP1 knockdown significantly increases the production of IFN-? in macrophages. We further demonstrate that PP1 directly interacts with IRF3 and dephosphorylates IRF3 at Ser385 and Ser396, resulting in the suppression of TLR- and RLR-triggered IFN-? production. Thus, PP1 functions as a negative feedback regulator of TLR- and RLR-triggered antiviral immune responses by acting as an IRF3 phosphatase.
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Biostability in distribution systems in one city in southern China: characteristics, modeling and control strategy.
J Environ Sci (China)
PUBLISHED: 08-01-2014
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This study investigated the bacterial regrowth in drinking water distribution systems receiving finished water from an advanced drinking water treatment plant in one city in southern China. Thirteen nodes in two water supply zones with different aged pipelines were selected to monitor water temperature, dissolved oxygen (DO), chloramine residual, assimilable organic carbon (AOC), and heterotrophic plate counts (HPC). Regression and principal component analyses indicated that HPC had a strong correlation with chloramine residual. Based on Chick-Watson's Law and the Monod equation, biostability curves under different conditions were developed to achieve the goal of HPC < or = 100 CFU/mL. The biostability curves could interpret the scenario under various AOC concentrations and predict the required chloramine residual concentration under the condition of high AOC level. The simulation was also carried out to predict the scenario with a stricter HPC goal (< or = 50 CFU/mL) and determine the required chloramine residual. The biological regrowth control strategy was assessed using biostability curve analysis. The results indicated that maintaining high chloramine residual concentration was the most practical way to achieve the goal of HPC < or = 100 CFU/mL. Biostability curves could be a very useful tool for biostability control in distribution systems. This work could provide some new insights towards biostability control in real distribution systems.
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[Pulmonary arterial hypertension after operation for congenital heart disease: analysis of baseline clinical characteristics of 122 Chinese patients].
Zhonghua Xin Xue Guan Bing Za Zhi
PUBLISHED: 07-22-2014
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To explore the baseline clinical characteristics of patients with pulmonary arterial hypertension after operation for congenital heart disease (AO-CHD-PAH) in China.
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Biofilm bacterial communities in urban drinking water distribution systems transporting waters with different purification strategies.
Appl. Microbiol. Biotechnol.
PUBLISHED: 07-21-2014
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Biofilm formation in drinking water distribution systems (DWDS) has many adverse consequences. Knowledge of microbial community structure of DWDS biofilm can aid in the design of an effective control strategy. However, biofilm bacterial community in real DWDS and the impact of drinking water purification strategy remain unclear. The present study investigated the composition and diversity of biofilm bacterial community in real DWDSs transporting waters with different purification strategies (conventional treatment and integrated treatment). High-throughput Illumina MiSeq sequencing analysis illustrated a large shift in the diversity and structure of biofilm bacterial community in real DWDS. Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Nitrospirae, and Cyanobacteria were the major components of biofilm bacterial community. Proteobacteria (mainly Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria) predominated in each DWDS biofilm, but the compositions of the dominant proteobacterial classes and genera and their proportions varied among biofilm samples. Drinking water purification strategy could shape DWDS biofilm bacterial community. Moreover, Pearson's correlation analysis indicated that Actinobacteria was positively correlated with the levels of total alkalinity and dissolved organic carbon in tap water, while Firmicutes had a significant positive correlation with nitrite nitrogen.
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Transforming growth factor (TGF)-?-activated kinase 1 (TAK1) activation requires phosphorylation of serine 412 by protein kinase A catalytic subunit ? (PKAC?) and X-linked protein kinase (PRKX).
J. Biol. Chem.
PUBLISHED: 07-15-2014
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TGF-?-activated kinase 1 (TAK1) is a key kinase in mediating Toll-like receptors (TLRs) and interleukin-1 receptor (IL-1R) signaling. Although TAK1 activation involves the phosphorylation of Thr-184 and Thr-187 residues at the activation loop, the molecular mechanism underlying the complete activation of TAK1 remains elusive. In this work, we show that the Thr-187 phosphorylation of TAK1 is regulated by its C-terminal coiled-coil domain-mediated dimerization in an autophosphorylation manner. Importantly, we find that TAK1 activation in mediating downstream signaling requires an additional phosphorylation at Ser-412, which is critical for TAK1 response to proinflammatory stimuli, such as TNF-?, LPS, and IL-1?. In vitro kinase and shRNA-based knockdown assays reveal that TAK1 Ser-412 phosphorylation is regulated by cAMP-dependent protein kinase catalytic subunit ? (PKAC?) and X-linked protein kinase (PRKX), which is essential for proper signaling and proinflammatory cytokine induction by TLR/IL-1R activation. Morpholino-based in vivo knockdown and rescue studies show that the corresponding site Ser-391 in zebrafish TAK1 plays a conserved role in NF-?B activation. Collectively, our data unravel a previously unknown mechanism involving TAK1 phosphorylation mediated by PKAC? and PRKX that contributes to innate immune signaling.
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Activation of STAT3 is involved in malignancy mediated by CXCL12-CXCR4 signaling in human breast cancer.
Oncol. Rep.
PUBLISHED: 07-14-2014
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The chemokine receptor CXCR4 and signal transducer and activator of transcription 3 (STAT3) play an important role in breast cancer malignancy and metastasis. However, it remains unknown whether STAT3 can be activated by CXCR4 in human breast cancer. The expression levels of CXCR4, STAT3 and p-STAT3 in 208 breast cancer tissues and 26 tumor-adjacent tissues were examined by immunohistochemistry. Flow cytometry, western blot analysis and immunoprecipitation were used to study activation of STAT3 by CXCL12-CXCR4 signaling in human breast cancer cell lines. The expression levels of CXCR4, STAT3 and p-STAT3 were higher in the breast cancer samples than these levels in the tumor-adjacent samples. The combined expression of CXCR4 and p-STAT3 was correlated with TNM stage, tumor size, lymph node metastasis and histological grade of breast cancer. In the breast cancer cells, CXCL12 treatment increased the expression of p-STAT3. The CXCR4 antagonist AMD3100 and the Janus kinase 2 (JAK2) antagonist AG490 inhibited the CXCL12-induced increase in the phosphorylation of STAT3. Furthermore, CXCL12 promoted direct binding of JAK2 to CXCR4. Our findings suggest that activation of the JAK2/STAT3 pathway via CXCL12-CXCR4 signaling plays an important role in breast cancer malignancy and metastasis. Targeting the CXCL12-CXCR4/JAK2/STAT3 signaling pathway may be a potential therapeutic strategy for the treatment of breast cancer.
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Thermally assisted electric field control of magnetism in flexible multiferroic heterostructures.
Sci Rep
PUBLISHED: 07-07-2014
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Thermal and electrical control of magnetic anisotropy were investigated in flexible Fe81Ga19 (FeGa)/Polyvinylidene fluoride (PVDF) multiferroic heterostructures. Due to the large anisotropic thermal deformation of PVDF (?1 = -13 × 10(-6)?K(-1) and ?2 = -145 × 10(-6)?K(-1)), the in-plane uniaxial magnetic anisotropy (UMA) of FeGa can be reoriented 90° by changing the temperature across 295?K where the films are magnetically isotropic. Thus, the magnetization of FeGa can be reversed by the thermal cycling between 280 and 320?K under a constant magnetic field lower than coercivity. Moreover, under the assistance of thermal deformation with slightly heating the samples to the critical temperature, the electric field of ± 267?kV cm(-1) can well align the UMA along the two orthogonal directions. The new route of combining thermal and electrical control of magnetic properties realized in PVDF-based flexible multiferroic materials shows good prospects in application of flexible thermal spintronic devices and flexible microwave magnetic materials.
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Heparin inhibits burn-induced spleen cell apoptosis by suppressing interleukin-1 expression.
Chin. Med. J.
PUBLISHED: 07-03-2014
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Epidermal burn injury may trigger significant apoptosis of the spleen cells, which might be caused by a burn-induced systemic inflammatory reaction. Heparin has been shown to possess anti-inflammatory properties. Interleukin 1 (IL-1) is centrally important among pro-inflammatory cytokines. We hypothesized that heparin might inhibit burn-induced apoptosis in the spleen via suppression of the IL-1 pathway.
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Deciphering the heterogeneity in DNA methylation patterns during stem cell differentiation and reprogramming.
BMC Genomics
PUBLISHED: 06-30-2014
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Human induced pluripotent stem cells (iPSCs) have a wide range of applications throughout the fields of basic research, disease modeling and drug screening. Epigenetic instable iPSCs with aberrant DNA methylation may divide and differentiate into cancer cells. Unfortunately, little effort has been taken to compare the epigenetic variation in iPSCs with that in differentiated cells. Here, we developed an analytical procedure to decipher the DNA methylation heterogeneity of mixed cells and further exploited it to quantitatively assess the DNA methylation variation in the methylomes of adipose-derived stem cells (ADS), mature adipocytes differentiated from ADS cells (ADS-adipose) and iPSCs reprogrammed from ADS cells (ADS-iPSCs).
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PIGD: a database for intronless genes in the Poaceae.
BMC Genomics
PUBLISHED: 06-30-2014
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Intronless genes are a feature of prokaryotes; however, they are widespread and unequally distributed among eukaryotes and represent an important resource to study the evolution of gene architecture. Although many databases on exons and introns exist, there is currently no cohesive database that collects intronless genes in plants into a single database.
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Positive temperature coefficient of magnetic anisotropy in polyvinylidene fluoride (PVDF)-based magnetic composites.
Sci Rep
PUBLISHED: 06-26-2014
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The magnetic anisotropy is decreased with increasing temperature in normal magnetic materials, which is harmful to the thermal stability of magnetic devices. Here, we report the realization of positive temperature coefficient of magnetic anisotropy in a novel composite combining ?-phase polyvinylidene fluoride (PVDF) with magnetostrictive materials (magnetostrictive film/PVDF bilayer structure). We ascribe the enhanced magnetic anisotropy of the magnetic film at elevated temperature to the strain-induced anisotropy resulting from the anisotropic thermal expansion of the ?-phase PVDF. The simulation based on modified Stoner-Wohlfarth model and the ferromagnetic resonance measurements confirms our results. The positive temperature coefficient of magnetic anisotropy is estimated to be 1.1 × 10(2)?J m(-3) K(-1). Preparing the composite at low temperature can enlarge the temperature range where it shows the positive temperature coefficient of magnetic anisotropy. The present results may help to design magnetic devices with improved thermal stability and enhanced performance.
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Cloning and Characterization of a Multifunctional Promoter from Maize (Zea mays L.).
Appl. Biochem. Biotechnol.
PUBLISHED: 06-23-2014
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The use of tissue-specific promoters to drive the expression of target genes during certain developmental stages or in specific organs can prevent unnecessary gene expression caused by constitutive promoters. Utilizing heterologous promoters to regulate the expression of genes in transgenic receptors can help prevent gene silencing. Here, we engineered heterologous maize promoters that regulate gene-specific expression in rice plant receptors. We performed a histochemical and quantitative ?-glucuronidase (GUS) analysis of the Zea mays legumin1 (ZM-LEGF) gene promoter and detailed detection of stably transformed rice expressing the GUS gene under the control of the promoter of ZM-LEGF (pZM-LEGF) and its truncated promoters throughout development. When the promoter sequence was truncated, the location and intensity of GUS expression changed. The results suggest that the sequence from -140 to +41 is a critical region that confers the expression of the entire promoter. Truncation of pZM-LEG (3'-deleted region of pZM-LEGF) markedly increased the GUS activity, with the core cis-elements located in the -273 to -140 regions, namely pZM-LEG6. Detailed analysis of pZM-LEG6::GUS T2 transformant rice seeds and plant tissues at different developmental stages indicated that this promoter is an ideal vegetative tissue-specific promoter that can serve as a valuable tool for transgenic rice breeding and genetic engineering studies.
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Salicylic acid binding of mitochondrial alpha-ketoglutarate dehydrogenase E2 affects mitochondrial oxidative phosphorylation and electron transport chain components and plays a role in basal defense against tobacco mosaic virus in tomato.
New Phytol.
PUBLISHED: 06-16-2014
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Salicylic acid (SA) plays a critical role in plant defense against pathogen invasion. SA-induced viral defense in plants is distinct from the pathways mediating bacterial and fungal defense and involves a specific pathway mediated by mitochondria; however, the underlying mechanisms remain largely unknown. The SA-binding activity of the recombinant tomato (Solanum lycopersicum) alpha-ketoglutarate dehydrogenase (Sl?-kGDH) E2 subunit of the tricarboxylic acid (TCA) cycle was characterized. The biological role of this binding in plant defenses against tobacco mosaic virus (TMV) was further investigated via Sl?-kGDH E2 silencing and transient overexpression in plants. Sl?-kGDH E2 was found to bind SA in two independent assays. SA treatment, as well as Sl?-kGDH E2 silencing, increased resistance to TMV. SA did not further enhance TMV defense in Sl?-kGDH E2-silenced tomato plants but did reduce TMV susceptibility in Nicotiana benthamiana plants transiently overexpressing Sl?-kGDH E2. Furthermore, Sl?-kGDH E2-silencing-induced TMV resistance was fully blocked by bongkrekic acid application and alternative oxidase 1a silencing. These results indicated that binding by Sl?-kGDH E2 of SA acts upstream of and affects the mitochondrial electron transport chain, which plays an important role in basal defense against TMV. The findings of this study help to elucidate the mechanisms of SA-induced viral defense.
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Operational performance, biomass and microbial community structure: impacts of backwashing on drinking water biofilter.
Environ Sci Pollut Res Int
PUBLISHED: 06-03-2014
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Biofiltration has been widely used to reduce organic matter and control the formation of disinfection by-products in drinking water. Backwashing might affect the biofilters' performance and the attached microbiota on filter medium. In this study, the impacts of backwashing on the removal of dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and N-nitrosamine precursors by a pilot-scale biological activated carbon (BAC) filtration system were investigated. The impacts of backwashing on biomass and microbial community structure of BAC biofilm were also investigated. Phospholipid fatty acid (PLFA) analysis showed that backwashing reduced nearly half of the attached biomass on granular activated carbon (GAC) particles, followed by a recovery to the pre-backwashing biomass concentration in 2 days after backwashing. Backwashing was found to transitionally improve the removal of DOC, DON and N-nitrosamine precursors. MiSeq sequencing analysis revealed that backwashing had a strong impact on the bacterial diversity and community structure of BAC biofilm, but they could gradually recover with the operating time after backwashing. Phylum Proteobacteria was the largest bacterial group in BAC biofilm. Microorganisms from genera Bradyrhizobium, Hyphomicrobium, Microcystis and Sphingobium might contribute to the effective removal of nitrogenous organic compounds by drinking water biofilter. This work could add some new insights towards the operation of drinking water biofilters and the biological removal of organic matter.
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All-trans retinoic acid suppresses apoptosis in PC12 cells injured by oxygen and glucose deprivation via the retinoic acid receptor ? signaling pathway.
Mol Med Rep
PUBLISHED: 05-29-2014
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Vitamin A (VA) has a number of important biological functions in human growth and development. Previous studies by our group demonstrated that the normal VA levels improved recovery of learning and memory function and decreased apoptosis in rats with hypoxic?ischemic brain damage (HIBD). However, it has not been fully elucidated how VA regulates the apoptosis of neuronal cells. To investigate the anti?apoptotic effect of VA, an in vitro oxygen glucose deprivation (OGD) model in PC12 cells was treated with four concentrations of all?trans?retinoic acid (ATRA), an active in vivo product of VA. Following in vitro OGD injury in PC12 cells, the percentage of apoptosis and the fluorescence intensity of the mitochondrial membrane potential (MMP) were increased in the cells, and the expression levels of B-cell lymphoma-associated X (Bax) were enhanced. ATRA treatment at 2?4 µmol/l for 24 h decreased the percentage of apoptosis and the MMP of the PC12 cells injured by OGD. ATRA at 4 µmol/l also reduced the expression levels of Bax and enhanced the expression of B-cell lymphoma 2. Furthermore, RNA interference with retinoic acid receptor ? (RAR?) reversed the observed effect in PC12 cells following ATRA treatment at 4 µmol/l alone. In conclusion, the present study suggested that treatment with ATRA at 4 µmol/l suppressed apoptosis of PC12 cells following OGD injury, potentially through regulation of the RAR? signaling pathway.
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The dynamics of DNA methylation fidelity during mouse embryonic stem cell self-renewal and differentiation.
Genome Res.
PUBLISHED: 05-16-2014
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The faithful transmission of DNA methylation patterns through cell divisions is essential for the daughter cells to retain a proper cell identity. To achieve a comprehensive assessment of methylation fidelity, we implemented a genome-scale hairpin bisulfite sequencing approach to generate methylation data for DNA double strands simultaneously. We show here that methylation fidelity increases globally during differentiation of mouse embryonic stem cells (mESCs), and is particularly high in the promoter regions of actively expressed genes and positively correlated with active histone modification marks and binding of transcription factors. The majority of intermediately (40%-60%) methylated CpG dinucleotides are hemi-methylated and have low methylation fidelity, particularly in the differentiating mESCs. While 5-hmC and 5-mC tend to coexist, there is no significant correlation between 5-hmC levels and methylation fidelity. Our findings may shed new light on our understanding of the origins of methylation variations and the mechanisms underlying DNA methylation transmission.
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Curcumin induced human gastric cancer BGC-823 cells apoptosis by ROS-mediated ASK1-MKK4-JNK stress signaling pathway.
Int J Mol Sci
PUBLISHED: 05-14-2014
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The signaling mediated by stress-activated MAP kinases (MAPK), c-Jun N-terminal kinase (JNK) has well-established importance in cancer. In the present report, we investigated the effects of curcumin on the signaling pathway in human gastric cancer BGC-823 cells. Curcumin induced reactive oxygen species (ROS) production and BGC-823 cells apoptosis. Inhibition of ROS generation by antioxidant (NAC or Trion) significantly prevented curcumin-mediated apoptosis. Notably, we observed that curcumin activated ASK1, a MAPKKK that is oxidative stress sensitive and responsible to phosphorylation of JNK via triggering cascades, up-regulated an upstream effector of the JNK, MKK4, and phosphorylated JNK protein expression in BGC-823 cells. However, curcumin induced ASK1-MKK4-JNK signaling was attenuated by NAC. All the findings confirm the possibility that oxidative stress-activated ASK1-MKK4-JNK signaling cascade promotes the apoptotic response in curcumin-treated BGC-823 cells.
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A novel Maize homeodomain-leucine zipper (HD-Zip) I gene, Zmhdz10, positively regulates drought and salt tolerance in both rice and Arabidopsis.
Plant Cell Physiol.
PUBLISHED: 05-08-2014
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Increasing evidence suggests that homeodomain-leucine zipper I (HD-Zip) I transcription factors play important roles in abiotic stress responses, but no HD-Zip I proteins have been reported in maize. Here, a drought-induced HD-Zip I gene, Zmhdz10, was isolated from maize and characterized for its role in stress responses. Real-time quantitative PCR showed that expression of Zmhdz10 was also induced by salt stress and ABA. Transient expression of Zmhdz10-green fluorescent protein (GFP) fusion proteins in onion cells showed a nuclear localization of Zmhdz10. Yeast hybrid assays demonstrated that Zmhdz10 has transactivation and DNA-binding activity in yeast cells. Overexpression of Zmhdz10 in rice led to enhanced tolerance to drought and salt stresses and increased sensitivity to ABA. Moreover, Zmhdz10 transgenic plants had lower relative electrolyte leakage (REL), lower malondialdehyde (MDA) and increased proline content relative to wild-type plants under stress conditions, which may contribute to enhanced stress tolerance. Zmhdz10 transgenic Arabidopsis plants also exhibited enhanced tolerance to drought and salt stresses that was concomitant with altered expression of stress/ABA-responsive genes, including ?1-Pyrroline-5-carboxylate synthetase 1 (P5CS1), Responsive to dehydration 22 (RD22), Responsive to dehydration 29B (RD29B) and ABA-insensitive 1 (ABI1). Taken together, these results suggest that Zmhdz10 functions as a transcriptional regulator that can positively regulate drought and salt tolerance in plants through an ABA-dependent signaling pathway.
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Discovery of oxazole and triazole derivatives as potent and selective S1P(1) agonists through pharmacophore-guided design.
Eur J Med Chem
PUBLISHED: 04-22-2014
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We have discovered a series of triazole/oxazole-containing 2-substituted 2-aminopropane-1,3-diol derivatives as potent and selective S1P1 agonists (prodrugs) based on pharmacophore-guided rational design. Most compounds showed high affinity and selectivity for S1P1 receptor. Compounds 19b, 19d and 19p displayed clear dose responsiveness in the lymphocyte reduction model when administered orally at doses of 0.3, 1.0, 3.0 mg/kg with reduced effect on heart rate. These three compounds were also identified to have favorable pharmacokinetic properties.
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Involvement of upregulated SYF2 in Schwann cell differentiation and migration after sciatic nerve crush.
Cell. Mol. Neurobiol.
PUBLISHED: 04-21-2014
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SYF2 is a putative homolog of human p29 in Saccharomyces cerevisiae. It seems to be involved in pre-mRNA splicing and cell cycle progression. Disruption of SYF2 leads to reduced ?-tubulin expression and delayed nerve system development in zebrafish. Due to the potential of SYF2 in modulating microtubule dynamics in nervous system, we investigated the spatiotemporal expression of SYF2 in a rat sciatic nerve crush (SNC) model. We found that SNC resulted in a significant upregulation of SYF2 from 3 days to 1 week and subsequently returned to the normal level at 4 weeks. At its peak expression, SYF2 distributed predominantly in Schwann cells. In addition, upregulation of SYF2 was approximately in parallel with Oct-6, and numerous Schwann cells expressing SYF2 were Oct-6 positive. In vitro, we observed enhanced expression of SYF2 during the process of cyclic adenosine monophosphate (cAMP)-induced Schwann cell differentiation. SYF2-specific siRNA-transfected Schwann cells did not show significant morphological change in the process of Schwann cell differentiation. Also, we found shorter and disorganized microtubule structure and a decreased migration in SYF2-specific siRNA-transfected Schwann cells. Together, these findings indicated that the upregulation of SYF2 was associated with Schwann cell differentiation and migration following sciatic nerve crush.
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Different evolutionary patterns among intronless genes in maize genome.
Biochem. Biophys. Res. Commun.
PUBLISHED: 04-16-2014
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Intronless genes, as a characteristic feature of prokaryotes, are an important resource for the study of the evolution of gene architecture in eukaryotes. In the study, 14,623 (36.87%) intronless genes in maize were identified and the percentage is greater than that of other monocots and algae. The number of maize intronless genes on each chromosome has a significant linear correlation with the number of total genes on the chromosome and the length of the chromosomes. Intronless genes in maize play important roles in translation and energy metabolism. Evolutionary analysis revealed that 2601 intronless genes conserved among the three domains of life and 2323 intronless genes that had no homology with genes of other species. These two sets of intronless genes were distinct in genetic features, physical locations and function. These results provided a useful source to understand the evolutionary patterns of related genes and genomes and some intronless genes are good candidates for subsequent functional analyses specifically.
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MiR-451 is decreased in hypertrophic cardiomyopathy and regulates autophagy by targeting TSC1.
J. Cell. Mol. Med.
PUBLISHED: 04-09-2014
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The molecular mechanisms that drive the development of cardiac hypertrophy in hypertrophic cardiomyopathy (HCM) remain elusive. Accumulated evidence suggests that microRNAs are essential regulators of cardiac remodelling. We have been suggested that microRNAs could play a role in the process of HCM. To uncover which microRNAs were changed in their expression, microRNA microarrays were performed on heart tissue from HCM patients (n = 7) and from healthy donors (n = 5). Among the 13 microRNAs that were differentially expressed in HCM, miR-451 was the most down-regulated. Ectopic overexpression of miR-451 in neonatal rat cardiomyocytes (NRCM) decreased the cell size, whereas knockdown of endogenous miR-451 increased the cell surface area. Luciferase reporter assay analyses demonstrated that tuberous sclerosis complex 1 (TSC1) was a direct target of miR-451. Overexpression of miR-451 in both HeLa cells and NRCM suppressed the expression of TSC1. Furthermore, TSC1 was significantly up-regulated in HCM myocardia, which correlated with the decreased levels of miR-451. As TSC1 is a known positive regulator of autophagy, we examined the role of miR-451 in the regulation of autophagy. Overexpression of miR-451 in vitro inhibited the formation of the autophagosome. Conversely, miR-451 knockdown accelerated autophagosome formation. Consistently, an increased number of autophagosomes was observed in HCM myocardia, accompanied by up-regulated autophagy markers, and the lipidated form of LC3 and Beclin-1. Taken together, our findings indicate that miR-451 regulates cardiac hypertrophy and cardiac autophagy by targeting TSC1. The down-regulation of miR-451 may contribute to the development of HCM and may be a potential therapeutic target for this disease.
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Near?infrared fluorescence imaging of prostate cancer using heptamethine carbocyanine dyes.
Mol Med Rep
PUBLISHED: 04-02-2014
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Near?infrared fluorescence (NIRF) imaging is an attractive novel modality for the detection of cancer. A previous study defined two organic polymethine cyanine dyes as ideal NIRF probes, IR?783 and its derivative MHI?148, which have excellent optical characteristics, superior biocompatibility and cancer targeting abilities. To investigate the feasibility of NIRF dye?mediated prostate cancer imaging, dye uptake and subcellular co?localization were investigated in PC?3, DU?145 and LNCaP human prostate cancer cells and RWPE?1 normal prostate epithelial cells. Different organic anion transporting peptide (OATP) inhibitors were utilized to explore the potential role of the OATP subtype, including the nonspecific OATP inhibitor bromosulfophthalein, the OATP1 inhibitor 17??estradiol, the selective OATP1B1 inhibitor rifampicin and the selective OATP1B3 inhibitor cholecystokinin octapeptide. NIRF dyes were also used for the simulated detection of circulating tumor cells and the rapid detection of prostate cancer in human prostate cancer tissues and prostate cancer xenografts in mouse models. The results revealed that the cancer?specific uptake of these organic dyes in prostate cancer cells occurred primarily via OATP1B3. A strong NIRF signal was detected in prostate cancer tissues, but not in normal tissues that were stained with IR?783. Prostate cancer cells were recognized with particular NIR fluorescence in isolated mononuclear cell mixtures. The results of the present study demonstrated that NIRF dye?mediated imaging is a feasible and practicable method for prostate cancer detection, although further investigative studies are required before clinical translation.
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High-dose supplementation with vitamin C--induced pediatric urolithiasis: the first case report in a child and literature review.
Urology
PUBLISHED: 04-02-2014
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High dose of vitamin C intake could increase urine oxalate excretion and hence the risk of calcium stone formation. We report a case of left ureteral stone in a 9-year-old boy with an extremely high urine oxalate excretion. Besides, he had a habit of taking high-dose supplementation of vitamin C since the age of 3 years. After vitamin C intake prohibited without other therapy and change of dietary intake, the urine oxalate excretion was decreased to normal level and no recurrence of urolithiasis was present during the 3-year follow-up. Thus, high-dose supplementation with vitamin C for years in a child could induce the urinary stones.
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para-Quinodimethane-bridged perylene dimers and pericondensed quaterrylenes: the effect of the fusion mode on the ground states and physical properties.
Chemistry
PUBLISHED: 03-29-2014
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Polycyclic hydrocarbon compounds with a singlet biradical ground state show unique physical properties and promising material applications; therefore, it is important to understand the fundamental structure/biradical character/physical properties relationships. In this study, para-quinodimethane (p-QDM)-bridged quinoidal perylene dimers 4 and 5 with different fusion modes and their corresponding aromatic counterparts, the pericondensed quaterrylenes 6 and 7, were synthesized. Their ground-state electronic structures and physical properties were studied by using various experiments assisted with DFT calculations. The proaromatic p-QDM-bridged perylene monoimide dimer 4 has a singlet biradical ground state with a small singlet/triplet energy gap (-2.97?kcal?mol(-1)), whereas the antiaromatic s-indacene-bridged N-annulated perylene dimer 5 exists as a closed-shell quinoid with an obvious intramolecular charge-transfer character. Both of these dimers showed shorter singlet excited-state lifetimes, larger two-photon-absorption cross sections, and smaller energy gaps than the corresponding aromatic quaterrylene derivatives 6 and 7, respectively. Our studies revealed how the fusion mode and aromaticity affect the ground state and, consequently, the photophysical properties and electronic properties of a series of extended polycyclic hydrocarbon compounds.
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Upregulated Expression of Ebp1 Contributes to Schwann Cell Differentiation and Migration After Sciatic Nerve Crush.
J. Mol. Neurosci.
PUBLISHED: 03-29-2014
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Ebp1, an ErbB3-binding protein, is the human homologue of the cell cycle-regulated mouse protein p38-2G4. Ebp1 was reported to inhibit the proliferation and induce the differentiation of human cancer cells. Its p48 isoform contributes to neuronal differentiation and growth factor specificity. However, the expression and role of Ebp1 in peripheral system lesions and repair are still unknown. Herein, we investigated the spatiotemporal pattern of Ebp1 expression following sciatic nerve crush. After crush, the level of Ebp1 protein was elevated gradually, peaked at day 5, and then declined to the normal at 4 weeks, which was similar to the expression of Oct-6. Furthermore, using double immunofluorescent staining, we found Ebp1 had a colocalization with S100 and Oct-6 in 5-day injured tissues. In vitro, we observed enhanced expression of Ebp1 during the process of cyclic adenosine monophosphate (cAMP)-induced Schwann cells differentiation. Interestingly, Ebp1-depleted SCs did not show significant morphologic change after the treatment of cAMP. Also, we observed a colocalization between Ebp1 and Cyclin D1 and that Ebp1-specific siRNA-transfected SCs had a decreased migration. Taken together, we speculated that Ebp1 was upregulated in the sciatic nerve after crush, which was involved in the differentiation and migration of Schwann cells.
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[Detection of leukemia-derived microparticles in the monitoring of chronic myeloid leukemia].
Zhonghua Xue Ye Xue Za Zhi
PUBLISHED: 03-11-2014
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To exam the role of leukemia cells-derived microparticles in the post-complete molecular response stratification.
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Dimethylamine biodegradation by mixed culture enriched from drinking water biofilter.
Chemosphere
PUBLISHED: 02-28-2014
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Dimethylamine (DMA) is one of the important precursors of drinking water disinfection by-product N-nitrosodimethylamine (NDMA). Reduction of DMA to minimize the formation of carcinogenic NDMA in drinking water is of practical importance. Biodegradation plays a major role in elimination of DMA pollution in the environment, yet information on DMA removal by drinking water biofilter is still lacking. In this study, microcosms with different treatments were constructed to investigate the potential of DMA removal by a mixed culture enriched from a drinking water biofilter and the effects of carbon and nitrogen sources. DMA could be quickly mineralized by the enrichment culture. Amendment of a carbon source, instead of a nitrogen source, had a profound impact on DMA removal. A shift in bacterial community structure was observed with DMA biodegradation, affected by carbon and nitrogen sources. Proteobacteria was the predominant phylum group in DMA-degrading microcosms. Microorganisms from a variety of bacterial genera might be responsible for the rapid DMA mineralization.
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Development of a selective S1P1 receptor agonist, Syl930, as a potential therapeutic agent for autoimmune encephalitis.
Biochem. Pharmacol.
PUBLISHED: 02-28-2014
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Sphingosine-1-phosphate receptor subtype 1 (S1P1) is essential for lymphocyte egress from secondary lymphoid organs and is a validated drug target for the treatment of autoimmune disorders. However, during the preclinical and clinical trials of S1P1 modulators, the undesired activation of S1P3, a subtype of sphingosine 1-phosphate (S1P) receptors family, by S1P1 modulators often results in bradycardia in patients. Thus, we designed and synthesized a new series of selective S1P1 agonists. One of them, Syl930 (the prodrug), is preference to activate S1P1 but not S1P3. In this study, we further investigated the therapeutic potential of Syl930 on an experimental autoimmune encephalomyelitis (EAE) model in Lewis rats. We found that Syl930 can activate and internalize S1P1 receptors and effectively decreased the periphery blood lymphocytes (PBL) in SD rats, and subsequently rendered PBL insensitive to egress signal from secondary lymphoid organs (SLO). Intriguingly, the treatment of Syl930 did not bring any side effect on heart rate of the tested rats. Furthermore, the suppressed PBL caused by Syl930 was able to recover within 3 days after the last dose of treatment, which is correlated to the relatively short elimination half-life of Syl930. In the rat EAE model, therapeutic treatment with Syl930 significantly inhibited the progression of EAE and EAE-associated histological changes in brain and spinal cord of Lewis rats. These results illustrate that, as a selective S1P1 agonist, Syl930 exhibits a profound and rapidly reversible suppression of lymphocyte trafficking and it has the potential to serve as a therapeutic agent for autoimmune encephalitis.
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Complicated variation of simple renal cyst usually means malignancy: results from a cohort study.
World J Surg Oncol
PUBLISHED: 02-18-2014
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Currently, simple renal cysts (SRCs) are not considered to warrant follow-up or specific treatment unless a patient presents symptomatically. By demonstrating malignant transformation of SRCs, we urge regular follow-up and timely surgical treatment in affected patients.
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Phosphatase holoenzyme PP1/GADD34 negatively regulates TLR response by inhibiting TAK1 serine 412 phosphorylation.
J. Immunol.
PUBLISHED: 02-17-2014
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The molecular mechanisms that fine tune TLRs responses need to be fully elucidated. Protein phosphatase-1 (PP1) has been shown to be important in cell death and differentiation. However, the roles of PP1 in TLR-triggered immune response remain unclear. In this study, we demonstrate that PP1 inhibits the activation of the MAPK and NF-?B pathway and the production of TNF-?, IL-6 in macrophages triggered by TLR3, TLR4, and TLR9 in a phosphatase-dependent manner. Conversely, PP1 knockdown increases TLRs-triggered signaling and proinflammatory cytokine production. Tautomycetin, a specific inhibitor of PP1, aggravates LPS-induced endotoxin shock in mice. We further demonstrate that PP1 negatively regulates TLR-triggered signaling by targeting TGF-?-activated kinase 1 (TAK1) serine 412 (Ser412) phosphorylation, which is required for activation of TAK1-mediated IL-1R and TLR signaling. Mutation of TAK1 Serine 412 to alanine (S412A) significantly inhibits TLR/IL-1R-triggered NF-?B and MAPK activation and induction of proinflammatory cytokines in macrophage and murine embryonic fibroblast cells. DNA damage-inducible protein 34 (GADD34) specifies PP1 to dephosphorylate TAK1 at Ser412. GADD34 depletion abolished the interaction between TAK1 and PP1, and it relieved PP1 overexpression-induced inhibition of TLRs signaling and proinflammatory cytokine production. In addition, knockdown of GADD34 significantly promotes TLR-induced TAK1 Ser412 phosphorylation, downstream NF-?B and MAPK activation, and proinflammatory cytokine production. Therefore, PP1, as a physiologic inhibitor, together with its regulatory subunit GADD34, tightly controls TLR-induced TAK1 Ser412 phosphorylation, preventing excessive activation of TLRs and protecting the host from overwhelmed inflammatory immune responses.
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Analysis of initial changes in the proteins of soybean root tip under flooding stress using gel-free and gel-based proteomic techniques.
J Proteomics
PUBLISHED: 02-15-2014
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Flooding has a severe negative effect on soybean cultivation in the early stages of growth. To obtain a better understanding of the response mechanisms of soybean to flooding stress, initial changes in root tip proteins under flooding were analyzed using two proteomic techniques. Two-day-old soybeans were treated with flooding for 3, 6, 12, and 24h. The weight of soybeans increased during the first 3h of flooding, but root elongation was not observed. Using gel-based and gel-free proteomic techniques, 115 proteins were identified in root tips, of which 9 proteins were commonly detected by both methods. The 71 proteins identified by the gel-free proteomics were analyzed by a hierarchical clustering method based on induction levels during the flooding, and the proteins were divided into 5 clusters. Additional interaction analysis of the proteins revealed that ten proteins belonging to cluster I formed the center of a protein interaction network. mRNA expression analysis of these ten proteins showed that citrate lyase and heat shock protein 70 were down-regulated, whereas calreticulin was up-regulated in initial phase of flooding. These results suggest that flooding stress to soybean induces calcium-related signal transduction, which might play important roles in the early responses to flooding.
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Uniform self-forming metallic network as a high-performance transparent conductive electrode.
Adv. Mater. Weinheim
PUBLISHED: 02-11-2014
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A transparent, conductive, and flexible electrode is demonstrated. It is based on an inexpensive and easily manufacturable metallic network formed by depositing metals onto a template film. This electrode shows excellent electro-optical properties, with the figure of merit ranging from 300 to 700, and transmittance from 82% (~4.3 ? sq(-1) ) to 45% (~0.5 ? sq(-1) ).
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Mitochondria and cytoplasmic male sterility in plants.
Mitochondrion
PUBLISHED: 02-09-2014
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Mitochondria are essential organelles in cells not only because they supply over 90% of the cell's energy but also because their dysfunction is associated with disease. Owing to the importance of mitochondria, there are many questions about mitochondria that must be answered. Cytoplasmic male sterility (CMS) is a mysterious natural phenomenon, and the mechanism of the origin of CMS is unknown. Despite successful utilization of CMS and restoration of fertility (Rf) in practice, the underlying mechanisms of these processes remain elusive. This review summarizes the genes involved in CMS and Rf, with a special focus on recent studies reporting the mechanisms of the CMS and Rf pathways, and concludes with potential working models.
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H3K36 histone methyltransferase Setd2 is required for murine embryonic stem cell differentiation toward endoderm.
Cell Rep
PUBLISHED: 02-04-2014
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Setd2 is known as a histone-H3K36-specific methyltransferase. However, its role in physiological function remains unclear. In this study, we show that Setd2 mainly regulates differentiation of murine embryonic stem cells (mESCs) toward primitive endoderm. Furthermore, we show that downregulated endoderm-related genes in Setd2(-/-) mESCs are associated with an aberrantly low level of Erk activity and that enforced expression of Fgfr3 can rescue the defective Erk pathway in Setd2(-/-) mESCs. Interestingly, the transcriptional initiation of Fgfr3 is directly regulated through histone H3K36me3 modification in its distal promoter region by Setd2. These results indicate that Setd2 controls the primitive endoderm differentiation of mESCs by regulating the Fgfr3-Erk signaling.
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Targeted amplification of delivery to cell surface receptors by dendrimer self-assembly.
Bioorg. Med. Chem. Lett.
PUBLISHED: 01-17-2014
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Nanometer-scale architectures assembled on cell surface receptors from smaller macromolecular constituents generated a large amplification of fluorescence. A targeted dendrimer was synthesized from a cystamine-core G4 PAMAM dendrimer, and contained an anti-BrE3 monoclonal antibody as the targeting group, several fluorophores and an average of 12 aldehyde moieties as complementary bio-orthogonal reactive sites for the covalent assembly. A cargo dendrimer, derived from a PAMAM G4 dendrimer, contained several fluorophores as the cargo for delivery and five hydrazine moieties as complimentary bio-orthogonal reactive sites. The system is designed to be flexible and allow for facile incorporation of a variety of targeting ligands.
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Interaction with Cu²? disrupts the RNA binding affinities of RNA recognition motif containing protein.
Biochem. Biophys. Res. Commun.
PUBLISHED: 01-07-2014
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The glycine-rich proteins (GRP) containing RNA recognition motifs (RRM) are involved in the regulation of transcriptional and/or post-transcriptional events. Previous studies have established that GRP162 plays an important role in the restoration of fertility in Honglian cytoplasmic male sterile (HL-CMS) rice. In this study, the ion binding properties of rGRP162 were tested by isothermal titration calorimetry (ITC) and electrophoretic mobility shift assay (EMSA) was performed to test the interaction. Circular dichroism (CD) was carried out to detect the alteration of secondary structure in the presence and absence of Cu(2+). Furthermore, two RRM containing proteins, AtRBP45A and AtRBP47A, were expressed to validate the interaction. Results showed Cu(2+) and Fe(3+) bound GRP162, whereas Ca(2+), Mn(2+), Mg(2+) and K(+) did not. EMSA confirmed that interaction with Cu(2+) interrupted the biological activity of GRP162 by disrupting the secondary structure of the protein based on the results of CD. Moreover, the RNA binding activities of rAtRBP45A and rAtRBP47A were also impaired in the presence of Cu(2+). Data suggest that Cu(2+) in excess may disrupt RNA-binding proteins containing RRM that are essential for post-transcriptional regulation and may impair the development of plants or animals.
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DNA methyltransferase 1/3a overexpression in sporadic breast cancer is associated with reduced expression of estrogen receptor-alpha/breast cancer susceptibility gene 1 and poor prognosis.
Mol. Carcinog.
PUBLISHED: 01-02-2014
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DNA methyltransferases (DNMTs), including DNMT1, 3a, and 3b, play an important role in the progression of many malignant tumors. However, it remains unclear whether expression of DNMTs is associated with the development of breast cancer. This study aimed to explore the clinical significance of DNMT proteins in sporadic breast cancer. We investigated the expression of DNMT1, 3a, and 3b in 256 breast cancer and 36 breast fibroadenoma, using immunohistochemistry. The expression of DNMT1 and 3a was significantly higher in breast cancer than in fibroadenoma. In breast cancer, the expression of DNMT1 was significantly correlated with lymph node metastasis (P?=?0.020), and the expression of DNMT3a and 3b was significantly correlated with advanced clinical stages (P?=?0.046 and 0.012, respectively). Overexpression of DNMT1/3a was correlated with promoter hypermethylation and reduced expression of ER? and BRCA1. The expression levels of DNMT1 or DNMT3a were associated with a significantly shorter DFS or OS in a subgroup of breast cancer patients (patients with the age ?50 years old, ER?-negative status, or HER2-postive status). The expression of DNMT1 or a combined expression of DNMT1 and 3a was associated with poor prognosis in patients who received chemotherapy and endocrine therapy, but not in patients who received chemotherapy alone. These findings suggest that DNMT1 and 3a may be involved in the progression and prognosis of sporadic breast cancer. © 2014 Wiley Periodicals, Inc.
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Two Metallothionein Genes in Oxya chinensis: Molecular Characteristics, Expression Patterns and Roles in Heavy Metal Stress.
PLoS ONE
PUBLISHED: 01-01-2014
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Metallothioneins (MTs) are small, cysteine-rich, heavy metal-binding proteins involved in metal homeostasis and detoxification in living organisms. In the present study, we cloned two MT genes (OcMT1 and OcMT2) from Oxya chinensis, analyzed the expression patterns of the OcMT transcripts in different tissues and at varying developmental stages using real-time quantitative PCR (RT-qPCR), evaluated the functions of these two MTs using RNAi and recombinant proteins in an E. coli expression system. The full-length cDNAs of OcMT1 and OcMT2 encoded 40 and 64 amino acid residues, respectively. We found Cys-Cys, Cys-X-Cys and Cys-X-Y-Z-Cys motifs in OcMT1 and OcMT2. These motifs might serve as primary chelating sites, as in other organisms. These characteristics suggest that OcMT1 and OcMT2 may be involved in heavy metal detoxification by capturing the metals. Two OcMT were expressed at all developmental stages, and the highest levels were found in the eggs. Both transcripts were expressed in all eleven tissues examined, with the highest levels observed in the brain and optic lobes, followed by the fat body. The expression of OcMT2 was also relatively high in the ovaries. The functions of OcMT1 and OcMT2 were explored using RNA interference (RNAi) and different concentrations and treatment times for the three heavy metals. Our results indicated that mortality increased significantly from 8.5% to 16.7%, and this increase was both time- and dose-dependent. To evaluate the abilities of these two MT proteins to confer heavy metal tolerance to E. coli, the bacterial cells were transformed with pET-28a plasmids containing the OcMT genes. The optical densities of both the MT-expressing and control cells decreased with increasing concentrations of CdCl2. Nevertheless, the survival rates of the MT-overexpressing cells were higher than those of the controls. Our results suggest that these two genes play important roles in heavy metal detoxification in O. chinensis.
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Discrepant expression of cytokines in inflammation- and age-related cataract patients.
PLoS ONE
PUBLISHED: 01-01-2014
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Inflammatory cataracts secondary to Behcet's disease (BD) or Vogt-Koyanagi-Harada disease (VKH) are thought to result from a pathological dysregulation of cytokines that is different from that of age-related (AR) cataracts. However, little is known about the function of cytokines in the development of inflammatory cataracts. The purpose of this study was to identify possible differences in cytokine expression in inflammation- and age-related cataract patients.
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Congenital cataract: prevalence and surgery age at Zhongshan Ophthalmic Center (ZOC).
PLoS ONE
PUBLISHED: 01-01-2014
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Congenital cataract (CC) is the primary cause of treatable childhood blindness. Population-based assessments of prevalence and surgery age of CC, which are critical for improving management strategies, have been unavailable in China until now. We conducted a hospital-based, cross-sectional study of the hospital charts of CC patients younger than 18 years old from January 2005 to December 2010 at Zhongshan Ophthalmic Center (ZOC) in Guangzhou, China. Residence, gender, age at surgery, hospitalization time, and the presence of other ocular abnormalities were extracted and statistically analyzed in different subgroups. The search identified 1314 patients diagnosed with CC from a total of 136154 hospitalizations, which accounted for 2.39% of all the cataract in-patients and 1.06% of the total in-patients over the six-year study period. Of the identified CC patients, 9.2% had ? 2 hospitalizations due to the necessity of additional surgeries, with a total ratio of boys to girls of 1.75 ? 1. Based on a subgroup analysis according to age, patients 2-6 years old constituted the highest proportion (29.22%) of all hospitalized CC patients, and those 13-18 years old constituted the lowest proportion (13.47%) of the total number. The average age at surgery was 27.62 ± 23.36 months, but CC patients ? 6 years old (especially ? 6 months old) became increasingly prevalent throughout the 6-year study period. A total of 276 cases (20.93%) of CC were associated with one or more other ocular abnormalities, the highest incidence rates were observed for exotropia (6.24%), nystagmus (6.16%), and refractive error (3.65%). In conclusion, CC patients accounted for 2.39% of all cataract in-patients in a review of 6 years of hospitalization charts from ZOC. The age at the time of surgery decreased over the 6-year study period, which probably reflects the continuing improvement of public awareness of children's eye care in China.
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A 20-amino-acid deletion in the neuraminidase stalk and a five-amino-acid deletion in the NS1 protein both contribute to the pathogenicity of H5N1 avian influenza viruses in mallard ducks.
PLoS ONE
PUBLISHED: 01-01-2014
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Since 2003, H5N1-subtype avian influenza viruses (AIVs) with both a deletion of 20 amino acids in the stalk of the neuraminidase (NA) glycoprotein (A-) and a deletion of five amino acids at positions 80 to 84 in the non-structural protein NS1 (S-) have become predominant. To understand the influence of these double deletions in the NA and NS1 proteins on the pathogenicity of H5N1-subtype AIVs, we selected A/mallard/Huadong/S/2005 as a parental strain to generate rescued wild-type A-S- and three variants (A-S+ with a five-amino-acid insertion in the NS1 protein, A+S- with a 20-amino-acid insertion in the NA stalk, and A+S+ with insertions in both NA and NS1 proteins) and evaluated their biological characteristics and virulence. The titers of the AIVs with A- and/or S- replicated in DEF cells were higher than that of A+S+, and the A-S- virus exhibited a replication predominance when co-infected with the other variants in DEF cells. In addition, A-S- induced a more significant increase in the expression of immune-related genes in peripheral blood mononuclear cells of mallard ducks in vitro compared with the other variants. Furthermore, an insertion in the NA and/or NS1 proteins of AIVs resulted in a notable decrease in virulence in ducks, as determined by intravenous pathogenicity index, and the two insertions exerted a synergistic effect on the attenuation of pathogenicity in ducks. In addition, compared with A+S+ and A+S-, the A-S+ and A-S- viruses that were introduced via the intranasal inoculation route exhibited a faster replication ability in the lungs of ducks. These data indicate that both the deletions in the NA stalk and the NS1 protein contribute to the high pathogenicity of H5N1 AIVs in ducks.
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Selected lactic acid-producing bacterial isolates with the capacity to reduce Salmonella translocation and virulence gene expression in chickens.
PLoS ONE
PUBLISHED: 01-01-2014
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Probiotics have been used to control Salmonella colonization/infection in chickens. Yet the mechanisms of probiotic effects are not fully understood. This study has characterized our previously-selected lactic acid-producing bacterial (LAB) isolates for controlling Salmonella infection in chickens, particularly the mechanism underlying the control.
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Near-infrared fluorescent probes in cancer imaging and therapy: an emerging field.
Int J Nanomedicine
PUBLISHED: 01-01-2014
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Near-infrared fluorescence (NIRF) imaging is an attractive modality for early cancer detection with high sensitivity and multi-detection capability. Due to convenient modification by conjugating with moieties of interests, NIRF probes are ideal candidates for cancer targeted imaging. Additionally, the combinatory application of NIRF imaging and other imaging modalities that can delineate anatomical structures extends fluorometric determination of biomedical information. Moreover, nanoparticles loaded with NIRF dyes and anticancer agents contribute to the synergistic management of cancer, which integrates the advantage of imaging and therapeutic functions to achieve the ultimate goal of simultaneous diagnosis and treatment. Appropriate probe design with targeting moieties can retain the original properties of NIRF and pharmacokinetics. In recent years, great efforts have been made to develop new NIRF probes with better photostability and strong fluorescence emission, leading to the discovery of numerous novel NIRF probes with fine photophysical properties. Some of these probes exhibit tumoricidal activities upon light radiation, which holds great promise in photothermal therapy, photodynamic therapy, and photoimmunotherapy. This review aims to provide a timely and concise update on emerging NIRF dyes and multifunctional agents. Their potential uses as agents for cancer specific imaging, lymph node mapping, and therapeutics are included. Recent advances of NIRF dyes in clinical use are also summarized.
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Association of TNP2 gene polymorphisms of the bta-miR-154 target site with the semen quality traits of Chinese Holstein bulls.
PLoS ONE
PUBLISHED: 01-01-2014
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Transition protein 2 (TNP2) participates in removing nucleohistones and the initial condensation of spermatid nucleus during spermiogenesis. This study investigated the relationship between the variants of the bovine TNP2 gene and the semen quality traits of Chinese Holstein bulls. We detected three single nucleotide polymorphisms (SNPs) of the TNP2 gene in 392 Chinese Holstein bulls, namely, g.269 G>A (exon 1), g.480 C>T (intron 1), and g.1536 C>T (3'-UTR). Association analysis showed that the semen quality traits of the Chinese Holstein bulls was significantly affected by the three SNPs. The bulls with the haplotypic combinations H6H4, H6H6, and H6H8 had higher initial semen motility than those with the H7H8 and H8H4 haplotypic combinations (P<0.05). SNPs in the microRNA (miRNA) binding region of the TNP2 gene 3'-UTR may have contributed to the phenotypic differences. The phenotypic differences are caused by the altered expression of the miRNAs and their targets. Bioinformatics analysis predicted that the g.1536 C>T site in the TNP2 3'-UTR is located in the bta-miR-154 binding region. The quantitative real-time polymerase chain reaction results showed that the TNP2 mRNA relative expression in bulls with the CT and CC genotypes was significantly higher than those with the TT genotype (P<0.05) in the g.1536 C>T site. The luciferase assay also indicated that bta-miR-154 directly targets TNP2 in a murine Leydig cell tumor cell line. The SNP g.1536 C>T in the TNP2 3'-UTR, which altered the binding of TNP2 with bta-miR-154, was found to be associated with the semen quality traits of Chinese Holstein bulls.
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Widely tunable all-fiber optical parametric oscillator based on a photonic crystal fiber pumped by a picosecond ytterbium-doped fiber laser.
Opt Lett
PUBLISHED: 12-11-2013
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We report on a fully fiber-integrated widely tunable optical parametric oscillator based on a photonic crystal fiber pumped by a picosecond ytterbium-doped fiber laser. The output wavelength of the oscillator can be continuously tuned from 898 to 1047 nm and from 1086 to 1277 nm, which is as wide as 340 nm. In particular, a larger Raman gain peak is simultaneously observed when the pump wavelength is far from the zero-dispersion wavelength in the normal-dispersion regime. The bandwidth of the output of the oscillator can be tuned by slightly adjusting the pump power.
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Highly Efficient and Versatile Synthesis of Lactams and N-Heterocycles via Al(OTf)3-Catalyzed Cascade Cyclization and Ionic Hydrogenation Reactions.
Org. Lett.
PUBLISHED: 12-06-2013
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The discovery and development of an efficient and versatile method for the synthesis of N-substituted lactams is described. Pyrrolindinones, piperidones, and structurally related heterocycles were formed by Al(OTf)3-catalyzed cascade cyclization and ionic hydrogenation reactions of corresponding nitrogen substituted ketoamides in good yields.
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Large-Scale Development of Gene-Associated Single-Nucleotide Polymorphism Markers for Molluscan Population Genomic, Comparative Genomic, and Genome-Wide Association Studies.
DNA Res.
PUBLISHED: 11-25-2013
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Mollusca is the second most diverse group of animals in the world. Despite their perceived importance, omics-level studies have seldom been applied to this group of animals largely due to a paucity of genomic resources. Here, we report the first large-scale gene-associated marker development and evaluation for a bivalve mollusc, Chlamys farreri. More than 21 000 putative single-nucleotide polymorphisms (SNPs) were identified from the C. farreri transcriptome. Primers and probes were designed and synthesized for 4500 SNPs, and 1492 polymorphic markers were successfully developed using a high-resolution melting genotyping platform. These markers are particularly suitable for population genomic analysis due to high polymorphism within and across populations, a low frequency of null alleles, and conformation to neutral expectations. Unexpectedly, high cross-species transferability was observed, suggesting that the transferable SNPs may largely represent ancestral genetic variations that have been preserved differentially among subfamilies of Pectinidae. Gene annotations were available for 73% of the markers, and 65% could be anchored to the recently released Pacific oyster genome. Large-scale association analysis revealed key candidate genes responsible for scallop growth regulation, and provided markers for further genetic improvement of C. farreri in breeding programmes.
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Dibenzoheptazethrene Isomers with Different Biradical Characters: An Exercise of Clars Aromatic Sextet Rule in Singlet Biradicaloids.
J. Am. Chem. Soc.
PUBLISHED: 11-20-2013
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Clars aromatic sextet rule has been widely used for the prediction of the reactivity and stability of polycyclic aromatic hydrocarbons with a closed-shell electronic configuration. Recent advances in open-shell biradicaloids have shown that the number of aromatic sextet rings plays an important role in determination of their ground states. In order to test the validity of this rule in singlet biradicaloids, the two soluble and stable dibenzoheptazethrene isomers DBHZ1 and DBHZ2 were prepared by different synthetic approaches and isolated in crystalline form. These two molecules have different numbers of aromatic sextet rings in their respective biradical resonance forms and thus are expected to exhibit varied singlet biradical character. This assumption was verified by different experimental methods, including nuclear magnetic resonance (NMR), electron spin resonance (ESR), superconducting quantum interference device (SQUID), steady-state and transient absorption spectroscopy (TA), and X-ray crystallographic analysis, assisted by unrestricted symmetry-broken density functional theory (DFT) calculations. DBHZ2, with more aromatic sextet rings in the biradical form, was demonstrated to possess greater biradical character than DBHZ1; as a result, DBHZ2 exhibited an intense one-photon absorption (OPA) in the near-infrared region (?abs(max) = 804 nm) and a large two-photon absorption (TPA) cross-section (?((2))max = 2800 GM at 1600 nm). This investigation together with previous studies indicates that Clars aromatic sextet rule can be further extended to the singlet biradicaloids to predict their ground states and singlet biradical characters.
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An all-fiber continuously time-dispersion-tuned picosecond optical parametric oscillator at 1 ?m region.
Opt Express
PUBLISHED: 10-24-2013
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We report the experimental demonstration of a fully fiber-integrated picosecond optical parametric oscillator. The gain is provided by a 50-meters homemade photonic crystal fiber in the ring cavity. A time-dispersion-tuned technique is used to allow the oscillator to select the oscillating wavelength adaptively and synchronize with the pump pulse train. The output wavelength of the oscillator can be continuously tuned from 988 to 1046 nm and from 1085 to 1151 nm by adjusting the pump wavelength and the time-dispersion-tuned technique simultaneously.
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Mesoporous titanium zirconium oxide nanospheres with potential for drug delivery applications.
ACS Appl Mater Interfaces
PUBLISHED: 10-22-2013
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Mesoporous titanium zirconium (TiZr) oxide nanospheres with variable Ti to Zr ratios were synthesized using sol-gel chemistry followed by solvothermal treatment. These oxide nanospheres exhibited similar diameters (~360 nm), high surface areas (from 237 ± 2 to 419 ± 4 m(2) g(-1)), and uniform pore diameters (~3.7 nm). Three drugs, ibuprofen, dexamethasone, and erythromycin, were loaded into the TiZr oxide nanospheres. The TiZr oxide nanospheres exhibited a high loading capacity, up to 719 mg g(-1), and sustained release profiles in phosphate buffered saline (PBS) at pH 7.4. The mesoporous TiZr oxide nanospheres also exhibited hydrolytic stability, as evidenced by the retention of the integrity of the mesostructures after drug release in PBS for 21 days.
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One-pot synthesis of 4-methylisoquinolines via a sequential Pd-catalyzed Heck reaction and intramolecular cyclization.
Org. Biomol. Chem.
PUBLISHED: 09-26-2013
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An efficient, one-pot synthesis of 4-methylisoquinolines via a cascade Pd-catalyzed Heck reaction, intramolecular cyclization and isomerization has been developed. This reaction has a wide range of substrates with various functional groups, and the corresponding products have been obtained in good yields.
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Cooperation behavior between heterogeneous cations in hybrid batteries.
Chem. Commun. (Camb.)
PUBLISHED: 09-16-2013
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A cooperative behavior of Zn(2+) and Li(+) to conduct charges in a Zn-LiFePO4 battery is disclosed. When Li(+) dissolves into the electrolyte, Zn(2+) would deposit, and vice versa. In light of this cooperative behavior, the battery can be viewed as a super hybrid system, which combines the strong points of Zn-air battery, lithium-ion battery and redox-flow cell.
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High efficiency solar cells as fabricated by Sb2S3-modified TiO2 nanofibrous networks.
ACS Appl Mater Interfaces
PUBLISHED: 08-27-2013
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High-efficiency hybrid solar cells (HSCs) based on electrospun titanium dioxide (TiO2) nanofibers plus poly(3-hexylthiophene) (P3HT) are fabricated by means of both the pretreatment using tetrahydrofuran (THF) vapor and the surface modification using n-type antimony chalcogenide (Sb2S3) on the TiO2 nanofibrous networks. It is revealed that the THF pretreatment not only reinforces the interfacial physical contact but also suppresses the interfacial recombination. The Sb2S3 modification improves the light absorption and charge transfer. Given that the active layer of the HSCs is as thin as 300 nm, it is demonstrated that the power conversion efficiency (PCE) is enhanced over 175%, exhibiting a PCE of 2.32%.
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Spatiotemporal expression of KHSRP modulates Schwann cells and neuronal differentiation after sciatic nerve injury.
Int. J. Biochem. Cell Biol.
PUBLISHED: 08-26-2013
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K-homology splicing regulator protein (KHSRP), a multifunctional RNA-binding protein, was originally thought to primarily control mRNA decay. KHSRP was shown to be involved in p38MAPK, NF-?B and the JAK2-STAT-1a pathways. Besides, KHSRP regulated neuronal localization of beta-actin and microtubule-associated protein 2 (MAP2) mRNAs, respectively. However, the expression and roles of KHSRP in peripheral system lesions and repair are still unknown. In our study, we found that KHSRP levels were relatively higher in the crushed sciatic nerves, significantly reached a highest level at day 5. Spatially, we observed that KHSRP had a major colocalization with Schwann cells (SCs) and neurons. KHSRP was connected with promyelinating SCs marker. KHSRP promoted the decay of beta-catenin (?-catenin) mRNA which was inactivated by PI3K-AKT signaling. We doubted that KHSRP might participate in Schwann cells differentiation by regulation of ?-catenin mRNA decay. In vitro, in cyclic adenosine monophosphate (cAMP)-induced Schwann cells differentiation system, we detected the increased KHSRP in cytoplasm and decreased ?-catenin at protein and mRNA level. In differentiation model of rat pheochromocytoma cells (PC12) induced by nerve growth factor (NGF) and primary dorsal root ganglion (DRG) cell culture, KHSRP also acted on neuronal differentiation. Specially, KHSRP-specific siRNA-transfected cells did not show morphological change, which was similar to ?-catenin overexpressed SCs. During SC/neuron co-cultures, KHSRP was transported to cytoplasm and involved in SCs myelination. In conclusion, we speculated that KHSRP was involved in SCs and neuronal differentiation by inducing ?-catenin mRNA decay.
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Biomechanical comparison of posterior lumbar interbody fusion and transforaminal lumbar interbody fusion by finite element analysis.
Neurosurgery
PUBLISHED: 08-13-2013
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The transforaminal lumbar interbody fusion (TLIF) procedure may reduce many of the risks and limitations associated with posterior lumbar interbody fusion (PLIF). However, little is known about the biomechanical difference between PLIF and TLIF.
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Stimulated leaf dark respiration in tomato in an elevated carbon dioxide atmosphere.
Sci Rep
PUBLISHED: 08-05-2013
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It is widely accepted that leaf dark respiration is a determining factor for the growth and maintenance of plant tissues and the carbon cycle. However, the underlying effect and mechanism of elevated CO2 concentrations ([CO2]) on dark respiration remain unclear. In this study, tomato plants grown at elevated [CO2] showed consistently higher leaf dark respiratory rate, as compared with ambient control plants. The increased respiratory capacity was driven by a greater abundance of proteins, carbohydrates, and transcripts involved in pathways of glycolysis carbohydrate metabolism, the tricarboxylic acid cycle, and mitochondrial electron transport energy metabolism. This study provides substantial evidence in support of the concept that leaf dark respiration is increased by elevated [CO2] in tomato plants and suggests that the increased availability of carbohydrates and the increased energy status are involved in the increased rate of dark respiration in response to elevated [CO2].
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Molecular evolution of the HD-ZIP I gene family in legume genomes.
Gene
PUBLISHED: 07-23-2013
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Homeodomain leucine zipper I (HD-ZIP I) genes were used to increase the plasticity of plants by mediating external signals and regulating growth in response to environmental conditions. The way genomic histories drove the evolution of the HD-ZIP I family in legume species was described; HD-ZIP I genes were searched in Lotus japonicus, Medicago truncatula, Cajanus cajan and Phaseolus vulgaris, and then divided into five clades through phylogenetic analysis. Microsynteny analysis was made based on genomic segments containing the HD-ZIP I genes. Some pairs turned out to conform with syntenic genome regions, while others corresponded to those that were inverted, expanded, or contracted after the divergence of legumes. Besides, we dated their duplications by Ks analysis and demonstrated that all the blocks were formed after the monocot-dicot split; we observed Ka/Ks ratios representing strong purifying selections in the four legume species which might have been followed by gene loss and rearrangement.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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