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Find video protocols related to scientific articles indexed in Pubmed.
Calculating pressure in polymer lattice simulations.
Soft Matter
PUBLISHED: 11-20-2014
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We propose several novel methods for calculating the bulk pressure in polymer lattice simulations. Our first method combines chain insertion/deletion with Wang-Landau - Optimized Ensemble sampling in the space of number of chains n, which is very efficient and accurate at low to intermediate polymer volume fractions ? (e.g., ?0.7). We then propose two methods in canonical-ensemble simulations to efficiently and accurately calculate the bulk pressure at high ? where chain insertion/deletion becomes inefficient. Finally, combining these methods leads to complete thermodynamics over the entire range of continuous and exact ?-values with negligible finite-size effects. We also analyze in detail the error caused by the cut-off in n-space.
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Adjuvant effects of recombinant giant panda (Ailuropoda melanoleuca) IL-18 on the canine distemper disease vaccine in mice.
J. Vet. Med. Sci.
PUBLISHED: 11-18-2014
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Canine distemper virus (CDV) is a morbillivirus known to cause morbidity and mortality in a broad range of animals. Giant pandas (Ailuropoda melanoleuca), especially captive ones, are susceptible to natural infection with CDV. Interleukin-18 (IL-18) is a powerful adjuvant molecule that can enhance the development of antigen-specific immunity and vaccine efficacy. In this study, a giant panda IL-18 gene eukaryotic expression plasmid (pcAmIL-18) was constructed. Female BALB/c mice were muscularly inoculated with the plasmids pcAmIL-18, pcDNA3.1 and PBS, respectively. They were subsequently injected with an attenuated CDV vaccine for dogs, and the induced humoral and cellular responses were evaluated. The results showed that pcAmIL-18 remarkably improved the level of specific antibody, IFN-? and IL-2 in mice sera, the T lymphocyte proliferation index and the percentage of CD4(+) and CD8(+) cells. These data indicated that pcAmIL-18 is a potential adjuvant that promotes specific immunity.
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Mediation of smoking abstinence self-efficacy on the association of nicotine dependence with smoking cessation.
Eur J Public Health
PUBLISHED: 11-15-2014
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The nicotine dependence (ND) has negative and smoking abstinence self-efficacy (SASE) has positive effects on successful smoking cessation, but scant data is now available for what is the mediating role of SASE on the relationship between ND and successful smoking cessation. The aim of this study was to assess the abovementioned mediation.
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Enantioselective Analysis and Dissipation of Triazole Fungicide Penconazole in Vegetables by Liquid Chromatography-Tandem Mass Spectrometry.
J. Agric. Food Chem.
PUBLISHED: 11-07-2014
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Penconazole is a typical triazole fungicide, which is commonly used to control powdery mildew in vineyard and vegetable field. In this study, the enantioselective dissipation of penconazole in cucumber, tomato, head cabbage, and pakchoi was investigated by field experiments. A sensitive method for enantiomeric analysis of penconazole was established on the basis of the buffered QuEChERS sample preparation technique followed by reverse-liquid chromatography equipped with a TSQ Discovery triple quadrupole mass spectrometer and a Lux Cellulose-2 chiral column. Methanol and 2 mM ammonium acetate buffer solution containing 0.1% formic acid (70:30, v/v) were used as mobile phase at a 0.2 mL L(-1) flow rate isocratic elution. The linearity, recovery, and precision of this method were also evaluated. Finally, the results of this study demonstrated that enantioselective dissipation occurred in head cabbage and pakchoi, with the preferential degradation of (-)-penconazole, and resulting in an enrichment of the (+)-penconazole residue in the two vegetables. However, the enantioselective behavior was not observed in cucumber and tomato. More importantly, this is the first report of enantioselective behavior of penconazole, and the result may provide useful information for the risk evaluation of penconazole in food and environmental safety.
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In situ labelling chemistry of respiratory syncytial viruses by employing the biotinylated host-cell membrane protein for tracking the early stage of virus entry.
Chem. Commun. (Camb.)
PUBLISHED: 11-06-2014
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An in situ labelling strategy was proposed to produce quantum dot-labelled respiratory syncytial viruses (RSVs) by incorporating the biotinylated membrane protein of the host cells into mature virions, followed by conjugation with streptavidin modified quantum dots (SA-QDs), which has the advantages such as convenience, efficiency and minor influence on viral infectivity and thus could be successfully applied to track the early stage of virus entry.
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Variations in the Natural (15)N Abundance of Brassica chinensis Grown in Uncultivated Soil Affected by Different Nitrogen Fertilizers.
J. Agric. Food Chem.
PUBLISHED: 11-06-2014
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To further investigate the method of using ?(15)N as a marker for organic vegetable discrimination, the effects of different fertilizers on the ?(15)N in different growing stages of Brassica chinensis (B. chinensis) grown in uncultivated soil were investigated with a pot experiment. B. chinensis was planted with uncultivated soil and different fertilizer treatments and then harvested three times in three seasons consecutively. For the spring experiments in the years of 2011 and 2012, the ?(15)N value of B. chinensis, which increased due to organic manure application and decreased due to chemical fertilizer application, was significantly different (p < 0.05) with manure treatment and chemical treatment. The ?(15)N value of vegetables varied among three growing stages and ranged from +8.6‰ to +11.5‰ for the control, from +8.6‰ to +12.8‰ for the compost chicken manure treatment, from +2.8‰ to +7.7‰ for the chemical fertilizer urea treatment, and from +7.7‰ to +10.9‰ for the compost-chemical fertilizer treatment. However, the ?(15)N values observed in the autumn experiment of 2011 without any fertilizer application increased ranging from +13.4‰ to +15.4‰, + 11.2‰ to +17.7‰, +10.7‰ to +17.1‰, and +10.6‰ to +19.1‰, respectively, for the same treatments mentioned above. This result was not significantly different between manure treatment and chemical treatment. The ?(15)N values of soil obtained in the spring of 2011 during three growing stages were slightly affected by fertilizers and varied in the range of +1.6‰ to +2.5‰ for CK, +4.7‰ to +6.5‰ for compost treatment, +2.1‰ to +2.4‰ for chemical treatment, and +2.7‰ to +4.6‰ for chemical-compost treatment, respectively. High ?(15)N values of B. chinensis were observed in these experiments, which would be useful to supplement a ?(15)N database for discriminating organic vegetables. Although there was a significant difference between manure treatment and chemical treatment, it was still difficult to discriminate whether a labeled organic vegetable was really grown without chemical fertilizer just with a fixed high ?(15)N value, especially for the vegetables planted simultaneously with chemical and compost fertilizer.
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Copper-Mediated ?-Trifluoromethylation of N-Phenylcinnamamides Coupled with Dearomatization: Access to Trifluoromethylated 1-Azaspiro[4.5]decanes.
Org. Lett.
PUBLISHED: 11-04-2014
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Copper-mediated intramolecular trifluoromethylation of N-phenylcinnamamides coupled with cyclization and dearomatization was used to construct various trifluoromethylated 1-azaspiro[4.5]decanes in moderate to high yields and with excellent regioselectivity and diastereoselectivity.
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Comparison of Clinical Outcomes of Anterior Versus Posterior Surgery in Treating Multi-segmental Cervical Degeneration.
Cell Biochem. Biophys.
PUBLISHED: 10-22-2014
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The purpose of this study is to compare clinical outcome of different surgical methods in treating multi-segmental cervical degeneration. Three hundred and sixty eight patients with multi-segmental cervical degeneration were retrospectively selected and divided into two groups with 184 cases in each based on different surgical methods: one group accepted surgeries from anterior surgical approach and the other group accepted surgeries from posterior surgical approach. Perioperative parameters including operative time, intraoperative blood loss and length of stay were compared between two groups. Patients were followed up after 1 week, 6 month, 10 months and 1 year after surgery. Cervical X-ray was retaken, and Japanese orthopaedic association (JOA) scores, neck disability index (NDI ) scores and numerical pain rating scale (NPRS ) scores were obtained for comparison. Samples from cervical disc were processed to detect cytokines level including IL-1, IL-6, TNF-? and MMP-3. Perioperative parameters including operative time, intraoperative blood loss and length of stay showed no significant difference (P < 0.05) between the two groups. JOA score, NDI scores and NPRS scores, all showed a significant improvement after the surgery in both methods, however, when comparing the two methods, no significant difference was found between two groups (P > 0.05), except that NDI scores in anterior surgical approach group were significantly lower than posterior surgical approach group at different follow-up time points (P < 0.05). The average height of fused vertebral bodies after surgery in two groups was significantly different from pre-operative height (P < 0.05), and angle loss in posterior surgical approach group was significantly higher than anterior surgical approach (P < 0.05), which was statistically different. Cytokines including IL-1, IL-6, TNF-? and MMP-3 in two groups had no statistical difference (P > 0.05). Anterior approach surgery and posterior approach surgery are both effective methods to treat multi-segmental cervical degeneration. Anterior approach had better clinical outcomes within 1-year follow-up.
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Chlorpyrifos Residual Behaviors in Field Crops and Transfers during Duck Pellet Feed Processing.
J. Agric. Food Chem.
PUBLISHED: 10-14-2014
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Chlorpyrifos is a widely used organophosphorus pesticide in agricultural crops (including food) and animal feeds in China, resulting in heavy contamination. Many studies have focused on the food-processing effects on chlorpyrifos removal, but sufficient information is not observed for feed-processing steps. Here, chlorpyrifos residual behaviors in field crops and its transfers in duck pellet feed-processing steps were evaluated. In field trials, the highest residues for rice grain, shelled corn, and soybean seed were 12.0, 0.605, and 0.220 mg/kg, respectively. Residues of all rice grain and about half of shelled corn exceeded the maximum residue limits (MRLs) of China, and five soybean seeds exceeded the MRL of China. Chlorpyrifos residue was reduced 38.2% in brown rice after the raw rice grain was hulled. The residue in bran increased 71.2% after milling from brown rice. During the squashing step, the residue reduced 73.8% in soybean meal. The residues reduced significantly (23.7-36.8%) during the process of granulating for rice, maize, and soybean products. Comparatively, the grinding process showed only limited influence on chlorpyrifos removal (<10%). The residues of duck pellet feeds produced from highly contaminated raw materials of this study were 1.01 mg/kg (maize-soybean feed) and 3.20 mg/kg (rice-soybean feed), which were much higher than the generally accepted value (>0.1 mg/kg) for animal feeding. Chlorpyrifos residues were removed significantly by processing steps of pellet feeds, but the residue of raw materials was the determining factor for the safety of duck feeding.
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[Lack of association of COMT Val158Met polymorphism with attention and executive function in patients with schizophrenia].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 10-10-2014
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To explore the association of a functional polymorphism Val158Met of COMT gene and attention and executive function in first-episode treatment-naive patients with schizophrenia and healthy controls.
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Health risk assessment of Chinese consumers to nickel via dietary intake of foodstuffs.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess
PUBLISHED: 10-07-2014
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A quantitative risk assessment was carried out to characterise the health risk from nickel (Ni) via dietary exposure for Chinese consumers. Ni contamination in foods was investigated by conducting a survey and a literature review. The daily diet of the public was categorised into nine food groups and the consumption data for each group were obtained from a nationwide survey. Deterministic and probabilistic methods were applied to calculate the target hazard quotients (THQs) by comparing the estimated dietary Ni intake with respect to the tolerable daily intake (TDI). The average estimated daily Ni intake (?g kg(-1) bw day(-1)) for men, women, 2-3-year-old children and 4-17-year-old children were 7.2, 7.3, 17.1 and 10.0, respectively. The consumption of cereals, beans, vegetables and marine products contributed significantly to the total daily intake of Ni. The mean THQ values (95% confidence interval) and the probability of dietary Ni exposure higher than the TDI were 0.60 (0.58-0.62) and 8.2% for men, 0.61 (0.59-0.63) and 8.4% for women, 1.35 (1.32-1.39) and 72.0% for 2-3-year-old children, and 0.87 (0.82-0.91) and 28.5% for 4-17-year-old children, respectively. This study showed a potential health risk from Ni via dietary exposure for Chinese consumers, especially among children.
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Water stress enhances expression of genes encoding plastid terminal oxidase and key components of chlororespiration and alternative respiration in soybean seedlings.
Z. Naturforsch., C, J. Biosci.
PUBLISHED: 10-01-2014
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Plastid terminal oxidase (PTOX) is a plastid-localized plastoquinone (PQ) oxidase in plants. It functions as the terminal oxidase of chlororespiration, and has the potential ability to regulate the redox state of the PQ pool. Expression of the PTOX gene was up-regulated in soybean seedlings after exposure to water deficit stress for 6 h. Concomitantly expression of the NDH-H gene, encoding a component of the NADPH dehydrogenase (NDH) complex which is a key component of both chlororespiration and NDH-dependent cyclic electron transfer (CET), was also up-regulated. Transcript levels of the proton gradient regulation (PGR5) gene, which encodes an essential component of the PGR5-dependent CET, were not affected by water stress, while the expression of the alternative oxidase (AOX1) gene, which encodes a terminal oxidase of alternative respiration in mitochondria, was also up-regulated under water stress. Therefore, our results indicate that water stress induced the up-regulation of genes encoding key components of chlororespiration and alternative respiration. Transcript levels of the AOX1 gene began to increase in response to water stress before those of PTOX suggesting that alternative respiration may react faster to water stress than chlororespiration.
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Contingent negative variation in patients with deficit schizophrenia or bipolar I disorder with psychotic features: Measurement and correlation with clinical characteristics.
Nord J Psychiatry
PUBLISHED: 09-30-2014
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Background: Schizophrenia is a highly heterogeneous disease. Event-related potentials have been regarded to establish intermediate phenotypes of schizophrenia. Our previous study found that patients with deficit schizophrenia (DS) are relatively homogeneous and show a significantly longer onset latency of contingent negative variation (CNV) expectancy wave. Aims: To further examine CNV in patients with first-episode and drug-naïve DS or bipolar I disorder (BP I) with psychotic features, and also investigate correlations between CNV and clinical characteristics in DS and BP I. Method: We elicited a CNV using an alarm (S1)-imperative (S2) paradigm in 30 DS patients or 33 BP I with psychotic features as well as 40 healthy controls. Results: CNV amplitude was significantly smaller and reaction time significantly longer in the DS and BP I groups than in healthy controls. Post-imperative negative variation (PINV) interval was significantly shorter in the DS group than in healthy controls. The onset latency of CNV expectancy wave was significantly longer and PINV area significantly smaller in the DS group than in the other groups. In the DS group, CNV amplitude and PINV interval correlated negatively with the subscale of negative symptoms on the Positive and Negative Syndrome Scale (PANSS); CNV amplitude also correlated negatively with disease duration. In the BP I group, CNV amplitude and reaction time showed no correlation with clinical features. Conclusions: CNV amplitude is a common trait marker for psychosis. The onset latency of CNV expectancy wave appears to be a specific trait marker and may be used to identify candidate genes for DS.
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Liver-directed gene therapy corrects cardiovascular lesions in feline mucopolysaccharidosis type I.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 09-29-2014
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Patients with mucopolysaccharidosis type I (MPS I), a genetic deficiency of the lysosomal enzyme ?-l-iduronidase (IDUA), exhibit accumulation of glycosaminoglycans in tissues, with resulting diverse clinical manifestations including neurological, ocular, skeletal, and cardiac disease. MPS I is currently treated with hematopoietic stem cell transplantation or weekly enzyme infusions, but these therapies have significant drawbacks for patient safety and quality of life and do not effectively address some of the most critical clinical sequelae, such as life-threatening cardiac valve involvement. Using the naturally occurring feline model of MPS I, we tested liver-directed gene therapy as a means of achieving long-term systemic IDUA reconstitution. We treated four MPS I cats at 3-5 mo of age with an adeno-associated virus serotype 8 vector expressing feline IDUA from a liver-specific promoter. We observed sustained serum enzyme activity for 6 mo at ?30% of normal levels in one animal, and in excess of normal levels in three animals. Remarkably, treated animals not only demonstrated reductions in glycosaminoglycan storage in most tissues, but most also exhibited complete resolution of aortic valve lesions, an effect that has not been previously observed in this animal model or in MPS I patients treated with current therapies. These data point to clinically meaningful benefits of the robust enzyme expression achieved with hepatic gene transfer that extend beyond the economic and quality of life advantages over lifelong enzyme infusions.
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Polyethylenimine Facilitated Ethyl Cellulose for Hexavalent Chromium Removal with a Wide pH Range.
ACS Appl Mater Interfaces
PUBLISHED: 09-25-2014
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Ethyl cellulose (EC) composites modified with 20.0 wt % polyethylenimine (PEI) (PEI/ECs) demonstrated effective hexavalent chromium, [Cr(VI)], removal from solutions with a wide pH range. For example, 4.0 mg/L Cr(VI) solution with a pH below 3.0 was completely purified by 3.0 g/L PEI/ECs within 5 min, much faster than the as-received EC (2 h) and activated carbon (several hours). These PEI/ECs adsorbents has overcome the low pH limitation of Cr(VI) removal; for example, 4.0 mg/L Cr(VI) solution with a pH of 11.0 was completely purified within 15 min. These adsorbents followed chemical adsorption as revealed from the pseudo-second-order kinetic study. These PEI/ECs following the isotherm Langmuir model have a maximum adsorption capacity of 36.8 mg/g, much higher than pure EC (12 mg/g), tetrabutylammonium-modified celluloses (16.67 mg/g), and magnetic carbon (16 mg/g). The reduction of Cr(VI) to Cr(III) by the oxidation of amine groups and hydroxyl groups of PEI/ECs was verified as the main mechanism for the Cr(VI) removal.
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Dlg5 regulates dendritic spine formation and synaptogenesis by controlling subcellular N-cadherin localization.
J. Neurosci.
PUBLISHED: 09-19-2014
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Most excitatory synapses in the mammalian brain are formed on dendritic spines, and spine density has a profound impact on synaptic transmission, integration, and plasticity. Membrane-associated guanylate kinase (MAGUK) proteins are intracellular scaffolding proteins with well established roles in synapse function. However, whether MAGUK proteins are required for the formation of dendritic spines in vivo is unclear. We isolated a novel disc large-5 (Dlg5) allele in mice, Dlg5(LP), which harbors a missense mutation in the DLG5 SH3 domain, greatly attenuating its ability to interact with the DLG5 GUK domain. We show here that DLG5 is a MAGUK protein that regulates spine formation, synaptogenesis, and synaptic transmission in cortical neurons. DLG5 regulates synaptogenesis by enhancing the cell surface localization of N-cadherin, revealing a key molecular mechanism for regulating the subcellular localization of this cell adhesion molecule during synaptogenesis.
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[Endemic situation and control progress of taeniasis in western China].
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi
PUBLISHED: 09-17-2014
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Taeniasis, caused by Taenia species, is one of the common zoonoses in China, particularly in the western region of China. Up to now, not enough attention has been given in the high prevalence and high burden of the diseases. In order to study the endemic patterns and control strategies of taeniasis, a series of epidemiological investigations, molecular researches and pilot control activities have been conducted in recent years. This paper reviews the relevant publications in taeniasis research over the last 10 years.
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[Response of photosynthesis traits of dominant plant species to different light regimes in the secondary forest in the area of Qiandao Lake, Zhejiang, China].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 09-17-2014
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To understand the mechanisms driving community succession in the secondary forest surrounding Qiandao Lake, Zhejiang, China, we investigated seasonal dynamics of the diurnal variations of net photosynthetic rates, their responses to both light and CO2, and chlorophyll fluorescence parameters of four dominant plant species, i. e., Pinus massoniana, Castanopsis sclerophylla, Lithocarpus glaber and Cyclobalanopsis glauca in three natural light habitats, i. e., gap, edge and understory. In the three different light regimes, the daily mean values of the net photosynthetic rate (Pn) of P. massoniana and C. sclerophylla were significantly higher in summer than in the other seasons, while Pn of L. glaber and C. glauca was significantly higher in autumn than in the other seasons. In the forest gap and edge habitats, the annual mean values of the maximum net photosynthetic rate (Amax), the light saturation point (LSP), light compensation point (LCP) and dark respiration rate (Rd) of P. massoniana were the highest, followed by C. sclerophylla, and those of L. glaber and C. glauca were the lowest. In the understory habitat, the annual mean values of Amax and the apparent quantum yield (AQY) of C. glauca were the highest, followed by L. glaber and C. sclerophylla, and those of P. massoniana were the lowest. The annual mean values of the maximum rate of carboxylation (Vc max), maximum rate of electron transport (Jmax) and triose phosphate use rate (TPU) of P. massoniana were significantly higher than those of the other three plant species in the three different light regimes. During the four seasons, the photochemical maximum efficiency of PSII (Fv/Fm) of P. massoniana and C. sclerophylla in the forest gap habitat was significantly higher, while those of L. glaber and C. glauca in the understory habitat were significantly higher than in the other light regimes. The maximum values of Fv/Fm of P. massoniana and C. sclerophylla were the highest in summer, and those of L. glaber and C. glauca were the highest in autumn. It suggested that P. massoniana and C. sclerophylla were more suitable for habitats with high light intensities such as forest gaps, and L. glaber and C. glauca were more suitable for habitats with low light intensities such as the understory. During ecological succession, P. massoniana and C. sclerophylla would withdraw from the community with the increasing canopy density, and L. glaber and C. glauca would be the dominant species in the climax community.
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An AIE-active boron-difluoride complex: multi-stimuli-responsive fluorescence and application in data security protection.
Chem. Commun. (Camb.)
PUBLISHED: 09-16-2014
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A novel AIE-active boron-difluoride complex (PTZ) was synthesized which exhibits multi-stimuli responsive characteristics. Its colours and emissions can be switched by mechanical grinding, organic solvent vapours and acid/base vapours. This complex can be utilized in data encryption and decryption based on the protonation-deprotonation effect.
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[Low frequency-based non-uniform sampling strategy to improve Chinese recognition in cochlear implant].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 09-16-2014
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To enhance speech recognition, as well as Mandarin tone recognition in noice, we proposed a speech coding strategy called zero-crossing of fine structure in low frequency (LFFS) for cochlear implant based on low frequency non-uniform sampling (LFFS for short). In the range of frequency perceived boundary of human ear, we used zero-crossing time of the fine structure to generate the stimulus pulse sequences based on the frequency selection rule. Acoustic simulation results showed that although on quiet background the performance of LFFS was similar to continuous interleaved sampling (CIS), on the noise background the performance of LFFS in Chinese tones, words and sentences were significantly better than CIS. In addition to this, we also got better Mandarin recognition factors distribution by using the improved index distribution model. LFFS contains more tonal information which was able to effectively improve Mandarin recognition of the cochlear implant.
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Proximal femoral nail vs. dynamic hip screw in treatment of intertrochanteric fractures: a meta-analysis.
Med. Sci. Monit.
PUBLISHED: 09-13-2014
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The aim of this meta-analysis was to compare the outcomes of proximal femoral nail (PFN) and dynamic hip screw (DHS) in treatment of intertrochanteric fractures.
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Optimization of Process Parameters of Extraction of Amentoflavone, Quercetin and Ginkgetin from Taxus chinensis Using Supercritical CO2 Plus Co-Solvent.
Molecules
PUBLISHED: 09-10-2014
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The effects of extraction time, temperature, pressure and different concentration of ethanol and their interactions on the yields of amentoflavone, quercetin and ginkgetin extracted from Taxus chinensis by supercritical CO2 were investigated by using a central composite design (CCD). An CCD experimental design with four factors and five levels was used to optimize the extraction parameters. Ultra performance liquid chromatography (UPLC) was used to analyze the content of the tree components in the extracts. Experimental results show that the main effects of factors and their interactions are significant on the yields (p < 0.05). The optimal extraction conditions were established for the three compounds: yield of 4.47 mg/g for amentoflavone at 48 °C, 25 MPa, 2.02 h and 78.5% ethanol, 3.73 mg/g for quercetin at 46 °C, 24 MPa, 2.3 h, 82% ethanol and 3.47 mg/g for ginkgetin at 48 °C, 20 MPa, 2.38 h, 82% ethanol, respectively.
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A dedicated high-resolution PET imager for plant sciences.
Phys Med Biol
PUBLISHED: 09-05-2014
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PET provides an in vivo molecular and functional imaging capability that could be valuable for studying the interaction of plants in changing environments at the whole-plant level. We have developed a dedicated plant PET imager housed in a plant growth chamber (PGC), which provides a fully controlled environment. The system currently contains two types of scintillation detector modules from commercial small animal PET scanners: 84 microPET® detectors, which are made with scintillation crystal arrays of 2.2 mm(3) × 2.2 mm(3) × 10 mm(3) crystals to provide a large detection area; and 32 Inveon™ detectors, which are made with scintillation crystal arrays of 1.5 mm(3) × 1.5 mm(3) × 10 mm(3) crystals to provide higher spatial resolution. The detector modules are configured to form two half-rings, which provide a 15 cm-diameter trans-axial field of view (FOV) for dynamic tomographic imaging of small plants. Alternatively, the Inveon detectors can be reconfigured to form quarter-rings, which provide a 25 cm FOV using step-and-shoot motion. The imager contains two linear stages that move detectors vertically at different heights for multisection scanning, and two rotation stages to collect coincidence events from all angles when using the step-and-shoot acquisition. The detector modules and mechanical components of the imager are housed inside a PGC that regulates the environmental parameters. The system has a typical energy resolution of 15% for the Inveon detectors and 24% for the microPET detectors, timing resolution of 1.8 ns, and sensitivity of 1.3%, 1.4% and 3.0% measured at the center of the FOV, 5 cm off to the larger half-ring and 5 cm off to the smaller half-ring, respectively (with a 350-650 keV energy window and 3.1 ns timing window). The system's spatial resolution is capable of resolving rod sources of 1.25 mm diameter spaced 2.5 mm apart (center to center) using the ML-EM reconstruction algorithm. Preliminary imaging experiments using soybean and wild type and mutant maize labeled with (11)CO2 produced high-quality dynamic PET images that reveal the translocation and distribution patterns of photoassimilates. This system can be used to provide an in vivo molecular and functional imaging capability for plant research.
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[Study on artificial compound feed for Buthus martensii].
Zhong Yao Cai
PUBLISHED: 09-02-2014
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To solve the problem that the single feed causing malnutrition, extension of the life cycle and low survival rates of Buthus martensii.
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New insight into the hydrocarbon-pool chemistry of the methanol-to-olefins conversion over zeolite H-ZSM-5 from GC-MS, solid-state NMR spectroscopy, and DFT calculations.
Chemistry
PUBLISHED: 09-01-2014
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Over zeolite H-ZSM-5, the aromatics-based hydrocarbon-pool mechanism of methanol-to-olefins (MTO) reaction was studied by GC-MS, solid-state NMR spectroscopy, and theoretical calculations. Isotopic-labeling experimental results demonstrated that polymethylbenzenes (MBs) are intimately correlated with the formation of olefin products in the initial stage. More importantly, three types of cyclopentenyl cations (1,3-dimethylcyclopentenyl, 1,2,3-trimethylcyclopentenyl, and 1,3,4-trimethylcyclopentenyl cations) and a pentamethylbenzenium ion were for the first time identified by solid-state NMR spectroscopy and DFT calculations under both co-feeding ([(13) C6 ]benzene and methanol) conditions and typical MTO working (feeding [(13) C]methanol alone) conditions. The comparable reactivity of the MBs (from xylene to tetramethylbenzene) and the carbocations (trimethylcyclopentenyl and pentamethylbenzium ions) in the MTO reaction was revealed by (13) C-labeling experiments, evidencing that they work together through a paring mechanism to produce propene. The paring route in a full aromatics-based catalytic cycle was also supported by theoretical DFT calculations.
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The results of a two-stage double switch operation for congenital corrected transposition of the great arteries with a deconditioned morphologically left ventricle.
Interact Cardiovasc Thorac Surg
PUBLISHED: 08-30-2014
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The purpose of this retrospective study was to evaluate a two-stage double switch operation, morphological left ventricular (mLV) retraining followed by an atrial-arterial switch operation, in the management of patients with congenitally corrected transposition of the great arteries (CCTGA) and a deconditioned mLV.
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Downregulation of microRNA-100 correlates with tumor progression and poor prognosis in colorectal cancer.
Med. Oncol.
PUBLISHED: 08-28-2014
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Dysregulation of microRNA-100 (miR-100) has been shown to be involved in cancer tumorigenesis and progression of several cancer types. However, its expression patterns in tumors are controversial. The aim of this study was to investigate the expression and clinical significance of miR-100 in colorectal cancer (CRC). Quantitative real-time PCR was used to analyze the expression of miR-100 in 138 pairs of human CRC and adjacent normal tissues. The prognostic values of miR-100 in CRC were also analyzed. The results showed that the miR-100 expression was significantly downregulated in CRC tissues when compared to adjacent normal tissues (P<0.001). Also, low miR-100 expression was observed to be significantly correlated with larger tumor size (P=0.023), higher incidence of lymph node metastasis (P=0.009), and advanced TNM stage (P=0.016). More importantly, Kaplan-Meier analysis showed that CRC patients with low miR-100 expression tended to have shorter overall survival. In multivariate analysis stratified for known prognostic variables, low miR-100 expression was identified as an independent prognostic factor for overall survival. In conclusion, our data indicated for the first time that the downregulation of miR-100 was associated with advanced clinical features and poor prognosis of CRC patients, suggesting that miR-100 downregulation may serve as an unfavorable prognostic biomarker in CRC.
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Core-Shell ?-Fe2 O3 @?-MoO3 Nanorods as Lithium-Ion Battery Anodes with Extremely High Capacity and Cyclability.
Chem Asian J
PUBLISHED: 08-28-2014
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?-Fe2 O3 nanoparticles are uniformly coated on the surface of ?-MoO3 nanorods through a two-step hydrothermal synthesis method. As the anode of a lithium-ion battery, ?-Fe2 O3 @?-MoO3 core-shell nanorods exhibit extremely high lithium-storage performance. At a rate of 0.1?C (10?h per half cycle), the reversible capacity of ?-Fe2 O3 @?-MoO3 core-shell nanorods is 1481?mA?h?g(-1) and a value of 1281?mA?h?g(-1) is retained after 50?cycles, which is much higher than that retained by bare ?-MoO3 and ?-Fe2 O3 and higher than traditional theoretical results. Such a good performance can be attributed to the synergistic effect between ?-Fe2 O3 and ?-MoO3 , the small size effect, one-dimensional nanostructures, short paths for lithium diffusion, and interface spaces. Our results reveal that core-shell nanocomposites have potential applications as high-performance lithium-ion batteries.
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Metastatic consequences of immune escape from NK cell cytotoxicity by human breast cancer stem cells.
Cancer Res.
PUBLISHED: 08-27-2014
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Breast cancer stem-like cells (BCSC) are crucial for metastasis but the underlying mechanisms remain elusive. Here, we report that tumor-infiltrating natural killer (NK) cells failed to limit metastasis and were not associated with improved therapeutic outcome of BCSC-rich breast cancer. Primary BCSCs were resistant to cytotoxicity mediated by autologous/allogeneic NK cells due to reduced expression of MICA and MICB, two ligands for the stimulatory NK cell receptor NKG2D. Furthermore, the downregulation of MICA/MICB in BCSCs was mediated by aberrantly expressed oncogenic miR20a, which promoted the resistance of BCSC to NK cell cytotoxicity and resultant lung metastasis. The breast cancer cell differentiation-inducing agent, all-trans retinoic acid, restored the miR20a-MICA/MICB axis and sensitized BCSC to NK cell-mediated killing, thereby reducing immune escape-associated BCSC metastasis. Together, our findings reveal a novel mechanism for immune escape of human BCSC and identify the miR20a-MICA/MICB signaling axis as a therapeutic target to limit metastatic breast cancer. Cancer Res; 74(20); 5746-57. ©2014 AACR.
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Oxidation of bromophenols and formation of brominated polymeric products of concern during water treatment with potassium permanganate.
Environ. Sci. Technol.
PUBLISHED: 08-26-2014
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The extensive use of bromophenols (BrPs) in industrial products leads to their occurrence in freshwater environments. This study explored the oxidation kinetics of several BrPs (i.e., 2-BrP, 3-BrP, 4-BrP, 2,4-diBrP, and 2,6-diBrP) and potential formation of brominated polymeric products of concern during water treatment with potassium permanganate [Mn(VII)]. These BrPs exhibited appreciable reactivity toward Mn(VII) with the maxima of second-order rate constants (kMn(VII)) at pH near their pKa values, producing bell-shaped pH-rate profiles. The unusual pH-dependency of kMn(VII) was reasonably explained by a tentative reaction model, where the formation of an intermediate between Mn(VII) and dissociated BrP was likely involved. A novel and powerful precursor ion scan (PIS) approach was used for selective detection of brominated oxidation products by liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry. Results showed that brominated dimeric products such as hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and hydroxylated polybrominated biphenyls (OH-PBBs) were readily produced. For instance, 2'-OH-BDE-68, one of the most naturally abundant OH-PBDEs, could be formed at a relatively high yield possibly via the coupling between bromophenoxyl radicals generated from the one-electron oxidation of 2,4-diBrP by Mn(VII). Given the altered or enhanced toxicological effects of these brominated polymeric products compared to the BrP precursors, it is important to better understand their reactivity and fate before Mn(VII) is applied by water utilities for the oxidative treatment of BrP-containing waters.
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Role of the Akt/GSK-3?/CRMP-2 pathway in axon degeneration of dopaminergic neurons resulting from MPP+ toxicity.
Brain Res.
PUBLISHED: 08-21-2014
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Parkinson?s disease (PD) is the most common neurodegenerative disease of the basal ganglia. Earlier reports suggest that the main pathological change in PD is due to apoptosis of dopaminergic neuronal soma in the substantia nigra (SN). The therapies for PD are also largely focused on the prevention of degeneration of the neuronal soma. However, these treatments can only provide temporary relief by delaying the progression of the disease and are therefore unable to prevent the long term neurodegeneration process. This limitation of the existing therapeutic treatment indicates that there may be other causes that either occur earlier or are independent of apoptosis of neuronal soma. Previous studies have shown that axon degeneration may play an important role in PD, and that this may occur at an early stage of the disease. Thus, preventing axon degeneration may be a potential new approach for therapeutic treatment for PD and future therapies can be useful if emphasis is given on the mechanisms of axon degeneration. It has been recognized that microtubule disassembly leads to axon degeneration because the depolymerized microtubules are more likely to be degraded. Previous studies have shown that glycogen synthase kinase-3? (GSK-3?)/collapsin response mediator protein 2 (CRMP-2) signaling pathway could be regulated by Akt for axonal-dendritic polarity. CRMP-2 is critical for specifying axon/dendrite fate possibly by promoting neurite elongation via microtubule assembly. However, whether Akt could regulate GSK-3?/CRMP-2 pathway and the possible effects of this regulation is unclear in dopaminergic axon degeneration induced by 1-methyl-4-phenylpyridiniumion (MPP+). In this study, we observe the degeneration of axon and neuronal soma by scanning electron microscope and tyrosine hydroxylase staining (TH) using a PD model in dopaminergic neurons in vitro. In addition to this, we detect the expression of total and phosphorylated form of Akt, GSK-3? and CRMP-2, as well as the axonal injury marker amyloid precursor protein (APP). From our studies, we observe that axon degeneration is a characteristic feature in the cascade of events that follow when neurons are induced by MPP+. This degeneration process occurs earlier in case of PD and is more severe than the degeneration of the neuronal soma and Akt/ GSK-3?/CRMP-2 pathway is involved in this process.
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Phytotoxicity of 4,8-dihydroxy-1-tetralone isolated from Carya cathayensis Sarg. to various plant species.
Molecules
PUBLISHED: 08-19-2014
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The aqueous extract from Carya cathayensis Sarg. exocarp was centrifuged, filtered, and separated into 11 elution fractions by X-5 macroporous resin chromatography. A phenolic compound, 4,8-dihydroxy-1-tetralone (4,8-DHT) was isolated from the fractions with the strongest phytotoxicity by bioassy-guided fractionation, and investigated for phytotoxicity on lettuce (Latuca sativa L.), radish (Raphanus sativus L.), cucumber (Cucumis sativus L.), onion (Allium cepa L.) and wheat (Triticum aestivum L.). The testing results showed that the treatment with 0.6 mM 4,8-DHT could significantly depress the germination vigor of lettuce and wheat, reduce the germination rate of lettuce and cucumber, and also inhibit radicle length, plumule length, and fresh weight of seedlings of lettuce and onion, but could significantly promote plumule length and fresh weight of seedlings of cucumber (p < 0.05). For the tested five plants, the 4,8-DHT was the most active to the seed germination and seedling growth of lettuce, indicating that the phytotoxicity of 4,8-DHT had the selectivity of dosage, action target (plant type) and content (seed germination or seedling growth).
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Evaluation of an oil-producing green alga Chlorella sp. C2 for biological DeNOx of industrial flue gases.
Environ. Sci. Technol.
PUBLISHED: 08-19-2014
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NOx, a significant portion of fossil fuel flue gases, are among the most serious environmental issues in the world and must be removed in an additional costly gas treatment step. This study evaluated the growth of the green alga Chlorella sp. C2 under a nitrite-simulated NOx environment and the removal rates of actual flue gas fixed salts (FGFSs) from Sinopec's Shijiazhuang refinery along with lipid production. The results showed that nitrite levels lower than 176.5 mM had no significant adverse effects on the cell growth and photosynthesis of Chlorella sp. C2, demonstrating that this green alga could utilize nitrite and NOx as a nitrogen source. High concentrations of nitrite (88.25-176.5 mM) also resulted in the accumulation of neutral lipids. A 60% nitrite removal efficiency was obtained together with the production of 33% algae lipids when cultured with FGFS. Notably, the presence of nitrate in the FGFS medium significantly enhanced the nitrite removal capability, biomass and lipid production. Thus, this study may provide a new insight into the economically viable application of microalgae in the synergistic combination of biological DeNOx of industrial flue gases and biodiesel production.
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Identification of 9 serum microRNAs as potential noninvasive biomarkers of human astrocytoma.
Neuro-oncology
PUBLISHED: 08-18-2014
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Circulating microRNAs (miRNAs) are emerging as promising biomarkers for human cancer. In the current study, we investigated the potential use of serum miRNAs as biomarkers for diagnosis and prognosis in a cohort of Chinese astrocytoma patients.
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Comparative study on PCDD/F pollution in soil from the Antarctic, Arctic and Tibetan Plateau.
Sci. Total Environ.
PUBLISHED: 08-17-2014
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The concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in 35 soil samples collected from Fildes Peninsula in the Antarctic, Ny-Ålesund in the Arctic, and Zhangmu-Nyalam in the Tibetan Plateau were reported in this study. A comparison of the total concentration and TEQ of PCDD/Fs at the Three Poles was conducted. Both the total concentration and TEQ of PCDD/Fs demonstrates a decreasing trend in the order of Zhangmu-Nyalam (mean: 26.22 pg/g, 0.37 pg I-TEQ/g)>Ny-Ålesund (mean: 9.97 pg/g, 0.33 pg I-TEQ/g)>Fildes Peninsula (mean: 2.18 pg/g, 0.015 pg I-TEQ/g) (p<0.05). In all samples, the congener and homologue profiles dominated with higher (seven and eight) chlorinated PCDD/Fs (more than 85% of the total mass percentage of PCDD/Fs) at the Three Poles. Finally, a FLEXPART backward simulation was used to preliminarily identify the potential local and regional anthropogenic sources of PCDD/Fs. The results imply that the air masses passing over surrounding regions with significant PCDD/F emissions might contribute to the occurrence of PCDD/Fs in both the Arctic and Tibetan Plateau.
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Alkylation of benzene with carbon monoxide over Zn/H-ZSM-5 zeolite studied using in situ solid-state NMR spectroscopy.
Chem. Commun. (Camb.)
PUBLISHED: 08-16-2014
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Using in situ solid-state NMR spectroscopy we show that CO can act as an alkylating reagent and react with benzene to produce toluene over a Zn/H-ZSM-5 zeolite. In the alkylation reaction, CO provides the methyl group of toluene via a methoxy intermediate.
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Gender Differences in Current Received during Transcranial Electrical Stimulation.
Front Psychiatry
PUBLISHED: 08-15-2014
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Low current transcranial electrical stimulation (tCS) is an effective but somewhat inconsistent tool for augmenting neuromodulation. In this study, we used 3D MRI guided electrical transcranial stimulation modeling to estimate the range of current intensities received at cortical brain tissues. Combined T1, T2, and proton density MRIs from 24 adult subjects (12 male and 12 female) were modeled with virtual electrodes placed at F3, F4, C3, and C4. Two sizes of electrodes 20?mm round and 50?mm?×?45?mm were examined at 0.5, 1, and 2?mA input currents. The intensity of current received was sampled in a 1-cm sphere placed at the cortex directly under each scalp electrode. There was a 10-fold difference in the amount of current received by individuals. A large gender difference was observed with female subjects receiving significantly less current at targeted parietal cortex than male subjects when stimulated at identical current levels (P?
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MiR-143 inhibits EGFR-signaling-dependent osteosarcoma invasion.
Tumour Biol.
PUBLISHED: 08-14-2014
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The molecular regulation of the invasion of osteosarcoma (OS) remains elusive. Here, we reported significant lower level of miR-143 and significant levels of phosphorylated EGFR and MMP9 in the resected OS from the patients, compared to the adjacent normal tissue. Moreover, strong correlation was detected among these three factors. We thus hypothesized existence of a causal link, which prompted us to use two human OS cell lines to study the interaction of miR-143, MMP9, and activation of EGFR signaling. We found that EGF-induced EGFR phosphorylation in both lines activated MMP9, and consequently cancer invasiveness. Both an inhibitor for EGFR phosphorylation and an inhibitor for ERK1/2 phosphorylation significantly inhibited the EGF-induced activation of MMP9. Moreover, miR-143 levels did not alter by EGF-induced EGFR phosphorylation, while overexpression of miR-143 antagonized EGF-induced MMP9 activation without affecting EGFR phosphorylation. Taken together, our data suggest that miR-143 inhibits EGFR signaling through its downstream ERK/MAPK signaling cascades to control MMP9 expression in OS. Thus, miR-143, EGFR, and MMP9 are therapeutic targets for inhibiting OS invasion.
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Oxygen reduction reaction in a droplet on graphite: direct evidence that the edge is more active than the basal plane.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 08-14-2014
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Carbon-based metal-free electrocatalysts for the oxygen reduction reaction (ORR) in alkaline medium have been extensively investigated with the aim of replacing the commercially available, but precious platinum-based catalysts. For the proper design of carbon-based metal-free electrocatalysts for the ORR, it would be interesting to identify the active sites of the electrocatalyst. The ORR was now studied with an air-saturated electrolyte solution droplet (diameter ca. 15??m), which was deposited at a specified position either on the edge or on the basal plane of highly oriented pyrolytic graphite. Electrochemical measurements suggest that the edge carbon atoms are more active than the basal-plane ones for the ORR. This provides a direct way to identify the active sites of carbon materials for the ORR. Ball-milled graphite and carbon nanotubes with more exposed edges were also prepared and showed significantly enhanced ORR activity. DFT calculations elucidated the mechanism by which the charged edge carbon atoms result in the higher ORR activity.
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Theoretical investigation on carbon nucleation on nickel carbides at initial stages of single-walled carbon nanotube formation.
Phys Chem Chem Phys
PUBLISHED: 08-12-2014
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It is a long-standing controversy whether metal carbide clusters do exist during the nucleation and growth process of single-walled carbon nanotubes (SWCNTs). In the current work, we are trying to elucidate the carbon nucleation on nickel carbides during the initial stages based on density functional theory calculated formation energy and chemical potential for a series of Ni55Cn carbides (n is the number of carbon atoms dissolved in the Ni55 cluster). It is found that the formation energies of the Ni55Cn carbides decrease gradually with an increase of dissolved carbon atomic numbers, meaning the Ni55Cn carbides are thermodynamically stable. Meanwhile, the calculated chemical potentials indicate that not only nickel carbides are preferentially formed during the initial stage of the SWCNT nucleation, but also saturated nickel carbides may be able to exist during the nucleation and growth process of SWCNTs. In addition, the nickel carbides have a high selectivity for the formation of the carbon pentagon and carbon structures with pentagon-incorporated end-edge according to the adsorption energies. All of these findings provide opportunities in controlling the growth of the SWCNTs.
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Intermittent cold stress enhances features of atherosclerotic plaque instability in apolipoprotein E?deficient mice.
Mol Med Rep
PUBLISHED: 08-07-2014
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The cold weather is associated with an increased occurrence of acute coronary events. However, the mechanisms underlying cold?induced myocardial infarctions have not yet been fully elucidated. In the present study, 20 male, eight week?old, apolipoprotein E (ApoE)?deficient mice were subjected to either control conditions or intermittent cold exposure for eight weeks. Mice in the cold group were placed in a cold room at 4?C for 4 h per day, while the mice in the control group were kept in a room at 24?C. Cold?exposed mice did not significantly differ from control mice in body weight, fasting glucose concentration and plasma lipid levels, including triglyceride, total cholesterol, low?density lipoprotein and high?density lipoprotein. The hematoxylin and eosin?stained sections of the aortic root demonstrated increased plaque size in the cold group compared with the control group (P<0.01). Furthermore, cold?treated mice exhibited significantly decreased plaque collagen and vascular smooth muscle cell deposition and increased macrophage and lymphocyte content (P<0.05 or P<0.01), which are typical features of atherosclerotic plaque instability. Additionally, the protein expression of matrix metalloproteinase (MMP)?2, MMP?9 and MMP?14 were significantly increased (P<0.05 or P<0.01), whereas tissue inhibitor of matrix metalloproteinase (TIMP)?1 expression was decreased (P<0.05) following exposure to a cold environment. The present study demonstrated that chronic intermittent cold stress may increase atherosclerotic plaque size and promote plaque instability in ApoE?deficient mice by altering the balance of MMPs and TIMPs. These findings may provide mechanistic insights into sudden cardiac death in cold environments.
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A genomic survey of thirty soybean-infecting bean common mosaic virus (BCMV) isolates from China pointed BCMV as a potential threat to soybean production.
Virus Res.
PUBLISHED: 08-05-2014
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Widely known as a severe pathogen of bean plants, the bean common mosaic virus (BCMV) has been reported to infect soybeans only sporadically and the involved strains were all found in China regions. To explore variations among soybean-infecting BCMV strains, hundreds of soybean mosaic leave samples were collected throughout China, with a total of 30 BCMV isolates detected and their genomes sequenced. These newly obtained genomes, together with 16 other BCMV genomes available in GenBank were examined from multiple aspects to characterize BCMV evolutionary processes. Phylogenetic analysis showed that both soybean-infecting BCMVs (group I) and peanut-infecting BCMVs (group II) are distantly related to other BCMVs, suggesting ancestral differentiation and host adaptation. Genetic variation analysis showed that P1, P3 and 6K2 genes and the beginning portion of CP gene showed higher levels of variation relative to other genes. Moreover, selection analyses further confirmed that a number of sites within the P1 and P3 genes have suffered positive selection. These obtained BCMV sequences also exhibit high recombination frequencies, indicating a more dynamic evolutionary history. Finally, 12 different soybean cultivars were challenged with two BCMV isolates (DXH015 and HZZB011), with most of the cultivars successfully infected. These findings suggest that BCMV is indeed a potential threat to soybean production.
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Interactions of CaMKII with dopamine D2 receptors: roles in levodopa-induced dyskinesia in 6-hydroxydopamine lesioned Parkinson's rats.
Sci Rep
PUBLISHED: 07-31-2014
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Ca(2+)/calmodulin-dependent protein kinase II is a synapse-enriched kinase in mammalian brains. This kinase interacts with various synaptic proteins to regulate expression and function of interacting proteins and thereby modulates synaptic transmission. CaMKII and its interacting partners are also believed to play a pivotal role in the pathogenesis of various neurological and neurodegenerative disorders, such as Parkinson's disease (PD). In this study, we found that CaMKII? binds to dopamine D2 receptors (D2R) in vitro. A distal region in the D2R third intracellular loop harbors CaMKII? binding. Endogenous CaMKII? was also found to interact with native D2Rs in rat striatal neurons in which D2Rs are expressed at a high level. In addition, in a rat 6-hydroxydopamine lesioned model of PD, chronic levodopa administration induced characteristic dyskinesia. In parallel, levodopa induced an increase in CaMKII?-D2R interactions in striatal neurons. Intrastriatal injection of a Tat-fusion and CaMKII?-D2R interaction-dead peptide (Tat-D2Ri) reversed this increase in the interaction between two proteins. Tat-D2Ri also alleviated dyskinetic behaviors induced by levodopa. These results reveal a new interaction between CaMKII? and D2Rs in striatal neurons which is sensitive to long-term administration of levodopa in PD rats. Prevention of the response of CaMKII?-D2R interactions to levodopa can alleviate levodopa-induced dyskinesia.
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Novel Na2Mo4O13/?-MoO3 hybrid material as highly efficient CWAO catalyst for dye degradation at ambient conditions.
Sci Rep
PUBLISHED: 07-25-2014
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We report a novel hybrid material Na2Mo4O13/?-MoO3 as highly efficient catalytic wet air oxidation (CWAO) catalyst, which showed the highest ever activity at room temperature and atmosphere pressure for the degradation of cationic red GTL. SEM and TEM analyses indicated that this hybrid catalyst has bamboo-shaped nanofiber morphology. In view of practical applications, the influence of some key parameters including operation temperature, catalyst calcination temperature, and the volume of dye wastewater have been optimized. The mechanism for the superior catalytic performance was investigated. XRD, XPS, and ESR suggested the Na2Mo4O13/?-MoO3 hybrid catalyst possesses more O(2-) ions in the oxygen deficient regions than neat ?-MoO3, promoting the formation of active ·OH radicals and resulting in a higher activity. Considering the facile preparation and its superior activity, this novel catalyst is promising for practical dye wastewater treatment.
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Treatment with CA-074Me, a Cathepsin B inhibitor, reduces lung interstitial inflammation and fibrosis in a rat model of polymyositis.
Lab. Invest.
PUBLISHED: 07-19-2014
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Cathepsin B (CB) is involved in the turnover of proteins and has various roles in maintaining the normal metabolism of cells. In our recent study, CB is increased in the muscles of polymyositis/dermatomyositis (PM/DM). However, the role of CB in interstitial lung disease (ILD) has not been reported. ILD is a frequent complication of PM/DM, which is the leading cause of death in PM/DM. It carries high morbidity and mortality in connective tissue diseases, characterized by an overproduction of inflammatory cytokines and induced fibrosis, resulting in respiratory failure. The etiology and pathogenesis of ILD remain incompletely understood. This study investigated whether treatment with CA-074Me, a specific inhibitor of CB, attenuates ILD in PM. CB expression, inflammation, and fibrosis were analyzed in the lung tissues from patients with PM/DM. The animal model of PM was induced in guinea pigs with Coxsackie virus B1 (CVB1). CA-074Me was given 24?h after CVB1 injection for 7 consecutive days. At the end of the experiment, the animals were killed and lung tissues were collected for the following analysis. Inflammation, fibrosis and apoptosis cells, and cytokines were assessed by histological examinations and immunohistochemical analyses, western blot analysis and transferase-mediated dUTP nick-end labeling assay. In patients with PM/DM, the protein levels of CB were significantly elevated in lung tissues compared with healthy controls, which correlated with increases in inflammation and fibrosis. Similarly, the expression of CB, inflammation and fibrosis, CD8(+) T cell, CD68(+) cell, tumor necrosis factor-alpha, transforming growth factor-beta1 infiltrations, and apoptotic cell death were significantly increased in lung tissues of the guinea-pig model of CVB1-induced PM. These changes were attenuated by the administration of CA-074Me. In conclusion, this study demonstrates that PM/DM increases CB expression in lung tissues and inhibition of CB reduces ILD in a guinea-pig model of CVB1-induced PM. This finding suggests that CB may be a potential therapeutic target for ILD.Laboratory Investigation advance online publication, 10 November 2014; doi:10.1038/labinvest.2014.135.
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Anandamide protects HT22 cells exposed to hydrogen peroxide by inhibiting CB1 receptor-mediated type 2 NADPH oxidase.
Oxid Med Cell Longev
PUBLISHED: 07-17-2014
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Endogenous cannabinoid anandamide (AEA) protects neurons from oxidative injury in rodent models; however the mechanism of AEA-induced neuroprotection remains to be determined. Activation of neuronal NADPH oxidase 2 (Nox2) contributes to oxidative damage of the brain, and inhibition of Nox2 can attenuate cerebral oxidative stress. We aimed to determine whether the neuronal Nox2 was involved in protection mediated by AEA.
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Dendrobium candidum Wall. ex Lindl. attenuates CCl4-induced hepatic damage in imprinting control region mice.
Exp Ther Med
PUBLISHED: 07-08-2014
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The aim of the present study was to determine the preventive effect of the traditional Chinese medicine, Dendrobium candidum Wall ex Lindl. (D. candidum), on CCl4-induced hepatic damage in mice. The CCl4-induced hepatic damage mice were treated with D. candidum, and the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), triglyceride (TG) and total cholesterol (TC) were determined. In addition, serum cytokine levels of interleukin (IL)-6, IL-12, tumor necrosis factor (TNF)-? and interferon (IFN)-? were analyzed with kits, while liver tissues were analyzed using hematoxylin and eosin staining and reverse transcription polymerase chain reaction (RT-PCR). Furthermore, the contents of D. candidum were determined by nuclear magnetic resonance (NMR). D. candidum was demonstrated to successfully prevent hepatic damage in mice. The serum levels of AST, ALT and LDH were significantly decreased when the mice were treated with 200 and 400 mg/kg D. candidum, as compared with the control mice (P<0.05). The lowest enzymatic activities were exhibited in the 400 mg/kg D. candidum group, which produced similar results to the positive control drug, silymarin. In addition, in the 400 mg/kg D. candidum group, the highest levels of TG and TC were observed among the treated groups. D. candidum-treated groups also demonstrated reduced levels of the serum proinflammatory cytokines, IL-6, IL-12, TNF-? and IFN-?. The sections of liver tissue examined during histopathology in the high concentration 400 mg/kg D. candidum group recovered well from CCl4 damage; however, the sections in the 200 mg/kg D. candidum group revealed necrosis to a more serious degree. RT-PCR analysis was conducted on inflammation-associated genes, including nuclear factor (NF)-?B, I?B-?, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, in the livers of the mice. The 400 mg/kg D. candidum group demonstrated significantly decreased mRNA expression levels of NF-?B, iNOS and COX-2, but an increased expression level of I?B-? when compared with the CCl4-treated control group. Furthermore, using NMR, 11 compounds were identified in the D. candidum leaf, whose functional contents may aid the preventive effect observed in the current study. Therefore, D. candidum may potentially contribute to the prevention of CCl4-induced hepatic damage in vivo.
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Effect of Inoculation Process on Lycopene Production by Blakeslea trispora in a Stirred-Tank Reactor.
Appl. Biochem. Biotechnol.
PUBLISHED: 07-01-2014
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Lycopene biosynthesis by Blakeslea trispora was greatly enhanced in a stirred-tank reactor when a nonsynchronous inoculation process, in which the (+) mating type was inoculated after the (-) mating type has been grown for a certain period of time, was applied. The lycopene concentration with nonsynchronous inoculation in a 24-h inoculation interval was 33 % higher than that with synchronous inoculation. The optimum inoculation ratio was 1:2 (+/-) at the 36 and 48 h inoculum age of mating types (+) and (-), respectively. Fermentation time for the individual strains and mated conditions showed that the (+) mating type grows faster than the (-) mating type. Morphological observation showed that the mycelium ratio of B. trispora (-) in mating culture with nonsynchronous inoculation was higher than that with synchronous inoculation. The results indicated that nonsynchronous inoculation process increased the dominance of B. trispora (-) in joint cultivation and hence stimulated lycopene biosynthesis.
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Acetone, butanol, and ethanol production from gelatinized cassava flour by a new isolates with high butanol tolerance.
Bioresour. Technol.
PUBLISHED: 07-01-2014
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To obtain native strains resistant to butanol toxicity, a new isolating method and serial enrichment was used in this study. With this effort, mutant strain SE36 was obtained, which could withstand 35g/L (compared to 20g/L of the wild-type strain) butanol challenge. Based on 16s rDNA comparison, the mutant strain was identified as Clostridium acetobutylicum. Under the optimized condition, the phase shift was smoothly triggered and fermentation performances were consequently enhanced. The maximum total solvent and butanol concentration were 23.6% and 24.3%, respectively higher than that of the wild-type strain. Furthermore, the correlation between butanol produced and the butanol tolerance was investigated, suggesting that enhancing butanol tolerance could improve butanol production. These results indicate that the simple but effective isolation method and acclimatization process are a promising technique for isolation and improvement of butanol tolerance and production.
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Metabolic control of oocyte development: linking maternal nutrition and reproductive outcomes.
Cell. Mol. Life Sci.
PUBLISHED: 06-22-2014
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Obesity, diabetes, and related metabolic disorders are major health issues worldwide. As the epidemic of metabolic disorders continues, the associated medical co-morbidities, including the detrimental impact on reproduction, increase as well. Emerging evidence suggests that the effects of maternal nutrition on reproductive outcomes are likely to be mediated, at least in part, by oocyte metabolism. Well-balanced and timed energy metabolism is critical for optimal development of oocytes. To date, much of our understanding of oocyte metabolism comes from the effects of extrinsic nutrients on oocyte maturation. In contrast, intrinsic regulation of oocyte development by metabolic enzymes, intracellular mediators, and transport systems is less characterized. Specifically, decreased acid transport proteins levels, increased glucose/lipid content and elevated reactive oxygen species in oocytes have been implicated in meiotic defects, organelle dysfunction and epigenetic alteration. Therefore, metabolic disturbances in oocytes may contribute to the diminished reproductive potential experienced by women with metabolic disorders. In-depth research is needed to further explore the underlying mechanisms. This review also discusses several approaches for metabolic analysis. Metabolomic profiling of oocytes, the surrounding granulosa cells, and follicular fluid will uncover the metabolic networks regulating oocyte development, potentially leading to the identification of oocyte quality markers and prevention of reproductive disease and poor outcomes in offspring.
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Optimal intervention time of vagal stimulation attenuating myocardial ischemia/reperfusion injury in rats.
Inflamm. Res.
PUBLISHED: 05-27-2014
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To determine the optimal intervention time of the vagal stimulation (VS) attenuating myocardial ischemia/reperfusion injury (IRI).
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Computer-assisted design and synthesis of molecularly imprinted polymers for the simultaneous determination of six carbamate pesticides from environmental water.
J Sep Sci
PUBLISHED: 05-23-2014
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The computer-assisted design and synthesis of molecularly imprinted polymers for the simultaneous capture of six carbamate pesticides from environmental water are reported in this work. The quantum mechanical computational approach was employed to design the molecularly imprinted polymers with carbofuran as template. The interaction energies between the template molecule and different functional monomers in various solvents were calculated to assist in the selection of the functional monomer and porogen. The optimised molecularly imprinted polymer was subsequently used as a class-selective sorbent in solid-phase extraction for pre-concentration and determination of carbamates from environmental water. The parameters influencing the extraction efficiency of the molecularly imprinted solid-phase extraction procedure were systematically investigated to facilitate the class-selective extraction. For the proposed method, linearity was observed over the range of 2-500 ng/mL with the correlation coefficient ranging from 0.9760 to 1.000. The limits of detection ranged from 0.2 to 1.2 ng/mL, and the limit of quantification was 4 ng/mL. These results confirm that computer-assisted design is an effective evaluation tool for molecularly imprinted polymers synthesis, and that molecularly imprinted solid-phase extraction can be applied to the simultaneous analysis of carbamates in environmental water.
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The growth of Scenedesmus sp. attachment on different materials surface.
Microb. Cell Fact.
PUBLISHED: 04-17-2014
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Microalgae has been concerned as a potential source of biodiesel in the recent years. However, it is costly to harvest microalgae as it is commonly cultured in water and the cells are too small to harvest. In order to reduce the cost of cultivation and harvesting, it is important to improve the biomass productivity of microalgae. Here, we utilized the attachment method to culture microalgae to cut off the cost of culture and harvest.
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Plasma n-3 and n-6 fatty acids and inflammatory markers in Chinese vegetarians.
Lipids Health Dis
PUBLISHED: 03-28-2014
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Polyunsaturated fatty acid (PUFA) intake favorably affects chronic inflammatory-related diseases such as cardiovascular disease; however, the relationship between the PUFA and inflammatory factors in the healthy vegetarians were not clear. We aimed to investigate the plasma fatty acids status, and its association with plasma inflammatory factors in Chinese vegetarians and omnivores.
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Conductive cotton prepared by polyaniline in situ polymerization using laccase.
Appl. Biochem. Biotechnol.
PUBLISHED: 03-19-2014
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The high-redox-potential catalyst laccase, isolated from Aspergillus, was first used as a biocatalyst in the oxidative polymerization of water-soluble conductive polyaniline, and then conductive cotton was prepared by in situ polymerization under the same conditions. The polymerization of aniline was performed in a water dispersion of sodium dodecylbenzenesulfonate (SDBS) micellar solution with atmospheric oxygen serving as the oxidizing agent. This method is ecologically clean and permits a greater degree of control over the kinetics of the reaction. The conditions for polyaniline synthesis were optimized. Characterizations of the conducting polyaniline and cotton were carried out using Fourier transform infrared spectroscopy, UV-vis spectroscopy, cyclic voltammetry, the fabric induction electrostatic tester, and the far-field EMC shielding effectiveness test fixture.
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Size-Dependent Nonlinear Optical Properties of Atomically Thin Transition Metal Dichalcogenide Nanosheets.
Small
PUBLISHED: 02-27-2014
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Size-dependent nonlinear optical properties of modification-free transition metal dichalcogenide (TMD) nanosheets are reported, including MoS2 , WS2 , and NbSe2 . Firstly, a gradient centrifugation method is demonstrated to separate the TMD nanosheets into different sizes. The successful size separation allows the study of size-dependent nonlinear optical properties of nanoscale TMD materials for the first time. Z-scan measurements indicate that the dispersion of MoS2 and WS2 nanosheets that are 50-60 nm thick leads to reverse saturable absorption (RSA), which is in contrast to the saturable absorption (SA) seen in the thicker samples. Moreover, the NbSe2 nanosheets show no size-dependent effects because of their metallic nature. The mechanism behind the size-dependent nonlinear optical properties of the semiconductive TMD nanosheets is revealed by transient transmission spectra measurements.
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Non-covalent immobilization of cellulases using the reversibly soluble polymers for bio-polishing of cotton fabric.
Biotechnol. Appl. Biochem.
PUBLISHED: 02-25-2014
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The hydrolytic reaction of cellulases can occur in the interior of cellulosic fibers, causing tensile strength loss of the fabrics. Cellulase immobilization is an approach to solve this problem, because enlarging the molecule size of cellulases will limit the hydrolysis to the surfaces of the fibers. In this study, commercial cellulases were non-covalently immobilized onto the reversibly soluble polymers (Eudragit S-100 and Eudragit L-100), respectively. The characteristics of cellulase-Eudragit S-100 (CES) and cellulase-Eudragit L-100 (CEL) were evaluated using Fourier transform infrared (FTIR) spectra, circular dichroism (CD) spectra, and fluorescence spectra. The CES showed higher stability than CEL and free cellulase especially at higher pH and temperature. CES and CEL retained 51%, and 42% of their original activities after three cycles of repeated uses, respectively. In addition, the effects of cellulase treatment on the cotton yarn and fabric have been investigated. The bending stiffness results showed that the cotton fabric samples treated with the free and immobilized cellulases were softer than untreated samples. However, less fiber damage in terms of weight loss and tensile strength of treated cotton was observed. This article is protected by copyright. All rights reserved.
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Association analysis of genes in serotonin pathway with attention and executive function in patients with bipolar affective disorder.
Compr Psychiatry
PUBLISHED: 02-18-2014
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The reason why it is difficult to identify susceptibility genes attributed to bipolar disorder (BPD) is the phenotypic heterogeneity. The use of endophenotypes has been advocated as one possible strategy to discovery cause variants of BPD.
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miR-888 in MCF-7 side population sphere cells directly targets E-cadherin.
J Genet Genomics
PUBLISHED: 02-01-2014
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Side population (SP) cells are a small subset of cells isolated from a cultured cancer cell line that exhibit characteristics similar to those of cancer stem cells (CSCs), such as high metastatic and tumorigenic potential. The molecular mechanisms that give rise to the malignant properties of SP cells are not clear. We isolated SP cells from the MCF-7 breast cancer cell line and profiled microRNA (miRNA) expression patterns between SP cell-derived spheroids and non-SP cells. SP spheroids were found to possess 42 up-regulated miRNAs and 27 down-regulated ones (above 5-fold changes). One of the up-regulated miRNAs, miR-888 computationally predicted to participate in the adherens junction (AJ) pathway, was investigated. Over-expression of miR-888 in MCF-7 cells reduced the mRNA levels of all four AJ pathway genes (E-cadherin, ACTG1, PTPRT and CDC42) that were selected for testing, whereas knocking down miR-888 reversed the trends. Western blot and flow cytometric quantitation of the membrane E-cadherin levels showed the same trend of change under these treatments. Luciferase reporter assay showed E-cadherin is a direct target of miR-888. As a potential role in intercellular adhesiveness and maintenance of malignant tissue architecture, the results indicate that miR-888 is a repressor of the AJ pathway in MCF-7 cells and that up-regulation of miR-888 contributes to aggressiveness in MCF-7 SP cells.
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TAZ promotes epithelial to mesenchymal transition via the upregulation of connective tissue growth factor expression in neuroblastoma cells.
Mol Med Rep
PUBLISHED: 01-14-2014
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Neuroblastoma (NB) is a neuroendocrine cancer that occurs most commonly in infants and young children. The Hippo signaling pathway regulates cell proliferation and apoptosis, and its primary downstream effectors are TAZ and yes?associated protein 1 (YAP). The effect of TAZ on the metastatic progression of neuroblastoma and the underlying mechanisms involved remain elusive. In the current study, it was determined by western blot analysis that the migratory and invasive properties of SK?N?BE(2) human neuroblastoma cells are associated with high expression levels of TAZ. Repressed expression of TAZ in SK?N?BE(2) cells was shown to result in a reduction in aggressiveness of the cell line, by Transwell migration and invasion assay. In contrast, overexpression of TAZ in SK?N?SH human neuroblastoma cells was shown by Transwell migration and invasion assays, and western blot analysis, to result in epithelial?mesenchymal transition (EMT) and increased invasiveness. Mechanistically, the overexpression of TAZ was demonstrated to upregulate the expression levels of connective tissue growth factor (CTGF), by western blot analysis and chromatin immunoprecipitation assay, while the knockdown of TAZ downregulated it. Furthermore, TAZ was shown by luciferase assay to induce CTGF expression by modulating the activation of the TGF??/Smad3 signaling pathway. In conclusion, the present study is, to the best of our knowledge, the first to demonstrate that the overexpression of TAZ induces EMT, increasing the invasive abilities of neuroblastoma cells. This suggests that TAZ may serve as a potential target in the development of novel therapies for the treatment of neuroblastoma.
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Inhibitory effects of Dendrobium candidum Wall ex Lindl. on azoxymethane- and dextran sulfate sodium-induced colon carcinogenesis in C57BL/6 mice.
Oncol Lett
PUBLISHED: 01-08-2014
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Dendrobium candidum Wall ex Lindl. was purchased for the evaluation of azoxymethane (AOM)- and dextran sulfate sodium (DSS)-induced colon carcinogenesis in C57BL/6 mice. The body weights of the AOM- and DSS-induced colon cancer control groups were lighter than those of the untreated mice. D. candidum increased the body weights of the mice compared with the control group, and reduced the levels of the serum proinflammatory cytokines, IL-6, IL-12, TNF-? and IFN-?, compared with the colon cancer control group. Reverse transcription-polymerase chain reaction and western blot analyses of the apoptotic-related genes, bax, bcl-2, caspase-3 and caspase-9, were performed in the colon tissues. The high-concentration D. candidum group showed a significant increase in the mRNA and protein expression levels of bax, caspase-3 and caspase-9 and decreased expression levels of bcl-2 compared with the control group. These results indicate that D. candidum Wall ex Lindl. exhibits preventive effects against colon carcinogenesis in mice.
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Isolation, Purification and Molecular Mechanism of a Peanut Protein-Derived ACE-Inhibitory Peptide.
PLoS ONE
PUBLISHED: 01-01-2014
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Although a number of bioactive peptides are capable of angiotensin I-converting enzyme (ACE) inhibitory effects, little is known regarding the mechanism of peanut peptides using molecular simulation. The aim of this study was to obtain ACE inhibiting peptide from peanut protein and provide insight on the molecular mechanism of its ACE inhibiting action. Peanut peptides having ACE inhibitory activity were isolated through enzymatic hydrolysis and ultrafiltration. Further chromatographic fractionation was conducted to isolate a more potent peanut peptide and its antihypertensive activity was analyzed through in vitro ACE inhibitory tests and in vivo animal experiments. MALDI-TOF/TOF-MS was used to identify its amino acid sequence. Mechanism of ACE inhibition of P8 was analyzed using molecular docking and molecular dynamics simulation. A peanut peptide (P8) having Lys-Leu-Tyr-Met-Arg-Pro amino acid sequence was obtained which had the highest ACE inhibiting activity of 85.77% (half maximal inhibitory concentration (IC50): 0.0052 mg/ml). This peanut peptide is a competitive inhibitor and show significant short term (12 h) and long term (28 days) antihypertensive activity. Dynamic tests illustrated that P8 can be successfully docked into the active pocket of ACE and can be combined with several amino acid residues. Hydrogen bond, electrostatic bond and Pi-bond were found to be the three main interaction contributing to the structural stability of ACE-peptide complex. In addition, zinc atom could form metal-carboxylic coordination bond with Tyr, Met residues of P8, resulting into its high ACE inhibiting activity. Our finding indicated that the peanut peptide (P8) having a Lys-Leu-Tyr-Met-Arg-Pro amino acid sequence can be a promising candidate for functional foods and prescription drug aimed at control of hypertension.
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A Novel PCR-Based Approach to Discover miRNA Target Genes.
Int J Med Sci
PUBLISHED: 01-01-2014
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MiRNAs are potent regulators of gene expression, and most miRNAs have from several to several thousands of gene targets. Validating the numerous gene targets of a given miRNA remains challenging despite the existence of various tools and databases that predict candidate gene-miRNA pairs. In the present study, we present a high-throughput but flexible method that applies a PCR-based application to simulate the binding of miRNAs to their gene targets. Using hsa-miR-377 as an illustrative example, our method was able to identify 13 potential targets of hsa-miR-377. Moreover, our results include 2 genes (SOD2 and PPM1A) that have already been verified as targets of hsa-miR-377. Our method may provide an alternative way of identifying the gene targets of miRNAs for future research.
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MiR-181b-5p Downregulates NOVA1 to Suppress Proliferation, Migration and Invasion and Promote Apoptosis in Astrocytoma.
PLoS ONE
PUBLISHED: 01-01-2014
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MicroRNAs (miRNAs) are small, short noncoding RNAs that modulate the expression of numerous genes by targeting their mRNA. Numerous abnormal miRNA expression patterns are observed in various human malignancies, and certain miRNAs can act as oncogenes or tumor suppressors. Astrocytoma, the most common neuroepithelial cancer, represents the majority of malignant brain tumors in humans. In our previous studies, we found that the downregulation of miR-181b-5p in astrocytomas is associated with a poor prognosis. The aim of the present study was to investigate the functional role of miR-181b-5p and its possible target genes. miR-181b-5p was significantly downregulated in astrocytoma specimens, and the reduced expression of miR-181b-5p was inversely correlated with the clinical stage. The ectopic expression of miR-181b-5p inhibited proliferation, migration and invasion and induced apoptosis in astrocytoma cancer cells in vitro. The NOVA1 (neuro-oncological ventral antigen 1) gene was further identified as a novel direct target of miR-181b-5p. Specifically, miR-181b-5p bound directly to the 3'-untranslated region (UTR) of NOVA1 and suppressed its expression. In clinical specimens, NOVA1 was overexpressed, and its protein levels were inversely correlated with miR-181b-5p expression. Furthermore, the changing level of NOVA1 was significantly associated with a poor survival outcome. Similar to restoring miR-181b-5p expression, downregulating NOVA1 inhibited cell growth, migration and invasion. Overexpression of NOVA1 reversed the inhibitory effects of miR-181b-5p. Our results indicate that miR-181b-5p is a tumor suppressor in astrocytoma that inhibits tumor progression by targeting NOVA1. These findings suggest that miR-181b-5p may serve as a novel therapeutic target for astrocytoma.
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Caffeine Accelerates Recovery from General Anesthesia.
J. Neurophysiol.
PUBLISHED: 12-26-2013
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General anesthetics inhibit neurotransmitter release from both neurons and secretory cells. If inhibition of neurotransmitter release is part of an anesthetics mechanism of action, then drugs that facilitate neurotransmitter release may aid in reversing general anesthesia. Drugs that elevate intracellular cAMP levels are known to facilitate neurotransmitter release. Three cAMP elevating drugs (forskolin, theophylline and caffeine) were tested; all three drugs reversed the inhibition of neurotransmitter release produced by isoflurane in PC12 cells in vitro. The drugs were tested in isoflurane anesthetized rats. Animals were injected with either saline or saline containing drug. All three drugs dramatically accelerated recovery from isoflurane anesthesia, but caffeine was most effective. None of the drugs, at the concentrations tested, had significant effects on breathing rates, O2 saturation, heart rate or blood pressure in anesthetized animals. Caffeine alone was tested on propofol anesthetized rats where it dramatically accelerated recovery from anesthesia. Caffeines ability to accelerate recovery from anesthesia for different chemical classes of anesthetics, isoflurane and propofol, opens the possibility that it will do so for all commonly used general anesthetics, although additional studies will be required to determine whether this is in fact the case. Because anesthesia in rodents is thought to be similar to that in humans, these results suggest that caffeine might allow for rapid and uniform emergence from general anesthesia in human patients.
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Differential diagnosis of pulmonary lesions by parametric imaging in (18)F-FDG PET/CT dynamic multi-bed scanning.
J BUON
PUBLISHED: 12-18-2013
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Purpose: Benign and malignant pulmonary lesions are not easy to distinguish in a clinical setting. We investigated the feasibility of using parametric imaging of the rate constant Ki to diagnose the nature of pulmonary lesions. Methods: Dynamic multi-bed scanning followed by a routine examination was performed on 21 patients with pulmonary lesions who were divided into two groups with malignant or benign lesions based on biopsy and follow-up. The number of patients in the malignant and benign groups were 10 with 15 lesions and 11 with 14 lesions, respectively. The left ventricular blood pool was used for an image-derived input function. The influx rate constant Ki of the pulmonary lesions and parametric images was generated with the Patlak plot method, and the inter-group differences for Ki, maximum standardized uptake value (SUVmax), and the time-activity curves (TAC) of fluorine-18-fludeoxyglucose ((18)F-FDG) were analyzed. At the same time, we investigated the correlation of Ki to SUVmax. Results: The maximum diameters of the pulmonary lesions were not significantly different between the malignant and benign groups (p>0.05). Ki and SUVmax were significantly higher in malignant lesions compared to benign lesions (p<0.05). Ki was highly correlated with SUVmax in pulmonary lesions (r=0.815, p<0.01). The malignant lesions showed gradually increasing TAC, and benign lesions exhibited gradually decreasing curves. The parametric images of Ki were useful to distinguish malignant lesions from normal tissue. Conclusion: Our results indicate that Ki parametric imaging in (18)F-FDG PET/computed tomography (CT) dynamic multi-bed scanning may be useful in the differential diagnosis of pulmonary lesions.
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The combined toxicity assessment of carp (Cyprinus carpio) acetylcholinesterase activity by binary mixtures of chlorpyrifos and four other insecticides.
Ecotoxicology
PUBLISHED: 12-12-2013
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Mixtures of organophosphate (OP) and carbamate (CB) insecticides are commonly detected in freshwater habitats. These insecticides inhibit the activity of acetylcholinesterase (AChE) and have potential to interfere with behaviors that may be essential for survival of species. Although the effects of individual anticholinesterase insecticides on aquatic species have been studied for decades, the combined toxicity of mixtures is still poorly understood. In the present study, we assessed whether pesticides in a mixture act in isolation (resulting in additive AChE inhibition) or whether components interact to produce either antagonistic or synergistic toxicity. Brain AChE inhibition in carp (Cyprinus carpio L.) exposed to a series of concentrations of the OP (chlorpyrifos, malathion and triazophos) as well as the CB (fenobucarb and carbosulfan) were measured. The concentration addition (CA) model and the isobole method were used to determine whether toxicological responses to binary mixtures of pesticides. In 50:50 % effect mixtures, the observed combined toxicity of chlorpyrifos and malathion was significantly higher than observed and was considered as synergistic. For equivalent dose mixtures, when chlorpyrifos mixed with fenobucarb or malathion, the observed toxicities were significantly higher than predicted, suggesting synergistic joint actions. The rest five binary combinations exhibited concentration additive or slight antagonistic joint actions. The CA model and the isobole method provided estimates of mixture toxicity that did not markedly underestimate the measured toxicity, therefore these methods are suitable to use in ecological risk assessments of pesticide mixtures.
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Sirt2 functions in spindle organization and chromosome alignment in mouse oocyte meiosis.
FASEB J.
PUBLISHED: 12-12-2013
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Sirtuins have been widely reported to be involved in multiple biological processes; however, their function in oocyte meiosis has not been. Here, by confocal scanning and quantitative analysis, we show that specific depletion of Sirt2 in mouse oocytes results in spindle defects and chromosome disorganization (35.5±8.7 vs. 9.6±3.8% control; P<0.05), with impaired microtubule-kinetochore interaction. Moreover, knockdown and overexpression experiments reveal that Sirt2 modulates the acetylation status of histone H4K16 and ?-tubulin in oocytes, which may in part mediate the defective phenotypes described above by influencing microtubule dynamics and kinetochore function. Finally, we find lower Sirt2 protein level in oocytes from aged mice by immunoblotting and that maternal age-associated meiotic defects can be ameliorated through overexpression of Sirt2 (33.2±5.1% old vs.12.7±5.2% old+Sirt2; P<0.05), providing support for the hypothesis that decreased Sirt2 is one of a number of factors contributing to oocyte age-dependent deficits. In summary, our data indicate a role for Sirt2 during oocyte meiosis and uncover a striking beneficial effect of increased Sirt2 expression on aged oocytes.-Zhang, L., Hou, X., Ma, R., Moley, K., Schedl, T., Wang, Q. Sirt2 functions in spindle organization and chromosome alignment in mouse oocyte meiosis.
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In vivo mechanical properties loss and the bone-implants interface strength of AZ31B magnesium alloy screws with Si-containing coating.
Acta Biomater
PUBLISHED: 12-09-2013
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In this study the mechanical properties loss and the interface strength of coated AZ31B magnesium alloy (magnesium-aluminum alloy) screws with surrounding host tissues were investigated and compared with naked AZ31B, degradable polymer and biostable titanium alloy screws in a rabbit animal model after 1, 4, 12 and 21weeks implantation. The interface strength was evaluated by the extraction torque to wring out the screws. The mechanical properties loss over time was displayed by one-point bending load loss of the screws after wrung out at different time. Silicon(Si)-containing coating was prepared on AZ31B samples, which effectively decreased the degradation rate of AZ31B and improved its biological properties. The extraction torque of Ti6Al4V, PLLA (Poly-L-lactide) and coated AZ31B increased obviously from 1 week to 4 weeks postimplantation, indicating a rapid osteosynthesis process during the 3 weeks. The extraction torque of coated AZ31B increased with implantation time, higher than those of PLLA from 4 weeks implantation, catching up with that of Ti6Al4V at 12 weeks and higher at 21 weeks. The bending loads of naked AZ31B and PLLA screws degraded sharply after implantion, and that of coated AZ31B degraded more slowly. The biodegradation mechanism, the coating to control the degradation rate and the bioactivity of magnesium alloys influencing the mechanical properties loss over time and bone-implant interface strength were discussed in this study and it is thought that a proper degradation rate will make the corrosion biodegradation mechanism and the bioactivity of magnesium alloys more beneficial for the mechanical performance and their application in clinic.
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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.