479 research outputs found

    Calculation and Analysis of the Instream Ecological Flow for the Irtysh River

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    AbstractInstream ecological flow is essential determinant of river health. In this paper, the monthly minimum flow calculation method, the (new) monthly frequency calculation method were applied to calculate and evaluate the minimum instream ecological flow and the optimal instream ecological flow for the Irtysh River, and the different criteria of instream ecological flow was calculated by the improved Tennant method. It is expected to provide a scientific basis for the reasonable allocation of water resource in Irtysh River basin by calculating the instream ecological flow

    Controlled release of paclitaxel from a self-assembling peptide hydrogel formed in situ and antitumor study in vitro

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    Background: A nanoscale injectable in situ-forming hydrogel drug delivery system was developed in this study. The system was based on a self-assembling peptide RADA16 solution, which can spontaneously form a hydrogel rapidly under physiological conditions. We used the RADA16 hydrogel for the controlled release of paclitaxel (PTX), a hydrophobic antitumor drug. Methods: The RADA16-PTX suspension was prepared simply by magnetic stirring, followed by atomic force microscopy, circular dichroism analysis, dynamic light scattering, rheological analysis, an in vitro release assay, and a cell viability test. Results: The results indicated that RADA16 and PTX can interact with each other and that the amphiphilic peptide was able to stabilize hydrophobic drugs in aqueous solution. The particle size of PTX was markedly decreased in the RADA16 solution compared with its size in water. The RADA16-PTX suspension could form a hydrogel in culture medium, and the elasticity of the hydrogel showed a positive correlation with peptide concentration. In vitro release measurements indicated that hydrogels with a higher peptide concentration had a longer half-release time. The RADA16-PTX hydrogel could effectively inhibit the growth of the breast cancer cell line, MDA-MB-435S, in vitro, and hydrogels with higher peptide concentrations were more effective at inhibiting tumor cell proliferation. The RADA16-PTX hydrogel was effective at controlling the release of PTX and inhibiting tumor cell growth in vitro. Conclusion: Self-assembling peptide hydrogels may work well as a system for drug delivery

    General practitioners' knowledge of ageing and attitudes towards older people in China

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    Author version made available in accordance with Publisher copyright. 12 month embargo from date of publication [Oct 9 2013]. This is the accepted version of the following article: [Yang, Y., Xiao, L. D., Ullah, S. and Deng, L. (2013), General practitioners' knowledge of ageing and attitudes towards older people in China. Australasian Journal on Ageing. ], which has been published in final form at [doi: 10.1111/ajag.12105]. In addition, authors may also transmit, print and share copies with colleagues, provided that there is no systematic distribution of the submitted version, e.g. posting on a listserve, network or automated delivery.Aim To explore general practitioners (GPs)' knowledge of ageing, attitudes towards older people and factors affecting their knowledge and attitudes in a Chinese context. Methods Four hundred GPs were surveyed using the Chinese version of the Aging Semantic Differential (CASD) and the Chinese version of the Facts on Aging Quiz (CFAQ1) scale. Results The CASD scores indicated that GPs had a neutral attitude towards older people. The CFAQ1 scores indicated a low level of knowledge about ageing. GPs' awareness of the mental and social facts of ageing was poorer compared to that of physical facts. Male GPs had a significantly higher negative bias score than female GPs. No other variables had a statistically significant influence on knowledge and attitudes. Conclusions The findings suggest the need for education interventions for GPs regarding knowledge of ageing and also provide evidence to guide future development of continuing medical programs for this group of medical doctors

    Heterologous protein display on the cell surface of lactic acid bacteria mediated by the s-layer protein

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    <p>Abstract</p> <p>Background</p> <p>Previous studies have revealed that the C-terminal region of the S-layer protein from <it>Lactobacillus </it>is responsible for the cell wall anchoring, which provide an approach for targeting heterologous proteins to the cell wall of lactic acid bacteria (LAB). In this study, we developed a new surface display system in lactic acid bacteria with the C-terminal region of S-layer protein SlpB of <it>Lactobacillus crispatus </it>K2-4-3 isolated from chicken intestine.</p> <p>Results</p> <p>Multiple sequence alignment revealed that the C-terminal region (LcsB) of <it>Lb. crispatus </it>K2-4-3 SlpB had a high similarity with the cell wall binding domains S<sub>A </sub>and CbsA of <it>Lactobacillus acidophilus </it>and <it>Lb. crispatus</it>. To evaluate the potential application as an anchoring protein, the green fluorescent protein (GFP) or beta-galactosidase (Gal) was fused to the N-terminus of the LcsB region, and the fused proteins were successfully produced in <it>Escherichia coli</it>, respectively. After mixing them with the non-genetically modified lactic acid bacteria cells, the fused GFP-LcsB and Gal-LcsB were functionally associated with the cell surface of various lactic acid bacteria tested. In addition, the binding capacity could be improved by SDS pretreatment. Moreover, both of the fused proteins could simultaneously bind to the surface of a single cell. Furthermore, when the fused DNA fragment of <it>gfp:lcsB </it>was inserted into the <it>Lactococcus lactis </it>expression vector pSec:Leiss:Nuc, the GFP could not be secreted into the medium under the control of the <it>nisA </it>promoter. Western blot, in-gel fluorescence assay, immunofluorescence microscopy and SDS sensitivity analysis confirmed that the GFP was successfully expressed onto the cell surface of <it>L. lactis </it>with the aid of the LcsB anchor.</p> <p>Conclusion</p> <p>The LcsB region can be used as a functional scaffold to target the heterologous proteins to the cell surfaces of lactic acid bacteria <it>in vitro </it>and <it>in vivo</it>, and has also the potential for biotechnological application.</p

    Nurse-led cognitive screening model for older adults in primary care

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    Author version made available in accordance with publisher copyright. Under 12 month embargo from date of publication [26 September 2014]. This is the accepted version of the following article: [Yang, Y., Xiao, L. D., Deng, L., Wang, Y., Li, M. and Ullah, S. (2014), Nurse-led cognitive screening model for older adults in primary care. Geriatrics & Gerontology International.], which has been published in final form at [doi: 10.1111/ggi.12339]. In addition, authors may also transmit, print and share copies with colleagues, provided that there is no systematic distribution of the submitted version, e.g. posting on a listserve, network or automated delivery.Aim The present study aimed to establish a nurse-led cognitive screening model for community-dwelling older adults with subjective memory complaints from seven communities in Chongqing, China, and report the findings of this model. Methods Screenings took place from July 2012 to June 2013. Cognitive screening was incorporated into the annual health assessment for older adults with subjective memory complaints in a primary care setting. Two community nurses were trained to implement the screening using the Mini-Mental State Examination and Montreal Cognitive Assessment. Results Of 733 older adults, 495 (67.5%) reported having subjective memory complaints. Of the 249 individuals who participated in the cognitive screening, 102 (41%) had mild cognitive impairment, whereas 32 (12.9%) had cognitive impairment. A total of 80 participants (78.4%) with mild cognitive impairment agreed to participate in a memory support program. Participants with cognitive impairment were referred to specialists for further examination and diagnosis; only one reported that he had seen a specialist and had been diagnosed with dementia. Conclusions Incorporating cognitive screening into the annual health assessment for older adults with subjective memory complaints was feasible, though referral rates from primary care providers remained unchanged. The present study highlights the urgent need for simple screenings as well as community-based support services in primary care for older adults with cognitive or mild cognitive impairments

    A broad-host-range lytic phage vB_VhaS-R18L as a candidate against vibriosis

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    Vibriosis is one of the most common bacterial diseases that cause high rates of mortality and considerable economic losses in aquaculture. Phage therapy has been considered as a promising alternative method to antibiotics in the biocontrol of infectious diseases. Genome sequencing and characterization of the phage candidates are prerequisites before field applications to ensure environmental safety. In this study, a lytic phage, named vB_VhaS-R18L (R18L), was isolated from the coastal seawater of Dongshan Island, China. The phage was characterized in terms of morphology, genetic content, infection kinetics, lytic profile, and virion stability. Transmission electronic microscopy indicated that R18L is siphovirus-like, comprising an icosahedral head (diameter 88.6 ± 2.2 nm) and a long noncontractile tail (225 × 11 nm). Genome analysis indicated R18L to be a double-stranded DNA virus with a genome size of 80,965 bp and a G + C content of 44.96%. No genes that encode known toxins or genes implicated in lysogeny control were found in R18L. A one-step growth experiment showed that R18L had a latent period of approximately 40 min and a burst size of 54 phage particles per infected cell. R18L showed lytic activity against a wide range of at least five Vibrio species (V. alginolyticus, V. cholerae, V. harveyi, V. parahemolyticus, and V. proteolyticus). R18L was relatively stable at pH 6–11 and at temperatures ranging from 4°C to 50°C. The broad lytic activity across Vibrio species and the stability in the environment make R18L a potential candidate for phage therapy in controlling vibriosis in aquaculture systems

    Soil pH, total phosphorus, climate and distance are the major factors influencing microbial activity at a regional spatial scale

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    Considering the extensive functional redundancy in microbial communities and great difficulty in elucidating it based on taxonomic structure, studies on the biogeography of soil microbial activity at large spatial scale are as important as microbial community structure. Eighty-four soil samples were collected across a region from south to north China (about 1,000 km) to address the questions if microbial activity displays biogeographic patterns and what are driving forces. These samples represented different soil types, land use and climate. Redundancy analysis and nonmetric multidimensional scaling clearly revealed that soil microbial activities showed distinct differentiation at different sites over a regional spatial scale, which were strongly affected by soil pH, total P, rainfall, temperature, soil type and location. In addition, microbial community structure was greatly influenced by rainfall, location, temperature, soil pH and soil type and was correlated with microbial activity to some extent. Our results suggest that microbial activities display a clear geographic pattern that is greatly altered by geographic distance and reflected by climate, soil pH and total P over large spatial scales. There are common (distance, climate, pH and soil type) but differentiated aspects (TP, SOC and N) in the biogeography of soil microbial community structure and activity

    Global well-posedness of a class of fourth-order strongly damped nonlinear wave equations

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    Global well-posedness and finite time blow up issues for some strongly damped nonlinear wave equation are investigated in the present paper. For subcritical initial energy by employing the concavity method we show a finite time blow up result of the solution. And for critical initial energy we present the global existence, asymptotic behavior and finite time blow up of the solution in the framework of the potential well. Further for supercritical initial energy we give a sufficient condition on the initial data such that the solution blows up in finite time

    Interleukin-35 Dampens CD8+ T Cells Activity in Patients With Non-viral Hepatitis-Related Hepatocellular Carcinoma

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    Interleukin (IL)-35 is a newly identified IL-12 cytokine family member, which has been demonstrated to induce immunotolerance by suppression of CD8+ T cells function in chronic viral hepatitis. However, the role of IL-35 in modulating CD8+ T cells activity in non-viral hepatitis-related hepatocellular carcinoma (HCC) was not fully elucidated. Forty-four patients with non-viral hepatitis-related HCC and 20 healthy individuals were enrolled. Serum IL-35 concentration was measured by ELISA. CD8+ T cells were purified from peripheral bloods and liver tissues. mRNA expression of cytotoxic/inhibitory molecules in CD8+ T cells with IL-35 stimulation was semi-quantified by real-time PCR. Direct and indirect contact co-culture systems of CD8+ T cells and HCC cell lines were set up. The modulatory function of IL-35 on peripheral and liver-resident CD8+ T cells was assessed by measurement of lactate dehydrogenase release and cytokine production in the co-culture supernatants. Serum IL-35 was notably elevated in HCC patients, while effective anti-tumor therapies down-regulated IL-35 concentration. Recombinant IL-35 stimulation suppressed cytotoxicity and proinflammatory cytokine secretion of peripheral and liver-resident CD8+ T cells in direct and indirect contact co-culture systems. This process was accompanied by reduction of perforin expression and interferon-γ production, as well as programmed death-1 and cytotoxic T-lymphocyte-associated protein 4 elevation in CD8+ T cells. The current data suggested that IL-35 inhibited both cytolytic and non-cytolytic function of CD8+ T cells to non-viral hepatitis-related HCC probably via repression of perforin expression. IL-35 might be considered to be one of the therapeutic targets for patients with HCC
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