► Overview of recent progress on the production and modification of poly(vinylidene fluoride) (PVDF) membranes. ► Crystalline properties, thermal stability and chemical resistance were firstly ...introduced. ► Production methods of PVDF membranes via phase inversion were reviewed. ► Various hydrophilic modification approaches such as surface modification and blending modification were investigated.
This article provides a comprehensive overview of recent progress on the production and modification of poly(vinylidene fluoride) (PVDF) membranes for liquid–liquid or liquid–solid separation. The crystalline properties, thermal stability and chemical resistance were firstly considered in this review, followed by the production methods of PVDF membranes via phase inversion including immersion precipitation and thermally induced phase separation. Various hydrophilic modification approaches such as surface modification and blending modification for improving the fouling resistance of PVDF membranes were subsequently reviewed. Finally, in the light of the anticipated role of PVDF as a superior membrane material, future prospects on the production and modification of PVDF membranes were suggested.
Minichromosome maintenance (MCM) proteins 2-7 are important in DNA replication licensing. Functional roles beyond licensing are speculated. In addition, significances in medulloblastoma (MB) remain ...unclear. In this study, we showed the frequent deregulation of MCM2 and MCM3 expression in 7 MB cell lines and 31 clinical samples. Moreover, DAOY and ONS76 and the clinical samples expressed elevated MCM7 transcripts with genomic gain of the gene. Immunopositivity restricted to tumor cells was found in 41, 37 and 53 out of 73 MB cases for MCM2, MCM3 and MCM7, respectively. High-MCM3 expression was associated with poor prognosis. Knockdowns of these MCMs significantly inhibited anchorage-dependent and -independent MB cell growth. The inhibition of MCM3 expression by small interfering RNA knockdown was related to G1 arrest with reduced cyclin A expression, whereas the MCM2- and MCM7-knocked-down cells arrested at G2/M with increased cyclin A expression. Interestingly, we demonstrated the links of these MCMs with cell migration and invasion using wound-healing and Transwell migration/invasion assays. Exogenous overexpression of MCM2, MCM3 and MCM7 increased anchorage-independent cell growth, and also cell migration and invasion capabilities in MB cells. The knockdown reduced the number of filopodial cells and the cells with intense stress fibers by blocking cdc42 and Rho activation. Taken together, deregulation of MCM2, MCM3 and MCM7 expression might be involved in MB tumorigenesis and we revealed undefined roles of these MCMs in control of MB cell migration and invasion.
Many schizophrenia susceptibility loci have been identified through genome-wide association studies (GWASs) in European populations. However, until recently, schizophrenia GWASs in non-European ...populations were limited to small sample sizes and have yielded few loci associated with schizophrenia. To identify genetic risk variations for schizophrenia in the Han Chinese population, we performed a two-stage GWAS of schizophrenia comprising 4384 cases and 5770 controls, followed by independent replications of 13 single-nucleotide polymorphisms in an additional 4339 schizophrenia cases and 7043 controls of Han Chinese ancestry. Furthermore, we conducted additional analyses based on the results in the discovery stage. The combined analysis confirmed evidence of genome-wide significant associations in the Han Chinese population for three loci, at 2p16.1 (rs1051061, in an exon of VRK2, P=1.14 × 10
, odds ratio (OR)=1.17), 6p22.1 (rs115070292 in an intron of GABBR1, P=4.96 × 10
, OR=0.77) and 10q24.32 (rs10883795 in an intron of AS3MT, P=7.94 × 10
, OR=0.87; rs10883765 at an intron of ARL3, P=3.06 × 10
, OR=0.87). The polygenic risk score based on Psychiatric Genomics Consortium schizophrenia GWAS data modestly predicted case-control status in the Chinese population (Nagelkerke R
: 1.7% ~5.7%). Our pathway analysis suggested that neurological biological pathways such as GABAergic signaling, dopaminergic signaling, cell adhesion molecules and myelination pathways are involved in schizophrenia. These findings provide new insights into the pathogenesis of schizophrenia in the Han Chinese population. Further studies are needed to establish the biological context and potential clinical utility of these findings.
Smallest Algae Thrive As the Arctic Ocean Freshens Li, William K.W; McLaughlin, Fiona A; Lovejoy, Connie ...
Science (American Association for the Advancement of Science),
10/2009, Letnik:
326, Številka:
5952
Journal Article
Recenzirano
As climate changes and the upper Arctic Ocean receives more heat and fresh water, it becomes more difficult for mixing processes to deliver nutrients from depth to the surface for phytoplankton ...growth. Competitive advantage will presumably accrue to small cells because they are more effective in acquiring nutrients and less susceptible to gravitational settling than large cells. Since 2004, we have discerned an increase in the smallest algae and bacteria along with a concomitant decrease in somewhat larger algae. If this trend toward a community of smaller cells is sustained, it may lead to reduced biological production at higher trophic levels.
An overview of Sun–Sky Radiometer Observation Network (SONET) measurements in China is presented. Based on observations at 16 distributed SONET sites in China, atmospheric aerosol parameters are ...acquired via standardization processes of operational measurement, maintenance, calibration, inversion, and quality control implemented since 2010. A climatology study is performed focusing on total columnar atmospheric aerosol characteristics, including optical (aerosol optical depth, ÅngstrÖm exponent, fine-mode fraction, single-scattering albedo), physical (volume particle size distribution), chemical composition (black carbon; brown carbon; fine-mode scattering component, coarse-mode component; and aerosol water), and radiative properties (aerosol radiative forcing and efficiency). Data analyses show that aerosol optical depth is low in the west but high in the east of China. Aerosol composition also shows significant spatial and temporal variations, leading to noticeable diversities in optical and physical property patterns. In west and north China, aerosols are generally affected by dust particles, while monsoon climate and human activities impose remarkable influences on aerosols in east and south China. Aerosols in China exhibit strong light-scattering capability and result in significant radiative cooling effects.
Objective. To examine the distribution of traditional and novel risk factors of cardiovascular disease (CVD) in patients with PsA compared with healthy controls. Methods. We compared risk factors for ...CVD between 102 consecutive PsA patients and 82 controls, adjusting for BMI. We also assessed the role of inflammation on the CVD risk factor by using a BMI and high-sensitivity CRP (hsCRP)-adjusted model. Results. The BMI of PsA patients were significantly higher than healthy controls. After adjusting for the BMI, PsA patients still have a higher prevalence of diabetes mellitus (DM) odds ratio (OR) 9.27, 95% CI 2.09, 41.09) and hypertension (OR 3.37, 95% CI 1.68, 6.72), but a lower prevalence of low high density lipoprotein (HDL) cholesterol (OR 0.16, 95% CI 0.07, 0.41). PsA patients have significantly increased systolic and diastolic blood pressures, insulin resistance and inflammatory markers (hsCRP and white cell count) compared to controls. PsA patients have higher HDL cholesterol and apolipoprotein (Apo) A1 levels; and lower total cholesterol (TC) and low density lipoprotein cholesterol levels; and a lower TC/HDL ratio. However, the Apo B level (P < 0.05), and the Apo B/Apo A1 ratio (P = 0.07) were higher in PsA patients. Further adjustment for hsCRP level rendered the differences in the prevalence of hypertension and DM; the TC, and sugar levels; and white cell count non-significant between the two groups; while the differences in other parameters remained significant. Conclusion. These data support the hypothesis that PsA may be associated with obesity, hypertension, dyslipidaemia and insulin resistance because of the shared inflammatory pathway.
Increasing global temperatures are having a profound impact in the Arctic, including the dramatic loss of multiyear sea ice in 2007 that has continued to the present. The majority of life in the ...Arctic is microbial and the consequences of climate-mediated changes on microbial marine food webs, which are responsible for biogeochemical cycling and support higher trophic levels, are unknown. We examined microbial communities over time by using high-throughput sequencing of microbial DNA collected between 2003 and 2010 from the subsurface chlorophyll maximum (SCM) layer of the Beaufort Sea (Canadian Arctic). We found that overall this layer has freshened and concentrations of nitrate, the limiting nutrient for photosynthetic production in Arctic seas, have decreased. We compared microbial communities from before and after the record September 2007 sea ice minimum and detected significant differences in communities from all three domains of life. In particular, there were significant changes in species composition of Eukarya, with ciliates becoming more common and heterotrophic marine stramenopiles (MASTs) accounting for a smaller proportion of sequences retrieved after 2007. Within the Archaea, Marine Group I Thaumarchaeota, which earlier represented up to 60% of the Archaea sequences in this layer, have declined to <10%. Bacterial communities overall were less diverse after 2007, with a significant decrease of the Bacteroidetes. These significant shifts suggest that the microbial food webs are sensitive to physical oceanographic changes such as those occurring in the Canadian Arctic over the past decade.
Objectives. The treatment of pure membranous (class V) lupus nephropathy remains unsatisfactory. We studied the efficacy and safety of tacrolimus in the treatment of membranous nephritis secondary to ...SLE. Methods. We recruited 18 consecutive SLE patients (tacrolimus group) with recently confirmed biopsy-proven class V lupus nephritis. They were treated with a tailing dose of oral prednisolone and tacrolimus 0.1–0.2 mg/kg/day for 6 months, followed by maintenance prednisolone and AZA. The rate of resolution of proteinuria and SLEDAI were compared with 19 historical controls treated with oral cyclophosphamide or AZA (control group). All patients were followed for 12 months. Results. Baseline clinical characteristics were comparable between the groups. For the tacrolimus group, the complete and partial remission rates were 27.8 and 50.0%, respectively at 12 weeks; for the control group, they were 15.8 and 47.4%, respectively (overall chi-square test, P = 0.5). However, tacrolimus group had faster resolution of proteinuria than the control group by the general linear model with repeated measures (P = 0.032). At 12 weeks, proteinuria was reduced by 76.2 ± 17.0% for the tacrolimus group and 47.1 ± 51.1% for the control group (P = 0.028). Serial change in renal function and SLEDAI score did not differ between the groups. During the study period, four patients of the tacrolimus group, and 11 of the control group, developed lupus flare (P = 0.027). There was no serious adverse effect in the tacrolimus group. Conclusions. A 6-month course of tacrolimus is a safe and effective treatment of pure class V (membranous) lupus nephritis. As compared with conventional cytotoxic treatment, tacrolimus possibly results in a faster resolution of proteinuria, and a lower risk of lupus flare within 1 yr. The long-term effect and optimal regimen of tacrolimus require further study.
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