156 research outputs found

    Direct observation of local K variation and its correlation to electronic inhomogeneity in (Ba1-xKx)Fe2As2 Pnictide

    Get PDF
    Local fluctuations in the distribution of dopant atoms are a suspected cause of nanoscale electronic disorder or phase separation observed within the pnictide superconductors. Atom probe tomography results present the first direct observations of dopant nano-clustering in a K-doped 122-phase pnictides. First-principles calculations suggest the coexistence of static magnetism and superconductivity on a lattice parameter length scale over a large range of doping concentrations. Collectively, our results provide evidence for a mixed scenario of phase coexistence and phase separation originating from variation of dopant atom experiments distroibutions.Comment: 4 pages, 4 figures and 1 table, accepted by Physical Review Letter 201

    Functionally Redundant RXLR Effectors from <em>Phytophthora infestans</em> Act at Different Steps to Suppress Early flg22-Triggered Immunity

    Get PDF
    Genome sequences of several economically important phytopathogenic oomycetes have revealed the presence of large families of so-called RXLR effectors. Functional screens have identified RXLR effector repertoires that either compromise or induce plant defense responses. However, limited information is available about the molecular mechanisms underlying the modes of action of these effectors in planta. The perception of highly conserved pathogen- or microbe-associated molecular patterns (PAMPs/MAMPs), such as flg22, triggers converging signaling pathways recruiting MAP kinase cascades and inducing transcriptional re-programming, yielding a generic anti-microbial response. We used a highly synchronizable, pathogen-free protoplast-based assay to identify a set of RXLR effectors from Phytophthora infestans (PiRXLRs), the causal agent of potato and tomato light blight that manipulate early stages of flg22-triggered signaling. Of thirty-three tested PiRXLR effector candidates, eight, called Suppressor of early Flg22-induced Immune response (SFI), significantly suppressed flg22-dependent activation of a reporter gene under control of a typical MAMP-inducible promoter (pFRK1-Luc) in tomato protoplasts. We extended our analysis to Arabidopsis thaliana, a non-host plant species of P. infestans. From the aforementioned eight SFI effectors, three appeared to share similar functions in both Arabidopsis and tomato by suppressing transcriptional activation of flg22-induced marker genes downstream of post-translational MAP kinase activation. A further three effectors interfere with MAMP signaling at, or upstream of, the MAP kinase cascade in tomato, but not in Arabidopsis. Transient expression of the SFI effectors in Nicotiana benthamiana enhances susceptibility to P. infestans and, for the most potent effector, SFI1, nuclear localization is required for both suppression of MAMP signaling and virulence function. The present study provides a framework to decipher the molecular mechanisms underlying the manipulation of host MAMP-triggered immunity (MTI) by P. infestans and to understand the basis of host versus non-host resistance in plants towards P. infestans

    Peer-based behavioral health program for drug users in China: a pilot study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Many injection drug users (IDUs) in China have high risk sexual behaviors that contribute to the spread of HIV infection. Although many IDUs in China move through drug rehabilitation centers, this opportunity for sexual health education has largely been overlooked.</p> <p>Methods</p> <p>A convenience sample of 667 drug users from two rehabilitation centers in South China was recruited in the study. Two hundred and forty seven drug users from a single Guangdong Province rehabilitation center received the peer-based education intervention, while 420 drug users from another rehabilitation center received routine HIV/STI education and was used as the control. One hundred and eighty nine (22.1%) individuals refused to participate in the study. HIV/STI behavioral and knowledge domains were assessed at 3 months in rehabilitation centers after the intervention (first follow-up) and at 2-23 months in the community after release (second follow-up).</p> <p>Results</p> <p>Drug users who completed the intervention reported more frequent condom use with casual sex partners (60.0% vs. 12.5% condom use every time, p = 0.011) and less frequent injection (56.7% vs. 26.4% no injection per day, p = 0.008) at the second follow-up compared to those in the routine education group. Loss to follow up was substantial in both control and intervention groups, and was associated with living far from the detention center and having poor HIV knowledge at baseline.</p> <p>Conclusions</p> <p>This study shows that rehabilitation centers may be a useful location for providing behavioral HIV/STI prevention services and referral of individuals to community-based programs upon release. More research is needed on behalf of detained drug users in China who have complex social, medical, and legal needs.</p

    Peer-based behavioral health program for drug users in China: a pilot study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Many injection drug users (IDUs) in China have high risk sexual behaviors that contribute to the spread of HIV infection. Although many IDUs in China move through drug rehabilitation centers, this opportunity for sexual health education has largely been overlooked.</p> <p>Methods</p> <p>A convenience sample of 667 drug users from two rehabilitation centers in South China was recruited in the study. Two hundred and forty seven drug users from a single Guangdong Province rehabilitation center received the peer-based education intervention, while 420 drug users from another rehabilitation center received routine HIV/STI education and was used as the control. One hundred and eighty nine (22.1%) individuals refused to participate in the study. HIV/STI behavioral and knowledge domains were assessed at 3 months in rehabilitation centers after the intervention (first follow-up) and at 2-23 months in the community after release (second follow-up).</p> <p>Results</p> <p>Drug users who completed the intervention reported more frequent condom use with casual sex partners (60.0% vs. 12.5% condom use every time, p = 0.011) and less frequent injection (56.7% vs. 26.4% no injection per day, p = 0.008) at the second follow-up compared to those in the routine education group. Loss to follow up was substantial in both control and intervention groups, and was associated with living far from the detention center and having poor HIV knowledge at baseline.</p> <p>Conclusions</p> <p>This study shows that rehabilitation centers may be a useful location for providing behavioral HIV/STI prevention services and referral of individuals to community-based programs upon release. More research is needed on behalf of detained drug users in China who have complex social, medical, and legal needs.</p

    Chinese Herbal Medicines for the Treatment of Type A H1N1 Influenza: A Systematic Review of Randomized Controlled Trials

    Get PDF
    Chinese herbs are thought to be effective for type A H1N1 influenza. Series of Chinese herbs have been authorized recommended by the Chinese government, and until now a number of clinical trials of Chinese herbs for H1N1 influenza have been conducted. However, there is no critically appraised evidence such as systematic reviews or metaanalyses on potential benefits and harms of medicinal herbs for H1N1 influenza to justify their clinical use and their recommendation. CENTRAL, MEDLINE, EMBASE, CBM, CNKI, VIP, China Important Conference Papers Database, China Dissertation Database, and online clinical trial registry websites were searched for published and unpublished randomized controlled trials (RCTs) of Chinese herbs for H1N1 influenza till 31 August, 2011. A total of 26 RCTs were identified and reviewed. Most of the RCTs were of high risk of bias with flawed study design and poor methodological quality. The combination of several Chinese herbal medicines with or without oseltamivir demonstrated positive effect on fever resolution, relief of symptoms, and global effectiveness rate compared to oseltamivir alone. However, only one herbal medicine showed positive effect on viral shedding. Most of the trials did not report adverse events, and the safety of herbal medicines is still uncertain. Some Chinese herbal medicines demonstrated potential positive effect for 2009 type A H1N1 influenza; however, due to the lack of placebo controlled trial and lack of repeated test of the intervention, we could not draw confirmative conclusions on the beneficial effect of Chinese herbs for H1N1 influenza. More rigorous trials are warranted to support their clinical use

    Herbal Medicines for Parkinson's Disease: A Systematic Review of Randomized Controlled Trials

    Get PDF
    OBJECTIVE: We conducted systematic review to evaluate current evidence of herbal medicines (HMs) for Parkinson's disease (PD). METHODS: Along with hand searches, relevant literatures were located from the electronic databases including CENTRAL, MEDLINE, EMBASE, CINAHL, AMED, PsycInfo, CNKI, 7 Korean Medical Databases and J-East until August, 2010 without language and publication status. Randomized controlled trials (RCTs), quasi-randomized controlled trials and randomized crossover trials, which evaluate HMs for idiopathic PD were selected for this review. Two independent authors extracted data from the relevant literatures and any disagreement was solved by discussion. RESULTS: From the 3432 of relevant literatures, 64 were included. We failed to suggest overall estimates of treatment effects on PD because of the wide heterogeneity of used herbal recipes and study designs in the included studies. When compared with placebo, specific effects were not observed in favor of HMs definitely. Direct comparison with conventional drugs suggested that there was no evidence of better effect for HMs. Many studies compared combination therapy with single active drugs and combination therapy showed significant improvement in PD related outcomes and decrease in the dose of anti-Parkinson's drugs with low adverse events rate. CONCLUSION: Currently, there is no conclusive evidence about the effectiveness and efficacy of HMs on PD. For establishing clinical evidence of HMs on PD, rigorous RCTs with sufficient statistical power should be promoted in future

    Functional Analysis of the Kinome of the Wheat Scab Fungus Fusarium graminearum

    Get PDF
    As in other eukaryotes, protein kinases play major regulatory roles in filamentous fungi. Although the genomes of many plant pathogenic fungi have been sequenced, systematic characterization of their kinomes has not been reported. The wheat scab fungus Fusarium graminearum has 116 protein kinases (PK) genes. Although twenty of them appeared to be essential, we generated deletion mutants for the other 96 PK genes, including 12 orthologs of essential genes in yeast. All of the PK mutants were assayed for changes in 17 phenotypes, including growth, conidiation, pathogenesis, stress responses, and sexual reproduction. Overall, deletion of 64 PK genes resulted in at least one of the phenotypes examined, including three mutants blocked in conidiation and five mutants with increased tolerance to hyperosmotic stress. In total, 42 PK mutants were significantly reduced in virulence or non-pathogenic, including mutants deleted of key components of the cAMP signaling and three MAPK pathways. A number of these PK genes, including Fg03146 and Fg04770 that are unique to filamentous fungi, are dispensable for hyphal growth and likely encode novel fungal virulence factors. Ascospores play a critical role in the initiation of wheat scab. Twenty-six PK mutants were blocked in perithecia formation or aborted in ascosporogenesis. Additional 19 mutants were defective in ascospore release or morphology. Interestingly, F. graminearum contains two aurora kinase genes with distinct functions, which has not been reported in fungi. In addition, we used the interlog approach to predict the PK-PK and PK-protein interaction networks of F. graminearum. Several predicted interactions were verified with yeast two-hybrid or co-immunoprecipitation assays. To our knowledge, this is the first functional characterization of the kinome in plant pathogenic fungi. Protein kinase genes important for various aspects of growth, developmental, and infection processes in F. graminearum were identified in this study

    金属氧化物纳米材料的设计与合成策略

    Full text link
    corecore