48 research outputs found

    DFIG machine design for maximizing power output based on surrogate optimization algorithm

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    This paper presents a surrogate-model-based optimization of a doubly-fed induction generator (DFIG) machine winding design for maximizing power yield. Based on site-specific wind profile data and the machine's previous operational performance, the DFIG's stator and rotor windings are optimized to match the maximum efficiency with operating conditions for rewinding purposes. The particle swarm optimization-based surrogate optimization techniques are used in conjunction with the finite element method to optimize the machine design utilizing the limited available information for the site-specific wind profile and generator operating conditions. A response surface method in the surrogate model is developed to formulate the design objectives and constraints. Besides, the machine tests and efficiency calculations follow IEEE standard 112-B. Numerical and experimental results validate the effectiveness of the proposed technologies

    Obfuscated Android Application Development

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    International audienceObfuscation techniques help developers to hide their code when distributing an Android application. The used techniques are linked to the features provided by the programming language but also with the way the application is executed. Using obfuscation is now a common practice and specialized companies sell tools or services for automatizing the manipulation of the source code. In this paper, we present how to develop obfuscated applications and how obfuscation technique usage is evolving in the wild. First, using advanced obfuscation techniques requires some advanced knowledge about the development of Android applications. We describe how to build such applications for helping researchers to generate samples of obfuscated applications for their own research. Second, the use of obfuscation techniques is evolving for both regular applications or malicious ones. We aim at measuring the development of these usages by studying application and malware samples and the artifacts that indicate the use of obfuscation techniques

    Chinese medicines as a resource for liver fibrosis treatment

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    Liver fibrosis is a condition of abnormal proliferation of connective tissue due to various types of chronic liver injury often caused by viral infection and chemicals. Effective therapies against liver fibrosis are still limited. In this review, we focus on research on Chinese medicines against liver fibrosis in three categories, namely pure compounds, composite formulae and combination treatment using single compounds with composite formulae or conventional medicines. Action mechanisms of the anti-fibrosis Chinese medicines, clinical application, herbal adverse events and quality control are also reviewed. Evidence indicates that some Chinese medicines are clinically effective on liver fibrosis. Strict quality control such as research to identify and monitor the manufacturing of Chinese medicines enables reliable pharmacological, clinical and in-depth mechanism studies. Further experiments and clinical trials should be carried out on the platforms that conform to international standards

    Effectiveness of Chinese herbal medicine in treating liver fibrosis: a systematic review and meta-analysis of randomized controlled trials

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    <p>Abstract</p> <p>Background</p> <p>The studies on the effectiveness of Chinese herbal medicines (CHM) in treating liver fibrosis (LF) were not consistent. This study aims to systematically review the effectiveness of CHM on treating LF patients.</p> <p>Methods</p> <p>Databases including MEDLINE, AMED, EMBASE, The Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, TCMOnline, Chinese Biomedical Literature Database, and Chinese Medical Current Contents were searched up to March 2011. Randomized controlled trials (RCTs) involving LF patients receiving CHM, Western medicine, combined CHM and Western medicine compared with placebo, Western medicine or no intervention were included. LF markers including serum hyaluronic acid (HA), laminin (LN), procollagen type III (PC-III), type IV collagen (IV-C), matrix metalloproteinase (MMP), and tissue inhibitors of metalloproteinase (TIMP) were measured as primary outcomes. Liver biochemistry, including alanine aminotransferase (ALT) and aspartarte aminotransferase (AST), and improvement of related clinical symptoms were measured as secondary outcomes. Risk of bias of allocation sequence, allocation concealment, blinding, incomplete outcome data, selective outcome reporting, and other biases were assessed.</p> <p>Results</p> <p>Twenty-three RCTs with 2123 participants were analyzed in subgroups of types of comparison and study quality. Fifteen studies were graded as good quality. CHM alone and combined with Western medicine showed significant improvements in HA, LN, PC-III and IV-C compared with Western medicine alone. However, there were no significant differences observed between CHM and placebo treatments.</p> <p>Conclusion</p> <p>The current inconclusive results in determining the effectiveness of CHM treatment on LF, due to the poor methodological quality and high heterogeneity of the studies, suggests that large RCTs using standardized Chinese medicine syndrome diagnosis and CHM formulae with longer follow-up are required for further evaluation.</p

    Hepatoprotective effects of berberine on carbon tetrachloride-induced acute hepatotoxicity in rats

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    Background: Berberine is an active compound in Coptidis Rhizoma (Huanglian) with multiple pharmacological activities including antimicrobial, antiviral, anti-inflammatory, cholesterol-lowering and anticancer effects. The present study aims to determine the hepatoprotective effects of berberine on serum and tissue superoxide dismutase (SOD) levels, the histology in tetrachloride (CCl 4)-induced liver injury.Methods: Sprague-Dawley rats aged seven weeks were injected intraperitoneally with 50% CCl 4 in olive oil. Berberine was orally administered before or after CCl 4 treatment in various groups. Twenty-four hours after CCl 4 injection, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, serum and liver superoxide dismutase (SOD) activities were measured. Histological changes of liver were examined with microscopy.Results: Serum ALT and AST activities significantly decreased in a dose-dependent manner in both pre-treatment and post-treatment groups with berberine. Berberine increased the SOD activity in liver. Histological examination showed lowered liver damage in berberine-treated groups.Conclusion: The present study demonstrates that berberine possesses hepatoprotective effects against CCl 4-induced hepatotoxicity and that the effects are both preventive and curative. Berberine should have potential for developing a new drug to treat liver toxicity. © 2010 Feng et al; licensee BioMed Central Ltd.published_or_final_versio

    Advances of the small molecule drugs regulating fibroblast-like synovial proliferation for rheumatoid arthritis

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    Rheumatoid arthritis (RA) is a type of chronic autoimmune and inflammatory disease. In the pathological process of RA, the alteration of fibroblast-like synoviocyte (FLS) and its related factors is the main influence in the clinic and fundamental research. In RA, FLS exhibits a uniquely aggressive phenotype, leading to synovial hyperplasia, destruction of the cartilage and bone, and a pro-inflammatory environment in the synovial tissue for perpetuation and progression. Evidently, it is a highly promising way to target the pathological function of FLS for new anti-RA drugs. Based on this, we summed up the pathological mechanism of RA-FLS and reviewed the recent progress of small molecule drugs, including the synthetic small molecule compounds and natural products targeting RA-FLS. In the end, there were some views for further action. Compared with MAPK and NF-κB signaling pathways, the JAK/STAT signaling pathway has great potential for research as targets. A small number of synthetic small molecule compounds have entered the clinic to treat RA and are often used in combination with other drugs. Meanwhile, most natural products are currently in the experimental stage, not the clinical trial stage, such as triptolide. There is an urgent need to unremittingly develop new agents for RA

    Aboveground herbivory does not affect mycorrhiza-dependent nitrogen acquisition from soil but inhibits mycorrhizal network-mediated nitrogen interplant transfer in maize

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    Arbuscular mycorrhizal fungi (AMF) are considered biofertilizers for sustainable agriculture due to their ability to facilitate plant uptake of important mineral elements, such as nitrogen (N). However, plant mycorrhiza-dependent N uptake and interplant transfer may be highly context-dependent, and whether it is affected by aboveground herbivory remains largely unknown. Here, we used 15N labeling and tracking to examine the effect of aboveground insect herbivory by Spodoptera frugiperda on mycorrhiza-dependent N uptake in maize (Zea mays L.). To minimize consumption differences and 15N loss due to insect chewing, insect herbivory was simulated by mechanical wounding and oral secretion of S. frugiperda larvae. Inoculation with Rhizophagus irregularis (Rir) significantly improved maize growth, and N/P uptake. The 15N labeling experiment showed that maize plants absorbed N from soils via the extraradical mycelium of mycorrhizal fungi and from neighboring plants transferred by common mycorrhizal networks (CMNs). Simulated aboveground leaf herbivory did not affect mycorrhiza-mediated N acquisition from soil. However, CMN-mediated N transfer from neighboring plants was blocked by leaf simulated herbivory. Our findings suggest that aboveground herbivory inhibits CMN-mediated N transfer between plants but does not affect N acquisition from soil solutions via extraradical mycorrhizal mycelium

    Bear bile: dilemma of traditional medicinal use and animal protection

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    Bear bile has been used in Traditional Chinese Medicine (TCM) for thousands of years. Modern investigations showed that it has a wide range of pharmacological actions with little toxicological side effect and the pure compounds have been used for curing hepatic and biliary disorders for decades. However, extensive consumption of bear bile made bears endangered species. In the 1980's, bear farming was established in China to extract bear bile from living bears with "Free-dripping Fistula Technique". Bear farming is extremely inhumane and many bears died of illness such as chronic infections and liver cancer. Efforts are now given by non-governmental organizations, mass media and Chinese government to end bear farming ultimately. At the same time, systematic research has to be done to find an alternative for bear bile. In this review, we focused on the literature, laboratory and clinical results related to bear bile and its substitutes or alternative in English and Chinese databases. We examined the substitutes or alternative of bear bile from three aspects: pure compounds derived from bear bile, biles from other animals and herbs from TCM. We then discussed the strategy for stopping the trading of bear bile and issues of bear bile related to potential alternative candidates, existing problems in alternative research and work to be done in the future

    What Determines BIM Competition Results of Undergraduate Students in the Architecture, Engineering and Construction Industry?

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    Building Information Modeling (BIM) has become the development trend in the architecture, engineering, and construction (AEC) industry. BIM discipline competition is an effective way for students of AEC-related disciplines to integrate theory with practice, and it is a key link to cultivate qualified BIM practitioners. This study takes participants of the 8th National College BIM Graduation Design Innovation Competition as the research objects. The Technology Acceptance Model and the Theory of Planned Behavior are combined to build a driving factor model of the competitions. Contestants of the competition were asked to complete online questionnaires, and 451 valid samples were finally obtained. Structural Equation Modeling was used to fit the theoretical model, and it was found that: Behavioral Intention to use BIM is directly and positively affected by Attitude, Perceived Behavioral Control, and Perceived Usefulness, as well as indirectly and positively affected by Perceived Usefulness and Perceived Eased of Usefulness. Competition Results is directly and positively affected by Behavioral Intention to use BIM, Perceived Behavioral Control, and Facilitating Conditions. It is also indirectly and positively affected by Attitude, Perceived Behavior Control, Perceived Usefulness, and Perceived Eased of Usefulness. The results show that the situation of students&rsquo; participation in BIM competition can be optimized by increasing the publicity and promotion of BIM and related policies, strengthening the construction of supporting teaching facilities, building the integrated curriculum system of BIM technology, and strengthening teacher training. This study provides a theoretical reference for further BIM practice, and it would help improve the corresponding teaching organization and enhance the internal drive of students&rsquo; BIM learning

    Cumulative evidence for relationships between multiple variants of HNF1B and the risk of prostate and endometrial cancers

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    Abstract Background To provide a synopsis of the current understanding of the association between variants of HNF1B and cancer susceptibility, we conducted a comprehensive research synopsis and meta-analysis to evaluate associations between HNF1B variants and prostate and endometrial cancers. Results Eighteen studies totaling 34,937 patients and 55,969 controls were eligible for this meta-analysis. Four variants showed a significant association with the risk of individual cancer. Strong significant associations were found between rs4430796 A and the risk of both prostate cancer (OR = 1.247, p = 2.21 × 10− 77) and endometrial cancer (OR = 1.217, p = 8.98 × 10− 16); the AA, AG genotypes also showed strong significant associations with the risk of prostate cancer (OR1 = 1.517, p = 4.46 × 10− 22; OR2 = 1.180, p = 0.002). There was a strong significant association between rs7501939 G and the risk of prostate cancer (OR = 1.201, p = 9.31 × 10− 31). Strong significant association was found between rs11649743 G (OR = 1.138, p = 1.08 × 10− 12), rs3760511 C (OR = 1.214, p = 1.57 × 10− 19) and the prostate cancer risk;the GG, AG genotypes of rs11649743 also showed strong significant associations with the risk of prostate cancer (OR1 = 1.496, p = 3.32 × 10− 6; OR2 = 1.276, p = 7.82 × 10− 6). All the cumulative epidemiological evidence of associations was graded as strong. Conclusions Our study summarizes the evidence and helps to reveal that common variants of HNF1B are associated with risk of prostate and endometrial cancer
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