5,278 research outputs found

    Regional Distribution and Human Health Effects of Persistent Organic Pollutants (POPs) in Zhejiang Province

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    Zhejiang (ZJ) is a developed province located in the southeast coast of China. In recent years, growing concern has been aroused over the persistent organic pollutants (POPs) pollution associated with electronic and electric waste (e-waste) in this province. This chapter has provided numerous and integrated information concerning POPs pollution level and human health effects in ZJ. The residue levels of major POPs, including DDT, PCDD/Fs, PCBs and PCP/PCP-Na, in the environmental media, local food and human body were relatively higher in polluted areas of intensive e-waste dismantling industry compared with control areas. POPs pollution levels and cancer incidence in both polluted areas and control areas were comparable with the national data. In vitro test and population survey provided evidence that PCBs exposure altered the expression of genes involved in nervous system- and immune system-related diseases, and the CCL22 gene could serve as an effective biomarker for PCBs exposure. Additionally, e-waste management in ZJ province was discussed. Taken together, these data suggest that POPs pollution in ZJ may be correlated to local e-waste recycling activities. In the future, more efforts should be devoted to improve the techniques for e-waste recycling and establish a sound e-waste management framework

    Theoretical and numerical modeling of Rayleigh wave scattering by an elastic inclusion

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    This work presents theoretical and numerical models for the backscattering of two-dimensional Rayleigh waves by an elastic inclusion, with the host material being isotropic and the inclusion having arbitrary shape and crystallographic symmetry. The theoretical model is developed based on the reciprocity theorem using the far-field Green's function and the Born approximation, assuming a small acoustic impedance difference between the host and inclusion materials. The numerical finite element (FE) model is established to deliver relatively accurate simulation of the scattering problem and to evaluate the approximations of the theoretical model. Quantitative agreement is observed between the theoretical model and the FE results for arbitrarily-shaped surface/subsurface inclusions with isotropic/anisotropic properties. The agreement is excellent when the wavelength of the Rayleigh wave is larger than, or comparable to, the size of the inclusion, but it deteriorates as the wavelength gets smaller. Also, the agreement decreases with the anisotropy index for inclusions of anisotropic symmetry. The results lay the foundation for using Rayleigh waves for quantitative characterization of surface/subsurface inclusions, while also demonstrating its limitations.Comment: 25 pages, 8 figures. The article has been submitted to The Journal of the Acoustical Society of America. After it is published, it will be found at https://asa.scitation.org/journal/ja

    The Current Status and Future Prospects for Conversion Therapy in the Treatment of Hepatocellular Carcinoma

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    Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related deaths worldwide. In China, most HCC patients are diagnosed with advanced disease and in these cases surgery is challenging. Conversion therapy can be used to change unresectable HCC into resectable disease and is a potential breakthrough treatment strategy. The resection rate for unresectable advanced HCC has recently improved as a growing number of patients have benefited from conversion therapy. While conversion therapy is at an early stage of development, progress in patient selection, optimum treatment methods, and the timing of surgery have the potential to deliver significant benefits. In this article, we review the current evidence and clinical experience of conversion therapy in HCC. General conversion modalities such as systemic treatments (systemic chemotherapy, targeted therapy, or immunotherapy), locoregional therapy (transarterial chemoembolization, hepatic arterial infusion chemotherapy, or selective internal radiation therapy), and combination therapy were summarized. We also discuss the current challenges of conversion therapy and provide identify areas for future research to improve the development of conversion therapy in advanced HCC

    APIS: accurate prediction of hot spots in protein interfaces by combining protrusion index with solvent accessibility

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    <p>Abstract</p> <p>Background</p> <p>It is well known that most of the binding free energy of protein interaction is contributed by a few key hot spot residues. These residues are crucial for understanding the function of proteins and studying their interactions. Experimental hot spots detection methods such as alanine scanning mutagenesis are not applicable on a large scale since they are time consuming and expensive. Therefore, reliable and efficient computational methods for identifying hot spots are greatly desired and urgently required.</p> <p>Results</p> <p>In this work, we introduce an efficient approach that uses support vector machine (SVM) to predict hot spot residues in protein interfaces. We systematically investigate a wide variety of 62 features from a combination of protein sequence and structure information. Then, to remove redundant and irrelevant features and improve the prediction performance, feature selection is employed using the F-score method. Based on the selected features, nine individual-feature based predictors are developed to identify hot spots using SVMs. Furthermore, a new ensemble classifier, namely APIS (A combined model based on Protrusion Index and Solvent accessibility), is developed to further improve the prediction accuracy. The results on two benchmark datasets, ASEdb and BID, show that this proposed method yields significantly better prediction accuracy than those previously published in the literature. In addition, we also demonstrate the predictive power of our proposed method by modelling two protein complexes: the calmodulin/myosin light chain kinase complex and the heat shock locus gene products U and V complex, which indicate that our method can identify more hot spots in these two complexes compared with other state-of-the-art methods.</p> <p>Conclusion</p> <p>We have developed an accurate prediction model for hot spot residues, given the structure of a protein complex. A major contribution of this study is to propose several new features based on the protrusion index of amino acid residues, which has been shown to significantly improve the prediction performance of hot spots. Moreover, we identify a compact and useful feature subset that has an important implication for identifying hot spot residues. Our results indicate that these features are more effective than the conventional evolutionary conservation, pairwise residue potentials and other traditional features considered previously, and that the combination of our and traditional features may support the creation of a discriminative feature set for efficient prediction of hot spot residues. The data and source code are available on web site <url>http://home.ustc.edu.cn/~jfxia/hotspot.html</url>.</p

    Multi-compartment centrifugal electrospinning based composite fibers

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    Multi-faceted technological advances in fiber science have proven to be invaluable in several emerging biomaterial and biomedical engineering applications. In the last decade, notable fiber engineering advances have been demonstrated ranging from co-axial flows (for micron and nano-scaled layering), non-concentric flows (for Janus composites) and even 3D printing (for controlled alignment). The ES process is however limited, both for commercial impact (low production rates) and also in its facile capability to deliver reliable mimicry of numerous biological tissues which comprise blended and aligned fibers (e.g. tendons and ligaments). In the technological advance demonstrated here, a combinatorial multi-compartment centrifugal electrospinning (CMCCE) system is developed and demonstrated. A proof-of-concept enabling multiple formulation solution hosting (including combinatorial grading) in a single centrifugal electrospinning system (CES) comprising one spinneret is shown. Using this process, controlled blending and tuning of resulting fibrous membrane properties (contact angle and active release behavior) via aligned and phased fiber mat composition is demonstrated. In addition, the CMCCE process is capable of replicating production rates of recently developed centrifugal electrospinning systems (∼120 g/h), while potentially permitting better mimicry of naturally occurring fibrous tissue blends. It is envisaged the advance in technology will be ideally suited to engineer synthetic fibrous biomaterials with greater host surface replication and will fulfil production rate requirements for the industrial sector

    GROUND REACTION FORCE ANALYSIS OF SOFTBALL WINDMILL PITCH

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    INTRODUCTION: The lower extremity provides supports when we exercise. The roles what lower extremity plays should be clarified during pitching. Therefore, the purpose of the current study was to observe the ground reaction force during a windmill pitcher pitching straight ball and rise ball
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