6,264 research outputs found

    Electromagnetic detection of axions

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    Photon-to-axion conversions in the static electromagnetic fields are reconsidered in detail by using the Feynman diagram techniques. The differential cross sections are presented for the conversions in the presence of the electric field of the flat condenser as well as in the magnetic field of the solenoid. Based on our results a laboratory experiment for the production and the detection of the axions is described. This experiment will exploit the axion decay constant as well as the axion mass.Comment: 7 pages, latex, no figures, to appear in Phys. Lett.

    Toward a Standardized Strategy of Clinical Metabolomics for the Advancement of Precision Medicine

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    Despite the tremendous success, pitfalls have been observed in every step of a clinical metabolomics workflow, which impedes the internal validity of the study. Furthermore, the demand for logistics, instrumentations, and computational resources for metabolic phenotyping studies has far exceeded our expectations. In this conceptual review, we will cover inclusive barriers of a metabolomics-based clinical study and suggest potential solutions in the hope of enhancing study robustness, usability, and transferability. The importance of quality assurance and quality control procedures is discussed, followed by a practical rule containing five phases, including two additional "pre-pre-" and "post-post-" analytical steps. Besides, we will elucidate the potential involvement of machine learning and demonstrate that the need for automated data mining algorithms to improve the quality of future research is undeniable. Consequently, we propose a comprehensive metabolomics framework, along with an appropriate checklist refined from current guidelines and our previously published assessment, in the attempt to accurately translate achievements in metabolomics into clinical and epidemiological research. Furthermore, the integration of multifaceted multi-omics approaches with metabolomics as the pillar member is in urgent need. When combining with other social or nutritional factors, we can gather complete omics profiles for a particular disease. Our discussion reflects the current obstacles and potential solutions toward the progressing trend of utilizing metabolomics in clinical research to create the next-generation healthcare system.11Ysciescopu

    An investigation of the evidence of benefits from climate compatible development

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    Climate change is likely to have profound effects on developing countries both through the climate impacts experienced, but also through the policies, programmes and projects adopted to address climate change. Climate change mitigation (actions taken to reduce the extent of climate change), adaptation (actions taken to ameliorate the impacts), and on-going development are all critical to reduce current and future losses associated with climate change, and to harness gains. In the context of limited resources to invest in climate change, policies, programmes, or projects that deliver ‘triple wins’ (i.e. generating climate adaptation, mitigation and development benefits) – also known as climate compatible development – are increasingly discussed by bilateral and multilateral donors. Yet there remains an absence of empirical evidence of the benefits and costs of triple win policies. The purpose of this paper is therefore to assess evidence of ‘triple wins’ on the ground, and the feasibility of triple wins that do not generate negative impacts. We describe the theoretical linkages that exist between adaptation, mitigation and development, as well as the trade-offs and synergies that might exist between them. Using four developing country studies, we make a simple assessment of the extent of climate compatible development policy in practice through the lens of ‘no-regrets’, ‘low regrets’ and ‘with regrets’ decision making. The lack of evidence of either policy or practice of triple wins significantly limits the capacity of donors to identify, monitor or evaluate ‘triple wins at this point in time. We recommend a more strategic assessment of the distributional and financial implications of 'triple wins' policies

    TETRAOXYGENATED XANTHONES FROM THE LATEX OF GARCINIA COWA

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    Seven tetraoxygenated xanthones, namely fuscaxanthone A,7-O-methylgarcinone E, cowagarcinone A, cowaxanthone, rubraxanthone, cowanin and cowanol, were isolated from the dichloromethane extract of the latex of Garcinia cowa_Roxb. ex Choisy. Their structures were elucidated on the basis of 1D, 2D NMR spectroscopic data and comparison with reported data

    Mediating effect of firm efficiency on the controlling shareholdings–firm performance nexus: Evidence from public listed firms in Malaysia

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    This study examines how controlling shareholders influence firm performance through the mediating role of firm efficiency in transforming inputs into outputs. To achieve this objective, it conducts a mediation analysis with 5,000 bootstraps on a dataset of 2,849 firm-year observations of publicly listed firms in Malaysia from 2009 to 2019. The findings reveal a positive relationship between controlling shareholdings and firm performance, with both total and indirect effects having this positive relationship. Moreover, while controlling shareholdings improve firm performance, firm efficiency partially mediates this relationship. Thus, improved firm efficiency plays a critical role in understanding the relationship between governance by controlling shareholders and enhanced firm performance. In summary, this study contributes to the existing literature by expanding our understanding of the complex relationship between controlling shareholdings, firm efficiency, and firm performance. In addition, the findings shed light on the importance of indirect channels in shaping organizational outcomes. As such, this study provides a valuable direction for future research in this area

    FLAVONOIDS AND TRITERPENOIDS FROM CALLISTEMON CITRINUS AND THEIR INHIBITORY EFFECT ON NO PRODUCTION IN LPS-STIMULATED RAW264.7 MACROPHAGES

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    Phytochemical investigation of the leaves and stems of Callistemon citrinus (Curtis) Skeels led to the isolation of 12 flavonoid and triterpenoid compounds,  including one new flavonoid, callistine A (1) and six known flavonoids 6,7- dimethyl-5,7-dihydroxy-4’-methoxy flavone (2), astragalin (3), quercetin (4), catechin (5), eucalyptin (6), and 8-demethyleucalyptin (7), along with 5 triterpenoids, 3-β-acetylmorolic acid (8), 3β-hydroxy-urs-11-en-13(28)-olide (9), betulinic acid (10), diospyrolide (11) and ursolic acid (12). Their chemical structures were determined from the spectroscopic evidences counting 1D- and 2D-NMR and HR-MS data. All the isolated compounds were examined for their anti-inflammatory activity against LPS-activated NO production in macrophage RAW264.7 cells. Among them, quercetin (4) and 3β-hydroxy-urs-11-en-13(28)-olide (9) showed potential inhibition activity in nitric oxide (NO)  production in RAW264.7 cells exposed to LPS

    Buckling and vibration analysis of laminated composite plate/shell structures via a smoothed quadrilateral flat shell element with in-plane rotations

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    This paper presents buckling and free vibration analysis of composite plate/shell structures of various shapes, modulus ratios, span-to-thickness ratios, boundary conditions and lay-up sequences via a novel smoothed quadrilateral flat element. The element is developed by incorporating a strain smoothing technique into a flat shell approach. As a result, the evaluation of membrane, bending and geometric stiffness matrices are based on integration along the boundary of smoothing elements, which leads to accurate numerical solutions even with badly-shaped elements. Numerical examples and comparison with other existing solutions show that the present element is efficient, accurate and free of locking

    Risk Factors for Human Infection with Avian Influenza A H5N1, Vietnam, 2004

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    TOC Summary: Risk factors include direct or household contact with sick or dead poultry and absence of an indoor water source
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