hot spots

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  • 文章类型: Journal Article
    Surface Enhanced Raman Scattering (SERS) is a field of research that has shown promising application in the analysis of various substrate molecules by means of rough metallic surfaces. In directing the enhancement of substrate molecules in micro and nano-molar concentrations, plasmonic coupling of metal nanoparticles (NPs), morphology of metal NPs and the closely arrangement of rough metal surfaces that produces \'hot spots\' can effectively increase the so-called enhancement factor (EF) that will be applicable in various fields. As the mechanistic aspects are still not clear, research has been triggered all over the world for the past two decades to have a clear understanding in chemical and electromagnetic effects. As the reproducibility of intensity of signals at low concentrations of probe molecules is of a big concern, metal NPs with various scaffolds were prepared and recently bio-molecule, DNA has been studied and showed promising advantages. This review first time highlights metal NPs with DNA interface as an effective rough metallic surface for SERS with high intensity and also with better reproducibility. Based on this review, similar kinds of scaffolds like DNA can be used to further analyze SERS activities of various metal NPs with different morphologies to have high intense signals at low concentrations of probe molecules.
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  • 文章类型: Journal Article
    The Earth is experiencing excessive nitrogen (N) input to its various ecosystems due to human activities. How to effectively and efficiently remove N from ecosystems has been, is and will be at the center of attention in N research. Hyporheic and riparian zones are widely acknowledged for their buffering capacity to reduce contaminants (especially N) transport downstream. However, these zones are usually misunderstood that they can remove N at all spots and at any moments. Here pathways of N removal from hyporheic and riparian zones are reviewed and summarized with an emphasize on their hot spots and hot moments. N is biogeochemically removed by denitrification, anammox, nitrifier denitrification, denitrifying anaerobic methane oxidation, Feammox and Sulfammox. Hot moments of N removal are mainly triggered by precipitation, fire and snowmelt. Finally, some research needs are outlined and discussed, such as developing approaches for multiscale sampling and monitoring, quantifying the effects of hot spots and hot moments at hyporheic and riparian zones and evaluating the impacts of human activities on hot spots and hot moments, to inspire more research on hot spots and hot moments of N removal. By this review, we hope to bring awareness of the heterogeneity of hyporheic and riparian zones to catchment managers and policy makers when tackling N pollution problems.
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  • 文章类型: Journal Article
    Terrestrial inputs into freshwater ecosystems are a classical field of environmental science. Resource fluxes (subsidy) from aquatic to terrestrial systems have been less studied, although they are of high ecological relevance particularly for the receiving ecosystem. These fluxes may, however, be impacted by anthropogenically driven alterations modifying structure and functioning of aquatic ecosystems. In this context, we reviewed the peer-reviewed literature for studies addressing the subsidy of terrestrial by aquatic ecosystems with special emphasis on the role that anthropogenic alterations play in this water-land coupling. Our analysis revealed a continuously increasing interest in the coupling of aquatic to terrestrial ecosystems between 1990 and 2014 (total: 661 studies), while the research domains focusing on abiotic (502 studies) and biotic (159 studies) processes are strongly separated. Approximately 35% (abiotic) and 25% (biotic) of the studies focused on the propagation of anthropogenic alterations from the aquatic to the terrestrial system. Among these studies, hydromorphological and hydrological alterations were predominantly assessed, whereas water pollution and invasive species were less frequently investigated. Less than 5% of these studies considered indirect effects in the terrestrial system e.g. via food web responses, as a result of anthropogenic alterations in aquatic ecosystems. Nonetheless, these very few publications indicate far-reaching consequences in the receiving terrestrial ecosystem. For example, bottom-up mediated responses via soil quality can cascade over plant communities up to the level of herbivorous arthropods, while top-down mediated responses via predatory spiders can cascade down to herbivorous arthropods and even plants. Overall, the current state of knowledge calls for an integrated assessment on how these interactions within terrestrial ecosystems are affected by propagation of aquatic ecosystem alterations. To fill these gaps, we propose a scientific framework, which considers abiotic and biotic aspects based on an interdisciplinary approach.
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  • 文章类型: Journal Article
    本文批判性地分析了九项关于创伤分娩后产后创伤后应激障碍(PTSD)的研究,为了找到创伤后应激障碍症状的共同主题,以PTSD的认知模型为指导;它对其中一项研究进行了深入的批判性评估,并试图解释创伤性分娩后患有产后PTSD的妇女的生活经历以及认知行为疗法(CBT)对产后PTSD的适用性。本文发现,创伤性分娩后的妇女确实会经历产后PTSD;产后PTSD症状与其他事件的PTSD症状相似,其他事件的PTSDCBT对产后PTSD同样有效。未来的建议包括更多的定性研究和解释现象学方法,以便为该客户群体建立基于证据的CBT治疗。和更多的转诊需要发送到心理服务CBT干预。
    This paper critically analyses nine studies on postnatal posttraumatic stress disorder (PTSD) following traumatic childbirth, in order to find common themes of PTSD symptoms, using the cognitive model of PTSD as a guide; it critically appraised one of the studies in depth and it attempted to explain the lived experience of women suffering from postnatal PTSD following traumatic childbirth and the suitability of cognitive behavioural therapy (CBT) for postnatal PTSD. This paper found that women following traumatic childbirth do experience postnatal PTSD; postnatal PTSD symptoms are similar to PTSD symptoms of other events and that CBT for PTSD of other events is just as effective for postnatal PTSD. Future recommendations include more qualitative studies with interpretative phenomenological approach in order to establish evidence-based CBT treatment for this client group, and more referrals need to be sent to the psychological services for CBT intervention.
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