469 research outputs found

    A novel design of a hybrid glulam-steel substructure for the IEA 15-MW floating wind turbine

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    Wind energy has become increasingly recognised as a very promising type of renewable energy. In addition, floating offshore wind turbines have facilitated the development of electricity production in intermediate (45-150 m) and deep sea (>150 m) depths. Despite this, wind turbine manufacturing, installation, and operation may generate substantial greenhouse gas emissions. A novel hybrid glulam-steel floating substructure design is presented in this research, intended for the IEA 15 MW floating wind turbine. The objective is to contribute to advancing floating wind energy while minimising costs and carbon dioxide emissions. The objective of the novel design is to substitute steel with glued laminated lumber (glulam). It showcases an altered iteration of the UMaine VolturnUS-S semi-submersible platform originally created for the IEA 15 MW turbine. Before selecting one of three preliminary hybrid wood-steel models, the Ansys Workbench 2020 R1 is used to evaluate and appraise them per a set of criteria extracted from pertinent timber and steel standards. The chosen hybrid design conserves about 590 metric tonnes of steel mass compared to the UMaine VolturnUS-S semi-submersible platform. The selected model is then validated by executing a fully coupled aero-hydro-servo-elastic dynamic analysis with OpenFAST. Consideration is limited to the ultimate limit state design (ULS) for normal and severe operating situations. The utilisation factor of the glulam supporting structure for the IEA 15 MW turbine ranges from 74% to 94%, indicating that it is an effective load-bearing solution.publishedVersio

    Nitric Oxide: Physiological Functions, Delivery, and Biomedical Applications

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    Nitric oxide (NO) is a gaseous molecule that has a central role in signaling pathways involved in numerous physiological processes (e.g., vasodilation, neurotransmission, inflammation, apoptosis, and tumor growth). Due to its gaseous form, NO has a short half-life, and its physiology role is concentration dependent, often restricting its function to a target site. Providing NO from an external source is beneficial in promoting cellular functions and treatment of different pathological conditions. Hence, the multifaceted role of NO in physiology and pathology has garnered massive interest in developing strategies to deliver exogenous NO for the treatment of various regenerative and biomedical complexities. NO-releasing platforms or donors capable of delivering NO in a controlled and sustained manner to target tissues or organs have advanced in the past few decades. This review article discusses in detail the generation of NO via the enzymatic functions of NO synthase as well as from NO donors and the multiple biological and pathological processes that NO modulates. The methods for incorporating of NO donors into diverse biomaterials including physical, chemical, or supramolecular techniques are summarized. Then, these NO-releasing platforms are highlighted in terms of advancing treatment strategies for various medical problems

    Addressing the batch effect issue for LC/MS metabolomics data in data preprocessing.

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    With the growth of metabolomics research, more and more studies are conducted on large numbers of samples. Due to technical limitations of the Liquid Chromatography-Mass Spectrometry (LC/MS) platform, samples often need to be processed in multiple batches. Across different batches, we often observe differences in data characteristics. In this work, we specifically focus on data generated in multiple batches on the same LC/MS machinery. Traditional preprocessing methods treat all samples as a single group. Such practice can result in errors in the alignment of peaks, which cannot be corrected by post hoc application of batch effect correction methods. In this work, we developed a new approach that address the batch effect issue in the preprocessing stage, resulting in better peak detection, alignment and quantification. It can be combined with down-stream batch effect correction methods to further correct for between-batch intensity differences. The method is implemented in the existing workflow of the apLCMS platform. Analyzing data with multiple batches, both generated from standardized quality control (QC) plasma samples and from real biological studies, the new method resulted in feature tables with better consistency, as well as better down-stream analysis results. The method can be a useful addition to the tools available for large studies involving multiple batches. The method is available as part of the apLCMS package. Download link and instructions are at https://mypage.cuhk.edu.cn/academics/yutianwei/apLCMS/

    Stress related epigenetic changes may explain opportunistic success in biological invasions in Antipode mussels

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    Different environmental factors could induce epigenetic changes, which are likely involved in the biological invasion process. Some of these factors are driven by humans as, for example, the pollution and deliberate or accidental introductions and others are due to natural conditions such as salinity. In this study, we have analysed the relationship between different stress factors: time in the new location, pollution and salinity with the methylation changes that could be involved in the invasive species tolerance to new environments. For this purpose, we have analysed two different mussels’ species, reciprocally introduced in antipode areas: the Mediterranean blue mussel Mytilus galloprovincialis and the New Zealand pygmy mussel Xenostrobus securis, widely recognized invaders outside their native distribution ranges. The demetylathion was higher in more stressed population, supporting the idea of epigenetic is involved in plasticity process. These results can open a new management protocols, using the epigenetic signals as potential pollution monitoring tool. We could use these epigenetic marks to recognise the invasive status in a population and determine potential biopollutants

    Pore engineering of ultrathin covalent organic framework membranes for organic solvent nanofiltration and molecular sieving

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    The advantages of two dimensional covalent organic framework membranes to achieve high flux have been demonstrated, but the capability of easy structural modification to manipulate the pore size has not been fully explored yet. Here we report the use of the Langmuir–Blodgett method to synthesize two ultrathin covalent organic framework membranes (TFP–DPF and TFP–DNF) that have a similar framework structure to our previously reported covalent organic framework membrane (TFP–DHF) but different lengths of carbon chains aiming to rationally control the pore size. The membrane permeation results in the applications of organic solvent nanofiltration and molecular sieving of organic dyes showed a systematic shift of the membrane flux and molecular weight cut-off correlated to the pore size change. These results enhanced our fundamental understanding of transport through uniform channels at nanometer scales. Pore engineering of the covalent organic framework membranes was demonstrated for the first time

    Enhancing Optical, Electronic, Crystalline, and Morphological Properties of Cesium Lead Halide by Mn Substitution for High-Stability All-Inorganic Perovskite Solar Cells with Carbon Electrodes

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    In this work all-inorganic perovskite CsPbIBr2 are doped with Mn to compensate their shortcomings in band structure for the application of perovskite solar cells (PSCs). The novel Mn-doped all-inorganic perovskites, CsPb1-xMnxI1+2xBr2-2x, are prepared in ambient atmosphere. As the concentration of Mn2+ ions increases, the bandgaps of CsPb1-xMnxI1+2xBr2-2x decrease from 1.89 to 1.75 eV. Additionally, when the concentration of Mn dopants is appropriate, this novel Mn-doped all-inorganic perovskite film shows better crystallinity and morphology than its undoped counterpart. These advantages alleviate the energy loss in hole transfer and facilitate the charge-transfer in perovskites, therefore, PSCs based on these novel CsPb1-xMnxI1+2xBr2-2x perovskite films display better photovoltaic performance than the undoped CsPbIBr2 perovskite films. The reference CsPbIBr2 cell reaches a power conversion efficiency (PCE) of 6.14%, comparable with the previous reports. The CsPb1-xMnxI1+2xBr2-2x cells reach the highest PCE of 7.36% (when x= 0.005), an increase of 19.9% in PCE. Furthermore, the encapsulated CsPb0.995Mn0.005I1.01Br1.99 cells exhibit good stability in ambient atmosphere. The storage stability measurements on the encapsulated PSCs reveal that PCE is dropped by only 8% of the initial value after >300 h in ambient. Such improved efficiency and stability are achieved using low-cost carbon electrodes (without expensive hole transport materials and Au electrodes)

    Is PTEN loss associated with clinical outcome measures in human prostate cancer?

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    Inactivating PTEN mutations are commonly found in prostate cancer, resulting in an increased activation of Akt. In this study, we investigate the role of PTEN deletion and protein expression in the development of hormone-refractory prostate cancer using matched hormone-sensitive and hormone-refractory tumours. Fluorescent in situ hybridisation and immunohistochemistry was carried out to investigate PTEN gene deletion and PTEN protein expression in the transition from hormone-sensitive to hormone-refractory prostate cancer utilising 68 matched hormone sensitive and hormone-refractory tumour pairs (one before and one after hormone relapse). Heterogeneous PTEN gene deletion was observed in 23% of hormone sensitive tumours. This increased significantly to 52% in hormone-refractory tumours (P=0.044). PTEN protein expression was observed in the membrane, cytoplasm and the nucleus. In hormone sensitive tumours, low levels of cytoplasmic PTEN was independently associated with shorter time to relapse compared to high levels of PTEN (P=0.028, hazard ratio 0.51 (95%CI 0.27–0.93). Loss of PTEN expression in the nucleus of hormone sensitive tumours was independently associated with disease-specific survival (P=0.031, hazard ratio 0.52, 95%CI 0.29–0.95). The results from this study demonstrate a role for both cytoplasmic and nuclear PTEN in progression of prostate cancer to the hormone-refractory state
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