19 research outputs found

    The obesity paradox in intracerebral hemorrhage: a systematic review and meta-analysis

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    BackgroundIntracerebral hemorrhage (ICH) has a mortality rate which can reach 30–40%. Compared with other diseases, obesity is often associated with lower mortality; this is referred to as the ‘obesity paradox’. Herein, we aimed to summarize the studies of the relations between obesity and mortality after ICH.MethodFor this systematic review and meta-analysis (PROSPERO registry CRD42023426835), we conducted searches for relevant articles in both PubMed and Embase. Non-English language literature, irrelevant literature, and non-human trials were excluded. All included publications were then qualitatively described and summarized. Articles for which quantitative analyses were possible were evaluated using Cochrane’s Review Manager.ResultsTen studies were included. Qualitative analysis revealed that each of the 10 studies showed varying degrees of a protective effect of obesity, which was statistically significant in 8 of them. Six studies were included in the quantitative meta-analysis, which showed that obesity was significantly associated with lower short-term (0.69 [0.67, 0.73], p<0.00001) and long-term (0.62 [0.53, 0.73], p<0.00001) mortality. (Data identified as (OR [95%CI], p)).ConclusionObesity is likely associated with lower post-ICH mortality, reflecting the obesity paradox in this disease. These findings support the need for large-scale trials using standardized obesity classification methods.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023426835, identifier CRD42023426835

    Effect of Ni Addition on the Corrosion Resistance of NiTi Alloy Coatings on AISI 316L Substrate Prepared by Laser Cladding

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    In this paper, an equiatomic NiTi (55NiTi) alloy powder was mixed with pure Ni powder to prepare laser cladding coatings on a 316L stainless steel substrate to study the effect of Ni addition on the microstructure and corrosion resistance of the coatings. The microstructure and phase composition of the coatings were analyzed using a scanning electron microscope (SEM) with configured energy-dispersive spectrometer (EDS) and X-ray diffractometer (XRD). OCP (open-circuit potential), PD (potentiodynamic polarization) and EIS (electrochemical impedance spectroscopy) experiments were conducted by a Gamry electrochemical workstation, and corresponding eroded morphologies were observed to evaluate the coating’s anti-corrosion performance. The addition of Ni led to fine and uniform dendrites and dense microstructure under the metallurgical microscope, which were beneficial for the formation of the passive film mainly consisting of titanium dioxide (TiO2). The results show that the pitting potential of the 55NiTi + 5Ni coating was 0.11 V nobler than that of the 55NiTi coating, and the corrosion current density was less than half that of the 55NiTi coating. The corrosion initiated preferentially at the interfaces of dendrites and inter-dendritic areas, then spread first to dendrites rather than in the inter-dendritic areas

    Effect of filling configurations on melting heat transfer characteristic of phase change materials partially filled with metal foam

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    International audienceMetal foam embedded in phase change materials (PCM) has been shown to significantly improve the storage of latent heat thermal energy. Nonetheless the presence of metal foam also reduces natural convection, energy storage and increases cost. To address this issue, we modelled the internal flow of heat transfer in a PCM, paraffin wax, filled with metal foam at the top or the bottom, with filling height ratio ξ of 0.25, 0.5 and 0.75. The liquidsolid phase transition was studied by numerical simulations. Results show that natural convection in the pure paraffin wax area is higher, and melting time is shorter, in the bottom-filled than in the top-filled configuration. These differences increase with filling height ratio. By contrast, in metal foam-paraffin composite region, melting time is longer in the bottom-filled configuration due to heat loss. Interestingly, we observed significant changes in the interface shape of liquid-solid PCM at the junction of the pure paraffin and the metal foam-paraffin composite region. The liquid fraction formulas for different metal foam filled configurations are established as the function of Fourier number, Rayleigh number and filling height ratio

    Effect of TiO2@SiO2 nanoparticles on the mechanical and UV-resistance properties of polyphenylene sulfide fibers

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    In order to avoid the inherent photo-catalysis and aggregation of TiO2 in PPS, TiO2 nanoparticles were coated with SiO2 layers, which were chosen as the UV absorbent to improve the UV stability of polyphenylene sulfide (PPS) fiber. The PPS–TiO2@SiO2 nanocomposites fibers were prepared via melt spinning, and the nanocomposites fibers displayed different crystallization behaviors on variation of the diameters of TiO2@SiO2 nanoparticles, as confirmed by Differential Scanning Calorimetry (DSC). The spinnability, breaking strength and UV-resistance properties of PPS nanocomposites fibers, as measured by homemade melt spinning machine, Xenon-lamp Weather Resistance Test Chamber and Yarn Tensile Tester, manifested the dependence on the diameters. The addition of nanoparticles with the diameter of 25 nm improved the spinnability and the mechanical performance of PPS most, which is attributed to the heterogeneous nucleation effect of nanoparticles. The UV-resistance properties of the PPS nanocomposites were improved by the addition of TiO2@SiO2 nanoparticles. After aging for 180 h, PPS nanocomposites fiber still maintained a high strength

    Adjustable Trifunctional Mid-Infrared Metamaterial Absorber Based on Phase Transition Material VO<sub>2</sub>

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    In this paper, we demonstrate an adjustable trifunctional absorber that can achieve the conversion of broadband, narrowband and superimposed absorption based on the phase transition material vanadium dioxide (VO2) in the mid-infrared domain. The absorber can achieve the switching of multiple absorption modes by modulating the temperature to regulate the conductivity of VO2. When the VO2 film is adjusted to the metallic state, the absorber serves as a bidirectional perfect absorber with switching capability of wideband and narrowband absorption. The superposed absorptance can be generated while the VO2 layer is converted to the insulating state. Then, we introduced the impedance matching principle to explain the inner mechanism of the absorber. Our designed metamaterial system with a phase transition material is promising for sensing, radiation thermometer and switching devices

    One-step floating conversion of biomass into highly graphitized and continuous carbon nanotube yarns

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    The rapid growth of the demand for carbon nanotubes (CNTs) has greatly promoted their large-scale synthesis and development. However, the continuous production of CNT fibers by floating catalyst chemical vapor deposition (FCCVD) requires a large amount of non-renewable carbon sources. Here, the continuous production of highly graphitized CNT yarns from biomass tannic acid (TA) is reported. The chelation of TA and catalyst promotes the rapid cracking of biomass into carbon source gas, and the pyrolysis cracking produces the reducing gas, which solves the problems of the continuous production of CNT yarns using biomass. Through simple twisting, the mechanical strength of CNT yarn can reach 886 ± 46 MPa, and the electrical conductivity and graphitization (IG/ID) can reach 2 × 105 S m−1 and 6.3, respectively. This work presents a promising solution for the continuous preparation of CNT yarns based on green raw material

    HALD, a human aging and longevity knowledge graph for precision gerontology and geroscience analyses

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    Abstract Human aging is a natural and inevitable biological process that leads to an increased risk of aging-related diseases. Developing anti-aging therapies for aging-related diseases requires a comprehensive understanding of the mechanisms and effects of aging and longevity from a multi-modal and multi-faceted perspective. However, most of the relevant knowledge is scattered in the biomedical literature, the volume of which reached 36 million in PubMed. Here, we presented HALD, a text mining-based human aging and longevity dataset of the biomedical knowledge graph from all published literature related to human aging and longevity in PubMed. HALD integrated multiple state-of-the-art natural language processing (NLP) techniques to improve the accuracy and coverage of the knowledge graph for precision gerontology and geroscience analyses. Up to September 2023, HALD had contained 12,227 entities in 10 types (gene, RNA, protein, carbohydrate, lipid, peptide, pharmaceutical preparations, toxin, mutation, and disease), 115,522 relations, 1,855 aging biomarkers, and 525 longevity biomarkers from 339,918 biomedical articles in PubMed. HALD is available at https://bis.zju.edu.cn/hald
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