1,225 research outputs found

    An integrated method for net-shape manufacturing components combining 3D additive manufacturing and compressive forming processes

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    Additive manufactured (AM) or 3D printed metallic components suffer poor and inconsistent mechanical properties due to the presence of a large number of micro-voids, residual stress and microstructure inhomogeneity. To overcome these problems, a new forming process has been proposed, which effectively combines AM and compressive forming. The aim of this study is to prove the feasibility of this newly proposed method by providing preliminary results. Thus, we compared the tensile performance of hot-forged additive manufactured stainless steel 316L samples to none-hot-forged additive manufactured ones. Significant improvement in mechanical properties has been found in the tensile tests as well hardness test. In addition, our EBSD characterized grain orientation maps at each stage of the process revealed the corresponding microstructure revolution which provides insights into underlying mechanistic

    Hepatic cell mobilization for protection against ischemic myocardial injury

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    The heart is capable of activating protective mechanisms in response to ischemic injury to support myocardial survival and performance. These mechanisms have been recognized primarily in the ischemic heart, involving paracrine signaling processes. Here, we report a distant cardioprotective mechanism involving hepatic cell mobilization to the ischemic myocardium in response to experimental myocardial ischemia–reperfusion (MI-R) injury. A parabiotic mouse model was generated by surgical skin-union of two mice and used to induce bilateral MI-R injury with unilateral hepatectomy, establishing concurrent gain- and loss-of-hepatic cell mobilization conditions. Hepatic cells, identified based on the cell-specific expression of enhanced YFP, were found in the ischemic myocardium of parabiotic mice with intact liver (0.2 ± 0.1%, 1.1 ± 0.3%, 2.7 ± 0.6, and 0.7 ± 0.4% at 1, 3, 5, and 10 days, respectively, in reference to the total cell nuclei), but not significantly in the ischemic myocardium of parabiotic mice with hepatectomy (0 ± 0%, 0.1 ± 0.1%, 0.3 ± 0.2%, and 0.08 ± 0.08% at the same time points). The mobilized hepatic cells were able to express and release trefoil factor 3 (TFF3), a protein mitigating MI-R injury as demonstrated in TFF3−/− mice (myocardium infarcts 17.6 ± 2.3%, 20.7 ± 2.6%, and 15.3 ± 3.8% at 1, 5, and 10 days, respectively) in reference to wildtype mice (11.7 ± 1.9%, 13.8 ± 2.3%, and 11.0 ± 1.8% at the same time points). These observations suggest that MI-R injury can induce hepatic cell mobilization to support myocardial survival by releasing TFF3

    Characterization of high-resolution aerosol mass spectra of primary organic aerosol emissions from Chinese cooking and biomass burning

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    Aerosol mass spectrometry has proved to be a powerful tool to measure submicron particulate composition with high time resolution. Factor analysis of mass spectra (MS) collected worldwide by aerosol mass spectrometer (AMS) demonstrates that submicron organic aerosol (OA) is usually composed of several major components, such as oxygenated (OOA), hydrocarbon-like (HOA), biomass burning (BBOA), and other primary OA. In order to help interpretation of component MS from factor analysis of ambient OA datasets, AMS measurements of different primary sources is required for comparison. Such work, however, has been very scarce in the literature, especially for high resolution MS (HR-MS) measurements, which performs improved characterization by separating the ions of different elemental composition at each <i>m</i>/<i>z</i> in comparison with unit mass resolution MS (UMR-MS) measurements. In this study, primary emissions from four types of Chinese cooking (CC) and six types of biomass burning (BB) were simulated systematically and measured using an Aerodyne High-Resolution Time-of-Flight AMS (HR-ToF-AMS). The MS of the CC emissions show high similarity, with <i>m</i>/<i>z</i> 41 and <i>m</i>/<i>z</i> 55 being the highest signals; the MS of the BB emissions also show high similarity, with <i>m</i>/<i>z</i> 29 and <i>m</i>/<i>z</i> 43 being the highest signals. The MS difference between the CC and BB emissions is much bigger than that between different CC (or BB) types, especially for the HR-MS. The O/C ratio of OA ranges from 0.08 to 0.13 for the CC emissions and from 0.18 to 0.26 for the BB emissions. The UMR ions of <i>m</i>/<i>z</i> 43, <i>m</i>/<i>z</i> 44, <i>m</i>/<i>z</i> 57, and <i>m</i>/<i>z</i> 60, usually used as tracers in AMS measurements, were examined for their HR-MS characteristics in the CC and BB emissions. In addition, the MS of the CC and BB emissions are also compared with component MS from factor analysis of ambient OA datasets observed in China, as well as with other AMS measurements of primary sources in the literature. The MS signatures of cooking and biomass burning emissions revealed in this study can be used as important reference for factor analysis of ambient OA datasets, especially for the relevant studies in East Asia

    Therapeutic effect of Dongbai-Tonglin-Fang, a Chinese herbal formula, on urinary tract infection in rat model.

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    ETHNOPHARMACOLOGICAL RELEVANCE: Traditional Chinese Medicine (TCM) has many obvious advantages in the treatment of chronic conditions such as urinary tract infection (UTI). Dongbai-Tonglin-Fang (DBTL), a Chinese herbal formula, has been used for the treatment of UTI for more than 40 years with proven efficacy. However, its mechanism of action is still unknown. AIM OF THE STUDY: The purpose of this study is to evaluate the therapeutic efficacy of DBTL and its mechanism of action in a rat UTI model. MATERIALS AND METHODS: E. coli solution induced UTI rat model was used to evaluate the therapeutic effect of DBTL on UTI. Biochemical indicators related to UTI were measured. The kidney tissue was stained with hematoxylin-eosin (HE) to observe pathological changes whilst the ear swelling, feet swelling, hot plate and body torsion tests were used to estimate the anti-inflammatory and analgesic effects of DBTL. RESULTS: After treatment with different doses of DBTL (1, 2, 4 g/kg), a decrease in weight of the kidney in the UTI rat model was observed. The contents of white blood cell, nitrite, urinary albumin, ketone body, bilirubin and occult blood in the urine were also reduced whilst an increase in the pH of urine was observed. HE staining showed that the pathological changes in the kidney tissue were alleviated. At the same time, ear swelling assay showed that the weight and the degree of swelling of the ear of the mice in DBTL groups were decreased remarkably. DBTL also reduced the degree of feet swelling of the rats caused by the adjuvant. Furthermore, with the DBTL treatment, the latency period of foot licking induced by thermal stimulation was increased while the number of twists was lessened. CONCLUSION: These results show that DBTL has an excellent therapeutic effect on UTI rats accompanying with anti-inflammation and analgesia. The data presented here lays the foundations for further investigations in the treatment of UTI

    Time series canopy phenotyping enables the identification of genetic variants controlling dynamic phenotypes in soybean

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    Advances in plant phenotyping technologies are dramatically reducing the marginal costs of collecting multiple phenotypic measurements across several time points. Yet, most current approaches and best statistical practices implemented to link genetic and phenotypic variation in plants have been developed in an era of single-time-point data. Here, we used time-series phenotypic data collected with an unmanned aircraft system for a large panel of soybean (Glycine max (L.) Merr.) varieties to identify previously uncharacterized loci. Specifically, we focused on the dissection of canopy coverage (CC) variation from this rich data set. We also inferred the speed of canopy closure, an additional dimension of CC, from the time-series data, as it may represent an important trait for weed control. Genome-wide association studies (GWASs) identified 35 loci exhibiting dynamic associations with CC across developmental stages. The time-series data enabled the identification of 10 known flowering time and plant height quantitative trait loci (QTLs) detected in previous studies of adult plants and the identification of novel QTLs influencing CC. These novel QTLs were disproportionately likely to act earlier in development, which may explain why they were missed in previous single-time-point studies. Moreover, this time-series data set contributed to the high accuracy of the GWASs, which we evaluated by permutation tests, as evidenced by the repeated identification of loci across multiple time points. Two novel loci showed evidence of adaptive selection during domestication, with different genotypes/haplotypes favored in different geographic regions. In summary, the time-series data, with soybean CC as an example, improved the accuracy and statistical power to dissect the genetic basis of traits and offered a promising opportunity for crop breeding with quantitative growth curves

    Centralized Inverted Decoupling Control

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    This paper presents a new methodology of multivariable centralized control based on the structure of inverted decoupling. The method is presented for general n×n processes, obtaining very simple general expressions for the controller elements with a complexity independent of the system size. The possible configurations and realizability conditions are stated. Then, the specification of performance requirements is carried out from simple open loop transfer functions for three common cases. As a particular case, it is shown that the resulting controller elements have PI structure or filtered derivative action plus a time delay when the process elements are given by first order plus time delay systems. Comparisons with other works demonstrate the effectiveness of this methodology through the use of several simulation examples and an experimental lab process

    Fast response electromagnetic follow-ups from low latency GW triggers

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    © Published under licence by IOP Publishing Ltd. We investigate joint low-latency gravitational wave (GW) detection and prompt electromagnetic (EM) follow-up observations of coalescing binary neutron stars (BNSs). Assuming that BNS mergers are associated with short duration gamma ray bursts (SGRBs), we evaluate if rapid EM follow-ups can capture the prompt emission, early engine activity or reveal any potential by-products such as magnetars or fast radio bursts. To examine the expected performance of extreme low-latency search pipelines, we simulate a population of coalescing BNSs and use these to estimate the detectability and localisation efficiency at different times before merger. Using observational SGRB flux data corrected to the range of the advanced GW interferometric detectors, we determine what EM observations could be achieved from low-frequency radio up to high energy ?-ray. We show that while challenging, breakthrough multi-messenger science is possible through low latency pipelines
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