69 research outputs found

    Member stability of stainless steel welded I-section beam-columns

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    A comprehensive experimental and numerical study is presented into the behaviour of stainless steel welded I-section beams-columns. Twenty test specimens were fabricated from grade 304 (EN 1.4301) austenitic and grade 2205 (EN 1.4406) duplex stainless steel plates – ten were tested under major axis bending plus compression and ten under minor axis bending plus compression. Material tensile coupon tests and geometric imperfection measurements were also conducted. Numerical models were developed, calibrated against the test results and subsequently employed in parametric studies considering a wider range of specimen geometries. Based on the obtained test and numerical results, the accuracy and reliability of existing design rules given in EN 1993-1-4 and AISC DG 27, as well as recent proposals, were assessed

    Systematic review of Kaixinsan in treating depression: Efficacy and pharmacological mechanisms

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    IntroductionKaixinsan (KXS) has been in use as an effective classic formulation of traditional Chinese medicine for depression. However, its active components and action mechanism against depression remain elusive. The purpose of this study was to summarize and evaluate the efficacy and potential pharmacological mechanisms of KXS in antidepressant treatment.Materials and methodsReports on the use of KXS in the treatment of depression were systematically collected from PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Chongqing VIP, and Wanfang Data from the establishment to July 2022, including those on mood disorders in neurological diseases such as Alzheimer’s disease. Meta-analysis was conducted with the Review Manager 5.3 software. Online datasets, traditional Chinese medicine system pharmacological analysis platform, GeneCards, online Mendelian inheritance in man, and DisGeNET were used to investigate the depression-related genes. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichments were performed to construct the ‘component-target-pathways’ network using Metascape online analyses.ResultTen studies were included in the analysis. Meta-analysis showed that both low-dose KXS (SMD = 19.66, Z = 7.96, and I2 = 42%) and high-dose KXS (SMD = 23.84, Z = 8.46, and I2 = 13%) could increase the sucrose preference in depression models. In addition, 5-hydroxytryptamine (5-HT) (SMD = 10.91, Z = 2.95, and I2 = 50%) returned to normal level after the treatment at low dose KXS. In network pharmacology, 50 active components and 376 gene targets were screened out. AKT1, GAPDH, ALB, TNF, and TP53 were the core target proteins. GO analysis showed that KXS mainly treats depression in biological processes such as response to drugs, cellular calcium ion homeostasis, and regulation of chemical synaptic signal transmission. KEGG results show that the mechanism of action of KXS in treating depression is through neural activity ligand-receptor interaction, the calcium signaling and CAMP signaling pathways.DiscussionThe study reveals the active components and potential molecular mechanism of KXS in the treatment of depression and provides evidence for future basic research

    Uplink Secure Receive Spatial Modulation Empowered by Intelligent Reflecting Surface

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    With the emergence of the fifth generation (5G) era, the development of the Internet of Things (IoT) network has been accelerated with a new impetus, making it imperative to strive for a more reliable and efficient network environment. To accomplish this, we introduce and investigate a novel proposal for the intelligent reflecting surface (IRS) enabled uplink secure receive spatial modulation (SM), named IRS-USRSM, to resolve the security issues arising from the open wireless transmission environment in the 5G IoT network. In the IRS-USRSM scheme, we assume that the passive eavesdropper is directly connected to the uplink user and occasionally connected to the IRS. To achieve enhanced secrecy with finite alphabet inputs, a joint transmitter perturbation and IRS reflection design for physical layer security is proposed to guarantee secure and reliable transmission of IRS-USRSM. Specifically, two categories of IRSbased random phase compensation strategies, namely, random perturbation compensation and random path synthesize, along with maximum likelihood detection and suboptimal detection are proposed to meet the variant design requirements between achieved performance and system cost. Furthermore, in order to evaluate the performance limits of the IRS-USRSM, the closedform results of average bit error probabilities and discrete-input continuous-output memoryless channel capacities are derived using the method of moment generating function. Simulation results are presented to verify the correctness of our theoretical analyses, as well as to demonstrate the efficiency and superiority of the proposed IRS-USRSM scheme

    Epidemiological investigation and analysis of Clostridium perfringens food poisoning caused by food delivery

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    Objective To find out the suspicious food, pathogenic factors and risk factors of a foodborne disease outbreak in a factory, and to discuss the problems exposed in the investigation of the incident, so as to provide reference for the prevention, control and investigation of similar incidents in the future. Methods A case was defined as the onset of abdominal pain or diarrhea (≥3 times/24 hours) or vomiting in a person who worked in M factory from March 3 to March 4 in 2019. Case interviews and retrospective research was carried out using descriptive and analytical epidemics pathological method. Stool specimens of the cases, leftover food and related environmental samples were gathered for pathogen isolation and toxin gene detection using polymerase chain reaction (PCR). Results 106 cases were identified with a attack rate of 73.6% (106/144). The symptoms were diarrhea (78.3%, 83/106), abdominal cramps (78.3%, 83/106), abdominal gas pains (9.4%, 10/106), and no fever. The epidemic curve showed a point source exposure pattern. The median incubation time was 10 hours (range: 2-22 h). Illness were associated with three food items of the lunch on March 3 in 2019 by univariate analysis and Logistic regression analysis: braised fish pieces [relative risk (RR)=1.55, 95% confidence interval (95%CI): 1.29-1.85], pork stir-fried with garlic sprouts (RR=1.26, 95%CI: 1.01-1.57) and duck blood stir-fried with pickles (RR=1.47, 95%CI: 1.16-1.87). Alpha toxin and enterotoxin CPE genes were positive and beta toxin genes was negative in the Clostridium perfringens strain isolated in anal swabs of three patients, three environmental samples and two leftover food samples. There were possible bacterial contamination and reproduction in the processing and preparation of enterprise D, which delivered food. Conclusion This incident was caused by the food poisoning of Clostridium perfringens caused by the consumption of a meal provided by a catering company. After the meal was delivered, it should be cooled quickly and stored at low temperature. If it cannot be eaten immediately, it should be heated sufficiently before eating

    Predictive model for inflammation grades of chronic hepatitis B: Large‐scale analysis of clinical parameters and gene expressions

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    BackgroundLiver biopsy is the gold standard to assess pathological features (eg inflammation grades) for hepatitis B virus‐infected patients although it is invasive and traumatic; meanwhile, several gene profiles of chronic hepatitis B (CHB) have been separately described in relatively small hepatitis B virus (HBV)‐infected samples. We aimed to analyse correlations among inflammation grades, gene expressions and clinical parameters (serum alanine amino transaminase, aspartate amino transaminase and HBV‐DNA) in large‐scale CHB samples and to predict inflammation grades by using clinical parameters and/or gene expressions.MethodsWe analysed gene expressions with three clinical parameters in 122 CHB samples by an improved regression model. Principal component analysis and machine‐learning methods including Random Forest, K‐nearest neighbour and support vector machine were used for analysis and further diagnosis models. Six normal samples were conducted to validate the predictive model.ResultsSignificant genes related to clinical parameters were found enriching in the immune system, interferon‐stimulated, regulation of cytokine production, anti‐apoptosis, and etc. A panel of these genes with clinical parameters can effectively predict binary classifications of inflammation grade (area under the ROC curve [AUC]: 0.88, 95% confidence interval [CI]: 0.77‐0.93), validated by normal samples. A panel with only clinical parameters was also valuable (AUC: 0.78, 95% CI: 0.65‐0.86), indicating that liquid biopsy method for detecting the pathology of CHB is possible.ConclusionsThis is the first study to systematically elucidate the relationships among gene expressions, clinical parameters and pathological inflammation grades in CHB, and to build models predicting inflammation grades by gene expressions and/or clinical parameters as well.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139116/1/liv13427.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139116/2/liv13427_am.pd

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
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