52 research outputs found
Advances in genetic variation in metabolism-related fatty liver disease
Metabolism-related fatty liver disease (MAFLD) is the most common form of chronic liver disease in the world. Its pathogenesis is influenced by both environmental and genetic factors. With the upgrading of gene screening methods and the development of human genome project, whole genome scanning has been widely used to screen genes related to MAFLD, and more and more genetic variation factors related to MAFLD susceptibility have been discovered. There are genetic variants that are highly correlated with the occurrence and development of MAFLD, and there are genetic variants that are protective of MAFLD. These genetic variants affect the development of MAFLD by influencing lipid metabolism and insulin resistance. Therefore, in-depth analysis of different mechanisms of genetic variation and targeting of specific genetic variation genes may provide a new idea for the early prediction and diagnosis of diseases and individualized precision therapy, which may be a promising strategy for the treatment of MAFLD
The multidrug-resistant Pseudomonas fluorescens strain: a hidden threat in boar semen preservation
Although the bacterial composition of boar ejaculate has been extensively studied, the bacterial composition of extended boar semen is often overlooked, despite the potential risks these microorganisms may pose to the long-term preservation of extended boar semen at 15–17°C. In this study, we characterized the bacterial community composition of extended semen and discovered that Pseudomonas spp. was the dominant flora. The dominant strains were further isolated and identified as a potential new species in the Pseudomonas fluorescens group and named GXZC strain, which had adverse effects on sperm quality and was better adapted to growth at 17°C. Antimicrobial susceptibility testing showed that the GXZC strain was resistant to all commonly used veterinary antibiotics. Whole-genome sequencing (WGS) and genome annotation revealed the large genetic structure and function [7,253,751 base pairs and 6,790 coding sequences (CDSs)]. Comparative genomic analysis with the closest type strains showed that the GXZC strain predicted more diversity of intrinsic and acquired resistance genes to multi-antimicrobial agents. Taken together, our study highlights a problem associated with the long-term storage of extended boar semen caused by a P. fluorescens group strain with unique biological characteristics. It is essential to develop a new antibacterial solution for the long-term preservation of boar semen
Identification of a novel peptide targeting TIGIT to evaluate immunomodulation of 125I seed brachytherapy in HCC by near-infrared fluorescence
IntroductionHepatocellular carcinoma (HCC) has very poor prognosis due to its immunosuppressive properties. An effective measure to regulate tumor immunity is brachytherapy, which uses 125I seeds planted into tumor. T cell immune receptors with immunoglobulin and ITIM domains (TIGIT) is highly expressed in HCC. The TIGIT-targeted probe is expected to be an effective tool for indicating immunomodulation of 125I seed brachytherapy in HCC. In this study, We constructed a novel peptide targeting TIGIT to evaluate the immune regulation of 125I seed brachytherapy for HCC by near-infrared fluorescence (NIRF).MethodsExpression of TIGIT by immunofluorescence (IF) and flow cytometry (FCM) in different part and different differentiated human liver cancer tissues was verified. An optical fluorescence probe (Po-12) containing a NIRF dye and TIGIT peptide was synthesized for evaluating the modulatory effect of 125I seed brachytherapy. Lymphocytes uptake by Po-12 were detected by FCM and confocal microscopy. The distribution and accumulation of Po-12 in vivo were explored by NIRF imaging in subcutaneous and orthotopic tumors. IHC and IF staining were used to verify the expression of TIGIT in the tumors.ResultsTIGIT was highly expressed in HCC and increased with tumor differentiation. The dye-labeled peptide (Po-12) retained a stable binding affinity for the TIGIT protein in vitro. Accumulation of fluorescence intensity (FI) increased with time extended in subcutaneous H22 tumors, and the optimal point is 1 h. TIGIT was highly expressed on lymphocytes infiltrated in tumors and could be suppressed by 125I seed brachytherapy. Accumulation of Po-12-Cy5 was increased in tumor-bearing groups while declined in 125I radiation group
Occurrence of False Positive Results for the Detection of Carbapenemases in Carbapenemase-Negative Escherichia coli and Klebsiella pneumoniae Isolates
Adequate detection of the production of carbapenemase in Enterobacteriaceae isolates is crucial for infection control measures and the appropriate choice of antimicrobial therapy. In this study, we investigated the frequency of false positive results for the detection of carbapenemases in carbapenemase-negative Escherichia coli and Klebsiella pneumoniae clinical isolates by the modified Hodge test (MHT). Three hundred and one E. coli and K. pneumoniae clinical isolates were investigated. All produced extended spectrum β-lactamases (ESBLs) but were susceptible to carbapenems. Antimicrobial susceptibility testing was performed by the disk diffusion and agar dilution methods. The MHT was performed using the standard inoculum of test organisms recommended by the CLSI. Genes that encoded ESBLs and carbapenemases were identified by PCR and DNA sequencing. Among the 301 clinical isolates, none of the isolates conformed to the criteria for carbapenemase screening recommended by the CLSI. The susceptibility rates for imipenem, meropenem, and ertapenem all were 100.0%, 100.0%, and 100.0%, respectively. Of the 301 E. coli and K. pneumoniae isolates, none produced carbapenemase. The MHT gave a positive result for 3.3% (10/301) of the isolates. False positive results can occur when the MHT is used to detect carbapenemase in ESBL-producing isolates and clinical laboratories must be aware of this fact
Study on Dynamic Load of Air-Conditioning System in Subway Station Based on Hourly Passenger Flow
The research focuses on the air-conditioning system in a public area of a subway station. To address this, an optimization model based on the grid time segmentation method was constructed, specifically a GM (1,1) model. We explored the influence of the hourly passenger flow fluctuation on the load of the subway air-conditioning system, obtained the dynamic change law of the air conditioning system load in the subway station, and then dynamically adjusted the air conditioning system according to the dynamic change law to reduce the operation energy consumption of the system. Through the analysis of the simulation results, the model predicted that compared with the actual passenger flow data, the average maximum relative error was 14.97%. On this basis, the change law of the dynamic load of the subway air-conditioning system which caused by the change in passenger flow from time to time could be calculated and analyzed. Compared with the calculated load of the air conditioning system, the working day load was decreased by 1469.77 kW, or 22.00%. The findings indicate that in response to the dynamic load of fluctuations, timely adjustment of the air supply parameter of the air-conditioning system offers a significant reference point for optimizing energy efficiency in subway stations
Analytical DC-side stabilizing conditions for hybrid HVDC links based on dominant frequency model reduction
Incorporating the advantages of line commutated converters (LCCs) and voltage-source converters (VSCs), hybrid high voltage DC (HVDC) links have bright prospects in bulk power transmission. For this new technique, however, there is a risk of oscillatory instability in the DC link, and the mechanism behind the instability is still unclear. This paper derives analytical DC-side stabilizing conditions for hybrid HVDC links by using dominant frequency model reduction. The small-signal model of the LCC-VSC link is first truncated by reserving only the state variables highly relevant to the dominant mode so that the expression of the dominant oscillation frequency can be obtained. Dynamics of other state variables are reintroduced and then simplified while leaving their properties nearby the dominant frequency intact. Based on the reduced model, an analytical stability criterion is obtained, which reveals that the DC-side stability of hybrid HVDC links will deteriorate with reduced DC voltage operation, a heavy load, a small DC-link capacitor, slow inner loop dynamics, a small proportional and a large integral gain of the DC voltage regulator. In addition, simplified sufficient stabilizing conditions of hybrid HVDC links are further derived for control parameter design. Case studies validate the accuracy of dominant frequency model reduction and the derived stabilizing conditions
Cloning the Horse RNA Polymerase I Promoter and Its Application to Studying Influenza Virus Polymerase Activity
An influenza virus polymerase reconstitution assay based on the human, dog, or chicken RNA polymerase I (PolI) promoter has been developed and widely used to study the polymerase activity of the influenza virus in corresponding cell types. Although it is an important member of the influenza virus family and has been known for sixty years, no studies have been performed to clone the horse PolI promoter or to study the polymerase activity of equine influenza virus (EIV) in horse cells. In our study, the horse RNA PolI promoter was cloned from fetal equine lung cells. Using the luciferase assay, it was found that a 500 bp horse RNA PolI promoter sequence was required for efficient transcription. Then, using the developed polymerase reconstitution assay based on the horse RNA PolI promoter, the polymerase activity of two EIV strains was compared, and equine myxovirus resistance A protein was identified as having the inhibiting EIV polymerase activity function in horse cells. Our study enriches our knowledge of the RNA PolI promoter of eukaryotic species and provides a useful tool for the study of influenza virus polymerase activity in horse cells
Sequence-controlled polymers constructed by alkyne-based polymerizations
Synthesizing polymers with precise sequence structures is of great significance but is still a great challenge in polymer science. The exploration of alkyne-based polymerizations recently has attracted considerable attention due to their great potential to construct polymers with diverse structures and versatile functions, especially those with precise sequence structures. In this review, we summarized recent advances in the preparation of sequence-controlled polymers by alkyne-base polymerizations. Representative examples of each method were selected to illustrate the essential construction principles and implementation approaches, which are expected to provide guidance for the development of sequence-controlled polymers. In addition, we also systematically introduce the diverse and appealing properties and applications of the obtained sequence-controlled polymers, hoping to promote the development of polymeric materials with more superior and innovative properties and applications
S1PR1 Is Crucial for Accumulation of Regulatory T Cells in Tumors via STAT3
S1PR1 signaling has been shown to restrain the number and function of regulatory T (Treg) cells in the periphery under physiological conditions and in colitis models, but its role in regulating tumor-associated TÂ cells is unknown. Here, we show that S1PR1 signaling in TÂ cells drives Treg accumulation in tumors, limits CD8+ TÂ cell recruitment and activation, and promotes tumor growth. T-cell-intrinsic S1PR1 affects Treg cells, but not CD8+ TÂ cells, as demonstrated by adoptive transfer models and transient pharmacological S1PR1 modulation. An increase in S1PR1 in CD4+ TÂ cells promotes STAT3 activation and JAK/STAT3-dependent Treg tumor migration, whereas STAT3 ablation in TÂ cells diminishes tumor-associated Treg accumulation and tumor growth. Our study demonstrates a stark contrast between the consequences of S1PR1 signaling in Treg cells in the periphery versus tumors
Online Detection and Classification of Moldy Core Apples by Vis-NIR Transmittance Spectroscopy
Apple moldy core disease is a common internal fungal disease. The online detection and classification of apple moldy core plays a vital role in apple postharvest processing. In this paper, an online non-destructive detection system for apple moldy core disease was developed using near-infrared transmittance spectroscopy in spectral range of 600–1100 nm. A total of 120 apple samples were selected and randomly divided into a training set and a test set based on the ratio of 2:1. First, basic parameters for detection of apples with moldy core were determined through detection experiments of samples in a stationary state. Due to the random distribution of the diseased tissue inside diseased apples, stationary detection cannot accurately identify the diseased tissue. To solve this problem, the spectra of apples in motion state transmitted forward by the transmission line were acquired. Three placement orientations of the apple in the carrying fruit cup were tested to explore the influence of fruit orientation on spectral characteristics and prediction. According to the performance of the model, the optimal preprocessing method and modeling method were determined (fixed orientation model and arbitrary orientation model). SPA was used to select the characteristic wavelengths to further improve the online detection speed. The overall results showed that the multi-spectra model using mean spectra of three orientations was the best. The prediction accuracies of multi-spectra model using SPA for three orientations were 96.7%, 97.5% and 97.5% respectively. As a conclusion, the arbitrary orientation model was beneficial to improve the online detection of apple moldy core disease
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