66 research outputs found
QIDANTONGMAI PROTECTS ENDOTHELIAL CELLS AGAINST HYPOXIA-INDUCED DAMAGE THROUGH REGULATING THE SERUM VEGF-A LEVEL
Qidantongmai (QDTM) is a Traditional Chinese Medicine (TCM) preparation that has long been used in folk medicine for the treatment of cardiovascular diseases. However, the underlying mechanisms are poorly understood. The present study was designed to determine the effects of QDTM on endothelial cells under hypoxic conditions both in vitro and in vivo. Primary human umbilical vein endothelial cells (HUVECs) were isolated, pretreated with QDTM medicated serum or saline control, and then cultured under hypoxia (2% oxygen) for 24 h. Sprague-Dawley rats were administered 1 ml/100 g of QDTM or saline twice a day for 4 days and treated with hypoxia (6 hours/day, discontinuous hypoxia, 360 mm Hg). QDTM not only protected HUVECs from hypoxia-induced damage by significantly retaining cell viability (P < 0.05) and decreasing apoptosis (P < 0.05) in vitro, but also protected liver endothelial cells from hypoxia-induced damage in vivo. Moreover, QDTM increased the serum VEGF-A level (P < 0.05) in rats treated with hypoxia for 7 days but suppressed the upregulation of serum VEGF-A in rats treated with hypoxia for 14 days. QDTM is a potent preparation that can protect endothelial cells against hypoxia-induced damage. The ability of QDTM to modulate the serum VEGF-A level may play an important role in its effects on endothelial cells
Red blood cell distribution width combined with age as a predictor of acute ischemic stroke in stable COPD patients
AimThis retrospective study aimed to investigate the independent clinical variables associated with the onset of acute cerebral ischemic stroke (AIS) in patients with stable chronic obstructive pulmonary disease (COPD).MethodA total of 244 patients with COPD who had not experienced a relapse within 6 months were included in this retrospective study. Of these, 94 patients hospitalized with AIS were enrolled in the study group, and the remaining 150 were enrolled in the control group. Clinical data and laboratory parameters were collected for both groups within 24 h after hospitalization, and the data of the two groups were statistically analyzed.ResultsThe levels of age, white blood cell (WBC), neutrophil (NEUT), glucose (GLU), prothrombin time (PT), albumin (ALB), and red blood cell distribution width (RDW) were different in the two groups (P < 0.01). Logistic regression analysis showed that age, WBC, RDW, PT, and GLU were independent risk factors for the occurrence of AIS in patients with stable COPD. Age and RDW were selected as new predictors, and the receiver operating characteristic curves (ROC) were plotted accordingly. The areas under the ROC curves of age, RDW, and age + RDW were 0.7122, 0.7184, and 0.7852, respectively. The sensitivity was 60.5, 59.6, and 70.2%, and the specificity was 72.4, 86.0, and 60.0%, respectively.ConclusionThe combination of RDW and age in patients with stable COPD might be a potential predictor for the onset of AIS
Cell transcriptomic atlas of the non-human primate Macaca fascicularis.
Studying tissue composition and function in non-human primates (NHPs) is crucial to understand the nature of our own species. Here we present a large-scale cell transcriptomic atlas that encompasses over 1 million cells from 45 tissues of the adult NHP Macaca fascicularis. This dataset provides a vast annotated resource to study a species phylogenetically close to humans. To demonstrate the utility of the atlas, we have reconstructed the cell-cell interaction networks that drive Wnt signalling across the body, mapped the distribution of receptors and co-receptors for viruses causing human infectious diseases, and intersected our data with human genetic disease orthologues to establish potential clinical associations. Our M. fascicularis cell atlas constitutes an essential reference for future studies in humans and NHPs.We thank W. Liu and L. Xu from the Huazhen Laboratory Animal Breeding
Centre for helping in the collection of monkey tissues, D. Zhu and H. Li from the Bioland
Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory) for
technical help, G. Guo and H. Sun from Zhejiang University for providing HCL and MCA gene
expression data matrices, G. Dong and C. Liu from BGI Research, and X. Zhang, P. Li and C. Qi
from the Guangzhou Institutes of Biomedicine and Health for experimental advice or providing
reagents. This work was supported by the Shenzhen Basic Research Project for Excellent
Young Scholars (RCYX20200714114644191), Shenzhen Key Laboratory of Single-Cell Omics
(ZDSYS20190902093613831), Shenzhen Bay Laboratory (SZBL2019062801012) and Guangdong Provincial Key Laboratory of Genome Read and Write (2017B030301011). In
addition, L.L. was supported by the National Natural Science Foundation of China (31900466),
Y. Hou was supported by the Natural Science Foundation of Guangdong Province
(2018A030313379) and M.A.E. was supported by a Changbai Mountain Scholar award
(419020201252), the Strategic Priority Research Program of the Chinese Academy of Sciences
(XDA16030502), a Chinese Academy of Sciences–Japan Society for the Promotion of Science
joint research project (GJHZ2093), the National Natural Science Foundation of China
(92068106, U20A2015) and the Guangdong Basic and Applied Basic Research Foundation
(2021B1515120075). M.L. was supported by the National Key Research and Development
Program of China (2021YFC2600200).S
Formulation and Assessment of a Customizable Procedure for Pavement Distress Index
A customizable procedure for the formulation of Pavement Distress Index (PDI) based on human rating behavior is presented in this dissertation. This procedure formulates PDI as the maximum PDI value in a user-defined scale minus the Total Deduct Value (TDV), which is the sum of the product of each individual Deduct-Value (DV) and its corresponding weight. These weights, defined as a function of corresponding DV-percentages, i.e. individual DV over TDV, are identified using data simulated according to the studies by Sun and Yao (1991) and PAVER, a Pavement Management System (PMS) developed by the U. S. Army Corps of Engineers. Because these functions, called weight-curves captured from the two independent studies are quite similar, the rating behavior of pavement experts can be concluded to be reasonably stable, and therefore PDI may be formulated by fixing the weight-curve and customizing individual DVs only.
Non-linear programming techniques are employed in this study. DVs for userdefined distresses are determined when the total squared sum of the difference between user-rated PDI and that computed by the proposed formulation for a series of samples is minimized. Initially, simulated data from PAVER was used to establish and illustrate this procedure. Field data was later on used for validation purposes. The proposed methodology caters to user-defined PDI scales and distress definitions, and determines DVs for user-defined distresses so that the user-rated PDIs can be reproduced when similar pavement conditions happen. This procedure simplified the iterative PDI formulation process to the automated customization of deduct-values, it would thus greatly facilitate the formulation of a PDI for agencies that are implementing a PMS
Achieving Enhanced Sound Insulation through Micromembranes-Type Acoustic Metamaterials
Acoustic micromembranes (AμMs) are attracting more and more attention due to their unparalleled light weight but high sound transmission loss (STL) at low frequencies. Previous works showed that AμMs feature remarkable sound insulation compared to homogeneous plates with the same surface mass density, while some follow-up works claimed that the outstanding insulation capability of small AμMs samples disappears when the sample size grows. To uncover the working mechanisms underpinning the unique behavior of AμMs, in this paper, we present theoretical and numerical studies of AμMs that couple the vibrations of the supporting frame and the AμMs within the lattice. The results show how the global response in the STL of the AμMs assembly is related to the geometrical parameters of AμMs cells and the lattice. This study provides a theoretical foundation for designing a large-scale yet high-insulation assembly of AμMs, and paves the way for applying AμMs for blocking low-frequency noise
Quality evaluation of design alternatives of vessel based on improved cloud barycenter method
[Objectives] To deal with uncertainties in the quality evaluation of alternative navy vessel designs,the cloud barycenter evaluation method is introduced.[Methods] The basic concept of cloud theory is expounded upon and the evaluation principle and basic process of the cloud barycenter method are analyzed. The existing cloud barycenter algorithm cannot effectively express the matching degree between quality characteristics and user requirement. The improvement of the cloud barycenter algorithm is realized by defining the quality matching degree. Due to the small amount of data,the accuracy of the evaluation express is insufficient. The evaluation data can be effectively extended through the cloud generator so as to better express the evaluation results. On this basis,the method is analyzed according to alternative vessel design choices. [Results] The results show that the improved method has good adaptability to the problems,and the evaluation results are in accordance with the quality evaluation requirements of the alternative naval vessel design.[Conclusions] The findings of this paper can provide valuable references for the application of the cloud barycenter method and new ideas for the selection of alternative navy vessel design
DenseTrans: Multimodal Brain Tumor Segmentation Using Swin Transformer
Aiming at the task of automatic brain tumor segmentation, this paper proposes a new DenseTrans network. In order to alleviate the problem that convolutional neural networks(CNN) cannot establish long-distance dependence and obtain global context information, swin transformer is introduced into UNet++ network, and local feature information is extracted by convolutional layer in UNet++. then, in the high resolution layer, shift window operation of swin transformer is utilized and self-attention learning windows are stacked to obtain global feature information and the capability of long-distance dependency modeling. meanwhile, in order to alleviate the secondary increase of computational complexity caused by full self-attention learning in transformer, deep separable convolution and control of swin transformer layers are adopted to achieve a balance between the increase of accuracy of brain tumor segmentation and the increase of computational complexity. on BraTs2021 data validation set, model performance is as follows: the dice dimilarity score was 93.2%,86.2%,88.3% in the whole tumor,tumor core and enhancing tumor, hausdorff distance(95%) values of 4.58mm,14.8mm and 12.2mm, and a lightweight model with 21.3M parameters and 212G flops was obtained by depth-separable convolution and other operations. in conclusion, the proposed model effectively improves the segmentation accuracy of brain tumors and has high clinical value
Transient electric field computation for composite cross-arm in 750 kV AC transmission line under lightning impulse voltage
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Synergetic enhancement of mechaniCal and electrical strength in epoxy/silica nanocomposites via chemically-bonded interface
While the incorporation of the inorganic fillers into polymers is envisioned to improve the properties of polymers, the organic–inorganic interface in the nanocomposite plays a prominent role in the modulation of the electrical, mechanical and thermal properties. Here, the epoxy chain-grafted silica nanoparticles were prepared and utilized as the fillers in epoxy matrix. The multiple physical properties such as the tensile strength, the elongation at break, the glass transition temperature, the dielectric strength of the nanocomposites with epoxy chain-grafted silica are simultaneously improved in comparison with those of the neat epoxy and the nanocomposites with unmodified silica. Moreover, substantial reductions in the water absorption ratio, dielectric loss and electric conductivity are obtained in the nanocomposites filled with epoxy-grafted silica even at relatively low filler loadings. These results verify the critical role of the chemically-bonded interface between organic and inorganic phases in determining the mechanical and dielectric strength of the polymer nanocomposites. The interaction zone models for the interface between nanoparticle and polymer matrix have been proposed to rationalize the experimental results
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