18 research outputs found

    Design and evaluation of rhubarb total free anthraquinones oral colon-specific drug delivery granules to improve the purgative effect

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    Rhubarb is commonly used as a cathartic in Asian countries. However, researchers have devotedextensive concerns to the quality control and safety of rhubarb and traditional Chinese preparations composed of rhubarb due to the instable purgative effect and potential nephrotoxicity of anthraquinones. In this study, we aimed to prepare rhubarb total free anthraquinones (RTFA) oral colon-specific drug delivery granules (RTFA-OCDD-GN) to delivery anthraquinones to colon to produce purgative effect. RTFAOCDD-GN were prepared using chitosan and Eudragit S100 through a double-layer coating process and the formulation was optimized. Continuous release studies were performed in a simulated gastric fluid (pH 1.2), followed by a small-intestinal fluid (pH 6.8) and a colonic fluid (pH 7.4, containing rat cecal contents). The purgative effect test was performed in rats. The dissolution profile of RTFA-OCDD-GN showed that the accumulative dissolution rate of RTFA was about 83.0% in the simulated colonic fluid containing rat cecal contents and only about 9.0% in the simulated gastrointestinal fluids. And the RTFAOCDD-GN could produce the comparative purgative activity as rhubarb, suggesting it could deliver the free AQs to the colon. The RTFA-OCDD-GN was a useful media to enhance the purgative activity of free anthraquinones after administered orally

    High Genetic Diversity of HIV-1 and Active Transmission Clusters among Male-to-Male Sexual Contacts (MMSCs) in Zhuhai, China

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    Monitoring genetic diversity and recent HIV infections (RHIs) is critical for understanding HIV epidemiology. Here, we report HIV-1 genetic diversity and RHIs in blood samples from 190 HIV-positive MMSCs in Zhuhai, China. MMSCs with newly reported HIV were enrolled from January 2020 to June 2022. A nested PCR was performed to amplify the HIV polymerase gene fragments at HXB2 positions 2604–3606. We constructed genetic transmission network at both 0.5% and 1.5% distance thresholds using the Tamura-Nei93 model. RHIs were identified using a recent infection testing algorithm (RITA) combining limiting antigen avidity enzyme immunoassay (LAg-EIA) assay with clinical data. The results revealed that 19.5% (37/190) were RHIs and 48.4% (92/190) were CRF07_BC. Two clusters were identified at a 0.5% distance threshold. Among them, one was infected with CRF07_BC for the long term, and the other was infected with CRF55_01B recently. We identified a total of 15 clusters at a 1.5% distance threshold. Among them, nine were infected with CRF07_BC subtype, and RHIs were found in 38.8% (19/49) distributed in eight genetic clusters. We identified a large active transmission cluster (n = 10) infected with a genetic variant, CRF79_0107. The multivariable logistic regression model showed that clusters were more likely to be RHIs (adjusted OR: 3.64, 95% CI: 1.51~9.01). The RHI algorithm can help to identify recent or ongoing transmission clusters where the prevention tools are mostly needed. Prompt public health measures are needed to contain the further spread of active transmission clusters

    Antibody Responses and the Effects of Clinical Drugs in COVID-19 Patients

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    The coronavirus disease 2019 (COVID-19) emerged around December 2019 and have become a global epidemic disease currently. Specific antibodies against SAS-COV-2 could be detected in COVID-19 patients’ serum or plasma, but the clinical values of these antibodies as well as the effects of clinical drugs on humoral responses have not been fully demonstrated. In this study, 112 plasma samples were collected from 36 patients diagnosed with laboratory-confirmed COVID-19 in the Fifth Affiliated Hospital of Sun Yat-sen University. The IgG and IgM antibodies against receptor binding domain (RBD) and spike protein subunit 1 (S1) of SAS-COV-2 were detected by ELISA. We found that COVID-19 patients generated specific antibodies against SARS-CoV-2 after infection, and the levels of anti-RBD IgG within 2 to 3 weeks from onset were negatively associated with the time of positive-to-negative conversion of SARS-CoV-2 nucleic acid. Patients with severe symptoms had higher levels of anti-RBD IgG in 2 to 3 weeks from onset. The use of chloroquine did not significantly influence the patients’ antibody titer but reduced C-reaction protein (CRP) level. Using anti-viral drugs (lopinavir/ritonavir or arbidol) reduced antibody titer and peripheral lymphocyte count. While glucocorticoid therapy developed lower levels of peripheral lymphocyte count and higher levels of CRP, lactate dehydrogenase (LDH), α-Hydroxybutyrate dehydrogenase(α-HBDH), total bilirubin (TBIL), direct bilirubin (DBIL). From these results, we suggested that the anti-RBD IgG may provide an early protection of host humoral responses against SAS-COV-2 infection within 2 to 3 weeks from onset, and clinical treatment with different drugs displayed distinct roles in humoral and inflammatory responses

    Design of a new type of integrated test bench for mine-used high-voltage protector

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    A new type of integrated test bench for mine-used high-voltage protector was designed. The overall structure and design schemes of software and hardware of the test bench were introduced. Fault signals are provided by the test bench which takes S7-300 PLC as a controller such as short-circuit current, over current, under-voltage, over-voltage, zero sequence over-voltage, zero sequence over-current and so on. Fault information, test items and relative hardware running status are displayed on monitoring interface of upper computer so as to detect performance of high-voltage protector quickly. Function of the test bench was tested by taking current protection function test of ZBT-11 type high-voltage protector as an example. The test result shows that the test bench can detect faults of high-voltage protector quickly and accurately. The practical application verifies perfect effect of the test bench

    A Non-Invasive Analysis of Seed Vigor by Infrared Thermography

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    This paper establishes robust regression models for fast and efficient estimation of seed vigor based on high-resolution infrared thermography. High seed quality is of great significance for agricultural and silvicultural purposes, and seed vigor is a crucial agent of seed quality. In this study, we used the non-invasive technology of infrared thermal imaging to analyze seed vigor of Ulmus pumila L. and Oryza sativa L. Temperatures of young age and aged seeds during thermal decay were monitored over time. We found that the thermal decay dynamics of U. pumila seeds were highly differential among seeds with differential vigor. Furthermore, a regression model was developed to estimate seed vigor based on its thermal decay dynamics. Similarly, a close relationship was also found between thermal decay processes and seed vigor in O. sativa. These results suggest that infrared thermography can be widely applied in non-invasive examination of seed vigor and allows fast and efficient seed screening for agricultural and silvicultural purposes in the future

    The complete chloroplast genome of Atractylodes japonica Koidz. ex Kitam. and its phylogenetic inference

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    Atractylodes japonica Koidz. ex Kitam. is a perennial herbal plant, and its dried rhizomes have been widely used as traditional medicine in China and Japan. In this study, we assembled and annotated the complete chloroplast (cp) genome sequence of A. japonica using the high-throughput sequencing approach. The cp genome of A. japonica is 153,208 bp in length with the overall GC content of 37.7%, including two inverted repeat (IR) regions of 25,147 bp, which was separated by a large single-copy (LSC) region of 84,255 bp and a small single-copy (SSC) region of 18,659 bp. 113 unique genes were annotated in the genome, including 80 protein-coding genes, 29 represented tRNA genes, and four denoted rRNA genes. A maximum-likelihood phylogenetic analysis with 38 complete cp sequences showed that Atractylodes formed a monophyletic clade, and A. japonica and A. koreana formed a subclade in Atractylodes. This study provides the chloroplast genome structure features and phylogenetic relationship of A. japonica

    Experiment on deformation and failure characteristics of sandstone at different unloading rates

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    The unloading effect is an important factor for the failure of surrounding rock in deep underground engineering projects, especially under high-stress conditions. To investigate the deformation and failure characteristics of sandstone at different unloading rates, the evolution law of the surrounding rock stress caused by excavation was clarified. Then, the single-side unloading test of surrounding rock at different unloading rates was conducted using a true triaxial rock mechanics test system. During the test, the acoustic emission (AE) signals were monitored using an AE monitoring system. The test results show that excavation disturbance leads to complete single-side unloading at the boundary of the surrounding rock, and partial single-side unloading occurs as the depth of the surrounding rock increases. The ultimate strength of the sandstone specimen decreases as a power function with the increasing unloading rate. The unloading rock mass is mainly subject to shear failure. However, the increasing unloading rate raises the proportion of tension cracks. The sudden high strain rate on the unloading side can be used as precursor information of rock fracture, which can effectively prevent accidents caused by loss of rock bearing capacity. The AE signal is active and releases less energy in the unloading stage. At this time, the internal fractures are in the development stage, and the energy is still mainly accumulated. The unloading and failure are not synchronized but suffer from the hysteresis effect. Additionally, the AE and the strain rate change on the unloading side are consistent. Due to the hysteresis effect of damage on unloading, anchor bolts (cables) should be installed to support the surrounding rock immediately to compensate for the stress loss caused by excavation in engineering practice
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