Search

Objective To improve the detection ability and to know the current situation of Chongqing point of care testing (POCT) of cardiac troponin by analyzing the external quality assessment (EQA) of cardiac troponin POCT from 2018 to 2023 in Chongqing. Methods The results of troponin POCT EQA laboratory in Chongqing Center for Clinical Laboratory from 2018 to 2023 were collected and statistically analyzed. Results From 2018 to 2023, the number of laboratories participating in Chongqing's troponin POCT EQA increased from 36 to 88, the number of instrument brand groupings used increased from none to 8, and the qualified rate of each batch of laboratories increased from the lowest 26. 32% to the highest 89.77%. However, there was still a large difference in the target values of each instrument brand grouping. The variable coefficients of grouped target value for each batch varied from 44.72% to 105.69% in 2023. Conclusion The participation rate and detection level of Chongqing cardiac troponin POCT EQA needs to be improved and troponin POCT should be continuously included in EQA plan to regularly monitor the detection quality of this project in the whole city, so as to provide rapid and reliable guarantee for clinical diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Constitutive model of stone masonry is an important foundation and prerequisite for physical calculation and finite element numerical simulation of stone masonry. In order to further study the constitutive relationship of stone masonry under uniaxial compression, based on the theory of damage mechanics, the two-parameter Weibull distribution function was applied to reflect the damage variable, and its parameters were determined according to the characteristic conditions of the whole process of the stress-strain curve of stone masonry under uniaxial compression. The uniaxial compression damage constitutive model of stone masonry was derived and established, and the correctness of the constitutive model was verified by the existing test data. The constitutive model was compared with the typical masonry constitutive model. Finally, the finite element analysis of the existing stone masonry arch bridge test was carried out to verify the applicability of the constitutive model. The results show that the model is in good agreement with the uniaxial compression test results of existing stone masonry. The established model verifies the general law of masonry damage evolution and accords with the general trend of typical masonry constitutive model. The model can be applied to the finite element analysis and calculation of masonry structure with good applicability. [ABSTRACT FROM AUTHOR]

The purpose of this project is to guide students in independently designing experiments based on problemoriented approach, taking a commonplace phenomenon (white flocs formed during laundry) as the starting point. The measurement of surface tension is integrated into the process of exploring the underlying chemical principles of daily life phenomena, and an exploratory experimental model that follows a “problem identification-practical explorationtextbook consolidation” framework is established by combining a diverse array of techniques, thereby reinforcing the students’ understanding of colloid and interface chemistry. The revised experiment offers richer content, greater challenges, enhanced comprehensiveness, and increased engagement, effectively fostering students’ abilities to analyze and solve problems and nurturing their inquisitive thinking. Furthermore, this experiment ensures a high degree of safety, ease of operation, and requires no specialized equipment, making it highly suitable for undergraduate instructional labs. [ABSTRACT FROM AUTHOR]

Objective This study aims to examine the potential mechanism of Shenfu Yixin Granules on heart failure (HF) based on network pharmacology, molecular docking, and experimental verification. Methods (1) The active components of herbs in Shenfu Yixin Granules were screened and retrieved through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) PubChem database and Swiss Target Prediction platform were used to predict targets. GeneCards and OMIM databases were used to screen HF-related targets. The intersection of active ingredient targets of Shenfu Yixin Granules and HF-related targets was performed by using Venny 2.1.0 platform to obtain common targets, which were the potential targets for anti-HF effect of Shenfu Yixin Granules. The potential targets were imported into the STRING database to construct a protein-protein interaction (PPI) network and screen the core targets of Shenfu Yixin Granules for the treatment of HF. GO functional and KEGG pathway enrichment analysis of potential targets were carried out by using DAVID database. AutoDock Vina software was used for molecular docking validation of key active ingredients and core targets. (2) SD rats were randomly allocated into sham operation group, model group, Shenfu Yixin Granules (5.28 g.kg-1) group, and positive control group (sacubitril-valsartan, 20.8 mg·kg-1), with eight rats in each group. A rat model of HF after myocardial infarction was established by ligating the left anterior descending coronary artery. The rats were subsequently administered orally with the corresponding drugs once daily for a period of four weeks. Cardiac function including left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) in rats was assessed by echocardiography. Additionally, the histopathological alterations in rat heart tissue were examined using hematoxylin-eosin (HE) staining and Masson staining. The serum levels of brain natriuretic peptide (BNP), artial natriuretic peptide (ANP), and aldosterone (ALD) were determined by enzyme-linked immunosorbent assay (ELISA). Furthermore, real-time quantitative PCR and Western Blot were employed to detect mRNA and protein expressions of CAVI、F2 and MAPKI in heart tissue. (1) A total of 210 active ingredients and 1 196 targets of Shenfu Yixin Granules, as well as 801 HF-related targets were obtained. Venny 2.1.0 platform was used to acquire 97 potential targets (common targets) of Shenfu Yixin Granules for the treatment of HF. Key active ingredients, such as quercetin, luteolin, arachidonic acid, kaempferol, and tanshinaldehyde were screened by "drugs-active ingredients-disease-targets" network analysis. The core targets including MAPK1、F2、CAV1、 EDNI and GJAI were identified through PPI network analysis. The potential targets are mainly concentrated in multiple biological processes, namely, the positive regulation of gene expression, cardiac development, and the positive regulation of MAPK cascade, and involve multi key pathways including MAPK signaling pathway, HIF-1 signaling pathway and PI3K/Akt signaling pathway etc. Good binding activities were observed between MΑΡΚΙ, CAVI, EDNI, F2 and quercetin, luteolin, kaempferol, tanshinaldehyde. as well as MAPKI, F2 and arachidonic acid. (2) Compared with sham operation group, LVEF and LVFS of rats significantly reduced (P< 0.01), heart mass index obviously increased (P < 0.05) in the model group. Myocardial tissue appears obvious pathological damage, and the degree of interstitial fibrosis was serious. The collagen volume fraction of the heart significantly increased (P < 0.01) The levels of serum BNP, ANP and ALD significantly increased (P < 0.01) The mRNA and protein expressions of CAVI、F2 and MAPK1 in heart tissue significantly increased ( P < 0.05 P< 0.01). Compared with the model group, LVEF and LVFS of rats obviously increased (P < 0.01), but the decrease in heart mass index was not significant (P > 0.05) in Shenfu Yixin Granules group and positive control group. The pathological damage in myocardial tissues was significantly improved, the degree of interstitial fibrosis was significantly reduced. The collagen volume fraction of the heart significantly decreased (P < 0.01) . The levels of serum BNP, ANP and ALD significantly decreased (P < 0.01) . The mRNA and protein expressions of CAVI、F2 and MAPKI in heart tissue significantly decreased ( P < 0.05, P < 0.01 ) . Conclusion Shenfu Yixin Granules may improve heart function and myocardial fibrosis in heart failure rats through the interaction between the active ingredients (quercetin, luteolin, arachidonic acid, kaempferol, and tanshinaldehyde) and targets (MAPK1, F2, CAV-1, and EDN1), so as to regulate MAPK signaling pathway and PI3K/Akt signaling pathway. [ABSTRACT FROM AUTHOR]

In this study, pesticide registration on kiwifruit was collated by querying the China Pesticide Information Network, and the maximum residue limit standard of pesticides for kiwifruit was collated according to China’s mandatory national standards GB 2763-2021 and GB 2763. 1-2022. The differences between China and CAC, the European Union, the United States, New Zealand, Japan and South Korea in the current kiwifruit limit standards were systematically analyzed, and suggestions were put forward on the revision of pesticide residue limit standards, safe drug use, quality control and reducing the risk of technical barriers, so as to provide reference for the high-quality development of kiwifruit industry in China. [ABSTRACT FROM AUTHOR]

The coastal waters along the northern Shandong Peninsula waters is rich in fishery resources, which is the passing fishing ground for economic organisms to enter the Bohai Sea to spawn and leave for winter. In recent years, overfishing and pollution have caused considerable damage to fishery resources there, and zooplankton has been adversely affected. Based on sampling data in this area from 2016 to 2017, the spatial and temporal distribution, structure community, dominant species and diversity indices of zooplankton community were analyzed. 39 species of zooplankton and 13 classes zooplankton larvae were record during the four surveys, which belonged to 11 phyla and most species were found in autumn. The dominant species had obvious seasonal change, Calanus sinicus, Labidocera bipinnata and Sagitta crassa were the main dominant species record, among them, Calanus sinicus was the dominant species in four surveys. Influenced by the Bolai coastal current, Yellow Sea warm current and Yellow Sea cold water mass, the seasonal variation of zooplankton abundance was obvious, with the highest abundance (147.1 ind·m–3) in spring and the lowest abundance (37.3 ind·m–3) in winter. The horizontal distribution of zooplankton abundance was uneven, with higher abundance in the western ocean near Zhifu Island in spring and autumn, while the concentration center located in the eastern ocean near Weihai in summer and winter. [ABSTRACT FROM AUTHOR]

In offshore fracturing operation, formulating a fracturing fluid with fresh water results in high transportation cost and long time of formulation. If seawater is used to formulate the fracturing fluid, a large amount of chelating agents which crosslink in alkaline environment shall be used, and this results in high material cost, while the ability of the fracturing fluid formulated to resist high temperature may not be satisfactory. To solve this problem, an organic titanium zirconium crosslinking agent is stepwise synthesized with reactants tetra-isopropyl titanate and zirconium sulphate etc. Characterization of the reaction product with NMR and SEM (after precipitation of the crosslinking agent) shows that the crosslinking agent is an organic chelating agent. The particle sizes of the crosslinking agent are distributed in a range of 1 nm to 100 nm, as measured with dynamic and static synchronous laser scattering instrument, and this indicates that the crosslinking agent has excellent reactivity. This crosslinking agent can crosslink in neutral conditions, a good property for formulating fracturing fluids with high salinity waters such as seawater. The microstructure of the crosslinking product is a stable honeycomb-like hexagonal grid structure. With this organic titanium-zirconium crosslinking agent, the fracturing fluids formulated have better viscoelasticity than the fracturing fluids formulated with crosslinking agents containing only titanium. The high temperature resistance of the fracturing fluids formulated using the organic titanium-zirconium crosslinking agent is 180 ℃. Field application of this new crosslinking agent in formulating a fracturing fluid with seawater for fracturing a high temperature well of CNOOC in south China Sea has obtained good results [ABSTRACT FROM AUTHOR]