Cats, owing to their physiological and immunological similarities with humans, have become increasingly valuable as model animals in virology research, drug development, and vaccine evaluation. They are irreplaceable in studies of feline immunodeficiency virus, feline coronavirus, and other related pathogens. However, cats are temperamentally sensitive, exhibit strong stress responses, and possess well-developed nervous systems as well as sharp claws and teeth. Consequently, the biosafety risks associated with infectious experiments using cats in animal biosafety level 2 laboratory (ABSL-2) are significantly higher than those encountered with conventional rodents. Drawing on long-term ABSL-2 operational experience, this article systematically reviews the entire workflow of infectious experiments in laboratory cats — from animal selection, pre-entry preparation, reception and quarantine, housing management, to infectious experimental procedures and incident response — identifying and addressing critical risk points at each stage. For strain selection, SPF-grade shorthair cats with defined genetic backgrounds and docile temperaments are recommended; sex and age should be scientifically matched to experimental objectives. During pre-entry preparation, emphasis is placed on dual-credential personnel management, health surveillance, standardized disinfection of environments and cages, feed and water standards, and robust record-keeping. During reception and quarantine, standardized protocols are established for transport control, appearance inspection, isolation quarantine, pathogen exclusion, and positive-reinforcement training. During infectious experimentation, a "three-fixed" husbandry principle is clearly implemented: dedicated caretakers, fixed feeding/cleaning times, and fixed cage positions. Disinfectant selection, autoclaving of waste, and daily veterinary rounds are rigorously enforced. Operational risk control includes detailed measures for graded personal protection, animal anesthesia and restraint, zoned operation within biosafety cabinets, and disposal of experimental waste. Contingency plans are formulated to address animal death, escape, personnel exposure, and spills of infectious materials. This study provides a reproducible and scalable technical pathway and operational standard for conducting infectious experiments in laboratory cats in ABSL-2 laboratories, offering a reference for other facilities undertaking similar work.

ObjectiveTo prepare rabbit anti-porcine inhibin polypeptide-keyhole limpet hemocyanin(KLH) conjugated polyclonal antibody and evaluate its effect on superovulation in C57BL/6J mice. MethodsNew Zealand white rabbits were immunized with a synthesized porcine inhibin polypeptide conjugated with KLH to produce anti-inhibin serum (AIS, i.e., inhibin polyclonal antibody). Female C57BL/6J mice received intraperitoneal injections of purified AIS in combination with pregnant mare serum gonadotropin (PMSG), followed by human chorionic gonadotropin (hCG) after 48 hours to induce superovulation. Oocytes obtained from superovulation were collected and counted 15 hours post-hCG administration, and the number of 2-cell embryos was assessed 24 hours after in vitro fertilization. ResultsAIS prepared by immunizing New Zealand White rabbits with KLH-conjugated porcine inhibin polypeptide was subjected to titer determination by indirect ELISA, showing titers reaching 1∶ 512 000. SDS-polyacrylamide gel electrophoresis analysis of ammonium sulfate-purified AIS revealed distinct 50 kDa and 25 kDa bands corresponding to the theoretical molecular weights of IgG antibody heavy and light chains, confirming successful production of porcine inhibin polyclonal antibody. Compared with conventional superovulation methods, AIS diluted 10-fold combined with PMSG significantly increased the number of oocytes obtained from superovulation in mice (P<0.05) by approximately 1.5-fold. ConclusionPorcine inhibin polyclonal antibody, as an improved superovulation reagent, can improve superovulation efficiency in C57BL/6J mice, and shows promising prospects for future applications.

ObjectiveTo improve the accuracy of discrete element method in simulating the processing of traditional Chinese medicine（TCM） powder system under low shear conditions. MethodsIn this study， extract powders of Tongsaimai tablets and Qige granules were used as the research objects， the angle of repose（AOR） and effective angle of internal friction of the two materials were determined by AOR test method and shear cell test method. Based on the Hertz-Mindlin with JKR V2 contact model and particle scaling theory， taking the particle-particle restitution coefficient（A）， particle-particle static friction coefficient（B）， particle-particle rolling friction coefficient（C）， particle-steel restitution coefficient（D）， particle-steel static friction coefficient（E）， particle-steel rolling friction coefficient（F） and Johnson-Kendall-Roberts（JKR） surface energy（G） as test factors， the simulated contact parameters of Tongsaimai tablets extract powder were first calibrated with a single reference value using AOR as the reference value， and then the simulated contact parameters of Tongsaimai tablets extract powder as well as Qige granules extract powder were co-calibrated with AOR and effective angle of internal friction as the joint reference value， respectively. Then， Plackett-Burman design was used to screen the critical contact parameters that have a significant effect on the simulated reference value， and the steepest ascent design was used to determine the optimal range of the critical contact parameters， finally， the regression model between the critical contact parameters and the simulated reference values was established through the design of the response surface test， and the critical contact parameters were calibrated based on the regression model and the desirability function approach. ResultsThe optimal combination of discrete elemental contact parameters A-G for Tongsaimai tablets extract powder under a single reference value was 0.100， 0.718， 0.616， 0.100， 0.400， 0.250 and 0.075 J·m^-2， which was validated to have relative errors of 0.10% and -8.64% for the simulated AOR and the simulated effective angle of internal friction， respectively. And the optimal combination of discrete elemental contact parameters A-G for Tongsaimai tablets extract powder at the joint reference values was 0.100， 0.682， 0.598， 0.100， 0.521， 0.294 and 0.075 J·m^-2， which was verified to have relative errors of 0.10% and -0.18% for the simulated AOR and the simulated effective angle of internal friction， respectively. The optimal combination of discrete elemental contact parameters A-G for Qige granules extract powder at the joint reference values was 0.150， 0.370， 0.330， 0.150， 0.500， 0.500 and 0.100 J·m^-2， which was verified to have relative errors of 2.70% and -1.30% for the simulated AOR and the simulated effective angle of internal friction， respectively. Compared with the single reference value method， the joint calibration method not only increased the number of the critical contact parameters for characterizing particle-device interactions， but also was more accurate and reliable. ConclusionCompared with the results of single reference value calibration， the results obtained by the method of joint calibration of discrete element simulation contact parameters with AOR and effective angle of internal friction as the reference values are more accurate， which can provide more accurate and reliable simulation physical property data for the simulation experiments of TCM extract powder under low shear process conditions.

The literature on the characteristics, commodity grade specifications and chemical composition of Angelicae Sinensis Radix was reviewed. It was found that the main factors affecting the changes of traits and chemical composition of Angelicae Sinensis Radix included origin, altitude, climate, soil, cultivation methods, processing and processing methods and storage methods. Among them, the volatile oil types and ferulic acid content of Angelicae Sinensis Radix produced in Minxian County of Gansu Province were better than those in some non-authentic producing areas, but some component differences remained to be verified; direct seeding and film mulching cultivation could improve the yield, volatile oil and polysaccharide content of Angelicae Sinensis Radix; continuous cropping may lead to rhizosphere soil problems of Angelicae Sinensis Radix, and rotation or intercropping could be considered; drying in the shade and smoking drying could retain the oil and aroma of Angelicae Sinensis Radix; wine stir-frying method could increase the content of Z-ligustilide, but stir-frying carbon may reduce the content of ferulic acid; high temperature and high humidity storage may affect the content of ligustilide. In the future, the quality evaluation system of Angelicae Sinensis Radix should be strengthened and improved, genuine research should be strengthened, and scientific field management methods and appropriate harvesting and processing methods should be established, so as to ensure the good clinical efficacy and stable and controllable quality of Angelicae Sinensis Radix.

Objective To analyze the correlation between the number of oil chambers,the proportion of phloem at cross-section of Aucklandiae Radix and the contents of costunolide and dehydrocostuslactone,and the correlation between inulin quantity,vessel quantity and polysaccharide content in powder characteristics,so as to explore the scientific basis for Aucklandiae Radix"identifying the quality based on appearance differentiation".Methods The constant values of the microscopic features of oil chambers,inulin and vessels were determined by cross-sectional permanent slice method,chloral hydrate method and counting analysis method,and the contents of costunolide and dehydrocostuslactone as well as polysaccharide content were determined by the high-performance liquid chromatography(HPLC)and the phenol-sulfuric acid method,respectively,and the correlation in the two groups of data was analyzed by statistical methods.Results There was a significantly positive correlation between the number of oil chambers per unit area in the cross-section of Aucklandiae Radix and the number of oil chambers per unit area in the phloem and the contents of costunolide and dehydrocostuslactone;there was a significantly positive correlation between the quantity of inulin in the powder of Aucklandiae Radix and the polysaccharide content;there was no correlation between the quantity of vessels and the polysaccharide content.Conclusion This study initially established a new method and a new technology for quality evaluation of Chinese herbal medicines based on the determination of microscopic characteristic constants of Aucklandiae Radix,which can provide a new technical method for the quality control of Aucklandiae Radix.

Objective To investigate the role of ginsenoside Rh1 in regulating the changes of characteristic differential metabolites in rat models of exercise-induced fatigue by gas chromatography-mass spectrometry(GC-MS)and multidimensional statistical analysis,and to clarify the metabolic pathways,so as to provide experimental basis and theoretical support for the effective alleviation of exercise-induced fatigue through Rh1.Methods A total of 27 SPF SD rats were randomly divided into blank control group,model group,and ginsenoside Rh1 group,with 9 rats in each group.A rat exercise-induced fatigue model was established by treadmill exercise.After blood sampling,GC-MS technology,Principal Component Analysis(PCA)and Orthogonal Partial Least Squares(PLS-DA)were used for the identification and screening of differential metabolites,which were further structurally identified in KEGG and HMDB databases.MetPA database was used to construct metabolic pathways and enrich for topological analysis.Results The time to exhaustion in the ginsenoside Rh1 group was significantly longer than that in the model group.Significant differential expression of 8 metabolites(6 significantly decreased and 2 significantly increased)was found in the model group as compared to the blank control group,and 5 metabolic pathways were involved.In the ginsenoside Rh1 group,there were 3 metabolites with significant changes compared with the model group.Citric acid and fatty acid were significantly increased,α-D-glucosamine 1-phosphate was decreased,and the main pathway involved was tricarboxylic acid cycle.Conclusion Rh1 can significantly prolong the time to exhaustion and relieve exercise-induced fatigue in rats,which is closely related to the metabolic pathway of tricarboxylic acid cycle.

Objective:To evaluate the effect of nursing specialist nurses′ assistance on the ability of nursing home nurses to maintain venous catheter under the vision of combination of medical care and nursing care, providing reference for carrying out specialized nursing assistance work in grassroots hospitals.Methods:This study was an experimental study. According to Miller′s pyramid theory, a model of specialist nurse assistance was established with specialized technology as the core. From January to December 2021, three nursing hospitals in Suzhou were assisted. Convenience sampling method was used to investigate the ability of intravenous catheter maintenance, the incidence of central venous catheter maintenance defects, the incidence of central venous catheter complications and unplanned extubation, and the satisfaction of doctors and patients before and after help.Results:Totally 86 nurses were included, aged (33.17 ± 2.31) years old. After the help, the theoretical and operational skill scores of nurses in the nursing home were (89.77 ± 2.11) and (92.75 ± 1.62) points, respectively, which were significantly higher than those before the help (60.84 ± 2.71) and (79.81 ± 1.68) points, and the differences were statistically significant ( t=-84.96, -52.12, both P<0.05). Among the maintenance defects of central venous catheter in nursing homes, incomplete labeling, film wrapping, blood seepage, catheter discounting, non-standard film fixing, and incomplete information of extended care were 9.95% (21/211), 8.53% (18/211), 2.84% (6/211), 6.16% (13/211), 4.74% (10/211), 2.37% (5/211) after help, all lower than 50.57% (89/176), 43.18% (76/176), 14.20% (25/176), 25.57% (45/176), 18.18% (32/176), 11.93% (21/176) before help. The differences were statistically significant ( χ2 values were 14.00 to 77.81, all P<0.05). The incidence of medical adhesive related skin injury, catheter obstruction complications and unplanned extubation were 4.44% (4/90), 3.33% (3/90) and 2.22% (2/90), respectively, which were lower than 20.51% (16/78), 15.38% (12/78) and 11.54% (9/78) before help. The differences were statistically significant ( χ2=8.81, 6.06, 4.50, all P<0.05). Doctors′ satisfaction with nurses and patients′ satisfaction with nursing work were 96.43%(27/28) and 93.75%(45/48), respectively, both higher than 71.43%(20/28) and 72.73%(32/44) before help, and the differences were statistically significant respectively ( χ2=4.77, 5.97, both P<0.05). Conclusions:From the perspective of combination of medical care and nursing care, the maintenance and assistance of intravenous catheters by the team of intravenous therapy nurses in nursing hospitals can effectively reduce the incidence of central venous catheter complications and unplanned extubation, improve the maintenance ability of intravenous catheters of nurses in nursing hospitals, and help to improve the quality of nursing care in nursing hospitals.

Objective To explore the mechanism by which diazepam alleviates lipopolysaccharide(LPS)-induced pyroptosis and inflammation to delay the progression of pulmonary fibrosis.Methods MRC-5 cells challenged with LPS were treated with diazepam and transfected with a let-7a-5p mimic alone or co-transfected with pc-DNA-MYD88.The changes in cellular expressions of inflammatory factors were analyzed with ELISA,and the expressions of fibrosis-and pyroptosis-related proteins were detected using Western blotting.In the animal experiment,C57BL/6 mice were randomized for treatment with LPS,LPS+diazepam,LPS+diazepam+let-7a-5p mimic,LPS+diazepam+ST2825(a MYD88 inhibitor),or LPS+diazepam+let-7a-5p mimic+pc-DNA-MYD88,and pulmonary fibrosis and pulmonary expression of α-SMA were examined using Masson staining and immunofluorescence staining,respectively.Results LPS exposure of MRC-5 cells significantly downregulated let-7a-5p expression,up-regulated MYD88 expression,increased the levels of IL-4,IL-6,TGF-β and TNF-α,and enhanced the expressions of fibrosis-related proteins(Col-I,Col-III,and α-SMA)and pyroptosis-related proteins(NLRP3,caspase-1,ASC,and GSDMD-N).Diazepam treatment of LPS-stimulated cells effectively inhibited the expressions of inflammation-related factors and the fibrosis-and pyroptosis-related proteins.In C57BL/6 mice,diazepam treatment obviously alleviated LPS-induced pulmonary fibrosis and reduced and pulmonary expression of α-SMA,and these effects were further enhanced by treatment with let-7a-5p mimic or ST2825,but the effect of let-7a-5p mimic was significantly attenuated by MYD88 over-expression.Conclusion Diazepam can negatively regulate MYD88 by upregulating the expression of let-7a-5p to inhibit LPS-induced pyroptosis and inflammatory response,thereby alleviating lung fibrosis in mice.

Objective To investigate the effects of linoleic acid(LA)on the diversity and structure of intestinal flora in mice.Methods Twelve SPF grade male C57BL/6J mice at 7 weeks were randomly divided into control group(CTRL group)and linoleic acid group(LA group).One day before the linoleic acid diet was supplemented,the normal food was removed from the LA group and the mice in the LA group were fasted for one night,so that the LA diet was more acceptable to the mice in the LA group,and LA was given on the day of the experiment recording,and the feed was updated at any time to ensure that the mice could eat freely until the end of modeling.After 12 weeks of modeling,mouse feces were collected,and mixed samples were collected for every two mice feces,and then 16sRNA high-throughput sequencing was performed to analyze intestinal flora structure,Alpha and Beta diversity.Results 16sRNA high-throughput sequencing showed that LA intervention damaged the richness and diversity of intestinal flora.The results of principal component analysis showed that the composition of flora in CTRL group was different from that in LA group.At gate level,the relative abundance of Actinobacteria in LA group increased(P＜0.01).At the genus level,the relative abundance of L.Duchennei in the LA group decreased(P＜0.05),but the relative abundance of Bifidobacterium,Faecalibaculum and Erysipelotrichaceae in the LA group increased(all P＜0.01).Conclusion LA intervention could reduce the richness and diversity of intestinal flora in mice,and adjust the structure of intestinal flora.There were significant differences between beneficial bacteria and pathogenic bacte-ria in intestinal flora after LA intervention,which provided certain basis for the treatment of bioactive compounds of linoleic acid and the therapeutic adjustment of intestinal microorganisms as targets.

ObjectiveTo observe the spontaneous testicular tumors in interferon receptor-deficient mice (AG129) and provide a basis for further research using this mouse strain. MethodsThe AG129 mouse population was bred in an SPF barrier environment and reproduced normally. Among the 3-week-old weaned mice, we found that one male mouse had an abnormally enlarged testis, while none of the other mice in the same litter exhibited a similar condition. The spontaneous testicular tumor in this mouse was continuously monitored. The mouse was euthanized and dissected at 9 weeks of age. The gross morphology of the tumor was observed, and the tissue was then embedded in paraffin and sectioned for hematoxylin and eosin (HE) staining. ResultsAfter several weeks of observation, the tumor tissue gradually increased in size as the mice aged. Upon dissection, the tumor tissue was encapsulated in a smooth capsule. After opening the capsule, the tumor tissue was irregular in shape, with some areas being hard and others soft. The results of HE staining showed that the tumor tissue developed from tissues derived from multiple germ layers, with nerve tissue, bone tissue, muscle tissue, and adipose tissue inside, exhibiting an irregular morphological structure. ConclusionBased on the tumor development, gross morphological structure, and the HE staining results of the pathological sections, the tumor in this mouse was preliminarily diagnosed as an immature teratoma.