Staphylococcus aureus is a Gram-positive bacterium with strong pathogenicity. With the widespread use of antibiotics， its multi-drug resistance has gradually increased. Among them， methicillin-resistant S. aureus （MRSA） is one of the main pathogens of hospital and community infections. Antimicrobial peptides are short-chain peptides with good antibacterial effects and low drug resistance， which have been widely studied in recent years. This study summarizes the mechanism of action of antimicrobial peptides and related study on antimicrobial peptides against MRSA from different sources. It is found that the mechanisms of action of antimicrobial peptides include targeting bacterial cell membranes， bacterial cells， and bacterial cell walls， etc. Besides isolating antimicrobial peptides with anti-MRSA activity from animals， plants， and microorganisms， antimicrobial peptides can also be obtained through synthetic methods. Among them， GHa-derived peptides from animal sources， Ib-AMP4 from plant sources， Ph-SA from microbial sources， the synthetic peptide LLKLLLKLL-NH2， and so on， due to their effective antibacterial activity， rapid bactericidal speed， and low toxicity， are promising candidates for anti-MRSA drugs.

As a traditional nutritional and healthy cash crop in China, tea has certain significance in promoting human health and preventing and controlling chronic diseases. Studies have shown that the nutritional health effect of tea is due to its rich functional components, mainly including tea polyphenols, tea pigments, tea polysaccharides, theanine, alkaloids and other bioactive substances. At present, researchers from the academic circles have continuously carried out animal and human experiments on the health effects of various functional components of tea, which has accumulated abundant research data and materials. Based on this, this article reviews the literature on the nutritional and health effects of the main functional components of tea, and adopts the method of evidence-based research to screen and extract relevant data for qualitative and quantitative meta-analysis. Subsequently, the nutritional health effects of the five functional components of tea, namely tea polyphenols, tea pigments, tea polysaccharides, theanine, and alkaloids, are summarized and outlined. Studies have shown that tea polyphenols, tea pigments, tea polysaccharides, theanine and alkaloids have different health effects and are expected to play their unique roles in promoting human health and preventing and controlling diseases.

ObjectiveTo explore the effects of the Tai Chi training on bone density， bone turnover markers， and heart rate variability for people with high-risk osteoporosis， and to provide evidence for the prevention of osteoporosis at early stage. MethodsSixty-six cases of people with high risk of osteoporosis were included， and they were divided into 33 cases each in the intervention group and the control group using the random number table method. The control group received osteoporosis health education three times a week， and the intervention group received Tai Chi training under the guidance of a trainer three times a week for 40 mins each time on the basis of the control group， and both groups were intervened for 12 weeks. Dual-energy X-ray absorptiometry was used to measure the bone density of L₁~L₄ vertebrae， bilateral femoral necks and bilateral total hips in the two groups before and after the intervention； enzyme-linked immunosorbent assay was used to determine bone turnover markers before and after the intervention， including pro-collagen type Ⅰ pro-amino-terminal prepropyl peptide （P1NP） and β-collagen type Ⅰ cross-linking carboxy-terminal peptide （β-CTX）. Seven cases with good compliance in the intervention group were selected. After wearing the heart rate sensor， they successively performed Tai Chi training and walking activities recommended by the guideline for 20 mins each， and the heart rate variability （HRV） during exercise was collected， including time-domain indexes such as standard deviation of normal sinus intervals （SDNN）， root-mean-square of the difference between adjacent RR intervals （RMSSD）， frequency-domain metrics such as low-frequency power （LF）， high-frequency power （HF）， and low-frequency/high-frequency power ratio （LF/HF）， as well as nonlinear metrics such as approximate entropy （ApEn）， sample entropy （SampEn）. ResultsFinally， 63 cases were included in the outcome analysis， including 30 cases in the intervention group and 33 cases in the control group. After the intervention， the differences of L₁~L₄ vertebrae， bone density of bilateral femoral neck and bilateral total hip in the intervention group were not statistically significant when compared with those before intervention （P＞0.05）， while the bone density of all parts of the control group decreased significantly compared with that before intervention （P＜0.05）， and the difference in the bone density of the L₁~L₄ vertebrae， bilateral femoral neck， and the right total hip before and after the intervention of the intervention group was smaller than that of the control group （P＜0.05）. The differences in P1NP and β-CTX between groups before and after intervention was not statistically significant （P＞0.05）. Compared with walking exercise， LF decreased， HF increased and LF/HF decreased during Tai Chi exercise （P＜0.05）； the time domain indexes and non-linear indexes between groups had no statistically significant difference （P＞0.05）. ConclusionTai Chi exercise can maintain lumbar， hip， and femoral bone density and improve sympathetic/parasympathetic balance in people at high risk for osteoporosis， but cannot significantly improve bone turnover markers.

Objective To investigate the effect of compound betamethasone adjuvant on break-through pain after unicompartmental knee arthroplasty under sciatic nerve combined with femoral nerve block.Methods A total of 100 patients underwent unicondylar knee arthroplasty,32 males and 68 females,aged 55-75 years,BMI 18.5-35.0 kg/m2,ASA physical status Ⅰ-Ⅲ,were divided into three groups according to random number table method:no adjuvant group(group C,n=34),dexamethasone adjuvant group(group D,n=33)and compound betamethasone adjuvant group(group B,n=33).The patients in the three groups received sciatic nerve block and 0.4％ropivacaine 15 ml before anesthesia in-duction,then femoral nerve block,0.4％ropivacaine 15 ml in group C,0.4％ropivacaine 15 ml in group D(containing dexamethasone 5 mg),and 0.4％ropivacaine 15 ml in group B(containing compound beca-methasone 4 mg).The occurrence of breakthrough pain,the number of effective analgesic pump compres-sions,opioid dosage,and the number of remedial analgesia cases were recorded.The ground movement dis-tance was recorded 0-24 hours,24-48 hours,and 48-72 hours after operation.The sleep quality scores and adverse events were also recorded.Results Compared with group C,the incidence rate of breakthrough pain was lower(P＜0.05),the number of effective analgesia pump compressions,the dosage of opioid,and the sleep quality score on the first night after operation were significantly decreased in group B(P＜0.05).Compared with group D,the incidence rate of breakthrough pain and breakthrough pain score were lower(P＜0.05),the number of effective analgesia pump compressions,the dosage of opioid,and the sleep quality score on the 1 st night after operation were significantly decreased in group B(P＜0.05).There was no significant difference in the ground movement distance of in different time periods and inci-dence of adverse events among the three groups.Conclusion Compound betamethasone adjuvant can reduce the incidence of breakthrough pain after unicompartmental knee arthroplasty under sciatic nerve com-bined with femoral nerve block,provide perfect analgesic effect,reduce postoperative opioid consumption,and improve the sleep quality of patients on the first night after surgery.

Objective To study the effects of antibiotics and high-fat diet on energy metabolism and the browning of white adipose tissue (WAT) and brown adipose tissue (BAT) in mice, so as to provide new ideas for the possible mechanism of adipose tissue in the prevention and treatment of obesity. Methods A total of 80 10-week-old C57BL/6 male mice were fed with normal diet in the early stage, and the antibiotic gavage group (AG) and antibiotic high-fat group (AFG) were given mixed antibiotics by gavage. The blank group (BG) and the high-fat diet group (FG) were given normal saline intragastric solution for 2 weeks, and after the gavage operation, the FG group and the AFG group were given high-fat diet for obesity modeling, and the BG group and AG group continued to be fed with normal diet for 8 weeks (N=20). After the experiment, each group was injected with β3-adrenergic receptor agonists for 5 days, and the high-fat/ordinary diet remained unchanged. At the end of the experiment, basal metabolic rate (BMR), fasting blood glucose (FBG) and rectal temperature were measured, and feces, blood, subcutaneous white fat, epididymis and brown adipose tissue in the scapular area of mice were collected. The automatic biochemical analyzer was used to determine the blood biochemical indexes; reverse transcription polymerase chain reaction (RT-qPCR) was used to measure the expression of genes related to browning of WAT and BAT adipose tissue, respectively. Real-time quantitative polymerase chain reaction (qPCR) was used to determine the expression of WAT mitochondrial DNA (mt DNA). Results From the 4th week to the end of the experiment, the weight of the AFG group was significantly higher than that of the AG group and significantly lower than that of the FG group (P<0.05). The body weight, organ coefficient, serum TC level, rectal temperature and WAT cell diameter in the AFG group were significantly higher than those in the AG group. The serum levels of FBG, TC and LDL in the AFG group were significantly lower than those in the FG group (P<0.05). The overall BMR(mlO2/h) FG group was significantly higher than that of BG group, and the AFG group was significantly higher than that of AG. BMR per unit body weight (mlO2/h/g) AFG was significantly higher than that of FG group (P<0.05). The expressions of RIP140, PPAR-γ and UCP-1 in BAT in the AFG group were significantly higher than those in the FG group, and the mt DNA copy number of WAT in the AFG group was significantly higher than that in the FG group (P<0.05). Conclusion Antibiotic intervention can up-regulate the expression of brown fat-related genes in high-fat diet mice, increase brown fat activity, increase the relative mitochondrial number of white fat, increase the level of browning of white fat, promote thermogenesis, increase the BMR per unit body weight of adult obese mice, and then improve the overall energy metabolism of the body, and slow down the weight gain induced by high-fat diet to a certain extent.

Objective To make a comprehensive analysis of the index of benefit and medical service ability of disease,and provide references for the operation management of public hospital based on disease.Methods TOPSIS was used to compre-hensively evaluate the income contribution,income structure,daily income,the proportion of operation/grade 4 operation,DRG-CMI and other indexes.According to the Boston matrix,two-dimensional quadrant analysis was carried out to determine the dominant diseases in the operation management.Results Twelve main diseases in a hospital specialty were analyzed,and the comprehensive scores of two dimensions of benefit and medical service ability were formed.According to the scores,a two-dimen-sional quadrant map was drawn,and the characteristics of diseases in each quadrant were summarized to identify the dominant diseases that contribute greatly to the economic operation and technical difficulty evaluation of the specialty.Conclusion The combined application of TOPSIS and Boston matrix in specialty operation analysis can help public hospital to realize the classifica-tion management of disease balancing benefit and difficulty,so as to optimize the disease structure and improve the utilization rate of medical resources.

Objective To study the inhibitory effect and related mechanisms of Qiangxin Capsule on fi-brosis caused by Wnt(wingless)/β-catenin signaling pathway in Sprague Dawley(SD)heart failure(HF)rats.Methods Fifteen SPF-grade SD male rats aged 6-8 weeks were selected as the research subjects.The rats were randomly divided into the sham operation group,model group and medication group,5 cases in each group.The model group and medication group caused abdominal aorta partial stenosis by operation.The rats in the sham operation group and model group were gavaged by 10 mL/kg of normal saline,the rats in the medication group were gavaged by 0.8 g/kg Qiangxin Capsule,and each group was continuously administered for 20 weeks.The ventricular wall motion amplitude was used to detect the left ventricular ventricular ejection fraction(LVEF),left ventricular end-systolic diameter(LVEDs)and left ventricular end-diastolic diameter(LVEDd)in each group.After 20 weeks,the rats in each group were executed,the rat myocardial tissues were taken for conducting the pathological analysis,the myocardial tissues were observed by hematoxylin-eosin(HE)staining,the fibrous tissues were observed by the Masson staining,and the protein expression levels of Wnt,β-catenin,collagen Ⅰ and collagen Ⅲ were detected by Western blot.Results LVEF in the medication group was higher than that in the model group,LVEDd and LVEDs were smaller than those in the model group,and the differences were statistically significant(P＜0.05).Compared with the model group,the Wnt/GAPDH and β-catenin/GAPDH levels in the medication group were decreased,and the difference was statisti-cally significant(P＜0.05).Compared with the model group,the collagen Ⅰ/GAPDH and collagen Ⅲ/GAP-DH in the medication group were decreased,and the difference was statistically significant(P＜0.05).Conclu-sion Qiangxin Capsule could alleviate the cardiac fibrosis degree in SD rats with heart failure after abdominal aortal coarctation,and its mechanism may be related to the inhibition of Wnt/β-catenin signaling pathway.

Objective To evaluate the quality of ultrafine powder of Spatholobus suberectus from different sources by combined HPLC fingerprint and chemical pattern recognition.Methods Separation was performed on a Amethyst C18-H column(4.6 mmx250 mm,5 pm)and the mobile phase was 0.1％phosphoric acid-acetonitrile with gradient elution.The flow rate was 1.0 mL/min and the wavelength was 260 nm.The column temperature was 30 ℃.The cluster analysis(CA),least partial squares-discriminant analysis(PLS-DA)and principal component analysis(PCA)were applied to studying the HPLC fingerprint and chemical pattern recognition.Results Thirteen common peaks were identified in ultrafine powder samples of 10 batches of Spatholobus suberectus and 3 components were identified by reference substances.The similarity of fingerprint was 0.921-0.989,indicating good similarity.The samples were divided into 3 groups by cluster analysis;principal component analysis results extracted 4 principal components.According to the composite score,the quality of ultrafine powder samples of Spatholobus suberectus from S6,S1,S2,S3 were better than others.And 4 kinds of marker compounds that caused the quality difference of ultrafine powder samples of Spatholobus suberectu were screened out through the least partial squares-discriminant analysis,which were epicatechin and peaks 1,6 and 4 respectively.Conclusion The fingerprint method is simple and reproducible,and can be used to evaluate the quality of ultrafine powder samples of Spatholobus suberectus in combination with multi-mode stoichiometric analysis.

Objective To meet the treatment requirements for mitral regurgitation disease,this study designed a novel valve repair system and evaluated its hydrodynamic performance.Methods A mitral regurgitation model was created.The valve repair system was loaded onto the regurgitation model,and pulsatile flow tests and steady backflow leakage tests were conducted.Results The pulsatile flow test results indicated that the percentage of reflux after product implantation was lower than that before implantation under different concentric outputs and reverse pressures.The average cross-valve pressure difference after implantation was less than 5 mmHg.The steady backflow leakage test results showed that as the reverse pressure increased,the leakage amount of the valve repair system after implantation also increased.Conclusion The developed valve repair system exhibits excellent hydrodynamic performance,suggesting the feasibility of its application in the treatment of clinical mitral regurgitation.

In order to understand the characteristics of avian leukosis virus(ALV)infection and the polymorphisms of receptor genes Tva,Tvb and NHE1 sequences in different Qingyuan Ma chick-en breeding farms,the isolation and identification of exogenous ALV virus,receptor gene amplifi-cation and sequencing analysis were carried out in five Qingyuan Ma chicken breeding farms.The results of virus isolation and subtype identification showed that the positive rate of exogenous ALV virus isolation in farms A,B and C was less than 5％,among which there was ALV-J infection alone in farm A,mixed infection with ALV-J and ALV-K in farm B,ALV-K infection a-lone in farm C,and no exogenous ALV infection was detected in farm D and E.Polymorphism anal-ysis of recipient genes showed that there were different frequencies of Tvar3,Tvar4 and Tvbr3 re-sistance alleles in A-E farms,and the distribution frequency of Tvar3 was 0.2-0.6,the distribution frequency of Tvar4 was 0.3-0.7,and the distribution frequency of Tvbr3 was 0.1-0.7.In addition,there were Tvar5 resistance alleles in both B and D farms,with a distribution frequency of 0.2.A to-tal of 18 SNP mutations occurred in the NHE1 receptor gene sequence,and further analysis showed that positions 1 279,1 361,1 369,1 406,1 442,and 1 912 were non-synonymous mutations,which could cause changes in amino acids.The study suggested that there were differences in the exogenous ALV and its subtypes among the five Qingyuan Ma chicken breeders,and each farm should have a more targeted and unique purification strategy.The distribution of Tva and Tvb re-sistance alleles at different frequencies,along with the occurrence of 6 non-synonymous mutations in the NHE1 gene,indicate that Qingyuan Ma chicken have the potential of genetic resistance breeding.