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.

【Objective】 To evaluate the safety and efficacy of modified ultrasound-guided needle-like visible nephroscope (Needle perc) holmium laser lithotripsy in the treatment of 1-2 cm calyceal calculi, and provide a reference for the selection of clinical treatment methods. 【Methods】 The clinical data of 60 patients with single intrarenal calyceal calculi (the largest diameter 1~2 cm) treated in our hospital during Jan.2022 and May 2023 were retrospectively analyzed.The patients were divided into ureteroscopic holmium laser lithotripsy group (flexible ureteroscope group) and Needle perc group, with 30 patients in either group.The clinical data of the two groups were compared. 【Results】 Compared with the flexible ureteroscope group, the Needle perc group had shorter overall hospitalization time [(3.00±1.25) d vs. (4.00±1.25) d], shorter operation time [(44.63±5.42) min vs. (48.50±7.24) min], lower hospitalization expenses [(15 518±441) yuan vs. (16 872±903) yuan], higher stone-clearance rate [93.3% (28/30) vs. 50.7% (15/30), P<0.001], less increase of procalcitonin after operation [(0.02±0.01) vs. (0.12±0.18), P=0.007], and lower incidence of complications [3.3% (1/30) vs. 26.7% (8/30), P=0.030]. 【Conclusion】 The modified ultrasound-guided Needle perc holmium laser lithotripsy is safe and effective in the treatment of 1-2 cm lower calyceal calculi, with high stone removal rate and low complication rate.

Objective:To evaluate the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on tourniquet-induced hypertension (TIH) in the patients undergoing anterior cruciate ligament reconstruction.Methods:Seventy-four patients of either sex, aged 18-60 yr, of American Society of Anesthesiologists Physical Status classification I or II, with body mass index of 18-30 kg/m 2, undergoing elective anterior cruciate ligament reconstruction under general anesthesia combined with preoperative femoral nerve block, were divided into 2 groups ( n=37 each) using a random number table method: sham stimulation group (group SS) and group taVNS. Group SS received stimulation on the ear lobe and the tail of the helix of the left ear. Group taVNS received stimulation on the cymba concha and the earlobe of the left ear. Both groups received stimulation from 1 h before induction of anesthesia until the end of the procedure (frequency of 30 Hz, pulse width of 300 μs, and amplitude of the strongest current that could be tolerated by the patient in the absence of pain). The tourniquet inflation pressure was 280 mmHg, with an inflation time of 60-90 min. Systolic blood pressure, diastolic blood pressure and heart rate were recorded before tourniquet inflation to assess the development of intraoperative TIH. The consumption of intraoperative propofol, remifentanil, nitroglycerin, esmolol, norepinephrine and atropine was recorded, and the occurrence of postoperative nausea and vomiting, skin itching and headache and dizziness was also recorded. Results:Compared with group SS, the incidence of TIH and the number of patients used nitroglycerin were significantly reduced ( P<0.05), and no significant changes were found in the other parameters in group taVNS ( P>0.05). Conclusions:taVNS can decrease the occurrence of TIH in the patients undergoing anterior cruciate ligament reconstruction.

Objective To establish and evaluate a rapid detection method for SARS-CoV-2 based on reverse transcriptase-recombinase aided amplification(RT-RAA)combined with the clustered regularly interspaced short palindromic repeats(CRISPR)/Cas12a system.Methods RT-RAA primers and CRISPR-derived RNA(crRNA)were designed based on the nucleocapsid(N)gene of SARS-CoV-2 from NCBI database.The detection system was optimized with magnesium acetate(MgAc)concentration,RT-RAA reaction tempera-ture and time and LbCas12a reaction temperature.The sensitivity and specificity of the method were evaluated using recombinant plas-mids(100-106 copies/μL)and other respiratory pathogens.The RT-RAA-CRISPR/Cas12a method was compared with RT-PCR by tes-ting 70 clinical samples in parallel.Results The optimized RT-RAA-CRISPR/Cas12a assay could detect SARS-CoV-2 within 50 min at 37 ℃.The limit of detection was 10 copies/μL for the fluorescence-based method and 1×102 copies/μL for the lateral flow assay.The method specifically detected SARS-CoV-2 without cross-reactivity to other respiratory pathogens.The results of testing 70 clinical samples using RT-RAA-CRISPR/Cas12a showed agreement of 100％with those of RT-PCR.Conclusion The established RT-RAA-CRISPR/Cas12a assay for SARS-CoV-2 detection is rapid,cost-effective,highly sensitive and specific.It can be performed by less experienced personnel and no expensive equipment is required,thus it may provide a new approach for rapid clinical diagnosis and large-scale on-site screening of SARS-CoV-2.

Platelets contribute to maintaining brain homeostasis in a physiological environment,and platelet dysfunction is closely associated with the occurrence of many diseases,including neurodegenerative diseases.This article provides a comprehensive summary of the various functions of platelets and their role in the occurrence and development of one specific neurodegenerative disease,Parkinson's disease.It discusses the correlation between platelet functional status and Parkinson's disease pathology,the potential and possible clinical significance of platelet heterogeneity as a peripheral biomarker for Parkinson's disease diagnosis and prognosis,as well as the therapeutic potential of healthy platelets in Parkinson's disease.

Objective To investigate the prevalence of single nucleotide polymorphisms (SNPs) of artemisinin resistance-related Pfubp1 and Pfap2mu genes in Plasmodium falciparum isolates from Bioko Island, Equatorial Guinea, so as to to provide baseline data for the formulation of malaria control strategies in Bioko Island. Methods A total of 184 clinical blood samples were collected from patients with P. falciparum malaria in Bioko Island, Equatorial Guinea from 2018 to 2020, and genomic DNA was extracted. The Pfubp1 and Pfap2mu gene SNPs of P. falciparum were determined using a nested PCR assay and Sanger sequencing, and the gene sequences were aligned. Results There were 159 wild-type P. falciparum isolates (88.83%) from Bioko Island, Equatorial Guinea, and 6 SNPs were identified in 20 Pfubp1-mutant P. falciparum isolates (11.17%), in which 4 non-synonymous mutations were detected, including E1516G, K1520E, D1525E, E1528D. There was only one Pfubp1gene mutation site in 19 Pfubp1-mutant P. falciparum isolates (95.00%), in which non-synonymous mutations accounted for 68.42% (13/19). D1525E and E1528D were identified as major known epidemic mutation sites in the Pfubp1 gene associated with resistance to artemisinin-based combination therapies (ACTs). At amino acid position 1525, there were 178 wild-type P. falciparum isolates (99.44%) and 1 mutant isolate (0.56%), with such a mutation site identified in blood samples in 2018, and at amino acid position 1528, there were 167 wild-type P. falciparum isolates (93.30%) and 12 mutant isolates (6.70%). The proportions of wild-type P. falciparum isolates were 95.72% (134/140), 79.25% (126/159) and 95.83% (161/168) in the target amplification fragments of the three regions in the Pfap2mu gene (Pfap2mu-inner1, Pfap2mu-inner2, Pfap2mu-inner3), respectively. There were 16 different SNPs identified in all successfully sequenced P. falciparum isolates, in which 7 non-synonymous mutations were detected, including S160N, K199T, A475V, S508G, I511M, L595F, and Y603H. There were 7 out of 43 Pfap2mu-mutant P. falciparum isolates (16.28%) that harbored only one gene mutation site, in which non-synonymous mutations accounted for 28.57% (2/7). For the known delayed clearance locus S160N associated with ACTs, there were 143 wild-type (89.94%) and 16 Pfap2mu-mutant P. falciparum isolates (10.06%). Conclusions Both Pfubp1 and Pfap2mu gene mutations were detected in P. falciparum isolates from Bioko Island, Equatorial Guinea from 2018 to 2020, with a low prevalence rate of Pfubp1 gene mutation and a high prevalence rate of Pfap2mu gene mutation. In addition, new mutation sites were identified in the Pfubp1 (E1504E and K1520E) and Pfap2mu genes (A475V and S508G).

Objective: To examine mental health problems among adolescents in Taiyuan City and its relationship to chronotype, so as to give a scientific basis for supporting mental health of middle school students. Methods: From October to November 2021, a total of 2 621 pupils were enrolled from three junior high schools and two senior high schools in Taiyuan by using a multi stage stratified cluster random sampling method to investigate demographic characteristics, mental health status, and chronotype. Chi squared test, Spearman correlation analysis and Logistic regression were used to analyze the relationship between sleep patterns and mental health problems in middle school students. Results: The proportion of morning, intermediate and evening types of middle school students sleep were 17.9%, 65.6%, and 16.4%, respectively. The overall detection rate of mental health problems was 13.8 %, which was statistically significant among middle school students in different grades, self perceived family economic status, the number of friends and sleep patterns ( χ 2=42.69, 29.15, 46.02, 93.99, P <0.05). After adjusting for grade, self perceived family economic status and the number of friends, Logistic regression analysis revealed that mental health problems were positively associated with evening type ( OR =2.84) and negatively associated with morning type ( OR =0.61)( P ＜0.05). Conclusion Chronotype is associated with mental health problems among middle school students, with a higher risk for evening type and a lower risk for morning type. Mental health of middle school students can be enhanced by changing their chronotype.

Humans ; Asthma/drug therapy* ; Biological Therapy

Background Based on numerous epidemiological studies, radionuclide ¹³¹I can result in thyroid disease. Objective To study the contamination level of thyroid ¹³¹I in ¹³¹I treatment associated radiation workers in nuclear medicine departments in Shanghai. Methods Based on a general survey on basic situation of nuclear medicine in Shanghai, the level of internal exposure of radiation workers involved in ¹³¹I treatment was assessed with questionnaires and on-site monitoring. A portable γ spectrometer was used for on-site detection, the intake and annual effective dose were estimated according to the measurement results. Physical examination reports were collected for radionuclide positive workers, and chromosome testing was performed. Results There were 579 nuclear medicine workers and 175 were engaged in ¹³¹I treatment in Shanghai. ¹³¹I was detected in thyroid of 18 workers, with a detection rate of 10.3%. Among them, the detection rates of thyroid ¹³¹I in nurses and cleaners were 23% and 25% respectively. The mean measured activity of thyroid ¹³¹I was 306.1 Bq and the maximum measured activity was 3716.9 Bq (nurse). The maximum intake was estimated at 37544 Bq and the median was 786.4 Bq. The average annual committed effective dose was 1.22 mSv and the maximum value was 14.87mSv. The chromosomal aberration rates of all detected workers were negative, and all blood indicators were normal except one with low hemoglobin. Conclusion The annual dose of nuclear medical staff engaged in ¹³¹I treatment does not exceed the national standard limit, but the internal exposure of nurses and cleaners should not be ignored. On the basis of strengthening protection and decontamination, routine internal exposure monitoring should be carried out.

Objective:To evaluate the right atrial volume and function abnormalities in patients with pulmonary hypertension (PH) by four-dimensional automatic quantitation technique, and to explore the application value of this technique in evaluating the risk stratification and World Health Organization functional class(WHO-FC) of PH patients.Methods:Eighty-four adult patients with PH diagnosed by right heart catheterization from April to October 2022 in Fuwai Central China Cardiovascular Hospital were consecutively enrolled as the PH group. All cases were divided into 3 groups according to the mean pulmonary arterial pressure (mPAP): mild PH group ( n=28), moderate PH group ( n=28), severe PH group ( n=28). Twenty-eight healthy volunteers matched by gender and age were included in the same period as the control group. The volume and strain parameters of the right atrium were obtained by analyzing the four-dimensional image of the right atrium using four-dimensional automatic quantitation technique, including right atrial minimum volume index (RAVImin), right atrial maximum volume index (RAVImax), right atrial presystolic volume index (RAVIpreA), right atrial ejection fraction (RAEF), right atrial passive ejection fraction (RAPEF), right atrial active ejection fraction, RAAEF, longitudinal strains of right atrial reserve, conduit and systolic period (RASr, RAScd, RASct), circumferential strains of right atrial reserve, conduit and systolic period (RASr-c, RAScd-c, RASct-c). The differences in right atrial parameters among four groups were compared.ROC curve was used to analyze the diagnostic efficiency of right atrial four-dimensional strain parameters for PH patients with WHO-FC≥Ⅲ. Pearson linear correlation analysis was used to investigate the relationships between RASr and right atrial area (RAA), NT-proBNP and tricuspid annular plane systolic excursion to pulmonary arterial systolic pressure ratio (TAPSE/sPAP). Results:①Compared with the control group, RAEF, RAPEF, RASr, RAScd, RASr-c, RAScd-c were significantly decreased in mild, moderate and severe PH groups; while RAAEF, RASct, RASct-c were significantly increased in mild PH group and significantly decreased in moderate and severe PH groups, and the differences were statistically significant (all P<0.05). RAVImin, RAVImax, RAVIpreA gradually increased among the control, mild PH, moderate PH and severe PH groups, and the differences were statistically significant (all P<0.05). RAEF, RAPEF, RAAEF, RASr, RAScd, RASct, RASr-c, RAScd-c, RASct-c were decreased successively among mild, moderate and severe PH groups, and the differences were statistically significant (all P<0.05). ②ROC curve showed that RASr had the highest diagnostic efficiency in PH patients with WHO-FC ≥Ⅲ, and the cut-off value was 20.5% (AUC=0.914, P<0.001). ③Correlation analysis showed that RASr was correlated with RAA, NT-proBNP and TAPSE/sPAP ( r=-0.803, -0.621, 0.739; all P<0.001). Conclusions:The degree of right atrial function impairment increased in patients with mild, moderate and severe PH in turn. RASr is the best predictor of WHO-FC ≥Ⅲ in patients with pulmonary hypertension and is a potential parameter for risk stratification in patients with PH.