Abstract: Objective　To determine the rate of nasal carriage Staphylococcus aureus among healthcare workers in Department of Infectious Diseases department of the First Affiliated Hospital of Xi'an Jiaotong University Hospital, and to perform characterization on isolated strains. Methods　A cross-sectional study was performed on 86 healthcare workers from February 2022 to June. Nasal swabs were collected from the healthcare workers, and S. aureus were identified after incubation. Antibiotic susceptibility, including chlorhexidine and mupirocin, was assessed by disk diffusion and minimal inhibitory concentration method. The PCR technique was used to detect the biocide resistance genes (qacAB, smr, lmrS mepA, and sepA), virulence genes (pvl, fnbA/fnbB, sea, seb, sec, sed, tst, eta, etb) and mecA gene. SCCmec typing and multilocus sequence typing was performed. For mupirocin-resistant strains, PCR amplification and sequencing were used to identify whether the strains had ileS gene mutations or carried resistant genes (mupA and mupB). Results　S. aureus was isolated from 37 of the 86 healthcare workers (43.02%) , including 13 methicillin-resistant Staphylococcus aureus (MRSA) strains. The strains showed low resistance rates to levofloxacin (2.70%, 1/37), chloramphenicol (8.11%, 3/37), tetracycline (8.11%, 3/37), gentamicin (10.81%, 4/37), and ciprofloxacin (10.81%, 4/37). A total of 17 strains were identified as multidrug-resistant strains. Four SCCmec types were identified in MRSA strains, with the type II being the most frequent (53.85%, 7/13), followed by type IV (30.77%, 4/13). ST59 (46.15%, 6/13) was the most frequent among MRSA strains, while ST5 (41.67%, 10/24) was the most frequent among methicillin-susceptible S. aureus (MSSA) strains. sea was the most frequent virulence gene (56.76%, 21/37). sepA and mepA were detected in all 37 isolates. One Staphylococcus aureus strain was not sensitive to chlorhexidine, two strains had the missense mutation V588F (G1762T) and showed low level resistance to mupirocin, and one strain carrying mupA gene was highly resistant to mupirocin. Conclusion　The nasal colonization rate of Staphylococcus aureus among healthcare worker in the investigated hospital was high, indicating a risk for nosocomial infections. Strengthened monitoring and decolonization treatment should be carried out to reduce these risks.

Air Pollutants, Occupational ; analysis ; Gas Chromatography-Mass Spectrometry ; methods ; Volatile Organic Compounds ; analysis ; Workplace

Animals ; Drugs, Chinese Herbal ; therapeutic use ; Humans ; In Vitro Techniques ; Mice ; Myocarditis ; drug therapy ; virology ; Phytotherapy ; methods ; Virus Diseases ; drug therapy

OBJECTIVE: To study the photostability of the levofloxacin hydrochloride injection. METHODS: The content of levofloxacin hydrochloride was determined and its UV spectra changes were observed after being lighted by three different light sources-the UV light, the sunlight and the natural light for different periods of time. Whether there is any decomposed product or not was determined by TLC. RESULTS: There were decompositions of levofloxacin hydrochloride injection subjected to illumination from three light resources, with that under the sunlight decomposed faster; Rf value under TLC of the decomposed product was found to be 0.72. CONCLUSION: Levofloxacin hydrochloride injection should be kept away from UV light, the sunlight and the natural light.

4.0 cm~2),slight group(2.5-4.0 cm~2),moderate group(1.5-2.5 cm~2)and severe group(

OBJECTIVETo investigate the influence of seasons, blood types and semen parameters on the cryosurvival rate of frozen-thawed spermatozoa from sperm donors.

METHODSWe retrospectively analyzed the influence of seasons, blood types, abstinence period, semen volume, sperm morphology, and pre-freeze sperm motility and concentration on the cryosurvival rate of frozen-thawed sperm in 4 088 semen samples from Shaanxi Human Sperm Bank.

RESULTSThe cryosurvival rate of the post-thaw sperm was correlated negatively with the progressive motility of the pre-freeze sperm (r = -0.262, P < 0.01), but positively with pre-freeze sperm concentration (r = 0.247, P < 0.01), and it was significantly higher in the 6-day abstinence group ([70.2 +/- 5.4]%) than in the other abstinence groups (P < 0.01), so was it in the normal sperm morphology rate > 20% group ([71.4 +/- 5.1]%) than in the others (P < 0.01). The survival rate of the post-thaw sperm was not correlated with seasons, blood types, and semen volume (P > 0.05).

CONCLUSIONSperm motility, concentration and morphology and the abstinence period of sperm donors may be valuable predictors of the cryosurvival rate of post-thaw sperm, but no correlation was found between the survival rate and seasons, blood types and semen volume.

Objective To explore an effective method in reconstructing of burn scar contracture of the chin and neck in children. Methods The blood in the transverse cervical artery might flow reverse into the suprascapular artery and the posterior intercostals perforators through anastomic branches. An axial skin flap in the cervico-scapulo-dorsal area could be adequately supplied by this artery, and we had therefore used this flap to repair burn scar in the neck. Results 30 cases obtained satisfactory clinical results with this flap. The follow-up for two years in 18 patients showed that the neck of the patients moved about freely, and the develpment of the chin was not influenced, and the color of flaps was fine. Conclusion The blood supply of the flap is reliable and stable. So it is a very useful method in reconstructing the burn scar of the chin-neck in children.

ObjectiveTo evaluate the effectiveness of transcatheter Amplatzer device closure on patent ductus arteriosus(PDA),and to give some evidences for the clinical application.MethodsAll studies in the world regard to the controlled trials(CT) about transcatheter Amplatzer device closure and cardiac surgery on PDA were searched and made synthetic evaluation by means of Meta-analysis.RevMan 4.2.2 software was used for statistical analysis.Cases relative risk(RR)and its 95% confidence interval(CI)of procedure failure,the incidence of complication and residual shunt were calculated.ResultsTotally 5 studies including 349 cases were analyzed.Operation failure of Amplatzer device occlusion was higher than cardiac surgery [5 CT,349 cases,3.0% vs 0,RR=4.29,95%CI(0.77,23.95)](P=0.10).Incidence of complication of Amplatzer device occlusion was lower than cardiac surgery[5 CT,343 cases,3.1% vs 38.0%,RR=0.11,95%CI(0.05,0.23)](P

The influence of separating effect of different chromatographic conditions of mouse gut flora by high performance ion exchange chromatography analysis was studied. The optimum chromatographic conditions for separating gut bacteria were determined. The sample was applied to the chromatography column packed with Toyopearl SuperQ-650c anion resin, equilibrated with 0.02mol/L piperazin-hydrochloric acid buffer (pH 8.0), and elution salt 1mol/L NaCl, eluted with the gradient of 0-50% NaCl/ 80 min, then 50%~75% NaCl/ 25 min at the flow rate 1ml/min, and injecting volume was 1ml.Under these conditions, intestinal flora were separated into several fractions. The establishment of HPLC analysis method will lay a foundation of further research on the components of mouse gut flora and their dynamic changes.

CD38 is a multifunctional enzyme expressed in a variety of mammalian tissues, its catalytic activity was involved in a wide range of physiological processes. Based on the reported inhibitor of human CD38 NADase, 33 purine derivatives were designed and synthesized. The biological activity assay showed that compounds 20 and 38 exhibited almost the same extent of inhibitory activities on human CD38 NADase as the lead compound H2. The results also revealed that small substituents at C-6 of purine ring gave no obvious effect on inhibitory activity, but phenylpropionyl moiety at N-2 could affect the binding mode of the compound with CD38. This study provides a reliable basis for future rational design of inhibitors for CD38.
ADP-ribosyl Cyclase 1 ; antagonists & inhibitors ; Enzyme Inhibitors ; chemical synthesis ; chemistry ; Humans ; Purines ; chemical synthesis ; chemistry