[Objective] To investigate the molecular prevalence and genotype of human parvovirus B19(B19) among blood donors in Lanzhou, and provide data support for monitoring the positive rate of B19 DNA in local blood donors. [Methods] A total of 7 644 blood donor samples collected from January to September 2022 were randomly screened using real-time fluorescent PCR, resulting in 23 samples testing positive for B19 DNA. The characteristics of the B19 DNA reactive donors including gender, age, blood donation recruitment and promotion mode, and donation frequency were analyzed using SPSS 22.0. Additionally, the VP1 gene fragment of B19 DNA reactive samples was sequenced and an evolutionary tree was constructed by the N-J method. [Results] The results showed that the positive rate of B19 DNA in Lanzhou was 0.30%, and the positive population mainly consisted of female individuals aged 18-30 years old who were first-time blood donors; furthermore, genotype 1a was identified as predominant. [Conclusion] The positive rate of B19 DNA is low among blood donors in Lanzhou, with genotype 1a being predominant. It is recommended to periodically monitor the B19 prevalence in blood donors and enhance prevention and control measures, thus improving blood quality and safety.

【Objective】 To analyze the comprehensive factors causing adverse reactions to apheresis platelet donation(ARAPD), so as to provide references for effective prevention of ARAPD. 【Methods】 The 272 cases of ARAPD from 2012 to 2019 in Lanzhou were statistically analyzed, and factors that induced ARAPD were studied. Statistical analysis were performed according to the gender, nationality, occupation, age, weight, donation units, and number of donations. 【Results】 As to the factors inducing ARAPD, anticoagulant reactions accounted for the first(32.4%, 88/272). Women and students were prone to develop ARAPD. Among all age groups, 18~25 years old were most likely to develop ARAPD(53.68%, 10 572/35 265). The incidence of ARAPD were significantly different by ages and weights(P<0.05), and donors with lighter weight were more prone to develop ARAPD(P<0.05). The incidence of ARAPD were also significantly different between first-time and repeated donors(P<0.05), but not among the donation units. 【Conclusion】 The anticoagulant reactions are the leading reason for ARAPD. For female, student, young, light-weight, and first-time blood donors, special attention should be paid and corresponding interventions taken to them.

Objective To explore the effect of resilience in the relationship between workplace bullying （WPB） and professional identity among nursing interns. Methods A total of 292 nursing interns from six grade A hospitals were selected as the research subjects using convenience sampling method. The WPB，professional identity，resilience，perceived stress and coping styles were investigated by the Negative Acts Questionnaire Revised， the Professional Identity Questionnaire for nurse students，the Chinese version of 10-item Connor-Davidson Resilience Scale，the Chinese Perceived Stress Scale and the Simplified Coping Style Questionnaire. Results The scores of WPB and perceived stress were negatively correlated with those of professional identity，resilience，and positive coping styles（PCS）［Spearman correlation coefficients（rS ）were −0.354，−0.316，−0.388，−0.488，−0.636 and −0.478，all P<0.01］. There was a negative correlation between negative coping styles（NCS）and professional identity（rS =−0.117，P=0.046）. The scores of resilience and professional identity were positively correlated with that of PCS（rS were 0.539 and 0.482，both P<0.01）. There was a positive correlation between resilience and professional identity （rS =0.567，P<0.01）. The scores of WPB and perceived stress were positively correlated with that of NCS（rS were 0.350 and 0.281，both P<0.01）. There was a positive correlation between WPB and perceived stress（rS =0.419，P<0.01）. The scores of resilience and PCS were not correlated with that of NCS（both P>0.05）. Resilience played a mediating role between WPB and professional identity. The interaction between WPB and NCS could predict the professional identity and resilience of nursing interns（standardized regression coefficient were 0.31 and 0.17，both P<0.01）. Conclusion WPB can directly or indirectly affect nursing interns’professional identity through resilience，and NCS plays a moderating role on the direct effect of WPB and professional identity，and the relationship between WPB and resilience.

Objective:To evaluate the efficacy and safety of radiofrequency introduction of L-vitamin C in patients with melasma.Methods:From March to June 2019, 20 patients with melasma were admitted to the Department of Dermatology, the Seventh Medical Center of PLA General Hospital, including 19 females and 1 male, aged 30-60 years, with an average age of 43.5 years. All patients were treated with 22 percent of L-vitamin C once a week, a total of 8 times of treatment and followed up for 12 weeks. Each subject was assessed with standardized clinical photo, skin tests (VISIA skin image analyzer and CK multifunctional skin tester) and patient self-assessment. In addition, the adverse reactions were recorded.Results:Physician evaluation and patient self-evaluation showed that skin symptoms were improved obviously after treatment. 90% of the subjects thought that all of the skin moisture, pores, fine lines, glossiness, and color spots were improved after 12 weeks. The skin texture, ultraviolet stain and the brown spots which were detected with VISIA skin image analyzer were all improved after one week and one month. Difference was statistically significant ( P<0.05). Skin glossiness was significantly improved, skin moisture content increased and melanin decreased, which were detected with CK multifunctional skin tester. The differences were statistically significant ( P<0.05). But there was no significant change in transdermal water loss and red pigment index ( P>0.05). Conclusions:22% L-vitamin C can be used to treat melasma and improve photoaging safely without affecting skin barrier function.

【Objective】 To evaluate the anti-HCV detection ability of our laboratory, and explore the factors that may affect anti-HCV detection, so as to provide data and basis for the evaluation of laboratory ability. 【Methods】 The number of initial reactive (IR) and repeated reactive(RR)samples and the reagent utilization rate in anti-HCV from 2019 to 2020 were compared with the national reagents of the same group. 【Results】 1)The average unqualified rate of anti-HCV detection was 0.25%, with the lowest rate at 0.19%, 33/17 774, and the highest rate at 0.37%, 44/11 940; 2)The retest rates of reagent 1 and reagent 2 were significantly different (P < 0.05); 3)The RR/IR rates of reagent 1 and reagent 2 showed no significant difference (P> 0.05), while the RR/IR rates of reagent 1 and reagent 2 showed a slow upward trend; 4)The solo reagent unqualified rate of reagent 1 and reagent 2 showed statistically significant difference (P < 0.05); 5)The reagent utilization rate was basically the same as the national average level of reagents in the same group. 【Conclusion】 The anti-HCV detection indicators of our laboratory are relatively stable, but other factors such as personnel training, equipment performance and environment also have an impact on the detection ability of laboratories. Fine management of various element should be carried out, and external quality assessment reports of blood testing laboratory should be analyzed to further improve the anti-HCV detection ability of the laboratory.

Objective To investigate the distribution of β-lactamase genes in a pan-drug resistant Klebsiella pneumoniae isolate JM45.Methods Klebsiella pneumoniae JM45 was isolated from the blood sample of a patient admitted in the intensive care unit,the Second Affiliated Hospital,Zhejiang University School of Medicine on April 7,2010.The susceptibilities to 26 antibiotics were tested using E-test method.Cica-β-Test was performed to detect β-lactams,and modified Hodge test was performed to detect carbapenemase.Resistant genotypes were detected using PCR,DNA sequencing and BLAST algorithm.Whole genome sequencing (complete graph) was performed by high throughput Roche 454 sequencing approach to analyze the distribution of β-lactamase genes.Results Except polymyxin B and tigecycline,JM45 was resistant to other 24 kinds of antibiotics including cephalosporins and carbapenems.Several β-lactamases were positive in Cica-β-Test,and modified Hodge test was positive.Based on PCR typing,TEM-1,SHV-11,CTX-M-24 and VEB-3 were positive,but carbapenemase genes and metallo-β-lactamase genes were negative.A complete genome (chromosome) sequence (GenBank accession number:CP006656) and 2 plasmids sequences (GenBank accession number:CP006657,CP006658) were obtained by wholegenome sequencing.CTX-M-24 (Locus tag:N559_5233),TEM-1 (Locus tag:N559_5242) and VEB-3 (Locus tag:N559_5248) were positive in plasmid 1.CTX-M-24 located in insertion sequence (IS903-CTXM-24-ISEcp1),while TEM-1 and VEB-3 located in transposons (tnpA-TEM-1-rmtB and VEB-3-tnpA).SHV-11 (Locus tag:N559_2715) was positive in genome (chromosome),and 4 putative β-lactamase genes or β-lactamase domains were obtained:(1) metallo-β-lactamase domain protein (Locus tag:N559_0119,780 bp) ; (2) putative β-lactamase (Locus tag:N559_1633,1308 bp) ; (3) β-lactamase domain protein (Locus tag:N559_2279,813 bp); (4) β-lactamase domain protein (Locus tag:N559_3769,1101 bp).No insertion sequence or transposase gene was observed near SHV-11.Conclusion The resistance to antibiotics including cephalosporins and carbapenems is correlated with TEM-1,SHV-11,CTX-M-24,VEB-3 and 4 kinds of putative β-lactamase genes or β-lactamase domains.

Objective To explore the influence of drug dosage, solvent and other main influencing factors on the successful establishment of alloxan-induced hyperglycemia mouse model and the effect on the stability of this model. Methods 160 6-8-week-old Kunming mice ofSPF grade, (male:female=1:1) were used in this study.The influences of different dosages of alloxan and solvent combinations on the successful establishment rate of the model, survival rate, body weight, fasting blood glucose, blood glucose area under curve, serum insulin level and their stabilities were dynamically observed for six weeks.Results By single intraperitoneal injection of 160 mg/kg bw alloxan ( pH 4.5 citrate sodium as solvent) , we were able to obtain a stable experimental hyperglycemic mouse model with higher levels of successful establishment rate (70%), survival rate (75%), fasting blood glucose (15-20 mmol/L), glucose area under the curve (55-65 mmol/L) and a lower but not loss of serum insulin levels (21 mIU/L).Conclusions In the present study we have carefully considered the influence of main factors such as drug dosages, solvent, etc., on the alloxan-induced experimental hyperglycemic mouse model, and successfully established this model after 6-week period observation of its stability.This model may provide a useful tool in the research of experimental diabetes and hypoglycemic functional studies.

Objective To analyze molecular evolution of carbapenemase KPC-12 and its binding free energies with β-lactams.Methods Class A beta-lactamases were divided into 2 clusters:those with carbapenemase activities and those without.Minimum Evolution method in MEGA4.1 software was used to analyze molecular evolution of class A beta-lactamases with carbapenemase activity,including KPC-2 to KPC-13,SFC-1,SME-1,IMI-1,NMC-A,and class A beta-lactamases without carbapenemase activity,including TEM-1,SHV-1.Then,tertiary structure of KPC-12 was predicted by homology modeling as reported in SWISS-MODEL database depending on tertiary structure of KPC-2.Moreover,DOCK module in ArgusLab 4.1 software was used to perform molecular docking of KPC-12 to 10 kinds of beta-lactams substrates,and the binding free energies (△ G) were calculated.Results Molecular evolution between KPC-12 and KPC-2 was the closest.The top three decline in binding free energies of β-lactams were penicillin G sodium salt (△G =-8.45149 kcal/mol),ertapenem (△G =-8.36383 kcal/mol) and ampicillin (△G =-8.19326 kcal/mol),while the last two decline in binding free energies of β-lactams were aztreonam (△G =-6.50614 kca]/mol) and clavulanic acid (△G =-6.88533 kcal/mol).Conclusion Carbapenemase KPC-12 has high catalytic activities to penicillin G sodium salt,ertapenem and ampicillin,while has low catalytic activities to aztreonam and clavulanic acid.

Objective To evaluate the killing efficacy of chlorine-releasing agents (CRAs) with different concentrations on multidrug-resistant Acinetobacter baumannii.Methods Totally 30 clinical strains of multidrug-resistant Acinetobacter baumannii were collected from November 2008 to December 2009.Killing efficacy of CRAs on these strains was evaluated by quantitative suspension test.The one-way analysis of variance was performed.Results The log values of killing to 30 strains of multidrug-resistant Acinetobacter baumannii were all ≥5.00,when the bacteria were exposed to available chlorine concentrations 400 mg/L of CRAs for 10 min,600 mg/L for 10 min,800 mg/L for 3 min and 1000 mg/L for 1 min,respectively.And effective rates were all 100％. Furthermore,there were significant differences among different available chlorine concentrations exposed for the same time ( except 10 min) ( F =72.72,64.79 and 32.33,P =0.00),and among different exposure time in the same available chlorine concentration ( except 1000 mg/L) ( F =110.42,20.41 and 3.20,P=0.00,0.00 and 0.03).Conclusion Satisfactory killing efficacy of CRAs to multidrug-resistant Acinetobacter baumannii can be achieved with available chlorine concentration 500 mg/L to 1000 mg/L and exposure time 10 min to 30 min.

ObjectiveTo investigate correlation between drug-resistance related genes and mobile genetic elements of Klebsiella pneumoniae resistant to β-lactams. Methods Forty-seven strains of multidrug-resistant Klebsiella pneumoniae were collected from 6 hospitals in Hangzhou and Huzhou of Zhejiang province from August 2008 to May 2010.Modified Hodge test was performed to detect phenotypes of carbapenemases.Forty kinds of β-lactamases (class A-D),ompK35,ompK36,and 12 kinds of mobile genetic elements were detected by PCR,and the results were analyzed by index cluster.ResultsThirty-five strains were positive in modified Hodge test,and 5 kinds of β-lactamases gene ( including KPC-2-like,GenBank:HQ258934) and 9 kinds of mobile genetic elements were detected.Mutations were observed in ompK35 and ompK36 when compared with sensitive strains.Index cluster analysis showed that correlation existed between KPC-2,KPC-2-like and ISKpn6,between TEM-1 and ISEcpl,IS26,int Ⅰ 1,trbC,IS903,and between CMY-2,OXA-30,DHA-1 and tnpU,tnp513,trbC.ConclusionsFive kinds of β-1actamases genes,and mutations in ompK35 and ompK36 may be associated with the resistance to β-1actams in multidrug-resistant Klebsiella pneumoniae.