Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

Lung cancer is the most common malignant tumor and the second most common malignant tumor in terms of mortality in the world.Non-small cell lung cancer(NSCLC)is the most common pathological type of lung cancer.Currently,the first-line standard treatment for advanced NSCLC is immunotherapy and targeted therapy.Although these treat-ments prolong the survival of patients,acquired drug resistance is still inevitable.Antibody-drug conjugates(ADCs)are a new type of anti-tumor drug made by coupling cytotoxic payloads to specific monoclonal antibodies via linkers.Compared with chemotherapy drugs,ADCs have the advantages of accurate recognition,local release,and high patient tolerance.In recent years,they have shown good clinical benefits in the treatment of NSCLC.This article provides an overview of the mechanism of action of ADCs,clinical studies progress in advanced NSCLC,and existing problems and challenges.

Objective To explore the effects of different types of drinking water on the growth and fecal flora of mice.Methods Specific pathogen-free NIH mice were randomly divided into five groups,32 mice each group,with half males and half females in each group.The group were given either purified water(control group),acidified water,alkalized water,weakly acidic water or solid water.Diet and body weight were monitored continuously for 20 days.After the experiment,animal fecal samples were collected,and the V3-V4 region was amplified with bacterial 16S rDNA universal primers.An Illumina Miseq high-throughput sequencing platform was used for high-throughput sequencing,and microbial community,α diversity and β diversity were analyzed by bioinformatics method.Results The body weight of female mice given different pH values of weakly acidic water was higher,while the weight of the other groups was lower,than that of the control group(P＞0.05).The body weight of male mice in the acidified water group was higher,while that of other groups was lower,than that of control group,but there was no statistical difference between the groups(P＞0.05).The body weights of male and female mice in the solid water group were lower than those in the control group(P＜0.05).The food and water intake of the female animals in the alkaline water group and the water intake of female animals in the solid water group were lower than those of the other groups.OTU clustering analysis showed that the data volume of the sequencing was reasonable,and the fecal flora species of NIH mice were divided into five phyla,among which Bacteroides and Firmicutes were dominant.Unclassified Pseudopurpuromonas,Lactobacillus and Alistipes were the main genera.There were differences in fecal flora abundance and diversity among the mice given the five drinking water types.α analysis showed that the acidified water group had the highest flora abundance and diversity,while the solid water group had the lowest flora diversity.β analysis showed that the fecal flora composition in the solid water group was the closest to that of the control group,followed by the alkalized water group,acidified water group and weakly acidic water group.Conclusions Through an exploration of the effects of consuming different forms of water,this study revealed that solid water consumption had the greatest effects on body weight,feed intake,water consumption,and fecal flora of mice.The abundance and diversity of fecal flora in mice were affected by different pH values of drinking water,especially acidified water.

This review clarifies that laboratory animal welfare and ethics in life science research should be human-centered,positive and responsible through the understanding of the connotation of laboratory animal welfare.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Laboratory animals are not only a national strategic resource but also an important support for development of science and technology. The Committee of Identification and Evaluation for Laboratory Animal Resources, organized by Chinese Association for Laboratory Animal Sciences and established in May 2019, is currently the only specialized academic agency dedicated to the identification and evaluation of laboratory animal resources in China. This paper first discusses the significance of identifying and evaluating laboratory animal resources, summarizes three new approaches to developing these resources, including the domestication and standardization of laboratory animals (economic, ornamental, agricultural, and wild animals, etc.), the acquisition of new strains (species) through natural mutation and induced mutation, and the creation of new laboratory animal resources through gene editing technology. It then introduces the workflow for resource identification and evaluation, including preliminary review (format review), written review (expert review), joint review or on-site inspection, final review (voting and public announcement)，and the issuance of certificates. The required materials to be submitted include application, summary report, research or identification reports, appendices and other necessary documents. The paper further discusses related requirements for resource identification and evaluation, including population, genetic classification, biological characteristics, genetic stability, and application value. Finally, the current status of newly identified laboratory animal strains (species) and issues in current work practices are analyzed, as well as solutions to these issues. This paper aims to provide a valuable reference for further research in this field.

Objective To study the impact of a Western diet-type feed on biological indicators and histopathology in APOE-/-mice.Methods Forty-eight female and 48 male APOE--mice,and 48 female and 48 male C57BL/6J mice were divided into eight breeding groups:APOE-/-breeding feed group,APOE-/-Western dietary feed group,C57BL/6J breeding feed group,and C57BL/6J Western dietary feed group(24 male and 24 female mice per group).Mice were fed the respective diets from 3 weeks until the end of the experiment at 20 weeks.After the experiment,serum was collected for measurement of biochemical indicators.Aortas were removed for oil red O staining and gross examination and the aorta root was paraffin sectioned and stained with hematoxylin and eosin.Results A Western diet did not significantly increase body weight in APOE-/-mice,but did significantly improve the blood lipid index and total cholesterol,low-density lipoprotein,and high-density lipoprotein levels,and promoted the formation of atherosclerotic plaques.Male mice were suitable for modeling gross aortic plaques while female mice were suitable for modeling aortic arch root plaques.Conclusions A Western diet can promote atherosclerosis in APOE-/-mice,increase the aortic plaque area ratio,shorten modeling time,and improve modeling uniformity.

To investigate the effects of Pithecellobium clypearia extract on the tissue structure,in-flammatory lesions as well as microbial diversity in the intestinal of yellow-feathered broilers.2401-day-old yellow-feathered broilers were randomly divided into four groups(groups A,B,C and D),groups A,B and C were supplemented with Pithecellobium clypearia extract in basal diets with concentrations of 0.5,1.0 and 2.0 g/kg,respectively.Group D served as the control group without adding Pithecellobium clypearia extract in diets,and the full trial period lasted for 70 d.Duodenum and jejunum samples were collected on the 20th,40th and 70th days of the test,the vil-lous/crypt ratio of duodenum and jejunum were calculated,and the mRNA expression level of in-flammatory cytokine as well as related pathways were detected in each group,respectively.In addition,the contents of cecum were collected at 70 th day of the experiment and the microbial di-versity in cecum were also analysed by 16S rDNA sequencing.The results showed that adding 0.5 and 1.0 g/kg of Pithecellobium clypearia extract in the diet could significantly increase the veloci-ty height/crypt depth ratio of duodenum and jejunum(P＜0.05)compared to control group,as well as the mRNA expression level of tight junction protein(CLDN1 and CLDN5)in jejunum,which further improved the structure of mucous of intestinal.Pithecellobium clypearia extract could significantly(P＜0.05)decrease the mRNA expression level of inflammatory cytokine inclu-ding IL-1β,IL-8 and TNF-α,as well as the related pathway genes such as TLR4,MyD88 and NF-κB in jejunum,thus reduced the inflammatory lesions in intestinal.Pithecellobium clypearia ex-tract also could significantly increase the abundance of beneficial microbial such as Parabacteroide and Prevotellaceae,while significantly decrease the abundance of pathogenic microbial such as Proteobacteria in cecum(P＜0.05)and improve the microbial diversity in intestinal.In summary,Pithecellobium clypearia extract could improve the structure of intestinal tissue and the gut barri-er function,as well as the microbial diversity in cecum,and also decrease the inflammatory lesions in jejunum,which is helpful to the intestinal health for yellow-feathered broilers.The present study provides scientific basis for the development of Pithecellobium clypearia as a safe feed additive in the future.

Objective: To understand associated factors of myopia among middle school students in Zhengzhou and to explore the correlation between myopia with overweight and obesity, to provide a scientific basis for myopia prevention. Methods: A total of 3 297 middle school students from 8 middle schools in Erqi District, Zhongmu County and Xingyang County of Zhengzhou City were selected by a cluster random sampling method to participate in vision testing and questionnaire survey. Chi square test, and Logistic regression analysis were used. Results: Overall prevalence of myopia of middle school students was 80.5%, overweight 14.7%, obesity 10.1% in Zhengzhou. The prevalence of myopia differed significantly by schooling stage, parental myopia status and sex ( χ 2= 18.34, 23.55, 8.98, 26.53, 27.46, 47.25, P <0.05). Significant differences in myopia detection rate by after school homework duration were observed in boys and the entire population( χ 2=12.40, 15.25, P <0.01), and significant differences in myopia detection rate by body mass index (BMI) were only observed in boys ( χ 2=6.32, P <0.05). The distribution of myopia severity was statistically significant by sex among junior school students, and by BMI categories among high school students ( χ 2=22.71, 20.37, P <0.01). Multivariate binary Logistic regression analysis showed that the risk for myopia among school students who were overweight and obese was 1.81 times higher than that of students who were not overweight and obese( P <0.01). Conclusion Overweight and obesity might increase the risk of myopia among middle school students, targeted measures should be taken to maintain the healthy weight of middle school students and reduce the risk of myopia.

Objective:To study the short-term clinical outcomes of different courses of antenatal corticosteroids (ACS) for preterm twins.Methods:From January 2017 to December 2021, preterm twins with gestational age (GA) 24-34 weeks admitted to the neonatal ward of our hospital and received ACS were retrospectively studied. The infants were assigned into single-course group, partial-course group and multiple-course group according to ACS courses. The short-term clinical outcomes were compared among the groups. SPSS software version 25.0 was used for statistical analysis.Results:A total of 286 infants were enrolled in this study, including 128 in single-course group, 89 in partial-course group and 69 in multiple-course group. Compared with single-course group, the risks of neonatal respiratory distress syndrome (RDS) in both partial-course group ( OR=2.332, 95% CI 1.028-5.293, P=0.043) and multiple-course group ( OR=3.872, 95% CI 1.104-13.584, P=0.034) were higher. The birth length in multiple-course group ( β=-0.016, 95% CI -0.029 - -0.002, P=0.024) was lower than single-course group. Conclusions:The risks of neonatal RDS in preterm twins are higher in partial-course and multiple-course of ACS. A full course of ACS should be used to prevent neonatal RDS until further evidence of effectiveness is available.