Objective To establish a rapid and accurate droplet digital PCR(ddPCR)detection method for detecting Staphylococcus aureus(SA)in laboratory animals and the environment.Methods Using the heat-stable nuclease gene(nuc)of SA as the target gene,a pair of specific primers and probes are designed within its conserved region.Optimize the reaction conditions,test the dynamic range,and evaluate the specificity and stability of the method.Using the same template,test reactions were performed with both ddPCR and real-time quantitative PCR(qPCR)method to assess the interchangeability between the two approaches.Finally,the method is applied to the detection of various clinical samples.Results The kinetic range of the established SA ddPCR method is 100～15 000 copies/μL,with a detection limit of 2.5 copies and a quantification limit of 10 copies;The specificity of this method was tested,and only SA showed positive droplets,while no positive droplets were found for other pathogens;After measuring three parallel samples,the standard deviation and relative standard deviation were calculated.It was found that within the dynamic detection interval of ddPCR,as the target copy number gradually decreased,the relative standard deviation showed an upward trend,but remained below 25％.This result indicates that the detection method has good stability.Conclusions The established ddPCR method for detecting SA has the advantages of high sensitivity,strong specificity,good stability,and good reproducibility.This method can be applied for the detection of SA in laboratory animals.

Objective To investigate the differences in personality traits between the patients with anx-ious depression(AND)and non-anxious depression(NAD)in order to provide the possible basis for early find of the patients with AND.Methods A total of 572 adult patients with depression visiting in the psychiatric outpatient department of the First Affiliated Hospital of Chongqing Medical University from January 2022 to December 2022 were selected to conduct the questionnaire survey.General demographic questionnaire,Self-rating Depression Scale(SDS),Generalized Anxiety Disorder Scale(GAD-7)and Minnesota Multiphasic Per-sonality Inventory(MMPI)were collected and analyzed.The patients with GAD-7 total score ≥5 points served as the AND group(n=499)and those with GAD total score＜5 points served as the NAD group(n=73).The correlation between the general demographic questionnaire,SDS and GAD-7 with MMPI was ana-lyzed.Results There were statistically significant differences in the place of residence,number of children in a family,education years,MMPI total score and high score proportions of psychopathy,athopia,hysteria,depres-sion,hypochondriasis,paranoea,schizophrenia,social introversion and hypomania dimensions between the two groups(P＜0.05).The SDS and GAD-7 scores in the AND group were higher than those in the NAD group(P＜0.05).The MMPI total score,athopia,hysteria,depression,hypochondriasis,paranoea,schizophrenia,so-cial introversion and hypomania were positively correlated with SDS and GAD-7(P＜0.05).Conclusion The patients with depression accompanied by anxiety symptom could be early identified by the MMPI testing results.

Objective We aimed to investigate the effects of different non-surgical embryo transfer devices,number of transferred embryos,embryo stage,and embryos obtained from different mouse strains on the efficiency of non-surgical embryo transfer in mice,and to compare the efficiencies of surgical and non-surgical embryo transfer,in order to establish a stable non-surgical embryo transfer technology system.Methods Mouse embryo transfer was carried out using non-surgical method.Results The pregnancy rates using two different non-surgical transfer devices were(75.00±0.00)％and(66.67±14.43)％,and the birth rates were(46.11±6.31)％and(18.89±0.96)％,respectively.Transfer of 10,15,and 20 embryos resulted in pregnancy rates of(66.67±11.55)％,(80.00±0.00)％,and(66.67±23.09)％,and birth rates of(29.33±4.16)％,(38.67±4.81)％,and(17.00±3.46)％,respectively.When blastocysts and morulae were transferred non-surgically,the resulting pregnancy rates were(80.00±0.00)％and(46.67±11.55)％and the birth rates were(38.67±4.81)％and(10.22±2.77)％,respectively.Four strains(C57BL/6J,ICR,genetically modified mice A,genetically modified mice B)were used as donors for non-surgical embryo transfer,with resulting pregnancy rates of(66.67±11.55)％,(80.00±0.00)％,(73.33±11.55)％,and(80.00±0.00)％,and birthrates of(26.67±2.67)％,(38.67±4.81)％,(32.00±3.53)％,and(29.34±2.31)％,respectively.Fifteen pseudo-pregnant mice were transplanted surgically and 15 were transplanted non-surgically,with pregnancy rates of(80.00±0.00)％and(86.67±11.55)％,and birth rates of(38.67±4.81)％and(36.00±5.82)％,respectively.Conclusions Transfer device A resulted in a higher birth rate in this study.The embryo transfer efficiency was higher when 15 embryos were transferred into unilateral uterine horns of pseudo-pregnant 2.5-day recipients.Blastocyst-stage embryo transfer was more efficient than morula-stage transfer.There was no significant difference in efficiency between surgical and non-surgical embryo transfer procedures.

As an important and fundamental resource of scientific research,laboratory animals have become essential tools for the continuous advancements in life sciences,medical research,drug development,and other fields.With the development of related laws and regulations,the welfare of laboratory animals is increasingly valued by the general public and international research communities alike.To ensure the welfare of laboratory animals,the ethical review and conduct of laboratory animal practitioners should be standardized,incorporating and adapting advanced international practices with those in China.This article primarily outlines the process for reviewing and approving animal use protocols,along with the standards for evaluation,with the aim of providing a reference for researchers writing animal use protocols and for International Animal Care and Use Committee members conducting ethical reviews of laboratory animal welfare.

Radiation-induced heart disease(RIHD)is a severe complication in patients with thoracic cancer undergoing radiotherapy,with important impacts on long-term survival among cancer survivors.There is an urgent need to investigate the pathogenesis of RIHD and to develop effective therapeutic agents,and the establishment of high-quality RIHD animal models is pivotal to addressing these issues.This review summarizes the critical factors to consider in establishing RIHD animal models,including species selection,radiation type,dosage,fractionation,and target fields,and modeling timeline,along with the evaluation method and success criteria.We also consider the potential pathogenic mechanisms underlying RIHD,including DNA damage,oxidative stress,inflammatory responses,mitochondrial dysfunction,renin-angiotensin-aldosterone system activation,and myocardial fibrosis,as well as their interrelationships.These insights provide a comprehensive reference framework for constructing RIHD animal models and advancing mechanistic investigations into this condition.

Objective To establish a rapid and accurate droplet digital PCR(ddPCR)detection method for detecting Staphylococcus aureus(SA)in laboratory animals and the environment.Methods Using the heat-stable nuclease gene(nuc)of SA as the target gene,a pair of specific primers and probes are designed within its conserved region.Optimize the reaction conditions,test the dynamic range,and evaluate the specificity and stability of the method.Using the same template,test reactions were performed with both ddPCR and real-time quantitative PCR(qPCR)method to assess the interchangeability between the two approaches.Finally,the method is applied to the detection of various clinical samples.Results The kinetic range of the established SA ddPCR method is 100～15 000 copies/μL,with a detection limit of 2.5 copies and a quantification limit of 10 copies;The specificity of this method was tested,and only SA showed positive droplets,while no positive droplets were found for other pathogens;After measuring three parallel samples,the standard deviation and relative standard deviation were calculated.It was found that within the dynamic detection interval of ddPCR,as the target copy number gradually decreased,the relative standard deviation showed an upward trend,but remained below 25％.This result indicates that the detection method has good stability.Conclusions The established ddPCR method for detecting SA has the advantages of high sensitivity,strong specificity,good stability,and good reproducibility.This method can be applied for the detection of SA in laboratory animals.

Objective We aimed to investigate the effects of different non-surgical embryo transfer devices,number of transferred embryos,embryo stage,and embryos obtained from different mouse strains on the efficiency of non-surgical embryo transfer in mice,and to compare the efficiencies of surgical and non-surgical embryo transfer,in order to establish a stable non-surgical embryo transfer technology system.Methods Mouse embryo transfer was carried out using non-surgical method.Results The pregnancy rates using two different non-surgical transfer devices were(75.00±0.00)％and(66.67±14.43)％,and the birth rates were(46.11±6.31)％and(18.89±0.96)％,respectively.Transfer of 10,15,and 20 embryos resulted in pregnancy rates of(66.67±11.55)％,(80.00±0.00)％,and(66.67±23.09)％,and birth rates of(29.33±4.16)％,(38.67±4.81)％,and(17.00±3.46)％,respectively.When blastocysts and morulae were transferred non-surgically,the resulting pregnancy rates were(80.00±0.00)％and(46.67±11.55)％and the birth rates were(38.67±4.81)％and(10.22±2.77)％,respectively.Four strains(C57BL/6J,ICR,genetically modified mice A,genetically modified mice B)were used as donors for non-surgical embryo transfer,with resulting pregnancy rates of(66.67±11.55)％,(80.00±0.00)％,(73.33±11.55)％,and(80.00±0.00)％,and birthrates of(26.67±2.67)％,(38.67±4.81)％,(32.00±3.53)％,and(29.34±2.31)％,respectively.Fifteen pseudo-pregnant mice were transplanted surgically and 15 were transplanted non-surgically,with pregnancy rates of(80.00±0.00)％and(86.67±11.55)％,and birth rates of(38.67±4.81)％and(36.00±5.82)％,respectively.Conclusions Transfer device A resulted in a higher birth rate in this study.The embryo transfer efficiency was higher when 15 embryos were transferred into unilateral uterine horns of pseudo-pregnant 2.5-day recipients.Blastocyst-stage embryo transfer was more efficient than morula-stage transfer.There was no significant difference in efficiency between surgical and non-surgical embryo transfer procedures.

As an important and fundamental resource of scientific research,laboratory animals have become essential tools for the continuous advancements in life sciences,medical research,drug development,and other fields.With the development of related laws and regulations,the welfare of laboratory animals is increasingly valued by the general public and international research communities alike.To ensure the welfare of laboratory animals,the ethical review and conduct of laboratory animal practitioners should be standardized,incorporating and adapting advanced international practices with those in China.This article primarily outlines the process for reviewing and approving animal use protocols,along with the standards for evaluation,with the aim of providing a reference for researchers writing animal use protocols and for International Animal Care and Use Committee members conducting ethical reviews of laboratory animal welfare.

Radiation-induced heart disease(RIHD)is a severe complication in patients with thoracic cancer undergoing radiotherapy,with important impacts on long-term survival among cancer survivors.There is an urgent need to investigate the pathogenesis of RIHD and to develop effective therapeutic agents,and the establishment of high-quality RIHD animal models is pivotal to addressing these issues.This review summarizes the critical factors to consider in establishing RIHD animal models,including species selection,radiation type,dosage,fractionation,and target fields,and modeling timeline,along with the evaluation method and success criteria.We also consider the potential pathogenic mechanisms underlying RIHD,including DNA damage,oxidative stress,inflammatory responses,mitochondrial dysfunction,renin-angiotensin-aldosterone system activation,and myocardial fibrosis,as well as their interrelationships.These insights provide a comprehensive reference framework for constructing RIHD animal models and advancing mechanistic investigations into this condition.

Objective To investigate the difference of depressive symptoms between adolescents and adults,and to provide possible basis for early detection of adolescent depression.Methods From July 2021 to June 2022,a total of 4 096 patients with"depression"in the psychiatric clinic of the First Affiliated Hospital of Chongqing Medical University were selected as the research objects.They were divided into the adolescent group(n=2 439)and adult group(n=1 657)according to their ages,and the results of self-rating depression scale(SDS)and symptom checklist 90(SCL-90)were collected and analyzed.Results There were significant differences in nationality,residence,native place,family history and degree of depression between the two groups(P<0.05).The adolescent group has more severe depressive symptoms,which were mainly manifes-ted in negative ideas,obsessive-compulsive symptoms,hostile and interpersonal relationship,and psychotic symptoms(P<0.05).The adult group showed more obvious in sleep(P<0.05).Conclusion Early inter-vention should be carried out for adolescents'depressive symptoms such as negative thoughts.