OBJECTIVE To observe the in vitro induced drug resistance mechanisms of polymyxin B-resistant Acin-etobacter baumannii and explore the in vitro antimicrobial activity of polymyxin B combined with melatonin.METHODS Totally 10 strains of polymyxin B-sensitive A.baumannii were clinically isolated from the Affiliated Li Huili Hospital of Ningbo university between Jan.2021 to Dec.2021 and were induced to the polymyxin B-resistant strains by means of in vitro induction method.The drug resistance mechanisms of the polymyxin B-resistant A.baumannii strains were explored by polymerase chain reaction(PCR)combined with sequencing analysis.The minimum inhibitory concentrations(MICs)of the single and joint use of polymyxin B and melatonin were detected by using broth microdilution checkerboard.The antibacterial effect of polymyxin combined with melatonin was e-valuated by calculating fractional inhibitory concentration index(FICI).The strains that showed the remarkable synergistic effect for the antimicrobial activity were chosen to determine the time-kill curves.RESULTS Among the polymyxin B-induced drug-resistant A.baumannii strains,there were gene mutations at various loci of polymyxin resistance genes pmrB,lpxA and lpxD.The MIC of polymyxin B against A.baumannii strains declined after the combined use of polymyxin B and melatonin.The combined use of the two drugs that showed synergistic effect for antimicrobial activity accounted for 80.00％(8/10),the additive effect 20.00％(2/10).The time-kill curve showed that the combined use of polymyxin B and melatonin showed remarkable antibacterial effect at the 24th hour.CONCLUSIONS The drug resistance gene mutations that are mediated by chromosomes are the major drug resist-ance mechanisms of the A.baumannii strains to polymyxin B.The combined use of polymyxin B and melatonin may reverse the drug resistance of the A.baumannii to polymyxin B.

Objective:To observe the efficacy and safety of polatuzumab vedotin(pola)combined with chemotherapy in the treatment of relapsed and refractory diffuse large B-cell lymphoma(R/R DLBCL).Methods:A total of 23 patients with R/R DLBCL treated at the First Affiliated Hospital of Zhejiang University and its Liangzhu Branch from April 2023 to March 2024 were retrospectively collected.All patients were treated with pola combined with chemotherapy regimens such as BR,R-GDP,R-CHOP,or other regimens.Results:All 23 patients were evaluable for efficacy,with 10 achieving complete response(CR),7 partial response(PR),3 stable disease(SD),and 3 progressive disease(PD).The most common adverse events included myelosuppression,fever,and pulmonary infection.No severe adverse events resulted in drug withdrawal.Conclusion:Pola combined with chemotherapy demonstrates promising efficacy and a favorable safety profile in the treatment of R/R DLBCL.

Sepsis is a life-threatening organ dysfunction disease caused by a dysregulated host response to infection.It has com-plex pathophysiological changes,and in severe cases,it can rap-idly develop into septic shock and multiple organ dysfunction or multiple organ failure.At present,the pathological mechanism of sepsis and its induced organ dysfunction is complex and the in-fluencing factors are numerous.So far,there is still a lack of specific and effective treatment strategies.RNA modify-N6-methyladenosine(m6 A)is one of the most common post-tran-scriptional modifications on eukaryotic RNAs.It is involved in the regulation of the occurrence and development of a variety of inflammatory diseases,including sepsis,and even multiple organ dysfunction induced by sepsis by affecting the metabolism of RNAs.It includes cardiac dysfunction,acute lung injury(ALI)and acute kidney injury(AKI).Therefore,this article will dis-cuss the effect of m6A modification on the function of immune cells,and its important role in sepsis and its induced multiple or-gan dysfunction diseases by regulating inflammatory signals,py-roptosis,mitochondrial damage and ferroptosis.This will provide new therapeutic targets and strategies for the clinical prevention and treatment of sepsis and its induced multiple organ dysfunc-tion diseases.

In the field of substance detection,ion dissociation techniques have become crucial for enhancing qualitative accuracy.By applying external energy to induce dissociation of ions in the substance being analyzed,the internal structural information can be obtained,thereby improving qualitative capabilities.Current research on ion dissociation techniques primarily focuses on tandem mass spectrometry,which typically requires a vacuum environment.However,research on ambient ion dissociation techniques is less developed,with some progress made in the field of tandem ion mobility spectrometry.Recently,the development of field-induced dissociation(FID)in this area has enabled ambient dissociation of various explosive and volatile alcohol ions.Nevertheless,the limitation imposed by the maximum breakdown field of air restricts the energy of the electric field,making it challenging to dissociate ions with high energy requirements,such as those of drugs.To address this issue,in this work,an ambient heat-induced dissociation(HID)technique based on high temperatures was proposed,in which an ambient ion heat-induced dissociation unit was developed and integrated into a home-made ion trap mass spectrometer.Experiments were conducted on four representative drug samples,e.g.methamphetamine,heroin,cocaine,and ketamine.The parent ions mass spectra,low vacuum collision-induced dissociation(CID)mass spectra and ambient HID mass spectra for each sample were obtained.By analyzing and comparing the fragmentation products from ambient and low vacuum dissociation,the feasibility of the ambient HID technique was verified.This technique provided a method for ion dissociation in single mass analyzers without tandem mass spectrometry capability and offered a new research direction for the future development of tandem ion mobility spectrometry.

Objective To compare the application effects of plankton multiplex polymerase chain reac-tion-capillary electrophoresis(PCR-CE),SYBR Green Ⅰ real-time quantitative PCR(qPCR)and microwave digestion-vacuum filtration-automated scanning electron microscopy(MD-VF-Auto SEM)in the diagnosis of drowning.Methods Lung,liver and kidney tissues from 212 drowned corpses and 30 non-drowned corpses were examined respectively by the three drowning-related plankton testing methods,and the detection rates of plankton in each tissue by three methods were compared.Results In drowned corpses,the total detection rates of PCR-CE,qPCR,and MD-VF-Auto SEM were 93.9%,96.2%,and 95.3%,respectively,with no statistically significant difference(P>0.05).The detection rate of lung tissue by MD-VF-Auto SEM(100%)was higher than those of PCR-CE and qPCR(P<0.05),and there was no significant difference in the detection rates of the three methods in liver or kidney tissues(P>0.05).In non-drowning corpses,a small number of diatoms(less than 10 cells/10 g)were detected by MD-VF-Auto SEM method,only in liver and kidney tissues,while the other two methods yielded negative results for all tissues.Conclusion All three methods have good efficacy in the examination of drowned corpses.The MD-VF-Auto SEM method directly observes diatom morpho-logical characteristics through scanning electron microscopy,and the qualitative and quantitative analy-ses are intuitive and accurate.It has great advantages in the examination of difficult degradation samples.The PCR-CE method and qPCR method have a low sample demand(0.5 g),are easy to operate and have short detection time(4-7 h).They are easy to be applied in the grassroots depart-ments and are suitable for the rapid determination of drowned corpses in routin cases.The combina-tion of the two DNA methods with the MD-VF-Auto SEM method can increase the detection rate of plankton,ensuring the reliability of examination results.This combined use is of significant importance in the application of drowning diagnosis.

Objective To explore the influencing factors of immune-associated thyroid dysfunction caused by sintilimab treatment in solid tumors and construct a prediction model.Methods Medical records of patients diagnosed with solid tumors and treated with sintilimab at Peking University People's Hospital(Xizhimen Campus,Tongzhou Campus,Shijiazhuang Campus)from January 2023 to September 2024 were collected to explore the influencing factors that caused immune-related thyroid dysfunction using univariate and multifactorial binary logistic regression analyses and to establish a prediction model.The predictive effect of the model was assessed using the receiver operating characteristic(ROC)curve.Results A total of 120 patients were included,and 33 presented with immune-related thyroid dysfunction.Multifactorial logistic regression analysis revealed that thyroid-stimulating hormone(TSH)[OR=2.470,95%CI=(1.279,4.771)]and treatment cycles[OR=1.298,95%CI=(1.117,1.509)]were independent risk factors for the occurrence of immune-associated thyroid dysfunction,and the difference was statistically significant(P＜0.05).The area under the ROC curve was(0.897±0.043)[95%CI=(0.813,0.981)],the Yoden index was 0.703,and the model prediction accuracy was 86.5%.Conclusion The risk of immune-related thyroid dysfunction caused by sintilimab is high,and TSH and treatment cycle are the influencing factors,and the constructed model has certain predictive value and is of reference significance.

Objective To investigate the mechanisms by which paeoniflorin improves tissue and cell damage caused by diabetic retinopathy(DR)through the hypoxia-induced factor-1α(HIF-1α)pathway.Methods Thirty rats were ran-domly divided into a control group(10 normal rats),a DR group(10 diabetic model rats)and a paeoniflorin group(10 dia-betic model rats given 80 mg·kg-1 paeoniflorin by gavage).Rat retinal microvascular endothelial cells(rRMECs)were di-vided into a control group(cultured with 5 mmol·L-1 glucose),a high glucose group(cultured with 30 mmol·L-1 glu-cose)and a paeoniflorin group(cultured with 30 mmol·L-1 glucose and 20 mol·L-1 paeoniflorin).The three groups of cells were all cultured for 24 h.Fasting blood glucose was measured by a glucose meter.Hematoxylin and eosin(HE)stai-ning was used to detect the retinal histopathological structure.The levels of HIF-1α and vascular endothelial growth factor(VEGF)proteins and mRNAs in retinal tissues and rRMECs were detected by Western blotting and real time quantitative polymerase chain reaction(RT-qPCR).The proliferative ability of rRMECs was detected by the EdU kit.The serum levels of total cholesterol(TC),triglyceride(TG),low density cholesterol(LDL-C),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in retinal tissues and rRMECs were detected by kits.The activity and invasive ability of rRMECs were measured by CCK-8 and Transwell assay,respectively.The levels of HIF-1α and VEGF proteins in rRMECs were detected by immunofluorescence staining.Results Compared with those in the DR group,the fasting blood glucose,TC,TG and LDL-C levels in the paeoniflorin group were significantly decreased(all P＜0.05).The retinal tissue was loose with an un-clear boundary in the DR group,compared with that in the control group.The retinal tissue in the paeoniflorin group was less loose with a clearer boundary than that in the DR group.The levels of HIF-1α and VEGF proteins and mRNAs,TNF-αand IL-6 in retinal tissues of the DR group were significantly higher than those of the control group(all P＜0.05).The lev-els of HIF-1α and VEGF proteins and mRNAs,TNF-α and IL-6 in retinal tissues of the paeoniflorin group were significantly lower than those in the DR group(all P＜0.05).The activity,proliferation and invasive abilities of rRMECs in the high glu-cose group were higher than those in the control group(all P＜0.05).Compared with those in the high glucose group,rRMECs in the paeoniflorin group showed decreased cell activity,proliferation and invasive abilities(all P＜0.05).The lev-els of HIF-1α and VEGF proteins and mRNAs,TNF-α and IL-6 in the rRMECs of the high glucose group were higher than those of the control group(all P＜0.05).The levels of HIF-1α and VEGF proteins and mRNAs,TNF-α and IL-6 in the rRMECs of the paeoniflorin group were lower than those of the high glucose group(all P＜0.05).Conclusion Paeoni-florin can down-regulate the HIF-1α/VEGF pathway to improve the inflammatory injury of the retinal tissue and inhibit rRMEC activity,proliferation and invasive abilities in DR rats,thereby preventing angiogenesis and reducing the incidence of DR.

Objective To investigate the mechanisms by which paeoniflorin improves tissue and cell damage caused by diabetic retinopathy(DR)through the hypoxia-induced factor-1α(HIF-1α)pathway.Methods Thirty rats were ran-domly divided into a control group(10 normal rats),a DR group(10 diabetic model rats)and a paeoniflorin group(10 dia-betic model rats given 80 mg·kg-1 paeoniflorin by gavage).Rat retinal microvascular endothelial cells(rRMECs)were di-vided into a control group(cultured with 5 mmol·L-1 glucose),a high glucose group(cultured with 30 mmol·L-1 glu-cose)and a paeoniflorin group(cultured with 30 mmol·L-1 glucose and 20 mol·L-1 paeoniflorin).The three groups of cells were all cultured for 24 h.Fasting blood glucose was measured by a glucose meter.Hematoxylin and eosin(HE)stai-ning was used to detect the retinal histopathological structure.The levels of HIF-1α and vascular endothelial growth factor(VEGF)proteins and mRNAs in retinal tissues and rRMECs were detected by Western blotting and real time quantitative polymerase chain reaction(RT-qPCR).The proliferative ability of rRMECs was detected by the EdU kit.The serum levels of total cholesterol(TC),triglyceride(TG),low density cholesterol(LDL-C),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in retinal tissues and rRMECs were detected by kits.The activity and invasive ability of rRMECs were measured by CCK-8 and Transwell assay,respectively.The levels of HIF-1α and VEGF proteins in rRMECs were detected by immunofluorescence staining.Results Compared with those in the DR group,the fasting blood glucose,TC,TG and LDL-C levels in the paeoniflorin group were significantly decreased(all P＜0.05).The retinal tissue was loose with an un-clear boundary in the DR group,compared with that in the control group.The retinal tissue in the paeoniflorin group was less loose with a clearer boundary than that in the DR group.The levels of HIF-1α and VEGF proteins and mRNAs,TNF-αand IL-6 in retinal tissues of the DR group were significantly higher than those of the control group(all P＜0.05).The lev-els of HIF-1α and VEGF proteins and mRNAs,TNF-α and IL-6 in retinal tissues of the paeoniflorin group were significantly lower than those in the DR group(all P＜0.05).The activity,proliferation and invasive abilities of rRMECs in the high glu-cose group were higher than those in the control group(all P＜0.05).Compared with those in the high glucose group,rRMECs in the paeoniflorin group showed decreased cell activity,proliferation and invasive abilities(all P＜0.05).The lev-els of HIF-1α and VEGF proteins and mRNAs,TNF-α and IL-6 in the rRMECs of the high glucose group were higher than those of the control group(all P＜0.05).The levels of HIF-1α and VEGF proteins and mRNAs,TNF-α and IL-6 in the rRMECs of the paeoniflorin group were lower than those of the high glucose group(all P＜0.05).Conclusion Paeoni-florin can down-regulate the HIF-1α/VEGF pathway to improve the inflammatory injury of the retinal tissue and inhibit rRMEC activity,proliferation and invasive abilities in DR rats,thereby preventing angiogenesis and reducing the incidence of DR.

Objective:The genotoxicity risk of graphene artificial nerve sheath conduit was systematically evaluated to provide scientific evidence for their clinical safety and to establish methodological references for the genotoxicity assessment of nanomaterial medical devices.Methods:The potential effects of graphene artificial nerve sheath conduit on genetic and chromosomal endpoints were analyzed by integrating bacterial reverse mutation assays,in vitro chromosome aberration assays,mouse lymphoma cell TK gene mutation tests,and mammalian erythrocyte Pig-a gene mutation assays.Results:In the bacterial reverse mutation assay,all plates showed good background growth.There was no significant difference in the average number of revertant colonies between the test group and the negative control group,with a ratio around 1.0.In the in vitro chromosome aberration assay,the chromosomal aberration rate in the test group was less than 5％,showing no significant increase compared to the negative control group.In the mouse lymphoma cell TK gene mutation assay,the mutation frequency in the test group was less than twice that of the negative control group,with no significant difference.In the mammalian erythrocyte Pig-a gene mutation assay,the mutation frequencies of erythrocytes and reticulocytes in the test group were both less than 3× 10-6,showing no significant difference compared to the negative control group.Conclusions:Graphene artificial nerve sheath conduit exhibited no detectable genotoxicity under the tested conditions,the research results can provide reference and guidance for the genotoxicity evaluation of nanomaterial medical devices.

The success of"New Medical Sciences"in higher education requires effective tools in evalua-ting students'performance in courses.Previously,we reported a teamwork(T),critique(C)and ap-preciation(A)(TCA)ideological and political model,a teaching model widely applied in Basic Medical courses.TCA is an abbreviation derived from Tricarboxylic Acid Cycle in Biochemistry as an analogy for nurturing the abilities of thinking and teamwork(T),critique(C)and appreciation(A),which hope-fully could provide students with moral norms for cognition,science and life.This paper further explores the tools to assess the educational outcomes of the TCA model,by which teachers can collect feedback and reflect on teaching quality and effectiveness.Addressing the challenges of individual differences in large classes,fragmented learning feedback,and the difficulty of measuring meta-cognition in educational evaluation,this study employs strategies of value-added assessment,matrix assessment and norm-transfer-able assessment to evaluate the TCA abilities from the aspects of thinking quality,thinking creativity,co-operation ability,iterative thinking,dialectical thinking and job responsibility.By modifying/using 18 e-valuation tools in Education and Psychology,we have established a rubric system composed of 30 primary indicators(with 11 newly designed,10 partly modified and 9 directly adopted),along with 49 secondary indicators and 98 tertiary indicators to enhance the feasibility of the evaluation process.This rubric sys-tem was applied to Biochemistry teaching among the five-year-program undergraduates at Air Force Medi-cal University.Specifically,thinking and teamwork are evaluated by creative works from"the magic bio-chemical-circle",while critiques are assessed in large classes under the guidance of basic and clinical teachers,coupled with appreciation measured by job responsibility in a task-driven virtual reality(VR)project.The results indicate that Biochemistry teaching not only accumulates knowledge in students,but also achieves the goals in nurturing values and cognition.The inclusion of creative performance evalua-tion,cooperative learning and clinical case studies,can enhance students'interpersonal skills,coopera-tion,quality of thinking,creative thinking,iterative thinking and dialectical thinking to varying degrees.TCA-based Biochemistry teaching has a long-lasting impact on character education,and is capable of in-ducing positive long-term changes in students'cognition and lifestyle.Taken together,with the help of this rubric system,teachers can promptly acknowledge the effectiveness of their teaching,thereby facilita-ting their teaching strategies.