The xylitol dehydrogenase(XDH)is a crucial enzyme involved in the xylose utilization in pentose-catabolizing yeasts and fungi.In addition to producing xylulose,XDH can also be employed to develop a biosensor for monitoring xylitol concentration.In this study,the gene encoding the thermophilic fungus Talaromyces emersonii XDH(TeXDH)was heterologously expressed in Escherichia coli BL21(DE3)at 16 ℃ in the soluble form.Recombinant TeXDH with high purity was purified by using a Ni-NTA affinity column.Size-exclusion chromatography and SDS-PAGE analysis demonstrated that the puri-fied recombinant TeXDH exists as a native trimer with a molecular mass of approximately 116 kD,and is composed of three identical subunits,each with a molecular weight of around 39 kD.The TeXDH strictly preferred NAD+as a coenzyme to NADP+.The optimal temperature and pH of the TeXDH were 40 ℃and 10.0,respectively.After EDTA treatment,the enzyme activity of TeXDH decreased to 43.26％of the initial enzyme activity,while the divalent metal ions Mg2+or Ca2+could recover the enzyme activity of TeXDH,reaching 103.32％and 110.69％of the initial enzyme activity,respectively,making them the optimal divalent metal ion cofactors for TeXDH enzyme.However,the divalent metal ions of Mn2+,Ni2+,Cu2+,Zn2+,Co2+,and Cd2+significantly inhibited the activity of TeXDH.ICP-MS and molecular doc-king studies revealed that 1 mol/L of TeXDH bound 2 mol/L Zn2+ions and 1 mol/L Mg2+ion.Further-more,TeXDH exhibited a high specificity for xylitol,laying the foundation for the development of future xylitol biosensors.

Objective:To understand the etiological surveillance and drug resistance characteristics of Legionella pneumophila (LP) from the aqueous environment of public places in Shanghai, from 2011 to 2020, and provide evidence for surveillance of the disease. Methods:Environmental water samples were systematically collected from public venues in urban and suburban districts of Shanghai for LP surveillance. All the identified LP isolates underwent a series of testings including serotyping, pulsed field gel electrophoresis (PFGE), sequence-based typing, and antimicrobial susceptibility testing. χ2 test or Cochran-Armitage trend tests were used for statistical analysis and for temporal resistance patterns. Results:Among 6 263 water samples, the LP-positive rate was 20.93% (1 311/6 263). The positivity rate decreased from 24.98% (287/1 149) in 2011-2012 to 20.02% (1 024/5 114) in 2013-2020 ( χ2=13.92, P<0.001), with the highest monthly positivity observed from June to August (23.79%, 745/3 132). A total of 1 365 LP strains were isolated, of which 912 were further characterized, including 10 serotypes, 149 PFGE patterns, and 33 sequence types (ST). The predominant serotype was Lp1 (86.84%, 792/912), and the dominant ST was ST752 (29.50%, 269/912). ST clustering revealed two major clonal groups CG1 and CG2, accounting for 91.12% (831/912) of the isolates. The 190 LPs involved in the drug sensitivity test showed three resistance profiles: azithromycin resistance (31.05%, 59/190), ciprofloxacin resistance (0.53%, 1/190) and azithromycin+ciprofloxacin resistance (0.53%, 1/190). Azithromycin-resistant strains were predominantly ST1 (64.41%, 38/59). The antimicrobial resistance rate showed a significant decline, from 48.65% (18/37) in 2011-2012 to 28.10% (43/153) in 2013-2020 ( χ2=9.38, P=0.002). Conclusions:Compared to from 2011 to 2012, both the positivity rate and antimicrobial resistance prevalence of LP in public aqueous environments of Shanghai exhibited an overall decline from 2013 to 2020. The predominant types of LP were serotype Lp1 and sequence type ST752, with notable high-level resistance to azithromycin. Measures as enhancing the enforcement of water safety regulations and prioritizing surveillance of azithromycin resistance in LP were recommended to mitigate public health risks.

Objective Exploring the components of complex scenarios of healthcare surges triggered by major epidemics to provide a theorical basis for building resilience in healthcare organizations.Methods A hybrid analysis method is used to summarize macro-meso-micro multi-level and multi-source heterogeneous information,extract the elements of complex scenarios of medical surge and evaluate the rationality.Fault Tree Analysis method is used to clarify the logical relationship between various scenario elements and construct scenario reasoning paths.Results 10 scenario states,11 disaster-bearing,24 emergency management and 23 scenario results are summarized and extracted to form the key elements of complex surge scenarios.Among them,M4 expansion and coordinated scheduling of key positions,B2 conventional drug inventory emergency/insufficient core treatment drugs,B emergency medical material transportation breakage,S3 disease symptom spectrum shift to severe disease,R13 prevention and control awareness laxity,and M5 media information dissemination management are the key driving factors that promote a major turning point in the scenario.The most positive scenario result is the orderly operation of the medical service system,and the most negative scenario result is the paralysis of the medical service system.Conclusion Medical institutions need to improve emergency plans based on the complex evolution scenarios of medical surges and agile governance capabilities targeting key turning points,focus on dynamically expanding and scheduling personnel in key positions,strengthen material rotation and reserve mechanisms,maintain smooth emergency logistics channels,and improve efficient management of media and public opinion,so as to comprehensively improve overall resilience.

This study examines the effects of zearalenone(ZEA)on the survival and function of lu-teinized granulosa cells,and studies the role of activating transcription factor 6(ATF6)in regula-ting apoptosis and functional abnormalities of luteinized granulosa cells induced by ZEA.An in vitro model of luteinized granulosa cells was utilized to examine the effects of ZEA treatment on apoptosis,hormone secretion,and the expression of relevant proteins.Furthermore,the expression of ATF6 was manipulated using siRNA to elucidate its regulatory function in the ZEA-induced damage of luteinized granulosa cells in mice.Our findings revealed that ZEA inhibited the activity of luteinized granulosa cells and reduced the secretion of estradiol(E2)and progesterone(P4)in a dose-dependent manner.The expression levels of p-IRE1,ATF6 and StAR in both low(20 pmol/L)and high(40 μmol/L)ZEA groups were significantly increased after 24 h(P＜0.05).GRP78 had no significant change at low concentration treatment(P＞0.05),but significantly increased at high concentration treatment(P＜0.05).Similarly,ATF4 and p-EIF2α had no significant change at low concentration treatment(P＞0.05),but significantly decreased at high concentration treat-ment(P＜0.05).HSD3B2 and CYP19A1 were significantly decreased in both low and high concentration treatments(P＜0.05).After 48 h of treatment,ATF6 and GRP78 were significantly increased in both low and high concentration treatments(P＜0.05).p-IRE1 was significantly de-creased at low concentration treatment(P＜0.05),but remained unchanged at high concentration treatment(P＞0.05).ATF4,p-EIF2α,HSD3B2 and CYP19A1 were significantly decreased in both low and high concentration treatments(P＜0.05).St AR was significantly increased in both low and high concentration treatments(P＜0.05).Interference with the expression of ATF6 could sig-nificantly reduce the apoptosis induced by low concentration group(P＜0.05),and enhanced the hormone secretion in both high and low concentration groups(P＜0.05).In conclusion,ZEA can cause damage to luteinized granulosa cells and activate ATF6 signaling pathway.Interference with ATF6 can alleviate apoptosis and hormone secretion disturbance induced by low concentration ZEA,but has limited effect on damage caused by high concentration ZEA.

This study examines the effects of zearalenone(ZEA)on the survival and function of lu-teinized granulosa cells,and studies the role of activating transcription factor 6(ATF6)in regula-ting apoptosis and functional abnormalities of luteinized granulosa cells induced by ZEA.An in vitro model of luteinized granulosa cells was utilized to examine the effects of ZEA treatment on apoptosis,hormone secretion,and the expression of relevant proteins.Furthermore,the expression of ATF6 was manipulated using siRNA to elucidate its regulatory function in the ZEA-induced damage of luteinized granulosa cells in mice.Our findings revealed that ZEA inhibited the activity of luteinized granulosa cells and reduced the secretion of estradiol(E2)and progesterone(P4)in a dose-dependent manner.The expression levels of p-IRE1,ATF6 and StAR in both low(20 pmol/L)and high(40 μmol/L)ZEA groups were significantly increased after 24 h(P＜0.05).GRP78 had no significant change at low concentration treatment(P＞0.05),but significantly increased at high concentration treatment(P＜0.05).Similarly,ATF4 and p-EIF2α had no significant change at low concentration treatment(P＞0.05),but significantly decreased at high concentration treat-ment(P＜0.05).HSD3B2 and CYP19A1 were significantly decreased in both low and high concentration treatments(P＜0.05).After 48 h of treatment,ATF6 and GRP78 were significantly increased in both low and high concentration treatments(P＜0.05).p-IRE1 was significantly de-creased at low concentration treatment(P＜0.05),but remained unchanged at high concentration treatment(P＞0.05).ATF4,p-EIF2α,HSD3B2 and CYP19A1 were significantly decreased in both low and high concentration treatments(P＜0.05).St AR was significantly increased in both low and high concentration treatments(P＜0.05).Interference with the expression of ATF6 could sig-nificantly reduce the apoptosis induced by low concentration group(P＜0.05),and enhanced the hormone secretion in both high and low concentration groups(P＜0.05).In conclusion,ZEA can cause damage to luteinized granulosa cells and activate ATF6 signaling pathway.Interference with ATF6 can alleviate apoptosis and hormone secretion disturbance induced by low concentration ZEA,but has limited effect on damage caused by high concentration ZEA.

Since the concept of artificial intelligence(AI)was proposed in 1956,medicine has been one of its core application fields.At present,AI technology has run through the whole diagnosis and treatment process,and has been extended to innovative scenarios such as drug research and development,surgical robots,and clinical trial optimization.Scenario application is the backbone of the technical system.Multimodal data fusion integrates heterogeneous data such as images,medical records,and genes,and federated learning realizes cross-institutional privacy protection and sharing.Deep learning achieved more than 90%sensitivity in imaging diagnosis for lung nodule detection,while generative AI accelerates drug molecule design.The core applications cover four major areas field:AI is more accurate than professional doctors in breast cancer and diabetic retinopathy screening;robotics shortens hospital stays and improves spinal screw placement accuracy;AI shortens the discovery cycle of drug targets;machine learning improves the efficiency of subject screening and enables real-time data monitoring.The application of AI in the medical field is first constrained by data quality and algorithm bias,and the"black box"characteristics of AI models and the ambiguity of responsibility attribution are the core obstacles to clinical implementation.This paper analyzes key technological breakthroughs and typical cases,discusses the application scenarios and challenges of AI in medicine,and aims to provide a reference for the future development of medical intelligence.

The xylitol dehydrogenase(XDH)is a crucial enzyme involved in the xylose utilization in pentose-catabolizing yeasts and fungi.In addition to producing xylulose,XDH can also be employed to develop a biosensor for monitoring xylitol concentration.In this study,the gene encoding the thermophilic fungus Talaromyces emersonii XDH(TeXDH)was heterologously expressed in Escherichia coli BL21(DE3)at 16 ℃ in the soluble form.Recombinant TeXDH with high purity was purified by using a Ni-NTA affinity column.Size-exclusion chromatography and SDS-PAGE analysis demonstrated that the puri-fied recombinant TeXDH exists as a native trimer with a molecular mass of approximately 116 kD,and is composed of three identical subunits,each with a molecular weight of around 39 kD.The TeXDH strictly preferred NAD+as a coenzyme to NADP+.The optimal temperature and pH of the TeXDH were 40 ℃and 10.0,respectively.After EDTA treatment,the enzyme activity of TeXDH decreased to 43.26％of the initial enzyme activity,while the divalent metal ions Mg2+or Ca2+could recover the enzyme activity of TeXDH,reaching 103.32％and 110.69％of the initial enzyme activity,respectively,making them the optimal divalent metal ion cofactors for TeXDH enzyme.However,the divalent metal ions of Mn2+,Ni2+,Cu2+,Zn2+,Co2+,and Cd2+significantly inhibited the activity of TeXDH.ICP-MS and molecular doc-king studies revealed that 1 mol/L of TeXDH bound 2 mol/L Zn2+ions and 1 mol/L Mg2+ion.Further-more,TeXDH exhibited a high specificity for xylitol,laying the foundation for the development of future xylitol biosensors.

Objective:To understand the etiological surveillance and drug resistance characteristics of Legionella pneumophila (LP) from the aqueous environment of public places in Shanghai, from 2011 to 2020, and provide evidence for surveillance of the disease. Methods:Environmental water samples were systematically collected from public venues in urban and suburban districts of Shanghai for LP surveillance. All the identified LP isolates underwent a series of testings including serotyping, pulsed field gel electrophoresis (PFGE), sequence-based typing, and antimicrobial susceptibility testing. χ2 test or Cochran-Armitage trend tests were used for statistical analysis and for temporal resistance patterns. Results:Among 6 263 water samples, the LP-positive rate was 20.93% (1 311/6 263). The positivity rate decreased from 24.98% (287/1 149) in 2011-2012 to 20.02% (1 024/5 114) in 2013-2020 ( χ2=13.92, P<0.001), with the highest monthly positivity observed from June to August (23.79%, 745/3 132). A total of 1 365 LP strains were isolated, of which 912 were further characterized, including 10 serotypes, 149 PFGE patterns, and 33 sequence types (ST). The predominant serotype was Lp1 (86.84%, 792/912), and the dominant ST was ST752 (29.50%, 269/912). ST clustering revealed two major clonal groups CG1 and CG2, accounting for 91.12% (831/912) of the isolates. The 190 LPs involved in the drug sensitivity test showed three resistance profiles: azithromycin resistance (31.05%, 59/190), ciprofloxacin resistance (0.53%, 1/190) and azithromycin+ciprofloxacin resistance (0.53%, 1/190). Azithromycin-resistant strains were predominantly ST1 (64.41%, 38/59). The antimicrobial resistance rate showed a significant decline, from 48.65% (18/37) in 2011-2012 to 28.10% (43/153) in 2013-2020 ( χ2=9.38, P=0.002). Conclusions:Compared to from 2011 to 2012, both the positivity rate and antimicrobial resistance prevalence of LP in public aqueous environments of Shanghai exhibited an overall decline from 2013 to 2020. The predominant types of LP were serotype Lp1 and sequence type ST752, with notable high-level resistance to azithromycin. Measures as enhancing the enforcement of water safety regulations and prioritizing surveillance of azithromycin resistance in LP were recommended to mitigate public health risks.

Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.

Objective Exploring the components of complex scenarios of healthcare surges triggered by major epidemics to provide a theorical basis for building resilience in healthcare organizations.Methods A hybrid analysis method is used to summarize macro-meso-micro multi-level and multi-source heterogeneous information,extract the elements of complex scenarios of medical surge and evaluate the rationality.Fault Tree Analysis method is used to clarify the logical relationship between various scenario elements and construct scenario reasoning paths.Results 10 scenario states,11 disaster-bearing,24 emergency management and 23 scenario results are summarized and extracted to form the key elements of complex surge scenarios.Among them,M4 expansion and coordinated scheduling of key positions,B2 conventional drug inventory emergency/insufficient core treatment drugs,B emergency medical material transportation breakage,S3 disease symptom spectrum shift to severe disease,R13 prevention and control awareness laxity,and M5 media information dissemination management are the key driving factors that promote a major turning point in the scenario.The most positive scenario result is the orderly operation of the medical service system,and the most negative scenario result is the paralysis of the medical service system.Conclusion Medical institutions need to improve emergency plans based on the complex evolution scenarios of medical surges and agile governance capabilities targeting key turning points,focus on dynamically expanding and scheduling personnel in key positions,strengthen material rotation and reserve mechanisms,maintain smooth emergency logistics channels,and improve efficient management of media and public opinion,so as to comprehensively improve overall resilience.