BACKGROUND:Promoting skin wound healing is a huge challenge facing global public health.To promote faster and higher-quality wound healing,it is necessary to explore more advantageous dressings to address this problem.OBJECTIVE:To investigate the hemostatic properties of acellular dermal matrix hydrogel and its effect on skin wound healing.METHODS:(1)Acellular dermal matrix hydrogel was prepared,and the differences in microscopic morphology and main components between it and acellular dermal matrix were analyzed.(2)Acellular dermal matrix hydrogel and chitosan hydrogel were used to cover the femoral artery puncture site of rats,and the bleeding quality and coagulation time were recorded.Acellular dermal matrix hydrogel and chitosan hydrogel were mixed with rat anticoagulated blood,and the coagulation index within 30 minutes was detected.(3)A full-thickness skin defect model with a diameter of 12 mm was made on the back of 18 SD rats,and they were randomly divided into 3 groups,with 6 rats in each group:the model group used PBS to clean the wound,and the control group and the experimental group used chitosan hydrogel and acellular dermal matrix hydrogel to cover the wound,respectively.The hydrogel dressing was changed every day,and the treatment was continued for 14 days,and the wound healing was observed.On day 3 after modeling,immunofluorescence staining of inducible nitric oxide synthase(M1 macrophages)and CD206(M2 macrophages)was performed on the wound surface.On day 14 after modeling,hematoxylin-eosin staining,Masson staining,and CD31 immunohistochemical staining were performed on the wound surface.RESULTS AND CONCLUSION:(1)Scanning electron microscopy revealed that the acellular dermal matrix hydrogel had a porous structure,and the Fourier transform infrared spectrum showed that it had the same main components as the acellular dermal matrix.(2)Both acellular dermal matrix hydrogel and chitosan hydrogel had obvious hemostatic ability in vivo.In the in vitro coagulation experiments,the coagulation index of acellular dermal matrix hydrogel was significantly higher than that of chitosan hydrogel.(3)In the rat skin full-thickness defect model,both acellular dermal matrix hydrogel and chitosan hydrogel could improve the wound healing rate.Hematoxylin-eosin and Masson staining results showed that acellular dermal matrix hydrogel could reduce the infiltration of inflammatory cells in the center of the wound.Both acellular dermal matrix hydrogel and chitosan hydrogel could decrease scar width and increase collagen deposition rate.CD31 immunohistochemical staining results showed that both hydrogels could promote angiogenesis in the wound site.Immunofluorescence staining results showed that both hydrogels could reduce the proportion of M1 macrophages and increase the proportion of M2 macrophages,and the effect of acellular dermal matrix hydrogel was stronger than that of chitosan hydrogel.(4)The results show that the acellular dermal matrix hydrogel has good hemostatic properties and the ability to promote wound healing.

BACKGROUND:Promoting skin wound healing is a huge challenge facing global public health.To promote faster and higher-quality wound healing,it is necessary to explore more advantageous dressings to address this problem.OBJECTIVE:To investigate the hemostatic properties of acellular dermal matrix hydrogel and its effect on skin wound healing.METHODS:(1)Acellular dermal matrix hydrogel was prepared,and the differences in microscopic morphology and main components between it and acellular dermal matrix were analyzed.(2)Acellular dermal matrix hydrogel and chitosan hydrogel were used to cover the femoral artery puncture site of rats,and the bleeding quality and coagulation time were recorded.Acellular dermal matrix hydrogel and chitosan hydrogel were mixed with rat anticoagulated blood,and the coagulation index within 30 minutes was detected.(3)A full-thickness skin defect model with a diameter of 12 mm was made on the back of 18 SD rats,and they were randomly divided into 3 groups,with 6 rats in each group:the model group used PBS to clean the wound,and the control group and the experimental group used chitosan hydrogel and acellular dermal matrix hydrogel to cover the wound,respectively.The hydrogel dressing was changed every day,and the treatment was continued for 14 days,and the wound healing was observed.On day 3 after modeling,immunofluorescence staining of inducible nitric oxide synthase(M1 macrophages)and CD206(M2 macrophages)was performed on the wound surface.On day 14 after modeling,hematoxylin-eosin staining,Masson staining,and CD31 immunohistochemical staining were performed on the wound surface.RESULTS AND CONCLUSION:(1)Scanning electron microscopy revealed that the acellular dermal matrix hydrogel had a porous structure,and the Fourier transform infrared spectrum showed that it had the same main components as the acellular dermal matrix.(2)Both acellular dermal matrix hydrogel and chitosan hydrogel had obvious hemostatic ability in vivo.In the in vitro coagulation experiments,the coagulation index of acellular dermal matrix hydrogel was significantly higher than that of chitosan hydrogel.(3)In the rat skin full-thickness defect model,both acellular dermal matrix hydrogel and chitosan hydrogel could improve the wound healing rate.Hematoxylin-eosin and Masson staining results showed that acellular dermal matrix hydrogel could reduce the infiltration of inflammatory cells in the center of the wound.Both acellular dermal matrix hydrogel and chitosan hydrogel could decrease scar width and increase collagen deposition rate.CD31 immunohistochemical staining results showed that both hydrogels could promote angiogenesis in the wound site.Immunofluorescence staining results showed that both hydrogels could reduce the proportion of M1 macrophages and increase the proportion of M2 macrophages,and the effect of acellular dermal matrix hydrogel was stronger than that of chitosan hydrogel.(4)The results show that the acellular dermal matrix hydrogel has good hemostatic properties and the ability to promote wound healing.

Prescription optimization is a crucial aspect in the study of traditional Chinese medicine （TCM） compounds. In recent years， the introduction of mathematical methods， data mining techniques， and artificial neural networks has provided new tools for elucidating the compatibility rules of TCM compounds. The study of TCM compounds involves numerous variables， including the proportions of different herbs， the specific extraction parts of each ingredient， and the interactions among multiple components. These factors together create a complex nonlinear dose-effect relationship. In this context， it is essential to identify methods that suit the characteristics of TCM compounds and can leverage their advantages for effective application in new drug development. This paper provided a comprehensive review of the cutting-edge optimization experimental design methods applied in recent studies of TCM compound compatibilities. The key technical issues， such as the optimization of source material selection， dosage optimization of compatible herbs， and multi-objective optimization indicators， were discussed. Furthermore， the evaluation methods for component effects were summarized during the optimization process， so as to provide scientific and practical foundations for innovative research in TCM and the development of new drugs based on TCM compounds.

Objective To analyze the epidemiological characteristics of norovirus outbreaks in Haidian District, Beijing, and to provide a reference for epidemic prevention and control. Methods Descriptive epidemiological methods were used to organize and statistically analyze the norovirus outbreak data reported from 2016 to 2022. Results A total of 26 outbreaks of norovirus were reported in Haidian District, with a total of 1595 cases and an attack rate M (Q_R) of 8.23 (16.33)%. There were 24 cases of norovirus type GII (92.31%), 1 case of type GI (3.85%), and 1 case of mixed infection of virus type GI/GII (3.85%). The highest number of reported outbreaks occurred in March and April, with 17 cases, accounting for 65.38%. The highest number of reported cases was in November and December, with 785 cases, accounting for 44.92%. The case age M (Q_R) was 18 (14) years old. The detection rate of positive samples in different age groups had statistical significance（χ²=12.021, P=0.007). The 26 outbreaks were mainly distributed in collective units such as schools, preschool institutions, and enterprises and institutions. There were a total of 11 outbreaks related to foodborne transmission, with 923 cases, accounting for 57.87%. Diarrhea was positively correlated with the age of the cases (r_s=0.572, P<0.001), while vomiting was negatively correlated with the age of the cases (r_s=-0187, P<0.001). The time interval between the onset of acute gastroenteritis symptoms in the first case and the reporting of the epidemic was positively correlated with the duration of the epidemic (r_s=0.586, P=0.002). Conclusion It is necessary to strengthen the prevention and control of norovirus in schools (primary and secondary schools and colleges), strictly implement health monitoring and regular screening for kitchen workers, carry out publicity and education, detect cases as early as possible, report the epidemic in a timely manner, and effectively reduce the scale of the epidemic and prevent its spread.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Metabolic disorders and immunosuppression exist in peripartal cows,and glutamine(GLN)has the potential efficacy to improve the negative energy balance(NEB)and the function of neutrophil(polymorphonuclear granulocyte,PMN)in peripartal cows.The aim of the present study was to investigate the effects of supplementation with rumen-protected GLN on the metabo-lism and the phagocytosis function of PMN in peripartal cows.Twenty Chinese Holstein cows with similar age,parity,body condition score and expected date of delivery were selected and divided into CON(n=10,fed basal diet)and GLN groups(n=10,supplemented with 180 g/d of rumen-protected GLN).During the test period of 42 d,blood samples were collected at-21,-14,-7,0,7,14 and 21 d.Milk production was recorded at 7,14 and 21 d,respectively.The results showed that:serum GLN concentrations in peripartal cows continued to decrease until they increased after 7 d postpartum,suggesting that peripartal cows may be in a state of GLN deficiency.The serum GLN content of the cows increased significantly(P＜0.05)from-7 to 21 d after GLN supple-mentation,indicating that supplementation was effective.The blood glucose concentration of peri-partal cows increased on the day of parturition but decreased postpartum,and the concentrations of non-esterified fatty acid(NEFA)and β-hydroxybutyrate(BHBA)in the blood increased postpar-tum,which indicated that peripartal cows had a physiological NEB.Blood glucose concentration in-creased significantly(P＜0.01)at-7,14 and 21 d after GLN supplementation,and blood concen-trations of NEFA and BHBA decreased significantly(P＜0.01)postpartum,suggesting that peri-partal cows had a NEB alleviated by GLN supplementation.Serum malondialdehyde(MDA)con-centration of periparturient cow peaked on the day of parturition but declined postpartum,and the concentration of MDA reached a peak on the day of delivery but declined postpartum,and the total antioxidant capacity(T-AOC)level continued to decline until it increased on the day of parturi-tion,indicating that peripartal cows were in a state of oxidative stress.Serum MDA concentration significantly decreased(P＜0.05)and serum T-AOC level significantly increased(P＜0.05)after GLN supplementation,indicating that antioxidant capacity of peripartal cows was improved by GLN supplementation.The concentration of serum pro-inflammatory factor IL-β peaked on the day of parturition and then decreased,the concentration of TNF-α peaked on the day of parturition and then decreased,and the concentration of anti-inflammatory factor IL-10 continued to decrease,which indicated that there was an inflammatory reaction in the cows during the periparturient peri-od.However,the levels of IL-1β on the day of delivery and postpartum decreased significantly(P＜0.01),the levels of TNF-α decreased(P＜0.05),and the levels of IL-10 increased significantly(P＜0.01)throughout the peripartum period,which indicated that GLN supplementation im-proved the anti-inflammatory ability of periparturient dairy cows.The phagocytosis function of PMN in peripartal cows was significantly reduced from-14 d to the day of parturition(P＜0.01),and the phagocytosis function of neutrophils was significantly enhanced after GLN supple-mentation at-14(P＜0.05),14 and 21 d(P＜0.01),which indicated that intrinsic immune func-tion of peripartal cows was enhanced by supplementation of GLN.GLN supplementation did not significantly affect milk production of cows at three weeks postpartum.In conclusion,supplemental rumen-protected GLN alleviated NEB,alleviated systemic oxidative stress and inflammatory re-sponse,and enhanced phagocytosis of PMN in peripartal cows,which has some potential for clini-cal application.

Sacroiliac complex injuries are commonly seen in high-energy pelvic fractures. The injuries make a big difference in treatment patterns due to the diverse injury types, posing considerable challenges in formulating optimal treatment strategies, and hence are persistent clinical difficulties in orthopedic trauma. The clinical management of sacroiliac complex injuries presents several key challenges such as a non-negligible rate of missed diagnoses in associated vascular and visceral injuries, absence of standardized protocols for surgical approaches and reduction-fixation strategies across different injury patterns, and ongoing controversies regarding surgical indications and optimal timing for patients combined with concomitant lumbosacral plexus injuries. Currently, no systematic clinical guidelines are available for the diagnosis and treatment of sacroiliac complex injuries both domestically and internationally. To this end, the Pelvic and Acetabular Surgery Group, Orthopedic Branch, China International Exchange and Promotive Association for Medical and Health Care and Orthopedic Physician Branch, Chinese Medical Doctor Association organized a panel of domestic experts in the field to develop the Clinical guideline for the diagnosis and treatment of sacroiliac complex injuries ( version 2025), based on evidence-based medicine and adhering to the principles of scientific rigor, clinical applicability, and innovation. These guidelines provided 11 recommendations covering diagnosis, therapeutic principles and techniques, management protocols for lumbosacral plexus injuries, outcome evaluation, and postoperative rehabilitation pathways, etc., aiming to standardize the clinical management of sacroiliac complex injuries.