BACKGROUND:Bone tissue loss caused by tumors and trauma can have an adverse effect on postoperative rehabilitation.Therefore,scaffold materials are usually implanted during treatment.However,the existing implant materials are relatively simple and lack antibacterial properties.Early implantation may lead to iatrogenic autoinfection and have an adverse effect on osteogenesis.OBJECTIVE:To construct a KR-12-a5 polypeptide-nanohydroxyapatite-small intestinal submucosa composite scaffold and evaluate its feasibility as a material for promoting bone defect repair.METHODS:The small intestinal submucosa scaffold and the small intestinal submucosa scaffold containing 25,50,and 100 mg/mL nanohydroxyapatite(referred to as nHA-SIS scaffold)were prepared by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride/N-hydroxysuccinimide cross-linking method.The appropriate scaffold was screened for subsequent experiments by mechanical property testing.The antibacterial properties of KR-12-a5 polypeptide solution against Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum were detected.The nHA-SIS scaffolds were immersed in 250,500,and 1 000 μg/mL KR-12-a5 peptide solutions for 24 hours,and then freeze-dried to obtain peptide-loaded nanohydroxyapatite-porcine small intestinal submucosa composite scaffolds(denoted as P-nHA-SIS scaffolds).The sustained-release properties of the three groups of scaffolds were characterized.The nHA-SIS scaffolds and the three groups of P-nHA-SIS scaffolds were co-cultured with Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum for 24 hours or 48 hours.The scaffolds with strong antibacterial ability were screened by live and dead bacteria staining and scanning electron microscopy for subsequent experiments.The degradation properties and water absorption rates of the uncross-linked small intestinal submucosa scaffolds,cross-linked small intestinal submucosa scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were characterized.The extracts of cross-linked small intestinal submucosal scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were co-cultured with MC3T3-E1 cells.CCK-8 assay and live-dead cell staining were performed.The effects of the extracts of the three scaffolds on the migration of MC3T3-E1 cells were detected by Transwell chamber assay.RESULTS AND CONCLUSION:(1)The elastic modulus and compressive strength of 25,50,and 100 mg/mL nHA-SIS scaffolds were higher than those of small intestinal submucosal scaffolds(P＜0.05),among which the elastic modulus and compressive strength of 25 mg/mL nHA-SIS scaffolds were the highest,and this group of scaffolds were selected for subsequent experiments to load peptides.(2)KR-12-a5 peptide had strong antibacterial activity against common bacteria in bone defects(Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum).The three groups of P-nHA-SIS scaffolds all had sustained release properties.With the increase of peptide mass concentration,the antibacterial property of P-nHA-SIS scaffold was enhanced.Among them,the P-nHA-SIS scaffold loaded with 500 μg/mL peptide had achieved a satisfactory antibacterial effect,and this group of scaffolds would be selected in the future.(3)The degradation rate of the three groups of cross-linked scaffolds was lower than that of the uncross-linked scaffolds,and the water absorption rate was greater than that of the uncross-linked scaffolds.P-nHA-SIS scaffolds could promote the proliferation and migration of MC3T3-E1 cells without affecting the activity of MC3T3-E1 cells.(4)The results show that P-nHA-SIS scaffolds have strong antibacterial properties and the ability to promote the proliferation and migration of MC3T3-E1 cells,and are expected to be used in bone defect repair.

BACKGROUND:Bone tissue loss caused by tumors and trauma can have an adverse effect on postoperative rehabilitation.Therefore,scaffold materials are usually implanted during treatment.However,the existing implant materials are relatively simple and lack antibacterial properties.Early implantation may lead to iatrogenic autoinfection and have an adverse effect on osteogenesis.OBJECTIVE:To construct a KR-12-a5 polypeptide-nanohydroxyapatite-small intestinal submucosa composite scaffold and evaluate its feasibility as a material for promoting bone defect repair.METHODS:The small intestinal submucosa scaffold and the small intestinal submucosa scaffold containing 25,50,and 100 mg/mL nanohydroxyapatite(referred to as nHA-SIS scaffold)were prepared by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride/N-hydroxysuccinimide cross-linking method.The appropriate scaffold was screened for subsequent experiments by mechanical property testing.The antibacterial properties of KR-12-a5 polypeptide solution against Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum were detected.The nHA-SIS scaffolds were immersed in 250,500,and 1 000 μg/mL KR-12-a5 peptide solutions for 24 hours,and then freeze-dried to obtain peptide-loaded nanohydroxyapatite-porcine small intestinal submucosa composite scaffolds(denoted as P-nHA-SIS scaffolds).The sustained-release properties of the three groups of scaffolds were characterized.The nHA-SIS scaffolds and the three groups of P-nHA-SIS scaffolds were co-cultured with Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum for 24 hours or 48 hours.The scaffolds with strong antibacterial ability were screened by live and dead bacteria staining and scanning electron microscopy for subsequent experiments.The degradation properties and water absorption rates of the uncross-linked small intestinal submucosa scaffolds,cross-linked small intestinal submucosa scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were characterized.The extracts of cross-linked small intestinal submucosal scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were co-cultured with MC3T3-E1 cells.CCK-8 assay and live-dead cell staining were performed.The effects of the extracts of the three scaffolds on the migration of MC3T3-E1 cells were detected by Transwell chamber assay.RESULTS AND CONCLUSION:(1)The elastic modulus and compressive strength of 25,50,and 100 mg/mL nHA-SIS scaffolds were higher than those of small intestinal submucosal scaffolds(P＜0.05),among which the elastic modulus and compressive strength of 25 mg/mL nHA-SIS scaffolds were the highest,and this group of scaffolds were selected for subsequent experiments to load peptides.(2)KR-12-a5 peptide had strong antibacterial activity against common bacteria in bone defects(Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum).The three groups of P-nHA-SIS scaffolds all had sustained release properties.With the increase of peptide mass concentration,the antibacterial property of P-nHA-SIS scaffold was enhanced.Among them,the P-nHA-SIS scaffold loaded with 500 μg/mL peptide had achieved a satisfactory antibacterial effect,and this group of scaffolds would be selected in the future.(3)The degradation rate of the three groups of cross-linked scaffolds was lower than that of the uncross-linked scaffolds,and the water absorption rate was greater than that of the uncross-linked scaffolds.P-nHA-SIS scaffolds could promote the proliferation and migration of MC3T3-E1 cells without affecting the activity of MC3T3-E1 cells.(4)The results show that P-nHA-SIS scaffolds have strong antibacterial properties and the ability to promote the proliferation and migration of MC3T3-E1 cells,and are expected to be used in bone defect repair.

Objective: To investigate the status of antibiotic exposure in third grade primary school students in Shenzhen,so as to provide evidence for the scientific management of antibiotic use and reduction of population health risks. Methods: From 1 September to 30 October 2021, 200 third grade students from 8 primary schools in Luohu District of Shenzhen were selected by cluster random sampling as research subjects. The body composition was measured, urine samples were collected, and the contents of 35 antibiotics in the samples were detected by mass spectrometry. Relevant dietary habit information of the subjects was collected via questionnaires. The Chi square test was used to compare the detection rate of antibiotics among different genders and weight grades. The Logistic regression model was adopted to evaluate the correlation between the target antibiotic detection rate and dietary habits. Results: At least one type of antibiotic was detected in 198 of the subjects with an overall detection rate of 99.0% . Among the 35 target antibiotics, 23 were detected with detection rates ranging from 0.5%-69.5%. Quinolones had the highest detection rate of 86.5% , followed by macrolides and sulfonamides with detection rates of 77.5% and 76.5%, respectively. The detection rate of antibiotics was 98.3% in boys and 100.0% in girls with no statistically significant difference ( χ 2=1.35, P >0.05). The detection rates of quinolones, macrolides, and sulfonamides varied significantly among children with different BMI categories ( χ 2=38.18, 12.45, 9.76 , all P <0.05). The multivariate Logistic regression model analysis showed that the macrolide detection rate was affected by genders( OR =0.42) and the sulfonamide detection rate was significantly correlated with the frequency of dairy product consumption and being overweight( OR =2.01)(both P <0.05). Enrofloxacin was associated with the weekly consumption frequency of livestock meat such as pork, beef and mutton, as well as the weekly consumption frequency of poultry meat such as chicken, duck and goose ( OR = 2.81,2.17,both P <0.05). Trimethoprim was associated with the weekly frequency of drinking pure milk ( OR =5.49, P < 0.05 ). Conclusions Third grade primary school students in Shenzhen are generally exposed to low dose antibiotics. Macrolides, quinolones, and sulfonamides may be associated with the risk of obesity in primary school students.

Objective To investigate and compare the epidemiological characteristics of common respiratory viruses among influenza-like illness(ILI)and severe acute respiratory infection(SARI)cases in Huzhou,Zhejiang Province before and after the COVID-19 pandemic,so as to provide a basis for formulating and adjusting the prevention and control strategies for viral respiratory infectious diseases.Methods ILI and SARI cases at two influenza surveillance sentinel hospitals in Huzhou and had throat swab samples collected during Nov 2017 to Feb 2020(pre-COVID-19 pandemic period)and Dec 2022 to Apr 2024(post-COVID-19 mitigation phase)were selected as the participants.Seven common viral respiratory pathogens were tested,including influenza A virus(H1N1 and H3N2 subtypes),influenza B virus(Victoria lineage,FluB),respiratory syncytial virus(RSV),rhinovirus(HRV),adenovirus(ADV),and severe acute respiratory syndrome coronavirus-2(SARS-CoV-2).The positive rates of respiratory pathogens before and after the COVID-19 pandemic were compared across different age groups and different time.Results A total of 7 948 ILI samples and 2 294 SARI samples were included.The overall positive rate of ILI samples increased from 33.6%to 47.1%,primarily due to the increase in influenza and COVID-19 infections;the overall positive rate of SARI samples decreased from 31.4%to 24.8%,mainly due to the reduction in HRV and ADV infections.During the post-COVID-19 mitigation phase,SARS-CoV-2(22.1%),H3N2(12.7%),and FluB(6.0%)were the primary pathogens in ILI samples,while RSV(7.1%),H3N2(5.3%),and HRV(4.5%)dominated in SARI samples.During the post-COVID-19 mitigation phase,the influenza virus circulation period was shortened.Before the COVID-19 pandemic,RSV was mainly detected in autumn and winter,while during the post-COVID-19 mitigation phase,out-of-season RSV epidemics were observed in spring and summer.Co-infection rate in ILI cases increased significantly in the post-COVID-19 mitigation phase,predominantly consisting of co-infections of COVID-19 and influenza A virus,while co-infection rate in SARI cases showed a decline.Conclusion We found important epidemiological changes in respiratory viruses in Huzhou during the post-COVID-19 mitigation phase compared to pre-COVID-19 period,including increased positive rates of influenza and COVID-19,and disruptions to the seasonal patterns of influenza and RSV.The prevention and control strategies should be adjusted in a timely manner based on the monitoring data.

Objective:To investigate the effects of different BMI classifications on rehabilitation outcomes and complications after total knee arthroplasty(TKA).Methods:Clinical data of 88 patients who underwent TKA in our hospital from January 2022 to June 2024 were retrospectively analyzed.According to the World Health Organization(WHO)BMI standards,patients were divided into normal weight group(18.5 ≤BMI＜24.9 kg/m2),overweight group(25.0≤BMI＜29.9 kg/m2),mild obesity group(30.0≤BMI＜34.9 kg/m2),and severe obesity group(BMI≥35.0 kg/m2).Baseline data,operation time,intraoperative blood loss,hospital stay,postoperative knee function scores,pain scores,range of motion(ROM),and incidence of complications were compared among groups.Results:With the increase of BMI,operation time was prolonged,intraoperative blood loss increased,and hospital stay extended,with statistically significant differences(P＜0.05).At 3-month and 6-month follow-ups,Knee Society Score(KSS)and Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)showed that functional recovery decreased with increasing BMI(P＜0.05).Regarding postoperative complications,the incidence of poor incision healing,infection,and deep vein thrombosis(DVT)in the obese groups was significantly higher than in the normal weight and overweight groups(P＜0.05).Conclusion:BMI is an important factor affecting rehabilitation outcomes and complications after TKA.Patients with high BMI have slower functional recovery and higher complication rates.For patients with high BMI,preoperative weight loss and individualized rehabilitation programs should be considered to improve TKA prognosis.

Objective To explore the changes in neural activity in patients with type 2 diabetes mellitus(T2DM)and their corre-lation with executive function,and to analyze the neural mechanisms underlying the decline in executive function in T2DM patients.Methods Thirty-one T2DM patients(T2DM group)and thirty-two healthy controls(HC)(HC group)matched for body mass index(BMI)underwent resting-state functional magnetic resonance imaging(rs-fMRI)scans and N-back task tests were included.Differ-ences in the amplitude of low-frequency fluctuation(ALFF),regional homogeneity(ReHo),and seed-based functional connectivity(FC)between the two groups were compared,and partial correlation analyses were performed between the difference results and N-back task performance.Results The T2DM group showed prolonged reaction time(RT)in the 1-back and 2-back tasks.T2DM patients exhibited increased ALFF in the bilateral caudate nucleus,left medial superior frontal gyrus,and right postcentral gyrus,as well as elevated ReHo in the right putamen.FC analysis revealed significant alterations in FC between the caudate nucleus,putamen,and multiple brain regions in T2DM patients,with some of these FC changes significantly correlated with RT and accuracy(ACC)in the N-back task.Conclusion The decline in executive function in T2DM patients may be associated with abnormal neural activity in brain regions such as the striatum,salience network,and frontoparietal control network.FC further decreases under increased cognitive load.These findings provide evidence for the study of the neural mechanisms of executive function impairment in T2DM patients.

Implementing the reform of outpatient mutual-aid is a crucial measure to improve China's medical security system.Based on the policy diffusion theory,we took 228 prefecture-level cities across the country as the research objects and used the event history method to analyze the diffusion mode and influencing factors of the general outpatient pooling policy for employees'basic medical insurance,and divided into three types:the type of reducing the stock of Medical Savings Accounts(MSA),the welfare increment type I and type II for separate analysis.We found that the diffusion of the general outpatient pooling policy presented an"S"-shaped curve over time,and was mainly horizontally diffused in space,with a neighboring effect and a regional demonstration effect.The type of reducing the stock of MSA policy diffuses horizontally;the welfare increment type I is mainly horizontal diffusion,supplemented by vertical diffusion;the welfare increment type II is not affected by the pressure from higher-level governments,and mainly adopts the horizontal diffusion mode.In terms of the influencing factors of policy diffusion,the diffusion of the general outpatient pooling policy was affected by multiple factors such as policy issues,legitimacy,and government capacity.The diffusion of the type of reducing the stock of MSA policy was not affected by the pressure from higher-level governments,but was influenced by policy issues and government capacity.The diffusion of the welfare increment type I policy was most affected by policy issues,and the welfare increment type II was most affected by government capacity.

Objective:To investigate the effects of different BMI classifications on rehabilitation outcomes and complications after total knee arthroplasty(TKA).Methods:Clinical data of 88 patients who underwent TKA in our hospital from January 2022 to June 2024 were retrospectively analyzed.According to the World Health Organization(WHO)BMI standards,patients were divided into normal weight group(18.5 ≤BMI＜24.9 kg/m2),overweight group(25.0≤BMI＜29.9 kg/m2),mild obesity group(30.0≤BMI＜34.9 kg/m2),and severe obesity group(BMI≥35.0 kg/m2).Baseline data,operation time,intraoperative blood loss,hospital stay,postoperative knee function scores,pain scores,range of motion(ROM),and incidence of complications were compared among groups.Results:With the increase of BMI,operation time was prolonged,intraoperative blood loss increased,and hospital stay extended,with statistically significant differences(P＜0.05).At 3-month and 6-month follow-ups,Knee Society Score(KSS)and Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)showed that functional recovery decreased with increasing BMI(P＜0.05).Regarding postoperative complications,the incidence of poor incision healing,infection,and deep vein thrombosis(DVT)in the obese groups was significantly higher than in the normal weight and overweight groups(P＜0.05).Conclusion:BMI is an important factor affecting rehabilitation outcomes and complications after TKA.Patients with high BMI have slower functional recovery and higher complication rates.For patients with high BMI,preoperative weight loss and individualized rehabilitation programs should be considered to improve TKA prognosis.

Tovorafenib has been approved by the U.S.Food and Drug Administration(FDA)for the treatment of patients 6 months of age and older with relapsed or refractory pediatric low-grade glioma(LGGs)harboring the serine threonine kinae v-RAF murine sarcoma viral oncogene homologue B1(BRAF)fusion or rearrangement,or BRAV600E mutation.Tovorafenib is an oral,greater brain-penetrant,selective,type Ⅱ RAF inhibitor which has potent activity against both oncogenic BRAF fusions and BRAFV600E mutations.Most tumors have been showed some degree of shrinkage.The mechanism of action,pharmacodynamics,pharmacokinetics,clinical study and safety were introduced.

A quadruplex RT-qPCR method was developed for rapid identification and diagnosis of transmissible gastroenteritis virus(TGEV)of swine,porcine epidemic diarrhea virus(PEDV),porcine deltacorona virus(PDCoV),and porcine rotavirus type A(PoRVA).The full-length sequences of PEDV(77 strains),TGEV(63 strains),PDCoV(17 strains)that are prevalent in China,as well as the 85 VP6 gene sequences of PoRVA,were downloaded from the NCBI database for homology analysis.Based on the relatively conserved sequences,the corresponding primers and probes for each virus were designed and used to establish the quadruplex RT-qPCR method.After optimization of the probes and the reaction conditions,the specificity,sensitivity,and repeatability were determined.Using the established method,109 clinical samples of diarrhea were tested and further compared with the results by standard method.The results showed that the quadruplex RT-qPCR method established in this experiment has good amplification effect,with the C,value linearly correlated with the copies of templates(R2＞0.99).Specificity assay demonstrated that the quadruplex RT-qPCR method can identify TGEV,PEDV,PDCoV,PRoVA strains,and do not de-tect African swine fever virus(ASFV),porcine circovirus type 2(PCV2),porcine reproductive and respiratory syndrome virus(PRRSV),classical swine fever virus(CSFV),pseudorabies virus(PRV)and other epidemic viruses.Sensitivity assay showed that the detection limits for TGEV,PEDV,PDCoV and PoRVA were 10,20,20 and 50 copies/μL,respectively.The method exhibits excellent reproducibility,with coefficients of variation(Cv)for both intra-and inter-assay repli-cates being less than 1％.Detection of 109 samples of diarrhea by this method yielded the coinci-dence rate of 100％with the industry standard,indicating high practical applicability.The devel-oped method possesses the advantages of strong strain compatibility,high sensitivity,strong speci-ficity,good repeatability and stability.It is suitable for virus diagnosis and large-scale clinical sam-ple testing,providing technical support for disease prevention and control as well as epidemiologi-cal investigation.