ObjectiveThis study aims to investigate the regulatory effects of microcapsules with different matrix stiffness on the survival, proliferation, adhesion, and osteogenic differentiation of mesenchymal stem cells (MSCs), to further explore the relationship between matrix stiffness and MSCs osteogenic behavior, and to evaluate the in vivo histological responses and osteogenic-related protein expression of the microcapsules using an animal subcutaneous implantation model. MethodsIn this study, three-dimensional carbon nanofiber (CNF)/sodium alginate (SA) microcapsules with different matrix stiffness were constructed. By adjusting the CNF content, three groups of microcapsules with stiffness values of 27.05, 35.90, and 52.40 kPa were prepared, and their physicochemical properties, including morphology, mechanical properties, particle size, chemical structure, and degradation properties, were characterized. The effects of these microcapsules with different stiffness on the survival, adhesion, and osteogenic differentiation of MSCs were evaluated. Live/dead staining was used to observe cell survival and distribution in the microcapsules, while alkaline phosphatase (ALP) activity and the expression of osteopontin (OPN) and osteocalcin (OCN) were examined to assess osteogenic differentiation. Immunofluorescence staining was further performed to observe the expression of Yes-associated protein (YAP) and integrin β1 under different stiffness conditions. In addition, a rat subcutaneous implantation model was used to evaluate the in vivo tissue compatibility of the microcapsules. Histological staining and immunohistochemical analysis were carried out to examine local tissue responses and the expression of osteogenic-related proteins. ResultsThe results showed that all three groups of microcapsules exhibited regular and uniform morphology and similar particle size, and all groups showed good degradability. Except for the differences in mechanical properties, no obvious differences were found in the other physicochemical properties among the three groups. Live/dead staining indicated that all groups of microcapsules had good cytocompatibility. MSCs in the low-stiffness group were mostly round, whereas cells in the medium- and high-stiffness groups showed more obvious spreading. Higher matrix stiffness was more favorable for MSC adhesion, growth, and survival. ALP staining and quantitative analysis showed that ALP activity increased significantly with increasing matrix stiffness. The expression of the osteogenic-related proteins OPN and OCN also increased with increasing stiffness, and the high-stiffness group showed the strongest positive signals. Immunofluorescence results further indicated that YAP and integrin β1 fluorescence signals tended to increase in MSCs with increasing matrix stiffness, suggesting that matrix stiffness may influence MSC osteogenic differentiation through stiffness-related cell adhesion and mechanotransduction. In vivo experiments showed that all three groups of microcapsules exhibited good histocompatibility after subcutaneous implantation, although different degrees of degradation and local tissue response were observed. Immunohistochemical analysis showed that the expression levels of OPN and OCN increased with increasing matrix stiffness, and the high-stiffness group exhibited higher expression of these osteogenic-related proteins. ConclusionCNF endows SA microcapsules with tunable matrix stiffness. While maintaining good biocompatibility, the high-stiffness microenvironment can effectively promote the adhesion and osteogenic differentiation of MSCs, accompanied by increased ALP activity and enhanced OPN and OCN expression. The increased YAP and integrin β1 fluorescence signals in the high-stiffness group further indicate that matrix stiffness is closely related to cellular mechanical responses. These findings provide a three-dimensional cell carrier with potential application value for MSC delivery and bone tissue regeneration based on mechanical microenvironment regulation.

Risks of food safety induced by small molecule drug residues in animal food and environment have become an increasing public concern,so it is necessary to develop highly sensitive and easy-to-operate techniques to detect small molecules.Herein,a metasurface plasma resonance(MetaSPR)sensor chip coupled with gold nanoparticles(AuNPs)was developed for detection of enrofloxacin(ENR)based on competitive immunoassay.The detection range of the sensor for ENR was 0.025-3.2 ng/mL,and the detection limit(3σ)was 20 pg/mL.The biosensor showed excellent performance including high selectivity,good stability,ease to operate and high throughput,etc.The developed method was applied to detection of ENR residues in real samples,with recoveies of 96.0% -105.0%.The proposed sensing strategy provided new technique reference for detection of other small molecules in the field of residue analysis in food safety and environment monitoring.

Objective To verify the efficacy of a domestic human DNA quantification kit based on real-time fluorescence quantitative PCR in detecting the total human DNA concentration,male DNA concen-tration in mixed male/female DNA samples,the degree of DNA degradation and inhibitor tolerance.Methods Samples with different concentrations,different male/female ratios,different concentrations of inhibitors,and different degradation degrees were tested using the domestic human DNA quantification kit based on real-time fluorescence quantitative PCR.This kit was compared with a similar product on the market and was applied to the detection of DNA from real cases.Results This human DNA quan-tification kit can effectively detect human DNA as low as 0.001 65 ng/μL,and 6.25 pg/μL of male DNA in mixed samples with a male-to-female ratio of 1∶15 000.Even when the sample contains as high as 400 ng/μL of humic acid or 1 000 μmol/L of hemin alone,the DNA concentration can still be accurately detected.The degradation index can effectively characterize the degradation degree of the sample.This kit has been successfully applied in forensic practice.Conclusion This human DNA quan-tification kit is accurate and reliable in detection.It can accurately reflect the degradation of DNA and inhibitor tolerance.It has good performance in quantitative accuracy,determination of the male/female ratio in mixed samples,and inhibitor tolerance.It has application potential in forensic case examination.

Objective:To evaluate the efficacy of remimazolam-based anesthesia in daytime laparoscopic cholecystectomy.Methods:In this multicenter, non-inferiority, randomized controlled trial, 300 American Society of Anesthesiologists Physical Status classification Ⅰ or Ⅱ patients of either sex, aged 18-60 yr, with body mass index of 18-28 kg/m 2, who underwent daytime laparoscopic cholecystectomy under general anesthesia with tracheal intubation at Sir Run Run Shaw Hospital Affiliated to Zhejiang University School of Medicine, the Fourth Affiliated Hospital of Zhejiang University School of Medicine, Jinhua Hospital Affiliated to Zhejiang University School of Medicine, Hangzhou First People′s Hospital Affiliated to Westlake University School of Medicine, Ningbo No. 2 Hospital, and the Second Affiliated Hospital of Nanchang University from August 2021 to August 2023, were selected and divided into 2 groups ( n=150 each) using a random number table method: remimazolam group (R group) and propofol group (P group). Anesthesia was induced as follows: Sufentanil was intravenously injected at a rate of 0.5 μg/kg, remimazolam was intravenously injected at a rate of 0.3 mg/kg in group R, propofol was intravenously injected at a rate of 2.0-2.5 mg/kg in group P, and cisatracurium besilate was intravenously injected at a rate of 0.2 mg/kg after loss of consciousness in two groups. The patients were mechanically ventilated after tracheal intubation. Anesthesia was maintained as follows: Remimazolam was intravenously injected at a rate of 0.5-1.0 mg·kg -1·h -1 in group R, propofol was intravenously injected at a rate of 4-10 mg·kg -1·h -1 in group P, and remifentanil was intravenously infused at a rate of 0.25-2.00 μg·kg -1·min -1, maintaining intraoperative bispectral index value of 40-60. The success rate of sedation was recorded, and non-inferiority tests were conducted. The time to loss of consciousness, emergence time, extubation time, recovery time of orientation, time of stay in post-anesthesia care unit and occurrence of delayed emergence were recorded. Liver function and renal function were measured before operation and within 24 h after operation. The occurrence of abnormal alanine transaminase, abnormal aspartate transaminase, abnormal creatinine and abnormal urea was recorded. The occurrence of adverse reactions during and after operation was recorded. Results:The success rates of sedation were 98.6% and 99.3% in group R and group P, respectively, there was no statistically significant difference in the success rate of sedation between the two groups ( P>0.05), and the difference in the success rates of sedation between the two groups was -0.007 (95% confidence interval-0.0301-0.0161), which met the pre-set non-inferiority criteria(95% confidence interval >-0.055). Compared with group P, the time to loss of consciousness and recovery time of orientation were significantly prolonged, and the incidence of delayed emergence was increased ( P<0.05), and no statistically significant changes were found in the emergence time, extubation time, time of stay in post-anesthesia care unit and severity of postoperative nausea and vomiting in group R ( P>0.05). There was no statistically significant difference in the abnormal rates of alanine transaminase, aspartate transaminase, creatinine and urea before and after operation between the two groups ( P>0.05). Conclusions:The efficacy of remimazolam-based anesthesia in daytime laparoscopic cholecystectomy is not inferior to that of propofol-based anesthesia.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

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.

ObjectiveTo investigate the ameliorative effect of Xingpi capsules on functional dyspepsia（FD） and the potential mechanism. MethodsSixty SPF-grade male SD neonatal rats（7 days old） were randomly divided into the normal group（n=12） and the modeling group（n=48）， and the FD model was prepared by iodoacetamide gavage in the modeling group. After the model was successfully prepared， the rats in the modeling group were randomly divided into the model group， the low-dose and high-dose groups of Xingpi capsules（0.135， 0.54 g·kg^-1） and the domperidone group（3 mg·kg^-1）， with 12 rats in each group. Rats in the normal and model groups were gavaged with distilled water， and rats in the rest of the groups were gavaged with the corresponding medicinal solution， once a day for 7 d. The general survival condition of the rats was observed， and the water intake and food intake of the rats were measured， the gastric emptying rate and the small intestinal propulsion rate were measured at the end of the treatment， the pathological damage of the rat duodenum was examined by hematoxylin-eosin（HE） staining， and the expressions of colonic tight junction protein（Occludin） and zonula occludens protein-1（ZO-1） were detected by immunofluorescence. The differentially expressed genes in the duodenal tissues of the model group and the normal group， and the high-dose group of Xingpi capsules and the model group were detected by transcriptome sequencing after the final administration， and Gene Ontology（GO） and Kyoto Encyclopedia of Genes and Genomes（KEGG） enrichment analyses were carried out. The transcriptomic results were validated by Western blot， immunofluorescence， and real-time fluorescence quantitative polymerase chain reaction（Real-time PCR）， and the active ingredients of Xingpi capsules were screened for molecular docking with the key targets. ResultsCompared with the normal group， the general survival condition of rats in the model group was poorer， and the water intake， food intake， gastric emptying rate and small intestinal propulsion rate were all significantly reduced（P<0.05）， inflammatory infiltration was seen in duodenal pathology， and the fluorescence intensities of Occludin and ZO-1 in the colon were significantly reduced（P<0.01）. Compared with the model group， the general survival condition of rats in the high-dose group of Xingpi capsules improved significantly， and the water intake， food intake， gastric emptying rate and small intestinal propulsion rate were all significantly increased（P<0.05）， the duodenal pathology showed a decrease in inflammatory infiltration， and the fluorescence intensities of colonic Occludin and ZO-1 were significantly increased（P<0.01）. Transcriptomic results showed that Xingpi capsules might exert therapeutic effects by regulating the phosphatidylinositol 3-kinase（PI3K）/protein kinase B（Akt） through the key genes such as Slc5a1， Abhd6. The validation results showed that compared with the normal group， the phosphorylation levels of PI3K and Akt proteins， the protein expression level of interleukin（IL）-1β， and the fluorescence intensities of IL-6 and IL-1β were significantly increased in the model group（P<0.05， P<0.01）， and the mRNA levels of Slc5a1， Abhd6， Mgam， Atp1a1， Slc7a8， Cdr2， Chrm3， Slc5a9 and other key genes were significantly increased（P<0.01）. Compared with the model group， the phosphorylation levels of PI3K and Akt， the protein expression level of IL-1β and the fluorescence intensities of IL-6 and IL-1β in the high-dose group of Xingpi capsules were significantly reduced（P<0.05， P<0.01）， and the mRNA levels of Slc5a1， Abhd6， Mgam， Atp1a1， Slc7a8， Cdr2， Chrm3 and Slc5a9 were significantly reduced（P<0.05）. Weighted gene co-expression network analysis and molecular docking results showed that E-nerolidol and Z-nerolidol in Xingpi capsules were well bound to ABDH6 protein， and linarionoside A， valerosidatum and senkirkine were well bound to Slc5a1 protein. ConclusionXingpi capsules can effectively improve the general survival and gastrointestinal motility of FD rats， its specific mechanism may be related to the inhibition of PI3K/Akt signaling pathway to alleviate the low-grade inflammation of duodenum， and E-nerolidol， Z-nerolidol， linarionoside A， valerosidatum and senkirkine may be its key active ingredients.

ObjectiveTo investigate the ameliorative effect of Xingpi capsules on functional dyspepsia（FD） and the potential mechanism. MethodsSixty SPF-grade male SD neonatal rats（7 days old） were randomly divided into the normal group（n=12） and the modeling group（n=48）， and the FD model was prepared by iodoacetamide gavage in the modeling group. After the model was successfully prepared， the rats in the modeling group were randomly divided into the model group， the low-dose and high-dose groups of Xingpi capsules（0.135， 0.54 g·kg^-1） and the domperidone group（3 mg·kg^-1）， with 12 rats in each group. Rats in the normal and model groups were gavaged with distilled water， and rats in the rest of the groups were gavaged with the corresponding medicinal solution， once a day for 7 d. The general survival condition of the rats was observed， and the water intake and food intake of the rats were measured， the gastric emptying rate and the small intestinal propulsion rate were measured at the end of the treatment， the pathological damage of the rat duodenum was examined by hematoxylin-eosin（HE） staining， and the expressions of colonic tight junction protein（Occludin） and zonula occludens protein-1（ZO-1） were detected by immunofluorescence. The differentially expressed genes in the duodenal tissues of the model group and the normal group， and the high-dose group of Xingpi capsules and the model group were detected by transcriptome sequencing after the final administration， and Gene Ontology（GO） and Kyoto Encyclopedia of Genes and Genomes（KEGG） enrichment analyses were carried out. The transcriptomic results were validated by Western blot， immunofluorescence， and real-time fluorescence quantitative polymerase chain reaction（Real-time PCR）， and the active ingredients of Xingpi capsules were screened for molecular docking with the key targets. ResultsCompared with the normal group， the general survival condition of rats in the model group was poorer， and the water intake， food intake， gastric emptying rate and small intestinal propulsion rate were all significantly reduced（P<0.05）， inflammatory infiltration was seen in duodenal pathology， and the fluorescence intensities of Occludin and ZO-1 in the colon were significantly reduced（P<0.01）. Compared with the model group， the general survival condition of rats in the high-dose group of Xingpi capsules improved significantly， and the water intake， food intake， gastric emptying rate and small intestinal propulsion rate were all significantly increased（P<0.05）， the duodenal pathology showed a decrease in inflammatory infiltration， and the fluorescence intensities of colonic Occludin and ZO-1 were significantly increased（P<0.01）. Transcriptomic results showed that Xingpi capsules might exert therapeutic effects by regulating the phosphatidylinositol 3-kinase（PI3K）/protein kinase B（Akt） through the key genes such as Slc5a1， Abhd6. The validation results showed that compared with the normal group， the phosphorylation levels of PI3K and Akt proteins， the protein expression level of interleukin（IL）-1β， and the fluorescence intensities of IL-6 and IL-1β were significantly increased in the model group（P<0.05， P<0.01）， and the mRNA levels of Slc5a1， Abhd6， Mgam， Atp1a1， Slc7a8， Cdr2， Chrm3， Slc5a9 and other key genes were significantly increased（P<0.01）. Compared with the model group， the phosphorylation levels of PI3K and Akt， the protein expression level of IL-1β and the fluorescence intensities of IL-6 and IL-1β in the high-dose group of Xingpi capsules were significantly reduced（P<0.05， P<0.01）， and the mRNA levels of Slc5a1， Abhd6， Mgam， Atp1a1， Slc7a8， Cdr2， Chrm3 and Slc5a9 were significantly reduced（P<0.05）. Weighted gene co-expression network analysis and molecular docking results showed that E-nerolidol and Z-nerolidol in Xingpi capsules were well bound to ABDH6 protein， and linarionoside A， valerosidatum and senkirkine were well bound to Slc5a1 protein. ConclusionXingpi capsules can effectively improve the general survival and gastrointestinal motility of FD rats， its specific mechanism may be related to the inhibition of PI3K/Akt signaling pathway to alleviate the low-grade inflammation of duodenum， and E-nerolidol， Z-nerolidol， linarionoside A， valerosidatum and senkirkine may be its key active ingredients.

Objective To rescue a strain of Chikungunya virus(CHIKV)using reverse genetics system.Methods Molecular cloning experiments,including PCR,agarose gel electrophoresis and homologous recombination were employed to generate an infectious cDNA clone(pFK-CHIKV-LN)derived from the isolated Caribbean Chikungunya strain(Caribbean strain,isolate M100,Genbank LN898083.1).The mRNA obtained from vitro transcription were transfected into BHK-21 to rescue the CHIKV.The viral titer was determined by 50%tissue culture infection dose(TCID50),with calculations performed using the Reed-Muench method.Western blot(WB)and real time quantitative polymerase chain reaction(RT-qPCR)were employed to assess the levels of viral protein and mRNA at various time points during infection.Results The full-length cDNA clone of CHIKV was successfully constructed,enabling the rescue of CHIKV progeny.RT-qPCR and WB confirmed the significant increasing expression levels of NS1 mRNA and proteins(NS3,E1)of BHK-21 during the infection process.Conclusion The full-length infectious clone of CHIKV has been constructed successfully,which provides a good tool for subsequent studies on the gene structure,protein function and pathogenic mechanism of CHIKV.