BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

This study aimed to investigate the effects of zidovudine (AZT) on high-fat diet (HFD)-induced metabolic disturbances in rats and its underlying mechanisms. The HFD rat model was established, and the animals were divided into the control group, the model group, and the AZT-treated group at low (25 mg/kg) and high (50 mg/kg) doses. Metabolic phenotype, hepatic lipid deposition, oxidative stress, mitochondrial function, and peroxisome proliferator-activated receptor (PPAR) signaling were evaluated. AZT treatment significantly mitigated HFD-induced body weight gain and reduced both the mass and adipocyte size of inguinal and epididymal white adipose tissues; it also enhanced metabolic flexibility and improved glucose tolerance without elevating blood lactate levels. High-dose AZT further lowered hepatic triglyceride accumulation, ameliorated steatosis, and additionally, attenuated hepatic oxidative stress by increasing superoxide dismutase (SOD) activity and decreasing malondialdehyde (MDA) levels. Western blot analysis revealed that AZT upregulated hepatic PPARα and carnitine palmitoyltransferase 1α (CPT1α), while downregulating PPARγ expression. In conclusion, AZT effectively ameliorates HFD-induced metabolic disorders without inducing mitochondrial toxicity, which may be related to the promotion of fatty acid oxidation, the reduction of oxidative stress, and the modulation of both the PPAR signaling pathway and pyrimidine metabolism.

BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

Objective: To investigate the stability of plasma from blood donors cryopreserved at-80℃for two months in ELISA and NAT detection (HBV, HCV, and HIV), and to provide a reference for the preservation, transportation, and retrospective testing of samples collected in remote areas or during emergency blood collection. Methods: Three sets of experimental designs were adopted, each including ELISA (HBsAg, anti-HCV, HIV Ag-Ab) and NAT (HBV DNA, HCV RNA, HIV-1 RNA) testing. Stability validation test: 136 positive and 150 negative donor samples were selected, retested with the original reagents after cryopreservation at-80℃for two months, and the ELISA S/CO values, NAT Ct values, and result concordance rates before and after freezing were compared. Limit of detection validation test: Standard substances with known concentrations were diluted into three gradients of weakly reactive samples (ELISA S/CO values of 0.8-5, NAT Ct values of 35-42). Each was tested six times before and after freezing, the mean values were calculated, and the ELISA S/CO values and NAT Ct values were compared. Real-world validation test: 300 randomly selected donor samples were subjected to plasma separation after initial testing and cryopreserved for two months. The reactive detection rates of ELISA and NAT before and after freezing were compared. Results: Stability validation test: In ELISA testing, 3 samples converted from weak-positive to negative, and 3 samples converted from weak-positive to gray zone, yielding a concordance rate of 97.9%. In NAT testing, 2 samples converted from weak-positive to gray zone, yielding a concordance rate of 99.30%. Significant differences were observed in both ELISA S/CO values and NAT Ct values after freezing (P<0.05). Limit of detection validation test: No significant differences were found in ELISA S/CO values or NAT Ct values for the three concentrations of weakly reactive samples before and after freezing (P>0.05); only the anti-HCV ELISA result for the 0.5 NCU/mL sample converted from positive to the gray zone. Real-world validation test: The ELISA reactive detection rates before and after freezing were 1.67% vs 1.00%, and the NAT reactive detection rates were 0.33% vs 0.33%, with no significant differences (P≥0.05). Conclusion: After cryopreservation of donor plasma at-80℃for two months, the overall concordance rates for ELISA and NAT testing are extremely high. Although weak-positive samples are susceptible to freezing effects, the overall qualitative results remain stable, demonstrating that deep-low temperature cryopreservation can effectively maintain the stability of viral marker detection.

Objective:To construct analytical dimensions for policy texts related to the pilot work of Health Impact Assessment (HIA) system in Zhejiang Province and conduct quantitative analysis, thereby providing references for improving the pilot work.Methods:Policy texts issued by Zhejiang Province between February 11, 2018, and February 29, 2024, which involved HIA content, were selected. The policy instruments theory was employed to construct an analytical framework around the dimensions of policy instruments, policy objectives, policy actors, and the interactions between policy instruments and policy objectives, and between policy instruments and policy actors. Based on this framework, a combination of literature analysis and content analysis was used to conduct a multi-dimensional quantitative analysis of the policy texts related to the pilot work of HIA system in Zhejiang Province.Results:Fifty core policy texts were included and 1 588 codes were obtained. In terms of policy instruments, environmental-type instruments were the most widely used (852 items), with internal responsibilities and methodological measures being the most frequently used; supply-type instruments were the second most used (459 items), with mechanism improvement being the most frequently used; demand-type instruments were the least used (277 items), with multi-stakeholder participation being the most frequently used. In terms of policy objectives, the objective of system construction dominated (701 articles, accounting for 56.45%), while the proportion of policy coverage, evaluation technology, and effectiveness evaluation was relatively low. In terms of policy subjects, the Party committee and government were the main policy subjects (434 articles, accounting for 39.20%), followed by health departments and public policy-making departments, while the proportion of public health institutions and social forces was extremely low. In the interaction between policy instruments and policy objectives, policy coverage, system construction, and effectiveness evaluation objectives all responded most frequently to environmental-type instruments, while the evaluation technology objectives responded more frequently to supply-type instruments. In the interaction between policy instruments and policy subjects, the Party committee and government played a dominant role in the use of policy instruments, with the health department and public policy-making department in the middle.Conclusions:The pilot work of the HIA system in Zhejiang Province presented a " environment-driven, system-construction-priority, Party-committee-and-government-led" policy characteristic. The main challenges were the imbalanced structure of policy instruments, insufficient synergy among policy objectives, and the need for greater participation of multiple stakeholders.

Objective·To investigate the changes in transcriptome and chromatin accessibility during the differentiation of human embryonic stem cells(hESCs)into neural progenitor cells(NPCs)using in vitro differentiation models and high-throughput multi-omics sequencing technologies.Methods·hESCs were first induced to differentiate into NPCs in vitro using the embryoid body formation method,and cells at both stages were collected.The cell phenotypes were identified by reverse transcription-quantitative real-time PCR(RT-qPCR)and immunofluorescence(IF)staining.Transcriptome sequencing(RNA-seq)was conducted to detect and analyze the differentially expressed genes(DEGs)between hESCs and NPCs.The assay for transposase-accessible chromatin with high-throughput sequencing(ATAC-seq)was employed to assess chromatin accessibility changes between hESCs and NPCs.Motif enrichment analysis was performed on differentially accessible chromatin regions to discover potential regulatory transcription factors.Finally,an integrated analysis of RNA-seq and ATAC-seq data and the protein-protein interaction(PPI)network were performed to identify key genes and regulatory pathways involved in the early stages of neural differentiation in vitro.Results·Both RT-qPCR and IF results indicated that the expression levels of pluripotency markers(NANOG and POU5F1)were high at the hESC stage but significantly decreased at the NPC stage,while early neural differentiation markers(PAX6,SOX1,and NES)were minimally expressed at the hESC stage but markedly upregulated at the NPC stage.RNA-seq analysis revealed that compared to the hESC stage,there were 5 597 genes upregulated and 3 654 genes downregulated at the NPC stage.Gene function enrichment analysis showed that the upregulated genes at the NPC stage were enriched in the functions related to neural development.ATAC-seq analysis demonstrated a total of 27 491 genomic regions had significant changes in chromatin accessibility during the differentiation from hESC to NPC,with 12 381 regions showing increased accessibility and 15 110 regions showing decreased accessibility.Motif enrichment analysis revealed that transcription factor genes such as DLX1 and LHX2 might play an important role in the differentiation process from hESCs into NPCs.Integrated analysis of RNA-seq and ATAC-seq data revealed that overlapping genes with high expression at the NPC stage were mainly enriched in axon guidance,forebrain development,and neuron migration.After neural differentiation,the expression levels of CTNND2 and LHX2 genes increased,and the chromatin accessibility of related genomic regions also increased.PPI network analysis indentified candidate downstream genes including PRKACA,CDH2,and ERBB4.Conclusion·The in vitro differentiation model of hESCs combined with high-throughput multi-omics sequencing technologies can be used to depict the changes in transcriptome and chromatin accessibility during the differentiation of hESCs into NPCs.In this process,the expression levels of genes related to axon guidance,forebrain development,and neuronal migration pathways increase and related chromatin accessibility is enhanced.

Objective:To investigate the relationship between different types of tea intake and COVID-19 infection.Methods:Data were retrieved from a genome-wide association study(GWAS),involving 447 485,and 64 949 people for single nucleotide polymorphisms(SNPs).Two-sample Mendelian randomization(MR)analysis was used to investigate the relationship of different types of tea intake with four subgroups of COVID-19 infected population,including COVID-19 infected population versus general population,COVID-19 hospitalized population versus general population,COVID-19 hospitalized population versus non-hospitalized population,and very severe respiratory confirmed population versus general population.Inverse-variance weighted(IVW)method was used as the main method of causal analysis.MR Egger intercept was used for pleiotropy test,and Cochran's Q-statistic was used for heterogeneity test.Results:Compared to the general population,tea intake decreased the incidence of COVID-19 in the infection population(IVW method,OR=0.806,95%CI:0.651-0.999),and the hospitalized population(IVW method,OR=0.533,95%CI:0.369-0.770).Additionally,the underlying pleiotropy was not found following the MR-Egger regression intercept(MR intercept=-0.002,P=0.667),and the Cochran's Q-statistic showed no heterogeneity(Q-statistic=52.712,P=0.057).Compared to the general population,the underlying pleiotropy in the hospitalized patients was not found by MR-Egger regression intercept(MR intercept=-0.001,P=0.909),and the Cochran's Q-statistic showed no heterogeneity(Q-statistic=25.214,P=0.945).However,green tea and herbal tea had no effect on COVID-19 infection.Conclusions:Overall tea intake reduces the risk of COVID-19 infection in the general population compared to COVID-19 infected and hospitalized populations,while green tea and herbal tea have no protective effect against COVID-19 infection.

Objective:To analyze the changes in the prevalence characteristics of multimorbidity among adolescents aged 13-18 in Inner Mongolia Autonomous Region from 2019 to 2022 and to explore the association between multimorbidity and moderate to high-intensity physical activity among them.Methods:A stratified random cluster sampling method was used to select students aged 13-18 in Inner Mongolia Autonomous Region every September from 2019 to 2022. Physical examinations, demographic characteristics, and depression-related surveys were conducted to analyze the multimorbidity of overweight, obesity, high blood pressure, myopia, spinal curvature abnormality, and depression. A logistic regression model was used to analyze the association between multimorbidity and moderate to high-intensity physical activity.Results:From 2019 to 2022, 70 972, 62 923, 80 254, and 78 288 study subjects were included, with the rates of multimorbidity being 56.4%, 55.4%, 57.2%, and 55.8%, respectively. The rates of multimorbidity remained relatively stable from 2019 to 2022 ( χ2=0.06, P=0.950). The incidence of multimorbidity among girls was significantly higher than that among boys ( P<0.001). The incidence of multimorbidity among urban students was significantly higher than that among suburban students ( P<0.001). The incidence of multimorbidity among high school students was higher than that among middle school students ( P<0.001). The top three multimorbidity combinations were myopia and overweight/obesity (26.4%), myopia and high blood pressure (24.4%), and myopia and depression (19.8%), while the least common combination was depression and spinal curvature abnormality (1.1%). The multimorbidity patterns showed no significant differences between years ( χ2=0.03, P=0.999). The multimorbidity status was significantly associated with the status of meeting the standard of moderate to high-intensity physical activity ( OR=0.83, 95% CI: 0.80-0.86). The association was stronger in boys ( OR=0.77, 95% CI: 0.73-0.81) compared with girls ( OR=0.90, 95% CI: 0.85-0.96), with a significant interaction term ( P<0.001). Conclusion:From 2019 to 2022, the incidence of multimorbidity among adolescents aged 13 to 18 in Inner Mongolia Autonomous Region is relatively high, mainly due to the co-occurrence of myopia and other health problems. Adequate physical activity is an important factor in reducing multimorbidity.

Objective·To investigate the changes in transcriptome and chromatin accessibility during the differentiation of human embryonic stem cells(hESCs)into neural progenitor cells(NPCs)using in vitro differentiation models and high-throughput multi-omics sequencing technologies.Methods·hESCs were first induced to differentiate into NPCs in vitro using the embryoid body formation method,and cells at both stages were collected.The cell phenotypes were identified by reverse transcription-quantitative real-time PCR(RT-qPCR)and immunofluorescence(IF)staining.Transcriptome sequencing(RNA-seq)was conducted to detect and analyze the differentially expressed genes(DEGs)between hESCs and NPCs.The assay for transposase-accessible chromatin with high-throughput sequencing(ATAC-seq)was employed to assess chromatin accessibility changes between hESCs and NPCs.Motif enrichment analysis was performed on differentially accessible chromatin regions to discover potential regulatory transcription factors.Finally,an integrated analysis of RNA-seq and ATAC-seq data and the protein-protein interaction(PPI)network were performed to identify key genes and regulatory pathways involved in the early stages of neural differentiation in vitro.Results·Both RT-qPCR and IF results indicated that the expression levels of pluripotency markers(NANOG and POU5F1)were high at the hESC stage but significantly decreased at the NPC stage,while early neural differentiation markers(PAX6,SOX1,and NES)were minimally expressed at the hESC stage but markedly upregulated at the NPC stage.RNA-seq analysis revealed that compared to the hESC stage,there were 5 597 genes upregulated and 3 654 genes downregulated at the NPC stage.Gene function enrichment analysis showed that the upregulated genes at the NPC stage were enriched in the functions related to neural development.ATAC-seq analysis demonstrated a total of 27 491 genomic regions had significant changes in chromatin accessibility during the differentiation from hESC to NPC,with 12 381 regions showing increased accessibility and 15 110 regions showing decreased accessibility.Motif enrichment analysis revealed that transcription factor genes such as DLX1 and LHX2 might play an important role in the differentiation process from hESCs into NPCs.Integrated analysis of RNA-seq and ATAC-seq data revealed that overlapping genes with high expression at the NPC stage were mainly enriched in axon guidance,forebrain development,and neuron migration.After neural differentiation,the expression levels of CTNND2 and LHX2 genes increased,and the chromatin accessibility of related genomic regions also increased.PPI network analysis indentified candidate downstream genes including PRKACA,CDH2,and ERBB4.Conclusion·The in vitro differentiation model of hESCs combined with high-throughput multi-omics sequencing technologies can be used to depict the changes in transcriptome and chromatin accessibility during the differentiation of hESCs into NPCs.In this process,the expression levels of genes related to axon guidance,forebrain development,and neuronal migration pathways increase and related chromatin accessibility is enhanced.

Objective:To investigate the relationship between different types of tea intake and COVID-19 infection.Methods:Data were retrieved from a genome-wide association study(GWAS),involving 447 485,and 64 949 people for single nucleotide polymorphisms(SNPs).Two-sample Mendelian randomization(MR)analysis was used to investigate the relationship of different types of tea intake with four subgroups of COVID-19 infected population,including COVID-19 infected population versus general population,COVID-19 hospitalized population versus general population,COVID-19 hospitalized population versus non-hospitalized population,and very severe respiratory confirmed population versus general population.Inverse-variance weighted(IVW)method was used as the main method of causal analysis.MR Egger intercept was used for pleiotropy test,and Cochran's Q-statistic was used for heterogeneity test.Results:Compared to the general population,tea intake decreased the incidence of COVID-19 in the infection population(IVW method,OR=0.806,95%CI:0.651-0.999),and the hospitalized population(IVW method,OR=0.533,95%CI:0.369-0.770).Additionally,the underlying pleiotropy was not found following the MR-Egger regression intercept(MR intercept=-0.002,P=0.667),and the Cochran's Q-statistic showed no heterogeneity(Q-statistic=52.712,P=0.057).Compared to the general population,the underlying pleiotropy in the hospitalized patients was not found by MR-Egger regression intercept(MR intercept=-0.001,P=0.909),and the Cochran's Q-statistic showed no heterogeneity(Q-statistic=25.214,P=0.945).However,green tea and herbal tea had no effect on COVID-19 infection.Conclusions:Overall tea intake reduces the risk of COVID-19 infection in the general population compared to COVID-19 infected and hospitalized populations,while green tea and herbal tea have no protective effect against COVID-19 infection.