Objective: To investigate the efficacy of magnesium-strontium co-doped hydroxyapatite mineralized collagen (MSHA/Col) in improving the bone repair microenvironment and enhancing bone regeneration capacity, providing a strategy to address the insufficient biomimetic composition and limited bioactivity of traditional hydroxyapatite mineralized collagen (HA/Col) scaffolds. Methods: A high-molecular-weight polyacrylic acid-stabilized amorphous calcium magnesium strontium phosphate precursor (HPAA/ACMSP) was prepared. Its morphology and elemental distribution were characterized by high-resolution transmission electron microscopy (TEM) and energy-dispersive spectroscopy. Recombinant collagen sponge blocks were immersed in the HPAA/ACMSP mineralization solution. Magnesium-strontium co-doped hydroxyapatite was induced to deposit within collagen fibers (experimental group: MSHA/Col; control group: HA/Col). The morphological characteristics of MSHA/Col were observed using scanning electron microscopy (SEM). Its crystal structure and chemical composition were analyzed by X-ray diffraction and Fourier transform infrared spectroscopy, respectively. The mineral phase content was evaluated by thermogravimetric analysis. The scaffold's porosity, ion release, and in vitro degradation performance were also determined. For cytological experiments, CCK-8 assay, live/dead cell staining, alkaline phosphatase staining, alizarin red S staining, RT-qPCR, and western blotting were used to evaluate the effects of the MSHA/Col scaffold on the proliferation, viability, early osteogenic differentiation activity, late mineralization capacity, and gene and protein expression levels of key osteogenic markers [runt-related transcription factor 2 (Runx2), collagen type Ⅰ (Col-Ⅰ), osteopontin (Opn), and osteocalcin (Ocn)] in mouse embryonic osteoblast precursor cells (MC3T3-E1). Results: HPAA/ACMSP appeared as amorphous spherical nanoparticles under TEM, with energy spectrum analysis showing uniform distribution of carbon, oxygen, calcium, phosphorus, magnesium, and strontium elements. SEM results of MSHA/Col indicated successful complete intrafibrillar mineralization. Elemental analysis showed the mass fractions of magnesium and strontium were 0.72% (matching the magnesium content in natural bone) and 2.89%, respectively. X-ray diffraction revealed characteristic peaks of hydroxyapatite crystals (25.86°, 31°-34°). Infrared spectroscopy results showed characteristic absorption peaks for both collagen and hydroxyapatite. Thermogravimetric analysis indicated a mineral phase content of 78.29% in the material. The scaffold porosity was 91.6% ± 1.1%, close to the level of natural bone tissue. Ion release curves demonstrated sustained release behavior for both magnesium and strontium ions. The in vitro degradation rate matched the ingrowth rate of new bone tissue. Cytological experiments showed that MSHA/Col significantly promoted MC3T3-E1 cell proliferation (130% increase in activity at 72 h, P < 0.001). MSHA/Col exhibited excellent efficacy in promoting osteogenic differentiation, significantly upregulating the expression of osteogenesis-related genes and proteins (Runx2, Col-Ⅰ, Opn, Ocn) (P < 0.01). Conclusion The MSHA/Col scaffold achieves dual biomimicry of natural bone in both composition and structure, and effectively promotes osteogenic differentiation at the genetic and protein levels, breaking through the functional limitations of pure hydroxyapatite mineralized collagen. This provides a new strategy for the development of functional bone repair materials

BACKGROUND:The mechanism of programmed death receptor-1(PD-1)effect on osteogenic differentiation of bone marrow mesenchymal stem cells in high glucose environment remains unclear. OBJECTIVE:To explore the effect of PD-1 on osteogenic differentiation of rat bone marrow mesenchymal stem cells in high glucose environment and its regulatory mechanism. METHODS:Rat bone marrow mesenchymal stem cells were randomly divided into normal glucose group(5.6 mmol/L),high glucose group(30 mmol/L),PD-1 overexpression group,PD-1 overexpression no-load group,PD-1 knockdown group,PD-1 knockdown no-load group,and PI3K/AKT pathway inhibitor group(PD-1 knockdown+5 μmol/L LY294002).Rat bone marrow mesenchymal stem cells were cultured in high glucose to simulate the diabetic environment in vitro.The mRNA expression of PD-1 and ligand PD-L1 and the mRNA expression of osteogenic markers Runx2 and OSX in rat bone marrow mesenchymal stem cells were detected by qRT-PCR.The osteogenic differentiation ability was observed by alkaline phosphatase staining and alizarin red staining.Cell proliferation was detected by CCK-8 assay.The protein expressions of PD-1,PD-L1,p-PI3K,and p-AKT were detected by western blot assay. RESULTS AND CONCLUSION:(1)The levels of PD-1 and PD-L1 were significantly increased in the high glucose environment in vitro,and the osteogenic differentiation ability of bone marrow mesenchymal stem cells was inhibited in the high glucose environment.(2)Knockdown of PD-1 expression could promote osteogenic differentiation of bone marrow mesenchymal stem cells,increase cell proliferation activity,and activate the PI3K/AKT pathway.(3)After addition of PI3K/AKT pathway inhibitor LY294002,the ability of bone marrow mesenchymal stem cells to differentiate into osteoblasts decreased.The results show that PD-1 is dependent on the PI3K/AKT signaling pathway to inhibit osteogenic differentiation of rat bone marrow mesenchymal stem cells under high glucose environment.

Objective To identify the potential pathological mechanisms of tuberculous spondylitis(TS).Methods Spinal specimens were collected from 13 TS patients and 13 controls who received treatment at a hospital from March 2021 to March 2023.Specimens were randomly selected from 3 TS patients and 3 controls to perform high-throughput lncRNAs and mRNAs sequencing with Illumina NovaSeq 6000.Differentially expressed lncRNAs(DELncRs)and mRNAs(DEmRs)in TS specimens were identified and analyzed through differential expression,and enrichment analysis was performed.The top 20 DEmRs with high connectivity were identified through protein-protein interaction(PPI)network.Regulatory network of DElncRs and DEmRs was built.Finally,gene expression of the remaining specimens was analyzed using qRT-PCR detection.Results A total of 1 243 DEmRs and 262 DElncRs were identified.Enrichment analysis revealed that muscle contraction,muscle system processes,muscle structural development,PI3K Akt signaling pathway,calcium signaling pathway,and cAMP signaling pathway were activated in TS,while responses to cytokines,cytokine-mediated signaling pathways,regulation of immune system processes,cytokine-cytokine receptor interactions,human T-cell leukemia virus type 1 infection,and phago-somes were inhibited in TS.Three sub-networks were identified in PPI,among which MYL1,TTN,LOC102723407,HLA-A,interleukin(IL)-6,and IL-1β had the highest connectivity and were identified as key DEmRs.MYL1,TTN,and IL-6 were regulated by DElncRs.qRT-PCR validated the differential expression of key DEmRs in TS.Conclusion DEmRs are regulated by lncRNAs and participate in the pathological process of TS,and the immune responses are inhibited in diseases condition.This study reveals key molecules and signaling pathways in TS,providing new insights into the pathological mechanisms of TS,and suggest scientific basis for developing new therapeutic targets.

OBJECTIVE To analyze the status of targeted monitoring of the health care-associated infections in in-tensive care unit(ICU)of a three-A hospital of northwest China in recent 7 years so as to provide bases for formu-lating effective prevention and control measures for the health care-associated infections.METHODS The related data were successively collected from the ICU hospitalized patients of the Second Affiliated Hospital of Air Force Medical University who were under the targeted monitoring by nosocomial infection real-time monitoring system from Jan.2017 to Dec.2023.The data included the incidence of infections,infection sites,use of catheters,inci-dence of catheter-related infections,and distribution and prevalence trend of pathogens.RESULTS A total of 49,137 hospitalized patients from five ICU wards of respiratory medicine department,neurosurgery department,neurology department,thoracic surgery department and critical care medicine department were under the monito-ring,1446(1681 case-times)of whom had health care-associated infections,with the infection rate 2.94％,the case-time infection rate 3.42％.The respiratory system was the major infection site of the patients with the health care-associated infections.Among the patients with instrument-associated infections,20.70％had ventilator-asso-ciated pneumonia(VAP),5.71％had urinary catheter-associated urinary tract infection(CAUTI),and 1.96％had catheter-related bloodstream infection(CRBSI).Totally 405 strains of non-repetitive pathogens were isolated from 477 patients with instruments-associated infections,78.77％of which were gram-negative bacteria.The iso-lation rate of multidrug-resistant organisms(MDROs)was 44.12％,and Acinetobacter baumannii was the pre-dominant species of pathogen isolated from the patients with VAP.CONCLUSIONS The targeted monitoring of health care-associated infections may facilitate the awareness of dynamic changes of the infections in a accurate and timely manner so as to provide bases for developing effective prevention and control measures for the health care-associated infection.It is necessary to strengthen the prevention and control of the infections in critical care medi-cine department,neurosurgery department as well as the lower respiratory tract infections and prevent the MDROs infection in the meantime.

Objective To identify the potential pathological mechanisms of tuberculous spondylitis(TS).Methods Spinal specimens were collected from 13 TS patients and 13 controls who received treatment at a hospital from March 2021 to March 2023.Specimens were randomly selected from 3 TS patients and 3 controls to perform high-throughput lncRNAs and mRNAs sequencing with Illumina NovaSeq 6000.Differentially expressed lncRNAs(DELncRs)and mRNAs(DEmRs)in TS specimens were identified and analyzed through differential expression,and enrichment analysis was performed.The top 20 DEmRs with high connectivity were identified through protein-protein interaction(PPI)network.Regulatory network of DElncRs and DEmRs was built.Finally,gene expression of the remaining specimens was analyzed using qRT-PCR detection.Results A total of 1 243 DEmRs and 262 DElncRs were identified.Enrichment analysis revealed that muscle contraction,muscle system processes,muscle structural development,PI3K Akt signaling pathway,calcium signaling pathway,and cAMP signaling pathway were activated in TS,while responses to cytokines,cytokine-mediated signaling pathways,regulation of immune system processes,cytokine-cytokine receptor interactions,human T-cell leukemia virus type 1 infection,and phago-somes were inhibited in TS.Three sub-networks were identified in PPI,among which MYL1,TTN,LOC102723407,HLA-A,interleukin(IL)-6,and IL-1β had the highest connectivity and were identified as key DEmRs.MYL1,TTN,and IL-6 were regulated by DElncRs.qRT-PCR validated the differential expression of key DEmRs in TS.Conclusion DEmRs are regulated by lncRNAs and participate in the pathological process of TS,and the immune responses are inhibited in diseases condition.This study reveals key molecules and signaling pathways in TS,providing new insights into the pathological mechanisms of TS,and suggest scientific basis for developing new therapeutic targets.

Objective Five chloroplast(cp)genomes from members of genus Polygonatum were assembled by hybrid assembly technique,and their intraspecic and interspecific differences were analyzed by comparative genomic method.Codon usage patterns and influencing factors were determined,and the cp genome data were applied to understand the phylogenomic relationships in the entire genus Polygonatum along with the available data.Methods In this study,the chloroplast genomes of 5 species of genus Polygonatum were assembled using Unicycler software.Sequence alignment,collinearity analysis,boundary analysis and other methods were used to evaluate the interspecific differences of these five species.Nucleotide polymorphism analysis was used to discover the high-variation sites of the five species and their related species,predict the distribution of different long repeat sequences and SSRs,and then analyze the use bias of Polygonatum code.Finally,phylogenetic tree was constructed with the coding sequences of other 47 genus Polygonatum and their closely related species to explore their phylogenetic relationships in this study.Results ①Chloroplast genomes of 155 408-155 623 bp were assembled from five species of Polygonatum.A total of 132-133 genes were annotated,and 369 long repeats and 1553 simple repeats were detected.②The contraction and expansion of chloroplast genomes in 8 species were not obvious at the IRs boundary,and the size and distribution of individual genes at the LSC-IRs-SSC boundary,such as ndhF gene and ycf1 gene,were slightly different.No interspecific or intraspecific rearrangement was observed in 8 species.③ The high-variation regions of the 8 chloroplast genomes are mainly located in two single-copy regions,the duplicate copy region is relatively conserved,and the coding region is more conserved than the non-coding region.High nucleotide polymorphic loci rps16-trnQ,trnS-trnG,trnTUGU-trnL,ndhF-rpl32 and rpl32-trnL are located in the single copy region and most of them are gene spacer regions.④ The codon preference results showed that the codon preference of the five species was similar and mainly affected by selection pressure,and the third base of the codon played A dominant role and mainly ended in A/U.RSCU clustering heat map shows that PK and PZ,PCB and PS have close relationship.⑤ Phylogenetic trees divided 52 species into five branches:Ⅰ,Ⅱ,Ⅲ,ⅣandⅤ.PS,PK,PCB,PCZ and PZ were divided into ⅣandⅤbranches,among which PK and PZ were most closely related,while PCZ was more distant than the other four,was divided into the Ⅴbranch alone.Conclusion This study provided a reference for the phylogenetic research and molecular marker development of the medicinal plants of the Polygonum genus.

Aimed to find a safe and effective drug to replace nitroimidazole drugs in aquaculture pro-duction for the prevention and treatment of Trichomoniasis in pigeons,which can improve the eco-nomic benefits of meat pigeon breeding and ensure food safety.Firstly,Trichomonas was isolated and cultured from the crop of diseased pigeons and identified.After stable passage,a quantitative method for in vitro detection of Trichomonas was established by combining an automated cell counter and quantitative real-time PCR technology.To prepared the drug,powders of Sophora fla-vescent and Philodendron were made into herbal water extracts(SFPA)and mixed with copper sulfate(CS)solution.Then added the drug to the culture medium of Trichomonas to determine the effective concentration of it.A total of 135 pairs each of Silver King and Mimas breeding pigeons in the same laying period were selected and randomly divided into three groups,with 6 replicates in each group and 15 pairs of breeding pigeons in each replicate.Four days before brooding,the three groups were fed with 200 mL of pure water,0.5 g/L metronidazole(MDZ)solution,and a mixed solution of 30 g/L SFPA and 0.5 g/L CS,respectively.The feeding experiment lasted for 26 d.Results showed that the mixed solution of SFPA and CS had a significant killing effect on Trichomonas in vitro(P＜0.05).Feeding the drug to breeding pigeons significantly reduced the in-fection rate of breeding pigeons by Trichomonas(P＜0.05).The drug had no significant effect on the serum biochemical indexes,antioxidant properties,immunoglobulin levels of breeding pigeons,the average cage weight,immune organ indexes,meat quality and slaughter performance of squabs(P＞0.05).The results suggested that adding SFPA and CS to pigeons can effectively prevent and treat Trichomoniasis and improve production performance.It can replace nitroimidazole drugs without affecting the immune level of breeding pigeons and the weight,immune level,slaughter performance and meat quality of squabs,thereby reduce drug residues in poultry products and en-hance the food safety.

Objective:To simulate and compare the impact of scar contraction force on maxillary alveolar bone displacement after cleft palate surgery in different regions of the palate.Methods:The same scar contraction force was applied to the grouping hard pal-ate area on the original finite element model of the maxilla with cleft palate,and calculations were performed in ANSYS 17.0.Divid-ed into four groups based on the applied force area:anterior half(group 1),posterior half(group 2),lateral half(group 3),and me-dial half(group 4).Nodes in the alveolar bone of the cleft and non-cleft sides were selected as observation points.The three-dimen-sional displacement of observation points was recorded and compared between groups.Results:The displacement of group 1＞group 3,4＞group 2(P＜0.01).Conclusion:Scars from different parts of the hard palate can lead to a decrease in the length,width,and height of the maxillary alveolar bone.Among them,the anterior scar has the most severe impact,followed by the medial and lateral scars,and the posterior scar has the smallest impact.

Objective:To simulate and compare the impact of scar contraction force on maxillary alveolar bone displacement after cleft palate surgery in different regions of the palate.Methods:The same scar contraction force was applied to the grouping hard pal-ate area on the original finite element model of the maxilla with cleft palate,and calculations were performed in ANSYS 17.0.Divid-ed into four groups based on the applied force area:anterior half(group 1),posterior half(group 2),lateral half(group 3),and me-dial half(group 4).Nodes in the alveolar bone of the cleft and non-cleft sides were selected as observation points.The three-dimen-sional displacement of observation points was recorded and compared between groups.Results:The displacement of group 1＞group 3,4＞group 2(P＜0.01).Conclusion:Scars from different parts of the hard palate can lead to a decrease in the length,width,and height of the maxillary alveolar bone.Among them,the anterior scar has the most severe impact,followed by the medial and lateral scars,and the posterior scar has the smallest impact.

Aimed to find a safe and effective drug to replace nitroimidazole drugs in aquaculture pro-duction for the prevention and treatment of Trichomoniasis in pigeons,which can improve the eco-nomic benefits of meat pigeon breeding and ensure food safety.Firstly,Trichomonas was isolated and cultured from the crop of diseased pigeons and identified.After stable passage,a quantitative method for in vitro detection of Trichomonas was established by combining an automated cell counter and quantitative real-time PCR technology.To prepared the drug,powders of Sophora fla-vescent and Philodendron were made into herbal water extracts(SFPA)and mixed with copper sulfate(CS)solution.Then added the drug to the culture medium of Trichomonas to determine the effective concentration of it.A total of 135 pairs each of Silver King and Mimas breeding pigeons in the same laying period were selected and randomly divided into three groups,with 6 replicates in each group and 15 pairs of breeding pigeons in each replicate.Four days before brooding,the three groups were fed with 200 mL of pure water,0.5 g/L metronidazole(MDZ)solution,and a mixed solution of 30 g/L SFPA and 0.5 g/L CS,respectively.The feeding experiment lasted for 26 d.Results showed that the mixed solution of SFPA and CS had a significant killing effect on Trichomonas in vitro(P＜0.05).Feeding the drug to breeding pigeons significantly reduced the in-fection rate of breeding pigeons by Trichomonas(P＜0.05).The drug had no significant effect on the serum biochemical indexes,antioxidant properties,immunoglobulin levels of breeding pigeons,the average cage weight,immune organ indexes,meat quality and slaughter performance of squabs(P＞0.05).The results suggested that adding SFPA and CS to pigeons can effectively prevent and treat Trichomoniasis and improve production performance.It can replace nitroimidazole drugs without affecting the immune level of breeding pigeons and the weight,immune level,slaughter performance and meat quality of squabs,thereby reduce drug residues in poultry products and en-hance the food safety.