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.

ObjectiveMitochondria are not only the central organelles responsible for cellular energy metabolism but also play essential roles in regulating cell cycle progression and cytoskeletal dynamics. In recent years, accumulating evidence has demonstrated that mitochondrial homeostasis is closely associated with mitotic progression and cytokinesis. Schizosaccharomyces pombe serves as a classical and well-established model organism. Because its cell cycle regulatory mechanisms are highly conserved throughout evolution, its genetic background is clearly defined, and experimental manipulation is efficient and convenient, it has been extensively applied in studies of cell growth, division, and reproductive mechanisms. The SPBC1604.04 gene encodes a previously uncharacterized mitochondrial carrier protein in Schizosaccharomyces pombe. This gene is located on chromosome II and spans 1 018 base pairs in length. It encodes a protein consisting of 238 amino acids with a predicted molecular mass of approximately 31.03 ku. Bioinformatic analysis predicts that this protein is responsible for the transport of thiamine pyrophosphate (TPP) into mitochondria. However, the effects of SPBC1604.04 gene deletion on mitotic cell dynamics under different temperature conditions have not been fully elucidated. MethodsThe SPBC1604.04 deletion strain of Schizosaccharomyces pombe was used as the experimental model. Fluorescent protein markers were constructed in the deletion background to label mitochondria, microtubules, actin, myosin, the nuclear envelope, and chromosomes. Live-cell imaging was performed using a TCS-SP8 laser scanning confocal microscope under normal temperature conditions (25℃) and heat stress conditions (37℃). Time-lapse microscopy was applied to dynamically monitor mitochondrial morphology and distribution, spindle assembly and elongation, chromosome segregation, as well as the formation and constriction of the actomyosin ring during cytokinesis. ImageJ software was used for quantitative measurements, including microtubule length during mitosis, spindle length at different mitotic stages, mitochondrial fluorescence intensity as an indicator of mitochondrial content, actomyosin ring length, nuclear envelope area, and chromosome segregation timing. Statistical analyses were conducted to compare phenotypic differences between the wild-type and SPBC1604.04 deletion strains at both temperature conditions. Through these analyses, we systematically investigated the impact of SPBC1604.04 deletion on mitotic cell dynamics in fission yeast under both normal physiological conditions and temperature stress. ResultsAt 25℃, compared with wild-type cells, the SPBC1604.04Δ strain exhibited a pronounced tendency toward mitochondrial fragmentation, accompanied by abnormal mitochondrial content and a significant reduction in mitochondrial fluorescence intensity. These observations suggest impaired mitochondrial homeostasis under normal growth conditions. In addition, the constriction time of actomyosin ring during cytokinesis was markedly prolonged, indicating that deletion of SPBC1604.04 affects the dynamics of the contractile machinery. However, no obvious defects were observed in spindle assembly, spindle elongation, or chromosome segregation. Under heat stress at 37℃, mitochondrial morphology in the SPBC1604.04Δ strain showed a tendency to recover toward a continuous tubular network structure. Mitochondrial content was restored, fluorescence intensity increased, and the constriction time of the actomyosin ring returned to levels comparable to those of wild-type cells. These results indicate that the mitotic defects observed at normal temperature are partially or fully alleviated under heat stress conditions. ConclusionThis study demonstrates that deletion of the SPBC1604.04 gene leads to abnormal mitochondrial content in Schizosaccharomyces pombe. The mitochondrial carrier protein SPBC1604.04 participates in regulating actomyosin ring constriction during mitosis but does not appear to be directly involved in the regulation of spindle dynamics or chromosome segregation. Our findings provide key experimental evidence for understanding the functional link between the SPBC1604.04 gene, mitochondrial homeostasis, and mitotic regulation.

ObjectiveMitochondria are not only the central organelles responsible for cellular energy metabolism but also play essential roles in regulating cell cycle progression and cytoskeletal dynamics. In recent years, accumulating evidence has demonstrated that mitochondrial homeostasis is closely associated with mitotic progression and cytokinesis. Schizosaccharomyces pombe serves as a classical and well-established model organism. Because its cell cycle regulatory mechanisms are highly conserved throughout evolution, its genetic background is clearly defined, and experimental manipulation is efficient and convenient, it has been extensively applied in studies of cell growth, division, and reproductive mechanisms. The SPBC1604.04 gene encodes a previously uncharacterized mitochondrial carrier protein in Schizosaccharomyces pombe. This gene is located on chromosome II and spans 1 018 base pairs in length. It encodes a protein consisting of 238 amino acids with a predicted molecular mass of approximately 31.03 ku. Bioinformatic analysis predicts that this protein is responsible for the transport of thiamine pyrophosphate (TPP) into mitochondria. However, the effects of SPBC1604.04 gene deletion on mitotic cell dynamics under different temperature conditions have not been fully elucidated. MethodsThe SPBC1604.04 deletion strain of Schizosaccharomyces pombe was used as the experimental model. Fluorescent protein markers were constructed in the deletion background to label mitochondria, microtubules, actin, myosin, the nuclear envelope, and chromosomes. Live-cell imaging was performed using a TCS-SP8 laser scanning confocal microscope under normal temperature conditions (25℃) and heat stress conditions (37℃). Time-lapse microscopy was applied to dynamically monitor mitochondrial morphology and distribution, spindle assembly and elongation, chromosome segregation, as well as the formation and constriction of the actomyosin ring during cytokinesis. ImageJ software was used for quantitative measurements, including microtubule length during mitosis, spindle length at different mitotic stages, mitochondrial fluorescence intensity as an indicator of mitochondrial content, actomyosin ring length, nuclear envelope area, and chromosome segregation timing. Statistical analyses were conducted to compare phenotypic differences between the wild-type and SPBC1604.04 deletion strains at both temperature conditions. Through these analyses, we systematically investigated the impact of SPBC1604.04 deletion on mitotic cell dynamics in fission yeast under both normal physiological conditions and temperature stress. ResultsAt 25℃, compared with wild-type cells, the SPBC1604.04Δ strain exhibited a pronounced tendency toward mitochondrial fragmentation, accompanied by abnormal mitochondrial content and a significant reduction in mitochondrial fluorescence intensity. These observations suggest impaired mitochondrial homeostasis under normal growth conditions. In addition, the constriction time of actomyosin ring during cytokinesis was markedly prolonged, indicating that deletion of SPBC1604.04 affects the dynamics of the contractile machinery. However, no obvious defects were observed in spindle assembly, spindle elongation, or chromosome segregation. Under heat stress at 37℃, mitochondrial morphology in the SPBC1604.04Δ strain showed a tendency to recover toward a continuous tubular network structure. Mitochondrial content was restored, fluorescence intensity increased, and the constriction time of the actomyosin ring returned to levels comparable to those of wild-type cells. These results indicate that the mitotic defects observed at normal temperature are partially or fully alleviated under heat stress conditions. ConclusionThis study demonstrates that deletion of the SPBC1604.04 gene leads to abnormal mitochondrial content in Schizosaccharomyces pombe. The mitochondrial carrier protein SPBC1604.04 participates in regulating actomyosin ring constriction during mitosis but does not appear to be directly involved in the regulation of spindle dynamics or chromosome segregation. Our findings provide key experimental evidence for understanding the functional link between the SPBC1604.04 gene, mitochondrial homeostasis, and mitotic regulation.

We report a case of a female farmer from the Yichang suburb, aged 68 years, who had been suffering from the infection for 3 years and had a history of seeking medical treatment at a community hospital and receiving blood transfusions. Her hemoglobin was as low as 28 g/L during this visit, and she had been ill for a long time with severe anemia. Routine stool examination revealed hookworm eggs. After active treatment, the patient recovered and was discharged from the hospital.

Tuberculosis （TB） is a major infectious disease that seriously endangers public health. In traditional Chinese medicine （TCM）， TB is considered to be caused by "exogenous latent tuberculosis pathogens"， and whether the disease occurs depends on the strength of healthy Qi. The disease course is characterized by five features： Hidden latency， pathological accumulation， triggering due to deficiency of healthy Qi， depletion of healthy Qi， and prolonged progression with difficulty in recovery. The latent stage is based on the fundamental pathogenesis of "specific latent pathogens concealed in the lung collaterals and waiting for the appropriate time to manifest"， which exhibits the temporal and spatial characteristics of latent pathogens. During this stage， Mycobacterium tuberculosis remains in a dormant state and maintains a dynamic balance with the host immune system. The triggering and progression stages are characterized by the core pathogenesis of "deficiency of healthy Qi initiating pathogenic factors and excessive pathogenic factors triggering disease". Immune dysfunction may lead to severe pathological damage to the structure of the lung collaterals. The key pathogenesis of the latent-retention stage is "persistent latent pathogens consuming healthy Qi"， which is also the core reason for the difficulty in treating initial TB onset， prolonged disease progression， and recurrent attacks. Based on the theory of latent pathogens， this study establishes a four-stage prevention and treatment system "with pathogenesis as the guiding principle and disease stages as the criteria". The corresponding therapeutic principles include tonifying Qi and nourishing Yin， clearing and transforming latent phlegm， regulating and tonifying the spleen and kidney， strengthening healthy Qi and replenishing the primordial Qi， nourishing Yin and reducing fire， suppressing and eliminating tuberculosis pathogens， tonifying deficiency， restoring primordial Qi， clearing residual pathogens， and eliminating pathogenic factors. Guided by the theory of latent pathogens， this article systematically elucidates the TCM connotation of M. tuberculosis invasion of the lung collaterals and the staged syndrome differentiation and treatment approach， providing theoretical foundations and practical guidance for the prevention and treatment of TB through integrated Chinese and Western medicine and offering new perspectives for the prevention and control of infectious diseases using TCM.

Abstract To improve the mental health status of college students, the study systematically sorts out the current applications of artificial intelligence (AI) technology in psychological assessment, early warning and intervention for college students, and identifies existing challenges including technical limitations, ethical issues and privacy leakage risks. It proposes countermeasures such as strengthening technological innovation and perfecting relevant laws and regulations to address the challenges brought by AI applications, so as to promote the sustainable development of mental health services for college students.

BackgroundMetabolic syndrome （MetS） is highly prevalent in patients with mental disorders， including elevated diastolic or systolic blood pressure， elevated fasting glucose， hypercholesterolemia， abdominal obesity and so on. As an important component of MetS， the relationship between hypercholesterolemia and mental disorder has been extensively reported， whereas few genome-wide association studies （GWAS） have been conducted to identify the causal role of mental disorders in hypercholesterolemia. ObjectiveTo explore the potential causal relationship between mental disorders and hypercholesterolemia by two-sample Mendelian randomization （MR） method. MethodsSummary data from GWAS were analyzed. Single nucleotide polymorphisms （SNPs） strongly associated with mental disorders were chosen as instrumental variables， and hypercholesterolemia was used as outcome variable. MR analysis utilized inverse-variance weighted （IVW）， MR-Egger regression and weighted median estimation （WME） as the primary analytical tool， and supplemented by simple mode （SM） and weighted mode （WM）. The causal relationship between mental disorders and the risk of hypercholesterolemia was illustrated in terms of odds ratio （OR）. ResultsA total of 36 SNPs associated with mental disorders were identified as instrumental variables. The primary findings from IVW revealed existence of a causal relationship between mental disorders and hypercholesterolemia （IVW： OR=1.067， 95% CI： 1.026~1.109， P=0.001）. Findings from the additional methods （MR-Egger regression， WME， SM， WM） were basically consistent with those reported in IVW method. Further verification indicated that the causal relationship between mental disorders and the risk of hypercholesterolemia was not affected by genetic polymorphism （P>0.05）. The absence of heterogeneity was confirmed through Cochran's Q test and MR-Egger regression （P>0.05）. Furthermore， no causal association in the reverse direction was found （P>0.05）. ConclusionThere is a causal relationship between mental disorders and hypercholesterolemia， and patients with mental disorders may have an increased probability of suffering from hypercholesterolemia.

The Chinese Pharmacopoeia is the legal technical standard which should be followed during the research, production, use, and administration of drugs. At present, the new edition of the Chinese Pharmacopoeia is planned to be promulgated and implemented. This article summarizes and analyzes the main characteristics and the content of updates and amendments of the Chinese Pharmacopoeia 2025 Edition(Volume Ⅰ), to provide a reference for the correct understanding and accurate implementation the new edition of the pharmacopoeia.

Objective To develop an ultra-sensitive nanoparticle contrast agent for magnetic resonance angiography(MRA),to establish a highly sensitive imaging method for complicated vascular structures,and to provide imaging evidence for precision diagnosis,treatment,prognosis,and individualized treatment of ischemic stroke.Methods A dual-modality MRA contrast agent was prepared through ligand exchange of ultra-small NaGdF4 nanocrystals synthesized via a high temperature method,with biocompatible polyethylene glycol(PEG-dp)ligands.The basic structure,morphology,size distribution,and relaxation rate of the NaGdF4 nano contrast agent were characterized using transmission electron microscopy(TEM),a particle size potential analyzer,and a 7.0 T small-animal MRI scanner.A total of 6 healthy male SPF-grade BALB/c mice were selected and randomly divided into two groups,a NaGdF4 group and a Gd-DTPA group.The mice in the two groups were injected with NaGdF4 nanoparticle contrast agent or clinical Gd-DTPA contrast agent(0.1 mmol Gd3+/kg)via the tail vein.MRA images were obtained using a 7.0 T small animal magnetic resonance imaging system before and after the injection.A total of 6 healthy male SPF-grade Sprague Dawley(SD)rats were selected to establish a right middle cerebral artery occlusion(rMCAO)model to simulate ischemic stroke.The rats were injected with NaGdF4 nano-contrast agent(0.1 mmol Gd3+/kg)via the tail vein.Before and after the injection,brain MRI images of the rats were obtained using a 7.0 T small animal magnetic resonance imaging system.The in vitro and in vivo biological safety of the nano contrast agent was verified through cytotoxicity and hemolysis experiments and HE staining.Results Uniform spherical oil-phase NaGdF4 nanocrystals with an average particle size of approximately(4.43±0.46)nm were successfully prepared.After ligand exchange,biocompatible water-phase nanocrystals were obtained with a hydrodynamic size of 16.1 nm and a surface potential of-1.9 mV.The relaxation performance of this nanocrystal contrast agent was significantly superior to that of the clinical contrast agent Gd-DTPA.The longitudinal molar relaxivity rate(r1)of the NaGdF4 nano contrast agent was 8.84 mM-1s-1,while the transverse molar relaxivity rate(r2)was 27.36 mM-1s-1,which were 1.96 times(4.52 mM-1s-1)and 3.37 times(8.13 mM-1s-1)those of Gd-DTPA,respectively.It also demonstrated excellent biocompatibility.NaGdF4-enhanced MRA achieved high-resolution vascular imaging and effectively enabled the differentiation of the ischemic area,infarct core,and ischemic penumbra in an animal model of ischemic stroke.Conclusion The multi-parameter MRA based on NaGdF4 nanoparticles provides critical imaging evidence for the clinical diagnosis and prognosis of ischemic stroke.