BACKGROUND:The imbalance between bone resorption and bone formation in microgravity environments leads to significant bone loss in astronauts.Current research indicates that bone loss under microgravity conditions is the result of the combined effects of various cells,tissues,and systems. OBJECTIVE:To review different biological effects of microgravity on various cells,tissues,or systems,and summarize the mechanisms by which microgravity leads to the development of osteoporosis. METHODS:Databases such as PubMed,Web of Science,and the Cochrane Database were searched for relevant literature from 2000 to 2023.The inclusion criteria were all articles related to tissue engineering studies and basic research on osteoporosis caused by microgravity.Ultimately,85 articles were included for review. RESULTS AND CONCLUSION:(1)In microgravity environment,bone marrow mesenchymal stem cells tend to differentiate more into adipocytes rather than osteoblasts,and hematopoietic stem cells in this environment are more inclined to differentiate into osteoclasts,reducing differentiation into the erythroid lineage.At the same time,microgravity inhibits the proliferation and differentiation of osteoblasts,promotes apoptosis of osteoblasts,alters cell morphology,and reduces the mineralization capacity of osteoblasts.Microgravity significantly increases the number and activity of osteoclasts.Microgravity also hinders the differentiation of osteoblasts into osteocytes and promotes the apoptosis of osteocytes.(2)In a microgravity environment,the body experiences changes such as skeletal muscle atrophy,microvascular remodeling,bone microcirculation disorders,and endocrine disruption.These changes lead to mechanical unloading in the bone microenvironment,insufficient blood perfusion,and calcium cycle disorders,which significantly impact the development of osteoporosis.(3)At present,the mechanism by which microgravity causes osteoporosis is relatively complex.A deeper study of these physiological mechanisms is crucial to ensuring the health of astronauts during long-term space missions,and provides a theoretical basis for the prevention and treatment of osteoporosis.

Objective To evaluation the bioequivalence of telmisartan tablets(80 mg)between test formulation and reference formulation in Chinese healthy subjects.Methods A single-center,randomized,open-label,two-preparations,single administration,partial repeat crossover of three sequences in three postprandial cycles and complete repeat crossover of two sequences in four fasting cycles,bioequivalence test was designed.Chinese healthy subjects were included in the bioequivalence trial,with 33 randomly assigned to the postprandial group and 32 randomly assigned to the fasting group.In each period,blood samples was collected before and after administration.The plasma concentration of the drug was determined by LC-MS/MS,using WinNonlin version 8.3 calculate the pharmacokinetic parameters and perform a statistical analysis using SAS version 9.4.Results The main pharmacokinetic parameters of telmisartan tablets after oral administration of test or reference were as follows.Fasting group Cmax were(556.10±456.06)and(580.99±533.50)ng·mL-1;AUC0-t were(3 475.15±3 785.16)and(3 450.54±3 681.02)ng·mL-1·h;AUC0-∞ were(3 214.06±2 272.06)and(3 194.84±2 187.45)ng·mL-1·h.The 90％confidence intervals of the geometric mean ratio of Cmax,AUC0-t,AUC0-∞ were within the requirements of the equivalent range of bioequivalence(80.00％-125.00％).Postprandial group Cmax were(299.26±124.72)and(291.29±126.34)ng·mL-1;AUC0-t were(3 682.24±2 799.72)and(3 636.71±2 158.42)ng·mL-1·h;AUC0-were(3 544.53±1 553.06)and(3 969.38±2 528.22)ng·mL-1·h.The 90％confidence intervals of the geometric mean ratio of Cmax,AUC0-t,AUC0-∞ were within the requirements of the equivalent range of bioequivalence(80.00％-125.00％).Conclusion Under fasting and fed conditions,two kinds of telmisartan tablets are bioequivalent in Chinese healthy subjects.

Objective To explore the effect of rifampicin on the pharmacokinetics of linezolid in mice and provide pharmacokinetic evidence for the formulation of safe drugs for clinical use of pulmonary tuberculosis.Methods Fifty male KM mice were randomly divided into 2 groups:Control group,rifampicin group;the control group was given 15 mg·kg-1 linezolid;the rifampicin group was given 100 mg·mL-1 rifampicin,continuous administration for 7 days,followed by gavage,administration of 15 mg·kg-1 linezolid;blood and lung tissue were collected from mouse at different time points after administration.High performance liquid mass spectrometry(LC-MS/MS)was used to determine plasma concentration of linezolid and compared the pharmacokinetics between groups.Pharmacokinetic parameters were calculated using DAS 2.0 software.Results Main pharmacokinetic parameters of plasma linezolid in control group,rifampicin group were as follows:AUC0_t were(23.88±1.16)and(19.06±2.56)pg·mL-1·h,respectively;t1/2 were((1.15±0.11)and(1.11±0.10)h,respectively;Cmax were(9.93±0.46)and(7.74±1.17)μg·mL-1,respectively.The main pharmacokinetic parameters of the lungs in the control group and the rifampicin group were as follows:AUC0_t were(18.76±4.29)and(14.90±1.52)μg·mL-1·h,respectively;t1/2 were(1.94±0.50)and(1.44±0.07)h,respectively;Cmax were(8.28±2.67)and(6.82±1.57)μg·mL-1,respectively.AUC0_t and Cmax in plasma and AUC0_t in lung tissue of control group were significantly different from those of rifampicin group(all P＜0.05).Conclusion After the combination of rifampicin,linezolid plasma and lung tissue exposure decreased significantly,and attention should be paid to monitoring linezolid trough concentration when the two drugs were combined to avoid treatment failure caused by low effective concentration.

ObjectiveAlveolar macrophages (AMs) are critical for maintaining the homeostasis of pulmonary microenvironment. They process surfactants to ensure alveoli patency, and also serve as the first line of immune defense against pathogen invasion. Available studies have shown that monocyte-derived AMs continuously release pro-inflammatory cytokines and chemokines, recruiting other immune cells to the damaged area during pulmonary fibrosis. These monocyte-derived AMs maintains and amplifies inflammation, playing a negative role in pulmonary fibrosis progression. Current researches have predominantly focused on the gene expression levels of AMs in pulmonary fibrosis microenvironment, with less emphasis on the function and regulation of proteins. This study aims to investigate the differentially expressed proteins (DEPs) of AMs under normal physiological conditions and after pulmonary fibrosis, in order to gain a more comprehensive understanding of the role of AMs in the progression of pulmonary fibrosis. MethodsFirstly, the construction of bleomycin-induced pulmonary fibrosis mouse models was evaluated through using measurements such as body mass, lung coefficient, lungwet-to-dry mass ratio, H&E staining and Masson staining. Subsequently, AMs from both the saline controls and the pulmonary fibrosis models (2.5×10⁵ cells per sample) were collected using FACS sorting, and protein expression profiles of these cells were obtained through label-free proteomics approach. The quality of the proteomic data was assessed by comparing our saline control proteomic data with public proteomic data of physiological AMs. Thirdly, DEPs analysis between the saline controls and the bleomycin groups was carried out using R package Prostar. Functional enrichment analyses of significantly upregulated DEPs were performed using R package Clusterprofiler for GO and KEGG pathways. Finally, the STRING database was used to explore the protein-protein interaction networks related to phagocytosis regulation, inflammatory response regulation, andI-κB/NF-κB signaling pathway. The expression levels of Tlr2 and Pycard were detected respectively by FACS and western blotting. ResultsCompared to the saline controls, mice in the bleomycin groups exhibited a lower average body mass, extensive infiltration of inflammatory cells, and deposition of collagen in the lungs. This indicates that bleomycin successfully induced pulmonary fibrosis in mouse models. The proteomic data of AMs obtained from these models was of high quality and fulfilled the research requirements. A comprehensive analysis showed that 778 proteins were upregulated in pulmonary fibrosis groups compared with control groups. Moreover, the signal pathways enriched in up-regulated DEPs were related to the I‑κB/NF‑κB pathway, inflammatory response regulation, phagocytosis regulation, TGF-β signaling, and HIF-1 pathway, indicating that AMs in pulmonary fibrosis microenvironment exerted pro-inflammatory and pro-fibrotic functions. Protein-protein interaction network analysis of the DEPs suggested that the interactions between Tlr2 and Pycard were control nodes for the pro-inflammatory phenotype of AMs, thereby contributing to pulmonary fibrosis progression. Further validation by FACS and Western blotting respectively confirmed that the expression levels of Tlr2 and Pycard in AMs were significantly increased after pulmonary fibrosis. ConclusionThis study investigates the changes in the protein expression profile of AMs in the pulmonary fibrosis microenvironment. The results show that AMs notably enhanced the activity of various pathways associated with inflammation and fibrosis, suggesting that the interaction between Tlr2 and Pycard serves as a key control node for the highly pro-inflammatory behavior of AMs.

italic>Salvia miltiorrhiza, a commonly used traditional Chinese medicine, has been widely recognized for its blood-activating and stasis-removing properties in the clinical treatment of cardiovascular and cerebrovascular diseases. The synthesis and regulatory mechanism of tanshinones, the key active constituents of Salvia miltiorrhiza, have been a hot topic of research. The paper summarized the research findings on the regulation of tanshinone biosynthesis by transcription factors such as AP2/ERF, bHLH, MYB, bZIP, and WRKY in recent years. The review identifies the existing issues in the transcriptional regulation studies of Salvia miltiorrhiza and discusses the research direction of transcription factors in the regulation of tanshinone biosynthesis, providing a theoretical basis for the further discovery and utilization of functional genes involved in the regulation of tanshinone bioactive constituents.

BACKGROUND:Fluorosis is a disorder of enamel development caused by long-term intake of large amounts of fluoride during enamel development. OBJECTIVE:To further explore the molecular mechanism of dental fluorosis formation by screening the differentially expressed genes associated with calcium homeostasis in ameloblasts by transcriptome sequencing technology. METHODS:LS8 cells were treated with 0,0.4,0.8,1.6,3.2 and 6.4 mmol/L sodium fluoride(NaF)for 24,48 and 72 hours to observe the effects of different concentrations of NaF on the morphology,cell activity and intracellular Ca2+ concentration of LS8 cells.The differentially expressed genes were screened by transcriptome sequencing and validated. RESULTS AND CONCLUSION:After 24 hours of treatment,the cells treated with 0,0.4,and 0.8 mmol/L NaF were in good growth condition,with increased cell number and clear cell outline.When the NaF concentration was≥1.6 mmol/L,the cells were gradually shrunken and became smaller and the number of cells decreased with the increase of NaF concentration.After 48 and 72 hours of treatment,the number of cells increased in the 0,0.4 mmol/L NaF groups,while gradually decreased in the 0.8,1.6,3.2 mmol/L NaF groups,with rounded and smaller cell morphology.The cells in the 6.4 mmol/L NaF group were shrunken,rounded and suspended in the medium,with almost no adherent cells.When treated with the same concentration of NaF,LS8 cells were in optimal growth after 24 hours of treatment.Results from cell counting kit-8 assay showed that when treated with the same concentration of NaF,the cell activity decreased with the increase of treatment time;when the treatment time was the same,the cell activity decreased with the increase of NaF concentration.After 24 hours of treatment,the intracellular Ca2+ concentration increased with the increase of NaF concentration.Transcriptome sequencing analysis identified genes involved in the regulation of cellular calcium homeostasis:Hsp90b1,Canx,Calr,and Hspa5 that were significantly upregulated(P＜0.05)and Cacna1a that was significantly downregulated(P＜0.05).To conclude,the inhibitory effect of NaF on LS8 cell proliferation may be related to the abnormal increase in intracellular Ca2+ concentration,and the mechanism may be caused by the upregulation of the expression of protein processing and synthesis pathways Hsp90b1,Canx,Calr,and Hspa5 and the downregulation of the expression of calcium signaling pathway Cacna1a.

Objective:To explore the application of the semi-flipped classroom combined with knowledge point auction learning method in the theoretical teaching among stomatological students and its effectiveness.Methods:Undergraduates from four classes at Guanghua School of Stomatology, Sun Yat-Sen University were taken as research subjects. Students from two classes ( n=198) were taught using the semi-flipped classroom combined with the knowledge point auction learning method, while students from the other two classes ( n=172) were taught with the regular classroom teaching method as controls. Classroom quizzes were used to compare the two classes' mastery of important and difficult points, and a questionnaire was used to investigate students' feedback on the class outcomes. SPSS 22.0 was used for the independent samples t-test. Results:The mean test score of the experimental class was higher than that of the control class (88.51±11.02 vs. 80.40±8.53). The results of the questionnaire showed that students' interest in the course, comprehension and absorption of knowledge points, degree of satisfaction with the class, and mastery of the contents in sections in the experimental class were significantly higher than those in the control class (7.28±1.51 vs. 9.10±0.73, 6.92±1.44 vs. 8.69±1.62, 6.09±1.87 vs. 7.61±1.46, 6.40±1.04 vs. 7.70±0.86 ).Conclusions:The semi-flipped classroom combined with the knowledge point auction learning method is innovative and achieves good teaching outcomes. It holds promise for wider use in the theoretical teaching of various clinical subjects. To explore the application of the semi-flipped classroom combined with knowledge point auction learning method in the theoretical teaching among stomatological students and its effectiveness.

Objective To investigate the attributable risk(AR)of Acinetobacter baumannii(AB)infection in criti-cally ill patients.Methods A multicenter retrospective cohort study was conducted among adult patients in inten-sive care unit(ICU).Patients with AB isolated from sterile body fluid and confirmed with AB infection in each cen-ter were selected as the infected group.According to the matching criteria that patients should be from the same pe-riod,in the same ICU,as well as with similar APACHE Ⅱ score(±5 points)and primary diagnosis,patients who did not infect with AB were selected as the non-infected group in a 1:2 ratio.The AR was calculated.Results The in-hospital mortality of patients with AB infection in sterile body fluid was 33.3％,and that of non-infected group was 23.1％,with no statistically significant difference between the two groups(P=0.069).The AR was 10.2％(95％CI:-2.3％-22.8％).There is no statistically significant difference in mortality between non-infected pa-tients and infected patients from whose blood,cerebrospinal fluid and other specimen sources AB were isolated(P＞0.05).After infected with AB,critically ill patients with the major diagnosis of pulmonary infection had the high-est AR.There was no statistically significant difference in mortality between patients in the infected and non-infec-ted groups(P＞0.05),or between other diagnostic classifications.Conclusion The prognosis of AB infection in critically ill patients is highly overestimated,but active healthcare-associated infection control for AB in the ICU should still be carried out.

Ankylosing spondylitis (AS) combined with lower cervical fracture is often categorized into unstable fracture, with a high incidence of neurological injury and a high rate of disability and morbidity. As factors such as shoulder occlusion may affect the accuracy of X-ray imaging diagnosis, it is often easily misdiagnosed at the primary diagnosis. Non-operative treatment has complications such as bone nonunion and the possibility of secondary neurological damage, while the timing, access and choice of surgical treatment are still controversial. Currently, there are no clinical practice guidelines for the treatment of AS combined with lower cervical fracture with or without dislocation. To this end, the Spinal Trauma Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate Clinical guidelines for the treatment of ankylosing spondylitis combined with lower cervical fracture in adults ( version 2024) in accordance with the principles of evidence-based medicine, scientificity and practicality, in which 11 recommendations were put forward in terms of the diagnosis, imaging evaluation, typing and treatment, etc, to provide guidance for the diagnosis and treatment of AS combined with lower cervical fracture.

Following the principles of evidence-based medicine,in accordance with the structure and drafting rules of standardized documents,based on literature research,according to the characteristics of chronic cough in children and issues that need to form a consensus,the TCM Guidelines for Diagnosis and Treatment of Chronic Cough in Children was formulated based on the Delphi method,expert discussion meetings,and public solicitation of opinions.The guideline includes scope of application,terms and definitions,eti-ology and diagnosis,auxiliary examination,treatment,prevention and care.The aim is to clarify the optimal treatment plan of Chinese medicine in the diagnosis and treatment of this disease,and to provide guidance for improving the clinical diagnosis and treatment of chronic cough in children with Chinese medicine.