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 investigate the effects and potential mechanism of Qiangxin decoction on mitochondrion of rats with chronic heart failure （CHF）. METHODS The CHF model was established by ligating the left anterior descending branch of the coronary artery. Modeled rats were divided into model group， Qiangxin decoction low-dose and high-dose groups （12.25， 24.50 g/kg， calculated by crude drug）， and chemical medicine group （Sacubitril valsartan sodium tablets， 10.42 mg/kg）， with 10 rats in each group； control group was set up without treatment. Each group of rats was orally administered with the corresponding medication or normal saline twice a day for 28 consecutive days. After the last medication， the contents of N-terminal pro-brain natriuretic peptide （NT-proBNP） and adenosine triphosphate （ATP） in serum and phosphatidic acid （PA） and cardiolipin （CL） in myocardial tissue were all detected； the pathological damage and collagen fibrosis of rat myocardial tissue were observed； the apoptosis of myocardial cells was determined； the ultrastructure of myocardial tissue was observed； the protein expressions of mitofusin 1 （Mfn1）， Mfn2， optic atrophy protein 1 （OPA1） and dynamin-related protein 1 （Drp1） were all detected in myocardial tissue. RESULTS Compared with control group，the serum content of NT-proBNP， apoptotic rate of myocardial cells， and relative expressions of S-OPA1 and Drp1 proteins were all increased significantly； serum content of ATP，contents of PA and CL， and relative expressions of Mfn1， Mfn2 and L-OPA1 proteins were all significantly reduced （P＜0.05）. There were abnormal membrane tissue structure in various layers of myocardial tissue， degeneration and necrosis of myocardial cells， and severe fibrosis； the mitochondria were swollen， with reduced or absent cristae， and uneven matrix density. After intervention with Qiangxin decoction， the levels of the aforementioned quantitative indicators in serum and myocardial tissue of rats （excluding CL content in the Qiangxin decoction low- dose group） were significantly reversed （P＜0.05）； the pathological damage of myocardial tissue had significantly improved， fibrosis had significantly reduced， mitochondrial morphology tended to be normal， cristae had increased， and matrix density was uniform. CONCLUSIONS Qiangxin decoction can regulate myocardial mitochondrial function and structural integrity of CHF rats， thereby improving myocardial energy metabolism and antagonizing myocardial fibrosis， the mechanism of which may be associated with activating PA/Mfn/CL signaling pathway.

OBJECTIVE To investigate the effects and potential mechanism of Qiangxin decoction on mitochondrion of rats with chronic heart failure （CHF）. METHODS The CHF model was established by ligating the left anterior descending branch of the coronary artery. Modeled rats were divided into model group， Qiangxin decoction low-dose and high-dose groups （12.25， 24.50 g/kg， calculated by crude drug）， and chemical medicine group （Sacubitril valsartan sodium tablets， 10.42 mg/kg）， with 10 rats in each group； control group was set up without treatment. Each group of rats was orally administered with the corresponding medication or normal saline twice a day for 28 consecutive days. After the last medication， the contents of N-terminal pro-brain natriuretic peptide （NT-proBNP） and adenosine triphosphate （ATP） in serum and phosphatidic acid （PA） and cardiolipin （CL） in myocardial tissue were all detected； the pathological damage and collagen fibrosis of rat myocardial tissue were observed； the apoptosis of myocardial cells was determined； the ultrastructure of myocardial tissue was observed； the protein expressions of mitofusin 1 （Mfn1）， Mfn2， optic atrophy protein 1 （OPA1） and dynamin-related protein 1 （Drp1） were all detected in myocardial tissue. RESULTS Compared with control group，the serum content of NT-proBNP， apoptotic rate of myocardial cells， and relative expressions of S-OPA1 and Drp1 proteins were all increased significantly； serum content of ATP，contents of PA and CL， and relative expressions of Mfn1， Mfn2 and L-OPA1 proteins were all significantly reduced （P＜0.05）. There were abnormal membrane tissue structure in various layers of myocardial tissue， degeneration and necrosis of myocardial cells， and severe fibrosis； the mitochondria were swollen， with reduced or absent cristae， and uneven matrix density. After intervention with Qiangxin decoction， the levels of the aforementioned quantitative indicators in serum and myocardial tissue of rats （excluding CL content in the Qiangxin decoction low- dose group） were significantly reversed （P＜0.05）； the pathological damage of myocardial tissue had significantly improved， fibrosis had significantly reduced， mitochondrial morphology tended to be normal， cristae had increased， and matrix density was uniform. CONCLUSIONS Qiangxin decoction can regulate myocardial mitochondrial function and structural integrity of CHF rats， thereby improving myocardial energy metabolism and antagonizing myocardial fibrosis， the mechanism of which may be associated with activating PA/Mfn/CL signaling pathway.

Background/Aims: Obesity is associated with several gastrointestinal (GI) disorders and has been identified as a potential risk factor for various GI symptoms. Bowel frequency is an important indicator of bowel function. However, the causal link between obesity and gastrointestinal motility remains uncertain. This study aims to determine the causal effect of overall and central obesity on stool frequency. Methods: Four obesity-related anthropometric indicators–body mass index, body fat percentage, waist circumference (WC), and waist-tohip ratio (WHR)–were investigated. Individual-level baseline information from the UK Biobank was used to explore observational associations between obesity and stool frequency. Additionally, summary-level data from published genome-wide association studies were subjected to two-sample Mendelian randomization (MR) analyses to examine causal associations. Results: For all 4 indicators of obesity, higher levels of obesity were associated with more frequent bowel movements after adjusting for demographic characteristics, lifestyle, and dietary factors. After rigorous screening, 482 body mass index single nucleotide polymorphisms (SNPs), 7 body fat percentage SNPs, 48 WC SNPs, and 287 WHR SNPs were identified as instrument variables for MR analysis. The MR results were generally consistent with observational findings, proving that the associations observed in the overall obesity indicators were causal. For central obesity, the association between WHR and stool frequency remained consistent in both analysis phases, whereas WC showed a multidirectional association. Conclusions Obesity-related anthropometric indicators were causally associated with increased stool frequency in the overall and central obesity groups. Weight loss could be a potential approach to improve gastrointestinal regularity in individuals with obesity.

Background/Aims: Obesity is associated with several gastrointestinal (GI) disorders and has been identified as a potential risk factor for various GI symptoms. Bowel frequency is an important indicator of bowel function. However, the causal link between obesity and gastrointestinal motility remains uncertain. This study aims to determine the causal effect of overall and central obesity on stool frequency. Methods: Four obesity-related anthropometric indicators–body mass index, body fat percentage, waist circumference (WC), and waist-tohip ratio (WHR)–were investigated. Individual-level baseline information from the UK Biobank was used to explore observational associations between obesity and stool frequency. Additionally, summary-level data from published genome-wide association studies were subjected to two-sample Mendelian randomization (MR) analyses to examine causal associations. Results: For all 4 indicators of obesity, higher levels of obesity were associated with more frequent bowel movements after adjusting for demographic characteristics, lifestyle, and dietary factors. After rigorous screening, 482 body mass index single nucleotide polymorphisms (SNPs), 7 body fat percentage SNPs, 48 WC SNPs, and 287 WHR SNPs were identified as instrument variables for MR analysis. The MR results were generally consistent with observational findings, proving that the associations observed in the overall obesity indicators were causal. For central obesity, the association between WHR and stool frequency remained consistent in both analysis phases, whereas WC showed a multidirectional association. Conclusions Obesity-related anthropometric indicators were causally associated with increased stool frequency in the overall and central obesity groups. Weight loss could be a potential approach to improve gastrointestinal regularity in individuals with obesity.

Background/Aims: Obesity is associated with several gastrointestinal (GI) disorders and has been identified as a potential risk factor for various GI symptoms. Bowel frequency is an important indicator of bowel function. However, the causal link between obesity and gastrointestinal motility remains uncertain. This study aims to determine the causal effect of overall and central obesity on stool frequency. Methods: Four obesity-related anthropometric indicators–body mass index, body fat percentage, waist circumference (WC), and waist-tohip ratio (WHR)–were investigated. Individual-level baseline information from the UK Biobank was used to explore observational associations between obesity and stool frequency. Additionally, summary-level data from published genome-wide association studies were subjected to two-sample Mendelian randomization (MR) analyses to examine causal associations. Results: For all 4 indicators of obesity, higher levels of obesity were associated with more frequent bowel movements after adjusting for demographic characteristics, lifestyle, and dietary factors. After rigorous screening, 482 body mass index single nucleotide polymorphisms (SNPs), 7 body fat percentage SNPs, 48 WC SNPs, and 287 WHR SNPs were identified as instrument variables for MR analysis. The MR results were generally consistent with observational findings, proving that the associations observed in the overall obesity indicators were causal. For central obesity, the association between WHR and stool frequency remained consistent in both analysis phases, whereas WC showed a multidirectional association. Conclusions Obesity-related anthropometric indicators were causally associated with increased stool frequency in the overall and central obesity groups. Weight loss could be a potential approach to improve gastrointestinal regularity in individuals with obesity.

Based on the principle of molecular hybridization, fifteen compounds were designed and synthesized through the combination of aminothiazoloxime and phosphonate fragment. The results showed that these compounds had better inhibitory effects on the tested bacteria. In particular, the activities of compounds Ⅲf and Ⅲi against S. aureus, E. coli, methicillin-resistant S. aureus (MRSA) and fluoroquinolone-resistant E. coli (FREC) were the most significant, the minimal inhibitory concentration (MIC) of Ⅲf was 1, 8, 4, 16 μg·mL^-1 respectively, and the MIC of Ⅲi was 4, 4, 16, 8 μg·mL^-1 respectively, which were slightly lower than that of the control drug oxacillin, and their anti-E. coli, MRSA and FREC activities were superior to that of the control drug oxacillin. Their activities to S. aureus were close to that of oxacillin, and to E. coli, MRSA and FREC were superior to that of oxacillin, which is worthy of further study.

The inflammatory effect of dietary is strongly related to the development of cancer,therefore,the diet-related inflammatory index was developed as a methodological tool to investigate the relationship between dietary,inflammation and tumors.In this paper,we summarized the results on diet-related inflammatory indices and common cancers of the digestive system based on relevant cancer epidemiological studies.The available epidemiological evidence suggests that pro-inflammatory diet is associated with an increased risk of gastrointestinal malignancies,with the strongest association with colorectal cancer,followed by esophageal and gastric cancers,and then pancreatic cancer,and the least evidence of studies with liver cancer.Among these studies,the level of evidence for esophageal cancer is lower than colorectal cancer,the study of gastric cancer has gender differences and problems in adjusting for confounders,and the study of pancreatic cancer has heterogeneous results.In view of the current research progress and deficiencies,prospective studies or population-based cohort studies,as well as strengthening nutritional epidemiological studies related to common tumors such as liver cancer could be considered in the future.This review is expecting to provide basic information and scientific basis for strengthening the related healthy eating behavior promotion in the prevention and control of digestive system tumors.

Objective:To investigate serum vitamin A and vitamin D status in children aged 2-<7 years in 20 cities in China.Methods:A cross-sectional study was conducted. A total of 2 924 healthy children aged 2-<7 years were recruited from September 2018 to September 2019 from 20 cities in China, categorized by age groups of 2-<3 years, 3-<5 years, and 5-<7 years. The demographic and economic characteristics and health-related information of the enrolled children were investigated. Body weight and height were measured by professional staff members. The serum vitamin A and vitamin D levels were detected by high-performance liquid chromatography-tandem mass spectrometry. Chi-square test and Logistic regression were applied to analyze the association between vitamin A and vitamin D deficiency and insufficiency as well as their underlying impact factors.Results:The age of the 2 924 enrolled children was 4.33 (3.42, 5.17) years. There were 1 726 males (59.03%) and 1 198 females (40.97%). The prevalences of vitamin A and vitamin D deficiency in enrolled children were 2.19% (64/2 924) and 3.52% (103/2 924), respectively, and the insufficiency rates were 29.27% (856/2 924) and 22.20% (649/2 924), respectively. Children with both vitamin A and vitamin D deficiencies or insufficiencies were found in 10.50% (307/2 924) of cases. Both vitamin A ( χ2=7.91 and 8.06, both P=0.005) and vitamin D ( χ2=71.35 and 115.10, both P<0.001) insufficiency rates were higher in children aged 3-<5 and 5-<7 years than those in children aged 2-<3 years. Vitamin A and vitamin D supplementation in the last 3 months was a protective factor for vitamin A and D deficiency and insufficiency, respectively ( OR=0.68 and 0.22, 95% CI 0.49-0.95 and 0.13-0.40, both P<0.05). The rates of vitamin A and D insufficiency was higher in children with annual household incomes <60 000 RMB than in those with annual household incomes ≥60 000 RMB ( χ2=34.11 and 10.43, both P<0.01). Northwest and Southwest had the highest rates of vitamin A and vitamin D insufficiency in children aged 2-<7 yeas, respectively ( χ2=93.22 and 202.54, both P<0.001). Conclusions:Among 20 cities in China, children aged 2-<7 years experience high rates of vitamin A and vitamin D insufficiency, which are affected by age, family economic level, vitamin A and vitamin D supplementation, and regional economic level. The current results suggest that high level of attention should be paid to vitamin A and vitamin D nutritional status of preschool children.

Objective:To understand the current status of anemia, iron deficiency, and iron-deficiency anemia among preschool children in China.Methods:A cross-sectional study was conducted with a multi-stage stratified sampling method to select 150 streets or townships from 10 Chinese provinces, autonomous regions, or municipalities (East: Jiangsu, Zhejiang, Shandong, and Hainan; Central: Henan; West: Chongqing, Shaanxi, Guizhou, and Xinjiang; Northeast: Liaoning). From May 2022 to April 2023, a total of 21 470 children, including community-based children aged 0.5 to<3.0 years receiving child health care and kindergarten-based children aged 3.0 to<7.0 years, were surveyed. They were divided into 3 age groups: infants (0.5 to<1.0 year), toddlers (1.0 to<3.0 years), and preschoolers (3.0 to<7.0 years). Basic information such as sex and date of birth of the children was collected, and peripheral blood samples were obtained for routine blood tests and serum ferritin measurement. The prevalence rates of anemia, iron deficiency, and iron-deficiency anemia were analyzed, and the prevalence rate differences were compared among different ages, sex, urban and rural areas, and regions using the chi-square test.Results:A total of 21 460 valid responses were collected, including 10 780 boys (50.2%). The number of infants, toddlers, and preschoolers were 2 645 (12.3%), 6 244 (29.1%), and 12 571 (58.6%), respectively. The hemoglobin level was (126.7±14.8) g/L, and the serum ferritin level was 32.3 (18.5, 50.1) μg/L. The overall rates of anemia, iron deficiency, and iron-deficiency anemia were 10.4% (2 230/21 460), 28.3% (6 070/21 460), and 3.9% (845/21 460), respectively. The prevalence rate of anemia was higher for boys than for girls (10.9% (1 173/10 780) vs. 9.9% (1 057/10 680), χ2=5.58, P=0.018), with statistically significant differences in the rates for infants, toddlers and preschoolers (18.0% (475/2 645), 10.6% (662/6 244), and 8.7% (1 093/12 571), respectively, χ2=201.81, P<0.01), and the rate was significantly higher for children in rural than that in urban area (11.8% (1 516/12 883) vs. 8.3% (714/8 577), χ2=65.54, P<0.01), with statistically significant differences in the rates by region ( χ2=126.60, P<0.01), with the highest rate of 15.8% (343/2 173) for children in Central region, and the lowest rate of 5.3% (108/2 053) in Northeastern region. The prevalence rates of iron deficiency were 33.8% (895/2 645), 32.2% (2 011/6 244), and 25.2% (3 164/12 571) in infants, toddlers, and preschoolers, respectively, and 30.0% (3 229/10 780) in boys vs. 26.6% (2 841/10 680) in girls, 21.7% (1 913/8 821), 40.0% (870/2 173), 27.1% (2 283/8 413), 48.9% (1 004/2 053) in Eastern, Central, Western, and Northeastern regions, respectively, and each between-group showed a significant statistical difference ( χ2=147.71, 29.73, 773.02, all P<0.01). The prevalence rate of iron-deficiency anemia showed a significant statistical difference between urban and rural areas, 2.9% (251/8 577) vs. 4.6% (594/12 883) ( χ2=38.62, P<0.01), while the difference in iron deficiency prevalence was not significant ( χ2=0.51, P=0.476). Conclusions:There has been a notable improvement in iron deficiency and iron-deficiency anemia among preschool children in China, but the situation remains concerning. Particular attention should be paid to the prevention and control of iron deficiency and iron-deficiency anemia, especially among infants and children in the Central, Western, and Northeastern regions of China.