It has been demonstrated that long-term space flights have a significantly greater impact on the cardiovascular, skeletal, and nervous systems of astronauts. The structural and functional alterations in the skeletal and muscular systems resulting from exposure to weightlessness can lead to the development of low back pain, significantly impairing the ability of astronauts to perform tasks and respond to emergencies. Both space flight and simulated microgravity have been shown to result in low back pain among astronauts, with the following factors identified as primary contributors to this phenomenon. The occurrence of intervertebral disc (IVD) edema results in the stimulation of type IV mechanoreceptors, which subsequently activate nociceptive afferents. The protrusion of an IVD causes compression of the spinal nerve roots. Furthermore, the elongation of the vertebral column and/or the diminished lumbar curvature of the spine exert traction on the dorsal root nerves. Paravertebral muscle degeneration leads to the inhibition of decreased nociceptive activity of the wide-dynamic range neurons of the spinal dorsal horn. Moreover, endogenous pain descending facilitation triggered by conditioning stimulation can be enhanced via the thalamic mediodorsal nuclei, while endogenous pain descending inhibition triggered by conditioning stimulation can be weakened via the thalamic ventromedial nuclei. Psychological factors may contribute to the development of low back pain. The mechanisms governing the generation, maintenance, and alleviation of low back pain in weightlessness differ from those observed in normal gravitational environments. This presents a significant challenge for space medicine research. Therefore, the elucidation of the occurrence and development mechanism of low back pain in weightlessness is important for the prevention and treatment during space flight. To reduce the incidence of low back pain during long-term missions on the space station, astronauts may choose to wear specialized space clothing that can provide axial physiological loads, designed to stimulate both musculature and skeletal structures, mitigating potential increases in vertebral column length, diminished lumbar curvature, and intervertebral disc edema and/or muscular atrophy. Additionally, assuming a “fetal tuck position” described as the knees to chest position may increase lumbar IVD hydrostatic pressure, subsequently reducing disc volume, rectifying diminished lumbar curvature, and alleviating dorsal root nerve tensions. Moreover, this position may reduce type IV mechanoreceptor facilitation and nerve impulse propagation from the sinuvertebral nerves of the annulus fibrosus. Elongated posterior soft tissues (apophyseal joint capsules and ligaments) with spinal flexion may potentially stimulate type I and II mechanoreceptors. It is also recommended to exercise the paraspinal muscles to prevent and alleviate the decrease in their cross-sectional area and maintain their structure and function. Photobiomodulation has been proved to be an effective means of activating the pain descending inhibition pathway of the central nervous system. In addition, astronauts should be encouraged to participate in mission-related activities and strive to avoid psychological problems caused by the long-term confinement in a small space station. The article presents a concise review of potential causes and targeted treatment strategies for low back pain induced by space flight or simulated microgravity in recent years. Its objective is to further elucidate the mechanisms underlying the occurrence and development of low back pain in weightless environments while providing scientific evidence to inform the development of guidelines for preventing, treating, and rehabilitating low back pain during long-term space flights.

OBJECTIVE To explore the effect and mechanism of Prunus mume against hepatic fibrosis （HF）. METHODS Male SD rats were randomly divided into normal control group （n＝10） and modeling group （n＝50）. The modeling group established HF model using carbon tetrachloride. The modeled rats were randomly divided into model group （normal saline）， positive control group [colchicine， 0.09 mg/（kg·d）]， and P. mume low-dose， medium-dose and high-dose groups [1.35， 2.70， 5.40 g/（kg·d）]， with 9 rats in each group. They were given the corresponding drug/normal saline intragastrically， once a day， for 8 consecutive weeks. After the last medication， the liver index was calculated， while liver function indexes， liver fiber indexes， oxidative stress indicators and inflammatory factors of rats were measured. HE staining was used to observe the pathological changes in liver tissue of rats； Masson staining was used to observe the degree of HF in liver tissue of rats； transmission electron microscopy was used to observe the ultrastructure of liver tissue in rats； TUNEL staining was used to detect liver cell apoptosis in each group of rats. Western blot method was used to detect the protein expressions of transforming growth factor-β1 （TGF-β1） and platelet-derived growth factor （PDGF） in liver tissue of rats. RESULTS Compared with normal control group， the levels of alanine transaminase， alkaline phosphatase， aspartate transaminase， total bilirubin， malondialdehyde， procollagen type Ⅲ protein， Ⅳ-type pre collagenase， laminin， hyaluronic acid， interleukin-6， tumor necrosis factor-α， as well as the protein expressions of TGF-β1 and PDGF in model group were increased significantly， while the levels of superoxide dismutase and glutathione peroxidase were significantly reduced （P＜0.01）； the HE， Masson staining and transmission electron microscopy observation results showed obvious HF characteristics in rats of model group. Compared with model group， varying degrees of improvement in above indexes were observed in P. mume groups， and the above 2021BSZR011） indicators of rats in P. mume medium-dose and high-dose groups were reversed significantly （P＜0.05 or P＜0.01）. CONCLUSIONS P. mume has an anti-HF effect， which may be achieved through mechanisms such as antioxidation， anti-inflammation， reduction of collagen production， inhibition of PDGF protein expression， and regulation of TGF- β1 signaling pathway.

OBJECTIVE To explore the effect and mechanism of Prunus mume against hepatic fibrosis （HF）. METHODS Male SD rats were randomly divided into normal control group （n＝10） and modeling group （n＝50）. The modeling group established HF model using carbon tetrachloride. The modeled rats were randomly divided into model group （normal saline）， positive control group [colchicine， 0.09 mg/（kg·d）]， and P. mume low-dose， medium-dose and high-dose groups [1.35， 2.70， 5.40 g/（kg·d）]， with 9 rats in each group. They were given the corresponding drug/normal saline intragastrically， once a day， for 8 consecutive weeks. After the last medication， the liver index was calculated， while liver function indexes， liver fiber indexes， oxidative stress indicators and inflammatory factors of rats were measured. HE staining was used to observe the pathological changes in liver tissue of rats； Masson staining was used to observe the degree of HF in liver tissue of rats； transmission electron microscopy was used to observe the ultrastructure of liver tissue in rats； TUNEL staining was used to detect liver cell apoptosis in each group of rats. Western blot method was used to detect the protein expressions of transforming growth factor-β1 （TGF-β1） and platelet-derived growth factor （PDGF） in liver tissue of rats. RESULTS Compared with normal control group， the levels of alanine transaminase， alkaline phosphatase， aspartate transaminase， total bilirubin， malondialdehyde， procollagen type Ⅲ protein， Ⅳ-type pre collagenase， laminin， hyaluronic acid， interleukin-6， tumor necrosis factor-α， as well as the protein expressions of TGF-β1 and PDGF in model group were increased significantly， while the levels of superoxide dismutase and glutathione peroxidase were significantly reduced （P＜0.01）； the HE， Masson staining and transmission electron microscopy observation results showed obvious HF characteristics in rats of model group. Compared with model group， varying degrees of improvement in above indexes were observed in P. mume groups， and the above 2021BSZR011） indicators of rats in P. mume medium-dose and high-dose groups were reversed significantly （P＜0.05 or P＜0.01）. CONCLUSIONS P. mume has an anti-HF effect， which may be achieved through mechanisms such as antioxidation， anti-inflammation， reduction of collagen production， inhibition of PDGF protein expression， and regulation of TGF- β1 signaling pathway.

Objective To analyze the influencing factors for postoperative anastomotic leak (AL) in carcinoma of the esophagus and gastroesophageal junction and construct a nomogram predictive model. Methods The patients who underwent radical esophagectomy at Jinling Hospital Affiliated to Nanjing University School of Medicine from January 2018 to June 2020 were included in this study. Relevant variables were screened using univariate and multivariate logistic regression analyses. A nomogram was then developed to predict the risk factors associated with postoperative AL. The predictive performance of the nomogram was validated using the receiver operating characteristic (ROC) curve. Results A total of 468 patients with carcinoma of the esophagus and gastroesophageal junction were included in the study, comprising 354 males and 114 females, with a mean age of (62.8±7.2) years. The tumors were predominantly located in the middle or lower esophagus, and 51 (10.90%) patients experienced postoperative AL. Univariate logistic regression analysis indicated that age, body mass index (BMI), tumor location, preoperative albumin levels, diabetes mellitus, anastomosis technique, anastomosis site, and C-reactive protein (CRP) levels were potentially associated with AL (P<0.05). Multivariate logistic regression analysis identified age, BMI, tumor location, diabetes mellitus, anastomosis technique, and CRP levels as independent risk factors for AL (P<0.05). A nomogram was developed based on the findings from the multivariate logistic regression analysis. The area under the receiver operating characteristic (ROC) curve was 0.803, indicating a strong concordance between the actual observations and the predicted outcomes. Furthermore, decision curve analysis demonstrated that the newly established nomogram holds significant value for clinical decision-making. Conclusion The predictive model for postoperative AL in patients with carcinoma of the esophagus and gastroesophageal junction demonstrates strong predictive validity and is essential for guiding clinical monitoring, early detection, and preventive strategies.

Objective To assess the risk of hearing loss caused by occupational noise exposure in workers in an automobile manufacturing plant in Tianjin, China, and to perform risk management. Methods Occupational health field investigation and noise exposure measurements were conducted from July to December 2023, and physical examination data were collected. ISO 1999:2013(E) Acoustics-Estimation of Noise-Induced Hearing Loss and WS/T 754-2016 ^“Guidelines for Risk Management of Occupational Disease Hazards Caused by Noise^” were used to predict the risk of high-frequency hearing loss and occupational noise induced deafness for operational workers and make a risk classification. Results The noise intensity of each workshop was 79.4 to 95.5 dB(A), and the maximum noise intensity of welding and stamping exceeded the standard. The results of the assessment showed that the noise level remained unchanged, and the risk of HFHL and ONID in workers increased as the predicted age and length of service increased. It was predicted that after the age of 40, the maximum risk of hearing loss in welding workers would be high risk, and the risk of stamping workers would be at higher risk, suggesting that welding and stamping were the key control posts of noise hazards in the enterprise. The N50 prediction values of permanent hearing threshold displacement caused by potential noise at all frequencies for final assembly and painting workers were lower than the measured values. Conclusion The consequences of hearing loss for workers in the welding and stamping shop noise operations at this automobile manufacturing plant are relatively serious and require risk management.

ObjectiveTo investigate the effects of Shenxiong Huanglian Jiedu decoction on the clearance of amyloid β-protein （Aβ） and neuronal damage in the mouse model of Alzheimer's disease （AD）. MethodsA total of 36 SPF-grade 2-month-old C57BL/6J mice were used in this study， and the modeling was performed by bilateral hippocampal injection of Aβ oligomers in C57BL/6J mice. The experiment was conducted with a blank group， a sham operation group， a model group， low- and high-dose （3.27，6.54 g·kg^-1， respectively） Shenxiong Huanglian Jiedu decoction groups， and a positive control （donepezil hydrochloride， 0.65 mg·kg^-1） group. At the end of the drug intervention， the learning and memory abilities and the activities of mice were evaluated by the Morris water maze and open field tests. Brain histopathology was examined by hematoxylin-eosin and Nissl staining. Additionally， in vivo imaging was employed to measure the metabolism of fluorescent Aβ in the cerebrospinal fluid， and staining of ionized calcium-binding adapter molecule-1 （Iba-1） was employed to assess microglial activation in the hippocampal tissue. Additionally， neurotrophin-3 （NT-3） and brain-derived neurotrophic factor （BDNF） levels in the brain tissue and serum were determined by the immunofluorescence assay and enzyme-linked immunosorbent assay. Western blot was conducted to determine the expression of inflammation and pathway-related proteins in the hippocampal tissue. ResultsCompared with the blank group and the sham operation group， the escape latency of the mice in the model group was prolonged， the platform residence time was shortened， the hippocampal tissue showed pathological manifestations such as neuronal pyknosis， Nissl body dissolution， and microglia activation. The metabolic rate of fluorescent Aβ through cerebrospinal fluid was slowed down， and the expression levels of BDNF， NT-3， and interleukin-10 （IL-10） in the hippocampus were significantly decreased （P<0.01）. The expression levels of tumor necrosis factor-α （TNF-α）， interleukin-6 （IL-6）， interleukin-1β （IL-1β）， Toll-like receptor 4 （TLR4）， myeloid differentiation factor 88 （MyD88） and phosphorylated nuclear transcription factor-κB （p-NF-κB p65） in hippocampus were significantly increased （P<0.05， P<0.01）. Compared with the model group， the escape latency of mice in the low and high dose groups of Chinese medicine and donepezil group was shortened， and the platform residence time was prolonged. Neuronal karyopyknosis， Nissl body dissolution and microglia activation in hippocampus were improved. Fluorescence Aβ was metabolized faster by cerebrospinal fluid. The expression of BDNF and NT-3 in hippocampus was increased （P<0.01）， and the expression of TLR4， MyD88 and p-NF-κB p65 was significantly decreased （P<0.05， P<0.01）. The expression of TNF-α in the hippocampus of the high-dose group was significantly decreased （P<0.05）， and the expression of IL-10 was significantly increased （P<0.05）. The expression of TNF-α， IL-6 and IL-1β in the hippocampus of the donepezil group was significantly decreased （P<0.05， P<0.01）. ConclusionShenxiong Huanglian Jiedu decoction may mitigate neuronal damage and enhance cerebrospinal fluid flow in the mouse model of AD， thereby promoting the clearance of Aβ and improving the learning and memory abilities. These beneficial effects are likely mediated through the inhibition of microglial activation， reduction of inflammation， and modulation of the TLR4/MyD88/NF-κB signaling pathway.

ObjectiveTo investigate the effects of Shenxiong Huanglian Jiedu decoction on the clearance of amyloid β-protein （Aβ） and neuronal damage in the mouse model of Alzheimer's disease （AD）. MethodsA total of 36 SPF-grade 2-month-old C57BL/6J mice were used in this study， and the modeling was performed by bilateral hippocampal injection of Aβ oligomers in C57BL/6J mice. The experiment was conducted with a blank group， a sham operation group， a model group， low- and high-dose （3.27，6.54 g·kg^-1， respectively） Shenxiong Huanglian Jiedu decoction groups， and a positive control （donepezil hydrochloride， 0.65 mg·kg^-1） group. At the end of the drug intervention， the learning and memory abilities and the activities of mice were evaluated by the Morris water maze and open field tests. Brain histopathology was examined by hematoxylin-eosin and Nissl staining. Additionally， in vivo imaging was employed to measure the metabolism of fluorescent Aβ in the cerebrospinal fluid， and staining of ionized calcium-binding adapter molecule-1 （Iba-1） was employed to assess microglial activation in the hippocampal tissue. Additionally， neurotrophin-3 （NT-3） and brain-derived neurotrophic factor （BDNF） levels in the brain tissue and serum were determined by the immunofluorescence assay and enzyme-linked immunosorbent assay. Western blot was conducted to determine the expression of inflammation and pathway-related proteins in the hippocampal tissue. ResultsCompared with the blank group and the sham operation group， the escape latency of the mice in the model group was prolonged， the platform residence time was shortened， the hippocampal tissue showed pathological manifestations such as neuronal pyknosis， Nissl body dissolution， and microglia activation. The metabolic rate of fluorescent Aβ through cerebrospinal fluid was slowed down， and the expression levels of BDNF， NT-3， and interleukin-10 （IL-10） in the hippocampus were significantly decreased （P<0.01）. The expression levels of tumor necrosis factor-α （TNF-α）， interleukin-6 （IL-6）， interleukin-1β （IL-1β）， Toll-like receptor 4 （TLR4）， myeloid differentiation factor 88 （MyD88） and phosphorylated nuclear transcription factor-κB （p-NF-κB p65） in hippocampus were significantly increased （P<0.05， P<0.01）. Compared with the model group， the escape latency of mice in the low and high dose groups of Chinese medicine and donepezil group was shortened， and the platform residence time was prolonged. Neuronal karyopyknosis， Nissl body dissolution and microglia activation in hippocampus were improved. Fluorescence Aβ was metabolized faster by cerebrospinal fluid. The expression of BDNF and NT-3 in hippocampus was increased （P<0.01）， and the expression of TLR4， MyD88 and p-NF-κB p65 was significantly decreased （P<0.05， P<0.01）. The expression of TNF-α in the hippocampus of the high-dose group was significantly decreased （P<0.05）， and the expression of IL-10 was significantly increased （P<0.05）. The expression of TNF-α， IL-6 and IL-1β in the hippocampus of the donepezil group was significantly decreased （P<0.05， P<0.01）. ConclusionShenxiong Huanglian Jiedu decoction may mitigate neuronal damage and enhance cerebrospinal fluid flow in the mouse model of AD， thereby promoting the clearance of Aβ and improving the learning and memory abilities. These beneficial effects are likely mediated through the inhibition of microglial activation， reduction of inflammation， and modulation of the TLR4/MyD88/NF-κB signaling pathway.

Metabolic-associated fatty liver disease (MAFLD) and osteoporosis (OP) are two very common metabolic diseases. A growing body of experimental evidence supports a pathophysiological link between MAFLD and OP. MAFLD is often associated with the development of OP. Rutaecarpine (RUT) is one of the main active components of Chinese medicine Euodiae Fructus. Our previous studies have demonstrated that RUT has lipid-lowering, anti-inflammatory and anti-atherosclerotic effects, and can improve the OP of rats. However, whether RUT can improve both fatty liver and OP symptoms of MAFLD mice at the same time remains to be investigated. In this study, we used C57BL/6 mice fed a high-fat diet (HFD) for 4 months to construct a MAFLD model, and gave the mice a low dose (5 mg·kg^-1) and a high dose (15 mg·kg^-1) of RUT by gavage for 4 weeks. The effects of RUT on liver steatosis and bone metabolism were then evaluated at the end of the experiment [this experiment was approved by the Experimental Animal Ethics Committee of Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences (approval number: IMB-20190124D₃03)]. The results showed that RUT treatment significantly reduced hepatic steatosis and lipid accumulation, and significantly reduced bone loss and promoted bone formation. In summary, this study shows that RUT has an effect of improving fatty liver and OP in MAFLD mice.

To investigate the awareness of cognitive impairment disorders among residents of the Xizang Autonomous Region and its influencing factors, thereby providing a basis for targeted prevention and treatment efforts.

Objective: This study aims to explore the influencing factors, formation mechanisms, and treatment methods of labial protuberance in the anterior maxilla during orthodontic treatment, providing a reference for clinical practice. Method: This study reports a case where the absence of upper anterior teeth 11 and 21, and the retraction tilting movement of teeth 12 and 22, resulted in labial protuberance and gingival hyperplasia. Alveolar osteoplasty and gingivoplasty were performed. The specific changes in the alveolar bone during the retraction of the anterior teeth and the characteristics of its remodeling were analyzed. Combined with relevant literature, the factors influencing the formation of labial protuberance in orthodontic patients, mechanisms, and methods for prevention and treatment were summarized. Results: After periodental surgery follow-up for 6 months, the gingival color and shape of teeth 12 and 22 were good, the labial alveolar bone was normal, and the overall condition was stable. A review of the literature showed that labial protuberance is more common in adult orthodontic patients, and the distance (>4 mm) and speed of retraction of anterior teeth are related to its formation, with the main mechanism likely being differential remodeling of the alveolar bone. In adult patients, the number of active osteoblasts and osteoclasts in the alveolar bone decreases, along with a reduction in metabolic activity and overall cellular activity, which diminishes the reactivity of the alveolar bone. After treatment of anterior teeth retraction, there is insufficient labial bone resorption. Moreover, the lack of mechanical stress-mediated periodontal ligament in the interdental space leads to reduced bone remodeling stimulation in this area, resulting in thickening of the labial alveolar bone of the upper anterior teeth. The remodeling rates of cortical and trabecular bone differ, with active trabecular bone proliferation near the tooth root surface and slow cortical bone resorption near the outer surface, which ultimately results in increased bone thickness at the labial cervical region. Specific case analysis indicates that the retraction distance of the upper anterior teeth in this case was about 6 mm. The alveolar bone at the missing sites of teeth 11 and 21, lacking periodontal ligament stimulation, showed less remodeling and absorption, likely appearing as hyperplasia. The prevention of labial bone protrusion mainly involves controlling the speed and distance of retraction of anterior teeth. Smaller labial protuberances generally do not require treatment, but those affecting function and aesthetics can be addressed with periodontal alveolar osteoplasty. Conclusion After the retraction of anterior teeth in orthodontics, a prominent, hard bone protuberance on the labial side can sometimes occur, which may be due to differential remodeling efficiency in different regions of the alveolar bone. For bone protuberance that influences aesthetics or function, periodontal alveolar osteoplasty can be a reliable option.