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.

Five flavonoid glycosides were isolated from the methanol and ethyl acetate fractions of the ethanol extract of Diphylleia sinensi by using various chromatographic methods, including silica gel, MCI gel, Sephadex LH-20, ODS and semi-preparative HPLC. The structures of the isolated compounds were identified as diphyflavonoid A (1), diphyflavonoid B (2), quercetin-3-O-β-D-glucopyranoside (3), kaempferol-3-O-β-D-glucopyranoside (4), kaempferol-3-O-(6″-O-acetyl)-β-D-glucopyranoside (5) by spectroscopy methods (1D NMR, 2D NMR, UV, IR, and MS). Compounds 1 and 2 were two new flavonoid glycosides, and compounds 3 and 5 were isolated from the genus Diphylleia for the first time.

Acute cerebral infarction(ACI)has the characteristics of onset nasty and high mortality,and thus the rapid determination of the occurrence and development of ACI plays a key role in the diagnosis,treatment and prognosis of ACI patients.It has shown that the serum level of human haptoglobin(Hp)is related to ACI.In this study,surface enhanced Raman scattering(SERS)combined with immune recognition was applied to establish a quantitative analysis method for serum Hp.Firstly,the SERS substrate of silver nanoparticles was prepared on silicon wafer,and 4-mercaptobenzoic Acid(MBA)was used as a Raman probe by forming Ag—S bond and connecting it on the surface of nanoparticles.The carboxyl group of MBA was linked to amino group of self-made high-affinity antibody through forming CO—NH structure thus forming a SERS self-assembled chip of Hp(Ag/MBA/anti-Hp).Hp in serum could be specifically captured by antibodies on SERS substrate,which caused the shift of SERS characteristic peak of MBA.The results showed that there was a good linear relationship between the logarithm of Hp concentration and the SERS characteristic peak shift of MBA.The detection range was 1-1000 ng/mL(R2=0.988).The Hp concentrations in serum of 90 ACI patients were determined by this method,and the results were consistent with those of ELISA method,which proved the practicability and accuracy of this method.This method was highly specific,simple and convenient,which could realize the specific recognition and quantitative analysis of serum Hp,so as to be an effective means for clinical detection of serum Hp,thus providing a reference for the treatment and prognosis of ACI.

Objective:To investigate the indications and effects of arthroscopic all-inside reconstruction in the treatment of isolated posterior cruciate ligament (PCL) injury.Methods:A retrospective analysis was performed on 47 patients with isolated PCL injury, who underwent arthroscopic all-inside reconstruction in the Third Medical Center of the PLA General Hospital from January 2016 to January 2020. There were 39 males and 8 females, aged 27.14±7.70 years old (range 16-40 years old). The preoperative kneeling-position stress X-ray showed that the degree of tibial posterior displacement was 8-10 mm, which was a complete and isolated Grade II PCL injury. The tibial and femoral tunnels were created through posterior-medial, anteromedial, and anterolateral portals, while the lateral portal to the medial femoral condyle was enlarged to position the tibial tunnel and protect the anterior cruciate ligament. The autologous graft tendon was pulled through the femoral and tibial tunnels secured with an adjustable loop plate. The efficacy was evaluated by evaluating and comparing preoperative and postoperative Lachman test, posterior drawer test, knee range of motion and relaxation, pain visual analogue scale (VAS) and Lysholm score.Results:43 patients were followed up for 35.21±3.88 months (range 12-40 months). The symptoms of knee instability all improved after surgery. At the follow-up of 1 year after surgery, 41 (95%) and 40 (93%) patients showed normal or I-degree laxity in Lachman test and posterior drawer test, respectively. The active range of motion and passive flexion of the knee joint were increased to 90°-110° and 110°-130°, respectively. The Lysholm score was 86.44±4.08 at the first year of follow-up and 90.12±3.33 at the last follow-up with significant difference compared with pre-operations ( P<0.05). The VAS score was 2.07±0.94 at the first year of follow-up and 1.28±0.83 at the last follow-up with significant difference compared with pre-operations ( P<0.05). The Lysholm score and VAS were 90.12±3.33 and 1.28±0.83, which were significantly improved compared to 1-year-follow-up ( P<0.05). Conclusion:Routine kneeling stress X-rays can evaluate the degree of tibial posterior displacement in isolated PCL injuries. With tibial posterior displacement equal to or greater than 10 mm, surgical reconstruction was required. All-inside reconstruction of isolated PCL injury was a safe and minimally invasive surgery to improve symptoms and restore knee functions.

Objective To analyze the cognition level of health care workers(HCWs)and the management status of various levels of medical institutions towards allergy reactions to commonly used antimicrobial agents.Methods HCWs and clinical pharmacists who were related to the diagnosis and treatment of antimicrobial agents in 14 medical institutions of city-level and autonomous prefectures in Gansu Province were randomly selected for a questionnaire survey.The survey contents included respondents'basic information,criteria for judging antimicrobial allergy,awareness on procedures related to antimicrobial allergy,and antimicrobial management level of different levels of medical institutions.Results A total of 8 670 valid questionnaires from HCWs were collected,including 3 300 phy-sicians,5 024 nurses and 328 pharmacists.160,775,2 123 and 5 612 HCWs were with senior,associate,interme-diate and junior professional titles,respectively.87.66％of the HCWs received relevant training on antimicrobial management in the past two years,the proportion of HCWs from different levels of medical institutions who have received training on antimicrobial management in the past two years was statistically significant different(x2=42.668,P＜0.001).HCWs with senior professional titles had the highest proportion of receiving relevant training(93.75％),there was a statistically significant difference in the proportion of receiving antimicrobial management training among HCWs with different professional titles in the past two years(x2=69.782,P＜0.001).50.98％of HCWs were not clear about penicillin allergy,and most of whom were with junior professional titles,accounting for 68.52％.25.19％of HCWs expressed uncertainty about whether patients with penicillin allergy could use cephalosporins,225 of whom were with associate professional titles,accounting for 29.03％of the total number of HCWs with associate profe-ssional titles.6.11％of HCWs had no experience in skin test procedure;46.94％of HCWs expressed that their medical institutions had no or unclear about whether their medical institutions had an antimicrobial allergy assess-ment team.Conclusion HCWs'judgment on allergy reactions to commonly used antimicrobial agents and aware-ness on antimicrobial application is not high enough,and the overall management level of antimicrobial allergy in all levels of medical institutions is poor.The popularity of antimicrobial allergy assessment teams is not high,and there is an urgent need to strengthen supervision,management,training,et al.

Objective To analyze the incidence and risk factors of hypothermia in elderly patients with malnutrition during proximal femoral nail antirotation(PFNA)internal fixation under general anesthesia.Methods A total of 139 elderly patients underwent PFNA internal fixation under general anesthesia were selected,and the nutritional status scores 1 day before surgery ranged from 0 to 11 points.Univariate and multivariate Logistic binary regression analysis was performed to analyze the related factors that may lead to intraoperative hypothermia.Results Among 139 elderly patients with preoperative nutritional scores of 0 to 11 points,79 cases(56.83%)developed intraoperative hypothermia.The results of univariate and multivariate Logistic binary regression analysis suggested that age≥75 years old,mini nutritional assessment short form(MNA-SF)nutritional score 0 to 7 points,BMI<18.5 kg/m2,duration of general anesthesia≥2 hours,intraoperative flushing fluid volume≥1 000 mL and intraoperative fluid volume≥1 000 mL were the risk factors for the occurrence of intraoperative hypothermia in elderly patients(OR>1,P<0.05).The use of warm blanket insulation was the protective factor against the occurrence of intraoperative hypothermia(OR<1,P<0.05).Conclusion The incidence of intraoperative hypothermia during PFNA internal fixation under general anesthesia in elderly patients with mainutrition before operation is high,and patients with poor nutritional status are more likely to develop intraoperative hypothermia.Patients with older age,poor nutritional status,lower BMI,longer duration of general anesthesia,and more intraoperative flushing fluid volume and intraoperative fluid volume are likely to lead to intraoperative hypothermia.The use of warm blanket can reduce the incidence of intraoperative hypothermia.

Objective To explore the value of ultrasonic quantitative measurement of hepatorenal index(HRI)for diagnosing non-alcoholic fatty liver disease(NAFLD)in children.Methods Abdominal ultrasound and upper abdominal MRI data of 70 obese children were retrospectively analyzed.ROI with different sizes and shapes of liver and right kidney were delineated on longitudinal and transverse ultrasound images,respectively,and the echo intensity of ROIs were measured to obtain HRIsmall ROI on longitudinal section,HRIsmall ROI on transverse section,HRIlarge ROI on longitudinal section and HRIlarge ROI on transverse section,i.e.HRI1,HRI2,HRI3,HRI4,while the gray,skewness and kurtosis of liver ultrasound image were recorded.Liver proton density fat fraction(PDFF)were measured based on MRI,and NAFLD was diagnoses taken PDFF≥6%as standard.The correlations of HRI with PDFF and liver ultrasound image related parameters were analyzed.Taken MRI as the standard,receiver operating characteristic(ROC)curve was drawn to evaluate the diagnostic efficacy of HRI for NAFLD.Multivariate logistic regression analysis was performed taken age,sex,body mass index(BMI)percentile,HRI3 and liver ultrasound image related parameters as independent variables and MRI diagnosis of NAFLD as dependent variable to screen the predictors of MRI diagnosis of NAFLD.Results HRI1,HRI2,HRI3 and HRI4 obtained with ultrasound was 1.89±0.52,1.88±0.55,1.97±0.51 and 1.92±0.55,respectively.PDFF obtained with MRI was(12.53±3.14)%,and diagnosed NAFLD in 34 cases.HRI and PDFF had moderate positive correlation(r=0.51-0.61,all P＜0.01).The correlation between HRI3 and PDFF was the strongest(r=0.61),and HRI3 was weakly correlated with liver gray3(r=-0.270,P=0.020),with area under the curve(AUC)for diagnosing NAFLD of 0.93(P＜0.01).BMI percentile(OR=1.06),HRI3(OR=34.20)and liver gray3(OR=0.79)were all predictive factors for MRI diagnosis of NAFLD.Conclusion Ultrasonic quantitative measurement of HRI had high clinical value for diagnosing NAFLD in children.

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.

Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA),and Acinetobacter baumannii(AB)in the bloodstream based on recombinant human mannan-binding lectin protein(M1 protein)-conjugated magnetic bead(M1 bead)enrichment of pathogens combined with RAP. Methods Recombinant plasmids were used to evaluate the assay sensitivity.Common blood influenza bacteria were used for the specific detection.Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR(M-RAP)and quantitative PCR(qPCR)assays.Kappa analysis was used to evaluate the consistency between the two assays. Results The M-RAP method had sensitivity rates of 1,10,and 1 copies/μL for the detection of SA,PA,and AB plasmids,respectively,without cross-reaction to other bacterial species.The M-RAP assay obtained results for<10 CFU/mL pathogens in the blood within 4 h,with higher sensitivity than qPCR.M-RAP and qPCR for SA,PA,and AB yielded Kappa values of 0.839,0.815,and 0.856,respectively(P<0.05). Conclusion An M-RAP assay for SA,PA,and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.

Objective In this study,we analyzed the transcriptome sequences of Kupffer cells exposed to simulated microgravity for 3 d and conducted biological experiments to determine how microgravity initiates apoptosis in Kupffer cells. Methods Rotary cell culture system was used to construct a simulated microgravity model.GO and KEGG analyses were conducted using the DAVID database.GSEA was performed using the R language.The STRING database was used to conduct PPI analysis.qPCR was used to measure the IL1B,TNFA,CASP3,CASP9,and BCL2L11 mRNA expressions.Western Blotting was performed to detect the level of proteins CASP3 and CASP 9.Flow cytometry was used to detect apoptosis and mitochondrial membrane cells.Transmission electron microscopy was used to detect changes in the ultrastructure of Kupffer cells. Results Transcriptome Sequencing indicated that simulated microgravity affected apoptosis and the inflammatory state of Kupffer cells.Simulated microgravity improved the CASP3,CASP9,and BCL2L11 expressions in Kupffer cells.Annexin-V/PI and JC-1 assays showed that simulated microgravity promoted apoptosis in Kupffer cells.Simulated microgravity causes M1 polarization in Kupffer cells. Conclusion Our study found that simulated microgravity facilitated the apoptosis of Kupffer cells through the mitochondrial pathway and activated Kupffer cells into M1 polarization,which can secrete TNFA to promote apoptosis.