Abstract Upper cross syndrome (UCS) is an abnormal body posture phenomenon. The detection rate of UCS in adolescents is high in China, which has become a serious public health problem threatening the health of adolescents. Exercise therapy has a positive effect on the prevention and treatment of UCS.The article reviews the pathological mechanisms of muscle imbalance, muscle interaction inhibition, and neural control related to the occurrence and development of UCS both domestically and internationally in recent years.And it elucidates the effects and corresponding mechanisms of exercise interventions such as gentle exercise, stretching exercise and physical function training on UCS, so as to provide help for the correction of UCS.

Objective: To explore the potential classification of 24 hour activity time allocation among college students in Yinchuan and its association with active health levels, so as to provide references for optimizing activity time allocation to enhance active health levels. Methods: From November 18 to December 6, 2024, a stratified cluster random sampling method was used to select 2 422 first and second year college students from full time undergraduate institutions in Yinchuan. The Chinese College Students 24 hour Movement Behaviors Questionnaire (24 h MBQ) and Active Health Behavior Scale were used to assess 24 hour activity time allocation and evaluate active health levels. Latent profile analysis (LPA) was employed to categorize activity types, and a binary Logistic regression analysis was conducted to analyze the relationship between active health levels and activity types. Results: A total of 1 087 students (44.9%) were found of meeting active health standards, and significant statistical differences were found in active health levels across different genders, grades, academic qualities, sources of origin and academic categories ( χ 2= 22.03 , 7.65, 25.50, 10.12, 43.44, all P <0.01). Moreover, significant statistical differences could also be found among college students 24 hour activity time across different genders, ages, grades, sources of origin, academic qualities, and academic categories ( t/Z/H/F=-5.70-111.39, P <0.05).The 24 hour activity time allocation was classified into four types:academic high ( 6.9 %), low activity rest (8.8%), light activity (67.8%), and high activity dynamic (16.4%). Significant statistical differences were observed in activity time allocation categories across different ages, academic qualities and academic categories ( χ 2=15.52-108.46, all P <0.05). Using the high activity dynamic type as a reference, the light activity type ( OR=0.39, 95%CI =0.31-0.50), low activity rest type ( OR=0.10, 95%CI =0.06-0.15), and academic high type ( OR=0.03, 95%CI =0.02-0.07) had lower active health levels among college students (all P <0.01). Conclusion There is a significant difference in 24 hour activity time allocation among college students in Yinchuan, and different activity types are associated with active health levels.

Objective To investigate the application of cardiovascular magnetic resonance feature tracking(CMR-FT)in assessing myocardial strain in dilated cardiomyopathy(DCM)patients residing at high altitudes.Methods We retrospectively enrolled 29 DCM patients living at high altitudes(DCM-H),27 DCM patients living in a low-altitude plain environment(DCM-P),23 healthy volunteers living at a high altitude(HV-H),and 24 healthy volunteers living in a low-altitude plain environment(HV-P).All subjects underwent cine MRI scanning using a 3.0T rapid steady-state free precession sequence.The CMR images thus acquired were analyzed using cvi42,a post-processing software,to obtain left ventricular function and myocardial strain parameters.Results Compared with the HV-H group,the DCM-H group showed higher left ventricle end-diastolic volume(LVEDV)and left ventricle end-systolic volume(LVESV),and lower left ventricular ejection fraction(LVEF)and stroke volume(LVSV)(all P＜0.01).No significant difference was observed in cardiac function between the DCM-H and DCM-P groups(all P＞0.05).The absolute values of global radial strain(GRS),global circumferential strain(GCS),and global longitudinal strain(GLS)in the DCM-H group were lower than those in the HV-P group([14.5±6.5]％vs.[34.2±10.7]％,[-11.1±4.4]％vs.[-19.9±2.8]％,and[-7.7±3.2]％vs.[-13.6±4.1]％,respectively),with the differences being statistically significant(all P＜0.001).The DCM-H group had higher absolute GRS,GCS,and GCS values than the DCM-P group did([14.5±6.5]％vs.[7.0±2.7]％,[-11.1±4.4]％vs.[—5.4±2.2]％,and[—7.7±3.2]％vs.[—4.3±1.7]％,respectivley,all P＜0.01).Conclusion Myocardial strain in DCM patients living at a high altitude is lower than that in healthy volunteers living at a high altitude,but higher than that in DCM patients living in a low-altitude plain environment.CMR-FT can be used to quantitatively assess myocardial contractility in DCM patients living at a high altitude,showing promise for clinical application.

The quality management system verification of 67 medical device manufacturers in some region was introduced generally.The common defects during the quality management system verification of medical device manufacturerswere summarized from 11 aspects of organization and personnel,plant and facility,equipment,document management,design and development,procurement,production management,quality control and etc.The causes for the common defects were analyzed.Some countermeasures were proposed including strengthening the training and education of related personnel,continuously promoting quality management system,enhancing managment and execution mechanism and improving the mechanism of personnel participation and encouragement.References were provided for establishing and running the quality management system of medical device manufacturers.[Chinese Medical Equipment Journal,2024,45(8):83-90]

Intestinal dysbiosis and disrupted bile acid(BA)homeostasis are associated with obesity,but the precise mechanisms remain insufficiently explored.Hepatic protein phosphatase 1 regulatory subunit 3G(PPP1R3G)plays a pivotal role in regulating glycolipid metabolism;nevertheless,its obesity-combatting potency remains unclear.In this study,a substantial reduction was observed in serum PPP1R3G levels in high-body mass index(BMI)and high-fat diet(HFD)-exposed mice,establishing a positive correlation between PPP1R3G and non-12α-hydroxylated(non-12-OH)BA content.Additionally,hepatocyte-specific overexpression of Ppp1r3g(PPP1R3G HOE)mitigated HFD-induced obesity as evidenced by reduced weight,fat mass,and an improved serum lipid profile;hepatic steatosis alleviation was confirmed by normalized liver enzymes and histology.PPP1R3G HOE considerably impacted systemic BA homeostasis,which notably increased the non-12-OH BAs ratio,particularly lithocholic acid(LCA).16S ribosomal DNA(16S rDNA)sequencing assay indicated that PPP1R3G HOE reversed HFD-induced gut dysbiosis by reducing the Firmicutes/Bacteroidetes ratio and Lactobacillus population,and elevating the relative abundance of Blautia,which exhibited a positive correlation with serum LCA levels.A fecal microbiome transplantation test confirmed that the anti-obesity effect of hepatic PPP1R3G was gut microbiota-dependent.Mechanistically,PPP1R3G HOE markedly suppressed hepatic cholesterol 7α-hydroxylase(CYP7A1)and sterol-12α-hydroxylase(CYP8B1),and concurrently upregulated oxysterol 7-α hydroxylase and Takeda G protein-coupled BA receptor 5(TGR5)expression under HFD conditions.Furthermore,LCA administration significantly mitigated the HFD-induced obesity phenotype and elevated non-12-OH BA levels.These findings emphasize the significance of hepatic PPP1R3G in ameliorating diet-induced adiposity and hepatic steatosis through the gut microbiota-BA axis,which may serve as potential ther-apeutic targets for obesity-related disorders.

Purpose To explore the cardioprotective effect of cang-ai volatile oil(CAVO)on rats with cardiac function impairment model under low-pressure and low-oxygen environment in Tibet Plateau based on 7.0T cardiovascular magnetic resonance(CMR)imaging.Materials and Methods Forty SD rats were randomly divided into the normal group,the high altitude model group,the CAVO-treated group and the rhodiola rosea-treated group,with 10 rats in each group.Except for the normal group,the rats in other groups were transferred from the plain(500 m above sea level)to the Tibet Plateau(4 250 m above sea level)for two months,and then administered with the corresponding drugs by gavage for 14 d.The left ventricle function was measured by using a 7.0T high-field strength CMR and myocardial strain was analysed by using tissue tracing technique.HE staining was used to observe the morphology of cardiomyocytes,Masson staining to observe interstitial fibrosis,wheat germ agglutinin staining to observe cardiomyocyte hypertrophy,and transmission electron microscopy to observe the morphological changes of mitochondria in each group.Serum levels of creatine kinase,creatine kinase isoenzyme,lactate dehydrogenase,cardiac troponin T,superoxide dismutase,malondialdehyde and glutathione peroxidase were detected.Intracellular reactive oxygen species levels were detected using flow cytometry.Results The left ventricular ejection fraction of rats in the CAVO-treated group was higher than that of the high altitude model group[(66.61±1.38)％vs.(60.94±3.21)％;t=3.969,P=0.032];meanwhile,the global circumferential strain of the left ventricle in the CAVO-treated group was higher than that of the high altitude model group(-25.68±1.30 vs.-22.84±1.17;t=3.967,P=0.003).HE,Masson and wheat germ agglutinin staining showed hypertrophy and necrosis as well as interstitial fibrosis and ultrastructural disruption of cardiomyocytes in the high altitude model group,which improved after CAVO treatment.The level of cardiac troponin T in the serum of rats with CAVO treatment group was significantly decreased compared with that of the high altitude model group[(314.03±20.05)pg/ml vs.(518.30±18.13)pg/ml;1=13.090,P=0.001].Conclusion CAVO treatment can reduce cardiac injury caused by low-pressure hypoxia in high altitude,and its effect can be detected dynamically and non-invasively by 7.0T high-field strength CMR.

Objective To establish a hypobaric hypoxia rat model in a real high-altitude environment,to investigate the effects of the real high-altitude environment on rat bone mass and bone microstructure using multiple methods such as Micro CT,blood biochemistry,and pathology,and to explore the potential mechanisms involved.Methods Sprague Dawley(SD)rats were transported to the Yushu Plateau Laboratory(at 4250 m above sea level)in Qinghai Province and kept there for 4,or 8,or 18 months.These groups were designated as H-4,H-8,and H-18,respectively.Upon completion of the high-altitude exposure,these animals were transported to the Molecular Imaging Laboratory,West China Hospital,Sichuan University(at 500 m above sea level)in Chengdu for relevant testing and comparison with the control animals raised in a low-altitude environment for the same durations(designated L-4,L-8,and L-18).The tests performed included blood biochemistry,Micro CT imaging,and pathological assessments such as ELISA,Western blot,and HE and TRAP staining.Results Compared with that of the control group,the body mass of rats in the H-4 and H-18 groups decreased significantly(H-4 group vs.L-4 group:[513.75±35.10]g vs.[649.18±60.03]g,P＜0.01;H-18 group vs.L-18 group:[535.58±66.65]g vs.[670.86±44.96]g,P＜0.01).The serum Ca2+concentration was higher in the H-8 group and H-18 group compared to that in the control group(H-8 group vs.L-8 group:[2.48±0.09]mmol/L vs.[2.38±0.07]mmol/L,P＜0.05;H-18 group vs.L-18 group:[2.55±0.11]mmol/L vs.[2.13±0.27]mmol/L,P＜0.05).No statistically significant difference was observed in the concentration of P3+.Bone metabolism indicator cross-linked carboxy-terminal telopeptide of type Ⅰ collagen(CTX-Ⅰ)was significantly increased in all high-altitude groups compared to the low-altitude groups(H-4 group vs.L-4 group:[1.44±0.08]ng/mL vs.[0.70±0.13]ng/mL,P＜0.01;H-8 group vs.L-8 group:[1.52±0.10]ng/mL vs.[0.75±0.10]ng/mL,P＜0.01;H-18 group vs.L-18 group:[2.70±0.13]ng/mL vs.[1.94±0.15]ng/mL,P＜0.01).In addition,CT results showed a decrease in bone volume fraction of trabecular bone in the three high-altitude groups(H-4 group vs.L-4 group:[7.48±2.35]％vs.[10.40±2.93]％,P＜0.05;H-8 group vs.L-8 group:[7.17±2.68]％vs.[10.09±2.95]％,P＜0.05;H-18 group vs.L-18 group:[2.90±2.91]％vs.[8.68±4.11]％,P＜0.01),and increased trabecular separation in the three high-altitude groups(H-4 group vs.L-4 group:[0.70±0.12]mm vs.[0.60±0.06]mm,P＜0.05;H-8 group vs.L-8 group:[0.68±0.07]mm vs.[0.59±0.05]mm,P＜0.01;H-18 group vs.L-18 group:[0.80±0.09]mm vs.[0.70±0.09]mm,P＜0.05).TRAP staining showed an increase in osteoclasts in the H-4 and H-18 groups.Western blot results indicated an increase in the expression of receptor activator of nuclear factor-κB ligand(RANKL)and hypoxia inducible factor-1α(HIF-1α)in high-altitude environment,while the expression of osteoprotegerin(OPG)was inhibited.Conclusion The impact of high-altitude environment on rat femurs is characterized primarily by a reduction in trabecular bone mass and damage to bone microstructure.

Objective To explore the therapeutic effect of Cang-ai volatile oil(CAVO)on rats with myocardial hypertrophy(MH)exposed to the hypobaric hypoxic environment of the Qinghai-Tibet Plateau using 7.0-tesla(7.0T)cardiac magnetic resonance imaging(CMR).Methods A total of 50 male specific pathogen-free(SPF)Sprague-Dawley(SD)rats were randomly assigned to a low-altitude control(CON)group,hypobaric hypoxia(HH)group,myocardial hypertrophy modeling(MH)group,MH modeling plus CAVO treatment(MH+CAVO)group,and MH modeling plus benadryl hydrochloride treatment(MH+RX)group,with 10 rats in each group.Except for the CON group,the rats in all the groups were kept and fed in the standard way for 8 weeks in a high-altitude environment(at 4250 m above sea level),and then given the corresponding treatment drugs by gastric gavage.Afterwards,7.0T high field strength CMR was used to measure left ventricular(LV)function and myocardial strain.Hematoxylin-eosin(HE)staining and Masson staining were performed to observe myocardial interstitial fibrosis.Wheat germ agglutinin(WGA)staining was performed to analyze the cross-sectional area of cardiomyocytes.Transmission electron microscopy was used to observe the ultrastructural changes of the myocardium.Serum levels of cardiac troponin T(cTnT),superoxide dismutase(SOD),malondialdehyde(MDA),and glutathione peroxidase(GSH-PX)were measured by ELISA.Results Compared with those of the control group,the MH group had significantly lower left ventricular global circumferential strain(LVGCS)at(-18.85±1.67)％and left ventricular global longitudinal strain(LVGLS)at(-20.39±1.48)％(P＜0.05).However,the MH+CAVO group had significantly higher LVGCS at(-22.10±1.08)％and LVGLS at(-24.60±1.72)％compared with those of the MH group(both P＜0.05),indicating that CAVO treatment improved LV function.The MH group had a decreased level of serum glutathione peroxidase(GSH-Px)in comparison with the CON group([1173.49±27.10]U/mL vs.[300.83±47.25]U/mL,P＜0.01),a decreased SOD level in comparison with the CON group([302.27±3.65]U/mL vs.[105.96±4.03]U/mL,P＜0.01),and an increased level of serum malondialdehyde(MDA)in comparison with the CON group([57.91±1.13]μmol/L vs.[6.65±2.99]μmol/L,P＜0.01),suggesting that the antioxidant capacity of rats in the MH group was decreased.After CAVO intervention,rats in the MH+CAVO group exhibited an increase in the serum levels of SOD at(278.51±5.97)U/mL and GSH-Px at(961.82±17.56)U/mL,as well as a decrease in MDA at(17.79±1.33)μmol/L(all P＜0.05).Conclusion CAVO can effectively improve cardiac function in rats with cardiac hypertrophy exposed to high-altitude environment by modulating oxidative stress and ameliorating cardiac hypertrophy.

Objective: To investigate the incidence and influencing factors of abnormal body posture among urban primary school students in Yinchuan City, and to provide evidence for the prevention and treatment of abnormal body posture. Methods: A multi stage stratified cluster random sampling method was adopted to select 1 947 urban primary school students aged 7-12 years from 9 schools in Yinchuan City. Body Style(Model.S-8.0) instrument was used to screen abnormal body posture and questionnaire was designed to investigate related factors. Results: The comprehensive body posture score of urban primary school students in Yinchuan City was(22.07±2.87), and the detection rate of abnormal posturing was 71.29%；which varied significantly by gender, age, body mass index (BMI)( χ 2=9.84, 13.47, 6.46, P <0.05). Specially, the rate of girls (73.54%) was higher than that of boys( 69.07 %); the abnormal rate of children aged 7-8(68.24%) was lower than that of 9-10(72.17%) and 11-12(73.54%); obese children (74.91%) was higher than that of overweight (72.64%) and normal weight children(70.28%). The high and low shoulders (40.73%), pelvis forward (39.39%) and X/O legs (38.57%) were the most common indicators of abnormal posture; the composition of the overall body posture abnormalities was higher in mild (54.32%) than moderate (37.82%) and severe (7.85%).Multivariate Logistic regression analysis showed that girls( OR =1.23), being older(9-10 years old OR =1.89, 11-12 years old OR = 2.48 ), overweight ( OR =1.39) and obesity( OR =2.34), occasionally participate in physical exercise ( OR =2.96), exercise duration <30 minutes daily ( OR =2.77), video duration ≥2 h daily ( OR =2.84), almost no dairy products ( OR =1.79), almost no food Fish consumption ( OR =1.77), almost no vegetables ( OR =2.14), drinking carbonated beverages daily ( OR =2.97), and sleeping time <6 h daily ( OR =2.56) were the related factors of body posture development of urban primary school students( P <0.05). Conclusion The abnormal body posture of urban primary school students in Yinchuan City is prevalent, which is related to the timely length of physical exercise, nutrition, video screen and sleep duration, and should be paid enough attention.

Objective:To investigate the effect of magnetic resonance angiography (MRA) in evaluating the mouse model of vertebrobasilar dolichoectasia (VBD) induced by injection of elastase into cerebellomedullary cistern.Methods:Twenty-four male C57/BL6 mice were selected. The mice in the elastase group ( n=12) were injected in the cerebellomedullary cistern with 2.5 μl of phosphate buffer containing 25 mU elastase, and the mice in the saline control group ( n=12) were injected with the same volume of normal saline. MRA examination of the brains of living mice was performed 2 weeks after modeling. Successful modeling was defined as the basilar artery bending angle ≤170°, or the basilar artery bending length accounts for ≥10%, or the basilar artery deviated from the midline by more than 1 grade, or the percentage increase in artery diameter was ≥25%. Results:In the elastase group and the saline control group, 2 mice and 1 mouse did not wake up normally or died, respectively. The 11 surviving mice in the saline control group had no obvious vertebral artery and basilar artery abnormalities. The success rate of modeling in the 10 surviving mice in the elastase group was 80%, and the difference in the success rate between the two groups was statistically significant ( P<0.05). There were significant differences in mean basilar artery diameter (0.30 mm vs. 0.22 mm; P<0.05), mean basilar artery bending angle (115° vs. 170°; P<0.05), and proportion of mean basilar artery bending length (31% vs. 5%; P<0.05) of the surviving mice between the elastase group and the saline control group. Conclusion:MRA can better evaluate the mouse VBD model induced by elastase injection in the cerebellomedullary cistern.