Objective:To understand the contract renewal willingness and its influencing factors among rural order-oriented medical students in Shaanxi Province. M ethods This study employed an explanatory sequential mixed methods design to examine contract renewal patterns among rural order-oriented medical graduates. From February to July 2024, a questionnaire survey was conducted among rural order-oriented medical students who graduated from 2015 to 2023 in Shaanxi Province. The participants were first stratified into three strata based on their year of graduation and stage of service, and one-third of each stratum was randomly selected as the research subjects. Univariate and multivariate analysis methods were used to explore the influencing factors of their willingness to renew their service in rural areas. Secondly, qualitative research methods were employed to conduct thematic interviews with 36 targeted medical students on the influencing factors of their willingness to renew their service. Results:A total of 513 valid questionnaires were collected during the quantitative research phase, including 224 males and 289 females. Of these, 14 were from the 2015-2017 cohort, 247 from the 2018-2020 cohort, and 252 from the 2021-2023 cohort. The results showed that only 30.4%(156/513) of the orientation medical students were willing to practice in primary care after the period of service. Univariate analysis showed that there were six factors related to the willingness to renew the contract, the consistency of the source and implementation of the contract, the completion of the standardized training of residents, the satisfaction with primary work, professional identity, the ability of primary diagnosis and treatment, and the training system and the suitability of primary work. Multivariate analysis showed that the willingness to renew the contract was significantly higher in the students who had the same place of origin and the place of performance( OR=1.7, 95% CI: 1.1-2.6, P=0.022). The willingness to renew the contract was significantly higher among students who participated in the standardized residency training than those who completed the training( OR=2.0, 95% CI: 1.3-3.0, P=0.003), and students with a better fit between the training system and working in primary care were more likely to renew their contract( OR=4.1, 95% CI: 2.8-6.0, P<0.001). Four themes were extracted from the interview: subjective factors, objective environment, policy factors and other factors. Conclusions:The study shows that improving the consistency of the source of students and the implementation of the contract, strengthening the standardized training of residents, and optimizing the adaptation of the training system to the primary work are the key measures to improve the willingness of directional medical students to renew their contract at the primary level.

In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics.Similarities and variations of components present significant analytical challenges.A two-dimensional(2D)liquid chromatography-mass spectrometry(LC-MS)method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium(CMS).A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated.For efficient and high-accuracy screening of CMS,a targeted method based on a self-constructed high resolution(HR)mass spectrum database of CMS components was established.The database was built based on the commercial MassHunter Personal Compound Database and Library(PCDL)software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening.On this basis,the unknown peaks in the CMS chromatograms were deduced and assigned.The molecular formula,group composition,and origins of a total of 99 compounds,of which the combined area percentage accounted for more than 95％of CMS components,were deduced by this 2D-LC-MS method combined with the MassHunter PCDL.This profiling method was highly efficient and could distinguish hundreds of components within 3 h,providing reliable results for quality control of this kind of complex drugs.

In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics. Similarities and variations of components present significant analytical challenges. A two-dimensional (2D) liquid chromatography-mass spectrometr (LC-MS) method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium (CMS). A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated. For efficient and high-accuracy screening of CMS, a targeted method based on a self-constructed high resolution (HR) mass spectrum database of CMS components was established. The database was built based on the commercial MassHunter Personal Compound Database and Library (PCDL) software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening. On this basis, the unknown peaks in the CMS chromatograms were deduced and assigned. The molecular formula, group composition, and origins of a total of 99 compounds, of which the combined area percentage accounted for more than 95% of CMS components, were deduced by this 2D-LC-MS method combined with the MassHunter PCDL. This profiling method was highly efficient and could distinguish hundreds of components within 3 h, providing reliable results for quality control of this kind of complex drugs.

Objective To investigate the combined effect of coronary artery calcification score(CACS)progression and sleep structure on major adverse cardiovascular events(MACE).Methods Data from the Multi-Ethnic Study of Atherosclerosis(MESA)were used to analyze participants and assess the interaction impact of CACS progression and different sleep stages on predicting MACE.Polysomnography(PSG)record provide an objective measure of sleep structure.Results The results of this study confirmed the dose-response relationship between CACS progression and MACE.ΔCACS 10-99 hazard ratio(HR)was 6.913(P＜0.001),ΔC ACS 100-199 HR was 22.098(P＜0.001),ΔCACS＞200 HR was 20.608(P＜0.001),reinforcing the notion that the rate of CACS development significantly affects cardiovascular risk.In addition,the study found that participants who showed lower rapid eye movement(REM)sleep and progression of CACS had the greatest risk of developing MACE,while participants who showed higher REM sleep but no progression of CACS had the lowest risk of developing MACE(P＜0.001).Conclusion Decreased REM sleep increases the risk of MACE in CACS patients,and maintaining adequate REM sleep may reduce this risk,emphasizing the protective effect of REM sleep on cardiovascular disease.

Objective To investigate the combined effect of coronary artery calcification score(CACS)progression and sleep structure on major adverse cardiovascular events(MACE).Methods Data from the Multi-Ethnic Study of Atherosclerosis(MESA)were used to analyze participants and assess the interaction impact of CACS progression and different sleep stages on predicting MACE.Polysomnography(PSG)record provide an objective measure of sleep structure.Results The results of this study confirmed the dose-response relationship between CACS progression and MACE.ΔCACS 10-99 hazard ratio(HR)was 6.913(P＜0.001),ΔC ACS 100-199 HR was 22.098(P＜0.001),ΔCACS＞200 HR was 20.608(P＜0.001),reinforcing the notion that the rate of CACS development significantly affects cardiovascular risk.In addition,the study found that participants who showed lower rapid eye movement(REM)sleep and progression of CACS had the greatest risk of developing MACE,while participants who showed higher REM sleep but no progression of CACS had the lowest risk of developing MACE(P＜0.001).Conclusion Decreased REM sleep increases the risk of MACE in CACS patients,and maintaining adequate REM sleep may reduce this risk,emphasizing the protective effect of REM sleep on cardiovascular disease.

Objective:To understand the contract renewal willingness and its influencing factors among rural order-oriented medical students in Shaanxi Province. M ethods This study employed an explanatory sequential mixed methods design to examine contract renewal patterns among rural order-oriented medical graduates. From February to July 2024, a questionnaire survey was conducted among rural order-oriented medical students who graduated from 2015 to 2023 in Shaanxi Province. The participants were first stratified into three strata based on their year of graduation and stage of service, and one-third of each stratum was randomly selected as the research subjects. Univariate and multivariate analysis methods were used to explore the influencing factors of their willingness to renew their service in rural areas. Secondly, qualitative research methods were employed to conduct thematic interviews with 36 targeted medical students on the influencing factors of their willingness to renew their service. Results:A total of 513 valid questionnaires were collected during the quantitative research phase, including 224 males and 289 females. Of these, 14 were from the 2015-2017 cohort, 247 from the 2018-2020 cohort, and 252 from the 2021-2023 cohort. The results showed that only 30.4%(156/513) of the orientation medical students were willing to practice in primary care after the period of service. Univariate analysis showed that there were six factors related to the willingness to renew the contract, the consistency of the source and implementation of the contract, the completion of the standardized training of residents, the satisfaction with primary work, professional identity, the ability of primary diagnosis and treatment, and the training system and the suitability of primary work. Multivariate analysis showed that the willingness to renew the contract was significantly higher in the students who had the same place of origin and the place of performance( OR=1.7, 95% CI: 1.1-2.6, P=0.022). The willingness to renew the contract was significantly higher among students who participated in the standardized residency training than those who completed the training( OR=2.0, 95% CI: 1.3-3.0, P=0.003), and students with a better fit between the training system and working in primary care were more likely to renew their contract( OR=4.1, 95% CI: 2.8-6.0, P<0.001). Four themes were extracted from the interview: subjective factors, objective environment, policy factors and other factors. Conclusions:The study shows that improving the consistency of the source of students and the implementation of the contract, strengthening the standardized training of residents, and optimizing the adaptation of the training system to the primary work are the key measures to improve the willingness of directional medical students to renew their contract at the primary level.

Objective:To construct a porcine model of ischemia with non-obstructive coronary artery (INOCA) and explore the diagnostic value of a one-stop noninvasive method including CT myocardial perfusion imaging (CT-MPI) and coronary CT angiography (CCTA).Methods:Twelve swines were divided into the experimental group (9) and the normal group (3). Coronary microvascular dysfunction (CMD) porcine model was constructed in the experimental group by inducing diabetes mellitus, chronic kidney disease, and hypercholesterolemia. Invasive coronary angiography (ICA) and functional examination were performed on all 7+3 trial swines to clarify the INOCA diagnosis after completion of the modeling. Then, CT-MPI and CCTA were performed on all individuals to explore the CT-MPI and CCTA characteristics of INOCA porcine models. CT-MPI parameters, including myocardial blood flow (MBF), and myocardial blood volume (MBV) in rest and stress conditions, and CCTA parameters, including severity of stenosis and CAD-RADS, were analyzed.Results:ICA and functional tests showed that all swines in the experimental group met the diagnostic criteria for INOCA, which meant that INOCA porcine model was constructed successfully. CCTA results confirmed that there was no obstructive coronary stenosis in all 10 swines which were examined, which was consistent with ICA findings. CT-MPI results demonstrated that the mean MBF values, as well as the mean MBV values, in the rest and stress condition of each swines in the experimental group were lower than those of the control group. In contrast to the control group, the mean MBF and MBV values of swines in the experimental group in stress condition were generally lower than those in resting condition.Conclusions:In this study, a porcine model of CMD is successfully constructed by inducing hypercholesterolemia+diabetes mellitus+chronic kidney disease. ICA and invasive functional tests show that this CMD model meet the diagnostic criteria for INOCA. It has been confirmed that one-stop CT multimodality examination including CT-MPI and CCTA can be used for the diagnosis of INOCA as a noninvasive diagnostic method.

Objective:To explore the difference of the vessel and plaque characteristics, myocardial perfusion and cardiac function between patients with ischemia with non-obstructive coronary artery disease (INOCA) and obstructive coronary artery disease (CAD).Methods:From July 2021 to June 2022, 101 patients with angina were referred to dynamic computed tomography myocardial perfusion (CTP) and coronary computed tomography angiography (CCTA) and retrospectively included in our hospital. Based on the results of CTP and CCTA, patients were divided into INOCA (27 cases), moderate obstructive CAD (26 cases) and severe obstructive CAD (48 cases). The anatomical coronary artery stenosis, plaque characteristics and myocardial perfusion features of all patients were analyzed. Furthermore, left ventricular global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) were obtained on full-phase reconstruction CCTA image by using Medis Suite 3.2 postprocessing software. Multigroup analysis used one way ANOVA or Kruskal Wallis H test. Results:Patients with INOCA were younger than patients with moderate and severe obstructive CAD ( P<0.001). INOCA patients (7.4%, 2/27) had lower rate of positive remodeling than both moderate (57.7%, 15/26, P<0.001) and severe obstructive CAD patients (33.3%, 16/48, P=0.017). The percentage of ischemic myocardium volume in patients with INOCA were similar with those in patients with severe CAD (all P>0.05), but significantly higher than those in patients with moderate CAD (all P<0.05). No significant difference in terms of GLS was detected between patients with INOCA [-17.4% (-21.6%, -11.6%)] and severe CAD [-17.6% (-21.9%, -14.8%), P=0.536], however, patients both with INOCA and severe CAD also had higher GLS than patients with moderate obstructive CAD [-22.3% (-29.8%, -19.0%), all P<0.05]. Conclusions:Based on"one-stop-shop"CTP combined with CCTA imaging, early cardiac functional changes including abnormal myocardial perfusion and myocardial strain in INOCA patients were similar to those in patients with severe obstructive CAD and more severe than those in patients with moderate obstructive CAD.

OBJECTIVES: This study evaluated the association between obesity and glaucoma in middle-aged and older people. A population-based retrospective cohort study was conducted using data from the China Health and Retirement Longitudinal Study. METHODS: Glaucoma was assessed via self-reports. Multivariate logistic regression analysis and a Cox proportional hazards model were used to assess the relationship between obesity and glaucoma risk. RESULTS: Older males living in urban areas who were single, smokers, and non-drinkers were found to have a significantly higher incidence of glaucoma (all p<0.05). Diabetes, hypertension, and kidney disease were also associated with higher glaucoma risk, while dyslipidemia was associated with lower risk (all p<0.05). After the model was adjusted for demographic, socioeconomic, and health-related variables, obesity was significantly associated with a 10.2% decrease in glaucoma risk according to the Cox proportional hazards model (hazard ratio, 0.90; 95% confidence interval [CI], 0.83 to 0.97) and an 11.8% risk reduction in the multivariate logistic regression analysis (odds ratio, 0.88; 95% CI, 0.80 to 0.97). A further subgroup analysis showed that obesity was associated with a reduced risk of glaucoma in people living in rural areas, in smokers, and in those with kidney disease (all p<0.05). Obesity also reduced glaucoma risk in people with diabetes, hypertension, or dyslipidemia more than in healthy controls (all p<0.05). CONCLUSIONS This cohort study suggests that obesity was associated with a reduced risk of glaucoma, especially in rural residents, smokers, and people with kidney disease. Obesity exerted a stronger protective effect in people with diabetes, hypertension, or dyslipidemia than in healthy people.

Objective:To investigate the differences of white matter diffusion properties between vulnerable and resistant individuals to continuous attention after sleep deprivation.Methods:According to the psychomotor vigilance test performance before and after sleep deprivation, the participants were divided into the vulnerable group( n=24) and resistant group( n=25). All participants underwent diffusion tensor imaging (DTI) scans.Tract based spatial statistics(TBSS) was used to compare fractional anisotropy(FA), mean diffusivity(MD), axial diffusivity(AD), radial diffusivity(RD) maps between the two groups.Spearman correlation analysis was conducted by SPSS 24.0 to investigate the relationships between the altered DTI metrics and PVT task performance. Results:(1) Compared with resistant group, FA value of vulnerable group decreased in the body of corpus callosum(x, y, z=-8, 9, 25, t=-7.855), right superior longitudinal fasciculus(x, y, z=-39, -7, 26, t=-6.252), bilateral anterior limb of internal capsule(x, y, z=-13, 8, 13, t=-5.235; x, y, z=12, 8, 3, t=-5.024) and right posterior thalamic radiation(x, y, z=-26, -56, 17, t=-5.469)(TFCE corrected, P<0.05, cluster size≥50 voxel). (2) Compared with resistant group, MD value of vulnerable group increased in the body of corpus callosum(x, y, z=-3, -6, 26, t=7.613), right superior longitudinal fasciculus(x, y, z=-31, -19, 38, t=5.314), bilateral anterior limb of internal capsule(x, y, z=-16, 7, 8, t=6.898; x, y, z=15, 5, 7, t=6.652), splenium of corpus callosum(x, y, z=27, -53, 17, t=6.541), and AD value increased in the right superior longitudinal fasciculus(x, y, z=-33, -19, 39, t=4.892), splenium of corpus callosum(x, y, z=-22, -49, 21, t=5.450), genu of corpus callosum(x, y, z=4, 26, 0, t=4.332), as well as RD value increased in the right superior corona radiata(x, y, z=-17, 1, 33, t=7.558), body of corpus callosum(x, y, z=4, -8, 26, t=6.699), right anterior limb of internal capsule(x, y, z=-12, 7, 3, t=5.212) (TFCE corrected, P<0.05, cluster size≥50 voxel). (3) Correlational analysis revealed that the negative correlations were found between PVT task performance and the FA value in the right superior longitudinal fasciculus( r=-0.492, P<0.001), right anterior limb of internal capsule( r=-0.510, P<0.001), right posterior thalamic radiation( r=-0.502, P<0.001) and body of corpus callosum( r=-0.464, P<0.001). The positive correlations were found between PVT task performance and the MD value in the body of corpus callosum( r=0.500, P<0.001), right superior longitudinal fasciculus( r=0.499, P<0.001), splenium of corpus callosum( r=0.462, P<0.001), right anterior limb of internal capsule( r=0.471, P<0.001), and AD value in right superior longitudinal fasciculus( r=0.643, P<0.001), as well as RD value in right superior corona radiate( r=0.498, P<0.001) (Bonferroni corrected, P<0.003). Conclusion:Differences in the microstructural characteristics of white matter fiber tracts in specific brain regions may constitute the potential neuropathological basis for the phenotypes of vulnerable and resistant individuals to continuous attention after sleep deprivation.