Objective To explore the applicability of the Perceived Stress Scale(PSS) in Chinese medical students.Methods 773 medical students completed the PSS and the Depression Anxiety Stress Scale (DASS).The reliability and validity of the PSS were analyzed.Results The exploratory factor analysis showed that two factors were extracted from the scale,which could explain 53.74％ of the total variance.The confirmatory factor analysis verified that the structure of the PSS was two-dimensional (x2/df =2.863,CFI =0.943,TLI =0.924,GFI =0.951,AGFI =0.921,RMSEA =0.07).The internal consistency coefficient of the PSS,the perceived stress subscale and the perceived coping ability subscale were 0.858,0.852 and 0.750.The relationship between the PSS and the DASS was significant,which demonstrated that the PSS had a good criterion-related validity.In addition,t-test showed that girls had a higher level of the perceived stress than boys (t =-2.574,P =0.01),and students who lived in rural had a higher level of the perceived stress than students who lived in urban (t =2.788,P =0.005).Conclusion The study indicates that the PSS has a high level of the reliability and validity,and it is worthy of exploring the perceived stress in medical students.

Objective To study changes of?-glutamyltransferase(GGT)and its isoenzyme in urine and renal cortex of rats with subacute cadmium exposure.Methods Sixty healthy SD male rats were chosen and divided randomly into control group,middle dose group and high dose group,which were orally dosed daily with feed containing0,5and10mg cadmium per kg for six weeks.The activities of GGT and its isoenzyme in urine and renal cortex of the rats were determined in the3rd and6th week respectively.Re sults During the whole experimental period,the body weights and kidney to body weight ratios of control group,middle dose group and high dose group showed no significant differences.The GGT activities of middle dose group and high dose group increased significantly with the prolongation of exposure to cadmium and the increase of cumulative exposure compared with those in the control group.Unusual bands of GGT isoenzyme in the urine and renal cortex homogenate were found in the3rd week and the incidence of unusual bands of GGT isoenzyme was100percent in the6th week in the cadmium-treated rats of middle dose group and high dose group.Con clusion The GGT activities and the unusual bands of GGT isoen-zymes in the urine and renal cortex could be used as sensitive indexes to identify the renal toxic effects induced by cadmium.

Objective To evaluate left intra-ventricular diastolic blood flow patterns and fluid dynamics in pre diabetics using vector flow mapping(VFM),and to explore the value of left intra-ventricular hydromechanics characteristics assessment of intracardiac flow by VFM with more sensitive indexes.Methods Forty four patients with type 2 diabetes,twenty-eight pre-diabetes patients and thirty-three normal volunteers underwent VFM to determine the left ventricular(LV) diastolic blood flow patterns and fluid dynamics.The two-dimensional color Doppler flow images data were acquired in standerd apical fourchamber view during 3 complete cardiac cycles.These images were analyzed using a dedicated off-line workstation.At different level (mitral annulus,papillary muscl and apex level),the diastole blood flow parameters of LV including flow velocity and volume,velocity gradients (△V),pressure gradients (△P),diastole flow volume,vortex intensity ( Ⅵ),vortex area ( VA),vortex radius (VA) were derived.Thedifferences of the above parameters were compared among the three groups.The correlationship between diastolic function parameters and LV hydromechanics indexes were analyzed.Results ① Compared to normal group and pre-diabetics group,the LV diastolic function parameters E/A and e/a in diabetics group were lower( P ＜0.01),with no differences for E/e( P ＞0.05).There were no significant diffrences of these indices between diabetics group and pre-diabetics group( P ＞0.05).②)Compared to normal group,the intraventricular peak flow velocity at basal level,△V and △P in diabetics group and pre-diabetics group were lower( P ＜0.01),but there were no significant differences of these indices between diabetics group and prediabetics group( P ＞ 0.05).③Compared to normal group,the diastolic positive volume at basal level in diabetics group and pre-diabetics group was lower ( P ＜0.01 ),but there was no significant differences of these indices between diabetics group and pre-diabetics group ( P ＞ 0.05).④ Compared to the normal group,the Ⅵ in diabetics and pre-diabetics group was decreased,but there were no significant differences ofthese indices between diabetics group and pre-diabetics group( P ＞0.05).The VA and VR in diabetics and pre-diabetics group were increased,but there were no significant differences of these indices between diabetics group and pre-diabetics group ( P ＞ 0.05).⑤ There were no correlationship between diastolic function parameters and LV hydromechanics indexes.Conclusions There is the same LV diastolic blood flow patterns and fluid dynamics existed in pre-diabetics as diabetics.VFM could be used as a new methods to demonstrate the early left intra-ventricular fluid dynamics damages in pre-diabetics patients.

ObjectiveTo evaluate the myocardium damage of myocardial contrast echocardiography (MCE) and the impact on regional left ventricular mechanics by imaging and pathology techniques.Methods Eleven open-chest animal models of Beagle were employed to collect the short-axis views of mitral annular,papillary muscle and apical level of three complete cardiac cycles using gray-scale imaging at the baseline and blank irradiation 5 min later(transmitting frequency 1.7/3.4 M Hz,mechanical index 1.0).After that,5 ml of SonoVue was gotten a shot by intravenous bolus injection,the heart was exposed by ultrasonic wave for 5 min continuously,and then the same images collected were at the point-in-time irradiation immediately,20 min,40 min and 60 min later.The short-axis circumferential strain and strain rate,radial strain and strain rate were measured and calculated by EchoPAC multi-parameter workstation,meanwhile including conventional of cardiac function.All the dogs were killed after the experiments and the myocardium was harvested for HE staining and observed with transmission electron microscope for the tissue microstructure.Results①Conventional parameters of cardiac function:there was no significant difference before and after MCE in the heart rate,blood pressure,ejection fraction,left ventricular end-systolic volume and end-diastolic volume,stroke volume,cardiac output,mitral flow spectrum prior to the E/A,tissue Doppler mitral annular e/a and E/e ( P ＞0.05).During the whole process of experiment,the dogs’ vital signs were stable.②Compared the segmental circumferential strain and strain rate,radial strain and strain rate between baseline and each treatment groups,these parameters had a trend of increase in most segments,but the difference was not statistically significant in most segments (P ＞0.05).③HE staining at the light microscope demonstrated a small amount of myocardial cell infiltration of inflammatory cells near the outer membrane (21.2％),and very few part of the muscle fibers dissolved and fractured (6.1％).④The section of transmission electron microscope showed all the structures were normal except that a small amount of endothelial cells were mild swelling,some red blood cells were leaked,some myofilaments were regional dissolved,the relevance ratio were 28.6 ％,42.9 ％ and 21.4 ％ respectively,and the abnormal area was less than 10％ of the entire field of vision.ConclusionsMCE has no significant impact for the global function of heart and the regional mechanical state,and furthermore there is no serious pathological damage on the myocardium.

Objective To investigate the structure-activity relationship for 21 anthocyanins in inhibiting oxidized injury of endothelial cells,and explore the structural characteristics of anthocyanins closely related to their effects. Methods Endothelial cells were treated by ox-LDL at different concentrations of 50,100,150 or 200 ?g/ml,and MTT assay was used to determine IC50. After pre-incubated for 2 h with different concentrations ( 50,100 or 200 ?mol/L) of anthocyanins and then treated with 100 ?g/ml ox-LDL for another 24 h in endothelial cells,MTT assay was used to detect the cellular viability. After pre-treated for 2 h with different anthocyanins with 100 ?mol/L and treated with ox-LDL for another 24 h,MDA and NO level in the culture media were both measured according to the methods of assay kits. Structure-activity relationship was analyzed according to the respective cellular viability,MDA and NO level. Results Cellular viability was significantly inhibited by ox-LDL in a dose-dependent manner,and the IC50 was 100 ?g/ml. A significant correlation was observed among the effect of anthocyanins on cell viability,MDA production and NO release. The inhibitory effects of anthocyanins in ox-LDL-injured endothelial cells were positively related to the total number of hydroxyl groups and hydroxyl substitutions in B ring. 3′,4′-ortho-dihydroxyl substitution on B-ring and a 3-hydroxyl group on C-ring significantly enhanced the inhibitory effect of anthocyanins,yet methoxylation or glycosylation significantly decreased the effect. 6-hydroxylation substitution might attenuate the inhibitory effect of anthocyanins,while substitution at C5 or C5′ showed no significant influence on the effect of anthocyanins. Anthocyanin with monosaccharose substitution was much stronger than that with disaccharose substitution,while there was no significant difference between anthocyanins with glucoside and that with galacotoside substitution. Delphinidin and delphinidin-3-glucoside were respectively the most effectual anthocyanidin or anthocyanin. Conclusion 3′,4′-ortho-dihydroxyl substitution on B-ring and a 3-hydroxyl group on C-ring are the main structural requirements for anthocyanins in suppressing ox-LDL-induced injury in endothelial cells.

Objective To compare the dosimetric effects of micro-multileaf collimator (MLC)(2 mm leaf width) and conventional MLC (10 mm leaf width) on inverse intensity-modulated radiotherapy(IMRT) in intracranial stereotactic radiosurgery(SRS). Methods In view of the fact that the micro-MLC has a small open field,30 patients with intracranial tumor with a<10 cm diameter were enrolled in this study. Their inverse dynamic IMRT plans were established using conventional MLC (conventional group) and micro-MLC (micro group) with the same other conditions. The radiation doses to the target volume and the organs at risk (OAR) were compared between the two groups with t test. Results Compared with the conventional group, the micro group had a significantly better dose distribution in the target volume (P=0.019). However, there were no significant differences in D98,D95,D50,and D3between the two groups (P=0.774,0.650,0.170,0.080). The micro group had a 58.7% lower mean homogeneity index and a 20.1% higher mean conformity index than the conventional group (P=0.000). The micro group had significantly lower radiation doses to OAR than the conventional group (P=0.044). The mean Dmeanand Dmaxof the brain stem in the micro group were 10.0% and 8.2%,respectively,lower than those in the conventional group (P=0.768,0.753). The mean Dmeanand Dmax of the right eye and left eye in the micro group were 16.5%,19.3%,21.4%,and 13.4%,respectively,lower than those in the conventional group (P=0.572,0.775 and 0.734,0.630). The mean Dmaxof the left lens, right lens, left optic nerve, right optic nerve, and optic chiasm in the micro group were 50.4%, 24.1%, 38.5%, 27.8%, and 5.7%, respectively, lower than those in the conventional group (P=0.172,0.467, 0.521,0.740,0.899). The PRV100,PRV50,and PRV25of the normal tissue in the micro group were no more than those in the conventional group(P=0.839,0.832,0.972). Conclusions In inverse IMRT in intracranial SRS,micro-MLC is better than conventional MLC because it can improve CI of the target volume and reduce the radiation doses to OAR.

Abstract: Objective　To understand the epidemiological characteristics of the migratory bird population with hypertension in Hainan and to provide a basis for the health management of the migratory bird population. Methods　One hundred and eighty migratory birds with hypertension who had lived in in the Mangrove Bay community of Chengmai, Hainan for 3 months or more were selected as the study population. Demographic data, including gender, age, ethnicity, occupation, medication use, family history of hypertension, hometown living environment, Hainan living environment (presence of water area and greenbelt around the residence, type of water area and greenbelt), smoking and alcohol consumption, and height and weight were collected by questionnaire and physical examination to investigate the epidemiological characteristics of the study subjects, and unconditional dichotomous logistic regression analysis was used to identify factors affecting the reduction of blood pressure among the hypertensive migratory bird population before and after taking medication in Hainan. Results　A total of 180 study subjects were included, including 77 (42.8%) males and 103 (57.2%) females, with 78 (43.3%) subjects aged ≤65. The hypertension levels were: 87 (48.3%) had normal high blood pressure, 56 (31.1%) had grade 1 hypertension and 37 (20.6%) had grade 2 hypertension. The higher the blood pressure classification, the lower the percentage of migratory individuals whose blood pressure dropped during their stay in Hainan. Age, hypertension classification, dietary habits, living environment, body mass index (BMI), and alcohol consumption were associated with a decrease in blood pressure during Hainan among the study participants who took hypertension medication regularly. Salty diet (OR=2.778, 95%CI:1.070-7.213, P=0.036) and alcohol consumption (OR=2.686, 95%CI:1.042-6.925, P=0.041) were unfavorable factors for lower diastolic blood pressure before taking medication; overweight (OR=3.487, 95%CI:1.306-9.310, P=0.013) was an unfavorable factor in the reduction of diastolic blood pressure after taking medication. Conclusion　The blood pressure reduction is more significant in migratory individuals in migratory individuals under 65 years old, with a light diet, no alcohol consumption and normal BMI. Environmental factors, age, dietary habits and lifestyle are the main causes of blood pressure, which can provide a reference basis for the health management of the migratory birds with hypertension in Hainan.

Objective To explore the diagnostic value ofcerebrospinal fluid (CSF) lactic acid (LA) level in bacterial meningitis after craniotomy for cerebral hemorrhage in adults.Methods The clinical data of 162 patients with cerebral hemorrhage,admitted to and accepted craniotomy in our hospital from April 2013 to April 2018,were retrospectively collected;patients were divided into infected group (n=75) and non-infected group (n=87) according to whether postoperative bacterial meningitis occurred;univariate analysis was used to compare the differences of CSF-LA concentration and other indicators of CSF between patients of the two groups;multivariate Logistic regression analysis was used to screen the independent factors affecting the occurrence of postoperative bacterial meningitis;receiver operating characteristic (ROC) curve was used to analyze the predictive values of CSF-LA and other indicators in postoperative bacterial meningitis.Furthermore,17 patients with positive bacterial CSF were divided into Gram-positive (G+) bacteria group (n=9) and Gram-negative (G-) bacteria group (n=8);the predictive values of CSF-LA and other indicators for postoperative meningitis of G-bacteria patients were analyzed in the same way.Results (1) The CSF-LA concentration in infected group ([6.3±2.8] mmol/L) was significantly increased as compared with that in non-infected group ([3.3±1.6] mmol/L,P＜0.05);the results of multivariate Logistic regression analysis showed that CSF-LA was an independent influencing factor for postoperative bacterial meningitis (odd ratio=l.547,95％ confidence interval:1.029-2.326,P=0.036);ROC curve results revealed that the area under the curve of CSF-LA concentration in the diagnosis of bacterial meningitis after craniotomy was 0.854 (95％ confidence interval:0.790-0.904),and the optimal cut-off value was 4.61 mmol/L,with sensitivity of 69.3％,specificity of 92.0％,positive predictive value of 88.1％ and negative predictive value of 77.7％.(2) The CSF-LA concentration in G-bacteria group ([9.9±2.9] mmol/L) was significantly increased as compared with that in G+ bacteria group ([5.2±3.1] mmoi/L,P＜ 0.05);ROC curve results revealed that,in patients with positive bacterial CSF,the area under the curve of CSF-LA concentration in diagnosis of meningitis with G-bacteria after craniotomy was 0.861 (95％ confidence interval:0.610-0.978),and the optimal cut-off value was 7.20 mmol/L with sensitivity of 87.5％,specificity of 88.9％,positive predictive value of 87.5％,and negative predictive value of 88.9％.Conclusion Detection for concentration of CSF-LA can help predicting bacterial meningitis afier craniotomy for cerebral hemorrhage and identify G+ and G-bacteria meningitis.

Objective:To investigate the current situation and influencing factors of humanistic care needs of family members of pregnant women in maternal intensive care unit, and to explore the relationship between humanistic care needs of family members of pregnant women in maternal intensive care unit, relocation stress level and perceived social support ability, so as to provide a basis for clinical nursing staff to implement targeted humanistic care for family members of pregnant women in maternal intensive care unit.Methods:From July to December 2022, 267 family members of pregnant women who were observed in the Maternal Intensive Care Unit of Maternity Hospital Affiliated to Nanjing Medical University/Nanjing Maternal and Child Health Hospital were selected as the research objects by the convenient sampling method. The general information questionnaire, Humanistic Care Needs Scale for Family Members of Pregnant Women in the Obstetric Intensive Care Unit, Family Relocation Stress Scale for Intensive Care Unit Patients and Perceived Social Support Scale were used to carry out a cross sectional investigation.Results:The scores of humanistic care needs, relocation stress scale and perceived social support scale were (175.32 ± 16.04), (35.12 ± 8.11), (57.30 ± 15.43) points, respectively. The length of maternal intensive care unit stay ( B=1.301, P<0.05), the family′s role changed for the first time ( B=2.328, P<0.05), the delivery mode doesn′t match the family′s expectations ( B=-2.407, P<0.05), maternal admission to maternal intensive care unit due to childbirth complications ( B=3.228, P<0.05), relocation stress level of intensive care unit patients′ family members ( B=0.891, P<0.05), and family members′ perceived social support ability ( B=0.461, P<0.05) were the influencing factors of humanistic care needs of maternal family members in maternal intensive care unit factors, which explained 83.2% of the total variation. Conclusions:The humanistic care needs of family members of pregnant women in maternal intensive care unit are at a high level. Medical staff should pay more attention to the family members of pregnant women who stay in maternal intensive care unit for a long time, undergo role change for the first time, have unexpected delivery mode and stay in maternal intensive care unit due to childbirth complications, so as to provide them with more comprehensive humanistic care and establish multiple support system, in order to improve the level of humanistic care for the family members of maternal intensive care unit.

Objective To investigate the efficacy and safety of camrelizumab monoclonal antibody combined with molecular-targeted therapy in elderly patients with unresectable or advanced hepatocellular carcinoma(HCC).Methods A retrospective analysis was performed for the patients with unresectable/advanced HCC who attended six hospitals from January 1,2019 to March 31,2021,and all patients received camrelizumab monoclonal antibody treatment,among whom 84.8%also received targeted therapy.According to the age of the patients,they were divided into elderly group(≥65 years)and non-elderly group(＜65 years).The two groups were assessed in terms of overall survival(OS),progression-free survival(PFS),objective response rate(ORR),disease control rate(DCR),and immune-related adverse events(irAE).The chi-square test or the Fisher's exact test was used for comparison of categorical data between groups;the independent samples t-test was used for comparison of normally distributed continuous data,and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups.The Kaplan-Meier method was used for survival analysis,and the log-rank test was used for comparison of survival curves.Univariate and multivariate Cox proportional hazards regression analyses were used to determine the independent influencing factors for PFS and DCR at 6 months.Results A total of 99 HCC patients were enrolled,with 27 in the elderly group and 72 in the non-elderly group.The elderly group had an OS rate of 67.8%,an ORR of 44.4%,and a DCR of 74.1%at 12 months and a median PFS of 6.4(95%confidence interval[CI]:3.0-12.4)months,with no significant differences compared with the non-elderly group(all P＞0.05).The median OS was unavailable for the elderly group,while the non-elderly group had an OS of 18.9(95%CI:13.0-24.8)months;there was no significant difference between the two groups(P=0.485).The univariate and multivariate Cox regression analyses showed that major vascular invasion(MVI)was an independent risk factor for PFS(hazard ratio[HR]=2.603,95%CI:1.136-5.964,P=0.024)and DCR(HR=3.963,95%CI:1.671-9.397,P=0.002)at 6 months,while age,sex,etiology of HBV infection,presence of extrahepatic metastasis,Child-Pugh class B,and alpha-fetoprotein＞400 ng/mL were not associated with PFS or DCR at 6 months.For the elderly group,the incidence rates of any irAE and grade 3/4 irAE were 51.9%and 25.9%,respectively,with no significant differences compared with the non-elderly group(P＞0.05),and skin disease was the most common irAE in both groups(39.4%).Conclusion Camrelizumab monoclonal antibody combined with molecular-targeted therapy has similar efficacy and safety in patients with unresectable/advanced HCC aged≥65 years and those aged＜65 years.MVI is associated with suboptimal response to immunotherapy and poor prognosis.