Objective:To explore the effects of canagliflozin on cardiac function and its regulation of ferroptosis in rats with heart failure with preserved ejection fraction (HFpEF).Methods:Thirty-two 7-week-old Dahl salt-sensitive rats were selected and randomly divided into four groups: the control group (fed with low-salt diet), the HFpEF group (fed with high-salt diet), the canagliflozin 20 group (fed with high-salt diet and 20 mg·kg -1·d -1 canagliflozin), and the canagliflozin 30 group (fed with high-salt diet and 30 mg·kg -1·day -1 canagliflozin). Body weight and blood pressure of the rats in each group were monitored. Metabolic cage tests were conducted at the10 th week of the experiment, and echocardiography was performed at the 12 th week, after which the rats were killed. Blood and left ventricular samples were collected. HE staining, Masson staining, Prussian blue iron staining, and reactive oxygen species staining were performed to observe the cardiomyocyte size and shape, degree of interstitial fibrosis, iron staining, reactive oxygen species production under optical microscope. The ultrastructure of cardiomyocytes was observed under electron microscope. Western blotting and real-time fluorescent quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to detect the expression levels of proteins and mRNA related to ferroptosis in left ventricular myocardial tissue of rats in each group. Results:After 1 week of adaptive feeding, all rats survived. Metabolic cage results showed that compared with control group, rats in the HFpEF group, canagliflozin 20 group and canagliflozin 30 group had more food intake, water intake and urine output, and lower body weight (all P<0.05). These changes were more pronounced in canagliflozin 20 group and canagliflozin 30 group than in HFPEF group, and only the body weight at the 12 th week showed a statistically significant difference between canagliflozin 20 group and canagliflozin 30 group ( P<0.05). The blood pressure of 6 th week and 12 th week, heart weight and left ventricular corrected mass of 12 th week of rats in HFpEF group were higher than those in control group, canagliflozin 20 group and canagliflozin 30 group, while the ratio of early mitral valve peak velocity to late mitral valve peak velocity of 12 th week was lower (all P<0.05). HE and Masson staining showed that compared to control group, the myocardial fibers in the left ventricular myocardial tissue of rats in HFpEF group were disordered, with larger cell diameter ((0.032±0.004) mm vs. (0.023±0.003) mm, P<0.05), irregular shape, obvious proliferation of interstitial collagen fibers, and higher collagen volume fraction (0.168±0.028 vs. 0.118±0.013, P<0.05). Compared with HFpEF group, rats in the canagliflozin 20 group and canagliflozin 30 had more orderly arranged myocardial fibers, more regular cardiomyocyte shape, smaller cell diameter, and lower collagen volume fraction ( P<0.05). It was observed under electron microscopy that, compared to control group, most of the striated muscles in myocardial tissue of HFpEF group were broken, and the Z line and M line could not be clearly distinguished, some changes such as mitochondrial swelling, membrane thickening, cristae reduction or even disappearance occurred. In the canagliflozin 20 group and canagliflozin 30 group, the arrangement of striated muscles in the myocardial tissue of rats tended to be more regular, and the morphological changes of mitochondria were milder. Prussian blue iron staining results showed that the iron content in myocardial tissue of rats in HFpEF group was higher than that in control group, canagliflozin 20 group and canagliflozin 30 group. Reactive oxygen species staining results showed that the reactive oxygen species content in the myocardial tissue of rats in HFpEF group was higher than that of control group, canagliflozin 20 group and canagliflozin 30 group. Biochemical analysis of myocardial tissue showed that Fe 2+ and malondialdehyde content in myocardial tissue of rats in HFpEF group were higher than those in control group, canagliflozin 20 group and canagliflozin 30 group, while glutathione content was lower (all P<0.05). Western blot and RT-qPCR detection results showed that compared to control group, rats in HFpEF group had higher expression levels of transferrin receptor 1 (protein relative expression level: 1.37±0.16 vs. 0.31±0.12), acyl-CoA synthetase long-chain family member 4 (protein relative expression level: 1.31±0.15 vs. 0.63±0.09) protein and mRNA, and lower expression levels of ferritin heavy chain 1 (protein relative expression level: 0.45±0.08 vs. 1.41±0.15) protein and mRNA (all P<0.05). There was no statistically significant difference in these indicators between canagliflozin 20 group and the canagliflozin 30 group (all P>0.05). There was no significant difference in levels of glutathione peroxidase 4 protein and mRNA expression in myocardial tissue of rats in four groups( P>0.05). Conclusion:Canagliflozin improves cardiac function in HFpEF rats by regulating the ferroptosis mechanism.

Objective:To investigate the application of three-dimensional image reconstruction combined with problem-based learning (PBL) in the teaching of physicians receiving continuing education in thoracic surgery.Methods:A total of 68 physicians who received continuing education in Department of Thoracic Surgery in our hospital were selected as research subjects, and they were divided into control group and observation group using a random number table, with 34 physicians in each group. The physicians in the control group received traditional teaching, while those in the observation group received three-dimensional image reconstruction combined with PBL teaching. A questionnaire survey, theoretical assessment, and assessment of practical skills were performed to evaluate the effect of teaching. SPSS 22.0 was used to perform the t-test. Results:Compared with the control group, the observation group had significantly higher degrees of satisfaction with each item of the questionnaire survey ( P<0.05). Compared with the control group, the observation group had significantly higher scores of theoretical assessment [(94.07±6.03) vs. (86.34±5.46), P<0.001] and the assessment of practical skills [(95.20±5.48) vs. (84.71±6.14), P<0.001]. Conclusion:The application of three-dimensional image reconstruction combined with PBL teaching can help to improve the comprehensive ability of physicians receiving continuing education.

Objective: To explore the predictive value of CHADS2and CHA2DS2-VASc scores for late recurrence after catheter ablation( CA) of atrial fibrillation. Methods: 92 patients with atrial fibrillation of CA who hospitalized in the Second Affiliated Hospital of Anhui Medical University for the first time from July 2018 to December2020 were collected. Results: From the 3rd postoperative month to the 6th postoperative month,atrial fibrillation outpatients should follow-up each month. 92 patients were collected,of which 3 were missing during follow-up,89were followed up,and late postoperative recurrence ratio was 24%. Compared with patients without recurrence,recurrent patients were significantly higher in age,smoking( 30%),diabetes mellitus( 38%),heart failure( 29%),platelet count,left atrial diameter( LA),CHADS2,and CHA2DS2-VASc scores; furthermore Logistic regression analyzed variance factors that were not included in the score: CHADS2( OR = 13. 473,95% CI: 3. 804-47. 713),LA( OR = 1. 193,95% CI: 1. 049-1. 356)( P<0. 05); CHA2DS2-VASc( OR = 5. 363,95% CI: 2. 822-10. 193),LA( OR = 1. 245,95% CI: 1. 087-1. 426)( P<0. 05). ROC curves predicted the values of two sets of scores for late recurrence after CA,AUC( CHADS2) = 0. 8578( 95% CI: 0. 7618-0. 9539),AUC( CHA2DS2-VASc) = 0. 8848( 95% CI: 0. 7985-0. 9711). Conclusion LA,CHADS2and CHA2DS2-VASc scores are independent risk factors for late recurrence after CA of atrial fibrillation,and CHA2DS2-VASc scores have better predictive value.

Objective To analyze the biomechanical characteristics of 3 different posterior internal fixation methods for treating thoracolumbar burst fracture by three-dimensional finite element (FE) method. Methods The FE fixation models of normal thoracolumbar, short-segment posterior fixation (SSPF), short-segment posterior fixation with intermediate screws at fractured level (SSPFI) and long-segment posterior fixation (LSPF) were established, respectively. The biomechanical characteristics of L1 centrum and the adjacent intervertebral disc under 6 kinds of motion states (spinal flexion, extension, lateral bending and axial rotation), in normal thoracolumbar model and 3 fixation models were compared by FE analysis. Results L1 centrum equivalent stress distributions in normal thoracolumbar model, SSPF model, SSPFI model, LSPF model were 31.63, 13.41, 110.35, 13.17 MPa, respectively. The maximum equivalent stress of adjacent intervertebral disc in normal thoracolumbar model was 3.84 MPa, which was located in L1-2 intervertebral disc; the maximum equivalent stress of adjacent intervertebral disc in 3 fixation models was 0.41, 0.36, 0.40 MPa, respectively, which was all located in T12-L1 intervertebral disc. Conclusions Fixation in short segment of the fractured vertebrae could lead to an increase of stress in the centrum. The stress of the adjacent intervertebral disc in 3 fixation models was smaller than that in normal spinal model.

Objective To study the influence of optimization of parenteral nutrition strategy on the head circumference and brain volume in very low birth weight infants.Method Very low birth weight infants admitted to NICU of University of Hong Kong-Shen Zhen Hospital from January 2014 to June 2016 were assigned to optimized group and conventional group according to early nutritional strategies.Early parenteral nutrition intakes were increased in infants assigned to optimizated group.Nutrition intakes and parenteral nutrition related complications within 28 days after birth were compared between groups.All participants underwent brain MRI at corrected gestational age (CGA) 36 weeks.Head circumference and brain volume measured by MRI were also compared between groups.Result A total of 40 preterm infants were recruited,with 20 infants in each group.There were no significant differences in the gestational age,birth weight,brain injury and intrauterine growth retardation rate between the two groups (P ＞ 0.05).The average daily total calories and protein intake of optimization group during the first 4 weeks were significantly higher than those of conventional group,respectively [(101.5 ± 3.1) kcal/ (kg · d) vs.(96.1 ± 3.2)kcal/(kg·d),(3.07±0.16) g/(kg·d) vs.(2.90±0.11) g/(kg· d),P＜ 0.05].Theaverage daily calorie intake and protein intake of optimization group was increased by 4.7％ and 5.5％,compared with those of conventional group.Compared with the conventional group,head circumference and total brain volume of optimized group at CGA 36 weeks was improved by 3.3％ and 4.1％,and the differences were both statistically significant (P ＜ 0.05).Cerebral cortex gray matter volume of optimized group was significantly higher than that of conventional group [(102.4 ± 4.9) ml vs.(96.4 ± 4.6) ml,P ＜ 0.05].There was no significant difference in brain white matter,deep gray matter and cerebrospinal fluid volume between the two groups (P ＞ 0.05).Conclusion The optimization of parenteral nutrition within the framework of active nutrition strategy of preterm infants can further improve the early nutritional intake of preterm infants,leading to the increase of the head circumference and the gray matter volume of the cerebral cortex.

Objective To analyze effects of target-oriented liquid therapy on postoperative complications in elderly hypertensive patients with radical gastrectomy.Methods 156 elderly patients with hypertension who underwent radical gastrectomy in our hospital from January 2014 to December 2015 were divided into the conventional group and the target group according to a random number table.Routine infusion was given to the patients in the conventional group,while the patients in the target group were treated with intraoperative target oriented liquid therapy.Intraoperative liquid intake and output volume,hospital stay,vasoactive drug use rate and the incidence of complications within 1 month after surgery were compared between the two groups.Results Target group versus conventional group showed that the colloid volume was(832.3 ± 216.6) ml vs.(1 031.3±245.8) ml,the amount of crystals was(1 157.6±149.2) ml vs.(1 559.8±201.4) ml,the total fluid replenishment was(1 940.2 ± 328.9) ml vs.(2 650.0 ± 276.6) ml,the hospitalization time was (9.8 ± 1.1) d and (12.5 ± 2.0) d (t =-5.607,-13.771,-18.021 and-10.447,respectively,all P=0.000).The use rate of vasoactive drugs was higher in the conventional group[69.2％ (54/ 78)] than in the target group [29.5 ％ (23 / 78)] (x2 =24.645,P =0.000).The complications within 1 months after surgery was higher in the conventional group[12.8％ (10/78)]than in the target group[3.8％ (3/78)] (x2=4.112,P=0.043).Conclusions Target-oriented liquid therapy can improve the prognosis of elderly patients receiving radical gastrectomy,reduce the incidence of postoperative complications and promote the early rehabilitation.

Objective To establish a type of porcine model for controlled Cardiac Deceased Donor.Method Using the wuzhishan miniature pig 2 ～ 4 months of age.After intravenous general anesthesia and respiratory,after open heart surgery to produce myocardial infarction model,to heartbeat stop completely,stop breathing machine and drug support,so we established a miniature pig cardiac death donor model.Record during the heart rate,systolic pressure,diastolic blood pressure,central venous blood pressure,blood oxygen saturation and regularly take on blood gas analysis.Before cardiac arrest,monitoring hemodynamic,blood gas analysis,and the time of death before the circulatory failure.After cardiac arrest respectively 0 min,15 min and 30 min,perfusion for donor organs (liver/kidney),get the pig's liver/kidney in the different time of the groups,observed the pathological changes of liver/kidney tissues by HE staining.Result The heartbeat stop completely occurs 7 ± 0.17 minutes after left descending coronary artery ligation and cease of assisted respiration in the different groups,systolic pressure,diastolic blood pressure,central venous pressure,blood oxygen saturation,CO2 partial pressure changed significantly;Immediately after cardiac arrest for compared group (0 min),schemia-reperfusion that group of 15 min after cardiac arrest injury is obvious,ischemia-reperfusion that group of 30 min after cardiac arrest injury is further.Conclusion Miniature pig donor model obtained in this method respiratory cycle failure stability,can be controlled,no adverse drug reactions,the organ ischemia-reperfusion injury caused by repetitive is better.

The distribution and prevalence of low pathogenic avian influenza virus in major live poultry wholesale markets around the Dongting Lake region ,China were investigated in our study to propose prevention and control measures on low pathogenic avian flu in the area of live poultry wholesale market .The samples were injected to SPF chicken embryos by allanto-ic cavity ,and then the allantoic fluid were harvested and used for hemagglutination (HA) .If it was positive by HA ,subtypes of the virus would be determined by hemagglutination inhibition (HI) and RT-PCT .We isolated 627 low pathogenic avian in-fluenza viruses in major live poultry wholesale market around Dongting Lake region systematically in winter and spring during 2009-2011 ,and the total separation rate was 22 .2% .The duck swab separation rate of low pathogenic avian influenza was the highest ,which was 24 .6% ,and the following was chicken swab that reached 21 .5% ,and the goose swab separation rate was 11% .We isolated 6 HA subtypes including H3 ,H4 ,H6 ,H9 ,H10 ,and H11 in every live poultry wholesale market ,and the separation rate of H9 ,H6 and H4 subtypes was relatively high ,which could reach 11% ,6 .3% and 3 .4% ,respectively . Those results indicated that recessive infection of low pathogenic avian influenza virus was serious in live poultry wholesale mar-ket around the Dongting Lake area ,and it was a great threat to the occurrence of avian flu .

Objective To explore the influences of Dexmedetomidine for laparoscopic cholecystectomy on stress reaction and hepatic/renal functions. Methods Totally 100 cases with laparoscopic cholecystectomy were divided into two groups:Dexmedetormidine group and Propofol control group (n=50 for each group) according to the different anesthetic methods.The hemodynamic change,stress reaction and hepatic/renal function were measured and analyzed. Results Heart rate [(85.7±13.4)times /min vs.(62.7±9.9) times/min; (81.3±14.9) times/min vs.(60.3±8.8)times/min,t=2.296,2.714,P=0.045,0.022] and mean artery pressure(MAP )[(86.3±11.9)mm Hg vs.(66.5+11.7) mm Hg; (88.6±15.6) mm Hg vs.(68.7± 12.3) mm Hg,t=2.653,2.240,P=0.024,0.049] immediately at trachea cannula and 1 min after trachea cannula were significantly increased in Propofol control group as compared with Dexmedetomidine group.In contrast to Propofol control group,epinephrine[(680.1±112.3) pmol/L vs.(576.1±83.1)pmol/L; (705.4±127.6)pmol/L vs.648.8±105.3) pmol/L,(689.6±123.4) pmol/L vs.(628.2±94.3) pmol/L,t=2.628,2.242,2.224,P=0.019,0.039,0.040],norepinephrine[(3953.6±514.6) pmol/L vs.(3695.1±196.2) pmol/L; (3967.2=514.9) pmol/L vs.(4367.1±565.7) pmol/L; (4095.8±415.1) pmol/L vs.(3813.4 ± 513.7) pmol/L, t =2.454, 2.500, 2.255, P =0.032, 0.030,0.045] and hydrocortisone [(796.6±198.7) nmol/L vs.(698.7±176.3) nmol/L; (835.5+217.2) nmol/L vs.(783.7±201.9) nmol/L; (822.4±203.3) nmol/L vs.(720.6±188.1) nmol/L,t=2.334,2.167,2.189,P=0.033,0.044,0.043] immediately at trachea cannula,1 min and 5 min after trachea cannula were decreased in Dexmedetomidine group.There were not significantly differences in hepatic/renal function between the two groups (P＞ 0.05). Conclusions Dexmedetomidine is safe and effective for laparoscopic cholecystectomy in view of more stable hemodynamics,less stress reaction,and non influence on hepatic/renal function.

100 u/L 24 months later and another 38 year-old patient underwent surgical operation of ovaries bilaterally before UAE. Conclusions Temporary amenorrhea may not mean ovarian dysfunction or failure. The probability of ovarian dysfunction or failure after UAE is low, which mainly occur in the peirmenopausal patients. Consideration of the probability of inducing early ovarian failure, caution should be taken for UAE on the patients having ovarian surgery before. (J Intervent Radiol, 2006, 15: 472-475)