Objective To investigate the effect of radiofrequency ablation (RFA) of ventricular outflow tract septum on the left ventricular structure and function in experimental canine.Methods Healthy experimental dogs were used for this study.RFA of the myocardium at ventricular outflow tract septum was performed.Before RFA,thoracic ultrasound examination was used to determine the width of left ventricular outflow tract,the systolic interventricular septum thickness,left ventricular ejection fraction,etc.The ultrasound examination was performed immediately after RFA to check the above indexes.Ultrasound examination was employed one and 3 months after RFA to record the above indexes of the survived dogs,and pathological examination was made.Results Among the 10 experimental dogs,successful RFA was achieved in 9,and one dog died of ventricular fibrillation.In one dog RFA was successfully accomplished,but it died of respiratory inhibition due to over-deep anesthesia.Immediate success rate of surgery was 80％,eight dogs survived to the scheduled follow-up time point.The width of left ventricular outflow tract and the systolic interventricular septum thickness determined immediately after RFA as well as one and three months after RFA in the survived dogs were significantly different from the preoperative data (P＜0.05).Histopathologically,striking microscopic changes could be observed.No obvious changes in ECG and blood pressure were seen.Conclusion The results of this study indicate that RFA of ventricular outflow tract septum in experimental dogs is safe and effective,which provides useful parameters and experimental basis for further animal experiments and clinical trials.

Objective To investigate the distribution and antimicrobial resistance of Coagulase-negative staphylococci ( CoNS) isolated from cerebrospinal fluids in neurosurgical patients.Methods CoNS strains isolated from cerebrospinal fluids of neurosurgical patients were collected from Beijing Tiantan Hospital of Capital Medical University during January 2013 and December 2015.CoNS infection was diagnosed according to the standards of US Centers for Disease Control and Prevention, and the distribution and antimicrobial resistance of pathogenic CoNS strains were analyzed. Results A total of 19 756 cerebrospinal fluid specimens were collected and 1 386 bacterial strains were isolated, in which 650 (46.9%) were CoNS.Among 650 CoNS strains, 130 were diagnosed as the pathogen, and the top 4 CoNS species were Staphylococcus epidermidis (77/130, 59.2%), Staphylococcus hominis (18/130, 13.8%), Staphylococcus haemolyticus (11/130, 8.5%) and Staphylococcus capitis (9/130, 6.9%).The rest 520 CoNS strains were contaminating strains.According to antimicrobial susceptibility test, there were 103 strains of methicillin-resistant CoNS (MR-CoNS) accounting for 79.1% (103/130).And among 77 Staphylococcus epidermidis isolates, 67 were MR-CoNS strains (87.0%) .More than 90.0%Staphylococcus epidermidis isolates were sensitive to vancomycin and linezolid, and the rest CoNS strains were also highly sensitive to these two antibacterial agents.Conclusions CoNS plays an important role in post-surgery infection in neurosurgical patients, and Staphylococcus epidermidis is the dominant CoNS species.Most CoNS strains are methicillin-resistant, but are highly sensitive to vancomycin and linezolid.

Objective To explore the characteristic and its influencing factors of resilience in Chinese recruits to provide the scientific evidence for the mental health training. Methods Resilience Scale for Adults (RSA) ,Self-report Symptom Checklist 90( SCL-90), Eysenck Personality Questionnaire(EPQ) and General SelfEfficacy Scale (GSES) were applied to 2459 recruits(2231 males and 139 females, aged ( 19 ± 1.5 ) ) within two male recruits( 101.76 ± 14.06) was significantly higher than that of males (96.65 ± 15.62) ( t=4. 13, P＜0. 0l ) ;Recruits with College and above education have significantly higher RSA scores than those with junior high school education and senior high school education (P ＜ 0. 0l ). Between the only child group and non only child group, there was no significant difference in RSA total score , but significant difference existed only in three factors higher RSA group scored significantly higher in extraversion (Z = 19.13, P = 0.000), abreaction adjustment (Z =8.67, P = 0.600 ) and self-efficacy (Z = 19.48, P = 0.000 ), while scored significantly lower in the SCL-90 (Z =Resilience had significant positive correlation with extraversion, abreaction adjustment and self-efficacy, and negative correlation with the neuroticism and inhibition adjustment. Multiple linear regression analysis revealed that extraversion, neuroticism,abreaction adjustment/inhibition adjustment and self-efficacy had predictive ability to resilience( explain 41% ). Conclusion Chinese recruits have good resilience. Emotion Regulation (abreaction adjustment/inhibition adjustment), extraversion, neuroticism and self-efficacy are important influencing factors of resilience for Chinese recruits.

Due to the ability of overcoming both the dimensionality and the collinear problems of the spectral data, partial least squares ( PLS ) is in ever increasingly used for quantitative spectrometric analysis, especially for near-infrared spectrum, mid-infrared spectrum and Raman spectrum. In this work, an improved PLS algorithm is proposed for efficient information extraction and noise reduction. The spectral variables are clustering to several subsets, and several sub-models are built for each subset. Then, the sub-models are re-weighted and ensemble to the final model. Experiments on two near-infrared datasets ( octane number prediction in gasoline and nicotine prediction in tobacco leafs ) demonstrate that the new method provides superior prediction performance and outperformed the conventional PLS algorithm, and the root mean square error of prediction ( RMSEP) is reduced by 32% and 22%, respectively.

Objective To discuss the feasibility and effectiveness of transcatheter implantation of double-ring aortic valve stent through puncturing the tip of the heart under thoracotomy.Methods A novel double-ring aortic valve stent was independently designed by the authors.Three healthy goats were selected for this study.A small incision on the left anterolateral thoracic wall was made to expose the cardiac apex,than the puncturing of the left ventricular apex was performed to establish the working pathway.Guided by fluoroscopy,along a hard guide wire a double-ring aortic valve stent was inserted through a 22-French sheath to the site above the aortic valve.By utilizing the opened outer ring of the stent,the double-ring aortic valve stent was accurately placed at the bottom of the aortic valve sinus.Then,the balloon was inflated and the stent was released to substitute the original aortic valve of the experimental goat.The experiment results were evaluated immediately after the procedure.Results Transcatheter aortic valve implantation (TAVI) was successfully accomplished in all the three experimental goats.DSA was performed immediately after the procedure and anatomy evaluation indicated that the position of the implanted artificial aortic valve was satisfactory,which could replace the work of original valve.Conclusion It is technically feasible and clinically effective to use this novel double-ring aortic valve stent to perform TAVI through transapical route by puncturing the left ventricular apex.

Objective To evaluate the feasibility and safety of a delivery pathway for the performance of percutaneous left atrial appendage (LAA) occlusion in experimental canine models. Methods Transseptal puncture was performed via femoral vein approach under fluoroscopic and angiographic guidance in 12 experimental dogs. A pigtail catheter was advanced into the left atrium (LA), which was followed by LA angiography. The diameters of the neck of LAA were measured on LAA angiogram obtained in appropriate projection. After the delivery sheath was advanced along the wire into LA, a pigtail catheter was inserted into the ostium of the LAA and the sheath was then advanced over the pigtail into the LAA. LAA angiography was then performed through the delivery sheath to confirm the position of the delivery sheath. One hour after the procedure both electrocardiography (ECG) and transthoracic echocardiography (TTE) were carried out in five dogs to check the results, immediately after which the five dogs were sacrificed to macroscopically observe the damages of the puncture site of inter-atrial septum as well as inside the LA and LAA. One hour and 2 weeks after the procedure TTE was conducted in the remaining 7 dogs and these dogs were followed up for one month. Results One dog died of pericardial tamponade during the operation. In 8 dogs the LAA was clearly displayed in the projection position of right anterior oblique (RAO) 30°/cranial (CRA) 20°,while in 3 dogs the LAA was well visualized in the projection position of RAO 30° , and in one dog in the projection position of RAO 30°/caudal (CAU) 20°. The diameter of LAA neck was (13.6 ± 5.2) mm. The delivery sheath was safely advanced into the LAA along the pigtail catheter in all dogs, and no air embolism, thrombus or pericardial tamponade occurred. Hematoma at puncture point of groin occurred in 2 dogs, which was absorbed through pressure dressing. Macroscopic examination of the heart performed immediately after the operation showed that no bloody pericardial effusion was found, and mild hematoma at posterior wall of LA was seen in one dog and mild damage of the upper-margin intima of LAA was noted in 2 dogs. The mean fluoroscopy time was (10.1 ± 2.5) minutes and the mean operation time was (58 ± 12) minutes. TEE showed no pericardial effusion 2 weeks after the procedure. During the follow-up period of one month no sudden death, stroke or infection occurred. Conclusion This method of placing the delivery sheath into the LAA is clinically safe and effective, and it can reliably establish a pathway to advance the LAA occluder into LAA.

Human beta defensin 2 (HBD-2) may play an important role in human defense against infection. Its antimicrobial capacity has been fully documented in in vitro study. In order to evaluae its in vivo effects, we developed an HBD-2 transgenic mouse model. The HBD-2 minigene containing CMV promoter, full length of HBD-2 cDNA and BGH polyA tail was generated by PCR amplification and introduced into the fertilized oocytes of C57 X ICR hybridized mouse by microinjection, and offspring were produced. DNA was isolated from the tails of the mouse pups, and the HBD-2 minigene incorporation was analyzed by PCR using HBD-2 specific primers. The HBD-2 gene expression in the multi-tissues of transgenic mice was determined at mRNA level by RT-PCR and at peptide level by immunohistological staining with the use of HBD-2 monoclonal antibody. The results showed that among 17 F0 transgenic mice, HBD-2 positive signal was determined by PCR in 4 mice, suggesting that HBD-2 minigene has been incorporated into the offspring mice. Meanwhile, a widespread expression of HBD-2 mRNA and peptide was detected in the F1 transgenic mice's multi-tissues such as trachea, lung, intestine, esophagus, testis, spleen, skin, endothelium and brain.
Animals ; Anti-Infective Agents ; Humans ; Mice ; Mice, Inbred C57BL ; Mice, Inbred ICR ; Mice, Transgenic ; Models, Animal ; Polymerase Chain Reaction ; RNA, Messenger ; analysis ; biosynthesis ; genetics ; beta-Defensins ; biosynthesis ; genetics