Objective To establish a method for testing isolated mitral valve in vitro and quantitatively evaluate the effect of transcatheter edge-to-edge repair technology(TEER)on functional mitral regurgitation(FMR)(non-A2-P2 regurgitation).Methods In this study,an FMR(non-A2-P2 regurgitation)model was developed by dilating the annulus orifice and displacing the papillary muscle in isolated porcine mitral valve.The hydrodynamics characteristics of 6 valves were tested by a pulsatile flow testing system under different physiological and pathological conditions before and after TEER.Results The results show that the valve regurgitation improved from moderate-severe[regurgitant fraction(60.2±17.5)％]to mild-moderate[regurgitant fraction(34.7±12.0)％]by repair(P＜0.001).The EOA[(3.8±1.6)cm2 vs.(2.2±0.5)cm2,P＜0.001]and the forward cross valve pressure difference[(1.8±1.3)mmHg vs.(3.8± 1.8)mmHg,P＜0.001],which characterize the forward flow performance of the valve,were compared before and after repair,and the differences were statistically significant.At the same time,the repair caused valve stenosis(the effective orifice area decreased by 40％and the positive differential pressure increased by 110％),but the valves was still within the normal physiological range,and no iatrogenic stenosis was caused.Conclusions It can be seen that TEER has an effect on FMR.This study provides validation and evaluation methods in vitro for expanding indications and improving TEER,and reference for developing standards of transcatheter valve repair testing in vitro.

As a rapidly developing frontier discipline, structural biology has penetrated into every field of life science research. The course of “Structural Biology” plays an important role in expanding the knowledge system of undergraduate students and promoting students’ scientific spirit and innovation. For the high-quality training of highly skilled talents, we aimed to promote the original innovation of students, the ability of thinking, and the ability of engineering practice. The trinity education concept, including shape of the value, passing on knowledge, and ability cultivation, was applied. During the reform, we explored a step-by-step course content and searched for factors involved in ideological and political education. Based on the problem-based learning (PBL) method, a hybrid teaching model was designed to cultivate the problem-thinking and problem-solving skills of students. Meanwhile, a number of evaluation systems for students and teachers were established, which may be generally adopted for the course of “Structural Biology”. The survey data suggested that the exploration has a good effect on teaching and training and is conducive to the cultivation of research-oriented, comprehensive, innovative talents under the background of “New Engineering”.

Formaldehyde is a prevalent organic solvent in industrial and indoor environment,which can seriously harm human health,so it is of great significance to develop highly sensitive formaldehyde sensors with fast response,low detection limit and long life.In this study,the NiO-In2O3 composite structure was prepared using indium-based metal organic framework(In-MOF)as the precursor,and the formaldehyde gas sensor was constructed with In2O3 and NiO-In2O3 composite structure as the sensitive material.The results demonstrated that the In2O3 material had a microflower-like structure,while the NiO-In2O3 composite structure was composed of NiO nanoparticles attached to the surface of In2O3.The sensor exhibited excellent detection performance for formaldehyde in the environment of relative humidity of 33%and 75%,especially the response characteristic of the NiO-In2O3 composite structure sensor to formaldehyde was considerably better than that of the In2O3 sensor under the same test conditions,which was closely related to the catalytic effect of NiO and the heterogeneous structure formed between NiO and In2O3.The NiO-In2O3 composite structure sensor had a response value of 21.3 and 12.6 to 10 μL/L formaldehyde when the relative humidity was 33%and 75%at 200℃.The response/recovery time was 4/6 s and 7/10 s,and the limit of detection(LOD)was 1.2×10-7 μL/L and 4.1×10-5 μL/L respectively.Meanwhile,the sensor had excellent selectivity and long-term stability.This sensor showed a wide application prospect in the field of high-performance detection of low concentration of formaldehyde gas.

Objective To explore clinical effect of manipulation reduction combined with vertebral plasty on osteoporotic compression fractures(OVCFs).Methods Totally 61 patients with OVCFs treated from January 2022 to March 2024 were randomly divided into self-made spinal locator positioning with manipulation reduction group(treatment group)and traditional Kirchner positioning group(control group).There were 30 patients in treatment group,including 4 males and 26 females,aged from 61 to 87 years old with an average of(73.61±7.17)years old;body mass index(BMI)ranged from 15.24 to 28.89 kg·m-2 with an average of(23.90±3.20)kg·m-2;bone mineral density T value ranged from-4.90 to-2.50 SD with an avergae of(-3.43±0.75)SD;fracture to operation time was 6.50(4.00,10.25)d;10 patients were grade Ⅰ,13 patients were grade Ⅱ,and 7 patients were grade Ⅲ according to Genant classification of fracture compression.There were 31 patients in control group,in-cluding 7 males and 24 females,aged from 61 to 89 years old with an average of(73.63±8.77)years old;BMI ranged from 18.43 to 27.06 kg·m-2 with an average of(23.67±2.35)kg·m-2;bone mineral density T value ranged from-4.60 to-2.50 SD with an avergae of(-3.30±0.68)SD;fracture to operation time was 6.00(3.00,8.00)d;1l patients were grade Ⅰ,9 patients were grade Ⅱ,and 11 patients were grade Ⅲ according to Genant classification of fracture compression.The puncture times,X-ray fluoroscopy times and puncture time between two groups were observed and compared.Visual analogue scale(VAS),Japanese Orthopaedic Association(JOA)and timed up and go test(TUGT)were observed and compared before operation,3 d and 1 month after operation.Results All patients were followed up for 1 to 3 months with an average of(2.10±0.80)months.Puncture times,X-ray fluorosecopy times and puncture time in treatment group were 5.00(4.00,6.00)times,(29.53±5.89)times and 14.83(12.42,21.20)min,respectively,while those in control group were 7.00(6.00,8.00)times,(34.58±5.33)times,22.19(17.33,27.01)min,treatment group was better than those of control group(P＜0.05).There were no significant differences in preoperative VAS,JOA and TUGT between two groups(P＞0.05).VAS,JOA and TUGT in both groups were sig-nificantly improved after opeation(P＜0.05).On the third day after operation,JOA score of treatment group was 23.00(20.75,25.00),which was higher than that of control group 20.00(19.00,23.00)(P＜0.05).TUGT of treatment group was 6.26(5.86,6.57)s,which was better than that of control group 6.90(6.80,7.14)s(P＜0.05).Bone cement leakage occurred with 1 patient in treatment group and 2 patients in control group.Conclusion The optimal scheme of self-made spinal locators for lo-cating descending verteboplasty combined with traditional Chinese medicine reduction manipulation for OVCF patients could reduce the number of intraoperative puncture times,shorten puncture times and reduce number of X-ray fluoroscopy times,and have advantages over the simple positioning of Kirschn's needle in restoring short-term lumbar function and standing and walk-ing ability of postoperative patients.

Objective To retrospectively analyze the ultra-fast track anesthesia(UFTA)methods and perioperative anesthesia management experiences of transcatheter mitral valve edge-to-edge repair(TEER)in the treatment of functional mitral regurgitant.Methods In this retrospective study,patients underwent the TEER procedure and received UFTA in Fuwai Yunnan Hospital,from May 2022 to September 2022 for heart failure combined with moderate to severe or severe functional mitral regurgitant were included.Baseline,preoperative complications,cardial function and anesthesia classification,amino-terminal probrain natriuretic peptide(NT-proBNP),ultrasound examination results,surgery time,extubation time,intraoperative anesthetic and vasoactive drug,complications related to TEER and UFTA,perioperative,and postoperative 30-day and one-year follow-up data were collected.All perioperative clinical data were recorded and analyzed.Results A total of 30 patients were enrolled,11 patients(36.7％)were female,mean age was(63.6±6.1)years,NYHA classification IV 14 patients(46.7％),left ventricular ejection fraction(LVEF)(36.0±8.1)％,the end-diastolic volume of the left ventricle(66.0±8.2)mm,mitral regurgitation 4+14 patients(56.7％),3+17 patients(43.3％),NT-proBNP(1 934.1±1 973.5)pg/ml,1 patient(3.3％)used high-dose vasoactive drugs during surgery.All patients did not experience nausea,vomiting,delirium,respiratory depression,perioperative transesophageal echocardiography-related gastrointestinal bleeding,pericardial effusion,cerebrovascular accidents,emergency surgery or secondary intervention,or other serious adverse events within 24 hours after surgery.No 30-day all-cause death occurred;the mean postoperative hospital stay was(7.4±2.8)days.All patients completed one-year follow-up,LVEF(37.6±11.1)％,the end-diastolic volume of the left ventricle(63.2±8.6)mm,mitral regurgitation 2+7 patients(23.3％),1+23 patients(76.7％),NT-proBNP(1 949.2±2 576.6)pg/ml.Conclusions Ultra-fast track anesthesia can be safely applied to TEER in treating functional mitral regurgitant patients.

For the past 30 years,percutaneous balloon mitral valve dilatation has been performed under the guidance of X-rays and bedside ultrasound.However,there are still some cases of mitral valve stenosis in the large atrium where balloon dilation failed.Intraperitoneal ultrasound-guided percutaneous balloon mitral valve plasty is accurate and feasible,which can reduce the occurrence of complications and improve the success rate of such elderly complex cases.Two patients with severe mitral stenosis underwent percutaneous balloon mitral valve plasty guided by intracardiac ultrasound.The operations were successful without any complications,which can provide reference for clinical treatment of mitral stenosis.

This study was aimed at creating an engineered strain of Bacillus subtilis for efficient expression of biologically active type 2 toxin B(TcdB2)derived from a highly virulent strain of Clostridium difficile.The TcdB2 gene was cloned from ST1/RT027 strain genome DNA,incorporated into the PHT01 vector,and then transformed into B.subtilis strain WB800N for prokaryotic expression.Cell toxicity assays revealed that the recombinant TcdB2 exhibited cytotoxic effects in various cells.The engineered B.subtilis strain effectively expressed biologically active TcdB2,thus providing a basis for further exploration of the pathogenic mechanisms of highly virulent strains of C.difficile and establishing a foundation for potential vaccine can-didate targets.