AIM:Nitroxyl ( HNO) increases myofilament Ca 2+responsiveness relative to increases in intracel-lular Ca2+in cardiac muscle.In this study, we further investigated this effect of HNO on trabecular muscles from phospho-lamban knockout ( PLB-KO) and wide-type ( WT ) mice using a novel HNO donor , 1-nitrosocyclohexyl acetate ( NCA ) . METHODS:Trabecular muscles were dissected from the right ventricles of the rat hearts and mounted between a force transducer and a motor arm.The muscles were superfused with K-H solution (pH 7.4) at room temperature.Fura-2 was loaded into the trabecular muscles via electrophoresis .The length of the sarcomere was set to 2.2~2.3μm.During stead-y-state activations, the maximal Ca2+-activated force and Ca2+required for 50% activation were measured.RESULTS:The intracellular Ca 2+transients and force of the PLB-KO muscles at baseline were higher than those of the WT muscles and exhibited a negative force-frequency relationship (FFR).NCA (2.5μmol/L) increased systolic force in both PLB-KO group and WT group at any given [Ca2+]o.However, there was more dramatic increase in the force development due to moderate increases in the intracellular Ca 2+transients in the WT muscles when external Ca 2+increased from 1.5 to 4.5 mmol/L under NCA.NCA did not affect the negative FFR in PLB-KO muscle.Steady-state force-Ca2+relations obtained from skinned muscles were not different between the 2 groups, while NCA increased Ca2+responsiveness in skinned mus-cles from both PLB-KO and WT mice.CONCLUSION:HNO increases force development in both PLB-KO and WT mus-cles as a result of increases in myofilament Ca 2+responsiveness .The increased intracellular Ca 2+transients are accompa-nied by greater force development in WT mice , suggesting that HNO improves Ca 2+activation and establishes HNO as a positive inotropic agent with novel mechanisms .

Objective To understand the incidence of nosocomial infections for providing basis for the development of prevention and control measures.Methods All the hospitalized patients were investigated,data collection used by nosocomial infection surveillance system,the results were statistically analyzed.Results Nosocomial infections occurred in 46 case-times with the infection rate of 3.04％,the top 3 prevalence rates were in ICU(46.15％),department of hematology(21.87％),department of neurosurgery (1 1.76％).The main infection sites were lower respiratory tract (36.96％) and upper respiratory tract (28.26％).The utilization rate of antibiotics was 44.09％.There were 183 patients who received etiology examination with the submission rate of 32.28％.Conclusion The investigation of prevalence of nosocomial infections can contribute to understanding of the incidence of nosocomial infections,and taking interventions to the key departments,strengthening the clinical specimens submission,and standardizing the reasonable use of antibiotics can decrease the incidence of nosocomial infections.

Objective To observe the effect of acupuncture and acupoint injection on dementia in elder.Methods 38 old dementia patients were divided into senile dementia(Alzheimer's disease,17 cases)and vascular dementia(21 cases).They were treated with acupuncture and acupoint injection with Piracetam.Results 7 cases improved in senile dementia patients,while 2 cases were excellent,7 cases were good,9 cases improved in vascular dementia patients.Conclusion Acupuncture and acupoint injection with Piracetam is more effective on senile dementia than vascular dementia.

Objective To assess the left ventricular systolic function in young strength male athletes by three-dimensional speckle tracking echocardiography (3D-STE).Methods A total of 45 young strength male athletes (athlete group) and 30 healthy young men (control group)were enrolled.Traditional echocardiography combined with 3D-STE were applied for all the subjects to obtain heart rate (HR),left ventricular end-diastolic diameter (LVEDD),the thickness of interventricular septum (IVS) and posterior wall thickness (PWT),relative wall thickness (RWT),left ventricular end-diastolic volume (EDV),endsystolic volume (ESV),left ventricular ejection fraction(LVEF),stroke volume (SV),left ventricular mass (LVM),left ventricular global longitudinal strain (GLS),global circumferential strain (GCS),global area strain (GAS),global radial strain (GRS).Results There were a significant increase inLVEDD,IVS,PWT,RWT,EDV,ESV,SV,LVM and significant decrease in HR,GLS,GCS,GAS and GRS in athlete group compared with the control group (P ＜ 0.05).However,there was no significant difference in LVEF between two groups (P ＞0.05).Conclusions There are subclinical changes of left ventricular systolic functionin of young strength male athletes.3D-STE can accurately assess the changes,and provide reliable information for clinical assessment of athletes' heart function.

Objective:To establish a prediction model using the random forest (RF) and support vector machine (SVM) algorithms to achieve the numerical and classification predictions of the gamma passing rate (GPR) for volumetric arc intensity modulation (VMAT) validation.Methods:A total of 258 patients who received VMAT radiotherapy in the 1 st Affiliated Hospital of Wenzhou Medical University from April 2019 to August 2020 were retrospectively selected for patient-specific QA measurements, including 38 patients who received VMAT radiotherapy for head and neck, and 220 patients who received VMAT radiotherapy for chest and abdomen. Thirteen complexity parameters were extracted from the patient′s VMAT plans and the GPRs for VMAT validation under the analysis criteria of 3%/3 mm and 2%/2 mm were collected. The patients were randomly divided into a training cohort (70%) and a validation cohort (30%) , and the complexity parameters for the numerical and classification predictions were screened using the RF and minimum redundancy maximum correlation (mRMR) method, respectively. Complexity models and mixed models were established using PTV volume, subfield width, and smoothness factors based on the RF and SVM algorithms individually. The prediction performance of the established models was analyzed and compared. Results:For the validation cohort, the GPR numerical prediction errors of the complexity models based on RF and SVM under the two analysis criteria are as follows. The root-mean-square errors (RMSEs) under the analysis criterion of 3%/3 mm were 1.788% and 1.753%, respectively; the RMSEs under the analysis criterion of 2%/2 mm were 5.895% and 5.444%, respectively; the mean absolute errors (MAEs) under the analysis criterion of 3%/3 mm were 1.415% and 1.334%, respectively, and the MAEs under the analysis criteria of 2%/2 mm were 4.644% and 4.255%, respectively. For the validation cohort, the GPR numerical prediction errors of the mixed models based on RF and SVM under the two analysis criteria were as follows. The RMSEs under the analysis criterion of 3%/3 mm were 1.760% and 1.815%, respectively; the RMSEs under the analysis criterion of 2%/2 mm were 5.693% and 5.590%, respectively; the MAEs under the analysis criterion of 3%/3 mm were 1.386% and 1.319%, respectively, and the MAEs under the analysis criteria of 2%/2 mm were 4.523% and 4.310, respectively. For the validation cohort, the AUC result of the GPR classification prediction of the complexity models based on RF and SVM were 0.790 and 0.793, respectively under the analysis criterion of 3%/3 mm and were 0.763 and 0.754, respectively under the analysis criterion of 2%/2 mm. For the validation cohort, the AUC result of the GPR classification prediction of the mixed models based on RF and SVM were 0.806 and 0.859, respectively under the analysis criterion of 3%/3 mm and were 0.796 and 0.796, respectively under the analysis criterion of 2%/2 mm cohort.Conclusions:Complexity models and mixed models were developed based on the RF and SVM method. Both types of models allow for the numerical and classification predictions of the GPRs of VMAT radiotherapy plans under analysis criteria of 3%/3 mm and 2%/2 mm. The mixed models have higher prediction accuracy than the complexity models.

OBJECTIVE To compare the anticoagulant effectiveness and safety of new oral anticoagulants （NOACs）and warfarin after heart valve replacement ，and to provide evidence-based reference for clinical drug use. METHODS Retrieved from PubMed，Cochrane Library ，Embase，Web of Science ，CNKI，Wanfang database and VIP ，clinical studies about the use of NOACs versus warfarin after heart valve replacement were collected during the inception to July 2021. After literature screening and data extrac tion，the quality of included randomized controlled trials （RCTs）were evaluat ed by bias risk assessment tool recommended by Cochrane system evaluator manual 5.2.0. After the quality of the included cohort studies was evaluated by Newcastle-Ottawa scale （NOS），RevMan 5.3 software was used for meta-analysis and sensitivity analysis. RESULTS A E-mail：carolmeng_0813@163.com total of 9 studies involving 4 962 patients were included ，of which 7 were RCTs and 2 were cohort studie s. Results of meta-analysis showed that after biological valve replacement/repair ，the incidence of stroke and systemic embolism （SSE）[OR＝0.71，95％CI（0.52，0.97），P＝0.03]，major bleeding [OR ＝0.40，95％CI （0.30，0.54），P＜0.000 01] and intracranial hemorrhage [OR ＝0.20，95％CI（0.04，0.95），P＝0.04] in trial group were significantly lower than warfarin group ；there was no significant difference in all-cause mortality between 2 groups [OR ＝1.25，95％CI（0.88， 1.79），P＝0.22]. After mechanical valve replacement/repair ，there were no significant difference in the incidence of SSE [OR ＝1.52， 95％CI（0.04，60.29），P＝0.82] or all-cause mortality [OR ＝0.26，95％CI（0.04，1.84），P＝0.18] between 2 groups. The results of subgroup analysis according to the follow-up time showed that after biological valve replacement/repair ，the incidence of SSE in trial group was significantly lower than that in control group when the follow-up time was ≤3 months [OR ＝0.20，95％CI（0.06， 0.74），P＝0.03]；but there was no significant difference in the incidence of major bleeding between 2 groups [OR ＝0.67，95％CI （0.19，2.38），P＝0.53]；when the follow-up time was longer than 3 months，there was no statistical significance in the incidence of SSE between 2 groups [OR ＝0.74，95％CI（0.54，1.02），P＝0.07]，while the incidence of major bleeding in trial group was significantly lower than control group [OR ＝0.39，95％CI（0.29，0.52），P＜0.001]. Subgroup analysis by study type showed that after biological valve replacement/repair ，the incidence of SSE in the RCT in trial group was significantly lower than that in control group [OR ＝0.51，95％CI（0.29，0.92），P＝0.03]，but there was no significant difference in the incidence of major bleeding between 2 groups[OR＝0.58，95％CI（0.33，1.03），P＝0.06]. In cohort study ，there was no significant difference in the incidence of SSE between 2 groups [OR ＝1.03，95％CI（0.40，2.66），P＝0.95]，while the incidence of major bleeding in trial group was significantly lower than control group [OR ＝0.20，95％CI（0.06，0.74），P＜0.001]. Sensitivity analysis results showed that the results of the above-mentioned meta-analysis were relatively robust. CONCLUSIONS For the patients underwent biological valve replacement/repair，the effectiveness and safety of NOACs are better than or similar to those of warfarin ；for the patients underwent mechanical valve replacement/repair ，there is no significant difference in the effectiveness and safety between NOACs and warfarin.

OBJECTIVE: The population density and diversity of Sinomenium acutum (Menispermaceae) have been greatly reduced recently by overharvesting for medicinal purposes in China. Therefore, it is urgent that the remaining populations are investigated, and that strategies for the utilization and conservation of this species are developed. This study aimed to find the possible glacial refugia and define the genetic diversity of S. acutum for its proper utilization and conservation. METHODS: A total of 77 S. acutum samples were collected from four locations, Qinling Mountains, Daba Mountains, Dalou Mountains, and Xuefeng Mountains, in subtropical China. Genetic diversity among and between these populations were phylogenetically analyzed using four chloroplast DNA molecular markers (atpI-atpH, trnQ-5'rps16, trnH-psbA and trnL-trnF). RESULTS: A total of 14 haplotypes (C1 to C14) were found in collected samples. Haplotypes C1 and C3 were shared among all populations, with C3 as the ancestral haplotype. Haplotypes C11 and C12 diverged the most from C3 and other haplotypes. No obvious phylogeographic structure was found in four locations using the GST/NST test. There is no evidence of rapid demographic expansion in S. acutum based on the mismatch distribution, and the results of Tajima's D test, and Fu's FS test. Our analyses of molecular variance revealed a high level of genetic variation within populations. In contrast, the genetic differentiation among S. acutum populations was low, indicating frequent gene flow. CONCLUSION Xuefeng, Dalou, and Daba Mountains were possible glacial refugia for the populations of S. acutum. C1, C3, C11 and C12 haplotypes of S. acutum should be carefully preserved and managed for their genetic value.