人参内生菌的研究进展

内生菌由细菌、真菌、古菌和原生生物组成，它们生活在植物的活体组织中，具有丰富的次级代谢产物多样性。人参内生菌在人参的生长发育、次级代谢产物的生成和环境适应等方面均有重要的促进作用，对人参的产量和品质有较大影响。随着人们在微生物领域研究的深入，高通量测序技术已经成为研究植物内生菌的重要方法。文章主要从人参内生菌分离与鉴定研究方法、人参内生菌的多样性、人参内生菌及其次级代谢产物的活性、人参内生菌对宿主的影响等4个方面对人参内生菌近年来的研究进展进行讨论，并对其发展方向提出展望，以期为药用植物内生菌研究和品质改良提供新思路、新方法。     

Atrial fibrillation after cardiac surgery: A systematic review and meta-analysis

ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established.     

VAC结合游离植皮治疗儿童大面积皮肤缺损疗效观察及对患儿生活质量的影响

目的:探讨负压创面治疗技术(Vacuum assisted closure,VAC)结合游离植皮治疗儿童大面积皮肤缺损疗效及对患儿生活质量的影响。方法:选取2015年2月-2019年2月笔者医院收治的60例大面积皮肤缺损患儿作为研究对象,按照随机数表法分为干预组和对照组,每组30例。对照组采用游离植皮术治疗,干预组在对照组的基础上结合VAC治疗,以皮片成活时间、皮片成活率、换药次数及住院天数评估疗效,以长海痛尺分级法评估患儿疼痛等级,以抑郁自评量表(Self-rating depression scale,SDS)、焦虑自评量表(Self-rating anxiety scale,SAS)评估患儿心理状态,以术后不良反应发生率评估患儿预后情况,以自制生活质量表评估患儿生活质量水平。结果:干预组患儿皮片成活时间、换药次数与住院天数均小于对照组,差异有统计学意义(P<0.05)。干预组患儿皮片成活率为93.33%高于对照组的76.67%,差异有统计学意义(P<0.05)。干预组治疗后疼痛感、SDS与SAS评分低于治疗前,且低于对照组,差异有统计学意义(P<0.05)。干预组患儿术后不良反应发生率为6.67%显著低于对照组23.33%,差异有统计学意义(P<0.05)。两组治疗前活动能力、心理健康及社交能力均低于治疗后,干预组治疗后活动能力、心理健康及社交能力均高于对照组(P<0.05)。结论:VAC结合游离植皮治疗儿童大面积皮肤缺损疗效显著,能有效降低患儿生理疼痛与心理焦虑,减少伤口感染等不良反应的发生,提高患儿生活质量,具有推广价值。     

Unconditional Positivity-Preserving and Energy Stable Schemes for a Reduced Poisson-Nernst-Planck System

The Poisson-Nernst-Planck (PNP) system is a widely accepted model for simulation of ionic channels. In this paper, we design, analyze, and numerically validate a second order unconditional positivity-preserving scheme for solving a reduced PNP system, which can well approximate the three dimensional ion channel problem. Positivity of numerical solutions is proven to hold true independent of the size of time steps and the choice of the Poisson solver. The scheme is easy to implement without resorting to any iteration method. Several numerical examples further confirm the positivity-preserving property, and demonstrate the accuracy, efficiency, and robustness of the proposed scheme, as well as the fast approach to steady states.     

Organic and Inorganic Mercury in Biological Samples of Flouresecent Lamp Industries Workers and Health Risks

Objective The present study aims to investigate the concentrations of Hg and its aspects methyl mercury(Me-Hg) and inorganic mercury(I-Hg) in the biological samples(BSs) of fluorescent lamp industries workers(FLIWs).Methodology Different BSs including red blood cells(RBCs),plasma,urine,hair and nails were collected from the workers exposed to Hg and unexposed persons were selected as control group to measure both the T-Hg concentration as well as its species in different biological samples through quantitative analysis.Health data was collected through questionnaire survey.Results The mean concentrations of T-Hg(31.9 μg/L),Me-Hg(27.7 μg/L),and I-Hg(5.36 μg/L) in RBCs were found significantly(P 0.001) higher among the workers(n = 40) as compared to the control group(n = 40).Similarly the mean Hg concentrations in plasma,urine,hair and nails were also significantly higher among the workers than the control group.The statistical relation between Hg concentration and demographic characteristics observed that workers experience and fish consumption has increased the Hg concentration while age,weight and smoking found no significant effect on Hg concentration in the BSs.Conclusion The study observed that the workers were highly exposed to high concentration of Hg and they are at a high health risk.     

Intrathecal catheterisation after observed accidental dural puncture in labouring women: update of a meta-analysis and a trial-sequential analysis

BackgroundOur meta-analysis from 2013 showed that inserting a catheter intrathecally after an observed accidental dural puncture can reduce the need for epidural blood patch in labouring women requesting epidural analgesia. We updated our conventional meta-analysis and added a trial-sequential analysis (TSA).MethodsA systematic literature search was conducted to identify studies that compared inserting the catheter intrathecally with an epidural catheter re-site or with no intervention. The extracted data were pooled and the risk ratio (RR) and 95% confidence interval (95%CI) for the incidence of post-dural puncture headache (PDPH) was calculated, using the random effects model. A contour-enhanced funnel plot was constructed. A TSA was performed and the cumulative Z score, monitoring and futility boundaries were constructed.ResultsOur search identified 13 studies, reporting on 1653 patients, with a low risk of bias. The RR for the incidence of PDPH was 0.82 (95%CI 0.71 to 0.95) and the RR for the need for epidural blood patch was 0.62 (95%CI 0.49 to 0.79); heterogeneity of both analyses was high. The TSA showed that the monitoring or futility boundaries were not crossed, indicating insufficient data to exclude a type I error of statistical analysis. Contour-enhanced funnel plots were symmetric, suggesting no publication bias.ConclusionsConventional meta-analyses showed for the first time that intrathecal catheterisation can reduce the incidence of PDPH. However, TSA did not corroborate this finding. Despite increasing use in clinical practice there is no firm evidence on which to base a definite conclusion.     

A Simple Dressing Technique Following Dermofasciectomy and Full Thickness Skin Grafting of the Fingers in the Treatment of Severe Dupuytren’s Contracture

Dupuytren’s disease with severe finger contractures and recurrent contractures following previous surgery often have extensive skin involvement. In these severe cases, excision of the diseased chord along with the involved skin is a good option to reduce the risk of recurrance. The resulting skin defect can be covered with a full thickness skin graft (FTSG) or a cross finger flap. Cross finger flaps have donor finger morbidity and hence a full thickness graft is usually preferred. The FTSG extending to the midlateral margins on both sides of the finger reduces the risk of joint contracture due to graft shrinkage. Once the FTSG is sutured in place, the standard practice is to compress and secure the graft to its recipient bed with a tie-over dressing and this can be time consuming. We present a simple dressing technique to secure the FTSG without the need for a tie-over dressing.