Colorectal anastomotic leakage: Aspects of prevention, detection and treatment

All colorectal surgeons are faced from time to time with anastomotic leakage after colorectal surgery. This complication has been studied extensively without a significant reduction of incidence over the last 30 years. New techniques of prevention, by innovative anastomotic techniques should improve results in the future, but standardization and "teachability" should be guaranteed. Risk scoring enables intra-operative decision-making whether to restore continuity or deviate. Early detection can lead to reduction in delay of diagnosis as long as a standard system is used. For treatment options, no firm evidence is available, but future studies could focus on repair and saving of the anastomosis on the one hand or anastomotical breakdown and definitive colostomy on the other hand.

Systematic review of cystic duct closure techniques in relation to prevention of bile duct leakage after laparoscopic cholecystectomy

AIM To study the effect of different techniques of cystic duct closure on bile leakage after laparoscopic cholecystectomy(LC) for biliary disease.METHODS A systematic search of MEDLINE, Cochrane and EMBASE was performed. Rate of cystic duct leakage(CDL) was the primary outcome. Risk of bias was evaluated. Odds ratios were analyzed for comparison of techniques and pooled event rates for non-comparative analyses. Pooled event rates were compared for each of included techniques.RESULTS Out of 1491 articles, 38 studies were included. A total of 47491 patients were included, of which 38683(81.5%)underwent cystic duct closure with non-locking(metal)clips. All studies were of low-moderate methodological quality. Only two studies reported separate data on uncomplicated and complicated gallbladder disease. For overall CDL, an odds ratio of 0.4(95%CI: 0.06-2.48)was found for harmonic energy vs clip closure and an odds ratio of 0.17(95%CI: 0.03-0.93) for locking vs non-locking clips. Pooled CDL rate was around 1% for harmonic energy and metal clips, and 0% for locking clips and ligatures. CONCLUSION Based on available evidence it is not possible to either recommend or discourage any of the techniques for cystic duct closure during LC with respects to CDL,although data point out a slight preference for locking clips and ligatures vs other techniques. No separate recommendation can be made for complicated gallbladder disease.

A Review on Distribution Model for Mobile Agent-Based Information Leakage Prevention

With the continuous use of cloud and distributed computing, the threats associated with data and information technology (IT) in such an environment have also increased. Thus, data security and data leakage prevention have become important in a distributed environment. In this aspect, mobile agent-based systems are one of the latest mechanisms to identify and prevent the intrusion and leakage of the data across the network. Thus, to tackle one or more of the several challenges on Mobile Agent-Based Information Leakage Prevention, this paper aim at providing a comprehensive, detailed, and systematic study of the Distribution Model for Mobile Agent-Based Information Leakage Prevention. This paper involves the review of papers selected from the journals which are published in 2009 and 2019. The critical review is presented for the distributed mobile agent-based intrusion detection systems in terms of their design analysis, techniques, and shortcomings. Initially, eighty-five papers were identified, but a paper selection process reduced the number of papers to thirteen important reviews.

Integrated approach to colorectal anastomotic leakage: Communication, infection and healing disturbances

Colorectal anastomotic leakage(CAL) remains a major complication after colorectal surgery. Despite all efforts during the last decades, the incidence of CAL has not decreased. In this review, we summarize the available strategies regarding prevention, prediction and intervention of CAL and categorize them into three categories: communication, infection and healing disturbances. These three major factors actively interact during the onset of CAL. We aim to provide an integrated approach to CAL based on its etiology. The intraoperative air leak test, intraoperative endoscopy, radiological examinations and stoma construction mainly aim to detect and to prevent communication between the intra- and extra-luminal content. Other strategies including postoperative drainage, antibiotics, and infectious-parameter evaluation are intended to detect and prevent anastomotic or peritoneal infection. Most currently available interventions for CAL focus on the control of communication and infection, while strategies targeting the healing disturbances such as lifestyle changes, oxygen therapy and evaluation of metabolic biomarkers still lack wide clinical application. This simplified categorization may contribute to an integrated understanding of CAL. We strongly believe that this integrated approach should be taken into consideration during clinical practice. An integrated approach to CAL could contribute to a better understanding of the etiology of CAL and eventually better patient outcome.

A novel coating technology for fast sealing of air leakage in underground coal mines

Air leakage in underground coal mines presents a serious hazard for coal production and the safety of miners.Coating technology is commonly used as an efficient means for preventing air leakage.To address existing problems with high dust concentrations in large operations involving complex processes and the high cost of traditional coating technology,a novel coating technology that ensures intrinsic safety by utilizing water pressure and wind pressure was developed.This new coating technology was designed to suction and spray,and the technical parameters of its spray performance was also studied.The experimental tests and evaluation indicated the optimum working range is 0.3–0.7 MPa of wind pressure,1.2–10.2 L/min of water quantity,and 1.0–3.5 m of spraying distance.Moreover,this novel coating technology was tested in the Dashuitou Coal Mine in Gansu Province of China.Compared with conventional counterparts,the proposed new technology is safe,efficient,and convenient to operate.During spraying,dust concentrations were kept at less than 10 mg/m3,and the average rebound ratio resilient rate of solid materials was below 13%.After spraying,the average leakage every 100 m was 4 m3/min,and the oxygen volume fraction in the adjacent goaf was approximately 4%,demonstrating excellent air leakage prevention.

Design of hydrogen leakage detection and alarm processing system for the fuel cell power train lab

The hydrogen leakage detection and alarm processing system is established for the fuel cell （FC） power train lab to meet the hydrogen safety demand of the FC performance test and examination for the project named ＂Research and Development of the Vehicular Technology for the Fuel Cell City Bus＂ by Tsinghua University. The established hydrogen safety system includes the hydrogen supply system, hydrogen leakage detection system, alarm processing system, ventilation system, measures against electrostatic, thunder-arresting and explosion-protection, and the strict hydrogen operation rules. In this safety system, the explosion proof catalytic combustion sensors are used to detect the hydrogen leakage and the electrical control system is designed to process the alarm automatically. The hydrogen safety system plays an important role in the performance, examination of the FC and the assuring the personnel＇ s safety of the fuel cell power train lab.

连续热镀锌板漏镀原因分析及预防措施

对连续热镀锌板漏镀的原因进行分类分析,利用金相显微镜、扫描电镜及能谱仪精确确定漏镀的原因,并提出改进措施,提高了镀锌板的表面质量,减少了漏镀的发生。

渤海油田深井深层防漏堵漏技术策略研究

通过分析渤海油田近三年来漏失事件的漏失程度及类型,从工程角度提出渤海深井深层防漏技术策略和堵漏工艺选择策略,针对渤海深井深层漏失情况,从工程角度对漏失程度及类型进行统计分析,并结合现场情况和堵漏技术,提出渤海深井深层防漏技术和工艺选择策略,以提高钻前避漏的有效性和堵漏工艺的高效性,给海上油气田勘探开发提供一种安全、经济和高效新的思路。

北京地铁既有结构渗漏风险防控体系研究

针对北京市地下水位上升导致的地铁结构渗漏问题,如何科学合理地对北京地铁渗漏进行治理及防控成为当前研究的关键。从既有地铁结构渗漏风险识别、风险评价和风险应对策略3方面,对北京地铁既有结构渗漏风险防控技术体系进行系统研究与分析。首先,从风险识别入手,对引起渗漏病害的因素进行全方位分析;然后,在风险识别研究的基础上进行风险评价,将地铁渗漏病害按照定性和定量的方法对区间和车站结构进行分类分级,给出渗漏等级A、B、C和D,并提出应急及常规治漏措施;最后,提出相应的渗漏风险应对策略,包括应急处置和一般渗漏治理。研究内容以期为类似地铁结构病害治理体系提供理论参考和技术支撑。

一种防渗漏防过量加注的车载尿素加注与存储系统

为满足国六排放标准,需要在柴油车排气后处理系统上设计SCR系统。SCR系统通过实时监控排气上游NOx的含量来精准控制尿素的实时喷射量以达到净化尾气的目的,因此需要随车携带尿素。本文介绍了一种防渗漏防过量加注的车载尿素加注与存储系统,解决了车辆实际使用过程中出现的尿素箱变形,尿素渗漏,过量加注尿素至尿素箱内壁导致尿素箱内超声波液位传感器无信号的问题,对汽车工程技术人员具有很大的借鉴与参考意义。

神东矿区立体帷幕注浆精准堵漏风与高效防灭火技术

为高效治理神东矿区浅埋藏煤层开采漏风引起的煤自燃隐患,以大柳塔煤矿活鸡兔井12_上、12_下煤层工作面为研究对象,通过立体帷幕注浆的方式进行精准堵漏风与防灭火工程示范。首先利用地质剖面移动角计算注浆距离,并设计注浆平面布置,同时针对不同地质情况,设计了先导钻孔、注浆钻孔和监测钻孔;根据活鸡兔井实际情况,共施工104个钻孔,设计帷幕体长度约1020 m,高度约40 m;通过分段上行式注浆法,设计工作面切眼外侧注浆高度72 m,12_上205运输巷段注浆高度12 m,注浆宽度15 m,总注浆169569.1 m^(3)。通过立体帷幕注浆,12_下205工作面漏风较同条件下最大减少约1000 m^(3)/min,12_下207工作面漏风较同条件下最大减少近800m^(3)/min;堵漏风效果明显,有效降低12_下煤层工作面煤自燃隐患。

液氢槽车氢泄漏风险分析

运用风险管理系统工程原理,采用故障树分析法,对液氢槽车运行过程中的氢泄漏风险进行分析评估。分析了液氢槽车氢泄漏事故机理,明确基本事件32项和中间事件17项,建立了故障树模型。基于故障树的结构分析,求解最小割集,确定了各基本事件的结构重要度。基于专家经验判断的模糊方法预测基本事件概率,采用最小割集计算法近似计算氢泄漏顶事件的发生概率,并计算事件概率重要度,实现故障树的半定量分析,构建基于故障树的液氢槽车氢泄漏风险评价体系。基于事件的结构重要度和概率计算,确定了外力损坏罐体、外热损坏罐体、制止阀卡死、安全阀故障、外力损坏制止阀、泄压失效6项重要风险,并从运营单位日常定检、罐车防护装置设置、液氢储罐失效监测等方面提出了针对性的防范措施以降低液氢槽车氢泄漏风险。

大倾角工作面采空区均压-注氮联合防火数值模拟研究

以峻德煤矿93172大倾角外部漏风工作面为例,研究大倾角外部漏风采空区均压参数合理性以及对注氮防火的影响。采用Fluent数值模拟方法对采空区进行流场分析,充分考虑位压的影响,合理设置工作面和采空区进回风口及漏风口压力边界参数;建立了“L”形大倾角采空区冒落分布模型,进行采空区“恰当均压”,“欠均压”,“过均压”数值模拟,探究不同均压工况的采空区自燃三带分布,同时探讨了采空区均压注氮的合理参数选择。结果表明:“恰当均压”的采空区自然氧化带宽度最短;注氮防火应在“恰当均压”条件下进行,否则将会极大降低采空区惰化效果,徒增注氮量。研究结果对现场科学制定均压-注氮联合防火措施提供理论指导,同时压力边界参数设置方法为大倾角工作面采空区均压-注氮联合防火相关数值模拟研究提供科学参考。

冶金行业轧机液压油泄漏分析与治理

以山西太钢不锈钢股份公司硅钢事业部酸轧机组为案例,对冶金行业液压系统油品“跑冒滴漏”现象的原因进行详细分析,结合实际设备运维经验总结相应的防治措施并给出了新方案,对冶金行业从装备角度“降本增效”具有指导意义。

矿用有机增韧泡沫的制备及性能研究

为增强矿用高分子泡沫材料的韧性,添加有机材料聚乙二醇(PEG)对泡沫进行增韧效果改性。采用扫描电镜、热重实验、氧指数测试、锥形量热测试、抗压强度测试,发泡与固化时间测定研究了添加不同分子量PEG改性的作用效果。结果表明:不同分子量PEG能有效增加酚醛树脂泡沫的抗压强度,减小其粉化率,PEG分子量为1 000时,添加量为6%增韧效果最好,抗压强度达到0.155 MPa,粉化率降低到1.3%;添加一定量的PEG能有效增加酚醛树脂发泡倍数,但同时会增加其泡沫的收缩率与固化时间;PEG改性酚醛树脂泡沫孔径结构更加均匀,泡沫的孔径也更加均匀,这主要是由于未与酚醛树脂反应的PEG起到了表面活性剂的作用,能更好地使固化剂等与树脂混合;对于不同PEG分子量酚醛树脂泡沫的热稳定性,分子量越大,添加量越多的酚醛树脂泡沫其热稳定越差。

铁山坡高含硫气藏安全快速钻井技术优化与应用

针对铁山坡气藏硫化氢含量高(最高达222.30 g/m^(3))、嘉五以上地层倾角大(最大倾角25°)、须家河组研磨性强、嘉陵江组高压盐水侵、飞仙关组地层压力系数低等难题,开展了套管柱、井口装置、钻具抗硫材质优选,优化了铁山坡区块的井身结构,优选了高陡构造防斜提速工具,形成了铁山坡高含硫气藏安全快速钻井技术。现场应用效果表明,优选的抗硫钻具、套管柱、井口装置满足了高含硫气藏安全高效开发的要求;四开井身结构有效解决了上部地层井漏、垮塌、盐水侵的问题,降低了飞仙关高含硫层段的井控风险;优选了垂钻工具、钻头和旋导工具,铁山坡气田平均机械钻速由1.85 m/h提速到3.61 m/h,铁山坡6口井平均钻井周期缩短了16.11%。该研究成果为后续川东北高含硫气藏的安全快速钻井提供了技术支撑。

基于数据加密技术的计算机软件安全防护技术

为避免因安全防护不到位而出现数据泄露抗攻击性低等情况,该研究提出基于数据加密技术的计算机软件安全防护技术。在计算机软件运行过程中,为防止数据信息在传输和储存时被篡改,需要在生成数据信息密钥的基础上,构建数据加密模型。然后,将单授权中心改为多授权中心,在启动适当的安全启动功能后,为防止计算机软件数据信息在传输过程中发生泄露,对初始化函数进行防泄漏编码处理,以此来实现对计算机软件安全防护的整体设计。实验表明:相比于传统技术,基于数据加密技术的计算机软件安全防护技术的防泄漏功能更有优势。

麻地梁煤矿首采综放面收作期间防灭火技术研究

麻地梁煤矿507首采面是采用放顶方法开采埋藏浅特厚的长焰煤,漏风严重,丢煤多,尤其在工作面收作期间未进行放顶,采空区遗煤量更大。另外,工作面未采阶段推进速度慢,遗煤氧化时间长,极易引起采空区煤自然发火。针对以上情况,采取注氮降氧、高位钻孔注浆和注高固水材料覆盖隔氧、堵漏控风等的综合防灭火措施,保证了该工作面支架的安全撤出,为类似回采条件的工作面收作期间的防灭火提供参考。

页岩油上下地层漏失井控漏提速钻井技术

国内页岩油钻探技术趋于成熟,但钻探过程中依然存在钻井液漏失严重、机械钻速低和钻井周期长等问题,严重制约着页岩油开发的提速提效。通过分析青海页岩油前期6口井钻井数据,在明确了地层复杂情况和漏失特点基础上,将常规四开井身结构精简为二开,减少套管层序的同时实现固封漏失地层;根据漏失类型选择钻井液体系,通过改进BH-WEI钻井液关键处理剂配比,提高钻井液的稳定性、抑制性和封堵性,降低漏失量,实现有效预防漏失;同时,将螺杆钻具上下扶正器距离调整为12 m,降低滑动钻进比例;通过优化PDC钻头结构,水平段采用“高造斜率旋导ATC+低速直螺杆”定向工具等钻井技术,提高机械钻速,形成了青海页岩油控漏提速关键钻井技术。在青海页岩油区块的8口井应用了该技术,与前期钻探的6口井相比,平均单井漏失量由335.02 m^(3)降至21.08 m^(3),机械钻速由4.45 m/h提高至7.36 m/h,钻井周期由94.77 d缩短至68.26 d。现场应用结果表明,该技术可解决青海页岩油钻井技术难点,为青海页岩油资源的有效开发提供了技术支撑。

基于漏风“源汇”关系的采空区气体分布规律及漏风防治研究

针对浅埋煤层开采后地裂缝发育及开采动压条件下联巷密闭裂隙发育导致采空区气体重新分布问题。采用理论分析、数值模拟、现场试验的方式对“多源一汇”采空区气体分布规律及漏风防治进行了研究。以神东某煤矿为背景分析了漏风通道发育原因,基于SF6示踪气体漏风测试技术得到了采空区漏风“源汇”关系,数值模拟了该漏风“源汇”条件下采空区气体分布规律,给出了漏风防治措施。研究结果表明:漏风条件下采空区气体分布会发生较大变化,且其危险程度与漏风量大小有关,采用封堵技术可实现对其控制。