改良经脐单孔三通道腹腔镜精索静脉高位结扎术的临床应用

目的 探讨改良经脐单孔三通道腹腔镜精索静脉高位结扎术的可行性。方法 2011 年3 月至2013 年3 月对25例精索静脉曲张患者采用改良经脐单孔三通道腹腔镜精索静脉高位结扎术（A 组）,30 例精索静脉曲张患者采用传统三孔法腹腔镜下精索内静脉高位结扎术（B 组）,比较并分析两种术式的手术时间、术后住院时间、术后近期并发症、精液常规变化、术后美容效果等。结果 单侧及双侧手术时间A 组分别为（35.0±8.6）min 及（45.0±11.5）min, B组分别为（18.0±6.5）min 及（25.0±8.2）min,A 组长于B 组,差异有统计学意义（P＜0.05）。术后住院时间A 组为（2.1±0.3）d,B 组为（2.5±0.5）d,差异无统计学意义（P ＞0.05）。两组术后近期并发症发生率及精液改善率均无统计学差异（均P ＞0.05）。A 组手术美容效果优于B 组。结论 改良经脐单孔三通道腹腔镜精索静脉高位结扎术不需专用单孔多通道操作平台,手术操作简化,安全有效,术后腹壁不留瘢痕,值得临床推广。     

右半结肠癌完全结肠系膜切除术清扫肠系膜根部淋巴结效果观察

目的 探讨右半结肠癌行完全结肠系膜切除术（CME）清扫肠系膜根部淋巴结的临床疗效。方法 以2010年12月 至2012 年12 月行CME 的57 例右半结肠癌患者作为观察组,同期接受传统结肠癌根治术的99 例右半结肠癌患者作为对照组,对两组患者的淋巴结清扫数量、平均出血量、手术时间、住院时间、术后排气、排便时间、手术并发症、2年局部复发率及生存率等情况进行比较,初步评价CME 清扫肠系膜根部淋巴结的临床效果。结果 CME 组与对照组总淋巴结清扫数量分别为（22.6±2.8）、（14.6±2.7）枚,CME 组淋巴结清扫数量明显多于对照组（P＜0.05）;CME 组平均出血量为（167.4±20.8）ml,对照组为（205.4±19.3）ml,CME 组出血量少于对照组（P＜0.05）;两组的手术时间、住院时间、术后排气、排便时间比较差异均无统计学意义（均P＞0.05）;CME 组手术并发症发生率与对照组比较差异无统计学意义（P ＞0.05）;Ⅲ期患者CME 组2 年局部复发率38.2％、生存率88.2％,对照组分别为64.8％和68.5％,两组差异有统计学意义（均P＜0.05）。结论 右半结肠癌患者采用CME 清扫肠系膜根部 淋巴结是安全和有效的。     

PTGD 与腹腔镜胆囊切除序贯微创治疗高危急性胆囊炎疗效分析

目的 探讨经皮经肝胆囊穿刺引流术（PTGD）与腹腔镜胆囊切除（LC）序贯微创治疗高危急性胆囊炎（AC）的疗效。方法 对76 例高危AC患者根据就诊时患者全身状况、心肺功能及胆囊B 超检查结果,分别采用PTGD 加延期LC 治疗（36 例,为PTGD 组）及同期直接LC 治疗（40 例,为Non-PTGD 组）,观察并比较两组患者LC 手术时间、术中失血量、中转开腹率、术后并发症发生率及住院时间。结果 PTGD 组手术时间、住院时间均明显短于Non-PTGD 组（t =1.96、1.84,均P＜0.05）;PTGD 组术中失血量明显少于Non-PTGD 组（t =2.03,P＜0.05）;PTGD 组中转开腹率、术后并发症发生率均明显低于Non-PTGD 组（字2 =6.74、6.97,P＜0.05）。结论 PTGD 与LC 序贯微创治疗高危AC 疗效确切、安全,值得临床推广。     

完全腹腔镜胰十二指肠切除术6例临床疗效分析

目的 评估完全腹腔镜胰十二指肠切除术（laparoscopic pancreaticoduodenectomy,LPD）的可行性、安全性。方 法 采用LPD 治疗胰头或十二指肠肿瘤患者6 例,回顾性分析手术时间、术中出血量、淋巴结清扫数目、术后肛门排气时间、术后住院天数、手术并发症发生率及术后短期疗效。结果 6 例手术均在完全腹腔镜下完成,无中转开腹病例。手术时间（380.5±38.1）min;出血量（241.7±189.3）ml;清扫淋巴结（15.3±2.8）枚;平均肛门排气时间（3.5±1.0）d;术后住院（14.0±5.7）d。手术并发症发生率为33.3％（2/6）,其中轻度胰漏1例,肺炎1例;本组患者术后随访3~12个月,无肿瘤复发及转移。结论 LPD 安全、可行,能达到胰头或十二指肠肿瘤根治性切除的目的。     

早期肠内营养在胃癌根治术后的应用分析

目的 探讨术后早期肠内营养（EN）在胃癌患者中应用的安全性和可行性。方法 将78 例接受胃癌根治术的患者 随机分为两组,其中EN 组40 例,全肠外营养（TPN）组38例。比较两组患者营养状况变化、肠功能恢复情况、术后并发症发生情况、营养费用和住院时间等。结果 术后第7天,EN 组患者总淋巴细胞计数（TLC）为（1.74±0.25）×109/L,明显高于TPN 组的TLC（1.59±0.28）×109/L（P＜0.05）,其他营养指标两组间比较均无统计学差异（均P＞0.05）;EN 组患者肠功能恢复较TPN 组快,营养费用和住院时间较TPN 组少,均有统计学差异（均P＜0.05）;EN 组与TPN 组术后并发症的发生率分别为12.50%和18.42%,比较无统计学差异（P＞0.05）。结论 术后早期EN 可促进肠道功能的恢复,有效改善患者营养状态,降低住院费用。     

腹腔镜下全子宫切除术术后并发症发生的相关因素分析

目的 探讨腹腔镜下全子宫切除术患者术后并发症发生的相关因素。方法 回顾性分析106 例腹腔镜下全子宫切除术患者的临床资料。结果 106 例患者术后并发症发生率为14.15%,发生率最高的是皮下气肿（3.77%）,其次是残端感染（2.88%）、盆腔包裹性积液（2.88%）,盆腔手术史（P =0.037）、术前贫血（P =0.03）、子宫＞孕12 周大小（P =0.022）、手术时间＞120min（P =0.033）、手术出血量＞100ml（P =0.013）为术后并发症发生的危险因素,其中术前贫血（OR=9.939,P =0.048）、手术时间＞120min（OR=6.120,P =0.038）为术后并发症发生的独立危险因素。结论 术前贫血、手术时间＞120min为患者术后并发症发生的独立危险因素。     

远端胃大部分切除术后消化道重建术式的对比研究

目的 对比远端胃大部分切除术后行连续性空肠间置术与BillrothⅠ式及Roux-en-Y 式吻合术的临床效果。方法 回顾性分析2012 年1 月至2013 年6 月接受手术的远端胃癌患者95 例,按不同消化道重建方式分为3 组。A 组30 例患者行连续性空肠间置术,B 组32 例行BillrothⅠ式吻合术,C 组33 例行Roux-en-Y 式吻合术。比较3 组患者术前预后营养指数（PNI）、手术时间、术后6个月及1 年并发症发生率、进食量、血浆白蛋白水平、体重及Visick 分级指数。结果 3 组患者术前PNI均无统计学差异（均P＞0.05）。A 组患者手术时间与B 组无明显差异,且均明显少于C 组的手术时间（均P＜0.05）。术后6 个月及术后1 年3 组患者的进食量、体重及营养状况的恢复均无统计学差异（均P＞0.05）。A 组患者术后腹胀情况明显少于C 组（P＜0.05）,胆汁反流性胃炎明显少于B 组（P＜0.05）。结论 胃大部分切除术后连续性空肠间置,安全有效,与传统的BillrothⅠ式及Roux-en-Y 式吻合术比较,可缩短手术时间,更快的恢复患者的消化功能,维持消化道正常通路,防止胆汁反流,将有可能成为消化道重建的主要方式之一。     

输尿管导管在非复杂性输尿管中下段结石输尿管镜碎石术后的应用

目的探讨输尿管导管在非复杂性输尿管结石行输尿管镜下碎石术后的临床应用价值.方法选取行输尿管镜钬激光碎石术的非复杂性输尿管结石患者98例,其中术后放置输尿管导管49例(导管组),放置双J管49例(双J管组).比较两组患者碎石术时间,以及术后留管期间(取管前)尿路刺激症、血尿、尿路感染、腰痛或侧腹痛等并发症的发生情况.结果导管组手术时间显著短于双J管组(P<0.01).两组患者仅术后第4天尿路刺激症发生率的差异有统计学意义(P<0.05),其他并发症发生率的差异均无统计学意义(均P>0.05).术后1个月检查结果显示两组患者无石率均为100%,术后3个月检查结果显示均无输尿管狭窄发生.结论输尿管导管是输尿管镜治疗非复杂性输尿管结石术后引流的一种好方法.     

外源性建立褪黑素节律对老年腹腔镜直肠癌手术患者快速康复的影响

@@快速康复外科（fast track surgery,FTS）对传统手术围术期的治疗方法进行改进,可以减少患者的不适感、降低患者术后应激反应及并发症发生率、促进康复、缩短住院时间[1]。老年患者存在各器官功能的衰退,睡眠质量下降,常影响术后康复训练和身体功能的恢复[2]。褪黑素（melatonin）是调控机体生物节律的内分泌激素之一,主要参与人的昼夜节律和诱导睡眠的调控[3]。同时有研究发现,褪黑素亦参与了机体进食和肠道功能的调节[4]。本文拟评价人工建立褪黑素节律对老年腹腔镜直肠癌手术患者快速康复的影响。     

全胸腔镜手术与胸腔镜辅助小切口手术对Ⅰ期非小细胞肺癌的临床疗效比较

目的比较全胸腔镜手术与胸腔镜辅助小切口手术对Ⅰ期非小细胞肺癌的临床疗效。方法选择86例Ⅰ期非小细胞肺癌患者,按随机数字表法分为使用全胸腔镜手术治疗组（全胸腔镜组46例,采用3孔法）及使用胸腔镜辅助小切口手术治疗组（胸腔镜辅助组40例,采用2孔法）。比较两组患者一般手术情况、术后生存质量及无瘤生存情况。结果两组患者的手术时间、术中出血量、术后带胸管时间及住院时间比较差异均无统计学意义（均P＞0.05）,全胸腔镜组患者术后胸腔液引流量[（217.8±50.5）ml]和视觉模拟评分（VAS）[（3.9±0.6）分]均低于胸腔镜辅助组[（258.0±48.6）ml、（6.5±1.2）分],差异均有统计学意义（t=3.75、12.96,均P＜0.05）。全胸腔镜组患者术后生存质量评分[总分（88.7±9.6）分]高于胸腔镜辅助组[总分（71.1±8.2）分],差异有统计学意义（t=9.1,P＜0.05）。两组患者术后无瘤生存时间比较差异无统计学意义（P＞0.05）。结论全胸腔镜手术治疗Ⅰ期非小细胞肺癌的近、远期疗效均较好,值得推广应用。     

On access to temporary resources

The shareable resources of a multiprogramming system can be classified as either permanent or temporary, and their use can be classified as either exclusive or non-exclusive. While semaphores, as defined by Dijkstra synchronize access to permanent resources, this article proposes two new primitives for synchronizing access to temporary resources. Their usefulness is demonstrated by examining the problem of a number of concurrent «readers» and »writers« sharing a single file. Finally, a high-level language notation is proposed which synchronizes access to a declared, shareable resource of any of the categories classified above.     

Remote access laboratories in applied mathematics

The cutting edge knowledge in the art of mathematical technology is located in dispersed nodes, research groups on applied mathematics, mathematical physics, scientific computing etc. The work often leads to development of software representing state-of-the-art methods in the field. These environments are often experimental, under revisions, near the laboratory floor of on-going research. This stage sometimes precedes the later development to actual products and commercialization. Web-technologies are a viable media for innovative processes and knowledge transfer. In this article I draw attention to the possibility of creating added value for the knowledge repository of applied mathematics and computational methods via remote access software sharing. I present examples and refer to the obvious potential of this approach in the modern era of grid computing. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Spatial encryption supporting non-monotone access structure

We investigate a variant of spatial encryption (SE) we call ciphertext-policy SE (CP-SE), which combines the properties of SE and those from ciphertext-policy attribute-based encryption (CP-ABE). The resulting primitive supports non-monotone access structure. In CP-SE, the decryptability of a ciphertext depends on whether or not the required attribute vectors are in the same affine space that also corresponds to the decryption key. This gives rise to many new applications, for example, SE supporting negation, hierarchical ABE and forward-secure ABE. In this paper, we present techniques for generic construction of CP-SE from ciphertext-policy inner product encryption (CP-IPE). Our techniques are property-preserving in the sense that if the CP-IPE scheme from which we derive our CP-SE scheme is fully secure, for example, then so is the resulting CP-SE scheme. Moreover, interestingly, we show that it is possible to perform transformation of the opposite direction, that is, how to construct a CP-IPE scheme given a CP-SE scheme.     

A stochastic recirculation system with random access

A model for a stochastic recirculation system with randomly accessed multiple heterogeneous servers, no waiting rooms, and exponentially-distributed service times is provided. In this system the units are assigned to one of the servers upon arrival by random mechanism. Units which find all servers busy recirculate and combine with the incoming arrivals and join those already in the system to initiate the next cycle. The equilibrium behavior of the internal and external stochastic processes of the system is analyzed using a two parameter approximation. A simulation model is also developed and its behavior is compared against the analytical model at the steady state. The model with randomly-accessed servers is compared to a single server model already established in the literature. The performance of the model is then examined for a wide range of parameter values to obtain conclusions about its optimal performances.     

A space efficient direct access data structure

Given a file T, we suggest a data structure based on pruning a Huffman shaped Wavelet tree (WT) according to the underlying skeleton Huffman tree that enables direct access to the i-th element of T. This pruned WT is especially designed to support faster random access and save memory storage, at the price of less effective rank and select operations, as compared to the original Huffman shaped WT. The savings are significant only if the underlying alphabet is large enough. We give empirical evidence that when memory storage is of main concern, our suggested data structure generally outperforms other direct access techniques such as those due to Külekci, dacs and sampling, with a slowdown as compared to dacs and fixed length encoding.     

Faster deterministic wakeup in multiple access channels

We consider the fundamental problem of waking up n processors sharing a multiple access channel. We assume the weakest model of synchronization, the locally synchronous model, in which no global clock is available: processors have local clocks ticking at the same rate, but each clock starts counting the rounds in the round in which the correspondent processor wakes up. Moreover, the number n of processors is not known to the processors. We propose a new deterministic algorithm for this problem in time O(n³log³n), which improves on the currently best upper bound of O(n⁴log⁵n).     

On file structuring for non-uniform access frequencies

An important property of file structures is their behavior when the underlying distribution of access frequencies is non-uniform. In this note we consider methods for structuring files so that initially unknown but non-uniform access frequencies are exploited in a way that reduces mean search times. As a specific illustration a simple algorithm is applied to sequence search trees and shown to produce structures with mean search times that are significantly less than those produced by an algorithm creating tree structures independent of access frequencies. An analytic result is obtained for this improvement when access frequencies are uniform. Samples from the results of Monte Carlo simulations are used to illustrate this improvement when access frequencies are non-uniform.     

Probability models for access security system architectures

This paper presents probability models of access control security system architectures. Access control is the process of screening objects; for example people, baggage, entering a secured area in order to detect and prevent entry by threats such as unauthorized personnel, firearms, explosives. A security system architecture consists of device technologies, as well as operational policies and procedures for utilizing the technologies. The probability models are developed based on Type I (a false alarm is given) and Type II (a threat is not detected) errors. The concept of controlled sampling, in which objects may take different paths through the system, is introduced. New architectures consisting of multiple devices and controlled sampling are proposed and analyzed. The results presented indicate that for specific threat levels, multiple-device systems can be identified which outperform single-device systems for certain error probability measures.     

The density based access method: A novel approach to optimizing run-time throughput for IEEE 802.11 DCF access control

According to previous work, the performance of the Distributed Coordination Function (DCF) (i.e., the basic access method of the IEEE 802.11 protocol) is far from optimum due to use of the binary exponential backoff (BEB) scheme as its collision avoidance mechanism. There has been considerable discussion of DCF issues and its performance analysis. However, most schemes assume an ideal channel, which is contrary to realistic wireless environments. In this paper, we present a simple yet pragmatic distributed algorithm, designated the density based access method (DBM), which allows stations to dynamically optimize the network throughput based on run-time measurements of the channel status. Our simulation results demonstrate that the DBM is highly accurate. The performance in terms of throughput and fairness is nearly optimal by use of the proposed scheme.