摘要：近年来由于计算机技术在结构优化中的应用得到飞速发展,设计者可以轻松得到优化程度很高的结构设计.但是从结构的极限安全角度来看,这样的优化分析很容易导致结构缺少冗余度.与通常的框架结构不同,空间结构能够在使用少量材料的情况下得到无柱大空间.这样的结构通常会被设计为主要通过构件轴力来抵抗设计荷载,而结构整体则容易表现为脆性行为并趋向于发生脆性破坏.由于主要是通过构件内弯矩来抵抗外荷载,框架结构则趋向于发生韧性破坏.因此我们应当集中更多的注意力到有效率的大型空间结构设计上.对于评价结构是否高效,结构冗余度是一个非常重要的概念,然而很难对此概念本身作出定量评估,而其中结构最大承载力可以作为评价结构冗余度的一个依据.本文将给出一个简单的计算方法(Compact procedure Method)来获得空间结构的极限荷载系数.这个方法基于线性规划法,不需要进行复杂的弹塑性分析便可获得结构的最大荷载系数.通过数值分析与传统的结构分析方法相比,该方法的正确性和有效性得到了验证.

摘要：Background: procedure for prolapse and hemorrhoids (PPH) has emerged as an alternative surgical treatment of symptomatic hemorrhoids. The operative technique along with the device to be used is constantly evolving. Aim: The aim of the present study was to evaluate results of PPH using a modified technique and an innovative circular stapler. Material and Methods: A prospective, comparative study of patients undergoing PPH for symptomatic Grade II and Grade III internal hemorrhoids with either 32 mm or 34 mm stapler diameter (Circular Stapler for Hemorrhoids-CSH 32/34) during a 36 month period (1/1/2012-1/1/2015) was performed. A modified operative technique using two purse string sutures was employed. Patients were evaluated and compared in terms of postoperative complications, operation time, length of hospital stay and time to return to normal activities. Results: A total of 100 patients were included: 50 in the CSH 32 group and 50 in the CSH 34 group. Complication rates were equal for both stapler diameters (32 mm and 34 mm). Serious or life threatening complications were not encountered and need for reintervention was never met. Operation time, length of hospital stay and time to return to normal activities were similar in both groups. Conclusions: Our study suggests that there are no significant differences between the two available diameters of a new-fangled circular stapler, using a modified technique. It seems that progress of hemorrhoidal staplers has led to a step towards the goals of implement and from then on complications of surgical practice could be merely a matter of operative technique.

摘要：The paper illustrates a further new way of using the CARSO procedure for response surfaces analyses derived from experimental designs based on Double Circulant Matrices (DCMs). We report a case study regarding a design based on a mixture of three chemicals plus an evaporating solvent, in order to compare the relative reliability of designs based either on 3 only or on all 4 factors. We show that both designs give the same results, but the second is preferable because it represents the real situation at the beginning of the process, so that it is possible to know the required amount of solvent that should be used for each experiment. Obviously this applies to any number of factors using the correspondent DCM.

摘要：AIM:To investigate a newly designed stent and its dilatation effect in a rabbit model of benign esophageal ***:Thirty-four New Zealand white rabbits underwent a corrosive injury in the middle esophagus for esophageal stricture *** rabbits with a successful formation of esophageal strictures were randomly allocated into two *** control group(n = 15) was implanted with a conventional stent,and the study group(n= 15) was implanted with a detachable "pieced" *** study stent(30 mm in length,10 mm in diameter) was composed of three covered metallic pieces connected by surgical suture *** stent was collapsed by pulling the suture lines out of the *** weeks after stricture formation,endoscopic placement of a conventional stent or the new stent was *** extraction was carried out four weeks *** extraction rate,ease of extraction,migration,complications,and survival were ***:Stent migration occurred in 3/15(20%)animals in the control group and 2/15(13%) animals in the study group;the difference between the two groups was not statistically *** the end of four weeks,the remaining stents were successfully extracted with the endoscope in 100%(11/11) of the animals in the study group,and 60%(6/10)of the animals in the control group;this difference was statistically significant(P < 0.05).There was no difference in the mean number of follow-up days between the control and study groups(25.33 vs25.85).Minor bleeding was reported in five cases in the study group and four in the control *** were no severe complications directly associated with stent implantation or extraction in either of the two ***:In this experimental protocol of benign esophageal strictures,the novel "pieced" stent demonstrated a superior removal rate with a similar migration rate compared to a conventional stent.

摘要：自从Stephens^(1)确立耻骨直肠肌在控制排便中的作用之后,许多作者^(2～4)设计出旨在替代耻骨直肠肌的手术方法,以治疗直肠肛门发育不全术后并发的肛门失禁.1978年Hakelius首先应用自体掌长肌游离移植耻骨直肠肌成形术治疗小儿肛门失禁获得成功^(4).