Study on Machining Properties of Eucalyptus urophylla× E.grandis:Ⅱ.Shaping,Boring,Mortising and Turning

The research method of this paper is based on the standards of American Society for Testing and Materials (ASTM). Four items that contain boring, mortising, shaping and turning are selected to study the machining properties of E. urophylla × E. grandis plantation wood. The reasons for machining defects are analyzed. The resultshows thatE. urophylla × E. grandis planted in South China isa good specieswith great potential for solid wood utilization.

Corona Mortis血管解剖学研究及其临床意义

目的:探讨闭孔血管和髂外血管在腹股沟区的分支,为减少髂腹股沟入路术中出血提供解剖学基础。方法:对25具新鲜中国成人尸体标本共50侧半骨盆进行解剖学研究,观测闭孔血管和髂外血管在腹股沟区的分支及其吻合支(CoronaMortis血管)的大小、出现率、吻合血管行径和吻合血管至耻骨联合的距离。结果:72%(36侧)耻骨上支表面至少存在1条血管吻合支,其中28%(14侧)存在2条或3条血管吻合支,24%(12侧)同时存在动脉吻合支和静脉吻合支。耻骨上支表面的血管吻合支平均直径2.6mm(2.0～4.2mm)。血管吻合支紧贴耻骨上支或髂耻隆起,几乎垂直地下行于髋臼窝壁或耻骨支后方,经闭膜管出盆腔,血管吻合支与耻骨联合的平均距离52mm(38～68mm)。在此区域手术以及髋臼或骨盆前环骨折极易损伤CoronaMortis血管。结论:闭孔血管和髂外血管的吻合支较粗,出现率高,位于耻骨上支表面。髂腹股沟手术入路应特别注意CoronaMortis血管的存在。

Strength performance of mortise and loose-tenon furniture joints under uniaxial bending moment

We determined the effects of adhesive type and loose tenon dimensions （length and thickness） on bending strength of T-shaped mor- tise and loose-tenon joints. Polyvinyl acetate （PVAc） and two-component polyurethane （PU） adhesives were used to construct joint specimens. The bending moment capacity of joints increased significantly with increased length and thickness of the loose tenon. Bending moment capacity of joints constructed with PU adhesive was approximately 13% higher than for joints constructed with PVAc adhesive. We developed a predictive equation as a function of adhesive type and loose tenon dimensions to estimate the strength of the joints constructed of oriental beech （Fagus orientalis L.） under uniaxial bending load.

Reliability-Based Shape Optimization of Tenon/Mortise in Aero-engines with Contact

Based on the theory of reliability-based structural shape optimization, exact expressions of the sensibility using the stochastic finite element method for contact problems were derived in detail, and the basic steps of structural optimization were given. A coattail-type tenon/mortise of an aero-engine was optimized. In this model, the maximum equivalent stress of the nodes on the boundary of the tenon was the objective function; the width of tooth’s neck and the side surface’s slope angle of a tenon were design variables, with constraints of tension stress, extrusion stress and reliability index. The result showed that the distributions of the contact pressure between tenon and mortise, the equivalence stress and reliability index were more reasonable. It validates the correctness of the optimization model and the reliability-based structural shape optimization, and provides valuable references for structural design of the tenon/mortise.

Finite element analysis of stress and strain distributions in mortise and loose tenon furniture joints

We studied the effect of loose tenon dimensions on stress and strain distributions in T-shaped mortise and loose tenon （M＆amp;LT） furni-ture joints under uniaxial bending loads, and determined the effects of loose tenon length （30, 45, 60, and 90 mm） and loose tenon thickness （6 and 8 mm） on bending moment capacity of M＆amp;LT joints constructed with polyvinyl acetate （PVAc） adhesive. Stress and strain distributions in joint elements were then estimated for each joint using ANSYS finite element （FE） software. The bending moment capacity of joints increased significantly with thickness and length of the tenon. Based on the FE analysis results, under uniaxial bending, the highest shear stress values were obtained in the middle parts of the tenon, while the highest shear elastic strain values were estimated in glue lines between the tenon sur-faces and walls of the mortise. Shear stress and shear elastic strain values in joint elements generally increased with tenon dimensions and corre-sponding bending moment capacities. There was consistency between predicted maximum shear stress values and failure modes of the joints.

MORPHOLOGICAL CHANGES OF RATS MUSCLES AT VARIOUS POSTMORTEM INTERVALS BY SCANNING ELECTRON MICROSCOPY

The aim of this study was to observe the morphological changes of muscle in the process of rigor mortis. The quadriceps of 40 rats at various postmortem intervals were observed under the scanning electron microscope(SEM) and the light microscope by phosphotungstic acid haematoxylin(PTAH) stain. The results showed that the striations of muscle were blurred within 4 h, but they became apparent from 6 h to 24 h after death. The authors suggest that this phenomenon be associated with the increased resistance of muscle against the postmortal changes. The observations by scanning electron microscopy and light microscopy have revealed that the muscles do contract in the process of rigor mortis because the distance between two Z lines shortens and the I band narrows, compared with those in anaesthetised animals. The basic biochemical process for the formation of rigor mortis is the same as that of muscle contraction except that the former happens postmortem and the latter antemortem.

Anatomical and Clinical Implication of Corona Mortis in the Anterior Approaches of Pelvis in Sudanese Patient

Background: Corona Mortis is an abnormal blood vessels connecting Between obturator and external iliac systems of vessels and inferior epigastric vessels. It is located behind the superior public ramus at a variable distance from the symphysis pubis. Orthopaedic surgeons and obestitrtion found these vessels in the field of surgery. So displaced fractures or iatrogenic injury, can cause life threatening bleeding and hence these vascular anomalies are referred to us crown of death. The bulk of the studies about the corona mortise were conducted in the cadavers or 3D CT angiography and there was no studies were conducted about corona mortise in Sudan. The purpose of this study was to study the corona mortis anatomical and clinical implication in the anterior approaches to the pelvis and acetabulum in Sudanese patient. Methodology: Hospital based descriptive cross-sectional study was conducted among patients sustaining anterior pelvic anterior acetabulum fracture and underwent open reduction internal fixation by reconstruction plates. This study was conducted in Bahri Teaching Hospital from June 2017 to June 2018. Through the most common anterior approaches to the pelvis and acetabulum (Stoppa-modified stoppa-ilioinguinal), done by single surgeon and fulfil data sheet intra-operatively. Results: In a total of 30 pelvic halves corona mortis was detected in 13 patients (43%).The Majority in the Rt.hemipelvies 7 (53.8%) specimens: arterial 4/13 (30.8%), venous 1/13 (7.7%) and both arterial and venous in 8/13 (61.5%) specimens respectively. Of these (53.9%) had a large Diameter > 5 mm and the largest one measure 80 mm, with mean distance From the symphysis 5.8 + 1.6 mm. Conclusion: Only 13 patients have corona mortis, 12 of them were arterial with diameter more than 5 mm (53%), and thus surgeon should exercise caution during Surgery and secure its site to help minimizing surgery time, Clear surgical field and prevent iatrgenic injury.

国人corona mortis血管的应用解剖研究

目的观察corona mortis血管发生率及其毗邻关系,为经腹股沟入路手术提供解剖学基础。方法 2011年11月至2012年2月重庆医科大学附属第一医院血管外科共解剖经甲醛固定的正常成人尸体标本51具(男37具、女14具),均进行双侧解剖,共102侧,观察corona mortis血管与髂外血管系统之间的关系,并测量corona mortis血管外缘到耻骨联合的距离。结果在51例(102侧)标本中,有39例(66侧)标本至少存在1条或1条以上的吻合支,发生率为76.5%(39/51);该血管均跨过耻骨上支表面后向内下方向进入闭孔内,corona mortis血管至耻骨联合的平均距离:男性为(52.00±12.29)mm,女性为(55.39±11.86)mm。两侧corona mortis血管发生率以及到耻骨联合的距离差异均无统计学意义(P>0.05),男女发生率以及到耻骨联合距离差异均无统计学意义(P>0.05)。结论 corona mortis血管出现率高,发生率为76.5%,行径均跨越耻骨上支表面,在涉及到腹股沟入路手术时应注意其存在。

广藿香醇对东莨菪碱致记忆障碍小鼠学习记忆功能的影响

目的研究广藿香醇对东莨菪碱所致获得性学习记忆障碍小鼠学习记忆功能的影响。方法采用Morris水迷宫检测小鼠学习记忆能力,广藿香醇(80、40、20mg/kg)连续预防给药10d,训练前15minip给予东莨菪碱(1.5mg/kg)。行为学测试完成后,脑匀浆检测乙酰胆碱脂酶(AchE),丁酰胆碱脂酶(BuchE)以及胆碱乙酰转移酶(Chat)活性,免疫组化检测脑M1受体水平。结果与模型组相比,广藿香醇(80、40mg/kg)组小鼠学习记忆能力显著增强,脑AchE活性显著下降,而Chat活性显著提高,脑内M1受体水平也显著提高。结论广藿香醇具有促进东莨菪碱小鼠学习记忆的作用,该作用可能与其抑制脑内AchE活性,提高Chat活性和M1受体水平有关。

256排CT检查与Mimics软件结合在骨盆骨折临床应用的初步研究

目的探讨采用256排CT机行CT血管造影术(CTA)检查与Mimics软件结合在骨盆骨折中的临床应用。方法收集2014年4月至2014年12月于影像中心行双下肢CTA检查(L3至下肢踝关节)的31例(男性17例,女性14例)患者,共62个半骨盆的CTA原始数据。对CTA原始数据进行三维重建,并在三维重建模型上观察Corona mortis动脉并测量Corona mortis动脉的位置,记录结果。结果重建后的盆腔三维动脉血管图像可以比较完整地显示光滑的盆腔动脉系统。按照半骨盆计算法,62个半骨盆中发现13条Corona mortis动脉,总存在率为20.97%。左右两侧的半骨盆存在率分别是:19.35%(6/31)和22.58%(7/31),两者比较差异无统计学意义(P>0.05)。男性与女性半骨盆的存在率分别是:20.59%(7/34)和21.43%(6/28),两者比较差异无统计学意义(P>0.05)。按照整个骨盆计算法,31个骨盆中发现男性与女性Corona mortis动脉的存在率分别是:23.53%(4/17)和21.43%(3/14),两者比较差异无统计学意义(P>0.05)。结论 Mimics软件处理后的骨盆CTA三维重建可以清晰地、立体地观察到Corona mortis动脉的分布以及其走行,建议在骨盆髋臼手术之前应先行下肢CTA检查,然后进行三维重建,以明确Corona mortis动脉的存在及位置,避免术中伤及该血管。

CT血管造影结合三维重建技术对Corona Mortis动脉的解剖学研究

目的探讨Corona Mortis(CMOR)动脉的发生率、起源、走行及位置,为骨盆前入路手术提供依据。方法回顾性研究。收集2018年6月—2020年6月行CT血管造影检查的112例患者(224侧半骨盆)的影像资料,其中男68例、女44例,年龄28~92岁。将患者的CT血管造影影像资料进行三维重建,观察CMOR动脉的发生率、起源及走行情况,比较该动脉在男性与女性、左侧与右侧半骨盆发生率是否有差异,测量该动脉直径、与耻骨上支上缘最短距离以及与耻骨联合上缘中点距离,计算该动脉到耻骨联合所在矢状面的垂直距离与同侧髂前上棘到该矢状面垂直距离的比值。结果224侧半骨盆中,共发现40条CMOR动脉,发生率17.86%(40/224);男、女发生率分别为19.12%(26/136)、15.91%(14/88),左、右侧发生率分别为16.07%(18/112)、19.64%(22/112);差异均无统计学意义(χ^(2)=0.375、0.487,P值均>0.05)。CMOR动脉直径为(2.01±0.34)mm;该动脉与耻骨上支上缘最短距离为(3.41±1.22)mm;与耻骨联合上缘中点距离为(58.34±6.42)mm,男性(55.15±3.25)mm、女性(64.26±6.69)mm,性别间差异有统计学意义(t=4.643,P<0.01);该动脉到耻骨联合所在矢状面的垂直距离与同侧髂前上棘到该矢状垂直距离的比值为0.38±0.04,男性0.36±0.03、女性0.42±0.04,性别间差异有统计学意义(t=4.897,P<0.01)。结论三维重建技术可以清晰、准确地构建出CMOR动脉的三维模型,并对其相关解剖学参数进行精确测量,有助于术前制定个性化手术方案,指导术中入路,降低损伤CMOR动脉的风险。

Investigation on experimental load spectrum for high and low cycle combined fatigue test

As the outfield load spectrum is so complicated that it cannot be used directly for test study in laboratory.This paper presents a method to determine load spectrum for high and low cycle combined fatigue of turbine mortise at elevated temperature through experimental and numerical method.First of all,the low cycle load spectrum with duration time is determined through cumulative damage rule.The rain flow counting method is applied to obtain main cycles and sub cycles,and then the stress cycle is converted into pulsation cycle(stress ratio=0)based on the S-N curve and the Goodman curve;Secondly,three groups of different amplitudes tests are established to determine the high cycle amplitude.Finally,another three groups of the high-low combined cycle fatigue(HLCCF)tests for turbine mortise of a certain type engine are carried out.The results show that the macro and micro failure modes are identical with outfield's,which verifies the accuracy of the conversion method.

The importance of post-mortem examinations in cetacean biology:A report of a necropsy on Stenella coeruleoalba(Meyen,1833)(Cetacea:Delphinidae),from the Azores,Northeastern Atlantic

This article reports the necropsy of a specimen of striped dolphin Stenella coeruleoalba found stranded in the north coast of Terceira Island,Azores,Portugal.Here,the importance of standard protocols in post-mortem examinations and the need to adequately proceed were discussed.Stranded marine mammals are valuable specimens for several studies of pathology and other veterinary medical aspects.Although the causa mortis was not determined,the full access to stranded specimens was crucial,not only for pathology studies but also for a proper training to veterinary medicine students whenever possible.