A dorsal approach for the removal of the nasal septum in the horse

OBJECTIVE: To describe and evaluate a technique involving a dorsal approach for the removal of the nasal septum in adult horses. STUDY DESIGN: Retrospective clinical study. ANIMALS: Four client-owned horses. METHODS: Access for partial nasal septum resection was through a dorsal nasal bone flap. Septum resection was performed because of reduced airflow from septal deviation and/or thickening caused by traumatic insult or neoplasia. Preoperative clinical signs and diagnostic results were recorded. Intra- and postoperative complications were noted and follow-up information was obtained from telephone interviews of owners or by clinical examination. RESULTS: The abnormal segment of the nasal septum was completely removed in all horses. A dorsal nasal bone flap approach provided excellent access to the septum and allowed immediate control of hemorrhage; blood transfusion was not needed. Cosmetic results were considered good to excellent by owners and horses returned to their previous level of work without perceived limitations associated with airway function. CONCLUSIONS: Nasal septum resection by the dorsal approach permits good observation of the abnormal septum, and provides exposure that facilitates removal of nasal masses and reduction of depression fractures with minimal complications. CLINICAL RELEVANCE: A dorsal nasal bone flap approach should be considered for horses that require nasal septum resection because it can be achieved with minimal hemorrhage, good cosmetic results, and return to function.     

马传染性贫血病毒疫苗致弱过程中不同代次毒株LTR序列变异

有研究认为病毒基因组长末端重复序列LTR与病毒的毒力和复制能力直接相关.中国马传染性贫血弱毒疫苗是由一株高致病力毒株经体外白细胞传代而致弱的疫苗.经过体外超过110代传代后,病毒丧失了对马高致死性毒力并保持了良好的免疫原性.本文对传代过程中的不同代次病毒基因LTR进行了克隆和序列测定,发现传代过程中LTR发生了一系列明确的变异,一是转录起始位点在64代之前均以GGAC为特征,64代之后则表现为不规律的GAAC,AAAC,AGAC或GGTC;二是TAR起始碱基在59代之前多数为A,而64代之后均为G;三是在45代之后(55代除外),poly(A)附加位点一致表现为AA,这种一致的核苷酸变化均发生在毒力明显降低的代次,提示这些突变引起的位点或结构变化很可能与病毒毒力减弱有直接关系.     

COMMUNICATIONS OF NORMAL NASAL AND PARANASAL CAVITIES IN COMPUTED TOMOGRAPHY OF HORSES

Heads from 15 male and female horses of various breeds and ages were examined with computed tomography under general anesthesia in dorsal recumbency. The main interest was the evaluation of the entire paranasal sinus system. Special attention was paid to the location, size, and shape of the conchomaxillary, nasomaxillary, frontomaxillary, and sphenopalatinal openings. The frontomaxillary opening was the largest aperture and was found to be age-dependent in size mostly. Orientation and shape of the openings were sagittal or horizontal; the narrowest of them was the slit-like nasomaxillary aperture. The thickness of the vascularized mucous membranes in the nasal cavity was obtained up to 6 mm; the surface was smooth and well defined. The paranasal lining was invisible in computed tomography (CT) images because of its thin layer. CT proved to be a very useful method for documentation of the paranasal openings and for evaluation of the state of the mucous membranes in the nasal and paranasal cavities.     

Actinomyces as a Cause of Osteomyelitis of the Nasofrontal Suture in a Gelding

A 7-year-old American Quarter Horse gelding was referred to the JT Vaughan Large Animal Teaching Hospital at Auburn University, College of Veterinary Medicine, for an investigation of a recurrent swelling of the nasofrontal region. Computed tomography examination of the skull was most consistent with a sequestrum of the left nasofrontal suture with associated focal osteomyelitis and left conchofrontal sinusitis. Surgery to remove the sequestrum, debride the devitalized bone, and flush the left conchofrontal sinus was performed. A microbial culture was obtained at the time of surgery, which yielded a mixed heavy growth of an Actinomyces species. Quantitative PCR indicated a species with 93% resemblance to Actinomyces funkei. A treatment course of two weeks of oral chloramphenicol was prescribed. At three-month follow-up, the owner reported resolution of the swelling.     

低扬程泵装置流道损失试验研究与数值模拟

针对大型泵站常用几种进出水流道特点，对其损失进行了详细试验研究，并进行了部分数值模拟，结果显示数值模拟结果与试验结果较为一致。同时结果还表明，不同流道的水力损失特性有较大差异，最大出水流道损失可达最小进水流道损失的4～7倍。由此可进一步对流道结构进行优化，并可根据具体泵装置特点进行进、出水流道的不同组合，确保装置性能最优。     

长江口河口锋区浮游动物生态研究Ⅲ优势种的垂直分布

１９８８年８月丰水期及１２月枯水期间，对长江口羽状锋区水域内浮游动物进行了垂直分布调查研究。经对七个断面２２个测站垂直采集标本进行分析，结果表明，丰水期优势种乌喙尖头Ｆｅｎｉｌｉａａｒｉｒｏｓｔｒｉｓ主要分布于１０─０米层，在Ａ断面密度可达１７００个／米￣３。中华哲水蚤Ｃａｌａｎｕｓｓｉｎｉｃｕｓ主要分布于３０米以浅水层，于Ａ、Ｂ两断面垂直分布现象明显。肥胖箭虫Ｓａｇｉｔｔａｅｎｆｌａｔａ广泛分布于台湾暖流及其所控制或影响的水域，在长江口外Ｂ断面，该种主要分布于２０米以上水层中，其密集分布中心及层次与乌喙尖头及中华哲水蚤高密度聚集有关。枯水期经对四个断面１５个测站的调查分析结果看，冬季型浮游动物垂直分布与夏季丰水期相比有很大差异，大部分浮游动物分层现象不明显。真刺唇角水蚤Ｌａｂｉｄｏｃｅｒ─ａｅｕｃｈａｅｔａ分布于Ａ、Ｂ断面２０米以下水层中；中华哲水蚤则分布于１０米以上水层中。     

连续传代时感染斜纹夜蛾核多角体病毒不同分离株的毒力变化

自然界中的核多角体病毒(NPV)和颗粒体病毒(GV)普遍存在多种分离株,同种病毒不同分离株往往在致病性和作用速度上存在差异[1～3].     

大型立式轴流泵装置流道内部流动特性分析

基于三维不可压缩流体的雷诺平均N-S方程和RNGk-ε湍流模型,采用CFX软件计算了额定转速下180～340 L/s流量范围内6个工况点的立式轴流泵装置内部流动,分析了进水流道和出水流道的流动特性,重点研究进口流动细部结构,同时预测了泵装置的水力性能.计算结果表明:叶轮旋转对进水流道出口轴向流速分布和切向流速分布的影响较小.导叶出口环量对出水流道的流场影响较大,导致隔墩两侧流量分配不均,大流量时隔墩两侧水流流态比较平顺,而小流量时隔墩右侧流道内出现螺旋状水流,两侧水流严重不均衡.通过计算预测了泵装嚣水力性能,并与泵装置模型性能试验结果进行了对比,表明最优工况时数值模拟与试验结果吻合较理想,可以满足工程实际的需要.     

Fixation of chronic suture exostosis in a mature horse

This case report describes the clinical findings, diagnosis and treatment of a 14‐year‐old Warmblood gelding with suture exostosis. The horse was referred to our clinic because of bilateral swelling in the region of the frontal and nasal bone junction and bilateral epiphora. Epiphora was the main concern for the owner and the reason for further investigation and treatment. Radiographic examination showed extensive bone proliferation on the dorsal frontal and nasal bones. Computed tomographic (CT) images further characterised the periosteal proliferation as new bone formation and localised it along the frontonasal and frontolacrimal suture lines. Computed tomographic images also showed pathological changes of both lacrimal ducts. A chronic fracture was suspected to be the cause of the periosteal proliferation, and surgical treatment using 2 small 2.4 Unilock plates was chosen to stabilise the suture between the frontal and nasal bones. The swelling decreased and the epiphora resolved by 6 months post operatively. A CT examination 2 years later showed complete healing.     

轴流泵叶轮导水锥型式设计及其流道水力特性模拟

为探究轴流泵叶轮导水锥的设计方法,揭示导水锥流场的内部流动特性。基于三维不可压缩流体的雷诺平均N-S方程和k-ε湍流模型,结合典型的收缩曲线,设计了维多辛斯基式、五次方曲线式、双三次方曲线式等5种导水锥。利用Fluent软件对各型导水锥进行三维流场计算,分析了导水锥流道的流动特性,归纳了导水锥流场的3个流动部分以及流场轴面的速度分布规律。总结了轴向速度分布均匀度、加权平均偏流角随导水锥收缩型面的变化规律。分析各型导水锥水力损失发现:不同型式导水锥水力损失不同,直锥式导水锥损失略小,其他型式的导水锥水力损失相近。对流场均匀性相比较得出:在导水锥流场急剧收缩的断面上,轴向速度分布均匀度降低,速度加权平均偏流角和径向速度梯度增大。导水锥出口段收缩越平缓,整流能力越出色。综合考虑轴向速度均匀度和速度偏流角等指标,维多辛斯基式导水锥的整流能力最优,出口流场均匀性较好。当导水锥长度为叶轮外径的0.25~0.8倍时,导水锥长度增加,水力损失减小,导水锥出口流场品质提升。结合工程实际应用,给出导水锥长度最优取值范围为叶轮外径的0.5~0.6倍。