DETECTION OF PNEUMOTHORAX AND PLEURAL EFFUSION WITH HORIZONTAL BEAM RADIOGRAPHY

Forty‐seven patients with a known history of thoracic trauma or clinical suspicion of pneumothorax were selected for thoracic imaging. The patient population was composed of 42 dogs and five cats. Standard vertical beam (VB) left and right lateral and ventrodorsal/dorsoventral (VD/DV) projections were obtained for each patient, and at least one horizontal beam (HB) projection (VD projection made in lateral recumbency). A total of 240 images were reviewed. Subjective assessment for the presence and degree of pneumothorax and pleural effusion was made more confidently with HB projections. Pneumothorax was identified in at least one projection in 26 patients (26 dogs) and pleural effusion in 21 patients (19 dogs and two cats). Pneumothorax and pleural effusion were present concurrently in 17 dogs. Pneumothorax and pleural effusion were graded for each image as absent, mild, moderate, or severe. Right (P<0.001) and left (P<0.05) lateral HB VD projections and the standard VB left lateral projection (P<0.05) were significantly more likely to detect and grade pneumothorax severely than the VB VD/DV views. The right lateral HB projection had the highest rate of detection and gradation of severity for pneumothorax compared with other views. VD/DV projections had the lowest sensitivity for detection of the pneumothorax and gradation of severity for pneumothorax and pleural effusion. No significant difference in diagnosis (P=0.9149) and grade (P=0.7757) of pleural effusion were seen between views, although the left lateral HB had both the highest rate of detection and grade of severity.     

顶进框构桥线路加固的计算

在城市立交桥建设中,下穿桥施工经常采用顶进施工方法,为了保证铁路或轻轨线路正常运营,线路加固措施显得尤为重要。本文以前进大街下穿卫星路顶进框构桥工程为例,详细介绍了横抬梁法加固线路的计算,希望能为同类施工提供借鉴。     

4×32.18m预应力混凝土小箱梁计算浅析

桥梁上部计算在整个桥梁设计中占有相当重要的作用。本次设计主要是对4×32.18m预应力混凝土小箱梁进行各种荷载组合作用下的截面强度及刚度验算。本次设计计算主要运用的软件有:桥梁博士、QJS、Microsoft Excel、AutoCAD等软件。     

扣件式钢管模板高支撑架事故分析和使用安全

目前,扣件式钢管模板高支撑架在建筑施工过程中得到广泛应用,但由于在安全方面存在事故的多发性,导致坍塌事故频繁发生.本文从设计、材料、施工和管理等方面,分析了造成扣件式钢管模板高支撑架倒塌事故的原因,并提出了具体的安全防范对策,对指导实际工程具有一定的参考价值.     

离子束诱变小麦的数量性状研究(英文)

[目的]阐述离子束诱变植物的数量性状。[方法]调查了离子束诱变小麦同一母本后代的特殊变异表型、农艺性状、蛋白质和湿面筋含量。[结果]有的个体表现出形态学多样性。株高、穗长和蛋白质含量受离子束显著影响,有效分蘖数和湿面筋含量受到轻微影响。多重比较表明各组性状存在不稳定性。[结论]离子束辐射呈现多样性和不定向性的特点,可以对同一突变体造成多种变异。后代性状的不稳定性暗示同一辐射区域的细胞也可能有不同命运。特定性状可能要经过数代才会稳定。离子束辐射效应可能是直接辐射损伤、间接辐射损伤和旁观者效应和自适应效应的综合效应。     

重复频率3Hz、100mJ高光束质量钕玻璃放大器的研制

研制了具有放大纳秒方形激光脉冲的高光束质量、高稳定的激光二极管(LD)抽运的钕玻璃激光放大器。为了获得较高的输出能量,采用LD泵浦的"串联式双程放大"高增益组件进行能量放大。为了获得高光束质量的光斑,利用液晶空间光调制器(LCSLM)对光束近场分布进行空间整形,使之产生特定的空间分布,进而对后级放大器增益不均匀性进行光学预补偿。放大器工作波长为1 053nm,工作频率为3 Hz,输入1nJ的3ns方形激光脉冲,输出激光脉冲能量为100mJ、光束口径为10mm×10mm的方光斑,能量不稳定度小于2%(均方根),净增益大于109。光束的近场调制度小于1.3∶1,远场焦斑衍射极限小于2DL,远场角漂移小于9.5μrad。     

Ar+离子束介导白棉全DNA转化彩棉中酚类物质的研究

通过25 KeV不同剂量Ar 离子注入和DNA溶液浸泡法,将白棉全DNA导入彩棉.观察了Ar 离子注入后处理及ck的发芽率;再以彩棉开花期叶片为实验材料,研究茎叶中的茶多酚及多酚氧化酶含量的变化.结果表明:随Ar 离子剂量的升高,发芽率呈现马鞍形变化,GTP、PPO含量也都有不同程度的增长;这说明Ar 离子注入可显著促进外源DNA导入受体,增加了后代的变异频率并且增强彩棉的抗病性.     

混凝土箱梁桥面板计算与试验分析

混凝土箱梁板面板计算,一般采用近似计算,通过混凝土箱梁板面板实测值与几种近似法计算值的对比分析,建议设计中采用美国学者Westergard法计算桥面板的内力。该法也是美国桥梁设计规范计算桥面板的理论基础。     

In vitro prediction of canine urolith mineral composition using computed tomographic mean beam attenuation measurements

Determination of urolith mineral composition is critical for management of urolithiasis in dogs and cats. Using computed tomography, urolith physical density, and hence chemical composition, can be quantified using mean beam attenuation measurements (Hounsfield units; HU). This study was designed to establish in vitro reference ranges for three types of compositionally pure uroliths retrieved from dogs. Sixty-six canine uroliths (22 uric acid, 21 calcium oxalate, 14 struvite, nine mixed or compound) were placed in a phantom array. Uroliths were scanned at 120 kVp, 200 mA, and 80 kVp, 200 mA. The region of interest (ROI) for mean HU calculation was determined using two techniques, and reference ranges were calculated for each kVp using either ROI technique. HU for urolith types of pure composition were statistically different (Wilcoxon's two-sample test, P < 0.0083 [Bonferonni correction with six comparisons for total P < 0.05]) using both ROI techniques at either kVp. Struvite uroliths were not statistically different from mixed or compound uroliths. The accuracy for determination of composition of pure uroliths ranged from 86% to 93%; the prediction accuracy for each urolith mineral type and for all uroliths in general was highest when the ROI was hand-drawn just within the visible urolith border at 80 kVp. Technique of ROI determination and kVp that yielded the highest sensitivity, specificity, and positive and negative predictive values varied for each urolith type. Therefore, in this study, HU could be used to differentiate three types of uroliths of pure mineral composition in vitro. Further studies are needed to determine the predictive value of HU in vivo.     

型钢混凝土结构施工安全研究

针对对型钢混凝土柱与梁的施工,本研究结合实际工程中的问题对其施工质量和施工安全进行了说明,并对安全保证措施、安全措施的执行进行了探讨.重点对于型钢混凝土结构的混凝土浇筑工作以及浇筑质量、施工安全进行了讨论