共查询到20条相似文献，搜索用时 31 毫秒
1.
This study was aimed to elucidate whether there is significant relationship between the lower calyceal anatomy and stone evacuation
following extracorporeal shock wave lithotripsy(ESWL). From April 1995 to November 1999, 145 patients with lower caliceal
stones underwent ESWL with Storz Modulith SL20 lithotriptor. The pelvicalyecal angle, lower pole infundibular length and width,
and lower pole calyceal pattern of the stone-bearing calyx were measured on pre-ESWL intravenous urograms. Abdominal plain
film and ultrasonography taken of all patients at the 3-month followup showed that the overall stone-free rate was 65% after
3 months. The stone-free rate was significantly correlated to the radiographic anatomical factor, 94% in patients with a pelvicalyceal
angle of 90 degrees or greater, 57% in those with less than 90 degrees pelvicalyceal angle; 80% in those with infundibular
length of 30 mm or less, 59% in those with infundibular length greater than 30 mm; 73% in those with infundibular width greater
than 4 mm, 48% in those with infundibular width of 4 mm or less; 85% in those with a simple calyceal pattern and 41% in those
with a complex one. These findings suggest that the 4 radiographic anatomical factors of the lower pole calyx (pelvicalyceal
angle, infundibular length and width and calyceal pattern) play an important role in stone evacuation after ESWL. Pelvicalyceal
angle of 90 degrees or greater, infundibular length of 30 mm or less and width greater than 4 mm, and simple calyceal pattern
are respectively noted to relate to an improved stone-free status. In contrast, an acute pelvicalyceal angle, long infundibular
length and narrow infundibular width and complex calyceal pattern are individually unfavorable factors for stone emptying
following ESWL. 相似文献
2.
基于TracePro的LED透反式准直器设计与仿真 总被引：1，自引：0，他引：1
利用几何光学原理设计了自由曲面的反光杯和菲涅耳透镜模型,小角度光线通过菲涅耳透射准直,大角度光线通过反光杯准直。使用Matlab软件计算出初始结构参数,利用三维建模工具软件进行曲面拟合并建立几何模型。将几何模型导入TracePro软件进行优化模拟照明。光源采用发光面积1 mm×1 mm的LED芯片,视角为160°。结论:透反式准直器极大提高了光能利用率,不考虑材料吸收等损耗,准直器传输效率约为90%;准直性能与预期相符,半光强角度小于3°。该设计结构紧凑,准直效果良好。 相似文献
3.
4.
郑哲民 《商丘师范学院学报》2012,(6):1-18
系统地记录中国蚱总科中羊角蚱属、柯蚱属及台蚱属的种类,以检索表形式进行分类研究,共记述羊角蚱属33种,柯蚱属29种,台蚱属55种,其中包括7新种,即广东羊角蚱Criotettix guangdongensis sp.nov.、广州柯蚱Coptotettix guangzhouensis sp.nov.、尖峰柯蚱Coptotettix jianfengensis sp.nov.、直缘柯蚱Coptotettix orthomarginis sp.nov.、海南台蚱Formosatettix hainanensis sp.nov.、波股台蚱Formosatettix undulatifemura sp.nov.及黑胫台蚱Formosatettix nigritibia sp.nov..模式标本保存于陕西师范大学动物研究所. 相似文献
5.
目的：探讨经皮肾镜技术治疗肾盏憩室结石的临床疗效。方法：回顾性分析18例诊断为肾盏憩室并结石患者临床治疗资料。其采用B超结合C臂引导下定位穿刺建立经皮肾通道碎石成功,根据个体情况运用扩张憩室盏颈或电灼憩室囊壁两种方法处理肾盏憩室。结果：本组患者均获穿刺碎石成功,手术时间45～120（65．8±7．89）min,无严重并发症;术后随访3。24个月,憩室消失9例,明显缩小8例,1例虽结石复发但可保守观察。结论：经皮肾技术治疗肾盏憩室结石是微创、有效、安全的治疗手段。穿刺路径选择、小心建立通道以及憩室盏颈的处理是治疗肾盏憩室结石成功的关键。 相似文献
6.
Vaginal introital diameter in the evaluation of sexual abuse 总被引：3，自引：0，他引：3
Physical objective markers to aid in the diagnosis of sexual abuse are few. We therefore studied 242 females, ages 1 through 12 years, to determine if the vaginal introital diameter is useful in evaluating a child for sexual abuse. The children were divided into three groups: Group I, history of sexual contact and/or Neisseria gonorrhoeae; Group II, no history of sexual contact but at risk; and Group III, nonabused. A vaginal introital transverse diameter of greater than 4 mm was more prevalent among children in Group I (94%) than in Group II, (5%); or in Group III (0%) (chi 2, p less than .001). Eighty-eight percent of children who complained of penile-vaginal penetration had a vaginal introital diameter greater than 4 mm as compared to 18% of children with no penetration (chi 2, p less than .001). Forty-six percent of children who complained of fondling with penetration had a vaginal introital diameter of greater than 4 mm as compared to 14% in those without a history of penetration (chi 2, p less than .008). Fifty-eight percent of children with more than one encounter had a vaginal introital diameter greater than 4 mm as compared to 29% in those with one encounter (chi 2, p less than .006). In a logarithmic regression analysis, the greatest proportion of children with a vaginal introital diameter greater than 4 mm was observed in the penile-vaginal contact group (chi 2, p less than .00003). The test is not very sensitive but highly specific. The sensitivity drops precipitously at greater than 5 mm without losing the specificity. A vaginal introital diameter of greater than 4 mm is highly associated with sexual contact in children less than 13 years of age. 相似文献
7.
8.
黄端华陈金凤 《福建工程学院学报》2021,(3):294-297
基于微小型万向水准泡,设计专门用于吸量管的垂直辅助工具。采用长宽高为40 mm×30 mm×10 mm的亚克力板或硅胶材料作为支撑,设计直径为9.6mm小孔及深度×直径为6mm×16mm的凹槽。配制平行样品考察方法的重现性,通过运用吸量管垂直辅助工具配制系列平行样品,并进行磺基水杨酸和Fe3+的吸光度测定,获得平行测定结果的相对标准偏差RSD小于1.0%;对标准样品进行对照实验,获得两组对照结果的相对误差分别为0.40%和0.27%。该设计方法表明,吸量管垂直辅助工具能够在实际中帮助使用者调整吸量管的垂直度,获得更准确的分析结果。 相似文献
9.
探讨给定行程速比系数K,摇杆摆角ψ,以及摇杆长度l3(机架长度l4),曲柄长度l1(连杆长度l2)等,运用辅助圆图解设计曲柄摇杆机构的方法。 相似文献
10.
分别定义了松散指数和分层指数描述物料松散和分层的优劣情况,并与筛机参数进行建模分析,得到振动参数对物料的松散和分层具有较大的影响权重,分析了振动参数对松散指数和分层指数的影响规律。利用布谷鸟寻优算法对松散指数和分层指数进行双目标优化,寻求能同时满足较优松散效果和分层效果的参数组合。寻优所得的筛机参数组合为:振动频率20 Hz,振动幅度2.5 mm,振动方向角18°,筛网倾角18°,筛网长度160 mm,筛孔尺寸1.0 mm,筛丝直径0.8 mm。 相似文献
11.
通过对中华长尾螺一个周期的解剖观察，可以发现：中华长尾螺的种群结构、感染台湾棘带吸虫的感染率变化具有一定的季节性规律；同时，不同体长组的中华长尾螺其感染率之间存在着一定的差异，体长小于12．0mm的螺，自然条件下几乎不能感染，大于12．0mm的螺，其感染率随体长的增大而升高． 相似文献
12.
Objective: To evaluate the prevalence of primary iris and/or ciliary body cysts in eyes with shallow anterior chamber and their effect on the narrowing of the anterior chamber angle. Methods: Among the general physical check-up population, subjects with shallow anterior chambers, as judged by van Herick technique, were recruited for further investigation. Ultrasound biomicroscope (UBM) was used to detect and measure the cysts located in the iris and/or ciliary body, the anterior chamber depth (ACD), the angle opening distance at 500 μm (AOD500), and the trabecular-iris angle (TIA). A-scan ultrasonography was used to measure the ocular biometry, including lens thickness, axial length, lens/axial length factor (LAF), and relative lens position (RLP). The effect of the cyst on narrowing the corresponding anterior chamber angle and the entire angle was evaluated by the UBM images, ocular biometry, and gonioscopic grading. The eye with unilateral cyst was compared with the eye without the cyst for further analysis. Results: Among the 727 subjects with shallow anterior chamber, primary iris and ciliary body cysts were detected in 250 (34.4%) patients; among them 96 (38.4%) patients showed unilateral single cyst, 21 (8.4%) patients had unilateral double cysts, and 42 (16.8%) patients manifested unilateral multiple and multi-quadrants cysts. Plateau iris configuration was found in 140 of 361 (38.8%) eyes with cysts. The mean size of total cysts was (0.6547±0.2319) mm. In evaluation of the effect of the cyst size and location on narrowing the corresponding angle to their position, the proportion of the cysts causing corresponding angle narrowing or closure among the cysts larger than 0.8 mm (113/121, 93.4%) was found to be significantly higher than that of the cysts smaller than 0.8 mm (373/801, 46.6%), and a significant higher proportion was also found in the cysts located at iridociliary sulcus (354/437, 81.0%) than in that at the pars plicata (131/484, 27.1%). In evaluating the effect of the cyst on the entire anterior chamber angle, the eyes with multiple and multi-quadrants cysts manifested significant narrowing of the entire anterior chamber angle as compared with the eyes without cysts, based on the data analysis in comparison of TIA, AOD500, and gonioscopic grading evaluation. The unilateral single or double cysts in the eyes had no significant effect on narrowing of anterior chamber angle as compared with eyes without cysts. The iris and/or ciliary body cysts did not seem to affect the axial length, ACD, lens thickness, RLP, LAF. Conclusions: The prevalence of primary iris and ciliary body cyst was 34.4% in the subjects with shallow anterior chamber. The cysts larger than 0.8 mm, locating at iridociliary sulcus, or multiple and extensive cysts were inclined to cause the angle narrowing or closure. 相似文献
13.
吕庆洲 《淮南职业技术学院学报》2006,6(1):59-63
为了更加精确、快速地设计曲柄摇杆机构,利用借助辅助圆设计曲柄摇杆机构的原理,通过对曲柄摇杆机构各杆件长度以及运动时所处的几个特殊的几何位置关系进行了数学计算和分析,得到了具有急回特性的曲柄摇杆机构获得最佳传动角的条件和一组设计计算公式;根据所给的具体条件,选择不同的计算公式,采用直接计算法或计算机辅助设计法,确定具有最佳传动角和急回特性的曲柄摇杆机构的机构布置以及各杆件的结构尺寸。 相似文献
14.
In this paper, the effect of the grinding undercut of the raceways on the longitudinal pressure distribution of the profiled rollers, which are the most popular axial profile employed by the bearing manufacturers, was discussed. Based on the profiled roller geometrical equations and numerical calculation of three-dimensional elastic contact problems of finite length, a new numerical method for calculating the crown drop evaluation considering the effect of grinding undercut was used. The analyses of two structure case, that roller length is greater or less than raceway width, were carried out and compared with each other. The Results show that the width of grinding undercut must be considered in determining the crown drop of rollers. 相似文献
15.
１ Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｒｏｌｌｅｒｂｅａｒｉｎｇｓａｒｅｕｓｅｄｔｏｓｕｐｐｏｒｔｈｅａｖｙｌｏａｄｓ．Ｉｆｔｈｅｇｅｎｅｒａｔｒｉｃｅｓｏｆｒｏｌｌｅｒａｎｄｒａｃｅｗａｙｓａｒｅａｂｓｏｌｕｔｅｌｙｓｔｒａｉｇｈｔａｎｄｉｆｔｈｅｒｏｌｌｅｒｌｅｎｇｔｈｄｏｅｓｎｏｔｃｏｉｎｃｉｄｅｗｉｔｈｔｈｅｒａｃｅｗａｙｗｉｄｔｈ,ｔｈｅｎｎｏｔｗｉｔｈｓｔａｎｄｉｎｇｒｅｌａｔｉｖｅｌｙｌｉｇｈｔｌｏａｄｉｎｇ,ｅｄｇｅｓｔｒｅｓｓｅｓｗｉｌｌａｒｉｓｅａｔｔｈｅｅｎｄｓｏｆｔｈｅｃｏｎｔａ… 相似文献
16.
Type-dependent differential expression of neuropeptide Y in chicken hypothalamus （Gallus domesticus）
Chen GQ Hu XF Sugahara K Chen JS Song XM Zheng HC Jiang YQ Huang X Jiang JF Zhou WD 《Journal of Zhejiang University. Science. B》2007,8(11):839-844
Neuropeptide Y (NPY) is one of the most important orexigenic agents in central regulation of feeding behavior, body weight and energy homeostasis in domestic chickens. To examine differences in the hypothalamic NPY between layer-type and meat-type of chickens, which are two divergent kinds of the domestic chickens in feeding behavior and body weight, we detected mRNA levels of NPY in hypothalamic infundibular nucleus (IN), paraventricular nucleus (PVN) and lateral hypothalamic area (LHA) of these two types of chickens using one-step real time RT-PCR. The meat-type chicken had more food daily (about 1.7 folds) and greater body weights (about 1.5 folds) and brain weights than the layer-type chicken at the age of 14 d. In the meat-type of chicken, NPY mRNA levels of the IN and PVN were significantly greater than those of the LHA, and were not significantly different between the IN and PVN. However, in the layer-type of chicken, NPY mRNA levels were significantly greater in the IN than those in the LHA and PVN, and were not significantly different between the PVN and LHA. In all these hypothalamic regions, the layer-type of chicken had significantly higher NPY mRNA levels than the meat-type chicken did. These results suggest the expression of NPY in the hypothalamus has a type-dependent pattern in domestic chickens. 相似文献
17.
Objective: To observe the accuracy of femoral preparation and the position of the cementless prosthesis in femoral cavity, and to compare the results between the computer-assisted surgical group (CASPAR) and the conventional group. Methods: Ten femoral components were implanted either manually or by CASPAR in cadaver femurs. The specimens were cut to 3 mm thick slices. Microradiograms of every slice were sent to a computer for analysis with special software (IDL). The gaps and the medullary cavities between component and bone, the direct bone contact area of the implant surface, the gap width and the percentage of gap and bone contact area were measured in every slice. Results: In the proximal implant coated with HA of the CASPAR group, the average percentage of bone contact reached 93.2% (ranging from 87.6% to 99.7%); the average gap percentage was 2.9% (ranging from 0.3% to 7.8%); the maximum gap width was 0.81 mm and the average gap width was only 0.20 mm. While in the conventional group, the average 相似文献
18.
吴立东 《浙江大学学报(A卷英文版)》2004,5(10):1270-1278
Objective: To observe the accuracy of femoral preparation and the position of the cementless prosthesis in femoral cavity, and to compare the results between the computer-assisted surgical group (CASPAR) and the conventional group. Methods: Ten femoral components were implanted either manually or by CASPAR in cadaver femurs. The specimens were cut to 3 mm thick slices. Microradiograms of every slice were sent to a computer for analysis with special software (IDL). The gaps and the medullary cavities between component and bone, the direct bone contact area of the implant surface,the gap width and the percentage of gap and bone contact area were measured in every slice. Results: In the proximal implant coated with HA of the CASPAR group, the average percentage of bone contact reached 93.2% (ranging from 87.6% to 99.7%); the average gap percentage was 2.9% (ranging from 0.3% to 7.8%); the maximum gap width was 0.81 mm and the average gap width was only 0.20 mm. While in the conventional group, the average percentage of bone contact reached 60.1% (ranging from 49.2% to 70.4%); the average gap percentage was 32.8% (ranging from 25.1% to 39.9%); the maximum gap width was 2.97 mm and the average gap width was 0.77 mm. The average gap around the implant in the CASPAR group was only 9% of that in the manual group; the maximum and average gap widths were only about 26% of those in the manual group. On the other hand, the CASPAR group showed 33% higher bone contact than the manual group. Conclusion: With the use of robotics-assisted system, significant progress can be achieved for femoral preparation in total hip arthroplasty. 相似文献
19.
针对激光选区熔化成形倾斜薄壁件尺寸精度低、成形质量差等问题,应用响应曲面法研究工艺参数及倾斜角度对薄壁件壁厚的影响,建立倾斜角度、工艺参数与壁厚相对误差关系模型。结果表明:倾斜角度对壁厚的影响最大,激光功率次之。由于倾斜角度改变,薄壁件悬垂面粉末支撑区域不同,导热效果存在差异,激光功率与扫描间距对于不同倾斜角度的薄壁件壁厚影响不同。其中,激光功率对45°倾斜薄壁件壁厚的影响最大,当激光功率选择150~350W时,壁厚相对误差最大差值为24%而扫描间距对90°倾斜薄壁件壁厚的影响最大,当扫描间距选择0.1~0.2mm时,壁厚相对误差最大差值为9.5%,合理的工艺参数能够有效降低壁厚相对误差。 相似文献
20.
用单摆法测量重力加速度是普通物理实验中常用的方法,但在实验中,摆角、摆长和周期数常常对重力加速度的测量误差产生一定的影响.文章主要分析不同摆角、摆长及周期数三个条件对测重力加速度的影响,最终由处理分析结果可知,在普通物理实验室里,取摆角、摆长=47或55cm、周期数次,处理得到的重力加速度与本地的理论计算值很接近. 相似文献