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排序方式: 共有630条查询结果,搜索用时 15 毫秒
1.
2.
A framework for evaluating image segmentation algorithms. 总被引:4,自引:0,他引:4
Jayaram K Udupa Vicki R Leblanc Ying Zhuge Celina Imielinska Hilary Schmidt Leanne M Currie Bruce E Hirsch James Woodburn 《Computerized medical imaging and graphics》2006,30(2):75-87
The purpose of this paper is to describe a framework for evaluating image segmentation algorithms. Image segmentation consists of object recognition and delineation. For evaluating segmentation methods, three factors-precision (reliability), accuracy (validity), and efficiency (viability)-need to be considered for both recognition and delineation. To assess precision, we need to choose a figure of merit, repeat segmentation considering all sources of variation, and determine variations in figure of merit via statistical analysis. It is impossible usually to establish true segmentation. Hence, to assess accuracy, we need to choose a surrogate of true segmentation and proceed as for precision. In determining accuracy, it may be important to consider different 'landmark' areas of the structure to be segmented depending on the application. To assess efficiency, both the computational and the user time required for algorithm training and for algorithm execution should be measured and analyzed. Precision, accuracy, and efficiency factors have an influence on one another. It is difficult to improve one factor without affecting others. Segmentation methods must be compared based on all three factors, as illustrated in an example wherein two methods are compared in a particular application domain. The weight given to each factor depends on application. 相似文献
3.
A randomized controlled trial of electromagnetic therapy in the primary care management of venous leg ulceration 总被引:1,自引:1,他引:0
OBJECTIVE: The aim was to establish the potential efficacy, tolerabilityand side-effect profile of electromagnetic therapy as an adjunctto conventional dressings in the treatment of venous leg ulcers. METHOD: A prospective, randomized, double blind controlled clinicaltrial was carried out in a dedicated leg ulcer clinic basedin one urban general practice. Nineteen patients with leg ulcersof confirmed venous aetiology were assessed. The main outcomemeasures were rate and scale of venous leg ulcer healing, changesin patient-reported pain levels, quality of life, degree ofmobility, side effect profile and acceptability to patientsand staff. RESULTS: Sixty-eight per cent of patients attending this dedicated clinicachieved improvements in the size of their ulcer (4, 21%, healedfully) and in reduced pain levels (P < 0.05) during the trial,despite the chronicity of ulcer histories. Patients treatedwith electromagnetic therapy at 800 Hz were found at day 50to have significantly greater healing (P < 0.05) and paincontrol (P < 0.05) than placebo therapy or treatment with600 Hz. All patients reported improved mobility at the end ofthe study. The electromagnetic therapy was well tolerated bypatients, with no differences between groups in reporting adverseevents, and proved acceptable to staff. CONCLUSION: Despite the small numbers in this pilot study, electromagnetictherapy provided significant gains in the healing of venousleg ulcers and reduction in pain. Keywords. Electromagnetic therapy, RCT, leg ulcers, primary care. 相似文献
4.
Intestinal schistosomiasis japonica: CT-pathologic correlation 总被引:1,自引:0,他引:1
Lee RC; Chiang JH; Chou YH; Rubesin SE; Wu HP; Jeng WC; Hsu CC; Tiu CM; Chang T 《Radiology》1994,193(2):539
5.
笔者在淮南地区采集50种(500份)中药材,应用清水漂浮法和塔氏电热集螨器集螨法对其进行了分离,其结果,所有样本中均有粉螨孳生,共分离出粉螨34种,隶属7科19属。因此认为,中药材粉螨污染严重,应加强对中药材孳生螨类的防治。 相似文献
6.
医院后勤服务社会化的思考 总被引:3,自引:1,他引:2
诸葛立荣 《中华医院管理杂志》1999,15(9):548-550
医院后勤服务社会化是医院后勤改革的关键,面对改革的趋势,我们必须认真研究、悉心思考、统一认识、采取措施,改变目前医院后勤管理中不适应市场机制和现代医院管理的落后状态,主动寻找对策,充分利用和发掘现有后勤资源,在保证医院中心工作、“一切以病人为中心”为目标的前提下,把医院后勤管理和服务职能分离,认真操作、大胆探索,加快医院后勤服务社会化进程 相似文献
7.
坦克作业条件下驾驶室内挥发性有机物定性分析 总被引:5,自引:2,他引:3
目的:了解某型坦克作业条件下驾驶室内挥发性有机物的污染状况,为制定防治措施提供科学依据。方法:应用气相色谱-质谱联用技术(GC-MS)对某型坦克单纯行进,行进打炮,停车打炮等工作状态下驾驶室内以及废气排放口的挥发性有机物(VOCs)进行了全谱分析,结果:共检出134种污染物质,包括脂肪烃类,单环芳烃类,多环芳烃类以及机酸,碱,酯,醛,酮,杂环化合物等。结论:实验结果表明这些物质主要来源于油类蒸汽, 相似文献
8.
Non-invasive detection of fecal protein kinase C betaII and zeta messenger RNA: putative biomarkers for colon cancer 总被引:2,自引:0,他引:2
Davidson LA; Aymond CM; Jiang YH; Turner ND; Lupton JR; Chapkin RS 《Carcinogenesis》1998,19(2):253-257
We have developed a non-invasive method utilizing feces, containing
sloughed colonocytes, as a sensitive technique for detecting diagnostic
colonic biomarkers. In this study, we used the rat colon carcinogenesis
model to determine if changes in fecal protein kinase C (PKC) expression
have predictive value in monitoring the neoplastic process. Weanling rats
were injected with saline or azoxymethane (AOM) and 36 weeks later fecal
samples and mucosa were collected, poly A+ RNA isolated, and quantitative
RT-PCR performed using primers to PKC betaII and zeta. Fecal PKC betaII and
zeta mRNA levels were altered by the presence of a tumor, with
tumor-bearing animals having a 3-fold higher (P < 0.05) PKC betaII
expression as compared with animals without tumors. In addition,
AOM-injection increased mucosal PKC betaII mRNA expression compared with
saline controls. No effect of tumor incidence on mucosal PKC betaII
expression was observed. In contrast, fecal PKC zeta expression was
2.5-fold lower (P < 0.05) in animals injected with azoxymethane versus
saline. Since tumor incidence exerts a reciprocal effect on fecal PKC
betaII and zeta mRNA expression, data were also expressed as the ratio
between PKC betaII and zeta. The isozyme ratio was strongly related to
tumor incidence, i.e. ratio for animals with tumors was 2.18 +/- 1.25,
animals without tumors was 0.50 +/- 0.16, P = 0.025. We demonstrate that
the expression of fecal PKC betaII and zeta may serve as a noninvasive
marker for development of colon tumors. A sensitive technique for the
detection of colon cancer is of importance since early diagnosis can
substantially reduce mortality.
相似文献
9.
Liu Luying Shen Dongxia Jin Chunlei Zhuge Zhengbing Gong Yingxia Zhu Yuanyuan Chen Zhong 《中国药理通讯》2005,22(4):30-31
The hypothesis that histaminergic system is involved in learning and memory is supported by many studies. However, the functions of brain histamine in learning and memory are still controversial. To explore the exact role of histamine and related mechanisms, we trained wild-type (WT) and knock - out mice lacking the histidine decarboxylase gene ( HDC^-/- ) using Pavlovian fear conditioning. 相似文献
10.
目的 总结对新生儿先天性甲状腺功能低下症的筛查和诊治经验,了解扬州地区先天性甲状腺功能低下症的发病率。方法 对出生72h的新生儿采集足跟末梢血,以时间分辨免疫法测血斑中促甲状腺激素(TSH)。结果 本筛查中心2002年7月-2004年12月扬州地区新生儿筛查结果显示,初筛阳性病例106例,确诊20例,先天性甲低的发病率为0.07%,复检率0.38%,召回率98%。结论 先天性甲状腺功能减低症因其出生时没有或很少有甲低的症状和体征而容易误诊,在新生儿期对其筛查可以减少误诊率,使患儿得到早期诊断和治疗,防止症状的发生和发展,避免发生不可逆智能障碍,随着《母婴保健法》的颁布,新生儿筛查工作正在逐步开展,进行大规模的新生儿筛查是非常有必要的。 相似文献