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91.
循证医学决策模式的建立与应用 总被引:1,自引:1,他引:0
循证医学决策模式是建立在对客观的医学研究证据,长期的临床工作经验,及不同患的医疗需求进行综合分析基础上的最佳医疗方案。其建立和应用对提高医疗质量,改善医疗服务质量具有重要意义。树立循证医学决策意识,建立循证医学决策系统,实施循证医学决策管理将为军队医疗系统实现全面品质管理提供可靠依据。 相似文献
92.
通过对动物模型实验治疗的病理观察,评价全肺大容量灌洗治疗矽肺的效果,并优选灌洗液。对40只家兔和10只幼猪经SiO2染尘处理后,各随机分为药物组、盐水组和对照组。4~5周后施行全肺大容量灌洗。治疗后3~5个月处死各组动物,进行病理双盲检查。经统计学秩和检验,兔与猪各组肺矽结节纤维化级别分布的差异有非常显著意义(P<0.005)。经卡方检验,各灌洗组的纤维化程度与对照组相比,差异亦有非常显著意义(P<0.01)。灌洗液中药与盐水比,P<0.05;盐水与西药比,P<0.05。兔和猪矽肺各灌洗组的效果明显优于对照组。灌洗液中药优于盐水,盐水又优于西药 相似文献
93.
Simon Vinitski Carlos Gonzalez Feroze Mohamed Tad Iwanaga Robert L. Knobler Kamil Khalili John Mack 《Magnetic resonance in medicine》1997,37(3):457-469
Our aim was to develop an accurate multispectral tissue segmentation method based on 3D feature maps. We utilized proton density (PD), T2-weighted fast spin-echo (FSE), and T1-weighted spin-echo images as inputs for segmentation. Phantom constructs, cadaver brains, an animal brain tumor model and both normal human brains and those from patients with either multiple sclerosis (MS) or primary brain tumors were analyzed with this technique. Initially, misregistration, RF inhomogeneity and image noise problems were addressed. Next, a qualified observer identified samples representing the tissues of interest. Finally, k-nearest neighbor algorithm (k-NN) was utilized to create a stack of color-coded segmented images. The inclusion of T1 based images, as a third input, produced significant improvement in the delineation of tissues. In MS, our 3D technique was found to be far superior to that based on any combination of 2D feature maps (P < 0.001). We identified at least two distinctly different classes of lesions within the same MS plaque, representing different stages of the disease process. Further, we obtained the regional distribution of MS lesion burden and followed its changes over time. Neuropsychological aberrations were the clinical counterpart of the structural changes detected in segmentation. We could also delineate the margins of benign brain tumors. In malignant tumors, up to four abnormal tissues were identified: 1) a solid tumor core, 2) a cystic component, 3) edema in the white matter, and 4) areas of necrosis and hemorrhage. Subsequent neurosurgical exploration confirmed the distribution of tissues as predicted by this analysis. 相似文献
94.
笔者提出了对Reed-Frost模型的学术评论,并新建了一种Reed-Frost模型的改进模型。该改进模型全面考虑了隐性感染者的产生、传染作用及向免疫者的转化。应用这个模型,模拟了NewEngland的麻疹流行和中国上海市某保育院的水痘流行,结果颇为理想。该模型包括了基本的流行要因,故能用以解释流行过程,并可帮助流行病学工作者理解隐性感染在传染病流行过程中的作用。 相似文献
95.
rhGM-CSF对小鼠口腔粘膜损伤的防治作用 总被引:1,自引:0,他引:1
目的:探讨rhGM-CSF促进口腔腔溃愈合的作用机制。方法:取体外培养的胎儿口腔粘膜成纤维细胞,用rhGM-CSF刺激成纤维细胞后第2、4、6天用细胞计数及^3H-胸腺嘧啶掺入法(^3H-TdR)测定其增殖情况,结果rhGM-CSF对胎儿口腔粘膜成纤维细胞增殖及DNA合成有刺激作用,在80-100ng/ml时,细胞生长达到最佳状态,过高浓度rhGM-CSF的刺激作用反而下降。结论:rhGM-CSF可以通过刺激成纤维细胞增殖及DNA合成促进口腔溃疡愈合。 相似文献
96.
Acetylcholinesterase Adaptation to Voluntary Wheel Running is Proportional to the Volume of Activity in Fast, but not Slow, Rat Hindlimb Muscles 总被引:4,自引:0,他引:4
Victor Gisiger Manon Bélisle Phillip F. Gardiner 《The European journal of neuroscience》1994,6(5):673-680
Chronic enhancement of neuromuscular activity by forced exercise training programmes results in selective adaptation of the G4 acetylcholinesterase (AChE) molecular form in hindlimb fast muscles of the rat, with only minor and non-selective AChE changes in the soleus. In order to shed further light on the physiological significance of this G4 adaptation to training, we turned to a voluntary exercise model. The impact of 5 days and 4 weeks of voluntary wheel cage running on AChE molecular forms was examined in four hindlimb fast muscles and the slow-twitch soleus from two rat strains. Inbred Fisher and Sprague– Dawley rats, placed in live-in wheel cages, exercised spontaneously for distances which progressively increased up to an average of ∼3 and 18 km/day, respectively, by the end of week 4. Fast muscles responded to this voluntary activity by massive G4 increases (up to 420%) with almost no changes in A12 , so that by week 4 the tetramer became the main AChE component of these muscles. The additional G4 was composed primarily of amphiphilic molecules, suggesting a membrane-bound state. The G4 content of fast muscles was highly correlated with the distance covered by the rats during the 5 days before they were killed ( r = 0.850-0.879, P < 0.001 in three muscles). The soleus muscle, in turn, responded to wheel cage activity by a marked selective reduction of its asymmetric forms—up to 45% for A12 . This A12 decline, already maximal by day 5 of wheel cage running, showed no relationship with the distance covered. The present results constitute strong new evidence suggesting that the role of AChE in neuromuscular transmission is not limited solely to the rapid inactivation of just-released acetylcholine. 相似文献
97.
An experimental model for canine visceral leishmaniasis 总被引:6,自引:1,他引:5
PEDRO ABRANCHES GABRIELA SANTOS-GOMES NURIT RACHAMIM† LENEA CAMPINO LIONEL F. SCHNUR‡ CHARLES L. JAFFE† 《Parasite immunology》1991,13(5):537-550
Seven mixed-breed dogs were challenged with either promastigotes or amastigotes of Leishmania donovani infantum strains recently isolated from naturally infected dogs. Different routes and numbers of parasites were utilized and each dog was monitored for at least 1 year post-infection. Anti-parasite specific antibody levels were measured by enzyme-linked immunosorbence, immunofluorescence, crossed-immune electrophoresis and Western blotting on crude antigen. Western blotting on two pure parasite proteins, dp72 and gp70-2, was also done. Mitogenic and antigen-specific stimulation of peripheral blood lymphocytes was monitored; and the haematological, clinical and parasitological parameters measured. Dogs challenged with amastigotes exhibited a more pronounced humoral response to leishmanial antigens. Only in one case was strong antigen-specific proliferation detected. Clinical signs of disease, including hypergammaglobulinaemia, enlarged lymph nodes and the presence of parasites, were also more apparent in the dogs challenged with amastigotes. None of the seven dogs died. Serum antibodies to leishmanial antigens were apparent between 1.5 to 3 months following challenge and correlated with the appearance of enlarged lymph nodes, hypergammaglobulinaemia and the presence of parasites in tissue biopsies. Serum antibodies remained chronically high in these dogs throughout the period of the study. Only one dog (1/3) challenged intravenously with promastigotes and the dog challenged intradermally with amastigotes produced transient antibody responses to leishmanial antigen. 相似文献
98.
本文运用模糊数学原理,对东台市1993年7月份市面上的全脂乳粉抽查监测结果进行卫生质量综合评价,结果令人满意,从而为乳粉卫生质量评比建立了客观有效的评价模型。 相似文献
99.
由头皮上电极所记录下的EEG信号是大脑中各种电活动,尤其是神经元电活动,互相耦合而产生的电位变化的整体反映。有一种看法认为,表面看来随机、无规则的EEG信号,实际上它的变化只是由少量几个动力学参量控制着的非线性过程。根据这个假定,我们提出使用多复指数(MCE)模型来描述EEG信号的想法。文中首先简要地介绍了用来估计时序信号MCE模型参数的非调和Fourier展开算法(NHFE)的基本思想。然后,对一个叠加有白噪声、具有4个频率成分的模拟信号,用NHFE算法估计出其MCE模型参数,并把所得的结果与用经典的周期图谱分析方法、AR模型谱分析方法所得到的信号频谱作了比较。结果表明,在SNR高的条件下,NHFE算法所估计出的模型参数能更客观地反映信号的固有特性。基于目前的有关EEG形成的假设,应用MCE模型来描述EEG将更能反映出其特征。因此,我们对MCE模型及其参数在EEG数据分析中的几种可能应用作了初步尝试。这些应用包括:EEG信号段(或一段诱发电位,或一段事件关联电位)的特征参数的提取,这些特征参数包括优势频率值、独立的频率成分个数、幅度值、正负衰减指数的个数、频带宽度与幅度乘积(能量);EEG的频率调制特性的粗略描述等。从而看到了用通常信号分析方法所看不到的EEG信号中所反映的大脑活动的变化。由于用MCE模型及其参数来描述EEG的方法更符合目前关于大脑非线性动力学行为的假设,所以这一方法将是表示EEG信号的有效途径之一。另外,MCE模型方法在EEG信号的模拟研究与数据压缩等方面也将是有用的。文中还讨论了NHFE算法应用中的一些问题。 相似文献
100.
Camilla Nyboe Jonas A. Funder Morten H. Smerup Hans Nygaard J. Michael Hasenkam 《European journal of cardio-thoracic surgery》2006,29(6):1008-1013
Objective: Mechanical heart valves can cause thromboembolic complications, possibly due to abnormal flow patterns that produce turbulence downstream of the valve. The objective of this study was to investigate whether three different bileaflet valve designs would exhibit clinically relevant differences in downstream turbulent stresses. Methods: Three bileaflet mechanical heart valves (Medtronic Advantage®, CarboMedics© Orbis™ Universal and St. Jude Medical® Standard) were implanted into 19 female 90 kg pigs. Blood velocity was measured during open chest conditions in the cross sectional area downstream of the valves with 10 MHz ultrasonic probes connected to a modified Alfred® Pulsed Doppler equipment. As a measure of turbulence, Reynolds normal stress (RNS) was calculated at three different cardiac output ranges (3–4, 4.5–5.5, 6–7 L/min). Results: Data from 12 animals were obtained. RNS correlated with increasing cardiac outputs. The highest instantaneous RNS observed in these experiments was 47 N/m2, and the mean RNS taken spatially over the cross sectional area of the aorta during systole was between 3 N/m2 and 15 N/m2. In none of the cardiac output ranges RNS values exceeded the lower critical limit for erythrocyte or thrombocyte damage for any of the valve designs. Conclusions: Reynolds normal stress values were below 100 N/m2 for all three valve designs and the difference in design was not reflected in generation of turbulence. Hence, it is unlikely that any of the valve designs causes flow induced damage to platelets or erythrocytes. 相似文献