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31.
OBJECTIVE: To evaluate the effect of maternal age on outcomes for IVF and GIFT in women 40 to 45 years of age. DESIGN: Retrospective. SETTING: Boston IVF, a free-standing university-affiliated IVF and GIFT unit. PATIENTS: A total of 2,931 cycles of IVF and 1,826 cycles of GIFT were analyzed in women undergoing assisted reproductive technologies (IVF or GIFT) using autologous eggs. INTERVENTIONS: Medical records of patient outcomes were reviewed. RESULTS: For patients undergoing IVF, the cancellation rate for initiated cycles showed significant differences in women aged 25 to 39 (38.3%), women aged 40 to 43 (49.5%), and women aged 44 to 45 years (69.5%). A significantly lower delivery rate per stimulation and delivery rate per retrieval was found in women aged 40 to 43 years when compared with women aged 25 to 39 years. No deliveries occurred in 59 cycles in women aged 44 to 45 years, thereby representing a significant difference when compared with both women aged 25 to 39 years and women aged 40 to 43 years. For patients undergoing GIFT, the cancellation rate for initiated cycles was significantly higher in women aged 40 to 43 (25.0%) and 44 to 45 years (31.0%) when compared with women aged 25 to 39 years (15.1%). A significantly lower delivery rate per stimulation and delivery rate per retrieval was found in women aged 40 to 43 and 44 to 45 years when compared with women aged 25 to 39 years. CONCLUSIONS: Success rates for IVF and GIFT decline significantly in women > 40 years old. Women aged > or = 44 years are unlikely to benefit from the use of IVF and GIFT. 相似文献
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The cardiovascular effects of single 100-mg doses of guanethidine were assessed in hypertensive patients by measurement of arterial pressure, heart rate, and systolic time intervals. In the 3-hr period following a dose there was no evidence of an inotropic effect. Therefore, large doses of guanethidine as required for the guanethidine loading regimen would seem to be safe even in patients in whom inotropic effects of released catecholamines would be contraindicated. 相似文献
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The results of this study, using cultured amniotic fluid cells (AFC) and colcemid, together with results of several other investigators who worked with colcemid and DNA synthesis, have led to the proposal of a hypothesis suggesting a mechanism by which tetraploidy may be induced. Data from this study of 24,455 mitotic spreads indicate increased concentrations of colcemid, as well as extended exposure times, results in a higher incidence of tetraploidy in cultured AFC, with no concomitant increase in the unexposed control cells. 相似文献
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VM Cheremisin VE Savello IE Tiurin NA Anosov NL Turanov MV Shapovalov 《Canadian Metallurgical Quarterly》1998,(4):4-9
The paper presents the data available in the literature on computed tomographic angiography and the first experience with it to study thoracic vessels. It details the principles of spiral computed tomography and CT angiography. Practical aspects of their implementation, as well as basic concepts are outlined. It is concluded that CT angiography is promising in studying thoracic vessels in various abnormalities. 相似文献
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执行器失效不确定时滞系统的指定衰减度鲁棒可靠控制 总被引:8,自引:0,他引:8
针对一类含有时变时滞的不确定参数线性系统,研究了在执行器发生故障情况下的鲁棒可靠控制器设计问题.系统中的参数不确定性满足广义匹配条件,时变时滞的大小及其变化率有界,并假设故障执行器元件的输出为零.经过适当的模型变换,将原系统的鲁棒指数镇定问题转化为另一个等价系统的鲁棒镇定问题.根据Lyapunov稳定性理论和线性矩阵不等式(LMI)方法,分别给出了鲁棒可靠控制器存在的时滞无关和时滞相关充分条件.仿真结果表明了该控制器设计方法的有效性. 相似文献
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IE Afthentopoulos S Panduranga Rao R Mathews DG Oreopoulos 《Canadian Metallurgical Quarterly》1998,49(4):251-257
Merkel cell carcinoma (MCC) of the skin is a rare, primary malignant skin neoplasm which can present as a cutaneous nodule. These neoplasms are seen primarily in the elderly and located in the head and neck area or extremities. Twenty-nine aspirates from primary and metastatic lesions obtained by percutaneous fine-needle aspiration in 19 patients have been studied. The cytomorphologic features, clinical information, and immunocytochemical (ICC) findings are detailed. Aspirate smears demonstrated small-to-intermediate-sized cells with a loosely cohesive pattern. Nuclei were round with finely granular chromatin and multiple, small nucleoli. Cells possessed a thin rim of cytoplasm, and infrequent pseudorosette formations were noted in cell groups. ICC results were universally positive for cytokeratin, which showed a paranuclear "dot-like" pattern. Neuron-specific enolase, epithelial membrane antigen, and S-100 protein were positive in varying degrees. Leukocyte common antigen was universally negative. The diagnosis of MCC of the skin by FNA can be made by applying cytologic features in addition to ancillary studies and clinical information. 相似文献
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