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51.
本文应用电力载波技术,实现远端时钟的中央控制。系统通过电力载波芯片从电力线上收发控制信号,中央控制端发送的时钟校准信号到电力线网络,接人网络的远端时钟接收到校准信号后,由微处理器解析数据调整受控端时钟显示,从而实现时钟的中央控制。  相似文献   
52.
Uncertainties remain as to whether breastfeeding is protective against childhood allergic disorders. Positive relationships of breastfeeding with asthma and atopic eczema were observed in two previous Japanese studies. This cross-sectional study investigated the association between the feeding pattern after birth and the prevalence of allergic disorders during the past 12 months in Japanese schoolchildren. Study subjects were 24,077 children aged 6-15 yr in Okinawa. The outcomes were based on diagnostic criteria from the International Study of Asthma and Allergies in Childhood. Allowance was made for age, sex, number of siblings, smoking in the household, paternal and maternal history of asthma, atopic eczema, and allergic rhinitis, and paternal and maternal educational level. Breastfeeding, regardless of exclusivity, for 13 months or longer and exclusive breastfeeding for 4-11 months were independently associated with a higher prevalence of atopic eczema, particularly among children without a parental allergic history. A clear positive dose-response relationship was observed between prolonged duration of breastfeeding, regardless of exclusivity, but not exclusive breastfeeding, and the prevalence of atopic eczema. We found a significant positive trend for atopic eczema across the three categories (formula milk, partial and exclusive breastfeeding) in the first 4 months of life although the odds ratio for exclusive breastfeeding was not statistically significant. No material association was found between the feeding pattern after birth and the prevalence of wheeze or allergic rhinoconjunctivitis. Prolonged breastfeeding may be associated with a higher prevalence of atopic eczema in Japanese children.  相似文献   
53.
A direct solution is proposed to an optimal control problem of linear econometric systems with a quadratic welfare loss function when there are linear equality constraints on the control variables. The direct solution proposed here eliminates the problem of non-uniqueness of the optimal solution, which is present when this optimal control problem is solved using the recursive algorithm proposed by Chow,1 Pindyck2 and Tan.3 If a unique solution to the optimal control problem exists, then the direct solution and the recursive solution coincide.  相似文献   
54.
颅面部的 CT扫描检查主要包括颅脑面部上、下颌骨、中耳、内耳、鼻窦、眼眍、眼球及颞骨茎突等部位的扫描检查 ,上述部位的扫描检查的位置的摆法 ,层面的厚度、间距 ,扫描时间及螺距等参数的选择及扫描后图像的后处理工作对检查结果的诊断至关重要。上述参数任意一个选择不当及  相似文献   
55.
56.
This paper examines delinquency as it relates to family influences.  相似文献   
57.
The work situation of 66 male patients who underwent elective coronary artery bypass surgery (CABS) and who had been randomly allocated to receive cardiac rehabilitation (group R) was compared with the work situation of 59 similar patients allocated to receive only standard care (group H). The follow-up time was one year. The proportions of subjects working in groups R and H were 26% and 20% (p=ns) before the CABS, 45% and 34% (p=ns) 6 months and 56% and 38% (p=ns) 12 months after the CABS, repectively. The increase in proportion of subjects who worked was significant in both groups at both 6 and 12 months after the CABS (p<0.05 for all changes). The increases were not significantly different between the whole groups, but in patients younger than 55 years of age, return to work was more frequent in group R than in group H (at 12 months 60% vs. 35%, p for the difference in change=0.02). Stepwise logistic regression analysis of the factors influencing return to work showed that a patient's judgement of his own working capacity as good 6 months after CABS (odds ratio (OR) 8.5, confidence interval (CI) 2.3–32.0), functional class 16 months after the CABS (OR 6.7, CI 1.8–24.5), his desire to work (OR 6.4, CI 1.6–26.0) and absence from work of less than 3 months before the CABS (OR 4.9, CI 1.2–20.2) were significant positive predictors of return to work 1 year after the CABS.  相似文献   
58.
均一吸收体中SPECT重建多解性的探讨   总被引:1,自引:0,他引:1  
通过对重建图像噪声特性的分析,间接证明SPECT的解具有多样性。分别用TretiakMetz、Gulberg、富谷武浩等推导的3种等价重建方法和Belini等推导的重建方法,经计算机模拟重建衰减均匀分布的图像,先预置相同的重建图像的空间分辨率,再比较它们的噪声特性。两种方法重建图像的噪声分布:前者近图像边缘时增大,而后者减小,从而间接证明在假定均匀衰减条件下,SPECT的重建有多解性。  相似文献   
59.
The primary objectives of this study were to determine the maximum tolerated dose (MTD) of paclitaxel administered by 3-h infusion to patients with solid tumors, and to characterize the pharmacokinetics of a 3-h infusion in comparison with those of a 24-h infusion. Twenty-seven patients each received one of six levels of paclitaxel, 105, 135, 180, 210, 240 and 270 mg/m2, with premedication. Two patients given 240 mg/m2 and one patient given 270 mg/m2 unexpectedly had grade 3/4 hypotension just after finishing the paclitaxel infusion. Peripheral neuropathy was also dose-limiting at 270 mg/m2. Although granulocytopenia was significantly less severe than with a 24-h infusion, more than half of the patients experienced grade 4 toxicity at doses of 240 or 270 mg/m2. Severe hypersensitivity reactions (HSRs) were not observed. Pharmacokinetic studies using high performance liquid chromatography demonstrated proportionally greater increases in the peak plasma concentration and area under the curve, and decreases in clearance and volume of distribution with increasing dose, suggesting non-linear pharmacokinetics of paclitaxel when given by 3-h infusion. The MTD of paclitaxel given as a 3-h infusion was determined to be 240 mg/m2 with dose-limiting toxicities of granulocytopenia, peripheral neuropathy and hypotension. Hypotension just after infusion, induced by 3-h infusion of paclitaxel, is a new observation which has not been reported previously. The recommended dose for phase II study is 210 mg/m2. Although hypotension was observed as an unexpected toxic effect, paclitaxel could be administered safely over 3 h with premedication and proper monitoring, resulting in reduced myelotoxicity and with no increase in the incidence of HSRs as compared with a 24-h infusion.  相似文献   
60.
Cerebral blood flow and glucose utilization were measured in rat neocortex, hippocampus and striatum following methylenedioxymethamphetamine injection (5 mg/kg, i.v.), using the tracers [14C]iodoantipyrine and [14C]2-deoxyglucose, respectively. In control rats, blood flow was coupled to glucose metabolism, but in methylenedioxymethamphetamine-treated rats, marked hyperperfusion was measured in frontal and parietal cortex with no change in glucose use. This suggests that methylenedioxymethamphetamine has the potential to disrupt cerebrovascular control.  相似文献   
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