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71.
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G. M. Howard T. V. Nguyen N. A. Pocock P. J. Kelly J. A. Eisman 《Osteoporosis international》1997,7(3):190-194
Calcaneal ultrasound has been increasingly studied for its potential in the assessment of osteoporotic fracture risk. The accuracy of such an assessment is, in part, dependent on the reproducibility of the measurement. This study examines the impact of handedness on ultrasound measurements [broadband ultrasound attenuation (BUA) and velocity of sound (VOS)] in the calcaneus. Two hundred and sixty-four subjects (57 men and 297 women) aged 51.1+13.6 years (mean ± SD) were studied. For each subject, calcaneal ultrasound measurements were performed on both heels with a McCue CUBA ultrasound densitometer. Right-handed dominance (94.7%) was determined by structured interview. In men, BUA measurements were significantly higher on the dominant side: mean difference 4.1±1.5 dB/MHz (mean ± SD;p=0.009), equivalent to 4.2+1.5% and more than 4 times the average rate of annual change in BUA. The difference between sides was greater in young (<50 years) than old men (>50 years). Among the women, the difference was not statistically significant (0.7±0.9 dB/MHz;p=0.4); however, it was significant in younger women (20–30 years) (99±4 vs 90±4 dB/MHz,p=0.01). By contrast VOS did not differ between sides in either men or women irrespective of age. Within-subject standard deviation of BUA was 9.8 dB/MHz for men and 8.6 dB/ MHz for women and the component due to right and left difference was 8.4 dB/MHz for men and 6.9 dB/MHz for women. This variability of BUA between right and left heels could increase the false-positive rate by up to 28% for a cut-off of 2 SD below the mean. These data indicate that variation between left and right heel measurements of BUA is higher than that of random error measurements, particularly in men and younger, presumably more physically active subjects. Although VOS measurements were not side dependent, in the smaller number of studies examining VOS and fracture risk, VOS appears to have a weaker predictive power than BUA. Clinical and epidemiological studies involving calcaneal BUA measurements should standardize the side measured to either the dominant or non-dominant heel, to reduce within-subject variation and increase their power. 相似文献
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用神经网络法预测药物在体透过人皮肤的渗透性 总被引:4,自引:2,他引:2
傅旭春 《浙江大学学报(医学版)》2003,32(2):152-154,158
目的:预测药物在体透过人皮肤的渗透性。方法:以正辛醇/水分配系数(logP)、分子体积(V)、氢键酸度(∑β2^H)和氢键碱度(∑β2^H)等理化参数作为输入层神经元,以药物在一定时间内在体透过人皮肤的透过比的对数值(R,透过量/未透过量)作为输出层神经元,建立起合适的BP(Back—propagation)神经网络。结果:17个药物在一定时间内在体透过人皮肤的透过比的神经网络计算值和实测值均相当符合。结论:用BP神经网络法可以较好地预测药物在体透过人皮肤的渗透性。 相似文献
76.
结合国外图书馆网上实时参考咨询服务的研究与试验情况,详细阐述和分析了基于实时的虚拟参考咨询系统的功能和设计策略. 相似文献
77.
MDFrank A. Liporace MDKenneth Egol MDKenneth J. Koval 《Operative Techniques in Orthopaedics》2002,12(2)
Hip fractures have been one of the most studied injury pattern in adults. The number of hip fractures is increasing exponentially; furthermore, the cost of treatment places great economic strain on society. There have been recent developments in hip-fracture treatment, particularly involving the intertrochanteric region, with emphasis on deformity prevention to try to optimize patient functional outcomes. In this article, we outline some of these developments with an emphasis on changes in implant design. 相似文献
78.
W/O/W型甘草酸单铵盐口服复乳的处方设计及其理化特性研究 总被引:2,自引:0,他引:2
采用均匀设计,以乳剂的稳定性参数为考察指标,考察了初乳乳化剂、复乳乳化剂、乳化时间等因素对复乳稳定性的影响;筛选出W/O/W型甘草酸单铵盐口服复乳的优化处方和工艺,并对复乳的主要理化特性和物理稳定性进行了考察。 相似文献
79.
A microcapsule form of nitrofurantoin was prepared by a simple coacervation method with carboxymethylcellulose and aluminium sulfate. 33 factorial design was performed for three independent variables, namely, the particle size of the drug, the size of the microcapsules and the pH of the dissolution medium. The dissolution tests with the formulated microcapsules were carried out according to the United States Pharmacopeia XXII rotating basket method at pH 1.2, 5 and 7.5, which represent the pH of gastrointestinal fluids. Release data were examined kinetically and the ideal kinetic models were estimated and t
63.2 values obtained from RRSBW distribution were used in the factorial design experiment. The influence of the independent variables on the dissolution of nitrofurantoin microcapsules could be expressed as the pH of the dissolution medium > particle size of the microcapsule > particle size of nitrofurantoin. The other aim of this study was to evaluate microcapsule formulation in terms of the United States Pharmacopeia criteria with a minimum of experiments. Our findings suggest that dosage forms which comply with the pharmacopoeia criteria for dissolution can be prepared and selected by factorial design. 相似文献
80.
Abstract. Objectives. To evaluate the efficacy of self-administered subcutaneous sumatriptan in the acute treatment of early-morning migraine attacks. Design. A double-blind, randomized, placebo-controlled, cross-over study. Setting. Thirteen neurology centres in France. Subjects. Patients of either sex, 18–65 years old, with two to six attacks of migraine (according to the International Headache Society (IHS) criteria, with or without aura) per month, of which at least two had to be early-morning migraine attacks. One-hundred-and-one patients were included, 96 being evaluable for the first attack and 81 for the cross-over design. Interventions. Two migraine attacks (grade 2/3) were treated with sumatriptan (6 mg) or placebo, with an optional second injection 1–24 h later. Main outcome measures. The primary end-point was headache relief: reduction in headache severity from grade 2/3 (moderate/severe) to grade 1/0 (mild/none) 2 h after treatment. Results. Sumatriptan was superior to placebo for headache relief (32 [78%] vs. 11 [28%] at the first attack; 29 [73%] vs. 8 [20%] at the second; P < 0.001). Because of a significant carry-over effect for some of the secondary end-points, a parallel-group analysis of the first attack was performed, which confirmed a significantly higher efficacy of sumatriptan for all end-points: pain-free rate (22 [46%] vs. 7 [15%]; P = 0.001) and use of a second injection (26 [53%] vs. 38 [81%]; P = 0.004). Sumatriptan was preferred by 74% of patients vs. 17% for placebo, and 9% expressed no preference (P < 0.0001). After complete relief, headache reappeared in 8/23 (35%) patients with sumatriptan and 3/7 (43%) with placebo. Adverse events were significantly more frequent with sumatriptan but they were minor and transient. Conclusion. Subcutaneous sumatriptan auto-injection is an effective and well-tolerated acute treatment of early-morning migraine attacks allowing earlier return to normal activity. 相似文献