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971.
972.
Bone mineral density (BMD, g/cm2) was measured using dual-photon absorptiometry (DPA) in selected areas of the proximal tibia following uncemented PCA knee prosthesis. In nine patients with 14 alloplastic operations, measurements were taken at 3-6-month intervals for the first 3 1/2 years after operation. There was a significant increase in BMD of about 15% during the first 6 months after operation. The following year it remained increased, although not significantly, compared with the initial values, then gradually diminished. Increased bone density after arthroplasty may be explained mainly by stimulation of bone formation from weight bearing due to improved walking ability. Stress shielding of the proximal part of the supporting tibial bone did not seem to occur.  相似文献   
973.
A case of hemianaesthesia caused by right hemisphere stroke was found to have good sensitivity and cutaneous localisation when she touched her impaired hand with her good contralateral hand or with a probe held by that hand. The capacity did not depend solely upon movement or positioning of her right arm, and she could also discriminate whether her own left fingers, as opposed to someone else's inter-digitated fingers, were being touched, but only when she did the touching. Thus, the threshold of the impaired hand appeared to be markedly affected by active involvement of the contralateral limb in delivering the stimulus.  相似文献   
974.
Acute pulmonary hypertension was caused by inhalation of 5% 02 in rats. Pulmonary vascujar re- sistance (PVR) increased, but heart rate (HR), cardiac output (CO) and carotid arterial pressure (CAP) were not obviously changed. After an intravenous admini- stration of Radix Angelicae sinensis, the acute pulmonary hypertension induced by inhalation of 5% O2 could be attenuated, but this effect disappeared if propranolol was given before Radix Angelicae sinensis. In chronic experiments, the same results were obtained, but the protective effect of Radix Angelicae sinensis on heart function was not influenced by propranolol. It is suggested that Radix Angelicae sinensis rmght play a role by stimulating the βz-receptor in the prevention of acute and chronic hypoxic pulmonary hypertension. However, prevention of hypertrophy of the right ventricle and enhancement of heart function in chronic hypoxic rats might not be attributed to the β1 receptor in the heart.  相似文献   
975.
作者用恒温加速试验法研究了维生素B_(12)注射液的稳定性。结果表明:该注射液的稳定性在pH值4.80左右较好,加络合剂可增加其稳定性,有效期为5年。  相似文献   
976.
977.
白马藏人是一支有待识别的民族。本文以肤纹作聚类分析,结果表明白马藏人与藏族的距离很大,很有可能是一支独立的民族。  相似文献   
978.
为探讨构效关系,合成了1-对氟苯基-6-氟-1,4-二氢-4-氧-7-(1-哌嗪)噌啉-3-羧酸及其喹啉、萘啶、吡啶[2,3-C]哒嗪环系类似物16个。测定了对大肠杆菌的MIC。用Hückel分子轨道理论(HMO)方法计算了四个母体环上电子密度。结果表明:环中氮的位置对药效团——3位羧基和4位羰基氧原子上电子密度的影响较大而影响其抗菌活性。喹啉、萘啶两环系的3位羧基和4位羰基氧原子上的电子密度较高,其体外抗菌活性较高;而噌啉及吡啶[2,3-C]哒嗪两环系的电子密度较低,其体外抗菌活性较低甚至消失。  相似文献   
979.
An artificial rearing procedure was used to expose neonatal rats to a formula containing 3.74% ethanol during postnatal days 4 through 10. This treatment produced a mean blood ethanol concentration of 379.8 +/- 17.3 mg/dl. When the pups were killed on the afternoon of postnatal day 10, brain weight to body weight ratio in the ethanol-exposed rats was reduced 22.4% and 21.5% compared to suckle and pair-fed controls, respectively. Ethanol exposure also resulted in a 16% reduction of neurons in hippocampal field CA4, compared to controls, but did not produce deficits in fields CA1 or CA3. There was also a 10% increase in the number of neurons (a population of cells in the midst of a proliferative phase at the time of the exposure) in the granule cell layer of the dentate gyrus. The ethanol exposure did not affect cell size in any of the four neuron populations measured. These results suggest, that within the dose and timing parameters examined, ethanol exposure during the third trimester equivalent appears to be preferentially harmful to specific populations of developing neurons.  相似文献   
980.
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