共查询到20条相似文献，搜索用时 46 毫秒
1.
本文从“可持续发展”与“教育的可持续发展”的科学内涵出发,对我国高校科技与教育在可持续发展战略中的地位与作用进行了详尽的论述,并针对高校科技工作促进教育适应可持续发展必须解决的问题,提出了自己的建议,从而提高高校自身的竞争力,并责无旁贷地承担起科技促进教育的可持续发展的历史使命。 相似文献
2.
As harvesting effort and yield are increased, animal populations that are being harvested for sustained yield will take longer to recover from environmentally imposed disturbances. One consequence is that the coefficient of variation (the relative variance) of the yield increases as the point of maximum sustained yield (MSY) is approached. When overexploitation has resulted in a population smaller than that for MSY, high effort produces a low average yield with high variance. These observations accord with observed trends in several fish and whaling industries. We expect these effects to be more pronounced for a harvesting strategy based on constant quotas than for one based on constant effort. Although developed in a MSY context, the conclusions also apply if the aim is to maximize the present value of (discounted) net economic revenue. 相似文献
3.
Delayed-type cutaneous hypersensitivity to sheep erythrocytes was induced in rats by intradermal injection of the antigen mixed with Freund's adjuvant; hypersensitivity was sustained by weekly injections. Either passive immunization with rat antiserum to sheep erythrocytes or intravenous injection of sheep erythrocytes partially suppressed induction of hypersensitivity; these procedures used together specifically and completely suppressed induction of hypersensitivity. Complete suppression was sustained by antigen given intravenously before each weekly injection of the mixture of antigen and adjuvant. These findings provide the rational basis of a simple method for prolonging survival of allografts with only the biological agents, antigen and antibody, of the immunological response. 相似文献
4.
Early enhancement of calcium currents by H-ras oncoproteins injected into Hermissenda neurons 总被引：4，自引：0，他引：4
Influx of calcium through membrane channels is an important initial step in signal transduction of growth signals. Therefore, the effects of Ras protein injection on calcium currents across the soma membrane of an identified neuron of the snail Hermissenda were examined. With the use of these post-mitotic cells, a voltage-sensitive, inward calcium current was increased 10 to 20 minutes after Harvey-ras oncoproteins were injected. The effects of oncogenic Harvey ras p21 protein (v-Ras) occurred quickly and were sustained, whereas the effects of proto-oncogenic ras protein (c-Ras) were transient. This relative potency is consistent with the activities of these oncoproteins in stimulating cell proliferation. Thus, this calcium channel may be a target for Ras action. 相似文献
5.
Systemic gamma-aminobutyric acid produces a rapid, sustained, but transiently reversible blockade of evoked axodendritic excitatory postsynaptic potentials in neonatal cortex when the "barrier" operating to restrict its passage has been altered by various experimental procedures. The data obtained under these conditions indicate the existence of well-developed synaptic pathways in the superficial neuropil of immature cortex. 相似文献
6.
[目的]采用家兔耳缘静脉注射法考察尼莫地平缓释制剂对家兔血管刺激性试验。[方法]将家兔分为阴性对照组(生理盐水组)、尼莫地平注射液组和尼莫地平缓释制剂组,分别通过耳缘静脉注射,给药剂量为0.5 mg/kg。[结果]生理盐水组和尼莫地平缓释制剂组没有出现明显的血管刺激现象,而尼莫地平注射液组出现强烈的血管刺激现象。[结论]尼莫地平缓释制剂与原制剂尼莫地平注射液相比,有效降低了家兔血管刺激性,为其临床上广泛应用提供了一定基础。 相似文献
7.
Selective mitochondrial damage by a ruby laser microbeam: an electron microscopic study 总被引：3，自引：0，他引：3
A pulsed ruby laser microbeam produces changes in single living cells stained with a low concentration of Janus green B. Electron micrographs show that such alterations are the result of morphological damage sustained by and restricted to the mitochondria in the irradiated area. 相似文献
8.
FALK JL 《Science (New York, N.Y.)》1961,133(3447):195-196
Marked polydipsia was produced in all animals trained to press a bar for food pellets on a 1-minute variableinterval schedule. It is suggested that since this feeding arrangement produces a sustained, high fluid intake in the normal, unrestrained animal, it might serve as a useful tool in the study of renal function. 相似文献
9.
In normal subjects, hypoglycemia produces an abrupt and sustained rise in levels of human growth hormone in plasma. This effect is independent of insulin, glucagon, or epinephrine. Prolonged fasting is accompanied by a rise in the hormone level in plasma. Measurement of this hormone after induced hypoglycemia is a specific test for pituitary somatotropic function. 相似文献
10.
Craig H 《Science (New York, N.Y.)》1968,159(3810):93-96
Nitrogen isotope fractionation in the Hoering-Moore experiment, injection of N2 into CO2 carrier and flow through sandstone, is due to diffusion in the gas phase rather than to surface interaction. This process, called "carrier diffusion," produces a characteristic fractionation pattern relative to a fraction coordinate, with points of zero fractionation at 16 and 84 percent and heavy isotope enrichment between these points. Carrier diffusion is an efficient enrichment process for low-abundance isotopes lighter than the abundant species and for helium and hydrogen in gas mixtures. 相似文献
11.
Immunosuppressant from group A streptococci 总被引：9，自引：0，他引：9
A cytoplasmic component of group A streptococci suppresses both 19S and 7S antibody responses of mice to sheep erythrocytes. Partial purification is achieved by differential centrifugation and gel filtration. When the direct and indirect hemolytic plaque techniques are used, a single injection of this group A material given before injection of erythrocytes produces more than 90-percent suppression of either primary or secondary immune response. 相似文献
12.
Injection of potassium chloride into the hippocampus produces a disruption of electrical activity; a concomitant of this disruption is a deficit in retention of conditioned suppression learned 24 hours before injection. 相似文献
13.
Anticholinesterase-induced amnesia and its temporal aspects 总被引：1，自引：0，他引：1
Injection of the anticholinesterase drug diisopropyl fluorophosphate into the hippocampi of rats, 30 minutes after escape learning, produces partial amnesia with full recovery 5 days after injection. No such amnesia is produced if the injection takes place 3 days after learning. However, with injections 5 days after learning there is again an effect, and at 14 days amnesia is complete though no normal forgetting occurs within this period. 相似文献
14.
通过多种途径实验感染，评定了分离自关节炎型病鸡病变关节的金黄色葡萄球菌对组织的亲嗜性以及病型与感染门的关系。关节内注射感染引起了典型的关节炎疾病；静脉注射感染除引起脓血症外，尚出现急性化脓性关节炎；皮下或肌肉注射感染均能致局部皮肤坏死、出血和蜂窝组织炎，但一般不致关节炎；气管内、气囊内或嗉囊内感染仅引起局部轻度炎症或不能致病。因而推论，关节炎型葡萄球菌病很可能仅由特定菌株经关节伤口感染才能引起。 相似文献
15.
Injection of d-tubocurarine chloride into certain insects produces complete flaccid paralysis. The site of injection is closely related to the region of primary paralysis. The effect depends on concentration, with distinct differences in the optimum concentrations for various species so far tested. A dose-response curve has been prepared for Calliphora erythrocephala. 相似文献
16.
采用简化的简单生物圈模型（Simplified Simple Biosphere Model,SSiB）与TOPMODEL的耦合模型SSiB／TOPMODEL,进行5种植被类型覆盖下梭磨河流域水量平衡敏感性试验,并在此基础上分析流域植被对流域水量平衡的影响。结果表明,植被覆盖增加了冠层蒸腾和截留蒸发而使土壤蒸发减小。蒸发分量中这2个相反变化的净效应决定了植被的水文效应是增加流域的径流还是减小径流。对于模拟的5种植被类型与裸地相比,流域蒸发均有所减小,而流域径流均有所增加。当流域为草地覆盖时,流域总蒸发最大,为1．2205mm／d,而总径流深最小,为0．6587mm／d;当流域为落叶针叶林覆盖时,流域总蒸发最小,为1．0250mm／d,而总径流深最大,为0．8544mm／d：当流域为常绿针叶林覆盖时,蒸腾和冠层截留蒸发最大,分别为0．383和0．489mm／d。而土壤蒸发,草地覆盖时最大为0．799mm／d,常绿针叶林覆盖时最小为0．243mm／d。 相似文献
17.
Chronic blockade of dopamine D2 receptors, a common mechanism of action for antipsychotic drugs, down-regulates D1 receptors in the prefrontal cortex and, as shown here, produces severe impairments in working memory. These deficits were reversed in monkeys by short-term coadministration of a D1 agonist, ABT 431, and this improvement was sustained for more than a year after cessation of D1 treatment. These findings indicate that pharmacological modulation of the D1 signaling pathway can produce long-lasting changes in functional circuits underlying working memory. Resetting this pathway by brief exposure to the agonist may provide a valuable strategy for therapeutic intervention in schizophrenia and other dopamine dysfunctional states. 相似文献
18.
Intracranial injection of 10 to 75 micrograms of camptothecin, a plant alkaloid that blocks RNA synthesis in eucaryotic cells, blocks incorporation of tritiated uridine into RNA in the goldfish brain. Injection of 10 to 50 micrograms of the drug within 1.5 hours of training results in greatly diminished memory, tested 1 week later. Injection of the drug 5 or 24 hours after training produces no measurable effect on retention of the learned response. 相似文献
19.
Lymphoepithelial tissues of the intestine and differentiation of antibody production 总被引：1，自引：0，他引：1
The antibody response of young rabbits to the injection of killed Brucella abortus was abolished by prior extirpation of intestinal lymphoepithelial tissues combined with lethal xirradiation and reconstitution with rabbit fetal liver cells. Extirpative surgery alone, like lethal x-irradiation and reconstitution without surgery, did not abolish this response. Intestinal lymphoepithelial tissues of rabbits apparently play a central lymphoid function and are responsible for the differentiation of the lymphoid cell line which produces specific antibody and immunoglobulins. 相似文献
20.
(1) It is shown that hypothalamic stimulation in cats, with faradic currents eliciting the syndrome of sham rage, produces after the elimination of the sympathetico-adrenal system a hypoglycemia when the vagi are intact. After bilateral vagotomy the stimulation results in a slight and delayed rise in blood sugar. (2) If in cats in which, due to a sectioning of the spinal cord at the sixth cervical segment, the effect of central discharges on the sympathetico-adrenal system is eliminated, a rage response is elicited by a barking dog it produces a fall in blood sugar. The sectioning of the vagi below the diaphragm abolishes this reaction. From these experiments it is concluded that the normal emotional process as well as the sham rage reaction is characterized by a simultaneous discharge over the vago-insulin and sympathetico-adrenal system. The latter predominates in the normal animal and masks the effects on the former. 相似文献