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21.
在清醒、肌肉麻痹状态下的大鼠,观察到重复电刺激伏核对外侧缰核痛兴奋单位(LHPE)自发放电和痛诱发放电有明显的抑制作用。腹腔注射纳洛酮(6mg/kg体重)可阻断这种抑制作用。而电刺激伏核对外侧缰核痛抑制单位放电有兴奋作用。双侧伏核内微量注射纳洛酮(1.8ug,4min注完)使 LHPE 放电增加,注射吗啡(15ug,4min注完)可抑制 LHPE 放电。本文就以上结果在针刺镇痛中的意义进行了讨论。 相似文献
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The aim of the study was to improve the pre-operative diagnosis of mammary mucinous lesions. All mucinous lesions detected by fine needle aspiration (FNA) and confirmed by histological examination were reviewed by cytological findings, mammographic appearances and sonographic findings. Twenty aspirates had corresponding pathology, including 12 mucinous carcinomas, two mucocele-like lesions (MLL) with atypical ductal hyperplasia, three MLL with ductal hyperplasia and three simple MLL. Simple MLL and mucocele-like with ductal hyperplasia showed scant cellularity, no or rare intact single tumour cells, monolayered arrangement and absence of nuclear atypia. In contrast, most mucinous carcinomas showed higher cellularity, more single tumour cells, three-dimensional clusters, and mild to marked nuclear atypia. However, MLL with atypical ductal hyperplasia showed cytological features overlapping with mucinous carcinoma. MLL had a non-specific mammographic appearance and showed a cystic lesion on sonography. Mucinous carcinoma appeared as a solid mass on sonography and as a distinct nodule on mammography. Based on the combination of FNA cytology and image findings, benign MLL can be correctly distinguished from mucinous carcinoma before surgery. 相似文献
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KAO CY 《The Journal of general physiology》1956,40(1):107-119
Electrical constants of the plasma membrane of the Fundulus egg have been measured with microelectrodes by the transient method. No consistent and significant membrane potential was measured. Membrane capacity averages 0.63 µF/cm.2 for both unactivated and activated eggs. Membrane resistance averages 3450 ohm-cm.2 in the unactivated eggs, but increases 2 to 7 times to an average of 13,290 ohm-cm.2 in the fully activated state. In a hypertonic sucrose solution, the swelling of the egg proper is accompanied by a rapid fall of membrane resistance towards that in the unactivated state. The changes of the membrane resistance are interpreted as probably caused by alterations in the effective pore size in the plasma membrane. 相似文献
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1. A technique is described for recording the bioelectric activity of the squid giant axon during and following alteration of the internal axonal composition with respect to ions or other substances. 2. Experimental evidence indicates that the technique as described is capable of measuring changes in local bioelectric activity with an accuracy of 10 to 15 per cent or higher. 3. Alterations of the internal K+ or Cl- concentrations do not cause the change in resting potential expected on the basis of a Donnan mechanism. 4. The general effect of microinjection of K+ Rb+, Na+, Li+, Ba++, Ca++, Mg++, or Sr++ is to cause decrease in spike amplitude, followed by propagation block. 5. The resting potential decreases when the amplitude of the spike becomes low and block is incipient. 6. The decrease in resting potential and spike amplitude may be confined to the immediate vicinity of the injection. 7. At block, the resting potential decreases up to 50 per cent, but injection of small quantities of divalent cations may cause much larger localized depolarization. 8. The blocking effectiveness of K+, Na+, and Ca++ expressed as reciprocals of the relative amounts needed to cause block is approximately 1:5:100. Rb+ has the same low effectiveness as does K+. Li+ resembles Na+. Ba++ and Mg++ are approximately as effective as Ca++. 9. Microinjection of Na+ may cause marked prolongation of the spike at the injection site as well as decrease in its amplitude. 10. The anions used (Cl-, HCO3-, NO3-, SO4-, aspartate, and glutamate) do not seem to exert specific effects. 11. A tentative explanation is offered for the insensitivity of the resting potential to changes in the axonal ionic composition. 12. New data are presented on the range of variation, in a large sample, of the magnitude of the resting potential and spike amplitude. 相似文献
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Heterozygosity for missense mutations (N88S/S90L) in BSCL2 (Berardinelli–Seip congenital lipodystrophy type 2)/Seipin is associated with a broad spectrum of motoneuron diseases. To understand the underlying mechanisms how the mutations lead to motor neuropathy, we generated transgenic mice with neuron-specific expression of wild-type (tgWT) or N88S/S90L mutant (tgMT) human Seipin. Transgenes led to the broad expression of WT or mutant Seipin in the brain and spinal cord. TgMT, but not tgWT, mice exhibited late-onset altered locomotor activities and gait abnormalities that recapitulate symptoms of seipinopathy patients. We found loss of alpha motor neurons in tgMT spinal cord. Mild endoreticular stress was present in both tgMT and tgWT neurons; however, only tgMT mice exhibited protein aggregates and disrupted Golgi apparatus. Furthermore, autophagosomes were significantly increased, along with elevated light chain 3 (LC3)-II level in tgMT spinal cord, consistent with the activation of autophagy pathway in response to mutant Seipin expression and protein aggregation. These results suggest that induction of autophagy pathway is involved in the cellular response to mutant Seipin in seipinopathy and that motoneuron loss is a key pathogenic process underlying the development of locomotor abnormalities. 相似文献
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Cheng CY Wong EW Lie PP Mruk DD Xiao X Li MW Lui WY Lee WM 《Histology and histopathology》2011,26(11):1465-1474
In mammalian testis, spermatogenesis takes place in the seminiferous epithelium of the seminiferous tubule, which is composed of a series of cellular events. These include: (i) spermatogonial stem cell (SSC) renewal via mitosis and differentiation of SSC to spermatogenia, (ii) meiosis, (iii) spermiogenesis, and (iv) spermiation. Throughout these events, developing germ cells remain adhered to the Sertoli cell in the seminiferous epithelium amidst extensive cellular, biochemical, molecular and morphological changes to obtain structural support and nourishment. These events are coordinated via signal transduction at the cell-cell interface through cell junctions, illustrating the significance of cell junctions and adhesion in spermatogenesis. Additionally, developing germ cells migrate progressively across the seminiferous epithelium from the stem cell niche, which is located in the basal compartment near the basement membrane of the tunica propria adjacent to the interstitium. Recent studies have shown that some apparently unrelated proteins, such as polarity proteins and actin regulatory proteins, are in fact working in concert and synergistically to coordinate the continuous cyclic changes of adhesion at the Sertoli-Sertoli and Sertoli-germ cell interface in the seminiferous epithelium during the epithelial cycle of spermatogenesis, such that developing germ cells remain attached to the Sertoli cell in the epithelium while they alter in cell shape and migrate across the epithelium. In this review, we highlight the physiological significance of endocytic vesicle-mediated protein trafficking events under the influence of polarity and actin regulatory proteins in conferring cyclic events of cell adhesion and de-adhesion. Furthermore, these recent findings have unraveled some unexpected molecules to be targeted for male contraceptive development, which are also targets of toxicant-induced male reproductive dysfunction. 相似文献
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单克隆抗体(monoclonal antibody, m Ab),指同一种抗原决定簇的细胞克隆所产生的均一性抗体。m Ab已成功应用以诊疗各种疾病,尤其是癌症和免疫性疾病。近些年来,m Ab逐渐用于治疗病毒性疾病,针对急性和慢性病毒感染研发的抗病毒m Ab数量逐渐增长。m Ab的组合疗法可同时靶向病毒多个表位,从而克服病毒免疫逃逸的问题,多价m Ab的设计开发能够更加有效的作用于病毒。本文比较了不同m Ab制备方法的优缺点,总结了m Ab近期在抗病毒感染领域的研究进展,并讨论了m Ab作为治疗病毒性疾病药物的前景。 相似文献
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