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1.
This paper investigates the relationship between physical activity and depressed mood, under conditions of family conflict. We analyze data from a representative sample of 7232 Icelandic adolescents. Analysis of variance was carried out to test for main and interaction effects. The study shows that while family conflict increases the likelihood of depressed mood, among adolescents, physical activity decreases the likelihood of depressed mood. Furthermore, physical activity plays a more important role among those adolescents living in aversive circumstances, than other adolescents, as family conflict and physical activity interact in the effect on depressed mood for adolescents living in such circumstances. The findings highlight the role of physical activity in decreasing mental distress among adolescents, especially those living in aversive circumstances at home.  相似文献
2.
Several studies performed in outbred Roman high- and low-avoidance lines (RHA and RLA, respectively) have demonstrated that the more anxious line (RLA) is characterized by a higher hypothalamic-pituitary-adrenal (HPA) response to certain stressors than the less anxious one (RHA). However, inconsistent results have also been reported. Taking advantage of the generation of an inbred colony of RLA and RHA rats (RHA-I and RLA-I, respectively), we have characterized in the two strains not only resting and stress levels of peripheral HPA hormones but also central components of the HPA axis, including CRF gene expression in extra-hypothalamic areas. Whereas resting levels of ACTH and corticosterone did not differ between the strains, a greater response to a novel environment was found in RLA-I as compared to RHA-I rats. RLA-I rats showed enhanced CRF gene expression in the paraventricular nucleus (PVN) of the hypothalamus, with normal arginin-vasopressin gene expression in both parvocellular and magnocellular regions of the PVN. This enhanced CRF gene expression is not apparently related to altered negative corticosteroid feedback as similar levels of expression of brain glucorticoid and mineralocorticoid receptors were found in the two rat strains. CRF gene expression tended to be higher in the central amygdala and it was significantly higher in the dorsal region of the bed nucleus of stria terminalis (BNST) of RLA-I rats, while no differences appeared in the ventral region of BNST. Considering the involvement of CRF and the BNST in anxiety and stress-related behavioral alterations, the present data suggest that the CRF system may be a critical neurobiological substrate underlying differences between the two rat strains.  相似文献
3.
Spontaneous pain following spinal nerve injury in mice   总被引:1,自引:0,他引:1  
Autotomy behavior is frequently observed in rats and mice in which the nerves of the hindlimb are severed, denervating the paw. This is the neuroma model of neuropathic pain. A large body of evidence suggests that this behavior reflects the presence of spontaneous dysesthesia and pain. In contrast, autotomy typically does not develop in partial nerve injury pain models, leading to the belief that these animals develop hypersensibility to applied stimuli (allodynia and hyperalgesia), but not spontaneous pain. We have modified the widely used Chung (spinal nerve ligation [SNL]) model of neuropathic pain in a way that retains the fundamental neural lesion, but eliminates nociceptive sensory cover of the paw. These animals performed autotomy. Moreover, the heritable across strains predisposition to spontaneous pain behavior in this new proximal denervation model (SNN) was highly correlated with pain phenotype in the neuroma model suggesting that the pain mechanism in the two models is the same. Relative reproducibility of strain predispositions across laboratories was verified. These data indicate that the neural substrate for spontaneous pain is present in the Chung-SNL model, and perhaps in the other partial nerve injury models as well, but that spontaneous pain is not expressed as autotomy in these models because there is protective nociceptive sensory cover.  相似文献
4.
The recent discovery of TPH-2, a new isoform of tryptophan hydroxylase, the enzyme that catalyses the transformation of tryptophan into 5-hydroxytryptophan and the rate-limiting step in brain serotonin (5-HT) biosynthesis, has boosted new interest in the many functions of 5-HT in the brain and non-nervous tissues. Recent studies on TPH-2 are reviewed with particular attention to the role of this enzyme in behavior and in response to drugs as assessed by comparing strains of mice carrying a functional polymorphism of TPH-2. Most studies concur to indicate that 5-HT synthesis through TPH-2 influence nervous tissues whereas TPH-1 is responsible for the synthesis and action of 5-HT in peripheral organs. Partial impairment of brain 5-HT synthesis caused by polymorphism of the gene encoding TPH-2 causes reduced release of the neurotransmitter, increased aggressiveness, and alters the response to drugs inhibiting the reuptake of 5-HT. Strain comparison might be a useful strategy to investigate the genotype-dependent alterations of TPH-2.  相似文献
5.
Summary The Schmidt-Ruppin strain of Rous sarcoma virus has been shown to induce neuroectodermal and mesenchymal tumors of the brain of inbred CDF Fischer rats. The inoculation of 105 FFU of virus into the cerebrum of 2 day old rats was followed by 96% incidence of tumor growth after a latency period of 3 months. Twenty-four of twenty-five inoculated animals developed tumors, all of which were primary intracerebral neoplasms. They fell into three main groups: gliomas 60%, sarcomas 31%, gliosarcomas 9%. Of the 34 gliomas induced, 28 (84%) were astrocytic, and there was one oligodendroglioma, 2 mixed gliomas, and 3 ependymoma-like tumors. The advantages of this brain tumor model are a high glioma incidence, and a short induction time in a commercially available strain of inbred Fischer rats previously shown to be susceptible to the neuro-oncogenic action of resorptive chemical carcinogens.Supported by fellowships of the Max-Planck-GesellschaftUSPHS Grant CA-11898  相似文献
6.
Summary Lewis and PVG strains of rats and their F1-hybrids were challenged with guinea-pig or bovine encephalitogenic protein (EP) in Freund's complete adjuvant (FCA) to produce experimental allergic encephalomyelitis (EAE). The Lewis and F1-rats were also challenged with guinea-pig EP in FCA with a fivefold lower concentration of Mycobacterium butyricum. Data are presented concerning clinical signs und histological changes of EAE showing an intermediate position of susceptibility to EAE for the F1-hybrids compared to the parental strains. The findings are discussed in relation to the mode of inheritance of susceptibility of EAE. Among rats immunized with bovine encephalitogenic protein in FCA a weak activity was registered; this was difficult to evaluate, as it could be an effect of FCA only.Abbreviations EAE Experimental allergic encephalomyelitis - EP Encephalitogenic protein - FCA Freund's complete adjuvant  相似文献
7.
Summary Adult NMRI mice were inoculated intracerebrally with 1.5–5×102 pfu of the neurovirulent strain Ma1 of vaccinia virus. The animals usually became diseased on day 3 and died on day 5 or 6 p.i. Infectivity assay studies on the mouse brains yielded a steeply rising viral titer comparable with that exhibited by several other so-called neurovaccinia strains after intracerebral inoculation. Histological studies revealed a patchy leptomeningitis most apparent over the basal brain surface. Mononuclear elements of varied size were the most common infiltrate cells in the meningitic lesions. These often showed a pronounced hemorrhagic and necrotizing character. In some places, the cellular infiltrates within the subarachnoid space extended along the perforating vessels into the superficial cerebral cortex. By electron microscopy, all essential stages of virus morphogenesis including the discharge of mature virions could be seen in numerous mononuclear phagocytes and adventitial cells. In contrast to this, no unequivocal neuroectodermal cell showed morphologic evidence of productive viral infection. Likewise, no endothelia or vascular myocytes were encountered which contained newly formed virus particles. However, alterations of the walls of blood vessels and signs of disturbed vascular permeability were a frequent finding in the meningeal foci of inflammation as well as in and around the track left by the inoculating needle. Another ultrastructural feature of the meningitic lesions was the widespread occurrence of degenerating or disintegrating infiltrate cells both infected and uninfected ones.The virologic and morphologic findings observed in this model of experimental vaccinia virus meningo-encephalitis are discussed with regard to data previously published by other authors. The propensity of strain Ma1 of vaccinia virus (and most probably of other so-called neurovaccinia strains) for replication in mesenchymal cells in particularly emphasized.  相似文献
8.
Summary Eighty newborn C3H/BifB/Ki strain mice received a single intraocular inoculation of 0.002–0.003 ml of 108.0 TCID 50/0.1 ml human adenovirus 12 (Ad 12), within 24 h after birth. Forty mice survived and in seven of these (17.5%) a solid retinoblastoma-like neoplasm developed between 64 and 236 days. The tumors have been successfully cultured and also transplanted subcutaneously into syngeneic hosts. Morphologically, all tumors revealed characteristic features of retinoblastoma associated with the Homer Wright type of rosettes. Bizarre giant cells were commonly detectable. Ad 12-specific T-antigens were demonstrated in both the primary and cultured tumor cells using immunofluorescent techniques. Some giant cells also showed numerous T-positive filaments. Electron microscopy disclosed poorly differentiated unipolar cells possessing a large ovoid nucleus. Many tumor cells appeared to contain a well organized solitary cilium consisting of a typical ring of nine doublets with no axial pair (9+0) in close association with a pair of centrioles. Some multinucleated giant tumor cells also contained multiple cilia-centriole complexes within their broad syncytial cytoplasm. Occasional endogenous C particle-like virions unique to murine neuroblastomas were observed for the first time in virus-induced retinal tumors. This unprecedented tumor model in a pure strain mouse adds to the range of known animals sensitive to Ad 12 oncogenesis.This work was supported in part by PHS research grant EY-01667 from the U.S. National Eye Institute (Dr. Mukai), grants from the Retina Research Foundation, Houston, Texas, U.S.A. (Dr. Mukai), the Massachusetts Lions Eye Research Inc., Research to Prevent Blindness, Inc., New York, and Fight for Sight, Inc., New York (Dr Nakajima)  相似文献
9.
The endogenous phosphorylation of membrane-bound proteins was studied in preparations from the cerebral cortex of rats sacrificed by immersion in liquid nitrogen or by decapitation. Compared to quick-frozen rats, samples from decapitated animals demonstrated a two-fold increase in 3 2P-phosphate incorporation into specific protein bands with apparent molecular weights of 56K, and 52K (designated E1 and E2) and a decreased incorporation into a phosphoprotein of 47K (designated F). The phosphorylation of two proteins (78K and 34K) in membranes from decapitated rats was found to be highly stimulated by exogenously added cyclic AMP. On the other hand, the phosphorylation of specific protein bands in preparations from quick frozen rats was minimally affected by addition of cyclic AMP. The results indicate that conditions which lead to increases in cyclic AMP levels in the brain in situ induce specific changes in phosphorylative activity, and these can be detected by assaying isolated membrane fragments in vitro.  相似文献
10.
Summary Thirteen cases of CNS hemangioblastoma were examined with the immunoperoxidase technique for glial fibrillary acidic protein (GEAP) to determine if there were astrocytic elements among the stromal cells of these tumors.In six cases, including two leptomeningeal hemangioblastomas, none of the stromal cells were positive on GFAP stain. Seven cases, however, showed variable presence of GFAP positive cells, including clusters of heavily lipidized cells deep within cerebellar hemangioblastomas. These GFAP positive cells were indestinguishable by other stains from interstitial or stromal cells.Thus, it appears that in at least some hemangioblastomas of the CNS parenchyma, a few or many stromal cells are lipidized astrocytes. All stromal cells, however, cannot be of astrocytic origin, as proposed by Jakobiec et al. (1976), in view of our six cases where no GFAP-positive cells were found in the tumors.It is suggested that cells identified as stromal cells of hemangioblastomas on light microscopy are a heterogeneous group of cells including astrocytic as well as other elements and that they resemble each other on ordinary stains because of the equalizing effect of cell lipidization.  相似文献
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