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Caliş I Kirmizibekmez H Tasdemir D Sticher O Ireland CM 《Zeitschrift für Naturforschung. C, Journal of biosciences》2002,57(7-8):591-596
From the methanolic extract of the underground parts of Globularia orientalis, a new antioxidant sugar ester was isolated. The structure of the new compound, globularitol (1), was identified as 6-O-feruloyl-beta-D-glucopyranosyl-(1-->6)-glucitol by spectroscopic methods (1D and 2D NMR, ESI- and FAB-MS) and confirmed by chemical means. 相似文献
33.
To evaluate whether bombesin treatment has a facilitatory effect on the healing of chronic gastric ulcer, following the induction of ulcer by serosal application of acetic acid, rats were given bombesin (30 microg/kg/day; subcutaneously) or vehicle three times a day for 7, 14 or 21 days until they were decapitated. Neither food intake nor gastric emptying rate in either vehicle-treated or bombesin-treated groups was not statistically different from control rats. Similarly, ulcer indices and gastric myeloperoxidase (MPO) activities at the first and second weeks of injury were not different among the groups. However, in the 3-week ulcer group, bombesin treatment reduced tissue MPO level significantly back to control levels. Moreover, the analysis of the surface epithelium by scanning electron and light microscopy demonstrated a significant reduction in the severity of ulcers by bombesin treatment. Pretreatment with CCK antagonists (L-364,718 or L365,260; 25 micromol/kg/day) before bombesin treatment showed that neither of the CCK antagonists had a significant effect on the bombesin-mediated healing process, suggesting that CCK receptors are not involved in the action of bombesin. In accordance with the previous studies that show its acute gastroprotective effects, bombesin is also effective in promoting the healing process of chronic gastric ulcer in rats. 相似文献
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Arabidopsis CROOKED encodes for the smallest subunit of the ARP2/3 complex and controls cell shape by region specific fine F-actin formation 总被引:7,自引:0,他引:7
Mathur J Mathur N Kirik V Kernebeck B Srinivas BP Hülskamp M 《Development (Cambridge, England)》2003,130(14):3137-3146
The generation of a specific cell shape requires differential growth, whereby specific regions of the cell expand more relative to others. The Arabidopsis crooked mutant exhibits aberrant cell shapes that develop because of mis-directed expansion, especially during a rapid growth phase. GFP-aided visualization of the F-actin cytoskeleton and the behavior of subcellular organelles in different cell-types in crooked and wild-type Arabidopsis revealed that localized expansion is promoted in cellular regions with fine F-actin arrays but is restricted in areas that maintain dense F-actin. This suggested that a spatiotemporal distinction between fine versus dense F-actin in a growing cell could determine the final shape of the cell. CROOKED was molecularly identified as the plant homolog of ARPC5, the smallest sub-unit of the ARP2/3 complex that in other organisms is renowned for its role in creating dendritic arrays of fine F-actin. Rescue of crooked phenotype by the human ortholog provides the first molecular evidence for the presence and functional conservation of the complex in higher plants. Our cell-biological and molecular characterization of CROOKED suggests a general actin-based mechanism for regulating differential growth and generating cell shape diversity. 相似文献
36.
Time-dependent changes in superoxide dismutase, catalase, xanthine dehydrogenase and oxidase activities in focal cerebral ischaemia 总被引:2,自引:0,他引:2
Time-dependent changes in the activities of antioxidant enzymes and an oxidant enzyme, xanthine oxidase (XO), were detected in primary and peri-ischaemic brain regions during permanent occlusion of the middle cerebral artery (MCAO) in rats. There were no changes in superoxide dismutase (SOD) and catalase (CAT) activities after 3 h of MCAO, whereas antioxidant enzyme activities decreased significantly in ischaemic brain areas following 24 h of ischaemia. After 48 h, the enzyme activities returned to the baseline but then a further increase was observed in ischaemic brain areas by 72 h post-ischaemia. Normally, XO exists as a dehydrogenase (XD), but it is converted to XO which contributes to injury in some ischaemic tissues. The XO activity increased slightly at 3 h after ischaemia, but after 24 h of ischaemia it returned to the baseline and then remained relatively unchanged in ischaemic areas. Pretreatment with allopurinol before ischaemia prevented changes in SOD and CAT activities and attenuated brain oedema during 24 h of ischaemia. Neither XO nor XD activity changed in allopurinol-treated rats at the times of ischaemia. These results indicated that ischaemic brain tissue remained vulnerable to free radical damage for as long as 48 h after ischaemia, and XO was probably not an important source of free radicals in cerebral ischaemia. 相似文献
37.
Cross-Reactions between the Cytotoxic T-Lymphocyte Responses of Human Immunodeficiency Virus-Infected African and European Patients 总被引:13,自引:5,他引:8 下载免费PDF全文
Deniz Durali Jacques Morvan Franck Letourneur Doris Schmitt Nelly Guegan Marc Dalod Sentob Saragosti Didier Sicard Jean-Paul Levy Elisabeth Gomard 《Journal of virology》1998,72(5):3547-3553
The great variability of protein sequences from human immunodeficiency virus (HIV) type 1 (HIV-1) isolates represents a major obstacle to the development of an effective vaccine against this virus. The surface protein (Env), which is the predominant target of neutralizing antibodies, is particularly variable. Here we examine the impact of variability among different HIV-1 subtypes (clades) on cytotoxic T-lymphocyte (CTL) activities, the other major component of the antiviral immune response. CTLs are produced not only against Env but also against other structural proteins, as well as some regulatory proteins. The genetic subtypes of HIV-1 were determined for Env and Gag from several patients infected either in France or in Africa. The cross-reactivities of the CTLs were tested with target cells expressing selected proteins from HIV-1 isolates of clade A or B or from HIV type 2 isolates. All African patients were infected with viruses belonging to clade A for Env and for Gag, except for one patient who was infected with a clade A Env-clade G Gag recombinant virus. All patients infected in France were infected with clade B viruses. The CTL responses obtained from all the African and all the French individuals tested showed frequent cross-reactions with proteins of the heterologous clade. Epitopes conserved between the viruses of clades A and B appeared especially frequent in Gag p24, Gag p18, integrase, and the central region of Nef. Cross-reactivity also existed among Gag epitopes of clades A, B, and G, as shown by the results for the patient infected with the clade A Env-clade G Gag recombinant virus. These results show that CTLs raised against viral antigens from different clades are able to cross-react, emphasizing the possibility of obtaining cross-immunizations for this part of the immune response in vaccinated individuals. 相似文献
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Sanaz Gabery Nellie Georgiou-Karistianis Sofia Hult Lundh Rachel Y. Cheong Andrew Churchyard Phyllis Chua Julie C. Stout Gary F. Egan Deniz Kirik ?sa Petersén 《PloS one》2015,10(2)
Huntington disease (HD) is a fatal neurodegenerative disorder caused by an expanded CAG repeat in the huntingtin gene. Non-motor symptoms and signs such as psychiatric disturbances, sleep problems and metabolic dysfunction are part of the disease manifestation. These aspects may relate to changes in the hypothalamus, an area of the brain involved in the regulation of emotion, sleep and metabolism. Neuropathological and imaging studies using both voxel-based morphometry (VBM) of magnetic resonance imaging (MRI) as well as positron emission tomography (PET) have demonstrated pathological changes in the hypothalamic region during early stages in symptomatic HD. In this investigation, we aimed to establish a robust method for measurements of the hypothalamic volume in MRI in order to determine whether the hypothalamic dysfunction in HD is associated with the volume of this region. Using T1-weighted imaging, we describe a reproducible delineation procedure to estimate the hypothalamic volume which was based on the same landmarks used in histologically processed postmortem hypothalamic tissue. Participants included 36 prodromal HD (pre-HD), 33 symptomatic HD (symp-HD) and 33 control participants who underwent MRI scanning at baseline and 18 months follow-up as part of the IMAGE-HD study. We found no evidence of cross-sectional or longitudinal changes between groups in hypothalamic volume. Our results suggest that hypothalamic pathology in HD is not associated with volume changes. 相似文献
40.
Ophélie Vacca Brahim El Mathari Marie Darche José-Alain Sahel Alvaro Rendon Deniz Dalkara 《Journal of visualized experiments : JoVE》2015,(98)
Müller cells are the principal glial cells of the retina. Their end-feet form the limits of the retina at the outer and inner limiting membranes (ILM), and in conjunction with astrocytes, pericytes and endothelial cells they establish the blood-retinal barrier (BRB). BRB limits material transport between the bloodstream and the retina while the ILM acts as a basement membrane that defines histologically the border between the retina and the vitreous cavity. Labeling Müller cells is particularly relevant to study the physical state of the retinal barriers, as these cells are an integral part of the BRB and ILM. Both BRB and ILM are frequently altered in retinal disease and are responsible for disease symptoms.There are several well-established methods to study the integrity of the BRB, such as the Evans blue assay or fluorescein angiography. However these methods do not provide information on the extent of BRB permeability to larger molecules, in nanometer range. Furthermore, they do not provide information on the state of other retinal barriers such as the ILM. To study BRB permeability alongside retinal ILM, we used an AAV based method that provides information on permeability of BRB to larger molecules while indicating the state of the ILM and extracellular matrix proteins in disease states. Two AAV variants are useful for such study: AAV5 and ShH10. AAV5 has a natural tropism for photoreceptors but it cannot get across to the outer retina when administered into the vitreous when the ILM is intact (i.e., in wild-type retinas). ShH10 has a strong tropism towards glial cells and will selectively label Müller glia in both healthy and diseased retinas. ShH10 provides more efficient gene delivery in retinas where ILM is compromised. These viral tools coupled with immunohistochemistry and blood-DNA analysis shed light onto the state of retinal barriers in disease. 相似文献