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101.
Heinz C. Schröder August Bernd Rudolf K. Zahn Werner E.G. Müller 《Mechanisms of ageing and development》1983,22(1):35-50
Microtubules have been isolated from immature (3-4 weeks' old) and old (11-13 years' old) bovine brains. Quantitative studies revealed that the concentration of extractable microtubule protein per gram of wet brain decreased from 0.47 mg (immature animals) to 0.34 mg (old animals). The major components of microtubule protein (tubulin and high-molecular-weight microtubule-associated proteins) do not undergo an age-correlated change. Determination of the endogenous protein kinase activity revealed that the activity associated with "immature" calf brain microtubules was six times higher than the activity present in "old" preparations. In contrast, the stimulatory effect of cyclic AMP on protein phosphorylation in microtubules from old bovine brains exceeds nine-fold the value obtained from immature animals. After addition of casein (exogenous acceptor), the basal activities increased in both preparations without altering the age-correlated difference in the specific activity. By comparing the radioactivity pattern of sodium dodecyl sulfate polyacrylamide gels after autophosphorylation of microtubule protein with [gamma-32P]ATP, 1.5 moles of phosphate per mole of high-molecular-weight microtubule-associated protein were estimated to be incorporated in preparations from immature animals and 0.9 mole of phosphate per mole of associated protein in the experiments with "old" microtubule protein. Adenosine triphosphatase activity, associated with the high-molecular-weight microtubule-associated protein 1, was determined to be 15% reduced in preparations from old animals, compared to the activity in "young" preparations. In contrast, the guanosine triphosphatase activity increased five-fold during ageing; the higher activity of this enzyme was observed both during the initial and the steady-state phases of microtubule formation. 相似文献
102.
Michael Steinhausen Frederick D. Dallenbach Rudolf Jäckh Niranjan Parekh Bernd Zimmerhackl Rainer Zimmermann 《Virchows Archiv : an international journal of pathology》1979,384(1):65-84
Summary After occlusion of the renal veins rats die quickly in progressive shock (within 4.5 h), but after ligating the renal hilum of both Kidneys they survive 27 h. To learn why renal vein occlusion is so rapidly lethal, and what substances are given off and by what method from the hemorrhagically infarcted kidneys, we studied eight groups of rats, each containing at least seven animals. The groups differed in the combination of hilar structures (renal veins, ureters, lymphatics) ligated. We compared: survival times, changes in blood pressure, blood volume, levels of plasma kinins, adenosine, and lactate, changes of blood pH, responses to Indomethacin, Trasylol®, and plasma expanders, tubular and capillary flow rates, histopathological changes in organs and cerebral blood flow and changes in the blood coagulation system. Our results suggest that the venous stasis, anoxia, and hemorrhagic necrosis caused by bilateral venous occlusion release into renal lymphatics toxic substances which reach the systemic circulation and induce irreversible shock. We have excluded prostaglandins and adenosine as the toxic substances inducing shock but could not rule out an action of the kallikrein-kinin-system. We postulate that the striking degenerative changes occurring in the arterioles of the brain after bilateral venous occlusion may mean these vessels are especially susceptible to high levels of lactic acid and that this may explain why these animals die so quickly. Our conclusions should help not only in understanding why high levels of lactate in shock portend a poor prognosis but also help in formulating appropriate therapy for circulatory failure of renal origin and for protracted hypotension after extensive tissue injury.The studies were supported by the German Research Foundation within the SFB 90 Cardiovasculäres SystemPresented in part: Jäckh and Steinhausen, 1976; Dallenbach et al., 1978; Zimmerhackl et al., 1979We dedicate this paper to Wilhelm Doerr, Dr. med., Professor of Pathology, University of Heidelberg on the occasion of his 65th birthday (August 25th, 1979) 相似文献
103.
104.
Weren A Bonnekoh B Schraven B Gollnick H Ambach A 《Journal of immunological methods》2004,289(1-2):17-26
CD8(hi+) cytotoxic T lymphocytes (CTL) are major players in immune defense. In addition, they contribute to the maintenance of immune homeostasis. We now describe a hitherto unavailable, but simple assay to determine ex vivo lytic granule-based cytotoxic functions of human CD8(hi+) CTL subgroups in a clinical setting, under target cell free conditions. Ficoll-isolated peripheral blood lymphocytes from 17 healthy volunteers were stimulated either by phorbol 12-myristate 13-acetate (PMA) in combination with ionomycin or by antibody mediated crosslinking of the CD3 molecule on the T cell surface. Using perforin as a marker for lytic granules, the reduction of CTL granules over time intervals up to 120 min was quantified by FACScan flow cytometry. The kinetics of perforin reduction were compared to the kinetics of NA-CBZ-L-lysine-thiobenzyl ester hydrochloride (BLT)-esterase release and of CD63 upregulation. The reduction in the perforin(+) portion of CD8(hi+) CTLs was correlated inversely with BLT-esterase release and CD63 upregulation. At 30 and 120 min after PMA/ionomycin stimulation, 55 +/- 14% and 42 +/- 14%, respectively, of CD8(hi+) CTLs still stained perforin(+) (time point 0 min = 100%). Perforin-granule release induced by CD3-crosslinking occurred as fast within 30 min (55 +/- 17%), but over the 120 min time interval it was not as complete when compared to PMA/ionomycin-stimulated perforin-reduction. Thus, the combination of an established degranulation assay with the power of immuno flow cytometry allows one to investigate the cytotoxic capability of CTL-subtypes and the kinetics of perforin-granule release. In addition, the assay may prove useful in the elucidation of intracellular signaling cascades governing the perforin-granule release process. 相似文献
105.
It is now clear that atherosclerotic disease is a chronic inflammatory disease triggered by a sequence of events initiated at sites with turbulent flow under normal conditions such as in the coronary arteries or at bifurcations or where normal laminar flow is replaced by turbulent flow because of vessel pathologies. Normally, laminar flow is protected by generation of NO by endothelial NO synthase (eNOS), which becomes activated via stretch activated channels. When the flow turns turbulent, such protective NO generation ceases, leading to endothelial cell activation and lipid deposition into the extra-cellular space. There, lipoproteins and specifically phospholipids become oxidized by cells of the monocytic-macrophage lineage. Only when the LDL-cholesterol level is high enough lipid peroxidation products are generated in sufficient amounts to perpetuate the disease by generating a feed forward loop of endothelial cell activation leading to an inflammatory response. That inflammatory response might also be added by bacterial or viral infections such as Chlamydia pneumoniae or viruses. The disease then progresses to a chronic inflammatory state, whereby the immune system seems to contribute significantly and markers of chronic inflammation such as fibrinogen, leukocytes, PAI-1 and CRP are found increased. 相似文献
106.
Norgauer J Ibig Y Gmeiner D Herouy Y Fiebich BL 《International journal of molecular medicine》2003,12(1):83-86
Prostaglandin E2 (PGE2), which is generated by the enzymatic activity of cyclooxygenase-1 and -2 (COX-1/2), plays a central role in the maturation process of dendritic cells (DC). Since regulation of COX-1/2 expression in human DC is only partially understood, we addressed the expression and activity of COX-1/2 in these cells. Here we show that lipopolysaccharide (lps) induces COX-2 mRNA and protein synthesis as well as the release of PGE2 in human interleukin-4 and granulocyte/macrophage colony-stimulating factor-differentiated monocyte-derived DC cultivated in the presence of 1% human plasma. Moreover, we found that lps induces p38 stress-activated protein kinase (p38) in these cells and inhibitors of p38 blocked lps-induced COX-2 expression and activity. Our data indicate that during lps-induced maturation p38 regulates COX-2 expression and PGE2 synthesis in DC. 相似文献
107.
In a pilot project of the Department of Bone Pathology of the University of Hamburg and the Orthopaedic Department of the University of Heidelberg, the cases of 121 patients with suspicion of a primary bone tumour have been discussed at weekly interdisciplinary conferences during the period from July 2001 to May 2002., The consequent differential diagnoses were made prior to the biopsy, the optimal location of the biopsy and the further strategy was determined according to the guidelines of the international bone tumour centres. The latter includes the decision if a conventional biopsy or a intraoperative pathology examination on frozen sections should be performed. In 27 cases an intraoperative pathology examination was performed and then assessed in Hamburg. In 24 cases this diagnosis was identical with the final diagnosis. In three cases no definitive diagnosis could be made from the frozen sections. Additionally the pathohistological diagnoses of the cases of the previous week have been discussed in the video-conferences. Through this a unusually close interdisciplinary cooperation over a large distance has evolved, that is highly appreciated especially by the young and less experienced colleagues at the department of bone pathology and the orthopaedic department in Heidelberg. The awareness of the potential and limitations of a medical subject leads to an improved safety in the diagnostic process for bone tumours. The interdisciplinary discussion of all aspects of the diseases may also optimise the therapy of bone tumours. 相似文献
108.
Peter Anderer Georg Gruber Gerhard Klösch Wolfgang Klimesch Bernd Saletu Josef Zeitlhofer 《Somnologie - Schlafforschung und Schlafmedizin》2002,6(2):54-62
Summary Memory consolidation involves a complex series of molecular, cellular and network-level processes that take place on time scales from millisecond to months. Evidence from a wide range of experimental observations supports the hypothesis that parts of these processes occur during sleep when the brain is not engaged in processing and encoding incoming information. Indeed, sleep seems to be favorable for brain plasticity. Experience-dependent cortical plasticity observed during sleep has been hypothesized to be part of the global process of memory consolidation. Thus, studying task-dependent, regionally specific reactivation of neuronal assemblies during posttraining sleep may make important contributions to elucidating the role of sleep in memory trace processing. A new methodology – low-resolution brain electromagnetic tomography (LORETA) – offers the possibility of localizing electrical activity produced by cortical neuronal generators under normal (undisturbed) sleeping conditions. The high time resolution of brain electrical data can be exploited to produce neuroimages for specific EEG spectral frequency bands (e.g. delta, theta, or spindle bands). This makes it possible to investigate, dependent on the type of memory, when – in which sleep stages (S2 sleep, SWS, REM sleep) – and where – in which cortical brain regions (primary sensory cortex, higher association cortex) – experience-dependent reactivation occurs. 相似文献
109.
110.
Paulette Bernd Michael D. Gershon Eladio A. Nunez Hadassah Tamir 《Anatomical record (Hoboken, N.J. : 2007)》1979,193(2):257-267
A highly specific serotonin binding protein (SBP) has been found in serotonergic neurons in both brain and gut. This protein has an extremely high affinity for serotonin and may be a storage protein. Serotonin is found in many endocrine cells, including parafollicular cells of the sheep thyroid, as well as in neurons. SBP is also present in sheep thyroid. The present study was done to localize the protein in the gland. Thyroid glands were divided into five segments. Concentrations of serotonin and SBP, as well as parafollicular cell volume were measured in each. Serotonin was assayed by enzymatic conversion to melatonin using tritiated S-adenosylmethionine. SBP was assayed by molecular sieve chromatography on sephadex G-50. The relative volume of parafollicular cells was obtained by stereological analysis of electron micrographs. Experiments were also done to demonstrate these cells by histofluorescence and radioautography following incubation with tritiated 5-hydroxytryptophan. Good correlations were found between serotonin and SBP concentrations, and parafollicular cell volume. These peaked in the rostro-central portion of the gland and were minimal at the poles. We conclude that thyroid SBP is probably localized in parafollicular cells. 相似文献