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71.
Hyun Jae Pi Nikolai Otmakhov Farida El Gaamouch David Lemelin Paul De Koninck John Lisman 《Proceedings of the National Academy of Sciences of the United States of America》2010,107(32):14437-14442
CaMKII is an abundant synaptic protein strongly implicated in plasticity. Overexpression of autonomous (T286D) CaMKII in CA1 hippocampal cells enhances synaptic strength if T305/T306 sites are not phosphorylated, but decreases synaptic strength if they are phosphorylated. It has generally been thought that spine size and synaptic strength covary; however, the ability of CaMKII and its various phosphorylation states to control spine size has not been previously examined. Using a unique method that allows the effects of overexpressed protein to be monitored over time, we found that all autonomous forms of CaMKII increase spine size. Thus, for instance, the T286D/T305D/T306D form increases spine size but decreases synaptic strength. Further evidence for such dissociation is provided by experiments with the T286D form that has been made catalytically dead. This form fails to enhance synaptic strength but increases spine size, presumably by a structural process. Thus very different mechanisms govern how CaMKII affects spine structure and synaptic function. 相似文献
72.
Femorodistal occlusion can be treated with bypasses or even with endovascular methods nowadays. The TransAtlantic Inter-Society Consensus (TASC) paper recommends the endovascular option for short occlusions up to 5 cm. The primary patency rates for both options are moderate: 70–80%. Since August 2007, the Viabahn Endoprosthesis with Propaten bioactive surface has been in clinical use. In open surgery, the surface activation by means of Propaten can improve the patency rates of femorodistal bypasses up to 97% during the first year after implantation. We show that implantation of the Viabahn Endoprosthesis is feasible; however, because midterm and long-term results are lacking, the patients should be followed up closely. 相似文献
73.
Nikolai E. Lazarov Sebastian Reindl Florian Fischer Manfred Gratzl 《Respiratory physiology & neurobiology》2009,165(2-3):131-136
Carotid body (CB) chemoreceptors are the main sensors detecting systemic hypoxia. Studies in animals revealed that dopamine and histamine may serve as transmitters between the chemoreceptor cells and the afferent nerve. To gain insight whether histamine and dopamine could play a role in the human CB and thus be important for the understanding of breathing disorders, we have investigated the chemosensory traits in human CBs from nine subjects of different ages obtained at autopsy. Immunohistochemistry revealed expression of histidine decarboxylase, vesicular monoamine transporter 2, histamine receptors 1 and 3 in virtually all chemosensory cells within the glomeruli of different ages. By contrast, catecholaminergic traits (tyrosine hydroxylase and vesicular monoamine transporter 1) were only detected in a subset of CB chemosensory cells at each age group while dopamine D2 receptors were expressed in the great majority of them. Our data suggest that histamine along with catecholamines may serve as transmitters between chemoreceptor cells and the afferent nerve in humans as well. 相似文献
74.
75.
Sanford J. Silverman Allegra A. Petti Nikolai Slavov Lance Parsons Ryan Briehof Stephan Y. Thiberge Daniel Zenklusen Saumil J. Gandhi Daniel R. Larson Robert H. Singer David Botstein 《Proceedings of the National Academy of Sciences of the United States of America》2010,107(15):6946-6951
Oscillations in patterns of expression of a large fraction of yeast genes are associated with the “metabolic cycle,” usually seen only in prestarved, continuous cultures of yeast. We used FISH of mRNA in individual cells to test the hypothesis that these oscillations happen in single cells drawn from unsynchronized cultures growing exponentially in chemostats. Gene-expression data from synchronized cultures were used to predict coincident appearance of mRNAs from pairs of genes in the unsynchronized cells. Quantitative analysis of the FISH results shows that individual unsynchronized cells growing slowly because of glucose limitation or phosphate limitation show the predicted oscillations. We conclude that the yeast metabolic cycle is an intrinsic property of yeast metabolism and does not depend on either synchronization or external limitation of growth by the carbon source. 相似文献
76.
Marc Jennewein Matthew A Lewis Dawen Zhao Edward Tsyganov Nikolai Slavine Jin He Linda Watkins Vikram D Kodibagkar Sean O'Kelly Padmakar Kulkarni Peter P Antich Alex Hermanne Frank R?sch Ralph P Mason Philip E Thorpe 《Clinical cancer research》2008,14(5):1377-1385
PURPOSE: We recently reported that anionic phospholipids, principally phosphatidylserine, become exposed on the external surface of vascular endothelial cells in tumors, probably in response to oxidative stresses present in the tumor microenvironment. In the present study, we tested the hypothesis that a chimeric monoclonal antibody that binds phosphatidylserine could be labeled with radioactive arsenic isotopes and used for molecular imaging of solid tumors in rats. EXPERIMENTAL DESIGN: Bavituximab was labeled with (74)As (beta(+), T(1/2) 17.8 days) or (77)As (beta(-), T(1/2) 1.6 days) using a novel procedure. The radionuclides of arsenic were selected because their long half-lives are consistent with the long biological half lives of antibodies in vivo and because their chemistry permits stable attachment to antibodies. The radiolabeled antibodies were tested for the ability to image subcutaneous Dunning prostate R3227-AT1 tumors in rats. RESULTS: Clear images of the tumors were obtained using planar gamma-scintigraphy and positron emission tomography. Biodistribution studies confirmed the specific localization of bavituximab to the tumors. The tumor-to-liver ratio 72 h after injection was 22 for bavituximab compared with 1.5 for an isotype-matched control chimeric antibody of irrelevant specificity. Immunohistochemical studies showed that the bavituximab was labeling the tumor vascular endothelium. CONCLUSIONS: These results show that radioarsenic-labeled bavituximab has potential as a new tool for imaging the vasculature of solid tumors. 相似文献
77.
Deep brain stimulation to reward circuitry alleviates anhedonia in refractory major depression. 总被引:2,自引:0,他引:2
Thomas E Schlaepfer Michael X Cohen Caroline Frick Markus Kosel Daniela Brodesser Nikolai Axmacher Alexius Young Joe Martina Kreft Doris Lenartz Volker Sturm 《Neuropsychopharmacology》2008,33(2):368-377
Deep brain stimulation (DBS) to different sites allows interfering with dysfunctional network function implicated in major depression. Because a prominent clinical feature of depression is anhedonia--the inability to experience pleasure from previously pleasurable activities--and because there is clear evidence of dysfunctions of the reward system in depression, DBS to the nucleus accumbens might offer a new possibility to target depressive symptomatology in otherwise treatment-resistant depression. Three patients suffering from extremely resistant forms of depression, who did not respond to pharmacotherapy, psychotherapy, and electroconvulsive therapy, were implanted with bilateral DBS electrodes in the nucleus accumbens. Stimulation parameters were modified in a double-blind manner, and clinical ratings were assessed at each modification. Additionally, brain metabolism was assessed 1 week before and 1 week after stimulation onset. Clinical ratings improved in all three patients when the stimulator was on, and worsened in all three patients when the stimulator was turned off. Effects were observable immediately, and no side effects occurred in any of the patients. Using FDG-PET, significant changes in brain metabolism as a function of the stimulation in fronto-striatal networks were observed. No unwanted effects of DBS other than those directly related to the surgical procedure (eg pain at sites of implantation) were observed. Dysfunctions of the reward system--in which the nucleus accumbens is a key structure--are implicated in the neurobiology of major depression and might be responsible for impaired reward processing, as evidenced by the symptom of anhedonia. These preliminary findings suggest that DBS to the nucleus accumbens might be a hypothesis-guided approach for refractory major depression. 相似文献
78.
Nikolai Kuhnert Adam Le‐Gresley Daniel C. Nicolau Ana Lopez‐Periago 《Journal of labelled compounds & radiopharmaceuticals》2007,50(13):1215-1223
The synthesis and self‐association of chiral isotopically labeled trianglamine macrocycles under electrospray mass spectrometer conditions in an ion trap are described. A moderate diastereoselectivity in the self‐association process was observed providing a synthetic model system for the investigation of chiral self‐association in the gas phase. The first non‐covalently bound dimer exclusively bonded through aromatic–aromatic interactions was observed in the gas phase. Evidence for self‐association in solution was observed by diffusion nuclear magnetic resonance spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
79.
J R Owiny T Myers G A Massmann D W Sadowsky S Jenkins P W Nathanielsz 《Obstetrics and gynecology》1992,79(1):81-84
Although cocaine abuse during human pregnancy is associated with an increased incidence of preterm labor, there are few reports on the effects of cocaine on myometrial activity during pregnancy in experimental animals. Cocaine (0.5, 1, or 2 mg/kg) or vehicle was randomly administered intravenously to 15 pregnant ewes between 124-146 days' gestation (term is 147 days). Neither cocaine nor vehicle administration altered total myometrial electromyographic activity from pre-dose levels 1 or 6 hours after administration. Maternal arterial plasma oxytocin did not change during the study. Using a positive control, we confirmed observations of other investigators that administration of 2 mg/kg cocaine significantly increases maternal arterial blood pressure. The results indicate that cocaine does not stimulate myometrial contractility significantly in late pregnancy in sheep. 相似文献
80.
Ethyl glucuronide is a minor metabolite of ethanol, and its presence in urine can be used as a laboratory test to detect recent alcohol intake, even for some time after the ethanol is no longer measurable. A simple analytical procedure was developed based on direct injection of urine diluted with a deuterated internal standard into an electrospray liquid chromatographic-mass spectrometric (LC-MS) system. A novel LC system using a porous graphite column (Hypercarb) enabled an isocratic elution with retention times of 5-6 minutes. The intra- and inter-assay coefficients of variation were 2-12%, and the measuring range was 0.1-1,500 mg/L (0.45-6,750 micromol/L). Ethyl glucuronide was found to be stable in urine for more than 4 days at room temperature, and no artifactual formation was observed on storage of urine samples fortified with 1% ethanol. Ethyl glucuronide was not detected in urine samples collected after abstinence from alcohol. Intake of a very low amount (7 g) of ethanol produced ethyl glucuronide values up to 8.4 mg/L after 4 hours and was still detectable at 6 hours. When the method was applied for routine screening of 252 clinical urine samples (range, 0-1,240 mg/L), it fulfilled the need for a simple and reliable assay to be used in the evaluation of urinary ethyl glucuronide as a routine test of recent alcohol intake. 相似文献