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991.
Visualization of the amygdalo–hippocampal border and its structural variability by 7T and 3T magnetic resonance imaging 下载免费PDF全文
Johanna Derix Shan Yang Falk Lüsebrink Lukas Dominique Josef Fiederer Andreas Schulze‐Bonhage Ad Aertsen Tonio Ball 《Human brain mapping》2014,35(9):4316-4329
The amygdala and the hippocampus are two adjacent structures in the medial temporal lobe that have been broadly investigated in functional and structural neuroimaging due to their central importance in sensory perception, emotion, and memory. Exact demarcation of the amygdalo‐hippocampal border (AHB) is, however, difficult in conventional structural imaging. Recent evidence suggests that, due to this difficulty, functional activation sites with high probability of being located in the hippocampus may erroneously be assigned to the amygdala, and vice versa. In the present study, we investigated the potential of ultra‐high‐field magnetic resonance imaging (MRI) in single sessions for detecting the AHB in humans. We show for the first time the detailed structure of the AHB as it can be visualized in T1‐weighted 7T in vivo images at 0.5‐mm3 isotropic resolution. Compared to data acquired at 3T, 7T images revealed considerably more structural detail in the AHB region. Thus, we observed a striking inter‐hemispheric and interindividual variability of the exact anatomical configuration of the AHB that points to the necessity of individual imaging of the AHB as a prerequisite for accurate anatomical assignment in this region. The findings of the present study demonstrate the usefulness of ultra‐high‐field structural MRI to resolve anatomical ambiguities of the human AHB. Highly accurate morphometric and functional investigations in this region at 7T may allow addressing such hitherto unexplored issues as whether the structural configuration of the AHB is related to functional differences in amygdalo‐hippocampal interaction. Hum Brain Mapp 35:4316–4329, 2014. © 2014 Wiley Periodicals, Inc . 相似文献
992.
Encoding of nested levels of acoustic regularity in hierarchically organized areas of the human auditory cortex 下载免费PDF全文
Marc Recasens Sabine Grimm Andreas Wollbrink Christo Pantev Carles Escera 《Human brain mapping》2014,35(11):5701-5716
Our auditory system is able to encode acoustic regularity of growing levels of complexity to model and predict incoming events. Recent evidence suggests that early indices of deviance detection in the time range of the middle‐latency responses (MLR) precede the mismatch negativity (MMN), a well‐established error response associated with deviance detection. While studies suggest that only the MMN, but not early deviance‐related MLR, underlie complex regularity levels, it is not clear whether these two mechanisms interplay during scene analysis by encoding nested levels of acoustic regularity, and whether neuronal sources underlying local and global deviations are hierarchically organized. We registered magnetoencephalographic evoked fields to rapidly presented four‐tone local sequences containing a frequency change. Temporally integrated local events, in turn, defined global regularities, which were infrequently violated by a tone repetition. A global magnetic mismatch negativity (MMNm) was obtained at 140–220 ms when breaking the global regularity, but no deviance‐related effects were shown in early latencies. Conversely, Nbm (45–55 ms) and Pbm (60–75 ms) deflections of the MLR, and an earlier MMNm response at 120–160 ms, responded to local violations. Distinct neuronal generators in the auditory cortex underlay the processing of local and global regularity violations, suggesting that nested levels of complexity of auditory object representations are represented in separated cortical areas. Our results suggest that the different processing stages and anatomical areas involved in the encoding of auditory representations, and the subsequent detection of its violations, are hierarchically organized in the human auditory cortex. Hum Brain Mapp 35:5701–5716, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
993.
Claire Bridel Judit Horvath Mary Kurian André Truffert Andreas Steck Patrice H. Lalive 《Journal of the peripheral nervous system : JPNS》2014,19(2):180-182
Multifocal motor neuropathy (MMN) and anti‐myelin‐associated glycoprotein (anti‐MAG)‐associated neuropathy are clinically and electrophysiologically distinct entities. We describe a patient with characteristic features of both neuropathies, raising the possibility of an overlap syndrome. A 49‐year‐old patient reported a history of slowly progressive predominantly distal tetraparesis, with mild sensory deficits. Nerve conduction studies demonstrated persistent motor conduction blocks outside compression sites, typical of MMN. Laboratory findings revealed persistently high titers of anti‐MAG immunoglobulin Mλ (IgMλ) paraprotein in the context of a monoclonal gammapathy of unknown significance. Skin biopsy of distal lower limb revealed IgM positive terminal nerve perineurium deposits. This case suggests that the distinction between subtypes of chronic inflammatory neuropathies may not be as clear as initially thought, and that the pattern of pathogenicity of anti‐MAG antibodies may vary. 相似文献
994.
Herwig Kloimstein MD MSc Rudolf Likar MD Prof Michael Kern MD Josef Neuhold MD Miroslav Cada MD Nadja Loinig MD Wilfried Ilias MD Prof Brigitta Freundl MD Heinrich Binder MD Andreas Wolf MD Christian Dorn MD Prof Eva Maria Mozes‐Balla MD Rolf Stein MD Ivo Lappe MD Sabine Sator‐Katzenschlager MD Prof 《Neuromodulation》2014,17(2):180-187
995.
Dirk M. Hermann Andreas Kribben Heike Bruck 《Journal of neural transmission (Vienna, Austria : 1996)》2014,121(6):627-632
Cognitive deficits have a high prevalence in elderly patients with chronic kidney disease (CKD). The clinical picture consists of cognitive slowing, executive, memory and language deficits, and is attributed to cerebral white matter disease and clinically often silent brain infarcts. In the meantime, robust evidence exists that low estimated glomerular filtration rate, a measure of CKD severity, predisposes to cognitive deficits, cerebral white matter lesions, and ischemic brain infarcts in addition to demographic factors, vascular risk factors and diseases which also contribute to CKD-related cognitive deficits. In terminal CKD, cerebral blood flow is compromized during hemodialysis sessions, resulting in oxygen desaturation, cognitive deterioration and—in the longer run—brain atrophy. Kidney transplantation improves cognitive deficits in terminal CKD. At all stages, vascular risk factors and associated diseases should stringently be treated according to therapeutic guidelines. 相似文献
996.
Marietta Zille Denise Harhausen Marijke De Saint-Hubert Roger Michel Chris P Reutelingsperger Ulrich Dirnagl Andreas Wunder 《Journal of cerebral blood flow and metabolism》2014,34(9):1568-1570
Cell death is one of the pathophysiological hallmarks after stroke. Markers to image cell death pathways in vivo are highly desirable. We previously showed that fluorescently labeled Annexin A5 (AnxA5), which binds specifically to phosphatidylserine (PS) on dead/dying cells, can be used in experimental stroke for monitoring cell death with optical imaging. Here we investigated whether dual-labeled AnxA5 (technetium and fluorescence label) can be used for single-photon emission computed tomography (SPECT) of cell death in the same model. C57Bl6/N mice were subjected to 60-minute middle cerebral artery occlusion (MCAO) and underwent SPECT imaging at 24, 48, and 72 hours afterwards. They were injected intravenously with either PS-binding AnxA5 or the nonfunctional AnxA5 (negative control), labeled with 99mTc and Alexa Fluor 568, respectively. After SPECT imaging, brain sections were cut for autoradiography and fluorescence microscopy. Ethanol-induced cell death in the femur muscle was used as positive control. We detected dual-labeled AnxA5 in the model of ethanol-induced cell death in the femur muscle, but not after MCAO at any time point, either with SPECT or with ex vivo autoradiography or fluorescence microscopy. Dual-labeled AnxA5 appears to be unsuited for visualizing death of brain cells in this MCAO model. 相似文献
997.
Five Freely Circulating miRNAs and Bone Tissue miRNAs Are Associated With Osteoporotic Fractures 下载免费PDF全文
Claudine Seeliger Katrin Karpinski Alexander T Haug Helen Vester Andreas Schmitt Jan S Bauer Martijn van Griensven 《Journal of bone and mineral research》2014,29(8):1718-1728
Osteoporosis as a systemic skeletal disorder is characterized by increased bone fragility and the risk of fractures. According to the World Health Organization, osteoporosis is one of the 10 most common diseases and affects approximately 75 million people in Europe, the United States, and Japan. In this context, the identification of specific microRNA (miRNA) signatures is an important step for new diagnostic and therapeutic approaches. The focus of interest on miRNAs as biomarkers came with new publications identifying free circulating extracellular miRNAs associated with various types of cancer. This study aimed to identify specific miRNAs in patients with osteoporotic fractures compared with nonosteoporotic fractures. For the array analysis, miRNAs were isolated from the serum of 20 patients with hip fractures, transcribed, and the samples were pooled into 10 osteoporotic and 10 nonosteoporotic specimens. With each pool of samples, human serum and plasma miRNA PCR arrays were performed, which are able to identify 83 different miRNAs. Subsequently, a separate validation analysis of each miRNA found to be regulated in the array followed with miRNA samples isolated from the serum of 30 osteoporotic and 30 nonosteoporotic patients and miRNA samples isolated from the bone tissue of 20 osteoporotic and 20 nonosteoporotic patients. With the validation analysis of the regulated miRNAs, we identified 9 miRNAs, namely miR‐21, miR‐23a, miR‐24, miR‐93, miR‐100, miR‐122a, miR‐124a, miR‐125b, and miR‐148a, that were significantly upregulated in the serum of patients with osteoporosis. In the bone tissue of osteoporotic patients, we identified that miR‐21, miR‐23a, miR‐24, miR‐25, miR‐100, and miR‐125b displayed a significantly higher expression. A total of 5 miRNAs display an upregulation both in serum and bone tissue. This study reveals an important role for several miRNAs in osteoporotic patients and suggested that they may be used as biomarkers for diagnostic purposes and may be a target for treating bone loss and optimizing fracture healing in osteoporotic patients. © 2014 American Society for Bone and Mineral Research. 相似文献
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Thomas Krebs Michael Boettcher Hansjörg Schäfer Georg Eschenburg Katharina Wenke Birgit Appl Beate Roth Thomas Andreas Carla Schmitz Rebecca Fahje Birthe Jacobsen Bastian Tiemann Konrad Reinshagen Kurt Hecher Robert Bergholz 《Surgical endoscopy》2014,28(8):2437-2442