全文获取类型
收费全文 | 2047篇 |
免费 | 101篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 55篇 |
妇产科学 | 28篇 |
基础医学 | 187篇 |
口腔科学 | 35篇 |
临床医学 | 150篇 |
内科学 | 468篇 |
皮肤病学 | 14篇 |
神经病学 | 125篇 |
特种医学 | 93篇 |
外科学 | 408篇 |
综合类 | 19篇 |
一般理论 | 2篇 |
预防医学 | 183篇 |
眼科学 | 14篇 |
药学 | 100篇 |
中国医学 | 4篇 |
肿瘤学 | 233篇 |
出版年
2024年 | 2篇 |
2023年 | 20篇 |
2022年 | 26篇 |
2021年 | 65篇 |
2020年 | 56篇 |
2019年 | 58篇 |
2018年 | 93篇 |
2017年 | 47篇 |
2016年 | 51篇 |
2015年 | 57篇 |
2014年 | 87篇 |
2013年 | 105篇 |
2012年 | 182篇 |
2011年 | 188篇 |
2010年 | 99篇 |
2009年 | 91篇 |
2008年 | 138篇 |
2007年 | 148篇 |
2006年 | 119篇 |
2005年 | 88篇 |
2004年 | 71篇 |
2003年 | 66篇 |
2002年 | 63篇 |
2001年 | 16篇 |
2000年 | 16篇 |
1999年 | 15篇 |
1998年 | 16篇 |
1997年 | 6篇 |
1996年 | 9篇 |
1995年 | 10篇 |
1994年 | 7篇 |
1993年 | 10篇 |
1992年 | 13篇 |
1991年 | 9篇 |
1990年 | 16篇 |
1989年 | 10篇 |
1988年 | 10篇 |
1987年 | 20篇 |
1986年 | 10篇 |
1985年 | 9篇 |
1984年 | 11篇 |
1980年 | 2篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1969年 | 3篇 |
1967年 | 3篇 |
1936年 | 1篇 |
排序方式: 共有2161条查询结果,搜索用时 15 毫秒
91.
Bas C. Stunnenberg MD Samantha LoRusso MD W. David Arnold MD Richard J. Barohn MD Stephen C. Cannon MD PhD Bertrand Fontaine MD PhD Robert C. Griggs MD Michael G. Hanna FRCP FMedSci Emma Matthews MRCP PhD Giovanni Meola MD PhD Valeria A. Sansone MD PhD Jaya R. Trivedi MD Baziel G.M. van Engelen MD PhD Savine Vicart MD Jeffrey M. Statland MD 《Muscle & nerve》2020,62(4):430-444
The nondystrophic myotonias are rare muscle hyperexcitability disorders caused by gain-of-function mutations in the SCN4A gene or loss-of-function mutations in the CLCN1 gene. Clinically, they are characterized by myotonia, defined as delayed muscle relaxation after voluntary contraction, which leads to symptoms of muscle stiffness, pain, fatigue, and weakness. Diagnosis is based on history and examination findings, the presence of electrical myotonia on electromyography, and genetic confirmation. In the absence of genetic confirmation, the diagnosis is supported by detailed electrophysiological testing, exclusion of other related disorders, and analysis of a variant of uncertain significance if present. Symptomatic treatment with a sodium channel blocker, such as mexiletine, is usually the first step in management, as well as educating patients about potential anesthetic complications. 相似文献
92.
Sabine Gretenkord Bas M. J. Olthof Myrto Stylianou Adrian Rees Sarah E. Gartside Fiona E. N. LeBeau 《The European journal of neuroscience》2020,52(2):2915-2930
The role of dopamine in regulating sleep‐state transitions during, both natural sleep and under anaesthesia, is still unclear. Recording in vivo in the rat mPFC under urethane anaesthesia, we observed predominantly slow wave activity (SWA) of <1 Hz in the local field potential interrupted by occasional spontaneous transitions to a low‐amplitude‐fast (LAF) pattern of activity. During periods of SWA, transitions to LAF activity could be rapidly and consistently evoked by electrical stimulation of the ventral tegmental area (VTA). Spontaneous LAF activity, and that evoked by stimulation of the VTA, consisted of fast oscillations similar to those seen in the rapid eye movement (REM)‐like sleep state. Spontaneous and VTA stimulation‐evoked LAF activity occurred simultaneously along the dorsoventral extent of all mPFC subregions. Evoked LAF activity depended on VTA stimulation current and could be elicited using either regular (25–50 Hz) or burst stimulation patterns and was reproducible upon repeated stimulation. Simultaneous extracellular single‐unit recordings showed that during SWA, presumed pyramidal cells fired phasically and almost exclusively on the Up state, while during both spontaneous and VTA‐evoked LAF activity, they fired tonically. The transition to LAF activity evoked by VTA stimulation depended on dopamine D1‐like receptor activation as it was almost completely blocked by systemic administration of the D1‐like receptor antagonist SCH23390. Overall, our data demonstrate that activation of dopamine D1‐like receptors in the mPFC is important for regulating sleep‐like state transitions. 相似文献
93.
Sanne C. F. A. Huijberts Robin M. J. M. van Geel Emilie M. J. van Brummelen Frans L. Opdam Serena Marchetti Neeltje Steeghs Saskia Pulleman Bas Thijssen Hilde Rosing Kim Monkhorst Alwin D. R. Huitema Jos H. Beijnen Ren Bernards Jan H. M. Schellens 《Cancer chemotherapy and pharmacology》2020,85(5):917-930
KRAS oncogene mutations cause sustained signaling through the MAPK pathway. Concurrent inhibition of MEK, EGFR, and HER2 resulted in complete inhibition of tumor growth in KRAS-mutant (KRASm) and PIK3CA wild-type tumors, in vitro and in vivo. In this phase I study, patients with advanced KRASm and PIK3CA wild-type colorectal cancer (CRC), non-small cell lung cancer (NSCLC), and pancreatic cancer, were treated with combined lapatinib and trametinib to assess the recommended phase 2 regimen (RP2R). Patients received escalating doses of continuous or intermittent once daily (QD) orally administered lapatinib and trametinib, starting at 750 mg and 1 mg continuously, respectively. Thirty-four patients (16 CRC, 15 NSCLC, three pancreatic cancers) were enrolled across six dose levels and eight patients experienced dose-limiting toxicities, including grade 3 diarrhea (n = 2), rash (n = 2), nausea (n = 1), multiple grade 2 toxicities (n = 1), and aspartate aminotransferase elevation (n = 1), resulting in the inability to receive 75% of planned doses (n = 2) or treatment delay (n = 2). The RP2R with continuous dosing was 750 mg lapatinib QD plus 1 mg trametinib QD and with intermittent dosing 750 mg lapatinib QD and trametinib 1.5 mg QD 5 days on/2 days off. Regression of target lesions was seen in 6 of the 24 patients evaluable for response, with one confirmed partial response in NSCLC. Pharmacokinetic results were as expected. Lapatinib and trametinib could be combined in an intermittent dosing schedule in patients with manageable toxicity. Preliminary signs of anti-tumor activity in NSCLC have been observed and pharmacodynamic target engagement was demonstrated. 相似文献
94.
Overbeek Kasper A. Cahen Djuna L. Kamps Anne Konings Ingrid C. A. W. Harinck Femme Kuenen Marianne A. Koerkamp Bas Groot Besselink Marc G. van Eijck Casper H. Wagner Anja Ausems Margreet G. E. van der Vlugt Manon Fockens Paul Vleggaar Frank P. Poley Jan-Werner van Hooft Jeanin E. Bleiker Eveline M. A. Bruno Marco J. 《Familial cancer》2020,19(3):247-258
Familial Cancer - In high-risk individuals participating in a pancreatic cancer surveillance program, worrisome features warrant for intensified surveillance or, occasionally, surgery. Our... 相似文献
95.
Therese Muzeniek Thejanee Perera Sahan Siriwardana Dilara Bas Fatimanur Kaplan Mizgin
ruc Beate Becker-Ziaja Inoka Perera Jagathpriya Weerasena Shiroma Handunnetti Franziska Schwarz Gayani Premawansa Sunil Premawansa Wipula Yapa Andreas Nitsche Claudia Kohl 《Viruses》2022,14(2)
Coronaviruses (CoV) are divided into the genera α-CoVs, β-CoVs, γ-CoVs and δ-CoVs. Of these, α-CoVs and β-CoVs are solely capable of causing infections in humans, resulting in mild to severe respiratory symptoms. Bats have been identified as natural reservoir hosts for CoVs belonging to these two genera. Consequently, research on bat populations, CoV prevalence in bats and genetic characterization of bat CoVs is of special interest to investigate the potential transmission risks. We present the genome sequence of a novel α-CoV strain detected in rectal swab samples of Miniopterus fuliginosus bats from a colony in the Wavul Galge cave (Koslanda, Sri Lanka). The novel strain is highly similar to Miniopterus bat coronavirus 1, an α-CoV located in the subgenus of Minunacoviruses. Phylogenetic reconstruction revealed a high identity of the novel strain to other α-CoVs derived from Miniopterus bats, while human-pathogenic α-CoV strains like HCoV-229E and HCoV-NL63 were more distantly related. Comparison with selected bat-related and human-pathogenic strains of the β-CoV genus showed low identities of ~40%. Analyses of the different genes on nucleotide and amino acid level revealed that the non-structural ORF1a/1b are more conserved among α-CoVs and β-CoVs, while there are higher variations in the structural proteins known to be important for host specificity. The novel strain was named batCoV/MinFul/2018/SriLanka and had a prevalence of 50% (66/130) in rectal swab samples and 58% (61/104) in feces samples that were collected from Miniopterus bats in Wavul Galge cave. Based on the differences between strain batCoV/MinFul/2018/SriLanka and human-pathogenic α-CoVs and β-CoVs, we conclude that there is a rather low transmission risk to humans. Further studies in the Wavul Galge cave and at other locations in Sri Lanka will give more detailed information about the prevalence of this virus. 相似文献
96.
Feasibility of synchrotron radiation computed tomography on rats bearing glioma after iodine or gadolinium injection 总被引:2,自引:0,他引:2
Le Duc G Corde S Elleaume H Estève F Charvet AM Brochard T Fiedler S Collomb A Le Bas JF 《European radiology》2000,10(9):1487-1492
The purpose of this work was to demonstrate the feasibility of a new imaging technique called synchrotron radiation computed
tomography (SRCT). This technique leads to a direct assessment of the in vivo concentration of an iodine- or gadolinium-labeled
compound. Rats bearing C6 glioma were imaged by MRI prior to the SRCT experiment. The SRCT experiments were performed after
a 1.3 g I/kg (n = 5) or a 0.4 g Gd/kg (n = 5) injection. Finally, brains were sampled for histology. The SRCT images exhibited contrast enhancement at the tumor location.
Ten minutes after injection, iodine and gadolinium tissular concentrations were equal to 0.80 ( ± 0.40) mg/cm3 and 0.50 ( ± 0.10) mg/cm3, respectively in the peripheral area of the tumor (respective background value: 0.20 ± 0.02 to 0.10 ± 0.01). Correlation
to MRI and histology revealed that the contrast uptake occurred in the most vascularized area of the tumor. The present study
summarizes the feasibility of in vivo SRCT to obtain quantitative information about iodine and gadolinium-labeled compounds.
Beyond brain tumor pathology, the SRCT appears as a complementary approach to MRI and CT, for studying iodine- and gadolinium-labeled
compounds by the direct achievement of the tissular concentration value in the tissue.
Received: 8 September 1999; Revised: 3 May 2000; Accepted: 4 May 2000 相似文献
97.
98.
99.
Developments in image acquisition technology make high volumes of neuron images available to neuroscientists for analysis. However, manual processing of these images is not practical and is infeasible for larger and larger scale studies. Reliable interpretation and analysis of high volume data requires accurate quantitative measures. This requires analysis algorithms to use mathematical models that inherit the underlying geometry of biological structures in order to extract topological information. In this paper, we first introduce principal curves as a model for the underlying skeleton of axons and branches, then describe a recursive principal curve tracing?(RPCT) method to extract this topology information from 3D microscopy imagery. RPCT first finds samples on the one dimensional principal set of the intensity function in space. Then, given an initial direction and location, the algorithm iteratively traces the principal curve in space using our principal curve tracing?(PCT) method. Recursive implementation of PCT provides a compact solution for extracting complex tubular structures that exhibit bifurcations. 相似文献