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101.
Andrei
V. Smirnov Pavel A. Kots Maksim A. Panteleyev Irina I. Ivanova 《RSC advances》2018,8(64):36970
Catalytic oxidation of 1,1-dimethylhydrazine (UDMH) with molecular oxygen over Pt/SiO2 was studied by in situ FTIR spectroscopy coupled with online MS monitoring of the gas phase. An unusual two-step oxidation process was detected in experiments with the pulse UDMH feeding: initial UDMH oxidation over a fresh platinum surface quickly terminates due to the blockage of active sites; a time-separated second oxidation step corresponds to combustion of the surface residue. This residue consists of C N nitrile groups formed via decomposition of the products of non-oxidative UDMH conversion, such as dimethylamine. The two-step oxidation picture is observed over a broad range of reaction temperatures and oxygen to UDMH ratios.Unusual two-step oxidation process of 1,1-dimethylhydrazine on Pt/SiO2 catalyst. 相似文献
102.
Agnesa Panferova Marina Gaskova Eugenyi Nikitin Pavel Baryshev Natalia Timofeeva Anna Kazakova Viktor Matveev Ekaterina Mikhailova Alexander Popov Irina Kalinina Lili Hachatrian Aleksey Maschan Michael Maschan Galina Novichkova Yulia Olshanskaya 《International journal of laboratory hematology》2021,43(4):713-723
103.
Jay L. Patel Mehrdad Abedi Christopher R. Cogle Harry P. Erba Kathryn Foucar Guillermo Garcia-Manero David L. Grinblatt Rami S. Komrokji Sandra E. Kurtin Jaroslaw P. Maciejewski Daniel A. Pollyea Dennis A. Revicki Gail J. Roboz Michael R. Savona Bart L. Scott Mikkael A. Sekeres David P. Steensma Michael A. Thompson Elizabeth Dawn Flick Pavel Kiselev Chrystal U. Louis Melissa Nifenecker Arlene S. Swern Tracy I. George 《International journal of laboratory hematology》2021,43(3):426-432
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106.
Kitov PI Mulvey GL Griener TP Lipinski T Solomon D Paszkiewicz E Jacobson JM Sadowska JM Suzuki M Yamamura K Armstrong GD Bundle DR 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(44):16837-16842
We demonstrate that interactions between multimeric receptors and multivalent ligands are dramatically enhanced by recruiting a complementary templating receptor such as an endogenous multimeric protein but only when individual ligands are attached to a polymer as preorganized, covalent, heterobifunctional pairs. This effect cannot be replicated by a multivalent ligand if the same recognition elements are independently arrayed on the scaffold. Application of this principle offers an approach to create high-avidity inhibitors for multimeric receptors. Judicious selection of the ligand that engages the templating protein allows appropriate effector function to be incorporated in the polymeric construct, thereby providing an opportunity for therapeutic applications. The power of this approach is exemplified by the design of exceptionally potent Escherichia coli Shiga toxin antagonists that protect transgenic mice that constitutively express a human pentraxin, serum amyloid P component. 相似文献
107.
Pavel G. Tarazov M.D. Kyrill V. Prozorovskij M.D. 《The American journal of gastroenterology》1991,86(6):775-778
A 54-yr-old male with portal hypertension received ineffective medical therapy for the diagnosis of portal hepatic cirrhosis. Duplex ultrasound (US) revealed pulsatile arterial flow in the right main portal vein. The correct diagnosis of intrahepatic arterioportal fistula was established and confirmed by angiography. Right hepatic artery embolization with three coils was performed. The patient is alive for 16 months after the embolization, and his complaints have disappeared. There has been full resorption of ascites and absence of varices. Nine previously reported similar cases are reviewed. 相似文献
108.
Blockade of angiotensin type 1 (AT1) receptors induces smooth muscle cell (SMC) death and regression of aortic hypertrophy in spontaneously hypertensive rats (SHR). We postulated that SMC death and vascular remodeling in this model may be attenuated by z-Val-Ala-Asp(OMe)-CH2F (z-VAD-fmk), a tripeptide inhibitor of caspase enzymes mediating apoptosis. To determine the time course of SMC death and aortic remodeling, SHR were treated with losartan (30 mg/kg per day) for up to 9.5 days. Transient SMC apoptosis occurred in the aortic media with a peak around day 5 of treatment, with increases in the Bax to Bcl-2 protein ratio (>3-fold), in active caspase-3 (5.6-fold), in TUNEL-positive nuclei (19-fold), preceding by 24 hours the peak activation of capase-9 (3.8-fold), and significant reductions in SMC number (46%) and aortic cross-sectional area (8.5%) at 5.5 days. The decrease in total aortic DNA reached significance at 6.5 days (29%). Blood pressure reduction with losartan was progressive and reached significance at day 7 of treatment. Next, we examined the causal link between vascular apoptosis and remodeling. SHR received placebo or losartan (30 mg/kg per day) for 6 days. During the last 24 hours, a subgroup of losartan-treated rats received 3 IV injections of z-VAD-fmk (cumulative dose: 4.4 mg x kg(-1)). All other rats received the vehicle, DMSO. The 24-hour cotreatment with z-VAD-fmk effectively prevented losartan-induced caspase-3 activation and internucleosomal DNA fragmentation, as well as SMC depletion and the reductions in aortic mass and DNA content. Together, these data suggest that caspase-dependent SMC death mediates the early phase of vascular remodeling in response to AT1 receptor blockade in this model of hypertension. 相似文献
109.
Intraspecific phylogenetic analysis of Siberian woolly mammoths using complete mitochondrial genomes
Gilbert MT Drautz DI Lesk AM Ho SY Qi J Ratan A Hsu CH Sher A Dalén L Götherström A Tomsho LP Rendulic S Packard M Campos PF Kuznetsova TV Shidlovskiy F Tikhonov A Willerslev E Iacumin P Buigues B Ericson PG Germonpré M Kosintsev P Nikolaev V Nowak-Kemp M Knight JR Irzyk GP Perbost CS Fredrikson KM Harkins TT Sheridan S Miller W Schuster SC 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(24):8327-8332
We report five new complete mitochondrial DNA (mtDNA) genomes of Siberian woolly mammoth (Mammuthus primigenius), sequenced with up to 73-fold coverage from DNA extracted from hair shaft material. Three of the sequences present the first complete mtDNA genomes of mammoth clade II. Analysis of these and 13 recently published mtDNA genomes demonstrates the existence of two apparently sympatric mtDNA clades that exhibit high interclade divergence. The analytical power afforded by the analysis of the complete mtDNA genomes reveals a surprisingly ancient coalescence age of the two clades, approximately 1-2 million years, depending on the calibration technique. Furthermore, statistical analysis of the temporal distribution of the (14)C ages of these and previously identified members of the two mammoth clades suggests that clade II went extinct before clade I. Modeling of protein structures failed to indicate any important functional difference between genomes belonging to the two clades, suggesting that the loss of clade II more likely is due to genetic drift than a selective sweep. 相似文献
110.
Dissecting virulence: systematic and functional analyses of a pathogenicity island 总被引:32,自引:0,他引:32 下载免费PDF全文
Deng W Puente JL Gruenheid S Li Y Vallance BA Vázquez A Barba J Ibarra JA O'Donnell P Metalnikov P Ashman K Lee S Goode D Pawson T Finlay BB 《Proceedings of the National Academy of Sciences of the United States of America》2004,101(10):3597-3602
Bacterial pathogenicity islands (PAI) often encode both effector molecules responsible for disease and secretion systems that deliver these effectors to host cells. Human enterohemorrhagic Escherichia coli (EHEC), enteropathogenic E. coli, and the mouse pathogen Citrobacter rodentium (CR) possess the locus of enterocyte effacement (LEE) PAI. We systematically mutagenized all 41 CR LEE genes and functionally characterized these mutants in vitro and in a murine infection model. We identified 33 virulence factors, including two virulence regulators and a hierarchical switch for type III secretion. In addition, 7 potential type III effectors encoded outside the LEE were identified by using a proteomics approach. These non-LEE effectors are encoded by three uncharacterized PAIs in EHEC O157, suggesting that these PAIs act cooperatively with the LEE in pathogenesis. Our findings provide significant insights into bacterial virulence mechanisms and disease. 相似文献