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41.
Antonov AS Avilov SA Kalinovsky AI Anastyuk SD Dmitrenok PS Evtushenko EV Kalinin VI Smirnov AV Taboada S Ballesteros M Avila C Stonik VA 《Journal of natural products》2008,71(10):1677-1685
Five new triterpene glycosides, liouvillosides A1 (1), A2 (2), A3 (3), B1 (4), and B2 (5), have been isolated from the Antarctic sea cucumber Staurocucumis liouviellei along with the known liouvilloside A(6), isolated earlier from the same species, and hemoiedemosides A (7) and B (8), isolated earlier from the Patagonian sea cucumber Hemioedema spectabilis. The isolation was carried out using a new chromatographic procedure including application of ion-pair reversed-phase chromatography followed by chiral chromatography on a cyclodextrin ChiraDex column. The structures of the new glycosides were elucidated using extensive NMR spectroscopy (1H and 13C NMR spectrometry, DEPT, 1H-(1)H COSY, HMBC, HMQC, and NOESY), ESI-FTMS, and CID MS/MS, and chemical transformations. Glycosides 1-3 are disulfated tetraosides and glycosides 4 and 5 are trisulfated tetraosides. Glycosides 2 and 3 contain 3-O-methylquinovose, found for the first time as a natural monosaccharide in sea cucumber glycosides. On the basis of analyses of glycoside structures a taxonomic revision is proposed. 相似文献
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Liang H Chaparro-Riggers J Strop P Geng T Sutton JE Tsai D Bai L Abdiche Y Dilley J Yu J Wu S Chin SM Lee NA Rossi A Lin JC Rajpal A Pons J Shelton DL 《The Journal of pharmacology and experimental therapeutics》2012,340(2):228-236
Proprotein convertase substilisin/kexin type 9 (PCSK9) promotes the degradation of low-density lipoprotein (LDL) receptor (LDLR) and thereby increases serum LDL-cholesterol (LDL-C). We have developed a humanized monoclonal antibody that recognizes the LDLR binding domain of PCSK9. This antibody, J16, and its precursor mouse antibody, J10, potently inhibit PCSK9 binding to the LDLR extracellular domain and PCSK9-mediated down-regulation of LDLR in vitro. In vivo, J10 effectively reduces serum cholesterol in C57BL/6 mice fed normal chow. J16 reduces LDL-C in healthy and diet-induced hypercholesterolemic cynomologous monkeys, but does not significantly affect high-density lipoprotein-cholesterol. Furthermore, J16 greatly lowered LDL-C in hypercholesterolemic monkeys treated with the HMG-CoA reductase inhibitor simvastatin. Our data demonstrate that anti-PCSK9 antibody is a promising LDL-C-lowering agent that is both efficacious and potentially additive to current therapies. 相似文献
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Tatiana S. Demina Anastasia S. Kuryanova Nadejda A. Aksenova Andrey G. Shubnyy Tatiana N. Popyrina Yaroslav V. Sokovikov Elena V. Istranova Pavel L. Ivanov Peter S. Timashev Tatiana A. Akopova 《RSC advances》2019,9(64):37652
Graft-copolymers based on bioresorbable synthetic (oligo-/polylactide) and natural (chitosan and collagen/gelatin) components were synthesized through solid-state reactive co-extrusion and used for fabrication of fibrous non-woven mats via the electrospinning technique. The effect of the macromolecular features of the initial components on the copolymer characteristics was evaluated using FTIR-spectroscopy, differential scanning calorimetry and elemental analysis. Dynamic light scattering analysis showed that the copolymers have a tendency to form stable ultra-fine dispersions with a mean size of macromolecular aggregates of 150 nm within chlorinated solvents. The copolymer-containing non-woven fibrous mats were fabricated via an electrospinning procedure using chloroform as a solvent. An effect of the copolymer composition on the casting solution''s viscosity, conductivity and surface tension was evaluated. Scanning electron microscopy showed that the obtained mats consist of randomly distributed fibers with a mean size of ∼5 μm and a more complex morphology than mats fabricated from neat polylactide. The proposed mechanochemical approach to obtain hybrid copolymeric compositions differs from typical liquid-phase methods in terms of high efficiency, simplicity and cleanness.Amphiphilic chitosan-g-oligo/polylactide graft-copolymers were synthesized through solid-state reactive co-extrusion and used for fabrication of fibrous non-woven mats via the electrospinning technique using chloroform as a solvent. 相似文献
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Human and mouse genomic sequences reveal extensive breakpoint reuse in mammalian evolution 总被引:23,自引:0,他引:23 下载免费PDF全文
Pevzner P Tesler G 《Proceedings of the National Academy of Sciences of the United States of America》2003,100(13):7672-7677
The human and mouse genomic sequences provide evidence for a larger number of rearrangements than previously thought and reveal extensive reuse of breakpoints from the same short fragile regions. Breakpoint clustering in regions implicated in cancer and infertility have been reported in previous studies; we report here on breakpoint clustering in chromosome evolution. This clustering reveals limitations of the widely accepted random breakage theory that has remained unchallenged since the mid-1980s. The genome rearrangement analysis of the human and mouse genomes implies the existence of a large number of very short "hidden" synteny blocks that were invisible in the comparative mapping data and ignored in the random breakage model. These blocks are defined by closely located breakpoints and are often hard to detect. Our results suggest a model of chromosome evolution that postulates that mammalian genomes are mosaics of fragile regions with high propensity for rearrangements and solid regions with low propensity for rearrangements. 相似文献
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Daniele Campa Cosmeri Rizzato Gabriele Capurso Nathalia Giese Niccola Funel William Greenhalf Pavel Soucek Maria Gazouli Raffaele Pezzilli Claudio Pasquali Renata Talar-Wojnarowska Maurizio Cantore Angelo Andriulli Aldo Scarpa Krzysztof Jamroziak Gianfranco Delle Fave Eithne Costello Kay-Tee Khaw Federico Canzian 《Digestive and liver disease》2013,45(2):95-99
Pancreatic cancer is the fourth leading cause of cancer deaths in the European Union and in the USA, but little is known about its genetic susceptibility. The PANcreatic Disease ReseArch (PANDoRA) consortium was established to unite the efforts of different research groups; its aim is to create a large bio-database to uncover new genetic factors for pancreatic cancer risk, response to treatment, and patient survival. So far 2220 cases of pancreatic adenocarcinoma, a smaller number of cases of endocrine pancreatic tumours (n = 86), chronic pancreatitis (n = 272) and 3847 healthy controls have been collected. As a collective effort of the consortium, SNPs associated with pancreatic adenocarcinoma risk from a genome-wide association study performed in Caucasians were replicated. The possibility that the same genetic polymorphisms may influence patient survival as well was also addressed. This collective effort is particularly important for pancreatic cancer because it is a relatively rare disease for which little is known about aetiopathogenesis and risk factors. The recruitment of additional collaborators and partner institutions is continuously on-going. 相似文献
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Synthesis and Gas‐Transport Properties of Metathesis Polytricyclononenes Bearing Three Me3Si Groups per Monomer Unit 下载免费PDF全文
Pavel Chapala Maxim Bermeshev Ludmila Starannikova Ilya Borisov Viktor Shantarovich Valentin Lakhtin Vladimir Volkov Eugene Finkelshtein 《Macromolecular chemistry and physics.》2016,217(17):1966-1976
A new metathesis polynorbornene containing three SiMe3 groups per monomer unit directly connected to the norbornene moiety via Si? C bonds is synthesized. The ring‐opening metathesis polymerization of sterically hindered 3,3,4‐tris(trimethylsilyl)tricyclononene‐7 is successfully conducted in yields 80–85% in the presence of first generation Grubbs catalyst. The corresponding polymer is obtained with molecular weight Mw up to 5.4 × 105 Da. It is an amorphous glassy (Tg = 200 °C) polymer with high thermal stability. Gas permeability and diffusivity coefficients are studied for a range of gases (He, H2, O2, N2, CO2, CH4). This polymer containing three SiMe3 groups per monomer unit turns out to be more permeable (P(O2) = 125 Barrer) than similar polymers with one or two SiMe3 groups per monomer unit (P(O2) = 30–50 Barrer). Wide angle X‐ray diffraction, positron annihilating lifetime spectroscopy, as well as Brunauer–Emmett–Teller investigations are also performed and discussed.