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111.
When a fossil vanishes to a private collection, it must be considered lost to science because, frequently, it is no longer available for study. Fortunately some fossils occasionally are regained. We had the opportunity to recoup an interesting footprint-bearing slab that was part of a private collection in Italy. The specimen, found in 1992 near Seligman, Arizona (USA) was described, before disappearing, as one of the best fossil examples of vertebrate (Chelichnus [Laoporus])-on-invertebrate (Octopodichnus) predation. After a careful re-examination of the slab, the primary conclusions of the former describers are demonstrably groundless. The reanalysis of the tracks, as well as peculiar sedimentary structures associated with the tracks, allowed obtaining new information about the depositional environment and the complex interactions between the type of substrate and trackmaker behavior. The re-examination of the specimen also revealed interesting aspects about trackmaker biomechanics. 相似文献
112.
Abstract Anemophylus dispersal of pollen grains in the Po Valley.—Results of phenological and aerobiological measurements with Castanea sativa pollen are presented. The data concerning the dispersal of this pollen in the Po Valley, show some features of the transport over hundred kilometer distances and give useful suggestions for application research. 相似文献
113.
Paolo Meletti 《Plant biosystems》2013,147(3-5):372-384
Abstract New perspectives in the study of factors which control seed germination. — Seedlings of Triticum durum, cv. « Cappelli », coming from unirradiated embryos grafted on to irradiated endosperms (EM(u)/EN(i) of presoaked seeds (in distilled water for 24 h. at 20[ddot]C.) (treatment: X-rays, doses, 2,4,6,8,10 and 20 Kr), grow more than seedlings of control EM(u)/EN(u) (dose 0) (fig. 1). To have this reaction, it is necessary that the used seeds be after-ripe; at the various stages of seed ripening, be ginning from the milk stage, the phenomenon is not present. On this basis, the author has thought that a natural inhibitor occurs in the after-ripe endosperm of « Cappelli », which is neutralized or destroyed by X-rays. As an experimental demonstration, some trials have been made of growing wheat seedlings in Petri dish, on moistened (distilled water) filter paper, together with excised embryos or isolated endosperms (fig. 2): the after-ripe endosperm is able to depress the seedling growth (fig. 3). In the same experimental conditions, X-rays, dose 6 Kr, neutralize the inhibition effect given by the endosperm. (fig. 4). A completely different situation occurs in wheat seed, during its ripening: endosperm is inactive, embryo produces inhibition effects on the seedling growth, which, also in this case, are reduced by X-rays. These phenomena, put in relation with dormancy in Triticum durum, cv. « Cappelli », which is a relative dormancy, having its maximum at the milk stage, have led the author to the general conclusion that, during dormancy, a germination inhibitor occurs in the embryo of wheat seed; when dormancy is finished, the inhibitor appears in the endosperm, in a situation which becomes stable and definitive. 相似文献
114.
Abstract Megagametophytes of Macrozamia communis were incubated in White's Basal Medium and in White's Basal Medium modified with 2,4-D and kinetin. On the medium enriched with growth substances, regeneration of coralloid roots was induced. These are morphologically identical to sporophytic coralloid roots, without any endosymbiont and displaying negative geotropism. These results confirm the fact that coralloid roots represent an inherent feature of the root system of the Cycadales rather than being the result of induction by microbial factors. Therefore it is possible to suggest that coralloid roots represent vestigial pneumatophores. 相似文献
115.
Nikos Papakonstantinou Stavroula Ntoufa Elisavet Chartomatsidou Giorgio Papadopoulos Artemis Hatzigeorgiou Achiles Anagnostopoulos Katerina Chlichlia Paolo Ghia Marta Muzio Chrysoula Belessi Kostas Stamatopoulos 《Molecular medicine (Cambridge, Mass.)》2013,19(1):115-123
Critical processes of B-cell physiology, including immune signaling through the B-cell receptor (BcR) and/or Toll-like receptors (TLRs), are targeted by microRNAs. With this in mind and also given the important role of BcR and TLR signaling and microRNAs in chronic lymphocytic leukemia (CLL), we investigated whether microRNAs could be implicated in shaping the behavior of CLL clones with distinct BcR and TLR molecular and functional profiles. To this end, we examined 79 CLL cases for the expression of 33 microRNAs, selected on the following criteria: (a) deregulated in CLL versus normal B-cells; (b) differentially expressed in CLL subgroups with distinct clinicobiological features; and, (c) if meeting (a) + (b), having predicted targets in the immune signaling pathways. Significant upregulation of miR-150, miR-29c, miR-143 and miR-223 and downregulation of miR-15a was found in mutated versus unmutated CLL, with miR-15a showing the highest fold difference. Comparison of two major subsets with distinct stereotyped BcRs and signaling signatures, namely subset 1 [IGHV1/5/7-IGKV1(D)-39, unmutated, bad prognosis] versus subset 4 [IGHV4-34/IGKV2-30, mutated, good prognosis] revealed differences in the expression of miR-150, miR-29b, miR-29c and miR-101, all down-regulated in subset 1. We were also able to link these distinct microRNA profiles with cellular phenotypes, importantly showing that, in subset 1, miR-101 downregulation is associated with overexpression of the enhancer of zeste homolog 2 (EZH2) protein, which has been associated with clinical aggressiveness in other B-cell lymphomas. In conclusion, specific miRNAs differentially expressed among CLL subgroups with distinct BcR and/or TLR signaling may modulate the biological and clinical behavior of the CLL clones. 相似文献
116.
Valentina Gambino Giulia De Michele Oriella Venezia Pierluigi Migliaccio Valentina Dall'Olio Loris Bernard Simone Paolo Minardi Maria Agnese Della Fazia Daniela Bartoli Giuseppe Servillo Myriam Alcalay Lucilla Luzi Marco Giorgio Heidi Scrable Pier Giuseppe Pelicci Enrica Migliaccio 《Aging cell》2013,12(3):435-445
117.
Valentina Sanghez Maria Teresa Russo Maria Antonietta Ajmone‐Cat Emanuele Cacci Alberto Martire Patrizia Popoli Germana Falcone Flavia Michelini Marco Crescenzi Paolo Degan Luisa Minghetti Margherita Bignami Gemma Calamandrei 《Aging cell》2013,12(4):695-705
The contribution that oxidative damage to DNA and/or RNA makes to the aging process remains undefined. In this study, we used the hMTH1‐Tg mouse model to investigate how oxidative damage to nucleic acids affects aging. hMTH1‐Tg mice express high levels of the hMTH1 hydrolase that degrades 8‐oxodGTP and 8‐oxoGTP and excludes 8‐oxoguanine from both DNA and RNA. Compared to wild‐type animals, hMTH1‐overexpressing mice have significantly lower steady‐state levels of 8‐oxoguanine in both nuclear and mitochondrial DNA of several organs, including the brain. hMTH1 overexpression prevents the age‐dependent accumulation of DNA 8‐oxoguanine that occurs in wild‐type mice. These lower levels of oxidized guanines are associated with increased longevity and hMTH1‐Tg animals live significantly longer than their wild‐type littermates. Neither lipid oxidation nor overall antioxidant status is significantly affected by hMTH1 overexpression. At the cellular level, neurospheres derived from adult hMTH1‐Tg neural progenitor cells display increased proliferative capacity and primary fibroblasts from hMTH1‐Tg embryos do not undergo overt senescence in vitro. The significantly lower levels of oxidized DNA/RNA in transgenic animals are associated with behavioral changes. These mice show reduced anxiety and enhanced investigation of environmental and social cues. Longevity conferred by overexpression of a single nucleotide hydrolase in hMTH1‐Tg animals is an example of lifespan extension associated with healthy aging. It provides a link between aging and oxidative damage to nucleic acids. 相似文献
118.
Alessandra Vacca Roberta Montisci Pietro Garau Paolo Siotto Matteo Piga Alberto Cauli Massimo Ruscazio Luigi Meloni Sabino Iliceto Alessandro Mathieu 《Arthritis research & therapy》2013,15(1):R8
Introduction
Microcirculation dysfunction is a typical feature of systemic sclerosis (SSc) and represents the earliest abnormality of primary myocardial involvement. We assessed coronary microcirculation status by combining two functional tests in SSc patients and estimating its impact on disease outcome.Methods
Forty-one SSc patients, asymptomatic for coronary artery disease, were tested for coronary flow velocity reserve (CFR) by transthoracic-echo-Doppler with adenosine infusion (A-TTE) and for left ventricular wall motion abnormalities (WMA) by dobutamine stress echocardiography (DSE). Myocardial multi-detector computed tomography (MDCT) enabled the presence of epicardial stenosis, which could interfere with the accuracy of the tests, to be excluded. Patient survival rate was assessed over a 6.7- ± 3.5-year follow-up.Results
Nineteen out of 41 (46%) SSc patients had a reduced CFR (≤2.5) and in 16/41 (39%) a WMA was observed during DSE. Furthermore, 13/41 (32%) patients showed pathological CFR and WMA. An inverse correlation between wall motion score index (WMSI) during DSE and CFR value (r = -0.57, P <0.0001) was observed; in addition, CFR was significantly reduced (2.21 ± 0.38) in patients with WMA as compared to those without (2.94 ± 0.60) (P <0.0001). In 12 patients with abnormal DSE, MDCT was used to exclude macrovasculopathy. During a 6.7- ± 3.5-year follow-up seven patients with abnormal coronary functional tests died of disease-related causes, compared to only one patient with normal tests.Conclusions
A-TTE and DSE tests are useful tools to detect non-invasively pre-clinical microcirculation abnormalities in SSc patients; moreover, abnormal CFR and WMA might be related to a worse disease outcome suggesting a prognostic value of these tests, similar to other myocardial diseases. 相似文献119.
The genus Cleptes Latreille, 1802 from China is revised and illustrated for the first time. Seventeen species of Cleptes are recorded. Nine species are new to science, Cleptes albonotatus
sp. n., Cleptes eburnecoxis
sp. n., Cleptes flavolineatus
sp. n., Cleptes helanshanus
sp. n., Cleptes niger
sp. n., Cleptes shengi
sp. n., Cleptes sinensis
sp. n., Cleptes tibetensis
sp. n., and Cleptes villosus
sp. n.,and two species are reported as new to China, Cleptes metallicorpus Ha, Lee & Kim, 2011, and Cleptes seoulensis Tsuneki, 1959. 相似文献
120.
Suleeporn Sangrajrang Peter Schmezer Iris Burkholder Paolo Boffetta Paul Brennan Andreas Woelfelschneider 《Biomarkers》2013,18(5):523-532
The X-ray repair cross-complementing group 3 gene (XRCC3) belongs to a family of genes responsible for repairing DNA double-strand breaks caused by normal metabolic processes and exposure to ionizing radiation. Polymorphisms in DNA repair genes may alter an individual's capacity to repair damaged DNA and may lead to genetic instability and contribute to malignant transformation. We examined the role of a polymorphism in the XRCC3 gene (rs861529; codon 241: threonine to methionine change) in determining breast cancer risk in Thai women. The study population consisted of 507 breast cancer cases and 425 healthy women. The polymorphism was analysed by fluorescence-based melting curve analysis. The XRCC3 241Met allele was found to be uncommon in the Thai population (frequency 0.07 among cases and 0.05 among controls). Odds ratios (OR) adjusted for age, body mass index, age at menarche, family history of breast cancer, menopausal status, reproduction parameters, use of contraceptives, tobacco smoking, involuntary tobacco smoking, alcohol drinking, and education were calculated for the entire population as well as for pre- and postmenopausal women. There was a significant association between 241Met carrier status and breast cancer risk (OR 1.58, 95% confidence interval (CI) 1.02–2.44). Among postmenopausal women, a slightly higher OR (1.82, 95% CI 0.95–3.51) was found than among premenopausal women (OR 1.48, 95% CI 0.82–2.69). Our findings suggest that the XRCC3 Thr241Met polymorphism is likely to play a modifying role in the individual susceptibility to breast cancer among Thai women as already shown for women of European ancestry. 相似文献