全文获取类型
收费全文 | 906篇 |
免费 | 35篇 |
专业分类
941篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 12篇 |
2017年 | 9篇 |
2016年 | 23篇 |
2015年 | 30篇 |
2014年 | 62篇 |
2013年 | 65篇 |
2012年 | 85篇 |
2011年 | 124篇 |
2010年 | 91篇 |
2009年 | 81篇 |
2008年 | 51篇 |
2007年 | 50篇 |
2006年 | 51篇 |
2005年 | 40篇 |
2004年 | 27篇 |
2003年 | 28篇 |
2002年 | 24篇 |
2001年 | 4篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有941条查询结果,搜索用时 15 毫秒
31.
32.
Chertkov O Sikorski J Nolan M Lapidus A Lucas S Del Rio TG Tice H Cheng JF Goodwin L Pitluck S Liolios K Ivanova N Mavromatis K Mikhailova N Ovchinnikova G Pati A Chen A Palaniappan K Djao OD Land M Hauser L Chang YJ Jeffries CD Brettin T Han C Detter JC Rohde M Göker M Woyke T Bristow J Eisen JA Markowitz V Hugenholtz P Klenk HP Kyrpides NC 《Standards in genomic sciences》2011,4(1):13-22
Thermomonospora curvata Henssen 1957 is the type species of the genus Thermomonospora. This genus is of interest because members of this clade are sources of new antibiotics, enzymes, and products with pharmacological activity. In addition, members of this genus participate in the active degradation of cellulose. This is the first complete genome sequence of a member of the family Thermomonosporaceae. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 5,639,016 bp long genome with its 4,985 protein-coding and 76 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project. 相似文献
33.
Nikos T. Papadopoulos Todd E. Shelly Nuri Niyazi Eric Jang 《Journal of Insect Behavior》2006,19(3):403-418
Males of the Mediterranean fruit fly, Ceratitis capitata, are strongly attracted to various plant odors, and previous work has demonstrated that male exposure to certain odors, including the scent of orange oil (OO) and ginger root oil (GRO), increases their mating success relative to non-exposed males. However, the mechanism(s) underlying this mating increase is not known. Here, we describe several experiments that further investigate the association between GRO- and OO-exposure and male signaling activity, pheromone attractiveness, and mating success in male medflies. Exposure to GRO or OO increased time spent pheromone calling but did not accelerate the rate of male sexual maturation. Using a wind tunnel, we compared female attraction to the pheromone of control, non-exposed males versus males previously exposed to OO or GRO. There was no evidence that GRO exposure enhanced the attractiveness of the male pheromone. The data for OO were inconclusive: females tended to spend more time on spheres emanating pheromone from OO-exposed males than on spheres emanating pheromone from non-exposed males, but the number of female landings did not differ between the two types of pheromone sources. Female choice tests confirmed that GRO- and OO-exposure boost male mating success relative to non-exposed males. Application of GRO directly to the abdomen reduced male mating success, whereas similar application of OO boosted male mating success. The potential role and mode of action of plant chemicals in the mating behavior of male medflies are evaluated in light of these findings. 相似文献
34.
Inter‐Fullerene Electronic Coupling Controls the Efficiency of Photoinduced Charge Generation in Organic Bulk Heterojunctions 下载免费PDF全文
Bryon W. Larson Obadiah G. Reid David C. Coffey Stanislav M. Avdoshenko Alexey A. Popov Olga V. Boltalina Steven H. Strauss Nikos Kopidakis Garry Rumbles 《Liver Transplantation》2016,6(24)
Photoinduced charge generation (PCG) dynamics are notoriously difficult to correlate with specific molecular properties in device relevant polymer:fullerene organic photovoltaic blend films due to the highly complex nature of the solid state blend morphology. Here, this study uses six judiciously selected trifluoromethylfullerenes blended with the prototypical polymer poly(3‐hexylthiophene) and measure the PCG dynamics in 50 fs–500 ns time scales with time‐resolved microwave conductivity and femtosecond transient absorption spectroscopy. The isomeric purity and thorough chemical characterization of the fullerenes used in this study allow for a detailed correlation between molecular properties, driving force, local intermolecular electronic coupling and, ultimately, the efficiency of PCG yield. The findings show that the molecular design of the fullerene not only determines inter‐fullerene electronic coupling, but also influences the decay dynamics of free holes in the donor phase even when the polymer microstructure remains unchanged. 相似文献
35.
David A. Mead Susan Lucas Alex Copeland Alla Lapidus Jan-Feng Cheng David C. Bruce Lynne A. Goodwin Sam Pitluck Olga Chertkov Xiaojing Zhang John C. Detter Cliff S. Han Roxanne Tapia Miriam Land Loren J. Hauser Yun-juan Chang Nikos C. Kyrpides Natalia N. Ivanova Galina Ovchinnikova Tanja Woyke Catherine Brumm Rebecca Hochstein Thomas Schoenfeld Phillip Brumm 《Standards in genomic sciences》2012,6(3):381-400
36.
Theocharis AD Seidel C Borset M Dobra K Baykov V Labropoulou V Kanakis I Dalas E Karamanos NK Sundan A Hjerpe A 《The Journal of biological chemistry》2006,281(46):35116-35128
Although the biological significance of proteoglycans (PGs) has previously been highlighted in multiple myeloma (MM), little is known about serglycin, which is a hematopoietic cell granule PG. In this study, we describe the expression and highly constitutive secretion of serglycin in several MM cell lines. Serglycin messenger RNA was detected in six MM cell lines. PGs were purified from conditioned medium of four MM cell lines, and serglycin substituted with 4-sulfated chondroitin sulfate was identified as the predominant PG. Flow cytometry and confocal microscopy showed that serglycin was also present intracellularly and on the cell surface, and attachment to the cell surface was at least in part dependent on intact glycosaminoglycan side chains. Immunohistochemical staining of bone marrow biopsies showed the presence of serglycin both in benign and malignant plasma cells. Immunoblotting in bone marrow aspirates from a limited number of patients with newly diagnosed MM revealed highly increased levels of serglycin in 30% of the cases. Serglycin isolated from myeloma plasma cells was found to influence the bone mineralization process through inhibition of the crystal growth rate of hydroxyapatite. This rate reduction was attributed to adsorption and further blocking of the active growth sites on the crystal surface. The apparent order of the crystallization reaction was found to be n=2, suggesting a surface diffusion-controlled spiral growth mechanism. Our findings suggest that serglycin release is a constitutive process, which may be of fundamental biological importance in the study of MM. 相似文献
37.
Neurophysiology of the BOLD fMRI signal in awake monkeys 总被引:3,自引:0,他引:3
BACKGROUND: Simultaneous intracortical recordings of neural activity and blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) in primary visual cortex of anesthetized monkeys demonstrated varying degrees of correlation between fMRI signals and the different types of neural activity, such as local field potentials (LFPs), multiple-unit activity (MUA), and single-unit activity (SUA). One important question raised by the aforementioned investigation is whether the reported correlations also apply to alert subjects. RESULTS: Monkeys were trained to perform a fixation task while stimuli within the receptive field of each recording site were used to elicit neural responses followed by a BOLD response. We show -- also in alert behaving monkeys -- that although both LFP and MUA make significant contributions to the BOLD response, LFPs are better and more reliable predictors of the BOLD signal. Moreover, when MUA responses adapt but LFP remains unaffected, the BOLD signal remains unaltered. CONCLUSIONS: The persistent coupling of the BOLD signal to the field potential when LFP and MUA have different time evolutions suggests that BOLD is primarily determined by the local processing of inputs in a given cortical area. In the alert animal the largest portion of the BOLD signal's variance is explained by an LFP range (20-60 Hz) that is most likely related to neuromodulation. Finally, the similarity of the results in alert and anesthetized subjects indicates that at least in V1 anesthesia is not a confounding factor. This enables the comparison of human fMRI results with a plethora of electrophysiological results obtained in alert or anesthetized animals. 相似文献
38.
Athanasios K. Anagnostopoulos Aggeliki Kolialexi Ariadni Mavrou Konstantinos Vougas Nikos Papantoniou Aris Antsaklis Emmanuel Kanavakis Michael Fountoulakis George Th. Tsangaris 《Journal of Proteomics》2010,73(5):943-950
Klinefelter syndrome is a sex chromosomal abnormality (47, XXY karyotype), occurring approximately in 1 in 1000 male live births. In the present study proteomic analysis was performed in twelve 2nd trimester amniotic fluid samples, eight coming from pregnancies with normal males and four with Klinefelter syndrome foetuses, as shown by routine prenatal cytogenetic analysis. Samples were analysed by 2-DE, coupled with MALDI-TOF-MS analysis. Three proteins (Ceruloplasmin, Alpha-1-antitrypsin and Zinc-alpha-2-glycoprotein) were found to be up-regulated in samples obtained from pregnancies with Klinefelter syndrome foetuses, whereas four proteins (Apolipoprotein A-I, Plasma retinol-binding protein, Gelsolin, and Vitamin D-binding protein) were down regulated when compared to proteins detected in samples from normal foetuses. The differential expression of Ceruloplasmin, Apolipoprotein A-I and Plasma retinol-binding protein was further confirmed by immunoblotting. Since these proteins are likely to cross the placenta barrier and be detected in maternal plasma they could be used as biomarkers for the non-invasive prenatal diagnosis of Klinefelter syndrome. 相似文献
39.
Hemme CL Mouttaki H Lee YJ Zhang G Goodwin L Lucas S Copeland A Lapidus A Glavina del Rio T Tice H Saunders E Brettin T Detter JC Han CS Pitluck S Land ML Hauser LJ Kyrpides N Mikhailova N He Z Wu L Van Nostrand JD Henrissat B He Q Lawson PA Tanner RS Lynd LR Wiegel J Fields MW Arkin AP Schadt CW Stevenson BS McInerney MJ Yang Y Dong H Xing D Ren N Wang A Huhnke RL Mielenz JR Ding SY Himmel ME Taghavi S van der Lelie D Rubin EM Zhou J 《Journal of bacteriology》2010,192(24):6494-6496
Modern methods to develop microbe-based biomass conversion processes require a system-level understanding of the microbes involved. Clostridium species have long been recognized as ideal candidates for processes involving biomass conversion and production of various biofuels and other industrial products. To expand the knowledge base for clostridial species relevant to current biofuel production efforts, we have sequenced the genomes of 20 species spanning multiple genera. The majority of species sequenced fall within the class III cellulosome-encoding Clostridium and the class V saccharolytic Thermoanaerobacteraceae. Species were chosen based on representation in the experimental literature as model organisms, ability to degrade cellulosic biomass either by free enzymes or by cellulosomes, ability to rapidly ferment hexose and pentose sugars to ethanol, and ability to ferment synthesis gas to ethanol. The sequenced strains significantly increase the number of noncommensal/nonpathogenic clostridial species and provide a key foundation for future studies of biomass conversion, cellulosome composition, and clostridial systems biology. 相似文献
40.
Mavromatis K Abt B Brambilla E Lapidus A Copeland A Deshpande S Nolan M Lucas S Tice H Cheng JF Han C Detter JC Woyke T Goodwin L Pitluck S Held B Brettin T Tapia R Ivanova N Mikhailova N Pati A Liolios K Chen A Palaniappan K Land M Hauser L Chang YJ Jeffries CD Rohde M Göker M Bristow J Eisen JA Markowitz V Hugenholtz P Klenk HP Kyrpides NC 《Standards in genomic sciences》2010,2(3):290-299
Coraliomargarita akajimensis Yoon et al. 2007 is the type species of the genus Coraliomargarita. C. akajimensis is an obligately aerobic, Gram-negative, non-spore-forming, non-motile, spherical bacterium that was isolated from seawater surrounding the hard coral Galaxea fascicularis. C. akajimensis is of special interest because of its phylogenetic position in a genomically under-studied area of the bacterial diversity. Here we describe the features of this organism, together with the complete genome sequence, and annotation. This is the first complete genome sequence of a member of the family Puniceicoccaceae. The 3,750,771 bp long genome with its 3,137 protein-coding and 55 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project. 相似文献