全文获取类型
收费全文 | 2069篇 |
免费 | 129篇 |
国内免费 | 2篇 |
出版年
2023年 | 10篇 |
2022年 | 9篇 |
2021年 | 40篇 |
2020年 | 22篇 |
2019年 | 41篇 |
2018年 | 44篇 |
2017年 | 38篇 |
2016年 | 63篇 |
2015年 | 99篇 |
2014年 | 107篇 |
2013年 | 140篇 |
2012年 | 169篇 |
2011年 | 166篇 |
2010年 | 97篇 |
2009年 | 93篇 |
2008年 | 132篇 |
2007年 | 121篇 |
2006年 | 115篇 |
2005年 | 100篇 |
2004年 | 108篇 |
2003年 | 92篇 |
2002年 | 95篇 |
2001年 | 19篇 |
2000年 | 12篇 |
1999年 | 18篇 |
1998年 | 10篇 |
1997年 | 18篇 |
1996年 | 10篇 |
1995年 | 8篇 |
1994年 | 13篇 |
1993年 | 14篇 |
1992年 | 16篇 |
1991年 | 5篇 |
1990年 | 15篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 9篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1969年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有2200条查询结果,搜索用时 15 毫秒
91.
Claudio Battilocchio Giovanna Poce Salvatore Alfonso Giulio Cesare Porretta Sara Consalvi Lidia Sautebin Simona Pace Antonietta Rossi Carla Ghelardini Lorenzo Di Cesare Mannelli Silvia Schenone Antonio Giordani Luigia Di Francesco Paola Patrignani Mariangela Biava 《Bioorganic & medicinal chemistry》2013,21(13):3695-3701
We report the synthesis and bio-pharmacological evaluation of a class of pyrrole derivatives featuring a small appendage fragment (carbaldehyde, oxime, nitrile) on the central core. Compound 1c proved to be extremely effective in vivo, showing an interesting anti-nociceptic profile that is comparable to reference compounds already marketed, hence representing a great stimulus for a further improvement of this class of molecules. 相似文献
92.
Domenico Schillaci Salvatore Petruso Maria Valeria Raimondi Maria Grazia Cusimano Stella Cascioferro Marianna Scalisi 《Biofouling》2013,29(4):433-438
With the goal of discovering new anti-infective agents active against microbial biofilms, this investigation focused on some natural pyrrolomycins, a family of halogenated pyrrole antibiotics. In this study the anti-staphylococcal biofilm activity of pyrrolomycins C, D, F1, F2a, F2b, F3 and of the synthesized related compounds I, II, III were investigated. The susceptibility of six staphylococcal biofilms was determined by methyltiazotetrazolium staining. Most of the compounds were active at concentrations of 1.5 μg ml?1 with significant inhibition percentages. A few of the compounds were active at the lowest screening concentration of 0.045 μg ml?1. The population log reduction of activity against the two best biofilm forming Staphylococcus aureus strains as determined by viable plate counts is also reported. In order to adequately assess the utility of these compounds, their toxicity against human cells was evaluated. It is concluded that pyrrolomycins and synthetic derivatives are promising compounds for developing novel effective chemical countermeasures against staphylococcal biofilms. 相似文献
93.
Sang-Kuy Han Salvatore Federico 《Computer methods in biomechanics and biomedical engineering》2013,16(7):657-664
Experimental studies suggest that the magnitude of chondrocyte deformation is much smaller than expected based on the material properties of extracellular matrix (ECM) and cells, and that this result could be explained by a structural unit, the chondron, that is thought to protect chondrocytes from large deformations in situ. We extended an existing numerical model of chondrocyte, ECM and pericellular matrix (PCM) to include depth-dependent structural information. Our results suggest that superficial zone chondrocytes, which lack a pericellular capsule (PC), are relatively stiff, and therefore are protected from excessive deformations, whereas middle and deep zone chondrocytes are softer but are protected by the PC that limits cell deformations in these regions. We conclude that cell deformations sensitively depend on the immediate structural environment of the PCM in a depth-dependent manner, and that the functional stiffness of chondrocytes in situ is much larger than experiments on isolated cells would suggest. 相似文献
94.
Sylvia Kamphuis Kolbrún Hrafnkelsdóttir Mark R Klein Wilco de Jager Margje H Haverkamp Jolanda HM van Bilsen Salvatore Albani Wietse Kuis Marca HM Wauben Berent J Prakken 《Arthritis research & therapy》2007,8(6):R178
Juvenile idiopathic arthritis (JIA) is a heterogeneous autoimmune disease characterized by chronic joint inflammation. Knowing
which antigens drive the autoreactive T-cell response in JIA is crucial for the understanding of disease pathogenesis and
additionally may provide targets for antigen-specific immune therapy. In this study, we tested 9 self-peptides derived from
joint-related autoantigens for T-cell recognition (T-cell proliferative responses and cytokine production) in 36 JIA patients
and 15 healthy controls. Positive T-cell proliferative responses (stimulation index ≥2) to one or more peptides were detected
in peripheral blood mononuclear cells (PBMC) of 69% of JIA patients irrespective of major histocompatibility complex (MHC)
genotype. The peptides derived from aggrecan, fibrillin, and matrix metalloproteinase (MMP)-3 yielded the highest frequency
of T-cell proliferative responses in JIA patients. In both the oligoarticular and polyarticular subtypes of JIA, the aggrecan
peptide induced T-cell proliferative responses that were inversely related with disease duration. The fibrillin peptide, to
our knowledge, is the first identified autoantigen that is primarily recognized in polyarticular JIA patients. Finally, the
epitope derived from MMP-3 elicited immune responses in both subtypes of JIA and in healthy controls. Cytokine production
in short-term peptide-specific T-cell lines revealed production of interferon-γ (aggrecan/MMP-3) and interleukin (IL)-17 (aggrecan)
and inhibition of IL-10 production (aggrecan). Here, we have identified a triplet of self-epitopes, each with distinct patterns
of T-cell recognition in JIA patients. Additional experiments need to be performed to explore their qualities and role in
disease pathogenesis in further detail. 相似文献
95.
Salvatore Andini Ettore Benedetti Luciano Ferrara Livio Paolillo Piero Andrea Temussi 《Origins of life and evolution of the biosphere》1975,6(1-2):147-153
Several polypeptides prepared by means of pyrocondensation have been the subject of structural investigations. Attention has been focused on the constitutional characterization of homo-and co-polymers containing Asp and Glu residues, whose role is essential for the formation of the so-called proteinoids. Contrary to the literature data based on chemical degradation, nmr studies show conclusively that in thermal poly-aspartic acid only β-peptide linkages are present. This result casts serious doubt on the role thermal condensation might have played in prebiotic polypeptide syntheses. 相似文献
96.
[3H]-cocaine, [3H]-norcocaine, [3H]-benzoylecgonine and [3H]-benzoylnorecgonine were administered i.c. in equi-potent pharmacologic doses and the intracellular disposition and metabolism of each drug determined. Norcocaine and cocaine rapidly entered and egressed from the brain so that 4.8–6.1% of the radioactivity present in brain at one minute was observed at 30 minutes. The highest levels of subcellular radioactivity were generally found in the microsomal plus supernatant, followed by the nuclear and shocked mitochondrial fractions. No apparent localization of the radioactivity occured in synaptic membranes. The brain/plasma (B/P) ratio curves for cocaine and norcocaine were similar; however, the norcocaine values were considerably higher at each time interval. Benzoylecgonine and benzoylnorecgonine had higher comparative B/P ratios than cocaine or norcocaine and persisted in brain for a longer period of time so that 0.6–2.1% of the radioactivity present in brain at 1 hour was detected at 24 hours. Cocaine and norcocaine were extensively metabolized to the benzoylmetabolites. Benzoylecgonine was metabolized to benzoylnorecgonine and benzoylnorecgonine was unmetabolized. The brain disposition data and B/P ratios agreed quite well with the overall pharmacologic action of cocaine and its metabolites. 相似文献
97.
98.
Sbragaglia Valerio Espasandín Lucía Coco Salvatore Felici Alberto Correia Ricardo A. Coll Marta Arlinghaus Robert 《Reviews in Fish Biology and Fisheries》2022,32(2):687-700
Reviews in Fish Biology and Fisheries - Fisheries are among the human activities that are most strongly affected by ongoing climate-related changes in the presence and abundance of fish species... 相似文献
99.
Scribano Vittorio Simakov Sergei K. Finocchiaro Claudio Correale Alessandra Scirè Salvatore 《Origins of life and evolution of the biosphere》2019,49(1-2):19-47
Origins of Life and Evolution of Biospheres - Pyrite and organic matter closely coexist in some hydrothermally-altered gabbroic xenoliths from the Hyblean Plateau, Sicily. The representative sample... 相似文献
100.
A new species of willow from Crete, named Salix kaptarae Cambria, C. Brullo & Brullo, is described and illustrated. Morphologically, it shows close relationships with species belonging to the S. apennina group, mainly with respect to the leaf shape, and the hairy ovary, capsule and base of stamina filaments. Considerations on its ecology, leaf micro‐morphology and conservation status are also provided. 相似文献