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排序方式: 共有235条查询结果,搜索用时 31 毫秒
1.
Butow Barbara; Wynne David; Sukenik Assaf; Hadas Ora; Tel-Or Elisha 《Journal of plankton research》1998,20(2):355-369
Lipid peroxidation in Peridinium samples taken from two differentdepths in Lake Kinneret fluctuated throughout the spring withan overall increasing trend. Samples from 0.5 and 5 m showeda similar peroxidation pattern, which was maximal after thefall off in algal biomass. The rapid decline in Peridinium biomasscoincided with ambient lake temperatures of 2123C. Fattyacid composition profiles were similar at both depths, althoughafter the peak of the bloom, a significant increase in polyunsaturatedfatty acids and oleic acid was only found at 0.5 m, togetherwith a decrease in the percentage of polyunsaturated fatty acids.These effects were related to ambient light stress rather thana result of lipid peroxidation. Lake samples taken at differentperiods of the bloom and incubated at various temperatures showeddifferential peroxidation. Higher temperatures caused increasedlipid peroxidation, but this appeared to be dependent on thesampling period. Samples withdrawn from the lake at the beginningof the bloom showed little peroxidation after a 5 day incubationat 14C, room temperature (25C) or ambient lake temperature(16C) compared to mid-bloom samples in which there was a significantincrease in peroxidation when they were incubated at room temperature(25C) or ambient lake temperature (22C). Incubation at 14Cinhibited peroxidation; however, samples from mid-bloom againshowed enhanced peroxidation compared with those from the beginningof the bloom. These in situ results suggested a relationshipbetween temperature, another environmental variable during thebloom and lipid peroxidation in Peridinium. As total dissolvedinorganic carbon (DIC) concentrations fall significantly duringthe progress of the bloom and represent an important sourceof environmental stress, laboratory experiments were establishedto investigate the synergistic effect of temperature and carbonnutrition on lipid peroxidation in Peridinium cultures. Increasedtemperature alone caused a slight increase in lipid peroxidation,but this was greatly augmented by carbon limitation. Althoughcarbon limitation induced increased catalase activity, at highertemperatures activity declined after 48 h, allowing for thesubstantial increase in lipid peroxidation. 相似文献
2.
Acetylcholinesterase activity of human erythrocytes is known to be inhibited by linolenoyl sorbitol, the inhibition being critically dependent on cell membrane intactness. The extent of enzyme inhibition by the added lipid is correlated with the magnitude of Cl? gradient across the erythrocyte membrane, indicating that enzyme sensitivity is associated with a transmembrane potential. If linolenoyl sorbitol is allowed to interact with the erythrocytes while a Cl? gradient exists, enzyme sensitivity can subsequently be demonstrated not only in the absence of a gradient but even when the cells are lyzed. It is concluded that the transmembrane potential determines the accessibility of a membrane component to the added lipid. 相似文献
3.
Means to increase the reproductive capacity of Crocus sativus L., in vitro, are described. Cytokinins and auxin were found to be essential for development of bud explants. Ethylene and ethaphon pretreatments inhibited leaf development but induced corm production. Microsurgery of the apical bud combined with ethylene pretreatment increased both sprouting and corm production. 相似文献
4.
Drug resistance is a major obstacle for the successful treatment of many malignancies, including neuroblastoma, the most common extracranial solid tumor in childhood. Therefore, current attempts to improve the survival of neuroblastoma patients, as well as those with other cancers, largely depend on strategies to counter cancer cell drug resistance; hence, it is critical to understand the molecular mechanisms that mediate resistance to chemotherapeutics. The levels of LIM-kinase 2 (LIMK2) are increased in neuroblastoma cells selected for their resistance to microtubule-targeted drugs, suggesting that LIMK2 might be a possible target to overcome drug resistance. Here, we report that depletion of LIMK2 sensitizes SHEP neuroblastoma cells to several microtubule-targeted drugs, and that this increased sensitivity correlates with enhanced cell cycle arrest and apoptosis. Furthermore, we show that LIMK2 modulates microtubule acetylation and the levels of tubulin Polymerization Promoting Protein 1 (TPPP1), suggesting that LIMK2 may participate in the mitotic block induced by microtubule-targeted drugs through regulation of the microtubule network. Moreover, LIMK2-depleted cells also show an increased sensitivity to certain DNA-damage agents, suggesting that LIMK2 might act as a general pro-survival factor. Our results highlight the exciting possibility of combining specific LIMK2 inhibitors with anticancer drugs in the treatment of multi-drug resistant cancers. 相似文献
5.
6.
Dae Won Kim Sung Ho Lee Min Jea Shin Kibom Kim Sae Kwang Ku Jong Kyu Youn Su Bin Cho Jung Hwan Park Chi Hern Lee Ora Son Eun Jeong Sohn Sung-Woo Cho Jong Hoon Park Hyun Ah Kim Kyu Hyung Han Jinseu Park Won Sik Eum Soo Young Choi 《BMB reports》2015,48(11):618-623
FK506 binding protein 12 (FK506BP) is a small peptide with a single FK506BP domain that is involved in suppression of immune response and reactive oxygen species. FK506BP has emerged as a potential drug target for several inflammatory diseases. Here, we examined the protective effects of directly applied cell permeable FK506BP (PEP-1-FK506BP) on corneal alkali burn injury (CAI). In the cornea, there was a significant decrease in the number of cells expressing pro-inflammation, apoptotic, and angiogenic factors such as TNF-α, COX-2, and VEGF. Both corneal opacity and corneal neovascularization (CNV) were significantly decreased in the PEP-1-FK506BP treated group. Our results showed that PEP-1-FK506BP can significantly inhibit alkali burn-induced corneal inflammation in rats, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors and inflammatory cytokines. These results suggest that PEP-1-FK506BP may be a potential therapeutic agent for CAI. [BMB Reports 2015; 48(11): 618-623] 相似文献
7.
Granek Leeat Nakash Ora Ariad Samuel Shapira Shahar Ben-David Merav A. 《Culture, medicine and psychiatry》2020,44(2):214-229
Culture, Medicine, and Psychiatry - To explore the role of culture in communicating with cancer patients about mental health distress and suicidality. The Grounded Theory method of data collection... 相似文献
8.
9.
Jeff J. Stephenson Matt R. Campbell Jon E. Hess Chris Kozfkay Andrew P. Matala Megan V. McPhee Paul Moran Shawn R. Narum Melanie M. Paquin Ora Schlei Maureen P. Small Donald M. Van Doornik John K. Wenburg 《Conservation Genetics》2009,10(4):1145-1149
We demonstrate an efficient model for standardizing microsatellite DNA data among laboratories studying Oncorhynchus mykiss. Eight laboratories standardized 13 microsatellite loci following allele nomenclature of a central laboratory (average inter-laboratory
genotyping concordance >98%). Following this central model, we have currently standardized 298 alleles from throughout the
species native range. Although we focus here on O. mykiss, our experiences and recommendation apply equally to other broadly distributed species that may benefit from multi-laboratory
collaborative data collection. 相似文献
10.
Proteins are active, flexible machines that perform a range of different
functions. Innovative experimental approaches may now provide limited partial
information about conformational changes along motion pathways of proteins.
There is therefore a need for computational approaches that can efficiently
incorporate prior information into motion prediction schemes. In this paper, we
present PathRover, a general setup designed for the integration
of prior information into the motion planning algorithm of rapidly exploring
random trees (RRT). Each suggested motion pathway comprises a sequence of
low-energy clash-free conformations that satisfy an arbitrary number of prior
information constraints. These constraints can be derived from experimental data
or from expert intuition about the motion. The incorporation of prior
information is very straightforward and significantly narrows down the vast
search in the typically high-dimensional conformational space, leading to
dramatic reduction in running time. To allow the use of state-of-the-art energy
functions and conformational sampling, we have integrated this framework into
Rosetta, an accurate protocol for diverse types of structural modeling. The
suggested framework can serve as an effective complementary tool for molecular
dynamics, Normal Mode Analysis, and other prevalent techniques for predicting
motion in proteins. We applied our framework to three different model systems.
We show that a limited set of experimentally motivated constraints may
effectively bias the simulations toward diverse predicates in an outright
fashion, from distance constraints to enforcement of loop closure. In
particular, our analysis sheds light on mechanisms of protein domain swapping
and on the role of different residues in the motion. 相似文献