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991.
Bahassi el M Penner CG Robbins SB Tichy E Feliciano E Yin M Liang L Deng L Tischfield JA Stambrook PJ 《Mutation research》2007,616(1-2):201-209
Allelic variants of CHEK2 contribute to an elevated risk for human breast cancer and possibly other cancer types. In particular, the CHEK2*1100delC polymorphic variant has been identified as a low-penetrance breast cancer susceptibility allele in breast cancer families with wild type BRCA1 and BRCA2. To better understand the molecular basis by which this allele increases risk for disease, we have generated a mouse in which the wild type CHEK2 (Chk2 in mouse) allele has been replaced with the 1100delC variant. Mouse embryo fibroblasts (MEFs) derived from these mice have an altered cell cycle profile in which a far greater proportion of cells are in S-phase and in G2 (4N) compared with wild type cells. The mutant cells show signs of spontaneous genomic instability as indicated by polyploidy and an increase in DNA double strand breaks. 相似文献
992.
Optimizing protein intake as a foraging strategy to maximize mass gain in an omnivore 总被引:2,自引:0,他引:2
Charles T. Robbins Jennifer K. Fortin Karyn D. Rode Sean D. Farley Lisa A. Shipley Laura A. Felicetti 《Oikos》2007,116(10):1675-1682
Energy maximization, time minimization, and linear programming models subject to various constraints have dominated foraging ecology ideas and methods for decades. However, animals must use very complex physiological processes and foraging decisions to ensure fitness that in many cases may not be adequately described by these approaches. An example of this problem occurs when brown bears, Ursus arctos, have access to both abundant salmon and fruit. Salmon are one of the most energy and nutrient dense foods available to bears. Fruits are often high in soluble carbohydrates, low to deficient in many required nutrients, and more difficult to efficiently exploit. Therefore, wild brown bears that fatten primarily on fruits without access to salmon are 50% smaller than salmon-feeding bears. Thus, we predicted based on a linear, energy-maximizing model without dietary interaction effects that wild brown bears with access to both abundant salmon and fruit would feed almost exclusively on salmon. However, wild adult females with or without accompanying offspring foraged three times longer per day on fruit than on salmon. Similarly, the relative dry matter intake of ad libitum apples and salmon by captive, adult brown bears averaged 76±5% fruit and 24±5% salmon. Captive brown bears consuming mixed diets with intermediate dietary protein levels had 60% lower maintenance energy costs, 37% to 139% higher efficiencies of mass gain, and 72% to 520% higher maximum rates of gain than when they consumed either salmon or fruit alone. These relationships were nonlinear functions of dietary protein content in which salmon and fruit provided complementary nutritional resources. Both wild and captive bears attempted to regulate total protein, energy, and carbohydrate intake within a multidimensional intake target that both maximized energy intake and mass gain. 相似文献
993.
Stieber V Robbins M Balamucki C deGuzman A Tatter S Ekstrand K McMullen K Branch C Shaw E Bourland JD Lovato J Munley M Ellis T 《Radiation research》2007,168(2):143-148
Stereotactic radiosurgery (GKRS) using the Leksell Gamma Knife is a treatment option for patients with trigeminal pain. We analyzed a database of 326 GKRS procedures performed over 4.6 years at three discrete dose levels commonly described in the published literature. Logistic regression was used to model the logit of response as a function of treatment time. The resulting coefficient was converted to an estimated probability of response for the shortest and longest treatment times in clinical practice. The two estimated probabilities were then compared to yield the estimated difference in the biologically effective dose (BED) between the two doses, using a modified linear-quadratic model for stereotactic radiosurgery. This difference was used to back-calculate a clinical value for T(1/2), resulting in a range of 1.28-1.77 h for T(1/2). The biological model appeared to accurately predict that, given the doses and treatment times used in general clinical practice, there would be no significant difference in clinical outcome. 相似文献
994.
Hydrobiologia - Beaked whales are cryptic and difficult to study species, often distributed in deep offshore waters and only briefly visible at the surface. A diverse range of cetacean species has... 相似文献
995.
996.
Energetic responses to variation in food availability in the two mountain gorilla populations (Gorilla beringei beringei) 下载免费PDF全文
997.
Maeve O’Leary-Barrett Robert O. Pihl Eric Artiges Tobias Banaschewski Arun L. W. Bokde Christian Büchel Herta Flor Vincent Frouin Hugh Garavan Andreas Heinz Bernd Ittermann Karl Mann Marie-Laure Paillère-Martinot Frauke Nees Tomas Paus Zdenka Pausova Luise Poustka Marcella Rietschel Trevor W. Robbins Michael N. Smolka Andreas Str?hle Gunter Schumann Patricia J. Conrod IMAGEN Consortium 《PloS one》2015,10(6)
Objective
To investigate the role of personality factors and attentional biases towards emotional faces, in establishing concurrent and prospective risk for mental disorder diagnosis in adolescence.Method
Data were obtained as part of the IMAGEN study, conducted across 8 European sites, with a community sample of 2257 adolescents. At 14 years, participants completed an emotional variant of the dot-probe task, as well two personality measures, namely the Substance Use Risk Profile Scale and the revised NEO Personality Inventory. At 14 and 16 years, participants and their parents were interviewed to determine symptoms of mental disorders.Results
Personality traits were general and specific risk indicators for mental disorders at 14 years. Increased specificity was obtained when investigating the likelihood of mental disorders over a 2-year period, with the Substance Use Risk Profile Scale showing incremental validity over the NEO Personality Inventory. Attentional biases to emotional faces did not characterise or predict mental disorders examined in the current sample.Discussion
Personality traits can indicate concurrent and prospective risk for mental disorders in a community youth sample, and identify at-risk youth beyond the impact of baseline symptoms. This study does not support the hypothesis that attentional biases mediate the relationship between personality and psychopathology in a community sample. Task and sample characteristics that contribute to differing results among studies are discussed. 相似文献998.
Are residents of mountain‐top mining counties more likely to have infants with birth defects? The west virginia experience 下载免费PDF全文
999.
Factors associated with inpatient hospitalizations among patients aged 1 to 64 years with Congenital heart defects,Arkansas 2006 to 2011 下载免费PDF全文
1000.
Weigle DS Buben A Burke CC Carroll ND Cook BM Davis BS Dubowitz G Fisher RE Freeman TC Gibbons SM Hansen HA Heys KA Hopkins B Jordan BL McElwain KL Powell FL Reinhart KE Robbins CD Summers CC Walker JD Weber SS Weinheimer CJ 《Advances in physiology education》2007,31(3):270-278
In this article, an experiential learning activity is described in which 19 university undergraduates made experimental observations on each other to explore physiological adaptations to high altitude. Following 2 wk of didactic sessions and baseline data collection at sea level, the group ascended to a research station at 12,500-ft elevation. Here, teams of three to four students measured the maximal rate of oxygen uptake, cognitive function, hand and foot volume changes, reticulocyte count and hematocrit, urinary pH and 24-h urine volume, athletic performance, and nocturnal blood oxygen saturation. Their data allowed the students to quantify the effect of altitude on the oxygen cascade and to demonstrate the following altitude-related changes: 1) impaired performance on selected cognitive function tests, 2) mild peripheral edema, 3) rapid reticulocytosis, 4) urinary alkalinization and diuresis, 5) impaired aerobic but not anaerobic exercise performance, 6) inverse relationship between blood oxygen saturation and resting heart rate, and 7) regular periodic nocturnal oxygen desaturation events accompanied by heart rate accelerations. The students learned and applied basic statistical techniques to analyze their data, and each team summarized its results in the format of a scientific paper. The students were uniformly enthusiastic about the use of self-directed experimentation to explore the physiology of altitude adaptation and felt that they learned more from this course format than a control group of students felt that they learned from a physiology course taught by the same instructor in the standard classroom/laboratory format. 相似文献