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151.
An enzyme-linked immunosorbent assay (ELISA) for the Alternaria mycotoxin tenuazonic acid (TeA) was evaluated by comparative analysis of naturally contaminated sorghum grains and sorghum-based infant food, using a stable isotope dilution LC-MS assay (SIDA; limit of detection (LOD) 1.0 μg/kg) as the reference method. LODs of the ELISA were 30 μg/kg in sorghum grains and 220 μg/kg in sorghum-based infant cereals. With SIDA, 100% of the samples (n = 28) had been positive for TeA in a concentration range of 6–584 μg/kg (mean 113 μg/kg). The ELISA consistently detected TeA in all naturally contaminated samples at cut-off levels of 30–60 μg/kg (sorghum) and 200–300 μg/kg (infant cereals), as based on corresponding to SIDA values. Although the ELISA was much less sensitive than the SIDA method, it may be useful as a screening method for sorghum and sorghum-based infant foods and can be employed to identify samples containing elevated concentrations of TeA in food, well below the proposed level of concern (500 μg/kg). 相似文献
152.
Foraging in honeybees--when does it pay to dance? 总被引:1,自引:0,他引:1
Honeybees are unique in that they are the only social insectsthat are known to recruit nest mates using the waggle dance.This waggle dance is used by successful foragers to convey informationabout both the direction and distance to food sources. Nestmates can use this spatial information, increasing their chancesof locating the food source. But how effective is the bees'dance communication? Previous work has shown that dancing doesnot benefit a honeybee colony under all foraging conditionsand that the benefits of dancing are small. We used an individual-basedsimulation model to investigate under which foraging conditionsit pays to dance. We compared the net nectar intake of 3 typesof colonies: 1) colonies that use dance communication; 2) coloniesthat did dance but could not use the dance's spatial information;and 3) colonies that did not dance. Our results show that dancingis beneficial when the probability of independent discoveryof food sources is low. Low independent discovery rates occurwhen patches are very small or very far away. Under these conditions,dancing is beneficial as only a single individual needs to finda patch for the whole colony to benefit. The main benefit ofthe honeybee's dance communication, however, seems to be thatit enables the colony to forage at the most profitable patchesonly, ignoring forage patches that are of low quality. Thus,dancing allows the colony to rapidly exploit high-quality patches,thereby preventing both intra- and interspecific competitorsfrom using that same patch. 相似文献
153.
Andrews DM Stokes ES Carr GR Matusiak ZS Roberts CA Waring MJ Brady MC Chresta CM East SJ 《Bioorganic & medicinal chemistry letters》2008,18(8):2580-2584
A lead benzamide, 3, was identified as a potent and low molecular weight histone deacetylase (HDAC) inhibitor. Optimization led to 16d, demonstrating an excellent balance of efficacy and non-efficacy properties, along with very desirable in vivo DMPK. The final compounds presented are >1000-fold more potent than the initial screen hit, an improvement in potency which was achieved with a concomitant significant improvement in all the main non-efficacy properties. 相似文献
154.
Serge A. Wich Karyl B. Swartz Madeleine E. Hardus Adriano R. Lameira Erin Stromberg Robert W. Shumaker 《Primates; journal of primatology》2009,50(1):56-64
The capacity of nonhuman primates to actively modify the acoustic structure of existing sounds or vocalizations in their repertoire
appears limited. Several studies have reported population or community differences in the acoustical structure of nonhuman
primate long distance calls and have suggested vocal learning as a mechanism for explaining such variation. In addition, recent
studies on great apes have indicated that there are repertoire differences between populations. Some populations have sounds
in their repertoire that others have not. These differences have also been suggested to be the result of vocal learning. On
yet another level great apes can, after extensive human training, also learn some species atypical vocalizations. Here we
show a new aspect of great ape vocal learning by providing data that an orangutan has spontaneously (without any training)
acquired a human whistle and can modulate the duration and number of whistles to copy a human model. This might indicate that
the learning capacities of great apes in the auditory domain might be more flexible than hitherto assumed.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
155.
Ira R. Kim Kiichi Murakami Nien-Jung Chen Samuel D. Saibil Elzbieta Matysiak-Zablocki Alisha R. Elford Madeleine Bonnard Samuel Benchimol Andrea Jurisicova Wen-Chen Yeh Pamela S. Ohashi 《Apoptosis : an international journal on programmed cell death》2009,14(9):1039-1049
The p53-induced protein with a death domain, PIDD, was identified as a p53 target gene whose main role is to execute apoptosis
in a p53-dependent manner. To investigate the physiological role of PIDD in apoptosis, we generated PIDD-deficient mice. Here,
we report that, although PIDD expression is inducible upon DNA damage, PIDD-deficient mice undergo apoptosis normally not
only in response to DNA damage, but also in response to various p53-independent stress signals and to death receptor (DR)
engagement. This indicates that PIDD is not required for DNA damage-, stress-, and DR-induced apoptosis. Also, in the absence
of PIDD, both caspase-2 processing and activation occur in response to DNA damage. Our findings demonstrate that PIDD does
not play an essential role for all p53-mediated or p53-independent apoptotic pathways.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
156.
157.
Anecdotal, Historical and Critical Commentaries on Genetics: The Szilard Hypothesis on the Nature of Aging Revisited
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Henrik Zetterberg Magnus Bth Madeleine Zetterberg Peter Bernhardt Ola Hammarsten 《Genetics》2009,182(1):3-9
This year marks the 50th anniversary of a nearly forgotten hypothesis on aging by Leo Szilard, best known for his pioneering work in nuclear physics, his participation in the Manhattan Project during World War II, his opposition to the nuclear arms race in the postwar era, and his pioneering ideas in biology. Given a specific set of assumptions, Szilard hypothesized that the major reason for the phenomenon of aging was aging hits, e.g., by ionizing radiation, to the gene-bearing chromosomes and presented a mathematical target-hit model enabling the calculation of the average and maximum life span of a species, as well as the influence of increased exposure to DNA-damaging factors on life expectancy. While many new findings have cast doubt on the specific features of the model, this was the first serious effort to posit accumulated genetic damage as a cause of senescence. Here, we review Szilard's assumptions in the light of current knowledge on aging and reassess his mathematical model in an attempt to reach a conclusion on the relevance of Szilard's aging hypothesis today. 相似文献
158.
159.
Grit Nebrich Marion Herrmann Daniela Hartl Madeleine Diedrich Thomas Kreitler Christoph Wierling Joachim Klose Patrick Giavalisco Claus Zabel Dr. Lei Mao 《Proteomics》2009,9(7):1795-1808
In recent years proteomics became increasingly important to functional genomics. Although a large amount of data is generated by high throughput large‐scale techniques, a connection of these mostly heterogeneous data from different analytical platforms and of different experiments is limited. Data mining procedures and algorithms are often insufficient to extract meaningful results from large datasets and therefore limit the exploitation of the generated biological information. In our proteomic core facility, which almost exclusively focuses on 2‐DE/MS‐based proteomics, we developed a proteomic database custom tailored to our needs aiming at connecting MS protein identification information to 2‐DE derived protein expression profiles. The tools developed should not only enable an automatic evaluation of single experiments, but also link multiple 2‐DE experiments with MS‐data on different levels and thereby helping to create a comprehensive network of our proteomics data. Therefore the key feature of our “PROTEOMER” database is its high cross‐referencing capacity, enabling integration of a wide range of experimental data. To illustrate the workflow and utility of the system, two practical examples are provided to demonstrate that proper data cross‐referencing can transform information into biological knowledge. 相似文献
160.
Krishna Jafa Peter McElroy Lisa Fitzpatrick Craig B. Borkowf Robin MacGowan Andrew Margolis Ken Robbins Ae Saekhou Youngpairoj Dale Stratford Alan Greenberg Jennifer Taussig R. Luke Shouse Madeleine LaMarre Eleanor McLellan-Lemal Walid Heneine Patrick S. Sullivan 《PloS one》2009,4(5)