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1.
L S Zalman M A Brothers H J Müller-Eberhard 《Journal of immunology (Baltimore, Md. : 1950)》1989,143(6):1943-1947
A soluble form of homologous restriction factor (HRF-U) was isolated from normal human urine. With respect to m.w. (65,000) and immunoblotting characteristics, it resembled membrane HRF (HRF-M) that had been isolated from human E membranes. The protein exhibited limited cross-reactivity with the channel-forming proteins of C and cytotoxic lymphocytes. It inhibited reactive lysis of E by human C5b-9. Inhibition occurred at the attachment stage of C5b-7 to target cells, rather than at the C8 or C9 stage of membrane attack complex assembly which is inhibited by HRF-M. In this respect, HRF-U acts analogously to S protein of serum, but no immunochemical relationship between these two proteins was detected. HRF-U might be derived from the soluble HRF detected in cytoplasmic granules of killer lymphocytes. 相似文献
2.
Dominant cell death induction by extramitochondrially targeted apoptosis-inducing factor. 总被引:24,自引:0,他引:24
M Loeffler E Daugas S A Susin N Zamzami D Metivier A L Nieminen G Brothers J M Penninger G Kroemer 《FASEB journal》2001,15(3):758-767
The complete AIF cDNA comprising the amino-terminal mitochondrial localization sequence (MLS) and the oxidoreductase domain has been fused in its carboxyl terminus to enhanced green fluorescent protein (GFP), thereby engineering an AIF-GFP fusion protein that is selectively targeted to the mitochondrial intermembrane space. Upon induction of apoptosis, the AIF-GFP protein translocates together with cytochrome c (Cyt-c) to the extramitochondrial compartment. Microinjection of recombinant AIF leads to the release of AIF-GFP and Cyt-c-GFP, indicating that ectopic AIF can favor permeabilization of the outer mitochondrial membrane. These mitochondrial effects of AIF are caspase independent, whereas the Cyt-c-microinjection induced translocation of AIF-GFP and Cyt-c-GFP is suppressed by the pan-caspase inhibitor Z-VAD.fmk. Upon prolonged culture, transfection-enforced overexpression of AIF results in spontaneous translocation of AIF-GFP from mitochondria, nuclear chromatin condensation, and cell death. These effects are caspase independent and do not rely on the oxidoreductase function of AIF. Spontaneous AIF-GFP translocation and subsequent nuclear apoptosis can be retarded by overexpression of a Bcl-2 protein selectively targeted to mitochondria, but not by a Bcl-2 protein targeted to the endoplasmic reticulum. Overexpression of a mutant AIF protein in which the MLS has been deleted (AIF Delta 1-100) results in the primary cytosolic accumulation of AIF. AIF Delta 1-100-induced cell death is suppressed by neither Z-VAD.fmk or by Bcl-2. Thus, extramitochondrially targeted AIF is a dominant cell death inducer. 相似文献
3.
Josiah MC Heyman 《The journal of the Royal Anthropological Institute》2000,6(4):635-652
High-scale morality is the study of moral ideas and sentiments deployed in relations that encompass multiple, geographically or socially distant populaces. The envisioning of distant people, their attributed moral personhood, the evaluation of their perceived behaviour, and the rectification of wrongs through the use of powerful organizations are key topics in high-scale morality. High-scale morality differs from existing anthropological approaches that emphasize local ethnography or contrastive moral ideas; it addresses the moralization of issues like world hunger, the drug trade, or international migration. The officers of the US Immigration and Naturalization Service understand and evaluate legal and illegal immigrants, as well as directly enacting moral rectification for the US polity. As they resolve moral dilemmas on their job, they utilize pervasive models for moral thought and action in capitalist, individualist, stratified, and bureaucratized societies. The article finishes by considering directions in which anthropology can contribute to understanding the moral dimension of global issues. 相似文献
4.
Patrick LJM Zeeuwen Jos Boekhorst Ellen H van den Bogaard Heleen D de Koning Peter MC van de Kerkhof Delphine M Saulnier Iris I van Swam Sacha AFT van Hijum Michiel Kleerebezem Joost Schalkwijk Harro M Timmerman 《Genome biology》2012,13(11):R101
Background
Recent advances in sequencing technologies have enabled metagenomic analyses of many human body sites. Several studies have catalogued the composition of bacterial communities of the surface of human skin, mostly under static conditions in healthy volunteers. Skin injury will disturb the cutaneous homeostasis of the host tissue and its commensal microbiota, but the dynamics of this process have not been studied before. Here we analyzed the microbiota of the surface layer and the deeper layers of the stratum corneum of normal skin, and we investigated the dynamics of recolonization of skin microbiota following skin barrier disruption by tape stripping as a model of superficial injury.Results
We observed gender differences in microbiota composition and showed that bacteria are not uniformly distributed in the stratum corneum. Phylogenetic distance analysis was employed to follow microbiota development during recolonization of injured skin. Surprisingly, the developing neo-microbiome at day 14 was more similar to that of the deeper stratum corneum layers than to the initial surface microbiome. In addition, we also observed variation in the host response towards superficial injury as assessed by the induction of antimicrobial protein expression in epidermal keratinocytes.Conclusions
We suggest that the microbiome of the deeper layers, rather than that of the superficial skin layer, may be regarded as the host indigenous microbiome. Characterization of the skin microbiome under dynamic conditions, and the ensuing response of the microbial community and host tissue, will shed further light on the complex interaction between resident bacteria and epidermis. 相似文献5.
Ganio MS Brothers RM Lucas RA Hastings JL Crandall CG 《American journal of physiology. Regulatory, integrative and comparative physiology》2011,301(5):R1510-R1516
Despite frequent reporting of blood pressure (BP) during profound passive heat stress, both with and without a hypotensive challenge, the method by which BP is measured often varies between laboratories. It is unknown whether auscultatory and finger BP measures accurately reflect intra-arterial BP during dynamic changes in cardiac output and peripheral resistance associated with the aforementioned conditions. The purpose of this investigation was to test the hypothesis that auscultatory BP measured at the brachial artery, and finger BP measured by the Penaz method, are valid measures of intra-arterial BP during a passive heat stress and a heat-stressed orthostatic challenge, via lower body negative pressure (LBNP). Absolute (specific aim 1) and the change in (specific aim 2) systolic (SBP), diastolic (DBP), and mean BPs (MBP) were compared at normothermia, after a core temperature increase of 1.47 ± 0.09°C, and during subsequent LBNP. Heat stress did not change auscultatory SBP (6 ± 11 mmHg; P = 0.16), but Penaz SBP (-22 ± 16 mmHg; P < 0.001) and intra-arterial SBP (-11 ± 13 mmHg P = 0.017) decreased. In contrast, DBP and MBP did not differ between methods throughout heat stress. Compared with BP before LBNP, the magnitude of the reduction in BP with all three methods was similar throughout LBNP (P > 0.05). In conclusion, auscultatory SBP and Penaz SBP failed to track the decrease in intra-arterial SBP that occurred during the profound heat stress, while decreases in arterial BP during an orthostatic challenge are comparable between methodologies. 相似文献
6.
Hypothetically, a species with both cleistogamous (CL) flowers and delayed selfing chasmogamous (CH) flowers should display high levels of reproductive assurance because, over time, obligate selfing by CL flowers should reduce inbreeding depression and delayed selfing in CH flowers should compensate for the absence of outcross pollen. We used pollinator-exclusion experiments to investigate reproductive assurance in the CH flowers of Polygala lewtonii, an herb with a mixed mating system. We followed CH flowers from bud-break to flower/fruit abscission to quantify fruit initiation and maturation and rates of floral development. We also evaluated the efficacy of the selfing mechanism, conducted pollinator watches to assess the likelihood of pollinator limitation, and performed regression analysis to determine the effect of flower position on fruit production. Pollinator exclusion significantly reduced fruit initiation and maturation. Investigation of floral development demonstrated that the selfing mechanism is largely dysfunctional in CH flowers, indicating the failure of reproductive assurance. Low observed rates of insect visitation appear to contradict high rates of CH fruit production in open-pollinated plants, particularly given the rarity of delayed selfing. In both treatments, flower position significantly affected fruit initiation, suggesting a role for resource limitation in both pollinator-excluded and open-pollinated flowers. 相似文献
7.
8.
Hundreds of thousands of seabirds are killed each year as bycatch in longline fisheries. Seabirds are predominantly caught during line setting but bycatch is generally recorded during line hauling, many hours after birds are caught. Bird loss during this interval may lead to inaccurate bycatch information. In this 15 year study, seabird bycatch was recorded during both line setting and line hauling from four fishing regions: Indian Ocean, Southern Ocean, Coral Sea and central Pacific Ocean. Over 43,000 albatrosses, petrels and skuas representing over 25 species were counted during line setting of which almost 6,000 seabirds attempted to take the bait. Bait-taking interactions were placed into one of four categories. (i) The majority (57%) of bait-taking attempts were “unsuccessful” involving seabirds that did not take the bait nor get caught or hooked. (ii) One-third of attempts were “successful” with seabirds removing the bait while not getting caught. (iii) One-hundred and seventy-six seabirds (3% of attempts) were observed being “caught” during line setting, with three albatross species – Laysan (Phoebastria immutabilis), black-footed (P. nigripes) and black-browed (Thalassarche melanophrys)– dominating this category. However, of these, only 85 (48%) seabird carcasses were retrieved during line hauling. Most caught seabirds were hooked through the bill. (iv) The remainder of seabird-bait interactions (7%) was not clearly observed, but likely involved more “caught” seabirds. Bait taking attempts and percentage outcome (e.g. successful, caught) varied between seabird species and was not always related to species abundance around fishing vessels. Using only haul data to calculate seabird bycatch grossly underestimates actual bycatch levels, with the level of seabird bycatch from pelagic longline fishing possibly double what was previously thought. 相似文献
9.
van Beers JJ Raijmakers R Alexander LE Stammen-Vogelzangs J Lokate AM Heck AJ Schasfoort RB Pruijn GJ 《Arthritis research & therapy》2010,12(6):R219
Introduction
Rheumatoid arthritis (RA) frequently involves the loss of tolerance to citrullinated antigens, which may play a role in pathogenicity. Citrullinated fibrinogen is commonly found in inflamed synovial tissue and is a frequent target of autoantibodies in RA patients. To obtain insight into the B-cell response to citrullinated fibrinogen in RA, its autoepitopes were systematically mapped using a new methodology. 相似文献10.
R. Cronn M. Brothers K. Klier P. K. Bretting J. F. Wendel 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(4):532-545
The annual sunflower (Helianthus annuus L.) is a morphologically and genetically variable species composed of wild, weedy, and domesticated forms that are used for
ornament, oilseed, and edible seeds. In this study, we evaluated genetic variation in 146 germplasm accessions of wild and
domesticated sunflowers using allozyme analysis. Results from this survey showed that wild sunflower exhibits geographically
structured genetic variation, as samples from the Great Plains region of the central United States were genetically divergent
from accessions from California and the southwestern United States. Sunflower populations from the Great Plains harbored greater
allelic diversity than did wild sunflower from the western United States. Comparison of genetic variability in wild and domesticated
sunflower by principal coordinate analysis showed these groups to be genetically divergent, in large part due to differences
in the frequency of common alleles. Neighbor-Joining analyses of domesticated H. annuus, wild H. annuus and two closely related wild species (H. argophyllus T. & G. and H. petiolaris Nutt.) showed that domesticated sunflowers form a genetically coherent group and that wild sunflowers from the Great Plains
may include the most likely progenitor of domesticated sunflowers.
Received: 2 December 1996/Accepted: 4 April 1997 相似文献