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71.
72.
Gerald D. Fasman 《Journal of biosciences》1985,8(1-2):15-23
The Chou-Fasman predictive algorithm for determining the secondary structure of proteins from the primary sequence is reviewed.
Many examples of its use are presented which illustrate its wide applicability, such as predicting (a) regions with the potential
for conformational change, (b) sequences which are capable of assuming several conformations in different environments, (c)
effects of single amino acid mutations, (d) amino acid replacements in synthesis of peptides to bring about a change in conformation,
(e) guide to the synthesis of polypeptides with definitive secondary structure,e.g. signal sequences, (f) conformational homologues from varying sequences and (g) the amino acid requirements for amphiphilicα-helical peptides. 相似文献
73.
Aketarawong N Chinvinijkul S Orankanok W Guglielmino CR Franz G Malacrida AR Thanaphum S 《Genetica》2011,139(1):129-140
The oriental fruit fly, Bactrocera dorsalis (Hendel), is a key pest that causes reduction of the crop yield within the international fruit market. Fruit flies have been
suppressed by two Area-Wide Integrated Pest Management programs in Thailand using Sterile Insect Technique (AW-IPM-SIT) since
the late 1980s and the early 2000s. The projects’ planning and evaluation usually rely on information from pest status, distribution,
and fruit infestation. However, the collected data sometimes does not provide enough detail to answer management queries and
public concerns, such as the long term sterilization efficacy of the released fruit fly, skepticism about insect migration
or gene flow across the buffer zone, and the re-colonisation possibility of the fruit fly population within the core area.
Established microsatellite DNA markers were used to generate population genetic data for the analysis of the fruit fly sampling
from several control areas, and non-target areas, as well as the mass-rearing facility. The results suggested limited gene
flow (m < 0.100) across the buffer zones between the flies in the control areas and flies captured outside. In addition, no genetic
admixture was revealed from the mass-reared colony flies from the flies within the control area, which supports the effectiveness
of SIT. The control pests were suppressed to low density and showed weak bottleneck footprints although they still acquired
a high degree of genetic variation. Potential pest resurgence from fragmented micro-habitats in mixed fruit orchards rather
than pest incursion across the buffer zone has been proposed. Therefore, a suitable pest control effort, such as the SIT program,
should concentrate on the hidden refuges within the target area. 相似文献
74.
75.
Somatic embryogenesis (SE) is expected to play an important role in increasing productivity, sustainability, and uniformity
of future US forests. For commercial use, SE technology must work with a variety of genetically diverse trees. Initiation
in loblolly pine (Pinus taeda L.), the main commercial US forest species, is often recalcitrant for desirable genotypes. Liquid initiation medium with
no or low gelling agent or placement of the explant on gelled medium followed later by a liquid medium overlay during the
initiation process increased initiation for loblolly pine and Norway spruce (Picea abies). Loblolly pine liquid medium required reduction of NAA from 2 mg/l in gelled medium to 0.3 mg/l in liquid medium. Once the
NAA concentration was adjusted, loblolly pine initiation occurred in liquid medium with fully immersed megagametophytes, explants
supported at the liquid medium surface, or on gelled medium overlaid with liquid medium. Liquid overlays (0.25 ml) consisting
of medium with NAA reduced to 0.3 mg/l, 9 mg/l ABA and no gelling agent applied to explants on 2 ml of gelled medium provided
excellent initiation results. Greatest initiation percentages occurred when the liquid overlay was applied 14 days after placement
of the megagametophyte on gelled medium. Initiation increases ranged from +8.5% with high-value cross-pollinated seed sources
to +6.5 to +9.9% with open-pollinated and often recalcitrant seed sources. Liquid medium addition allows rapid replenishment
of nutrients and adjustment or change of pH, hormones, or other parameters without disturbing the tissue. 相似文献
76.
Loss of Kindlin-1 Causes Skin Atrophy and Lethal Neonatal Intestinal Epithelial Dysfunction 下载免费PDF全文
Siegfried Ussar Markus Moser Moritz Widmaier Emanuel Rognoni Christian Harrer Orsolya Genzel-Boroviczeny Reinhard F?ssler 《PLoS genetics》2008,4(12)
Kindler Syndrome (KS), characterized by transient skin blistering followed by abnormal pigmentation, skin atrophy, and skin cancer, is caused by mutations in the FERMT1 gene. Although a few KS patients have been reported to also develop ulcerative colitis (UC), a causal link to the FERMT1 gene mutation is unknown. The FERMT1 gene product belongs to a family of focal adhesion proteins (Kindlin-1, -2, -3) that bind several β integrin cytoplasmic domains. Here, we show that deleting Kindlin-1 in mice gives rise to skin atrophy and an intestinal epithelial dysfunction with similarities to human UC. This intestinal dysfunction results in perinatal lethality and is triggered by defective intestinal epithelial cell integrin activation, leading to detachment of this barrier followed by a destructive inflammatory response. 相似文献
77.
Jakob Vinther Derek E. G. Briggs Julia Clarke Gerald Mayr Richard O. Prum 《Biology letters》2010,6(1):128-131
Investigation of feathers from the famous Middle Eocene Messel Oil Shale near Darmstadt, Germany shows that they are preserved as arrays of fossilized melanosomes, the surrounding beta-keratin having degraded. The majority of feathers are preserved as aligned rod-shaped eumelanosomes. In some, however, the barbules of the open pennaceous, distal portion of the feather vane are preserved as a continuous external layer of closely packed melanosomes enclosing loosely aligned melanosomes. This arrangement is similar to the single thin-film nanostructure that generates an iridescent, structurally coloured sheen on the surface of black feathers in many lineages of living birds. This is, to our knowledge, the first evidence of preservation of a colour-producing nanostructure in a fossil feather and confirms the potential for determining colour differences in ancient birds and other dinosaurs. 相似文献
78.
Gerald Brandacher Johanna Grahammer Robert Sucher Wei‐Ping Andrew Lee 《Birth defects research. Part C, Embryo today : reviews》2012,96(1):39-50
Reconstructive transplantation represents a bona fide option for select patients with devastating tissue loss, which could better restore the appearance, anatomy, and function than any other conventional treatment currently available. Despite favorable outcomes, broad clinical application of reconstructive transplantation is limited by the potential side effects of chronic multidrug immunosuppression. Thus, any reconstructive measures to improve these non‐life‐threatening conditions must address a delicate balance of risks and benefits. Today, several exciting novel therapeutic strategies, such as the implementation of cellular therapies including bone marrow or stem cells that integrate the concepts of immune regulation with those of nerve regeneration, are on the horizon. The development of reliable and reproducible small andlarge animal models is essential for the study of the unique immunological and biological aspects of vascularized composite allografts and to translate such novel immunoregulatory and tolerance‐inducing strategies and therapeutic concepts from the bench to bedside. This review provides an overview of the multitude of small and largeanimal models that have been particularly designed for basicand translational research related to reconstructive transplantation. (Part C) 96:39–50, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
79.
Question: Does the upward shift of species and accompanied increase in species richness, induced by climate change, lead to homogenization of Alpine summit vegetation? Location: Bernina region of the Swiss Alps. Methods: Based on a data set from previous literature we expand the analysis from species richness to beta‐diversity and spatial heterogeneity. Species compositions of mountain summits are compared using a two‐component heterogeneity concept including the mean and the variance of Sørensen similarities calculated between the summits. Non‐metric multidimensional scaling is applied to explore developments of single summits in detail. Results: Both heterogeneity components (mean dissimilarity and variance) decrease over time, indicating a trend towards more homogeneous vegetation among Alpine summits. However, the development on single summits is not strictly unidirectional. Conclusions: The upward shift of plant species leads to homogenization of alpine summit regions. Thus, increasing alpha‐diversity is accompanied by decreasing beta‐diversity. Beta‐diversity demands higher recognition by scientists as well as nature conservationists as it detects changes which cannot be described using species richness alone. 相似文献
80.
Bo Zhang Phillip E. Wilson Gerald D. Watt 《Journal of biological inorganic chemistry》2006,11(8):1075-1086
Ferritin catalyzes the oxidation of Fe2+ by O2 to form a reconstituted Fe3+ oxy-hydroxide mineral core, but extensive studies have shown that the Fe2+ to O2 stoichiometry changes with experimental conditions. At Fe2+ to horse spleen ferritin (HoSF) ratios greater than 200, an upper limit of Fe2+ to O2 of 4 is typically measured, indicating O2 is reduced to 2H2O. In contrast, a lower limit of Fe2+ to O2 of approximately 2 is measured at low Fe2+ to HoSF ratios, implicating H2O2 as a product of Fe2+ deposition. Stoichiometric amounts of H2O2 have not been measured, and H2O2 is proposed to react with an unknown system component. Evidence is presented that identifies this component as amine buffers, including 3-N-morpholinopropanesulfonic acid (MOPS), which is widely used in ferritin studies. In the presence of non-amine buffers, the Fe2+ to O2 stoichiometry was approximately 4.0, but at high concentrations of amine buffers (0.10 M) the Fe2+ to O2 stoichiometry is approximately 2.5 for iron loadings of eight to 30 Fe2+ per HoSF. Decreasing the concentration of amine buffer to zero resulted in an Fe2+ to O2 stoichiometry of approximately 4. Direct evidence for amine buffer modification during Fe2+ deposition was obtained by comparing authentic and modified buffers using mass spectrometry, NMR, and thin layer chromatography. Tris(hydroxymethyl)aminomethane, MOPS, and N-methylmorpholine (a MOPS analog) were all rapidly chemically modified during Fe2+ deposition to form N-oxides. Under identical conditions no modification was detected when amine buffer, H2O2, and O2 were combined with Fe2+ or ferritin separately. Thus, a short-lived ferritin intermediate is required for buffer modification by H2O2. Variation of the Fe2+ to O2 stoichiometry versus the Fe2+ to HoSF ratio and the amine buffer concentration are consistent with buffer modification. 相似文献