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排序方式: 共有113条查询结果,搜索用时 14 毫秒
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Spring arrival response to climate change in birds: a case study from eastern Europe 总被引:3,自引:3,他引:0
Mecislovas Zalakevicius Galina Bartkeviciene Liutauras Raudonikis Justinas Janulaitis 《Journal of Ornithology》2006,147(2):326-343
This paper analyses the dependence of the first spring arrival dates of short/medium- and long-distance migrant bird species
on climate warming in eastern Europe. The timing of arrival of the selected species at the observation site correlates with
the North Atlantic Oscillation (NAO) index, air temperature, atmospheric pressure, precipitation and wind characteristics.
A positive correlation of fluctuations in winter and spring air temperatures with variations in the NAO index has been established
in eastern Europe. Positive winter NAO index values are related to earlier spring arrival of birds in the eastern Baltic region
and vice versa—arrival is late when the NAO index is negative. The impact of climate warming on the bird’s life cycle depends
on local or regional climate characteristics. We tested the hypothesis that differences in climate indices between North Africa
and Europe can influence the timing of spring arrival. Our results support the hypothesis that differences in first spring
arrival dates between European populations occur after individuals cross the Sahara. We assume that the endogenous programme
of migration control in short/medium-distance migrants synchronises with the changing environment on their wintering grounds
and along their migration routes, whereas in long-distance migrants it is rather with environmental changes in the second
part of their migratory route in Europe. Our results strongly indicate that the mechanism of dynamic balance in the interaction
between the endogenous regulatory programme and environmental factors determines the pattern of spring arrival, as well as
migration timing. 相似文献
14.
FspAI, a unique type II restriction endonuclease that recognizes the octanucleotide sequence 5′-RTGC↓GCAY-3′ 下载免费PDF全文
A. Kesminiene Z. Maneliene J. Vitkute M. Petruyte A. Janulaitis 《Nucleic acids research》2001,29(24):e120
A new type II restriction endonuclease designated FspAI has been partially purified from a Flexibacter species Tv-m21K. FspAI recognizes the octanucleotide sequence 5′-RTGC↓GCAY-3′ and cleaves it in the center generating blunt-ended DNA fragments. 相似文献
15.
Helen Louise May-Simera Qin Wan Balendu Shekhar Jha Juliet Hartford Vladimir Khristov Roba Dejene Justin Chang Sarita Patnaik Quanlong Lu Poulomi Banerjee Jason Silver Christine Insinna-Kettenhofen Dishita Patel Mostafa Lotfi May Malicdan Nathan Hotaling Arvydas Maminishkis Rupa Sridharan Kapil Bharti 《Cell reports》2018,22(1):189-205
16.
AbeI, a restriction endonuclease from Azotobacter beijerinckii, which recognizes the asymmetric heptanucleotide sequence 5'-CCTCAGC-3'(-5/-2). 下载免费PDF全文
A new restriction endonuclease Abe I has beenisolated from Azotobacter beijerinckii. This enzymerecognizes the asymmetric heptanucleotide sequence 5'-CCTCAGC-3' and cleaves within it symmetrically at positions -5/-2 in the opposing strands, producing three base protruding 5'-ends. 相似文献
17.
Crystal structure of MunI restriction endonuclease in complex with cognate DNA at 1.7 A resolution. 下载免费PDF全文
The MunI restriction enzyme recognizes the palindromic hexanucleotide sequence C/AATTG (the '/' indicates the cleavage site). The crystal structure of its active site mutant D83A bound to cognate DNA has been determined at 1.7 A resolution. Base-specific contacts between MunI and DNA occur exclusively in the major groove. While DNA-binding sites of most other restriction enzymes are comprised of discontinuous sequence segments, MunI combines all residues involved in the base-specific contacts within one short stretch (residues R115-R121) located at the N-terminal region of the 3(10)4 helix. The outer CG base pair of the recognition sequence is recognized solely by R115 through hydrogen bonds made by backbone and side chain atoms to both bases. The mechanism of recognition of the central AATT nucleotides by MunI is similar to that of EcoRI, which recognizes the G/AATTC sequence. The local conformation of AATT deviates from the typical B-DNA form and is remarkably similar to EcoRI-DNA. It appears to be essential for specific hydrogen bonding and recognition by MunI and EcoRI. 相似文献
18.
We have developed a cell culture procedure that can produce large quantities of confluent monolayers of primary human fetal retinal pigment epithelium (hfRPE) cultures with morphological, physiological and genetic characteristics of native human RPE. These hfRPE cell cultures exhibit heavy pigmentation, and electron microscopy show extensive apical membrane microvilli. The junctional complexes were identified with immunofluorescence labeling of various tight junction proteins. Epithelial polarity and function of these easily reproducible primary cultures closely resemble previously studied mammalian models of native RPE, including human. These results were extended by the development of therapeutic interventions in several animal models of human eye disease. We have focused on strategies for the removal of abnormal fluid accumulation in the retina or subretinal space. The extracellular subretinal space separates the photoreceptor outer segments and the apical membrane of the RPE and is critical for maintenance of retinal attachments and a whole host of RPE/retina interactions. 相似文献
19.
Oh HM Yu CR Lee Y Chan CC Maminishkis A Egwuagu CE 《Journal of immunology (Baltimore, Md. : 1950)》2011,187(6):3338-3346
Organ-specific autoimmune diseases are usually characterized by repeated cycles of remission and recurrent inflammation. However, where the autoreactive memory T cells reside in between episodes of recurrent inflammation is largely unknown. In this study, we have established a mouse model of chronic uveitis characterized by progressive photoreceptor cell loss, retinal degeneration, focal retinitis, retinal vasculitis, multifocal choroiditis, and choroidal neovascularization, providing for the first time to our knowledge a useful model for studying long-term pathological consequences of chronic inflammation of the neuroretina. We show that several months after inception of acute uveitis, autoreactive memory T cells specific to retinal autoantigen, interphotoreceptor retinoid-binding protein (IRBP), relocated to bone marrow (BM). The IRBP-specific memory T cells (IL-7Rα(High)Ly6C(High)CD4(+)) resided in BM in resting state but upon restimulation converted to IL-17/IFN-γ-expressing effectors (IL-7Rα(Low)Ly6C(Low)CD4(+)) that mediated uveitis. We further show that T cells from STAT3-deficient (CD4-STAT3KO) mice are defective in α4β1 and osteopontin expression, defects that correlated with inability of IRBP-specific memory CD4-STAT3KO T cells to traffic into BM. We adoptively transferred uveitis to naive mice using BM cells from wild-type mice with chronic uveitis but not BM cells from CD4-STAT3KO, providing direct evidence that memory T cells that mediate uveitis reside in BM and that STAT3-dependent mechanism may be required for migration into and retention of memory T cells in BM. Identifying BM as a survival niche for T cells that cause uveitis suggests that BM stromal cells that provide survival signals to autoreactive memory T cells and STAT3-dependent mechanisms that mediate their relocation into BM are attractive therapeutic targets that can be exploited to selectively deplete memory T cells that drive chronic inflammation. 相似文献
20.
V. Butkus J. Bitinait D. Kerulyt A. Janulaitis 《Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression》1985,826(4)
A restriction endonuclease with a novel site-specificity has been isolated from the Escherichia coli strain RFL31. The nucleotide sequences around a single Eco31I cut on pBR322 DNA and two cuts of λ DNA have been compared. A common 5′GAGACC3′CTCTGG sequence occurs near each cleavage site. Precise mapping of the cleavages in both DNA strands places the cuts five nucleotides to the left of the upper sequence and one nucleotide to the left of the lower sequence. This enabled us to deduce the following recognition and cleavage specificity of Eco31I: 5 ′ G G T C T C N ↓ 3 ′ C C A G A G N N N N N ↑ 相似文献