全文获取类型
收费全文 | 889篇 |
免费 | 70篇 |
出版年
2022年 | 6篇 |
2021年 | 15篇 |
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 23篇 |
2017年 | 21篇 |
2016年 | 19篇 |
2015年 | 27篇 |
2014年 | 33篇 |
2013年 | 44篇 |
2012年 | 48篇 |
2011年 | 42篇 |
2010年 | 36篇 |
2009年 | 23篇 |
2008年 | 25篇 |
2007年 | 40篇 |
2006年 | 41篇 |
2005年 | 25篇 |
2004年 | 46篇 |
2003年 | 38篇 |
2002年 | 27篇 |
2001年 | 32篇 |
2000年 | 28篇 |
1999年 | 31篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1996年 | 13篇 |
1995年 | 5篇 |
1994年 | 10篇 |
1993年 | 9篇 |
1992年 | 20篇 |
1991年 | 21篇 |
1990年 | 13篇 |
1989年 | 17篇 |
1988年 | 20篇 |
1987年 | 13篇 |
1986年 | 7篇 |
1985年 | 9篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1975年 | 13篇 |
1973年 | 6篇 |
1972年 | 9篇 |
1970年 | 8篇 |
1969年 | 4篇 |
1966年 | 3篇 |
排序方式: 共有959条查询结果,搜索用时 15 毫秒
61.
Proteins from bovine tissues and biological fluids: defining a reference electrophoresis map for liver,kidney, muscle,plasma and red blood cells 总被引:1,自引:0,他引:1
Talamo F D'Ambrosio C Arena S Del Vecchio P Ledda L Zehender G Ferrara L Scaloni A 《Proteomics》2003,3(4):440-460
A number of high resolution two-dimensional electrophoresis (2-DE) reference maps for bovine tissues and biological fluids have been determined for animals in basal state. Among the 1863 distinct protein features detected in samples of liver, kidney, muscle, plasma and red blood cells, 509 species were identified and associated to 209 different genes. Difficulties in the identification were related to the poorly characterized Bos taurus genome and were solved by a combined matrix-assisted laser desorption/ionisation-mass spectrometry and liquid chromatography-electrospray ionization tandem mass spectrometry approach. The experimental output allowed us to establish a 2-DE database accessible through the World Wide Web network at the URL address (http://www.iabbam.na.cnr.it/Biochem). These reference maps may serve as a tool in future veterinary medical studies aimed at the evaluation of changes in protein repertoire for altered animal physiological conditions and infectious diseases, to the definition of molecular markers for novel diagnostic kits and vaccines, as well as the characterization of protein modifications in bovine materials following technological processes used in the food industry. 相似文献
62.
F?Luna M?Cortés M?Flores B?Hernández A?Trujillo R?DomínguezEmail author 《Reproductive biology and endocrinology : RB&E》2003,1(1):61
The effects on spontaneous ovulation associated with the unilateral or bilateral sectioning of the superior ovarian nerves
(SON) were analyzed in guinea pigs at different time intervals of the estrous cycle. Day 1 of the estrous cycle was defined
as the day when the animal presents complete loss of the vaginal membrane (open vagina). Subsequent phases of the cycle were
determined by counting the days after Day 1. All animals were autopsied on the fifth day of the estrous cycle after surgery.
Sectioning the right, left, or both SONs on day 5 (early luteal phase) resulted in a significant increase in the number of
fresh corpora lutea. Ovulation increased significantly when the left SON (L-SON) was sectioned during late follicular phase
(day 1) and medium luteal phase (day 8). When surgery was performed on days 1 or 8, neither sectioning the right SON (R-SON)
nor sectioning the SON bilaterally had an apparent effect on ovulation rates. Similarly, ovulation rates were not affected
when unilateral (right or left) or bilateral sectioning of the SON was performed during late luteal phase two (day 12). Unilateral
or bilateral sectioning of the SON performed during the early luteal phase (day 5) was associated with a significant decrease
in uterine weight. A comparable effect was observed when the L-SON was sectioned during late follicular phase (day 1), or
medium luteal phase (day 8). No effects on uterine weight were observed when unilateral or bilateral sectioning of the SON
was performed during late luteal phase. Our results suggest that in the guinea pig the SON modulates ovulation, and that the
degree of modulation varies along the estrous cycle. The strongest influence of the SONs on ovulation occurs during early
luteal phase, and decrease thereafter, being absent by late luteal phase. In addition, sectioning the left or the right SON
caused different responses by the ovaries of adult guinea pigs. This paper discusses the mechanisms by which ovulation increased
when the SON was surgically cut. 相似文献
63.
A repressor sequence in the juxtamembrane domain of Flt-1 (VEGFR-1) constitutively inhibits vascular endothelial growth factor-dependent phosphatidylinositol 3'-kinase activation and endothelial cell migration
下载免费PDF全文
![点击此处可从《The EMBO journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Gille H Kowalski J Yu L Chen H Pisabarro MT Davis-Smyth T Ferrara N 《The EMBO journal》2000,19(15):4064-4073
Vascular endothelial growth factor (VEGF) has two highly homologous tyrosine kinase receptors: Flt-1 (VEGFR-1) and KDR (VEGFR-2). KDR is strongly phosphorylated on tyrosines and can transmit mitogenic and motogenic signals following VEGF binding, while Flt-1 is markedly less effective in mediating such functions. To dissect the regions that account for the differences between the two receptors, we generated a series of chimeric Flt-1-KDR molecules. We found that the juxtamembrane region of Flt-1 prevents key signaling functions. When the juxtamembrane region of Flt-1 is replaced by that of KDR, Flt-1 becomes competent to mediate endothelial cell migration and phosphatidylinositol 3'-kinase activation in response to VEGF. Further mutational analysis shows that a short divergent sequence is responsible for such repressor function. However, mutant Flt-1 receptors lacking this sequence do not transmit effective proliferative signals, suggesting that this receptor function is regulated separately. These results define a novel functional domain that serves to repress Flt-1 activity in endothelial cells. 相似文献
64.
65.
Lorda-Sanchez I Garcia-Ruiz PJ Rodriguez de Alba M Montoya J Playan A Sarasa JL Trujillo MJ Sanz R Ramos C Ayuso C 《Genetic counseling (Geneva, Switzerland)》2000,11(3):261-265
A MELAS phenotype and a paternal inherited inversion of chromosome 10 in a female patient: We describe a patient suffering from encephalomyopathy with overlapping symptoms, including MELAS and Kearn-Sayre syndrome features. Mutations in tRNA LEU (UUR) were not found in mtDNA of blood cells, suggesting a different genetic defect. Cytogenetic studies revealed a paternal inherited pericentric inversion of chromosome 10 (p13;q22) pat. Although the presence of the same inversion in the father and in the apparently asymptomatic sister does rather suggest that the concurrence of the mitochondrial disease in the patient was due to chance, some alternative explanations to associate both events might be proposed. 相似文献
66.
The pathogenesis-related accumulation of superoxide radical anions (O·−
2) and hydrogen peroxide (H2O2) was comparatively analyzed in a barley line (Hordeum vulgare L. cv Sultan-5) carrying the powdery mildew (Blumeria graminis f.sp. hordei, Speer, Bgh) resistance gene Mla12, and in susceptible mutants defective in Mla12 or in genes “required for Mla12-specified disease resistance” (Rar1 and Rar2). In-situ localization of reactive oxygen intermediates was performed both by microscopic detection of azide-insensitive
nitroblue tetrazolium (NBT) reduction or diaminobenzidine (DAB) polymerization, and by an NBT-DAB double-staining procedure.
The Mla12-mediated hypersensitive cell death occurred either in attacked epidermal cells or adjacent mesophyll cells of wild-type plants.
Whole-cell H2O2 accumulation was detected in dying cells, while O·−
2 emerged in adjacent cells. Importantly, all susceptible mutants lacked these reactions. An oxalate oxidase, which is known
to generate H2O2 and has been implicated in barley resistance against the powdery mildew fungus, was not differentially expressed between
the wild type and all mutants. The results demonstrate that the Rar1 and Rar2 gene products, which are control elements of R-gene-mediated programmed cell death, also control accumulation of reactive oxygen intermediates but not the pathogenesis-related
expression of oxalate oxidase.
Received: 7 January 2000 / Accepted: 2 June 2000 相似文献
67.
Rod and cone photoreceptors project from the outer retinal surface into a
carbohydrate-rich interphotoreceptor matrix (IPM). Unique IPM
glycoconjugates are distributed around rods and cones. Wheat germ
agglutinin (WGA) strongly decorates the rod matrix domains and weakly
decorates the cone matrix domains. This study characterizes the major
WGA-binding glycoprotein in the human IPM, which we refer to as SPACR
(sialoprotein associated with cones and rods). SPACR, which has a molecular
weight of 147 kDa, was isolated and purified from the IPM by lectin
affinity chromatography. A polyclonal antibody to SPACR was prepared that
colocalizes in tissue preparations with WGA-binding domains in the IPM.
Sequential digestion of SPACR with N- and O- glycosidases results in a
systematic increase in electrophorectic mobility, indicating the presence
of both N- and O-linked glycoconjugates. Complete deglycosylation results
in a reduction in the relative molecular mass of SPACR by about 30%.
Analysis of lectin binding allowed us to identify some of the structural
characteristics of SPACR glycoconjugates. Treatment with neuraminidase
exposes Galbeta1- 3GalNAc disaccharide as indicated by positive peanut
agglutinin (PNA) staining, accompanied by the loss of WGA staining. Maackia
amurensis agglutinins (MAA-1 and MAA-2), specific for sialic acid in
alpha2-3 linkage to Gal, bind SPACR, while Sambucus nigra agglutinin (SNA),
specific for alpha2-6 linked sialic acid, does not, indicating that the
dominant glycoconjugate determinant on SPACR is the O-linked carbohydrate,
NeuAcalpha2-3Galbeta1-3GalNAc. The abundance of sialic acid in SPACR
suggests that this glycoprotein may contribute substantially to the
polyanionic nature of the IPM. The carbohydrate chains present on SPACR
could also provide sites for extensive crosslinking and participate in the
formation of the ordered IPM lattice that surrounds the elongate
photoreceptors projecting from the outer retinal surface.
相似文献
68.
The recent structure determinations of the mammalian effector enzyme adenylyl cyclase reveal the structure of its catalytic core, provide new insights into its catalytic mechanism and suggest how diverse signaling molecules regulate its activity. 相似文献
69.
High affinity RGD-binding sites at the plasma membrane of
Arabidopsis thaliana
links the cell wall 总被引:6,自引:0,他引:6
Hervé Canut Antoine Carrasco Jean-Philippe Galaud Catherine Cassan Huguette Bouyssou Natalio Vita Pascual Ferrara Rafael Pont-Lezica 《The Plant journal : for cell and molecular biology》1998,16(1):63-71
The heptapeptide Tyr-Gly- Arg-Gly-Asp- Ser-Pro containing the sequence Arg-Gly-Asp (RGD – the essential structure recognised by animal cells in substrate adhesion molecules) was tested on epidermal cells of onion and cultured cells of Arabidopsis upon plasmolysis. Dramatic changes were observed on both types of cells following treatment: on onion cells, Hechtian strands linking the cell wall to the membrane were lost, while Arabidopsis cells changed from concave to convex plasmolysis. A control heptapeptide Tyr-Gly-Asp-Gly-Arg-Ser-Pro had no effect on the shape of plasmolysed cells. Protoplasts isolated from Arabidopsis cells agglutinate in the presence of ProNectinF, a genetically engineered protein of 72 kDa containing 13 RGD sequences: several protoplasts may adhere to a single molecule of ProNectinF. The addition of the RGD-heptapeptide disrupted the adhesion between the protoplasts. Purified plasma membrane from Arabidopsis cells exhibits specific binding sites for the iodinated RGD-heptapeptide. The binding is saturable, reversible, and two types of high affinity sites (Kd1 1 nM, and Kd2 40 nM) can be discerned. Competitive inhibition by several structurally related peptides and proteins noted the specific requirement for the RGD sequence. Thus, the RGD-binding activity of Arabidopsis fulfils the adhesion features of integrins, i.e. peptide specificity, subcellular location, and involvement in plasma membrane-cell wall attachments. 相似文献
70.
Methods for surveillance of fetal alcohol syndrome: The fetal alcohol syndrome surveillance network II (FASSNetII) – Arizona,Colorado, New York, 2009 ‐ 2014
下载免费PDF全文
![点击此处可从《Birth defects research. Part A, Clinical and molecular teratology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Leslie A. O'Leary Linnette Ortiz April Montgomery Deborah J. Fox Christopher Cunniff Margaret Ruttenber April Breen Sydney Pettygrove Don Klumb Charlotte Druschel Jaime L. Frías Luther K. Robinson Jacquelyn Bertrand Kelly Ferrara Maureen Kelly Suzanne M. Gilboa F. John Meaney for the FASSNetII 《Birth defects research. Part A, Clinical and molecular teratology》2015,103(3):196-202