全文获取类型
收费全文 | 192篇 |
免费 | 12篇 |
国内免费 | 3篇 |
出版年
2021年 | 1篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 6篇 |
2014年 | 6篇 |
2013年 | 8篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 13篇 |
2009年 | 12篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 5篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 5篇 |
1999年 | 3篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1977年 | 3篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有207条查询结果,搜索用时 15 毫秒
1.
2.
Jan Holgersson Michael E Breimer Anita Jacobsson Lola Svensson Ami Ulfvin Bo E Samuelsson 《Glycoconjugate journal》1990,7(6):601-608
Total non-acid glycolipid fractions and total sodium dodecylsulphate (SDS) solubilized protein fractions were isolated from human thrombocytes obtained from single human donors having different blood group A1/A2 phenotypes. The blood group A glycolipid antigens were characterized by immunostaining of thin layer plates with different monoclonal anti-A antibodies. The glycoproteins carrying blood group A epitopes were identified by SDS-PAGE and Western blot analysis using a monoclonal anti-A antibody. Blood group A glycolipid antigens were found in both A1 and A2 thrombocytes but the A2 individuals expressed at least ten times less A glycolipids compared to the A1 individuals. Expression of A type 3/4 chain and small amounts of A type 1 chain glycolipids were seen in thrombocytes of both A1 and A2 individuals, while the type 2 chain A glycolipids appeared to be missing from the A2 thrombocytes. Blood group A reactive glycoproteins were only found in thrombocytes of A1 individuals and could not be detected in A2 individuals or a blood group O individual. The major blood group A glycoprotein were found as a double band migrating in the 130 kDa region.Abbreviations SDS
sodium dodecyl sulfate
- PAGE
polyacrylamide gel electrophoresis
- HPTLC
high performance thin layer chromatography
- CBB
Coomassie brilliant blue
- GVH
graft versus host
Part of this work was presented at the Xth International Symposium on Glycoconjugates, Jerusalem, Israel. September, 1989.In the short hand designation for glycolipids, the letter indicate blood group determinant, the first numeral, the number of sugar residues, and the second numeral, the type of carbohydrate chain. Thus, A-6-1 means a hexaglycosylceramide with a blood group A determinant based on the type 1 carbohydrate chain. 相似文献
3.
Karin Lindström Albert E. G. Kr. Von Dem Borne Michael E. Breimer Bertil Cedergren Yasuto Okubo Lennart Rydberg Susann Teneberg Bo E. Samuelsson 《Glycoconjugate journal》1992,9(6):325-329
A 12-week-old fetus and one 17-week-old fetus + placenta were obtained after spontaneous abortions from two women of blood group p. The 17-week-old fetus was dissected into intestine, liver, brain and residual tissue. Nonacid glycosphingolipid fractions were prepared from the tissues. Glycolipid characterization was carried out using thin layer chromatography immunostained with monoclonal antibodies and bacteria and by1H NMR spectroscopy and mass spectrometry. In the placental fraction substantial amounts of globotetraosylceramide (P-antigen) and globotriaosylceramide (Pk-antigen) were identified. In contrast, the fetuses contained only trace amounts of these structures, as revealed by immunostaining. These results indicate that the primary target for the antibodies of the anti-Tja serum is the placenta tissue, resulting in termination of the pregnancy. 相似文献
4.
Thymine lesions produced by ionizing radiation in double-stranded DNA 总被引:11,自引:0,他引:11
A DNA glycosylase which catalyzes the release of thymine residues damaged by ring saturation, fragmentation, or ring contraction from double-stranded DNA has been used to characterize such base derivatives in gamma-irradiated DNA. It is shown by chromatographic analysis that irradiation of DNA in neutral solution generates the ring-saturated forms cis-thymine glycol, trans-thymine glycol, and a monohydroxydihydrothymine, probably 6-hydroxy-5,6-dihydrothymine. The latter compound is only observed after irradiation under hypoxic conditions. The ring-contracted thymine derivative 5-hydroxy-5-methylhydantoin is also formed, and it is the major lesion after irradiation of DNA under O2. Ring-fragmented products such as methyltartronylurea were only generated in small quantities. Isolation and analysis of the DNA from gamma-irradiated human cells also revealed the formation of ring-saturated thymine derivatives, but 5-hydroxy-5-methylhydantoin was not found in this case. 相似文献
5.
Chemical and immunological identification of glycolipid-based blood group ABH and Lewis antigens in human kidney 总被引:2,自引:0,他引:2
A polar non-acid glycolipid fraction has been isolated from human kidney. It was shown by thin-layer chromatography to be a mixture of glycolipids having more than four carbohydrate residues. Immunological testing revealed strong blood group Lea and A activity together with weak Leb, P1 and B activity. Mass spectrometry of the permethylated and permethylated-reduced (LiAlH4) glycolipid fraction showed that the two major components were a five sugar fucolipid (isomer of Lea) and a glycolipid having four hexoses and one N-acetylhexosamine. In addition, blood group Leb, B and A type hexaglycosylceramides were present. Evidence for small amounts of more complex glycolipids was also found. Acid degradation and gas chromatography of the native fraction revealed fucose, glucose, galactose, N-acetylglucosamine and N-acetylgalactosamine. This is the first chemical isolation and characterization of complex blood group active glycolipids in human kidney. The existence of these molecules is discussed in view of their possible role as transplantation antigens. 相似文献
6.
Characterization of the Scavenger Receptor on Bovine Cerebral Endothelial Cells In Vitro 总被引:1,自引:0,他引:1
H. E. de Vries†J. Kuiper† A. G. de BoerTh. J. C. van Berkel† D. D. Breimer 《Journal of neurochemistry》1993,61(5):1813-1821
Abstract— Primary cultures of bovine brain capillary endo-thelial cells (BCEC), possessing tight junctions and high levels of γ-glutamyl transpeptidase, were used as an in vitro model for the blood-brain barrier. The interaction of acetylated low density lipoprotein (AcLDL) with BCEC was studied to characterize the scavenger receptor on these cells. A saturable high affinity binding site was found with a dissociation constant of AcLDL of 5.4 μg/ml (3.1 n M ) and a maximal binding ranging from 284 to 626 ng of AcLDL/mg of cell protein for eight primary cultures, and independent of the presence of calcium. Cell association was coupled to degradation, and both could be effectively competed for by polyinosinic acid and AcLDL but not by low density lipoprotein or by high density lipoprotein. Prolonged incubation showed an accumulation of the ligand in the cells. The rate of degradation of AcLDL was ∼ 10–20-fold lower in BCEC than that of peripheral endothelial cells. No evidence for lysosomal degradation could be obtained. Binding of 1,1'-dioctadecyl-3,3,3,3'-tetramethylindocar-boxyamine perchlorate-labeled AcLDL by BCEC was observed, which could be competed for by an excess of un-labeled AcLDL and polyinosinic acid. We have shown that in vitro BCEC possesses specific binding sites for AcLDL, whereas these cells show a relatively low degradative capacity. 相似文献
7.
8.
Enzymatic excision from gamma-irradiated polydeoxyribonucleotides of adenine residues whose imidazole rings have been ruptured 总被引:13,自引:7,他引:6
下载免费PDF全文
![点击此处可从《Nucleic acids research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
L H Breimer 《Nucleic acids research》1984,12(16):6359-6367
The main forms of base damage in polydeoxyadenylic acid gamma-irradiated under hypoxic conditions are due to saturation and fragmentation of the adenine imidazole ring. An irradiated polymer was annealed with an equimolar amount of poly (dT) to generate a double-stranded polydeoxyribonucleotide containing scattered damaged base residues. On incubation of the latter with partially purified cell extracts of E.coli, imidazole ring-opened adenine, i.e. 4,6-diamino-5-formamidopyrimidine, was released in free form by a DNA glycosylase activity. The enzyme has been purified 4,500-fold, has Mr = 29,000, and appears to be identical with the previously described DNA repair enzyme formamidopyrimidine-DNA glycosylase. 相似文献
9.
The changes in germination, peroxidase activity and isoperoxidase spectrum have been studied in apple embryos at 5°C (stratification) and at 20°C in the presence or absence of seed coats. The embryo dormancy is progressively released at 5°C, but not at 20°C. The peroxidase activity in embryos covered with seed coats is very low at 5°C as well as at 20°C which corresponds to a restricted number of isoenzymes. In isolated embryos the peroxidase activity increases significantly. This is due to an increase in both the number and the activity of the isoperoxidases and it is more pronounced at 20°C than at 5°C. The obtained results suggest that the soluble peroxidases are not involved in the process of the release of embryo dormancy. The variations observed are attributed to the growth process following germination, which can occur even at low temperature. 相似文献
10.
AB Kane RP Stanton EG Raymond ME Dobson ME Knafelc JL Farber 《The Journal of cell biology》1980,87(3):643-651
The relationship between intracellular lysosomal rupture and cell death caused by silica was studied in P388d(1) macrophages. After 3 h of exposure to 150 μg silica in medium containing 1.8 mM Ca(2+), 60 percent of the cells were unable to exclude trypan blue. In the absence of extracellular Ca(2+), however, all of the cells remained viable. Phagocytosis of silica particles occurred to the same extent in the presence or absence of Ca(2+). The percentage of P388D(1) cells killed by silica depended on the dose and the concentration of Ca(2+) in the medium. Intracellular lyosomal rupture after exposure to silica was measured by acridine orange fluorescence or histochemical assay of horseradish peroxidase. With either assay, 60 percent of the cells exposed to 150 μg silica for 3 h in the presence of Ca(2+) showed intracellular lysosomal rupture, was not associated with measureable degradation of total DNA, RNA, protein, or phospholipids or accelerated turnover of exogenous horseradish peroxidase. Pretreatment with promethazine (20 μg/ml) protected 80 percent of P388D(1) macrophages against silica toxicity although lysosomal rupture occurred in 60-70 percent of the cells. Intracellular lysosomal rupture was prevented in 80 percent of the cells by pretreatment with indomethacin (5 x 10(-5)M), yet 40-50 percent of the cells died after 3 h of exposure to 150 μg silica in 1.8 mM extracellular Ca(2+). The calcium ionophore A23187 also caused intracellular lysosomal rupture in 90-98 percent of the cells treated for 1 h in either the presence or absence of extracellular Ca(2+). With the addition of 1.8 mM Ca(2+), 80 percent of the cells was killed after 3 h, whereas all of the cells remained viable in the absence of Ca(2+). These experiments suggest that intracellular lysosomal rupture is not causally related to the cell death cause by silica or . Cell death is dependent on extracellular Ca(2+) and may be mediated by an influx of these ions across the plasma membrane permeability barrier damaged directly by exposure to these toxins. A23187相似文献