全文获取类型
收费全文 | 272篇 |
免费 | 14篇 |
出版年
2022年 | 3篇 |
2018年 | 3篇 |
2016年 | 4篇 |
2015年 | 8篇 |
2013年 | 7篇 |
2012年 | 12篇 |
2011年 | 10篇 |
2010年 | 8篇 |
2009年 | 8篇 |
2008年 | 8篇 |
2007年 | 19篇 |
2006年 | 20篇 |
2005年 | 16篇 |
2004年 | 11篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1969年 | 5篇 |
1967年 | 2篇 |
1959年 | 4篇 |
1954年 | 2篇 |
1953年 | 2篇 |
1952年 | 2篇 |
1951年 | 2篇 |
1949年 | 3篇 |
1939年 | 2篇 |
1937年 | 2篇 |
1936年 | 3篇 |
排序方式: 共有286条查询结果,搜索用时 15 毫秒
91.
92.
Recently, we showed that holo HDL particle uptake and resecretion occur in physiologically relevant cell lines and that HDL uptake is mediated by scavenger receptor class B type I (SR-BI). Furthermore, we established that HDL resecretion is accompanied by [(3)H]cholesterol efflux. This study shows that HDL uptake and resecretion occur even when LDL uptake and cholesterol trafficking are disturbed. First, we used a set of inhibitors that block cholesterol transport out of the lysosome: chloroquine, imipramine, U18666A, and monensin. In all cases, HDL retroendocytosis occurred and HDL resecretion mediated [(3)H]cholesterol efflux, although to a lesser extent. Second, cell lines carrying somatic mutations in intracellular cholesterol transport were used: CHO 2-2 and CHO 3-6 cells accumulated LDL-derived lipid in the lysosome but showed all components of HDL retroendocytosis. SR-BI overexpression increased HDL uptake and resecretion and [(3)H]cholesterol efflux in these mutant cells. Finally, we used Niemann-Pick type C (NPC) patient fibroblast cells, which carry a defect in cholesterol transfer out of the lysosome. NPC fibroblast cells accumulate cholesterol in the lysosome as a result of a mutation in the NPC1 gene. Despite disturbed intracellular cholesterol transfer, NPC fibroblast cells exhibited HDL retroendocytosis and [(3)H]cholesterol efflux via HDL resecretion, although to a lesser extent. Thus, [(3)H]cholesterol efflux via HDL resecretion is independent of the cholesterol uptake pathway via the LDL receptor and may be an alternative way to remove excess cholesterol. 相似文献
93.
Wada Y Azadi P Costello CE Dell A Dwek RA Geyer H Geyer R Kakehi K Karlsson NG Kato K Kawasaki N Khoo KH Kim S Kondo A Lattova E Mechref Y Miyoshi E Nakamura K Narimatsu H Novotny MV Packer NH Perreault H Peter-Katalinic J Pohlentz G Reinhold VN Rudd PM Suzuki A Taniguchi N 《Glycobiology》2007,17(4):411-422
Mass spectrometry (MS) of glycoproteins is an emerging field in proteomics, poised to meet the technical demand for elucidation of the structural complexity and functions of the oligosaccharide components of molecules. Considering the divergence of the mass spectrometric methods employed for oligosaccharide analysis in recent publications, it is necessary to establish technical standards and demonstrate capabilities. In the present study of the Human Proteome Organisation (HUPO) Human Disease Glycomics/Proteome Initiative (HGPI), the same samples of transferrin and immunoglobulin-G were analyzed for N-linked oligosaccharides and their relative abundances in 20 laboratories, and the chromatographic and mass spectrometric analysis results were evaluated. In general, matrix-assisted laser desorption/ionization (MALDI) time-of-flight MS of permethylated oligosaccharide mixtures carried out in six laboratories yielded good quantitation, and the results can be correlated to those of chromatography of reductive amination derivatives. For underivatized oligosaccharide alditols, graphitized carbon-liquid chromatography (LC)/electrospray ionization (ESI) MS detecting deprotonated molecules in the negative ion mode provided acceptable quantitation. The variance of the results among these three methods was small. Detailed analyses of tryptic glycopeptides employing either nano LC/ESI MS/MS or MALDI MS demonstrated excellent capability to determine site-specific or subclass-specific glycan profiles in these samples. Taking into account the variety of MS technologies and options for distinct protocols used in this study, the results of this multi-institutional study indicate that MS-based analysis appears as the efficient method for identification and quantitation of oligosaccharides in glycomic studies and endorse the power of MS for glycopeptide characterization with high sensitivity in proteomic programs. 相似文献
94.
Ozers MS Marks BD Gowda K Kupcho KR Ervin KM De Rosier T Qadir N Eliason HC Riddle SM Shekhani MS 《Biochemistry》2007,46(3):683-695
95.
96.
DNA extraction from minute hymenopterans and their larvae is difficult and challenging because of their small size indicating a low amount of starting material. Hence, 11 DNA extraction methods were compared to determine their efficacy in isolating DNA. Success of each method was scored on a 2% agarose gel after PCR of the cox 1 mitochondrial locus. A silica-membrane-based approach was the most successful, followed by a method using a combination of incubation buffers and a method using magnetic beads. The method using buffers was the most cost- and time effective. Using this method, larvae from Eucalyptus seed capsule galls could be assigned a role (parasitoid, gall former or inquiline) in the gall-inhabiting complex. 相似文献
97.
98.
Berg CP Stein GM Keppeler H Gregor M Wesselborg S Lauber K 《Apoptosis : an international journal on programmed cell death》2008,13(1):63-75
There is growing evidence that the onset of autoimmune disorders can be linked to the inefficient removal of apoptotic cells.
Since defects in the elimination of apoptotic cells lead to secondary necrosis and subsequent release of intracellular components,
this might explain the generation of autoantibodies against intracellular antigens. Accordingly, we wanted to investigate,
whether antibodies from patients with the autoimmune liver disease primary biliary cirrhosis (PBC) recognize self-proteins
generated and released during apoptosis. Using Western blot analyses we could detect intracellular antigens with serum IgG
from PBC patients but not with serum IgG from healthy donors in lysates of Jurkat T-leukemia, HepG2 hepatoma, and HT-29 colon-carcinoma
cells. Interestingly, PBC serum IgG also recognized caspase substrates in cells undergoing apoptosis induced by staurosporine
or TRAIL (TNF-related apoptosis inducing ligand). In addition to intracellular antigens, serum IgG from PBC patients detected
caspase-dependent antigens in the supernatants of apoptotic (secondary necrotic) cells and antigens on the surface of apoptotic
Jurkat cells. Among the caspase substrates recognized by PBC serum IgG we could identify the components PDC-E2 and -E1β of
the known autoantigen PDC (pyruvate dehydrogenase complex). Thus, caspase-mediated processing of intracellular proteins might
generate de novo autoantigens that upon release contribute to the generation of autoantibodies and autoimmune diseases as PBC.
Christoph Peter Berg and Gerburg Maria Stein contributed equally to this paper and share first authorship.
Sebastian Wesselberg and Kirsten Lauber share equal senior authorship. 相似文献
99.
Tomofumi Kurokawa Manfred Wuhrer Günter Lochnit Hildegard Geyer Jürgen Markl Rudolf Geyer 《European journal of biochemistry》2002,269(22):5459-5473
Keyhole limpet (Megathura crenulata) hemocyanin (KLH), an extracellular respiratory protein, is widely used as hapten carrier and immune stimulant. Although it is generally accepted that the sugar constituents of this glycoprotein are likely to be implicated in the antigenicity and biomedical properties of KLH, knowledge of its carbohydrate structure is still limited. Therefore, we have investigated the N-linked oligosaccharides of KLH. Glycan chains were enzymatically liberated from tryptic glycopeptides, pyridylaminated and separated by two-dimensional HPLC. Only neutral oligosaccharides were obtained and characterized by carbohydrate constituent and methylation analyses, MALDI-TOF-MS, ESI-ion trap-MS and sequential exoglycosidase digestion. The results revealed that KLH is carrying high mannose-type glycans and truncated sugar chains derived thereof. As a characteristic feature, a number of the studied N-glycans contained a Gal(beta1-6)Man-unit which has not been found in glycoprotein-N-glycans so far. Hence, our studies demonstrate that this marine mollusk glycoprotein is characterized by a unique oligosaccharide pattern comprising, in part, novel structural elements. 相似文献
100.
A novel strategy for the identification of protein–DNA contacts by photocrosslinking and mass spectrometry
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)
Photochemical crosslinking is a method for studying the molecular details of protein–nucleic acid interactions. In this study, we describe a novel strategy to localize crosslinked amino acid residues that combines laser-induced photocrosslinking, proteolytic digestion, Fe3+-IMAC (immobilized metal affinity chromatography) purification of peptide–oligodeoxynucleotide heteroconjugates and hydrolysis of oligodeoxynucleotides by hydrogen fluoride (HF), with efficient matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The new method is illustrated by the identification of the DNA-binding site of the restriction endonuclease MboI. Photoactivatable 5-iododeoxyuridine was incorporated into a single site within the DNA recognition sequence (GATC) of MboI. Ultraviolet irradiation of the protein–DNA complex with a helium/cadmium laser at 325 nm resulted in 15% crosslinking yield. Proteolytic digestion with different proteases produced various peptide–oligodeoxynucleotide adducts that were purified together with free oligodeoxynucleotide by Fe3+-IMAC. A combination of MS analysis of the peptide–nucleosides obtained after hydrolysis by HF and their fragmentation by MS/MS revealed that Lys209 of MboI was crosslinked to the MboI recognition site at the position of the adenine, demonstrating that the region around Lys209 is involved in specific binding of MboI to its DNA substrate. This method is suitable for the fast identification of the site of contact between proteins and nucleic acids starting from picomole quantities of crosslinked complexes. 相似文献