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It is shown for the first time that the content of ubiquinone of liver increases (2.5 fold) on dietary administration of the
widely-used industrial Plasticizer diethylhexyl Phthalate to the rat. The increase is localized almost entirely in mitochondria
in which the concentration of the quinone Per mg Protein is 1.7 times the control. IncorPoration of the radioactive Precursor
(acetate) reveals that the biosynthesis of ubiquinone is increased in the livers of Plasticizer-administered animals. The
rate of degradation is not altered. 相似文献
5.
The mechanism of hypercholesterolemia effect of Cu2+ deficiency was studied in rats. There was increased activity of hepatic hydroxymethylglutaryl-coenzyme A reductase and increased
incorporation of labelled acetate into free cholesterol of liver in the Cu2+ deficient rats. Incorporation of label into ester cholesterol was however decreased in the liver. Concentration of bile acids
in the liver was not significantly altered. Increase in the incorporation of labelled acetate into serum cholesterol and increase
in the concentration of cholesterol and apo B in the low density lipoproteins + very low density lipoproteins fractions were
observed. Activity of lipoprotein lipase of the extrahepatic tissues decreased in the Cu2+ deficient rats. 相似文献
6.
Catherine Ronin Herman van Halbeek Johannah GM Mutsaers Johannes F G Vliegenthart 《Glycoconjugate journal》1987,4(3):247-254
The lipid-linked precursor ofN-type glycoprotein oligosaccharides was isolated from porcine thyroid microsomes after in cubation with UDP[3H] Glucose. The carbohydrate was released from dolichol pyrophosphate by mild acid hydrolysis, purified by gel filtration and characterized by 500-MHz1H-NMR spectroscopy in combination with enzymatic degradation. The parent oligosaccharide was found to be Glc3Man9Glc-NAc2. The three glucose residues are present in the linear sequence Glcα1-2Glα1-3 Glc, the latter being α(1-3)-linked to one of the mannose residues. In order to establish the branch location of the triglucosyl unit, the parent compound was digested with jack-bean α-mannosidase. The oligosaccharide product was purified by gel filtration, and identified by1H-NMR as Glc3Man5GlcNAc2 lacking the mannose residues A, D2, B and D3. Therefore, the structure of the precursor oligosaccharide is as follows: $$\begin{gathered} c b a D_1 C 4 \hfill \\ Glc\alpha 1 - 2Glc\alpha 1 - 3Glc\alpha 1 - 3Man\alpha 1 - 2Man\alpha 1 - 2Man\alpha 1 \hfill \\ 3 \swarrow 3 2 1 \hfill \\ Man\alpha 1 - 2Man\alpha 1 Man\beta 1 - 4GlcNAc\beta 1 - 4GlcNAc \hfill \\ D_{2 } A 3 6 \hfill \\ Man\alpha 1 \hfill \\ 6 \hfill \\ Man\alpha 1 - 2Man\alpha 1 \nwarrow 4 \hfill \\ D_3 B \hfill \\ \end{gathered} $$ 相似文献
7.
B. Seshadri Sekhar C. K. Ramakrishna Kurup T. Ramasarma 《Molecular and cellular biochemistry》1990,95(1):61-70
A membrane protein recognized by monoclonal antibody SQM1 was identified in human squamous carcinomas, including those originating in the head and neck (SqCHN), lung and cervix. Cell lines derived from SqCHN of previously untreated patients expressed high amounts of this protein. In contrast, many cell lines established from SqCHN of patients previously treated with chemotherapy and/or radiation showed diminished amounts of this SQM1 protein. The expression of SQM1 antigen was determined in several SgCHN cell lines made resistant by exposure to methotrexate (MTX) in vitro. The parent cell lines all exhibited strong binding to SQM1 antibody. The MTX-resistant sublines showed much lower membrane binding of SQM1. The lowest SQM1 reactivity was found in cell lines with high resistance to MTX and with diminished rate of MTX transport. Some highly MTX-resistant cell lines which had high levels of dihydrofolate reductase, but which retained a high rate of MTX transport, also retained high levels of SQM1 binding. Reduced SQM1 protein was also found in SgCHN cells which developed resistance to the alkylating drug cis-platinum (CDDP) and which showed reduced membrane transport of CDDP. Cell growth kinetics and non-specific antigenic shifts were not responsible for the differences in SQM1 binding between the parent cell lines and their drug-resistant sublines. The finding of a novel protein which is reduced in cells resistant to MTX and CDDP could contribute to our understanding of the basic mechanisms of drug resistance. By detecting SQM1 protein in clinical specimens, it may be possible to monitor the development of drug resistance in tumors.Abbreviations SqCHN
Squamous Carcinoma of the Head and Neck
- MTX
Methotrexate
- CDDP
Cis-Platinum
- DHFR
Dihydrofolate Reductase 相似文献
8.
Circulating antibodies against Faenia rectivirgula, Thermoactinomyces candidus, T. vulgaris and Aspergillus fumigatus were studied in the sera of 14 clinically proven farmer's lung patients and 10 normal controls using three immunological methods. These methods were agar gel double diffusion (DD), biotin-avidin-linked immunosorbent assay (BALISA) and dot-immunobinding assay (DIBA). Agar gel diffusion, the least sensitive of the three methods, failed to detect antibodies in some of the patients, while BALISA detected antibodies even in the normal controls. However, the sensitivity of dot-immunobinding assay was in between DD and BALISA while the specificity was comparable to DD to all the antibodies except against A. fumigatus antigens. Dot-immunobinding assay gave faster results than DD and the blots can be stored as record for longer periods of time without fading. 相似文献
9.
The effect of biotin deficiency on the metabolism of cholesterol was studied in rats fed cholesterol-free and cholesterol-containing
diet. Biotin deficiency induced by feeding raw egg-white resulted in higher cholesterol in the serum and aorta, and higher
high density lipoprotein cholesterol and low density lipoprotein + very low density lipoprotein cholesterol. In the liver,
cholesterol increased only in the cholesterol diet group but not in the cholesterol-free diet group. Levels of triglycerides
were lower in the biotindeficient, cholesterol-free diet group, but triglycerides were elevated in the cholesterol diet group.
Concentration of bile acids in the liver and activity of lipoprotein lipase in the heart and adipose tissue were significantly
decreased in the biotin-deficient rats. Release of lipoproteins into the circulation, incorporation of [1,2-14C] acetate into cholesterol, and activity of plasma lecithin: cholesterol acyl transferase were higher. 相似文献
10.
The antitumour antibiotic, adriamycin, inhibited oxidative phosphorylation in freshly prepared mitochondria from the heart, liver and kidney of the rat. It abolished respiratory control and stimulated ATPase activity. Succinate oxidation by heart mitochondria was extremely sensitive to the drug when hexokinase was present in the reaction medium. The sensitive site has been identified to lie in the region between the succinate dehydrogenase flavoprotein and ubiquinone of the respiratory chain. 相似文献