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1.
Repeated treatment of ethanol for 5 consecutive days has produced significant biochemical changes in the small intestine of the rat. The LDH and SDH were inhibited leading to deficient energy output from the glycolytic pathway and the Krebs cycle. The changes in ammonia metabolic profiles of intestine and blood indicate the presence of hyperammonemia. Enzymatic reactions associated with urea production and the levels of urea were increased. GS activity decreased explaining low levels of glutamine. These studies implicate PNC in producing hyperammonemia during ethanol treatment. 相似文献
2.
Studies on the existence of a pathway in liver and muscle for the conversion of glucose into glycogen without glucose 6-phosphate as an intermediate 总被引:1,自引:1,他引:0 下载免费PDF全文
Gabor J. Antony Indira Srinivasan Hollis R. Williams Bernard R. Landau 《The Biochemical journal》1969,111(4):453-459
Mixtures of (14)C-labelled glucose plus pyruvate were incubated either with rat diaphragm or slices of rat liver. Incorporation of glucose carbon into glycogen was compared with its incorporation into glucose 6-phosphate relative to the incorporation of pyruvate carbon into these metabolic products. There was no preferential incorporation of glucose carbon relative to pyruvate carbon into glycogen compared with glucose 6-phosphate in the liver slices, but there was in diaphragm. On the assumption that glucose 6-phosphate is a necessary intermediate in the conversion of pyruvate carbon into glycogen, this is evidence for the existence in muscle, but not in liver, of more than one pool of glucose 6-phosphate or of a pathway from glucose to glycogen without glucose 6-phosphate as an intermediate. Galactose carbon, relative to pyruvate carbon, was preferentially incorporated into liver glycogen, so that a substrate converted in liver into glycogen without glucose 6-phosphate as an intermediate could be detected by this approach. 相似文献
3.
Neurochemical consequences of repeated ethanol treatment on energy and ammonia metabolism were studied in different regions of rat brain. Energy production was decreased as indicated by lowered lactate dehydrogenase and succinate dehydrogenase activities with possible lacticacidimia. Transamination of alanine and aspartate increased while the deamination of glutamate decreased in all the regions of brain. The deamination of AMP was slightly elevated in cerebral cortex and brain stem while it was inhibited in cerebellum. Ammonia levels were persistently high, despite stepped up glutamine synthesis and ureogenesis. The synergistic action of ammonia during ethanol intoxication is envisaged. 相似文献
4.
Guinea pigs were given ascorbic acid orally in two doses; a low and a high dose. The tissue levels of ascorbic acid-2-sulphate was estimated in these animals after 15 days of feeding and a subsequent deprivation period of 15 days. The specific activity of the enzymes ascorbic acid sulphotransferase and ascorbic acid-2-sulphate sulphohydrolase was studied. During higher ascorbic acid intake, the activity of ascorbic acid sulphotransferase was increased, whereas ascorbic acid-2-sulphate sulphohydrolase showed a decreased activity. But when ascorbic acid intake was lowered or ceased, the activity of the above enzymes showed a reverse pattern. Possible reasons for the lack of antiscorbutic activity of ascorbic acid-2-sulphate in guinea pigs is discussed. 相似文献
5.
6.
Radiomodulatory effect of liposome encapsulated AK-2123 on tumor in mice exposed to hepatocarcinogen 总被引:1,自引:0,他引:1
Alam A Rapthap CC Singha LI Sharan RN Singh V 《Molecular and cellular biochemistry》2005,271(1-2):139-150
An attempt was made to evaluate the whole body -radiation effect on tumor in the presence of free and liposome encapsulated AK-2123, a hypoxic cell radiosensitizer that has widely been used in combination with a number of cancer therapies such as thermotherapy, chemotherapy and radiotherapy. Entrapment efficiency of AK-2123 into liposome was determined by LASER Raman spectroscopy. Cancer induction in mice was carried out by repeated exposure of N-nitrosodiethylamine (DEN) in combination with partial hepatectomy. Parameters such as marker enzymes activities (GGT and AChE), rates of nucleic acid synthesis, viability modification factor and the histology of liver tissues monitored, supported the induction of cancer in liver. In addition, the effect of free as well as liposome encapsulated AK-2123 on haemopoietic parameters were also studied. It was observed that AK-2123 after incorporation into liposome afforded more efficient radiomodulatory effects than that of free AK-2123 as determined by the above-mentioned parameters. Neither free AK-2123 nor liposome encapsulated AK-2123 showed any detectable toxic effects on the mice. Thus, it is seen that treatment of cancer with a combination of radiation, a radiomodifier and a drug delivery system, opens a wide scope for exploitation for the improvement of existing cancer therapies. (Mol Cell Biochem 271: 139–150, 2005) 相似文献
7.
Resurgent Na current flows as voltage-gated Na channels recover through open states from block by an endogenous open-channel blocking protein, such as the NaVβ4 subunit. The open-channel blocker and fast-inactivation gate apparently compete directly, as slowing the onset of fast inactivation increases resurgent currents by favoring binding of the blocker. Here, we tested whether open-channel block is also sensitive to deployment of the DIV voltage sensor, which facilitates fast inactivation. We expressed NaV1.4 channels in HEK293t cells and assessed block by a free peptide replicating the cytoplasmic tail of NaVβ4 (the “β4 peptide”). Macroscopic fast inactivation was disrupted by mutations of DIS6 (L443C/A444W; “CW” channels), which reduce fast-inactivation gate binding, and/or by the site-3 toxin ATX-II, which interferes with DIV movement. In wild-type channels, the β4 peptide competed poorly with fast inactivation, but block was enhanced by ATX. With the CW mutation, large peptide-induced resurgent currents were present even without ATX, consistent with increased open-channel block upon depolarization and slower deactivation after blocker unbinding upon repolarization. The addition of ATX greatly increased transient current amplitudes and further enlarged resurgent currents, suggesting that pore access by the blocker is actually decreased by full deployment of the DIV voltage sensor. ATX accelerated recovery from block at hyperpolarized potentials, however, suggesting that the peptide unbinds more readily when DIV voltage-sensor deployment is disrupted. These results are consistent with two open states in Na channels, dependent on the DIV voltage-sensor position, which differ in affinity for the blocking protein. 相似文献
8.
Chaman Saini Anisuddin Siddiqui Venkatesh Ramesh Indira Nath 《PLoS neglected tropical diseases》2016,10(4)
Background
50% of leprosy patients suffer from episodes of Type 1/ reversal reactions (RR) and Type 2/ Erythema Nodosum Leprosum (ENL) reactions which lead to morbidity and nerve damage. CD4+ subsets of Th17 cells and CD25+FOXP3+ regulatory T cells (Tregs) have been shown to play a major role in disease associated immunopathology and in stable leprosy as reported by us and others. The aim of our study was to analyze their role in leprosy reactions.Methodology and Principle Findings
Quantitative reverse transcribed PCR (qPCR), flowcytometry and ELISA were used to respectively investigate gene expression, cell phenotypes and supernatant levels of cytokines in antigen stimulated PBMC cultures in patients with stable disease and those undergoing leprosy reactions. Both types of reactions are associated with significant increase of Th17 cells and associated cytokines IL-17A, IL-17F, IL-21, IL-23 and chemokines CCL20, CCL22 as compared to matching stable forms of leprosy. Concurrently patients in reactions show reduction in FOXP3+ Treg cells as well as reduction in TGF-β and increase in IL-6. Moreover, expression of many T cell markers, cytokines, chemokines and signaling factors were observed to be increased in RR as compared to ENL reaction patients.Conclusions
Patients with leprosy reactions show an imbalance in Th17 and Treg populations. The reduction in Treg suppressor activity is associated withhigherTh17cell activity. The combined effect of reduced TGF-β and enhanced IL-6, IL-21 cytokines influence the balance between Th17 or Treg cells in leprosy reactions as reported in the murine models and autoimmune diseases. The increase in Th17 cell associated cytokines may contribute to lesional inflammation. 相似文献9.
10.
Ha Pham Indira Singaram Jiachen Sun Arthur Ralko Madalyn Puckett Ashutosh Sharma Alice Vrielink Wonhwa Cho 《Journal of lipid research》2022,63(3):100178
Cholesterol is an essential component of mammalian cell membranes whose subcellular concentration and function are tightly regulated by de novo biosynthesis, transport, and storage. Although recent reports have suggested diverse functions of cellular cholesterol in different subcellular membranes, systematic investigation of its site-specific roles has been hampered by the lack of a methodology for spatiotemporal manipulation of cellular cholesterol levels. Here, we report the development of a new cholesterol depletion system that allows for spatiotemporal manipulation of intracellular cholesterol levels. This system utilizes a genetically encoded cholesterol oxidase whose intrinsic membrane binding activity is engineered in such a way that its membrane targeting can be controlled in a spatiotemporally specific manner via chemically induced dimerization. In combination with in situ quantitative imaging of cholesterol and signaling activity measurements, this system allows for unambiguous determination of site-specific functions of cholesterol in different membranes, including the plasma membrane and the lysosomal membrane. 相似文献