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1.
Polypeptide composition and endogenous phosphorylation were investigated in the subfractions of rat brain myelin isolated by either discontinuous or continuous sucrose density gradient centrifugation of myelin. Similarly, a myelin-like membrane fraction (SN4) was also studied. Observations were made that strongly indicated the presence of a calcium-stimulated protein kinase in a highly purified myelin preparation and which exclusively phosphorylated myelin basic proteins of the membrane preparation. Adenosine cyclic 3',5'-phosphate (cAMP) stimulated kinase on the other hand was found to be considerably enriched in the myelin-like membrane fraction. Although this latter enzyme is also capable of phosphorylating the basic proteins, its effect was at least 5 times weaker compared to the calcium-stimulated myelin protein kinase. Within the gradient subfractions there appeared a close relation between the amount of basic proteins and their calcium-stimulated phosphorylation; a similar relationship, however, was not obtained in the case of cAMP-dependent phosphorylation of myelin basic proteins. The former (i.e., Ca2+-stimulated phosphorylation) was found to require a protein factor that functionally resembled calmodulin. The results thus raises an interesting possibility of the presence of calmodulin-like proteins and a calcium-stimulated protein kinase in adult myelin membrane from mammalian brain, both of which have been hitherto unrecognized constituents of myelin membranes. 相似文献
2.
H G Giles S Sandrin B M Kapur J J Thiessen 《Canadian journal of physiology and pharmacology》1987,65(12):2491-2493
Ethanol was administered intravenously to rabbits. The concentration of ethanol, determined by gas chromatographic analysis, in lacrimal fluid was shown to reflect the concentration in plasma. The vapour above lacrimal fluid was analyzed in situ by the use of a small resistivity sensor that measures ethanol vapours. After a dose of approximately 750 mg/kg, the metabolic rates of ethanol determined by gas chromatographic analysis of plasma (226 +/- 13 mg.kg-1.h-1) and by eye ethanol vapour analysis (210 +/- 8 mg.kg-1.h-1) were virtually identical. The data suggest that ethanol eye vapour analysis may be an attractive, noninvasive method for the determination of ethanol in animals. 相似文献
3.
G. Thiessen H. Thiessen H. J. Dowidat L. Luciano E. Reale 《Histochemistry and cell biology》1970,23(2):171-175
Zusammenfassung Ratten wurden 50–80 c 59Fe-Citrat in die caudale Vene injiziert. Nach 3–5tägigem Einbau des markierten Eisens in das Hämoglobin wurden Milz-Blöckchen (2 × 2 × 5 mm) 2 Std in GA vorfixiert oder in Hanks-Lösung (= Kontrolle) überführt. Ein Teil der Blöckchen wurde anschließend in OsO4-Lösung nachfixiert.Die autoradiographischen Ergebnisse zeigen eine Diffusion des Hämoglobins vom unfixierten Zentrum zur Peripherie des Blöckchens.Aktivitätsbestimmungen, die am ganzen Blöckchen, dessen abgetrennten zentralen und peripheren Anteilen, sowie im Überstand vorgenommen wurden, bestätigen diese Diffusion. Während der OsO4-Nachfixierung erfolgte ein weiterer Verlust des markierten Hämoglobins aus dem zentralen Teil des Blöckchens, nicht aber aus der vorfixierten Peripherie.
The diffusion of 59Fe-labelled hemoglobin, an artefact of the fixation with glutaraldehyde
Summary Injections of 50–80 c 59Fe-citrate into the caudale vein of rats were performed. After 3–5 days of 59Fe incorporation into the hemoglobin the spleen was taken off, cut in small blocks (2 × 2 × 5 mm) and prefixed for 2 hours in GA or transfered into Hankssolution (= control). Later on some blocks of the spleen were postfixed in OsO4 solution.A diffusion of the hemoglobin from the unfixed center to the peripheral tissue of the spleen-block is demonstrated by autoradiographic results.After measuring the radioactivity of the total spleen-block of the separated central and peripherical parts as well as their supernatants a diffusion was confirmed. A further loss of the labelled hemoglobin has been observed during the OsO4 postfixation from the central part of the spleen-block, but not from the prefixed periphery.相似文献
4.
Myelin isolated from the central and peripheral nervous system contains a Mg2+-dependent protein kinase that catalyses phosphorylation of myelin-specific proteins. This phosphorylation is markedly stimulated by Ca2+ but not by cyclic AMP. Evidence was obtained that suggested an involvement of calmodulin-like protein in the stimulatory effects of Ca2+ on myelin phosphorylation. 相似文献
5.
Summary The present investigation was designed to allow a critical comparison of the cytochemical behaviour of commercially available acriflavine dye samples and pure acriflavine and proflavine dyes, regarding their application in automated cell analysis. Thin layer chromatography, NMR-spectroscopy and mass-spectrometry were applied for the identification of the dye composition.This study includes (1) a column chromatographic technique for the purification of larger dye quantities, (2) the investigation of the photodecomposition of different dye samples, and (3) the evaluation of the influence of various acriflavine/proflavine dye concentrations (1.6·10–3–4·10–6 mol/l) on to the emission spectrum of stained unhydrolyzed and hydrolyzed chicken erythrocytes.The commercially available acriflavine dye samples showed a much higher reduction in fluorescence intensity than the pure dyes, whereby proflavine faded less than acriflavine. Photodecomposition is markably influenced by dye impurities. Fluorescence emission spectra were registered at various acriflavine and proflavine dye concentrations for unhydrolyzed and hydrolyzed chicken erythrocytes in order to investigate the dye-dye interaction and the behaviour of the cellular DNA-dye complex. Proflavine showed a similar spectral behaviour as acriflavine. The dye concentration-dependent spectral behaviour of the DNA-dye complex of these fluorochromes seems to be a very critical factor. A comparison of quantitative fluorescence measurements can only be performed by staining cells with the same dye quality, because automated cytology requires reproducible information of cells in machinesensible terms.This investigation was supported by a grant from the Bundesministerium für Forschung und Technologie (01 VH 065) 相似文献
6.
Summary The present investigation was designed to allow a critical comparison of the dye purity of six commerical acriflavine samples. Thin layer chromatography, absorption-, IR- and NMR-spectroscopy were applied for the identification of dye components and impurities. Ambiguities regarding the purity of the acriflavine samples have been resolved, showing that: (a) The finding permits the conclusion, that all analyzed samples of the fluorochrome acriflavine are characterized by a two-component dye pattern (acriflavine II and proflavine III), and contain fluorescent impurities. (b) The dye component III was the main component of only one dye sample.The effectiveness of these experiments is concerned with making automated microfluorometric measurement of cells stained with pure dye fractions more quantitative and reproduceable.This investigation was supported by a grant from the Bundesministerium für Forschung und Technologie (01 VH 065) 相似文献
7.
Jolanda?HM?van Bilsen Josée?PA?Wagenaar-Hilbers Maarten?JF?van der Cammen Mariska?EA?van Dijk Willem?van Eden Marca?HM?WaubenEmail author 《Arthritis research & therapy》2002,4(4):R2
We have recently found that matrix metalloproteinases (MMPs) are targets for T-cell and B-cell reactivity in experimental
arthritis. In the present article, we investigate whether modulation of MMP-specific T-cell responses could influence the
course of adjuvant arthritis (AA). Lewis rats were treated nasally with MMP peptides prior to or after AA induction. Administration
of the MMP-10 or the MMP-16 peptide prior to AA induction reduced the arthritic symptoms. In contrast, administration of the
MMP-10 peptide after AA induction aggravated the arthritic symptoms. The present study shows the possible usefulness of MMP
peptides for immunotherapy. However, a clear understanding of proper timing of peptide administration is crucial for the development
of such therapies. 相似文献
8.
Del Thiessen 《Human nature (Hawthorne, N.Y.)》1994,5(2):167-202
Human females are generally reserved in their sexuality, in keeping with their heavy investment in reproduction. Males tend to be less reserved. Relative to males, however, females demonstrate more variability in sexuality and are more likely to inhibit or express high levels of sexuality. The heightened variability may in part originate with genetic mechanisms that predispose females toward greater variability (the Lyon hypothesis). Menarche, menstrual cycles, menopause, food reactions, responses to living conditions, reactions to cultural factors, and responses to sexual stimuli and potential mates are unique to or are more variable among females than males. There is a correlation between the variation expressed and female reproductive potential—females tend to shift dramatically from sexual inhibition to sexual expression. Females apparently track the quality of the environment and link their sexuality to reproductive opportunities. Successful male reproduction depends less on quality environments and more on the availability of females. In short, females track the environment; males track the females. 相似文献
9.
A study of bacterial surface oligosaccharides were investigated among
different strains of Neisseria gonorrhoeae to correlate structural features
essential for binding to the MAb 2C7. This epitope is widely expressed and
conserved in gonococcal isolates, characteristics essential to an effective
candidate vaccine antigen. Sample lipooligosaccharides (LOS), was prepared
by a modification of the hot phenol-water method from which de-O-acetylated
LOS and oligosaccharide (OS) components were analyzed by ES-MS-CID-MS and
ES-MSnin a triple quadrupole and an ion trap mass spectrometer,
respectively. Previously documented natural heterogeneity was apparent from
both LOS and OS preparations which was admixed with fragments induced by
hydrazine and mild acid treatment. Natural heterogeneity was limited to
phosphorylation and antenni extensions to the alpha-chain. Mild acid
hydrolysis to release OS also hydrolyzed the beta(1-->6) glycosidic
linkage of lipid A. OS structures were determined by collisional and
resonance excitation combined with MS and multistep MSn which provided
sequence information from both neutral loss, and nonreducing terminal
fragments. A comparison of OS structures, with earlier knowledge of MAb
binding, enzyme treatment, and partial acid hydrolysis indicates a generic
overlapping domain for 2C7 binding. Reoccurring structural features include
a Hepalpha(1-->3)Hepbeta(1-->5)KDO trisaccharide core branched on the
nonreducing terminus (Hep-2) with an alpha(1-->2) linked GlcNAc
(gamma-chain), and an alpha-linked lactose (beta-chain) residue. From the
central heptose (Hep-1), a beta(1-->4) linked lactose (alpha-chain),
moiety is required although extensions to this residue appear unnecessary.
相似文献
10.
Assessing and reporting heterogeneity in treatment effects in clinical trials: a proposal 总被引:1,自引:0,他引:1
David M Kent Peter M Rothwell John PA Ioannidis Doug G Altman Rodney A Hayward 《Trials》2010,11(1):1-11