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981.
982.
983.
K Murakami 《Biophysical chemistry》1991,41(3):253-261
The binding of tri- and tetra-anionic azo dyes (Amaranth, Ponceau 4R, and Ponceau 6R) to bovine serum albumin (BSA) at pH = 7.0 and 25 degrees C has been studied by equilibrium dialysis, spectrophotometry, and by stopped-flow and temperature-jump methods. Equilibrium dialysis revealed that BSA has one primary binding site and about two secondary sites for each dye. The values of the binding constant for the primary site show that the stability of the complex at the primary site progressively increases with an increase in the number and the density of anionic charges on ligand. Kinetic data have been found to be consistent with a scheme in which a rapid bimolecular binding is followed by two isomerizations of the complex (in the case of Amaranth) or by one isomerization (in the cases of Ponceau 4R and Ponceau 6R). Equilibrium and rate constants for each step of the scheme were determined. From the results it was found that the increment of the number and the density of anionic charges on ligand accelerates the forward process of the final isomerization step but retards the backward one of it, resulting in the enhancement of the stability of the complex at the primary site. On the basis of these results and the structure of the ligands, the detailed binding mechanism has been discussed in the light of the electrostatic interaction between the ligands and the binding site on BSA. 相似文献
984.
985.
The antigen-antibody interaction occurring previous to the triggering of the immunological response is analyzed as a relational process in terms of lattices. Accordingly, this process is expressed as a lattice belonging to a pseudo-Boolean algebraic variety. The Heyting arrow operation, which appears in this kind of algebra, is used to analyze behaviors between non-comparable biological states expressed by the lattice. The resulting states coming from the arrows are connected with the influence of increasing and decreasing energies involved in the linking process. 相似文献
986.
The effects of β-endorphin under the conditions of naloxone hydrochloride blockade of opiate receptors, as well as the effects of the selective agonists of μ-and δ-receptors DAGO and DADLE and the effects of melanocyte-potentiating factor (MPF), on the in vitro proliferative response of lymphocytes were studied. The dose-effect dependence indicated stimulating effects of β-endorphin, DAGO, and DADLE on the proliferative response in the presence of phytohemagglutinin (PHA). The tetrapeptide MPF, which is the C-terminal sequence of β-endorphin, had almost no effect on the proliferative activity of lymphocytes. β-Endorphin, naloxone, and the μ-and δ-receptor selective agonists enhanced the proliferative response of lymphocytes in an unfractionated cell culture, whereas β-endorphin, naloxone, and DAGO suppressed the proliferative activity of lymphocytes in the mononuclear fraction purified of monocytes. In both cases, the naloxone blockade of opiate receptors enhanced rather than eliminated the β-endorphin effect. 相似文献
987.
988.
Summary A child with cri-du-chat syndrome, 46,XY,5p-, was born to a mother who had two normal children and two abortuses. The mother was shown to carry a balanced translocation. Giemsa and fluorescent banding demonstrate the exact location of the translocated segment. The deleted short arm of chromosome number 5 was shown to be attached to the long arm of chromosome number 11.
We are indeed indebted to Dr. G. R. Hennigar for facilities and Dr. C. D. Barnett for financial assistance. 相似文献
Zusammenfassung Ein Kind mit Cri-du-chat Syndrom und Karyotyp 46,XY,5p- wurde von einer Mutter geboren, die zuvor zwei gesunde Kinder und zwei Aborte gehabt hatte. Bei der Mutter wurde eine balancierte Translokation nachgewiesen; Chiemsa- und Fluorescens-Bandenmuster zeigten die genaue Lokalisation des translozierten Segmentes: Der deletierte kurze Arm des Chromosoms Nr.5 war an den langen Arm vom Chromosom Nr. 11 angeheftet.
We are indeed indebted to Dr. G. R. Hennigar for facilities and Dr. C. D. Barnett for financial assistance. 相似文献
989.
We have earlier demonstrated that a mixed population of immunologically specific killer cells, including cytotoxic T lymphocytes, non-T (“B”) lymphocytes and monocytes, infiltrate “sponge matrix” allografts at the peak of rejection on Day 8 after transplantation. We have now performed a sequential study covering both early and late stages of the rejection response. We demonstrate that the early infiltrating killer cells are sensitive to anti-Ø and anti-T cell serum plus complement treatment but the late killer cells are not. This finding indicates that the first cytotoxic host cells infiltrating the allograft are predominantly T lymphocytes, whereas as the rejection process proceeds also cytotoxic non-T (“B”) lymphocytes and monocytes are recruited to the site of inflammation. 相似文献
990.