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71.
F. A. Popp W. Nagl K. H. Li W. Scholz O. Weingärtner R. Wolf 《Cell biochemistry and biophysics》1984,6(1):33-52
The phenomenon of ultraweak photon emission from living systems was further investigated in order to elucidate the physical
properties of this radiation and its possible source. We obtained evidence that the light has a high degree of coherence because
of (1) its photon count statistics, (2) its spectral distribution, (3) its decay behavior after exposure to light illumination,
and (4) its transparency through optically thick materials. Moroever, DNA is apparently at least an important source, since
conformational changes induced with ethidium bromide in vivo are clearly reflected by changes of the photon emission of cells.
The physical properties of the radiation are described, taking DNA as an exciplex laser system, where a stable state can be
reached far from thermal equilibrium at threshold. 相似文献
72.
73.
The uncoupling-like effect of fatty acids [ Scholz , R., Schwabe , U., and Soboll , S. (1984) Eur. J. Biochem. 141, 223-230] was further substantiated in experiments with perfused rat livers by two ways: firstly the kinetics of changes in metabolic rates (oxygen consumption, ketogenesis, fatty acid oxidation) were analysed; secondly subcellular contents of adenine nucleotides and pH gradients across the mitochondrial membrane were determined following fractionation of freeze-fixed and dried tissues in non-aqueous solvents. The following results were obtained. The relaxation kinetics of the increase in oxygen consumption following fatty acid infusion revealed two components, a rapid one with a half-time around 10 s and a slow one with a half-time of more than 100 s. The rapid component was similar to the kinetics of fatty acid oxidation (ketogenesis and 14CO2 production from labelled fatty acids) whereas the half-time of the slow component was in the range of half-times observed with the increase in oxygen consumption following addition of carbonylcyanide p-trifluoromethoxyphenylhydrazone. In the presence of fatty acids, the cytosolic ATP concentrations and ATP/ADP ratios decreased, whereas the corresponding parameters for the mitochondrial space were either increased (oleate) or decreased (octanoate). The effects of oleate were dependent on the albumin concentrations in the perfusate. The normally large difference between cytosolic and mitochondrial ATP/ADP ratios became smaller. Similar observations were obtained with uncoupling agents. The pH gradient across the mitochondrial membrane as calculated from the subcellular distribution of 5,5 dimethyl[2-14C]oxazolidine-2,4-dione was inversed following the addition of both carbonylcyanide p-trifluoromethoxyphenylhydrazone and fatty acids, i.e. the mitochondrial matrix became more acidic than the cytosol. The pH gradient was not affected when oleate was added in the presence of high albumin concentrations. The data support the hypothesis that the increase in hepatic oxygen consumption due to octanoate or oleate is, in part, caused by a mechanism similar to uncoupling of oxidative phosphorylation. This mechanism seems not to be an artifact of isolated systems; it may be of physiological importance for processes in which reducing equivalents are removed independently of the ATP demand of the hepatocyte. 相似文献
74.
A flexing and gliding green sulfur bacterium has been isolated from marine sources off the North East coast of the USA. Chloroherpeton thalassium is an obligate phototroph, and requires CO2 and S2- for growth; some organic acids can contribute to cell carbon, and N2 may be fixed. The cells contain typical chlorosomes, and gas vesicles may be present. Bacteriochlorophyll c is the main light harvesting pigment, and a small quantity of bacteriochlorophyll a is also present. Over 80% of the carotenoid is -carotene. DNA base composition of the isolates ranges from 45.0–48.2 mol% G+C.In memory of R. Y. Stanier 相似文献
75.
Glucuronic acid conjugates of bilirubin-IXα in normal bile compared with post-obstructive bile. Transformation of the 1-O-acylglucuronide into 2-, 3-, and 4-O-acylglucuronides 总被引:7,自引:2,他引:5 下载免费PDF全文
Frans Compernolle Gustaaf P. Van Hees Norbert Blanckaert Karel P. M. Heirwegh 《The Biochemical journal》1978,171(1):185-201
Structures have been determined for bilirubin-IXalpha conjugates in freshly collected bile of normal rats, dogs and man and in post-obstructive bile of man and rats. The originally secreted conjugate has been characterized as azopigment (I), i.e. a 1-O-acyl-beta-d-glucopyranuronic acid glycoside. Conversion of the acetylated methyl ester of azopigment (I) into methyl 2,3,4-tri-O-acetyl-1-bromo-1-deoxy-beta-d-glucopyranuronate (V) indicates the pyranose ring structure for the carbohydrate and a C-1 attachment for the bilirubin-IXalpha acyl group. Alternative procedures for deconjugation of azopigment (I) and its derivatives are also described. In post-obstructive bile, the 1-O-acylglucuronide is converted into 2-, 3- and 4-O-acylglucuronides via sequential intramolecular migrations of the bilirubin acyl group. The following approach was utilized. (1) The tetrapyrrole conjugates were cleaved to dipyrrolic aniline and ethyl anthranilate azopigments, and the azopigments were separated as the acids or methyl esters. (2) The isomeric methyl esters were characterized by mass spectral analysis of the acetates and silyl ethers. (3) The free glycosidic function was demonstrated by 1-oxime and 1-methoxime derivative formation. (4) The position of the dipyrrolic O-acyl group was determined for the methyl esters by protecting the free hydroxyl groups of the glucuronic acid moieties as the acetals formed with ethyl vinyl ether and by further conversion of the carbohydrates into partially methylated alditol acetates. These were analysed by using g.l.c.-mass spectrometry. The relevance of the present results with regard to previous reports on disaccharidic conjugates is discussed. Details of procedures for the formation of chemical derivatives for g.l.c. and mass spectrometry have been deposited as Supplementary Publication SUP 50081 (15 pages) at the British Library Lending Division, Boston Spa, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1978), 169, 5. 相似文献
76.
Limited chymotryptic cleavage of soluble chicken gizzard desmin protofilaments allows the characterization of three structurally distinct domains. A surface-exposed very basic amino-terminal region (the headpiece) with an amino acid sequence excluding a-helical organization (7.5 kd) is separated from the perhaps globular carboxy-terminal 48 residues (the tailpiece) by a distinctly different middle domain of approximately 330 residues. This 38 kd domain is very rich in α-helix (at least 83%), and electron microscopy reveals a thin rod with a length of 500 ± 50 Å. Amino acid sequence data also show that the rod domain is interrupted by a nonhelical portion. An a-helical array is able to form a coiled-coil spanning the carboxy-terminal half of the 38 kd domain. The a-type diffraction pattern of 10 nm filaments arises from a coiled-coil conformation displayed through most but not all of the middle domain of the protofilaments. 相似文献
77.
Dr. Karen S. Zier Bernd Gänsbacher Sigfried Scholz Ekkehard D. Albert 《Immunogenetics》1980,10(5):513-520
The primed lymphocyte typing test (PLT) is used to detect the gene products of theHLA-D region which are responsible for secondary restimulation of cells primed in MLC. Alternatively, products of theHLA-D region may be detected serologically using antisera directed against a subpopulation of lymphocytes; these are the so-called DRw determinants. The PLT was used to see if it were possible to detect heterogeneity within a given serologically defined group using a cellular test. As priming combinations, we used family members identical for one haplotype and differing in theHLA-A, B andC regions, but not theD region of the second haplotype. Our results indicated that it was possible to prime against this second haplotype and that the segregation of the difference followedHLA. Therefore, using a cellular test it was possible to detect differences among cells belonging to a given DRw group. This suggests that PLT can be a useful tool to identify those serological groups which are composed of heterogenous determinants. In addition, it points out the problem in using any one test to establish identity of theHLA-D region, especially for clinical purposes. 相似文献
78.
Summary Light and dark adaptations were studied in the eye of Squilla mantis. Light adaptation is characterized by (1) a proximal shift of the distal pigment sheath (DPS) surrounding the proximal portion of the crystalline cone above its zone of contact with the rhabdom; (2) flattening of the distal pigment sheath; (3) lengthening of the crystalline cone correlated with shortening of the rhabdom; (4) a migration of screening pigment granules in retinula cells in the protoplasmic bridges crossing the perirhabdomal space. In animals kept in constant darkness, longitudinal displacements of the distal pigment sheath were found to be subject to a circadian rhythm characterized by a maximal light adaptation state at about 5 p.m. and a minimal one at 5 a.m. Screening pigment granule translocation in retinula cells does not show such rhythmic activity.Abbreviations a, b
maximal incidence angles in L.A., and D.A., respectively
- Cc
crystalline cone
- Dps
distal pigment sheath
- I
extreme incident light beam
- Prs
perirhabdomal space
- Rh
rhabdom
- Rp
reflecting pigment
This research has been supported by grant 3.012-76 of the Swiss National Science Foundation 相似文献
79.
Three strains (2ac9, 3ac10 and 4ac11) of oval to rodshaped, Gram negative, nonsporing sulfate-reducing bacteria were isolated from brackish water and marine mud samples with acetate as sole electron donor. All three strains grew in simple defined media supplemented with biotin and 4-aminobenzoic acid as growth factors. Acetate was the only electron donor utilized by strain 2ac9, while the other two strains used in addition ethanol and/or lactate. Sulfate served as electron acceptor and was reduced to H2S. Complete oxidation of acetate to CO2 was shown by stoichiometric measurements with strain 2ac9 in batch cultures using sulfate, sulfite or thiosulfate as electron acceptors. With sulfate an average growth yield of 4.8 g cell dry weight was obtained per mol of acetate oxidized; with sulfite or thiosulfate the growth yield on acetate was about twice as high. None of the strains contained desulfoviridin. In strain 2ac9 cytochromes of the b- and c-type were detected. Strain 2ac9 is described as type strain of the new species and genus, Desulfobacter postgatei. 相似文献
80.
Archives of Microbiology - A new strictly anaerobic, polarly flagellated, sporing, acetate-oxidizing, sulfate-reducing bacterium was isolated from anaerobic fresh or sea water mud samples. The... 相似文献