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101.
Summary Serotonin-like immunoreactivity was investigated in the pineal complex of the golden hamster by use of the indirect immunohistochemical technique. The superficial and deep portions of the pineal gland, and also the pineal stalk exhibited an intense cellular immunoreaction for serotonin. In addition, perivascular serotonin-immunoreactive nerve fibers were observed. Some serotonin-immunoreactive processes of the pinealocytes terminated on the surface of the ventricular lumen in the pineal and suprapineal recesses, indicating a receptive or secretory function of these cells. Several serotonin-immunoreactive processes connected the deep pineal with the habenular area. One week after bilateral removal of both superior cervical ganglia the serotonin immunoreaction of the entire pineal complex was greatly decreased. However, some cells in the pineal complex, of which several exhibited a neuron-like morphology, remained intensively stained after ganglionectomy. This indicates that the indoleamine content of some cells in the pineal complex of the golden hamster is independent of the sympathetic innervation.Supported by a Grant from the Italian Society for Veterinary Sciences 相似文献
102.
Recognition of 5' splice points by group I and group II self-splicing introns involves the interaction of exon sequences--directly preceding the 5' splice site--with intronic sequence elements. We show here that the exon binding sequences (EBS) of group II intron aI5c can accept various substitutes of the authentic intron binding sites (IBS) provided in cis or in trans. The efficiency of cleavages at these cryptic 5' splice sites was enhanced by deletion of the authentic IBS2 element. All cryptic 5' cleavage sites studied here were preceded by an IBS1 like sequence; indicating that the IBS1/EBS1 pairing alone is sufficient for proper 5' splice site selection by the intronic EBS element. The results are discussed in terms of minimal requirements for 5' cleavages and position effects of IBS sites relative to the intron. 相似文献
103.
Histone genes of Volvox carteri: DNA sequence and organization of two H3-H4 gene loci. 总被引:1,自引:1,他引:0
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Two Volvox genomic clones each containing a pair of histone H3-H4 genes were sequenced. In both loci the H3 and H4 genes show outwardly divergent polarity, their coding regions being separated by short intercistronic sequences containing TATA boxes and a conserved 14-bp element. The 3' untranslated regions contain a characteristic motif with hyphenated dyad symmetry otherwise only found associated with animal histone genes. Derived amino acid sequences of histones H3 and H4 are highly conserved and identical between the two sets. The Volvox H3 genes both contain one intron whose relative position is shifted by one basepair. Sequence comparisons led to a new interpretation of intron sliding. The Volvox H3 gene structure combines the exon-intron organization of fungal H3 and vertebrate H3.3 genes with a termination signal typical for animal H3.1 genes. These features are discussed in view of histone gene evolution. 相似文献
104.
E. Tichatschek C. C. Zielinski Ch. Müller P. Sevelda E. Kubista K. Czerwenka J. Spona H. Wolf M. M. Eibl 《Cancer immunology, immunotherapy : CII》1988,27(3):278-282
Summary Unstimulated IFN- and IL2-stimulated (NK) cell activities were investigated in patients with breast cancer who had received either local radiotherapy alone or adjuvant chemotherapeutic treatment with CMF combined with radiotherapy 12 to 18 months previously. When tested against the primarily NK-sensitive K562 cell line, patients who had received adjuvant chemotherapeutic treatment with CMF were shown to have a significantly decreased unstimulated and IFN-stimulated NK cell activity, as compared to both patients after radiotherapy only (P<0.002) and P<0.005, respectively) and healthy control persons (P<0.05). The former group of patients also had a significantly decreased IFN-stimulated NK cell activity, when tested against the primarily NK-insensitive Chang hepatoma cell line, as compared to patients after radiotherapy only (P<0.005) and healthy controls (P<0.05). Moreover, patients after radiotherapy only proved to have a significantly increased unstimulated (P<0.01) and IFN-stimulated NK cell activity (K562: P<0.05; Chang hepatoma cell line: P<0.05), as compared to healthy control individuals. In contrast, no difference in IL2-stimulated NK cell activity was detected. The investigation for the expression of CD3 and/or Leu 19 antigens as phenotypic markers of cells with non-MHC restricted cytotoxicity showed a significantly lower percentage of cells with the CD3+ phenotype in patients with breast cancer, irrespective of the chosen post-operative treatment, as compared to healthy controls (P<0.01). Finally, patients with breast cancer who had received radiotherapy only had a significant trend towards an increased percentage of CD3+/Leu 19+ PMNC, as compared to both patients after CMF treatment (P<0.05) and healthy controls (P<0.025). We conclude that patients with breast cancer vary on a long-term basis in their NK activity and in the phenotype of their PMNC depending on their post-operative adjuvant management.Abbreviations NK
natural killer cells
- IFN
interferon
- IL 2
interleukin 2
- CMF
cyclophosphamide, methotrexate, fluorouracil
- ER
oestrogen receptor
- PMNC
peripheral blood mononuclear cells
- MHC
major histocompatibility complex
- CTL
cytotoxic T lymphocytes 相似文献
105.
The structure of crystalline bacterial surface layers 总被引:25,自引:0,他引:25
106.
The homeotic gene Ultrabithorax (Ubx) is expressed in specific parts of Drosophila embryos: in a single metamer in the visceral mesoderm and forming a complex pattern limited to a broad domain in the ectoderm and in the somatic mesoderm. Here we use a linked beta-galactosidase gene to identify cis-acting regulatory sequences. In the visceral mesoderm, correct expression of Ubx depends on localized upstream sequences. In the ectoderm, all galactosidase-positive transformants show the same characteristic pattern. The repeated elements of this basal pattern appear to be a sub-pattern of engrailed (en) expression; they depend on en function as well as on sequences in the Ubx RNA leader. We use a mutant (Haltere-mimic) to show that sequences that normally restrict segmental expression of Ubx in the ectoderm are located downstream from the RNA leader. 相似文献
107.
Jürgen Thiele Rudolf Müller Franz Lingens 《Applied microbiology and biotechnology》1988,27(5-6):577-580
Summary 4-Chlorobenzoate dehalogenase from Pseudomonas sp. CBS3 showed dehalogenating activity in various organic solvents. In alcohols like methanol (150%) or ethanol (120%) higher activities than in water (100%) were obtained. In apolar solvents like petroleum ether (5%) and nhexane (5%) only trace activities were observed. The solvents did not increase the stability of the enzyme. 4-Chlorobenzoic acid methylester, a substance not soluble in water, was not dehalogenated in organic solvents. 相似文献
108.
Formation of double-walled microtubules and multilayered tubulin sheets by basic proteins 总被引:1,自引:0,他引:1
E Unger K J B?hm H Müller H Grossman H Fenske W Vater 《European journal of cell biology》1988,46(1):98-104
Some basic proteins enable microtubule protein to form special assembly products in vitro, known as double-walled microtubules. Using histones (H1, core histones) as well as the human encephalitogenic protein to induce the formation of double-walled microtubules, we made the following electron microscopic observations: (1) Double-walled microtubules consist of an "inner" microtubule which is covered by electron-dense material, apparently formed from the basic protein, and by a second tubulin wall. (2) The tubulin of the second wall seems to be arranged as protofilaments, surrounding the inner microtubule in a helical or ring-like manner. (3) The surface of double-walled microtubules lacks the projections of microtubule-associated proteins, usually found on microtubules. (4) In the case of protofilament ribbons (incomplete microtubules), H1 binds exclusively to their convex sides that correspond to the surface of microtubules. Zn2+-induced tubulin sheets, consisting in contrast to microtubules of alternately arranged protofilaments, are covered by H1 on both surfaces. Furthermore, multilayered sheet aggregates appeared. The results indicate that the basic proteins used interact only with that protofilament side which represents the microtubule surface. In accordance with this general principle, models on the structure of double-walled microtubules and multilayered tubulin sheets were derived. 相似文献
109.
Enzymatic dehalogenation of 4-chlorobenzoate by extracts from Arthrobacter sp. SU DSM 20407 总被引:6,自引:0,他引:6
In extracts from Arthrobacter sp. SU DSM 20407 an enzyme was detectable, that converted 4-chlorobenzoate into 4-hydroxybenzoate. This conversion was also observed when no oxygen was present in the reaction mixture. Boiling for 5 min destroyed the enzyme activity. 4-Bromo- and 4-iodobenzoate were substrates for the enzyme too, but not 4-fluorobenzoate, 4-chlorophenylacetate and 4-chlorocinnamic acid. The enzyme showed optimum activity at 16 degrees C and at pH 7-7.5. The specific activity in the extracts varied between 0.5 and 5 mU/mg of protein. Zn2+ and Cu2+ inhibited the enzyme, while H2O2 slightly activated. In contrast to all other 4-chlorobenzoate dehalogenases described before the enzyme was not inhibited by EDTA, nor was it activated by Mn2+. Other divalent ions also had no effect. The molecular mass of the enzyme was 45,000 +/- 5,000 Da as judged by gel-filtration. 相似文献
110.
Caudoxirene, the spermatozoid-releasing and attracting factor in the marine brown alga Perithalia caudata (Phaeophyceae, Sporochnales) 总被引:2,自引:0,他引:2
Caudoxirene (cis-3-(1,2-trans-epoxy-but-3-enyl)-4-vinyl-cyclopentene) is a new gamete releasing factor from Perithalia caudata (Sporochnales). Its threshold concentration is found at 30 pmol for gamete release. Multifidene, viridiene and a Z-isomer of caudoxirene were identified as by-products or trace constituents. 相似文献