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91.
On the isolation of TI-plasmid from Agrobacterium tumefaciens. 总被引:3,自引:0,他引:3
A M Ledeboer A J Krol J J Dons F Spier R A Schilperoort I Zaenen N van Larebeke J Schell 《Nucleic acids research》1976,3(2):449-463
An efficient lysis method for Agrobacterium cells was developed, which allows a reproducible isolation of the tumor inducing (TI)-plasmid. The lysis method is based on the sensitivity of this bacterium to incubation with lysozyme, n-dodecylamine,EDTA, followed by Sarkosyl, after growth in the presence of carbenicillin. We also present a procedure for the isolation of the TI-plasmid on a large scale, that might be used for the mass isolation of other large plasmids which like the TI-plasmid, can not be cleared with earlier described procedures. The purity of the plasmid preparations was determined with DNA renaturation kinetics, which method has the advantage that the plasmid need not to be in the supercoiled or open circular form. 相似文献
92.
93.
Samaj Jozef; Braun Markus; Baluska Frantisek; Ensikat Hans-Jurgen; Tsumuraya Yoichi; Volkmann Dieter 《Plant & cell physiology》1999,40(8):874-883
Arabinogalactan-proteins (AGPs) are often localized at plantsurfaces. However, their function there is unknown. We haveused immunogold/silver and immunofluorescence techniques tostudy the developmental occurrence of an glucuronic acid (GlcA)-containingAGP epitope and ß-(1 相似文献
94.
Supercoiled circular DNA in crown-gall inducing Agrobacterium strains 总被引:57,自引:0,他引:57
95.
This work presents the results of the study of airborne bacteria in a kindergarten in Gliwice, Upper Silesia, Poland. In this study, the samples of bioaerosols were collected using six-stage Andersen cascade impactor (with aerodynamic cutoff diameters 7.0, 4.7, 3.3, 2.1, 1.1, and 0.65 μm). The level of culturable bacterial aerosols indoors was about 3000 CFU m?3—six to eight times higher than outdoors. In the classrooms, respirable bacterial particles, <4.7 µm, contributed up to 85 % of the total number of culturable bacteria, increasing the possible adverse health effects due to their inhalation. The identification of the bacterial species showing the dominance of gram-positive cocci in the indoor environment and non-sporing gram-positive rods in the outdoor air indicates that most of the bacteria present in the studied kindergarten are human origin. Using the obtained data, the nursery school exposure dose (NSED) of bioaerosols was estimated for the children and personnel of this kindergarten (nursery school). The highest value of NSED was obtained for younger children (930 CFU kg?1) compared to older children (about 600 CFU kg?1) and to the kindergarten staff (about 300 CFU kg?1). This result suggests the elevated risk of adverse health effects in younger children exposed to the bioaerosols in the kindergarten, including infections. 相似文献
96.
Markus V. Heppt Thomas K. Eigentler Katharina C. Kähler Rudolf A. Herbst Daniela Göppner Thilo Gambichler Jens Ulrich Edgar Dippel Carmen Loquai Beatrice Schell Bastian Schilling Susanne G. Schäd Erwin S. Schultz Fanny Matheis Julia K. Tietze Carola Berking 《Cancer immunology, immunotherapy : CII》2016,65(8):951-959
97.
98.
Streptomyces coelicolor A3(2) produces several intra and extracellular enzymes with deoxyribonuclease activities. The examined N-terminal amino acid sequence of one of extracellular DNAases (TVTSVNVNGLL) and database search on S. coelicolor genome showed a significant homology to the putative secreted exodeoxyribonuclease. The corresponding gene (exoSc) was amplified, cloned, expressed in Escherichia coli, purified to homogeneity and characterized. Exonuclease recExoSc degraded chromosomal, linear dsDNA with 3'-overhang ends, linear ssDNA and did not digest linear dsDNA with blunt ends, supercoiled plasmid ds nor ssDNA. The substrate specificity of recExoSc was in the order of dsDNA>ssDNA>3'-dAMP. The purified recExoSc was not a metalloprotein and exhibited neither phosphodiesterase nor RNase activity. It acted as 3'-phosphomonoesterase only at 3'-dAMP as a substrate. The optimal temperature for its activity was 57 degrees C in Tris-HCl buffer at optimal pH=7.5 for either ssDNA or dsDNA substrates. It required a divalent cation (Mg(2+), Co(2+), Ca(2+)) and its activity was strongly inhibited in the presence of Zn(2+), Hg(2+), chelating agents or iodoacetate. 相似文献
99.
100.
Summary In this study, immunohistochemistry for neuronal nitric oxide synthase (bNOS-IR), nicotinamide adenine dinucleotide phosphate
diaphorase histochemistry (NADPHd) and nitric oxide synthase radioassay were used to study the occurrence, number and distribution
pattern of nitric oxide synthesizing neurons in the lumbar (L1–L7) and sacral (S1–S3) dorsal root ganglia of the dog. Nitric
oxide synthase immunolabelling was present in a large number of small- (area <1000 μm2) and medium-sized (area 1000–2000 μm2) as well as in a limited number of large-sized (area >2000 μm2) neurons. Although neuronal nitric oxide synthase immunolabelling and histochemical staining provided intense staining of
multiple small- and medium-sized neurons in all lumbar and sacral dorsal root ganglia, immunolabelled or histochemically stained
somata exhibited little topographic distribution in individual dorsal root ganglia. Great heterogeneity was noticed in the
immunolabelling of medium-sized nitric oxide synthase immunopositive neurons ranging from lightly immunolabelled somata to
heavily immunoreactive ones with completely obscured nuclei. Both staining procedures proved to be highly effective in visualizing
intraganglionic fibers of various diameters. In general, the largest fibers revealed at the peripheral end of lumbar and sacral
dorsal root ganglia were larger, 6.49–9.35 μm in diameter, while those running centrally and proceeding into the dorsal roots
were about 30% reduced, ranging between 5.32 and 8.67 μm in diameter. Peripherally, the occurrence of nitric oxide synthase
detected in axonal profiles, and confirmed histochemically, in the specimens of the femoral and sciatic nerves, is the first
indication of the presence of nitric oxide synthase in the peripheral processes of somata located in L4–S2 dorsal root ganglia.
Large and thin central nitric oxide synthase immunoreactive processes of L1–S3 dorsal root ganglion neurons segregate shortly
before entering the spinal cord, the former making a massive medial bundle in the dorsal root accompanied by a slim lateral
bundle penetrating Lissauer's tract. Quantitative assessment of the distribution of bNOS-IR and/or NADPHd-stained neurons
showed a peculiar pattern in relation to spinal levels. Apparent incongruity was found in the total number of NADPHd-stained
versus bNOS-IR neurons, demonstrating a clear prevalence of small bNOS-IR somata in all lumbar ganglia, while medium-sized
NADPHd-stained somata clearly prevailed all along the rostrocaudal axis with a peak in L5 ganglion. While the number of small
bNOS-IR neurons clearly outnumbered NADPHd-stained and NADPHd-unstained somata in S1–S3 ganglia, an inverse relation appeared
comparing the total number of medium-sized NADPHd-stained and NADPHd-unstained somata compared with the number of moderate
and intense bNOS-IR neurons. Densitometry of bNOS-IR and NADPHd-stained neurons in lumbar and sacral ganglia revealed two
distinct subsets of densitometric profiles, one relating to more often found medium-sized bNOS immunolabelled and the other,
characteristic for moderately bNOS immunoreactive somata of the same cell size. Considerable differences in catalytic nitric
oxide synthase activity, determined by conversion of [3H]arginine to [3H]citrulline were obtained in lumbosacral dorsal root ganglia all along the lumbosacral intumescence, the lowest (0.898± 0.2
dpm/min/μg protein) being in the L4 dorsal root ganglion and the highest (4.194± 0.2 dpm/min/μg protein) in the S2 dorsal
root ganglion. 相似文献