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11.
Jaime F. Angulo Jaime Schwencke Patrice L. Moreau Ethel Moustacchi Raymond Devoret 《Molecular & general genetics : MGG》1985,201(1):20-24
Summary In Saccharomyces cerevisiae, a protein was recognized by polyclonal antibodies raised against homogeneous Escherichia coli K12 RecA protein. The cellular level of the yeast protein called RecAsc (molecular weight 44 kDa, pI 6.3), was transiently enhanced after UV irradiation. Protease inhibitors were required to minimize degradation of the RecAsc protein during cell lysis. The RecAsc protein exhibited similar basal levels and similar kinetics of increase after UV irradiation in DNA-repair proficient (RAD
+) strains carrying mitochondrial DNA or not (rho
0). This was also true for the following DNA-repair deficient (rad
-) strains: rad2-6 rad6-1 rad52-1, a triple mutant blocked in three major repair pathways; rad6-, a mutant containing an integrative deletion in a gene playing a central role in mutagenesis; pso2-1, a mutant that exhibits a reduced rate of mutagenesis and recombination after exposure to DNA cross-linking agents. 相似文献
12.
T Patrice B Dreno J Weber L Le Bodic H Barriere 《Plastic and reconstructive surgery》1985,76(4):554-557
The argon laser, which has been proven both useful and safe for port-wine stain therapy, interacts with the hemoglobin of the vessels. In a percentage of cases, this treatment is still inefficient, and there is a lack of correlation between these bad results and clinical or histologic criteria. Thermography, which explores the vascularization of the port-wine stain, leads us to consider port-wine stains from a physical point of view. This very simple test shows no correlation with the clinical parameters of port-wine stain but is closely related to the results obtained with laser therapy. It seems to be a good criterion to estimate the argon laser treatment prognosis. 相似文献
13.
Optimum growth conditions for the fermentation of non-concentrated whey permeate by Kluyveromyces fragilis NRRL 665 have been defined. Use of 3.75 g yeast extract l?1, a growth temperature of 38°C and a pH of 4.0 allowed a maximum productivity of 5.23 g ethanol l?1 h?1 in continuous culture with a yield 91% of theoretical. Complete batch fermentation of permeate with 100 g lactose l?1 was possible with a maximum specific growth rate of 0.276 h?1 without any change in ethanol yield. Fermentation of concentrated permeate resulted, however, in a general decrease of specific substrate consumption rate, demonstrated by the inability to completely convert an initial 90 or 150 g lactose l?1 in continuous culture, even at dilution rates as low as 0.05 and 0.08 h?1, respectively. The decrease could be related to substrate inhibition, to an increase in osmotic pressure caused by lactose and salts, and to ethanol inhibition of both alcohol and biomass yield. The decrease in specific productivity could be counterbalanced by use of high cell density cultures, obtained by cell recycle of K. fragilis. Fermentation of a non-concentrated permeáte at a dilution rate of 1 h?1 resulted in a productivity of 22 g l?1 h?1 at 22 g ethanol l?1. Cell recycle using flocculating Kluyveromyces lactis NCYC 571 was also tested. With this strain a productivity of 9.3 g l?1 h?1 at 45 g product l?1 was attained at a dilution rate of 0.2 h?1, with an initial lactose concentration of 95 g l?1. 相似文献
14.
Teresa de Sa E Melo Patrice Morlière Sonia Goldstein René Santus Louis Dubertret Dominique Lagrange 《Biochemical and biophysical research communications》1984,120(2):670-676
5-methoxypsoralen (5-MOP) binds to human serum low density lipoproteins (LDL) according to a two-step process. Scatchard analysis of the first step yields K = 1.4 × 105 M?1 and 4 binding sites. It involves the LDL apoprotein. The second step corresponds to a solubilization, in the lipidic core, of ? 45 molecules of 5MOP per LDL molecule. It is accompanied by a large blue shift of the 5MOP fluorescence. The ability of LDL to bind 5MOP and to carry it into various cells may explain some biological effects sometimes encountered during PUVA therapy. 相似文献
15.
Cerebroside and Sulfatide Biosynthesis in the Brain of Snell Dwarf Mouse: Effects of Thyroxine and Growth Hormone in the Early Postnatal Period 总被引:1,自引:1,他引:0
Snell dwarf mice (dw/dw) and normal mice (+/?) were injected with thyroxine (T4) (1 μg/animal, four injections) and growth hormone (GH) (20 μg/animal, four injections) from the 5th to the 15th day of life. In the untreated dw/dw mouse brain, the specific activities of UDP-galactose:ceramide galactosyltransferase (CGalT), PAPS:cerebroside sulfotransferase (CST), and 2′,3′-cyclic nucleotide 3′-phosphohydrolase (CNP) were decreased by 28, 25, and 37%, respectively, compared with the control untreated +/? mice. The major effect of T4 was an increase of the brain CNP in the +/? mice (+40%) and dw/dw mice (+111%). The treatment with T4 also brought to normal the level of CGalT in dw/dw brain; a somewhat less marked effect on CST was observed. The treatment with GH had a great stimulatory effect on CNP: the specific activity of this enzyme increased by 40 and 69% in +/? and dw/dw mouse brain, respectively. On the contrary, no effect of GH on the CGalT activity was observe in this study. Our results suggest that T4 and GH may have both independent and complementary actions on the myelin-associated enzymes during the early postnatal period of brain development. 相似文献
16.
Jérôme Etienne Guy Gerbaud Patrice Courvalin Jean Fleurette 《FEMS microbiology letters》1989,61(1-2):133-138
Staphylococcus epidermidis strain BM2641, isolated from a patient, was resistant to penicillin G, methicillin, aminoglycosides, chloramphenicol, macrolide, lincosamide and streptogramin B-type (MLS) antibiotics, and to high levels of fosmycin. Resistance to forsfomycin and/or to MLS was lost at low frequencies either spontaneously or after curing with novobiocin. The plasmid DNA from BM2641 and its cured derivatives was purified, analyzed by agarose gel electrophoresis and transferred to a nitrocellulose sheet. Comparative analysis of the resistance phenotypes with the plasmid content of the strains indicated that fosfomycin and MLS resistance were encoded by plasmids pIP1842 (2.5 kb) and pIP1843 (2.6 kb), respectively. Southern hybridization with a probe specific for gene fosA of Serratia marcescens showed that the fosfomycin resistance determinant in Staphylococcus is not homologous to that of Gram-negative bacteria. 相似文献
17.
(Z)-4',5'-Didehydro-5'-deoxy-5'-fluoroadenosine (I), 5'-deoxy-5'-difluoroadenosine (II), and 4',5'-didehydro-5'-deoxy-5'-fluoroarabinosyl-adenosine (III) are inhibitors of rat liver S-adenosyl-L-homocysteine hydrolase. Compounds I and II are time-dependent and irreversible inhibitors of the enzyme. Both I and II are oxidized by E.NAD to produce E.NADH, and fluoride anion is formed in the inactivation reaction (0.7 to 1.0 mole fluoride/mole of enzyme subunit, and 1.7 moles fluoride/mole of enzyme subunit from I and II, respectively). The enzyme is stoichiometrically labeled with [8-3H]-I, but the label is lost upon denaturation of the protein either with or without treatment of the labeled complex with sodium borohydride. The compound III, the arabino derivative of I, is a competitive inhibitor of the enzyme. The mechanism of the inhibition of S-adenosyl-L-homocysteine hydrolase by these inhibitors is discussed. 相似文献
18.
Stefan Evers Barbara Casadewall Murielle Charles Sylvie Dutka-Malen Marc Galimand Patrice Courvalin 《Journal of molecular evolution》1996,42(6):706-712
Thed-alanine:d-alanine-ligase-related enzymes can have three preferential substrate specificities. Usually, these enzymes synthesized-alanyl-d-alanine. In vancomycin-resistant Gram-positive bacteria, structurally related enzymes synthesized-alanyl-d-lactate or Dalanyl-d-serine. The sequence of internal fragments of eight structurald-alanine:d-alanine ligase genes from enterococci has been determined. Alignment of the deduced amino acid sequences with those of other
related enzymes from Gram-negative and Gram-positive bacteria revealed the presence of four distinct sequence patterns in
the putative substrate-binding sites, each correlating with specificity to a particular substrate (d-alanine:d-lactate ligases exhibited two patterns). Phylogenetic analysis showed different clusters. The enterococcal subtree was largely
superimposable on that derived from 16S rRNA sequences. In lactic acid bacteria, structural divergence due to differences
in substrate specificity was observed. Glycopeptide resistance proteins VanA and VanB, the VanC-type ligases, and Dd1A and
DdlB from enteric bacteria andHaemophilus influenzae constituted separate clusters.
Correspondence to: P. Courvalin 相似文献
19.
Hanne Gahéry-Ségard Evelyne Jouvin-Marche Adrien Six Carine Gris-Liebe Marie Malissen Bernard Malissen Pierre-André Cazenave Patrice N. Marche 《Immunogenetics》1996,44(4):298-305
The number of mouse Tcra-V gene segments varies from one individual to another and is estimated to be about 100. Southern blot analysis revealed that
most of the Tcra-V are organized in clusters composed of copies of Tcra-V belonging to different subfamilies. We analyzed in detail a Tcra-V subfamily and looked for new Tcra-V in order to improve the knowledge of the mouse Tcra locus organization. A series of genomic clones derived from the B10.A mouse strain enclosing these clusters was used to determined
the structure of all the Tcra-V2. We were able to identify ten Tcra-V2. This study showed that the Tcra-V2 can be organized into three structural subgroups. The distribution of the genes along the Tcra locus, plus their structural organization, indicates that successive duplications occurred during the processes of expansion
and contraction of the Tcra-V gene subfamilies. Several Tcra-V2 are also identical, indicating recent duplications. The most divergent Tcra-V2 differ by 7.4% nucleotides, leading to 5.2% differences in amino acid contents.
Received: 8 August 1995 / Revised: 24 April 1996 相似文献
20.
Mismatch Repair Genes on Chromosomes 2p and 3p Account for a Major Share of Hereditary Nonpolyposis Colorectal Cancer Families Evaluable by Linkage 总被引:17,自引:1,他引:16
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Minna Nystrm-Lahti Ramon Parsons Pertti Sistonen Lea Pylkknen Lauri A. Aaltonen Fredrick S. Leach Stanley R. Hamilton Patrice Watson Earlene Bronson Ramon Fusaro Jennifer Cavalieri Jane Lynch Stephen Lanspa Tom Smyrk Patrick Lynch Thomas Drouhard Kenneth W. Kinzler Bert Vogelstein Henry T. Lynch Albert de la Chapelle Pivi Peltomki 《American journal of human genetics》1994,55(4):659-665
Two susceptibility loci for hereditary nonpolyposis colo-rectal cancer (HNPCC) have been identified, and each contains a mismatch repair gene: MSH2 on chromosome 2p and MLH1 on chromosome 3p. We studied the involvement of these loci in 13 large HNPCC kindreds originating from three different continents. Six families showed close linkage to the 2p locus, and a heritable mutation of the MSH2 gene was subsequently found in four. The 2p-linked kindreds included a family characterized by the lack of extracolonic manifestations (Lynch I syndrome), as well as two families with cutaneous manifestations typical of the Muir-Torre syndrome. Four families showed evidence for linkage to the 3p locus, and a heritable mutation of the MLH1 gene was later detected in three. One 3p-linked kindred was of Amerindian origin. Of the remaining three families studied for linkage, one showed lod scores compatible with exclusion of both MSH2 and MLH1, while lod scores obtained in the other two families suggested exclusion of one HNPCC locus (MSH2 or MLH1) but were uninformative for markers flanking the other locus. Our results suggest that mismatch repair genes on 2p and 3p account for a major share of HNPCC in kindreds that can be evaluated by linkage analysis. 相似文献