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排序方式: 共有421条查询结果,搜索用时 15 毫秒
1.
Cloning and sequencing of the peroxisomal amine oxidase gene from Hansenula polymorpha 总被引:7,自引:0,他引:7
P G Bruinenberg M Evers H R Waterham J Kuipers A C Arnberg G AB 《Biochimica et biophysica acta》1989,1008(2):157-167
We have cloned the AMO gene, encoding the microbody matrix enzyme amine oxidase (EC 1.4.3.6) from the yeast Hansenula polymorpha. The gene was isolated by differential screening of a cDNA library, immunoselection, and subsequent screening of a H. polymorpha genomic library. The nucleotide sequence of a 3.6 kilobase stretch of DNA containing the amine oxidase (AMO) gene was determined. The AMO gene contains an open reading frame of 692 amino acids, with a relative molecular mass of 77,435. The 5' and 3' ends of the gene were mapped and show that the transcribed region measures 2134 nucleotides. The derived amino-acid sequence was confirmed by sequencing an internal proteolytic fragment of the purified protein. Amine oxidase contains the tripeptide sequence Ser-Arg-Leu, located 9 residues from the carboxy terminus, which may represent the topogenic signal for protein import into microbodies. 相似文献
2.
3.
The topogenic signal of the glycosomal (microbody) phosphoglycerate kinase of Crithidia fasciculata resides in a carboxy-terminal extension. 总被引:15,自引:1,他引:14 下载免费PDF全文
To determine how microbody proteins enter microbodies, we have previously compared the genes for the cytosolic and glycosomal (microbody) phosphoglycerate kinases (PGKs) of Trypanosoma brucei and found the microbody enzyme to differ from other PGKs and the cytosolic form in two respects: a high net positive charge and a C-terminal extension of 20 amino acids (Osinga et al., 1985). Here we present the comparison of the genes for the cytosolic and glycosomal PGKs of Crithidia fasciculata, another kinetoplastid organism. The amino acid sequences of the two Crithidia isoenzymes are virtually identical, except for a C-terminal extension of 38 amino acids. We conclude that this extension must direct the glycosomal PGK to the glycosome. The extensions of the Crithidia and Trypanosoma enzymes are both rich in small hydrophobic and hydroxyl amino acids. 相似文献
4.
5.
This paper characterizes the low-affinity ligand binding interactions of a fluorinated volatile anesthetic, isoflurane (CHF2OCHClCF3), with bovine serum albumin (BSA) using 19F-NMR transverse relaxation (T2). 19F-NMR spectra of isoflurane in aqueous BSA reveal a single isoflurane trifluoromethyl resonance, indicative of rapid exchange of isoflurane between protein-bound and aqueous (free) environments. The exchange is slow enough, however, that the chemical shift difference between bound and free isoflurane (delta omega = 0.545 ppm) contributes to the observed isoflurane T2. The contribution of delta omega to T2 can be minimized by shortening the interval between 180 degrees refocusing pulses in the Carr-Purcell-Meiboom-Gill pulse sequence used to monitor T2. Analysis of the dependence of T2 on interpulse interval additionally allows determination of the T2 (6.2 ms) and the average lifetime (tau b = 187 microseconds) of bound isoflurane molecules. By use of a short interpulse interval (less than 100 microseconds), T2 measurements can readily be used to analyze equilibrium binding of isoflurane to BSA. This analysis revealed a discrete saturable binding component with a KD = 1.4 mM that was eliminated either by coincubation with oleic acid (6 mol/mol of BSA) or by conversion of BSA to its "expanded" form by titration to pH 2.5. The binding was independently characterized using a gas chromatographic partition analysis (KD = 1.4 mM, Bmax = 3-4 sites). In summary, this paper describes a method whereby T2 measurements can be used to characterize equilibrium binding of low-affinity ligands to proteins without the confounding contributions of chemical shift.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
6.
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
7.
ELENA RAEVSKAYA MARCO VECOLI WIESAW BEDNARCZYK MARCO TONGIORGI 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2004,37(1):97-111
Billingen (Lower Arenig/Lower Ordovician) sediments of the St. Petersburg region, northwest Russia and the Leba area, northern Poland of the East European Craton yield acritarch assemblages, which are largely homogenous though displaying minor compositional differences that probably reflect a gradient from inner to outer shelf environments. Comparison with coeval acritarch microflora from the Yangtze Platform, South China, shows an overall similarity between Baltoscandian and South Chinese phytoplankton. The widespread uniformity in the fossil microphytoplankton may be related to the extensive global 'evae' sea-level transgression, which characterized the Billingen time. This suggests that during the Tremadoc through early Arenig times, acritarch assemblages displayed essentially an undifferentiated cold-water and oceanic character along the whole margin of Perigondwana in the South, as well as on the South Chinese and Baltic platforms, at middle latitudes (Mediterranean oceanic Realm). Despite this overall similarity, however, some typical taxa of the high-latitude Mediterranean Province (Arbusculidium, Coryphidium and Striatotheca) occur in South China, but are absent in Baltica. This discrepancy is explained as caused by differences in climatic and physiographic conditions that prevailed at the two palaeocontinents at this time. The inferred pattern of oceanic circulation during the Lower Ordovician is consistent with the palynological evidence of a prevailing warmer climate in Baltica than in South China, although the two palaeocontinents occupied the same palaeolatitudinal position. 相似文献
8.
Mice deficient for the lysosomal proteinase cathepsin D exhibit progressive atrophy of the intestinal mucosa and profound destruction of lymphoid cells. 总被引:16,自引:1,他引:15 下载免费PDF全文
P Saftig M Hetman W Schmahl K Weber L Heine H Mossmann A K?ster B Hess M Evers K von Figura et al. 《The EMBO journal》1995,14(15):3599-3608
Mice deficient for the major lysosomal aspartic proteinase cathepsin D, generated by gene targeting, develop normally during the first 2 weeks, stop thriving in the third week and die in a state of anorexia at day 26 +/- 1. An atrophy of the ileal mucosa first observed in the third week progresses towards widespread intestinal necroses accompanied by thromboemboli. Thymus and spleen undergo massive destruction with fulminant loss of T and B cells. Lysosomal bulk proteolysis is maintained. These results suggest, that vital functions of cathepsin D are exerted by limited proteolysis of proteins regulating cell growth and/or tissue homeostasis, while its contribution to bulk proteolysis in lysosomes appears to be non-critical. 相似文献
9.
Analysis of genetic diversity in common loon Gavia immer using RAPD and mitochondrial RFLP techniques 总被引:2,自引:0,他引:2
A. K. Dhar M. A. Pokras D. K. Garcia D. C. Evers Z. J. Gordon & A. Alcivar-Warren 《Molecular ecology》1997,6(6):581-586
We used random amplified polymorphic DNA (RAPD) and restriction fragment length polymorphisms (RFLP) of mitochondrial cytochrome b (cyt b ) gene to evaluate the genetic diversity in common loon Gavia immer populations from two regions in the United States: New England (NE) and Michigan (MI). RAPD analysis with 18 primers showed 74% polymorphism in NE and 50% in MI loons (similarity coefficient F = 0.92). Although no population-specific markers were found, the frequencies of some RAPD bands varied between the two populations suggesting geographical differences. RFLP analyses with Bam HI enzyme and a 307-bp mitochondrial cyt b gene showed four haplotypes in the NE loon samples and two in the MI samples. The mtDNA haplotype diversity was 0.74 for NE and 0.51 for MI loons, supporting the RAPD data that NE loons have greater genetic diversity than MI loons. 相似文献
10.
Jos C. F. M. Dreesen Joep P. M. Geraedts John C. M. Dumoulin Johannes L. H. Evers Math H. E. C. Pieters 《Human genetics》1995,96(3):323-329
In order to approach preimplantation testing for the fragile-X syndrome, we used genotyping of the polymorphic RS46(DXS548) locus closely linked to the FMR1 gene, in single reproductive cells of females. The RS46(DXS548) amplification was adjusted to the single cell level by a two-round polymerase chain reaction (PCR) procedure. Unfertilized oocytes and extruded polar bodies were subjected to PCR. RS46(DXS548) genotyping at the single cell level was successful in 95% of the samples. In two-third of the metaphase II oocytes and first polar bodies obtained from women who were heterozygous at the RS46(DXS548) locus, both maternal RS46(DXS548) alleles were observed because of crossing over during the first meiotic division. This makes gamete selection by first polar body analysis inefficient. From the allele frequencies found in 56 unrelated individuals, a heterozygote frequency of 51% was estimated, whereas the observed heterozygote frequency was 56%. The whole PCR procedure can be performed within 16 h after blastomere biopsy. Consequently, the selection and transfer of the diagnosed embryos can be carried out within an acceptable time. Therefore, preimplantation testing for the fragile-X syndrome with the RS46(DXS548) AC-repeat may be an alternative choice for prenatal testing for those carrier females who are heterozygous (informative) at the RS46(DXS548) locus. 相似文献