解剖学和形态学
麻醉学
听力与言语-语言病理学
行为科学
心脏和心血管系统
细胞和组织工程学
临床神经病学
危重症监护医学
牙科,口腔外科和医学
皮肤病学
急诊医学
内分泌学和新陈代谢
肠胃学和肝脏学
老人病学和老年医学
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血液学
免疫学
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综合和补充性医学
医学伦理学
医学信息学
医学实验室技术
医学,全科和内科
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神经系统科学
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基本医疗保健
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心理学,临床
abstract::The nucleoside compositions of chloroplast and cytoplasmic tRNAPhe's from Euglena gracilis have been determined. The modified nucleoside compositions of these two tRNAs indicate that tRNAPheChl is more similar to procaryotic (E. coli) tRNAPhe than to either the Euglena cytoplasmic tRNAPhe or other eucaryotic cytoplasm...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/3.2.371
更新日期:1976-02-01 00:00:00
abstract::The synthesis of ribosomal precursor RNA in Novikoff hepatoma (N1S1) cells is very sensitive to cordycepin (3'-dA). The synthesis of hnRNA, however, is resistant to inhibition concentrations of 3'-dA that completely block the synthesis of 45S ribosomal RNA precursor. We have examined the RNA polymerases present in the...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/3.2.325
更新日期:1976-02-01 00:00:00
abstract::Ethidium causes the cleavage of DNA via a light and oxygen dependent process. Using covalently closed circular DNA as a substrate, the saturation kinetics and the dependence on superhelical density of the cleavage indicate that intercalated ethidium is mainly responsible for nicking DNA. Superoxide dismutase has littl...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/3.2.315
更新日期:1976-02-01 00:00:00
abstract::Inosine was prepared (15% yield) by treatment of 5-amino-1-beta-D-ribofuranosyl-4-imidazolecarboxamide (AICA-riboside) with chloroform in the presence of sodium methoxide. This ring closure can be reasonably explained by assuming the formation of dichlorocarbene from chloroform and alkali. Carbon tetrachloride or hexa...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/3.1.231
更新日期:1976-01-01 00:00:00
abstract::Terminal deoxynucleotidyl transferase, which requires a single-stranded DNA primer under the usual assay conditions, can be made to accept double-stranded DNA as primer for the addition of either rNMP or dNMP, if Mg+2 ion is replaced by Co+2 ion. The priming efficiency in the presence of (C leads to) CO+2 ion with res...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/3.1.101
更新日期:1976-01-01 00:00:00
abstract::Mouse globin messenger ribonucleoprotein (mRNP) has been isolated from reticulocyte polysomes by affinity chromatography to oligo(T)-cellulose, using a procedure modified from that of Lindberg and Sundquist. The messenger RNA and protein moieties fo the mRNP are indistinguishable from those isolated by less rapid tech...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.12.2251
更新日期:1975-12-01 00:00:00
abstract::A detailed scheme of the Peptidyl Transferase Centre of bacterial ribosomes is proposed by summarizing the literature data on the substrate specificity of the acceptor and donor sites. According to the proposed scheme only the elements of the donor and acceptor having a stable structure bind with the ribosome. The pre...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.12.2223
更新日期:1975-12-01 00:00:00
abstract::Two DNA polymerases have been purified from the 105,000 x g supernatant of ungerminated wheat. The purification stages included: high speed centrifugation, salt fractionation, DEAE-cellulose chromatography, Sephadex G-150 filtration and phosphocellulose chromatography. Several properties of the two enzyme (called A an...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.11.2077
更新日期:1975-11-01 00:00:00
abstract::A peptide initiation factor purified from rat liver and promoting the binding of initiator tRNA and model initiators to 40S and 80S ribosome at an acid pH liberates methionine and N-acetylmethionine from Trna Met f at neutral reaction. Phenylalanyl-tRNA, N-acetylphenylalanyl-tRNA and methionyl-tRNA Met m are not hydro...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.11.2119
更新日期:1975-11-01 00:00:00
abstract::Specific DNA restriction endonuclease fragments can be identified after electrophoresis in agarose gels by hybridization in the gel (in situ) to radioactive homologous RNA. RNA-DNA hybrids are detected by autoradiography of the gel. Comparison of band patterns of the autoradiogram and the ethidium bromide stained gel ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.10.1911
更新日期:1975-10-01 00:00:00
abstract::A DNA methylase has been purified 270-fold from HeLa cell nuclei by chromatography on DEAE-cellulose, phosphocellulose, and hydroxyapatite. The enzyme transfers methyl groups from S-adenosyl-L-methionine to cytosine residues in DNA. The sole product of the reaction has been identified as 5-methylcytosine. The enzyme i...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.10.1669
更新日期:1975-10-01 00:00:00
abstract::The modified nucleoside, 7-(4,5-cis-dihydroxy-1-cyclopenten-3-yl-aminomethyl)-7-deazaguanosine, designated as Q, and its derivative, Q*, were found in tRNA's from various organisms, including several mammalian tissues, other animals such as starfish, lingula and hagfish, and wheat germ. Q isolated from rat liver tRNA ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.10.1931
更新日期:1975-10-01 00:00:00
abstract::In the presence of S-adenosyl methionine the 5' terminal guanosine residue of in vitro synthesized reovirus mRNA becomes methylated at the 2'-OH position. In addition, 7-methyl guanylic acid is condensed covalently at the 5' terminus resulting in the formation of a 5' to 5' triphosphate bridge. Analysis of the 5' term...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.8.1329
更新日期:1975-08-01 00:00:00
abstract::Synchronous plasmodia of Physarum polycephalum in DNA synthesis were pulse-labelled with [oH]- thymidine for time periods of 15 seconds up to 9 minutes, or given a 30 seconds pulse followed by chase periods of 9 minutes up to 6 hours. Sedimentation analysis in alkaline sucrose gradients revealed at least five species ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.8.1381
更新日期:1975-08-01 00:00:00
abstract::Aspects of the metabolism of RNA have been studied in enzymatically isolated protoplasts from cotyledon and first leaf mesophyll tissue of two cultivars of cucumber. The first leaf mesophyll protoplasts incorporated (3H)-uridine into ribosomal RNA at a constant rate for up to 25 hr in a simple salts medium and for up ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.7.1111
更新日期:1975-07-01 00:00:00
abstract::Two new endonuclease activities, endonuclease B and endonuclease C, obtained from yeast nuclear preparations have been separated and partially characterized. Endonuclease B has a primary requirement for Mn2+ which cannot be replaced by Mg2+ or Ca2+, and makes single-strand scissions in double-stranded DNA. Endonculeas...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.7.1023
更新日期:1975-07-01 00:00:00
abstract::The effect of [Na+] on the stability and conformation of penicillium chrysogenum mycophage dsRNA (PCMdsRNA) was investigated using CD and UV optical techniques. Thermal melting profiles reveal prominent fine structure attributed to at least four regions of structural dissimilarity. A constant increased thermal stabili...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.6.759
更新日期:1975-06-01 00:00:00
abstract::A study of the synthesis of oligothymidylates via phosphotriester intermediates on a polystyrene support is described. The sequence involves condensation of a phenyl nucleoside-3' -phosphorochloridate with the 5'-hydroxyl group of the carrier bound oligonucleotide derivative in the presence of 1-methylimidazole. Condi...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.6.773
更新日期:1975-06-01 00:00:00
abstract::The structure of eukaryotic chromatin has been investigated by isolating and analyzing the "accessible" DNA fraction of rat liver chromatin. This DNA fraction has been isolated by titrating the chromatin with the protese-resistant D isomer of polylysine to bind the "accessible" DNA sites. After removal of chromosomal ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.5.667
更新日期:1975-05-01 00:00:00
abstract::E. coli C6 rel- met- cys- was cultured in a fully supplemented medium and in media lacking cysteine or methionine. tRNA isolated from the three cultures containted, respectively, a normal complement of modified nucleosides; a deficiency in thiolated nucleosides and a deficiency in methylated nucleosides. Both sulfur-d...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.5.691
更新日期:1975-05-01 00:00:00
abstract::In vitro repair of single strand breaks in T4 and phage DNA caused by 32p decay was studied. Zone centrifugation procedure showed that polynucleotide kinase, ligase enzyme system failed to repair 32P-damages. It was found that damaged DNA contained gaps and could be repaired by DNA-polymerase I, polynucleotide ligase ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.5.635
更新日期:1975-05-01 00:00:00
abstract::A minor tRNA-Glu1 constituent of a preparation of E. coli B tRNA-Glu (Oak Ridge) has a guanosine residue at position 66 rather than an adenosine as in the tRNA-Glu2 described by Ohashi et al. (3). Automated sequential degradation was used to sequence this region. ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.4.469
更新日期:1975-04-01 00:00:00
abstract::Symmetry considerations of the kind of structures which can be generated when dimers of histones f2al-f3 and f2a2-f2b interact lead to the following conclusions: chromatin subunits based on closed-shell structures give rise to discrete, non-interacting nucleoprotein subunits with the histones arranged at random along ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.3.405
更新日期:1975-03-01 00:00:00
abstract::The thermal denaturation spectra of E. coli 50s and 30s ribosomal sub units and of their isolated RNA's were studied over the wavelength range of 2300-3000 Angstrom. It was possible to fit the experimental denaturation spectra with super positions of the reference spectra for denaturation of A - U and G - C base pairs...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.3.373
更新日期:1975-03-01 00:00:00
abstract::The role of thymine dimerization for previously reported U.V. induced conformational changes has been proved using acetophenone as sensitizer for the specific thymine dimerization upon irradiation at 313 nm. CD results demonstrate that formation of pyrimidine dimers cause typical conformational changes of the DNA B he...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.2.179
更新日期:1975-02-01 00:00:00
abstract::The interaction of RNase T1 with calf thymus DNA was studied using uv difference spectroscopy and the effect of the enzyme on DNA melting. There was no indication of RNase T1 binding with native DNA. A prominent difference spectrum for RNase T1 binding with denatured DNA (d-DNA) was observed at pH 5, 25 degrees and lo...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/2.1.11
更新日期:1975-01-01 00:00:00
abstract::The reaction of the tetranucleotide, pA-A(2)-A, with 2'(3')-0-(alpha-methoxyethyl)uridine 5'-diphosphate, Mg(2+) ions, and M. luteus polynucleotide phosphorylase followed by mild acid treatment to remove the blocking groups results in a 49% yield of the desired single addition product, pA-A(3)-U, together with smaller...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.12.1665
更新日期:1974-12-01 00:00:00
abstract::Several fungal species, representatives of all broad groups like basidiomycetes, ascomycetes and phycomycetes, were examined for the nature of repeated DNA sequences by DNA:DNA reassociation studies using hydroxyapatite chromatography. All of the fungal species tested contained 10-20% repeated DNA sequences. There are...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.11.1411
更新日期:1974-11-01 00:00:00
abstract::The effect of several rifamycin derivatives on poly(A) synthesis in vitro was tested using purified rat liver mitochondrial poly(A) polymerase assayed with an exogenous primer. When used at a concentration of 300 mug/ml, derivatives AF/013, PR/19, AF/AETP, M/88 and AF/ABDP completely inhibited activity corresponding t...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.11.1549
更新日期:1974-11-01 00:00:00
abstract::The nucleotide sequence of a T4 tRNA with an anticodon for glycine has been determined using (32)P-labeled material from T4-infected cultures of Escherichiacoli. The sequence is: pGCGGAUAUCGUAUAAUGmGDAUUACCUCAGACUUCCAApsiCUGAUGAUGUGAGTpsiCGAUUCUCAUUAUCCGCUCCA-OH. The 74 nucleotide sequence can be arranged in the class...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.10.1287
更新日期:1974-10-01 00:00:00
abstract::In apurinic acid, a single-stranded polydeoxyribonucleotide easily obtained upon depurination of DNA, the proton resonances arising from thymine and cytosine are readily observable in aqueous solution of 25 degrees C. Two methyl thymine resonances, centered at 1.88 ppm and separated by 0.045 ppm, are observed. We attr...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.8.999
更新日期:1974-08-01 00:00:00
abstract::We previously proposed that the first enzyme for histidine biosynthesis in Salmonellatyphimurium plays a role in regulating expression of the histidine operon and that in order to play this role the enzyme must form a complex with histidyl-tRNA. Among the many observations that led to these conclusions were 1) that re...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.7.881
更新日期:1974-07-01 00:00:00
abstract::Conformations of 8-bromo-2'-[unk]-triisopropylbenzenesulfonyladenosine ([unk]) and its 3'-[unk]-isomer ([unk]) in solution have been determined by the use of intramolecular nuclear Overhauser effects in (1)H NMR spectroscopy. Compound [unk] has been proved to have a conformation in which the adenosine and benzene ring...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.6.823
更新日期:1974-06-01 00:00:00
abstract::Mung bean nuclease hydrolyzes synthetic esters of 3'-nucleotides to nucleosides and phosphate esters; esters of 2'-nucleotides, and 2'--> 5' internucleotide linkages, are resistant. Esters of ribonucleotides are cleaved at 100-fold the rate for deoxyribonucleotides, the increased rate being due to presence of the 2'-h...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.5.699
更新日期:1974-05-01 00:00:00
abstract::Nuclear DNA from liver cells of the kangaroo rat species Dipodomysordii was fractionated and characterized with the aid of buoyant density gradients in neutral and alkaline CsCl and in Ag(+)-Cs(2)SO(4). More than one-half of the DNA was present in three density satellites, a greater proportion than in any other specie...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.4.559
更新日期:1974-04-01 00:00:00
abstract::Several electrophoretic and chromatographic systems have been investigated and compared for sequence analysis of oligodeoxyribonucleotides. Three systems were found to be useful for the separation of a series of sequential degradation products resulting from a labeled oligonucleotide: (I) 2-D electrophoresisdagger; (I...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.3.331
更新日期:1974-03-01 00:00:00
abstract::A dinucleoside monophosphate, 6,2'-anhydro-6-oxy-1-beta-D-arabinofuranosyluracil-phosphoryl- (3'-5')-6,2'-anhydro-6-oxy-1-beta-D-arabinofuranosyluracil (I) was synthesized by the condensation reaction using DCC from 5'-monomethoxytrityl derivative(VII) and 3'-acetyl-5'-phosphate(X) of the monomer units. Yield was ca. ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.3.479
更新日期:1974-03-01 00:00:00
abstract::In 2.5 x 10(-4)M EDTA buffer, the derivative melting curve of calf thymus DNA shows a major band at 47 degrees with a shoulder at about 54 degrees . The fraction of melting area of this shoulder is about 13%. For reconstituted polylysine-calf thymus DNA complexes, in addition to the melting of free DNA regions at abou...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.2.257
更新日期:1974-02-01 00:00:00
abstract::Stability of aromatic phosphoramidates was studied using 2',3'-O-dibenzoyluridine 5'-phosphoramidates and N,2',3'-O-tribenzoylcytidine 5'-phosphate. The effect of dicyclohexylcarbodiimide in this mixture was investigated. Decomposition of the anilidate was slower in the presence of DCC. Substituted anilidates of uridi...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.2.223
更新日期:1974-02-01 00:00:00
abstract::Calf lens messenger fractions have been purified on poly(dT)-cellulose. The purified RNA's have been analyzed as nucleosides by a method which can be used on a micro-scale with highly reproduceble results. Both the 10S and 14S lens mRNA contain poly A sequences. The poly A content found in 14S mRNA cannot account for ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/1.2.245
更新日期:1974-02-01 00:00:00