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Marie Pauline J. Evers Bauke Zelle Daniel S. Peeper Willem H. Mager Rudi J. Planta Aldur W. Eriksson Rune R. Frants 《Human genetics》1987,77(2):182-187
Summary Three human cosmid clones containing pepsinogen A (PGA) encoding sequences were isolated from a genomic bank derived from a single individual. One cosmid contains two PGA genes in tandem in a head-to-tail orientation, while the other two cosmids each contain a single PGA gene. The three cosmids were characterized by restriction mapping and sequence analysis (exons 1 and 2 and flanking regions). As judged from these data, three of the four PGA genes isolated appear to be nearly identical, but one of the tandem genes is clearly different from the other genes. The first exon of all four genes codes for the same amino acid sequence. However, in the second exon of one of the tandem genes we found a nucleotide substitution giving rise to a GluLys substitution of the 43rd amino acid residue of the activation peptide, leading to a charge difference of the corresponding isozymogens. The presence of two distinct PGA genes in the isolated gene pair conclusively proves the multigene structure of the PGA system. These genes might be responsible for at least part of the electrophoretic polymorphism at the protein level. 相似文献
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The genes coding for histone H3 and H4 in Neurospora crassa are unique and contain intervening sequences. 总被引:39,自引:14,他引:25 下载免费PDF全文
L P Woudt A Pastink A E Kempers-Veenstra A E Jansen W H Mager R J Planta 《Nucleic acids research》1983,11(16):5347-5360
Sequences coding for histone H3 and H4 of Neurospora crassa could be identified in genomic digests with the use of the corresponding genes from sea urchin and X. laevis as hybridization probes. A 2.6 kb HindIII-generated N. crassa DNA fragment, showing homology with the heterologous histone H3-gene probes was cloned in a charon 21A vector. Using DNA from this clone as a homologous hybridization probe a 6.9 kb SalI-generated DNA fragment was isolated which in addition to the histone H3-gene also contains the gene coding for histone H4. Several lines of evidence demonstrate the presence of only a single histone H3- as well as a single histone H4-gene in N. crassa. The two genes are physically linked on the genome. DNA sequencing of the N. crassa histone H3- and H4-genes confirmed their identity and, in addition, revealed the presence of one short intron (67 bp) within the coding sequence of the H3-gene and even two introns (68 and 69 bp) within the H4-gene. The amino acid sequences of the N. crassa histones H3 and H4, as deduced from the DNA sequences, and those of the corresponding yeast histones differ only at a few positions. Much larger sequence differences, however, are observed at the DNA level, reflecting a diverging codon usage in the two lower eukaryotes. 相似文献
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Mapping of B-neutralizing and T-helper cell epitopes on the bovine leukemia virus external glycoprotein gp51. 总被引:4,自引:3,他引:1 下载免费PDF全文
I Callebaut V Vonche A Mager O Fumire V Krchnak M Merza J Zavada M Mammerickx A Burny D Portetelle 《Journal of virology》1993,67(9):5321-5327
A battery of 19 synthetic peptides was used to characterize efficient neutralizing and helper T-cell epitopes on the bovine leukemia virus (BLV) external envelope glycoprotein gp51. Four of the antipeptide antisera raised in rabbits inhibited the formation of BLV-induced syncytia; these antisera are directed against peptides 64-73, 98-117, and 177-192. Only antisera directed against the 177-192 region also neutralized vesicular stomatitis virus-BLV pseudotypes. This study clearly demonstrates that neutralizing properties can be observed with antibodies raised to regions undescribed so far and included in both the amino-terminal and central parts of the antigen. In addition, some helper T-cell determinants were defined from gp51-immunized mice and from BLV-infected cattle. Although none of the peptides tested behaved as a universal helper T-cell epitope, peptide 98-117 stimulated T-cell proliferation from BALB/c mice and from three infected cows, while peptide 169-188 strongly stimulated T-cell proliferation from one infected cow. Further experiments performed with three peptides overlapping the 169-188 region (177-192, 179-192, 181-192) demonstrated the particular relevance of residue(s) P-177 and/or D-178 in the helper T-cell epitope. These data should assist in the design of an efficient subunit vaccine against BLV infection that contains peptides possessing both B-neutralizing and helper T-cell determinants. 相似文献
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R W Hubbard W T Matthew D Horstman R Francesconi M Mager M N Sawka 《Journal of applied physiology (Bethesda, Md. : 1985)》1984,56(5):1361-1368
To develop a reliable procedure for the acute expansion of plasma volume (PV), 26 male volunteers were randomly assigned to either a thermoneutral (25 degrees C and 40% relative humidity) or hot-dry (37 degrees C and 25% relative humidity) environment; subsequently each subject was seated for at least 1 h and then infused intravenously with either 100 or 200 ml of a 25% albumin solution or 0.9% saline. On the day before each infusion, PV was estimated by dye dilution using indocyanine green. Net percent change in PV (using hematocrit and hemoglobin values) was calculated at 1, 3, 6, 9, 12, and 24 h postinfusion. The PV of subjects residing in the heat after a 100-ml saline infusion increased significantly over 1-h values at 6, 9, and 12 h postinfusion but not at 24 h. The same trend, although not significant, was apparent at room temperature. The data suggest a slow isooncotic circadian pattern of PV expansion and contraction. The infusion of hyperoncotic albumin produced rapid expansion of plasma volume. With the low dose (25 g) at 1 h postinfusion, the expansion was 379 +/- 102 ml in the heat and 301 +/- 160 ml at room temperature. With the high dose (50 g) at 1 h postinfusion, the expansion was 479 +/- 84 ml in the heat and 427 +/- 147 ml at room temperature. The high dose produced an expansion that persisted for at least 9 h in subjects in either environment. The data suggest a mechanism for the retention of fluid during heat acclimatization and a useful procedure for plasma volume expansion in humans. 相似文献
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Rats were exercised on a treadmill (9.14 m/min) in a hot environment (34.5 degrees C, 30% rh) until a rectal temperature of 42.0--42.5 degrees C was reached. Analysis of plasma constituents in subsequent serial blood samples demonstrated a highly significant inverse correlation between lactate concentration (P less than 0.001) and potassium levels (P less than 0.005) in blood samples taken immediately postexercise when both of these were correlated to survival time. Alternatively, plasma creatine phosphokinase (CPK) activity in these samples, although significantly elevated over control levels (P less than 0.001), was not correlated with either survival time or lactate-potassium concentrations. When fluid was administered prior to the run and immediately thereafter to repress pathological effects, there occurred no changes in plasma lactate and potassium levels between the postrun sample and a second sample taken 60 min later, while CPK levels were significantly reduced (P less than 0.01) in the second sample. However, levels of all three indices were significantly elevated (P less than 0.01) in a third sample taken terminally despite the fact that the animals were restrained and sedentary during this interval. These findings indicate that the hyperthermic injury may have had fundamental pathological effects on metabolism and membrane integrity producing lactacidemia and hyperkalemia of sufficient magnitude to compromise cardiovascular performance. 相似文献