全文获取类型
收费全文 | 1488篇 |
免费 | 109篇 |
专业分类
1597篇 |
出版年
2023年 | 5篇 |
2022年 | 23篇 |
2021年 | 32篇 |
2020年 | 21篇 |
2019年 | 35篇 |
2018年 | 44篇 |
2017年 | 30篇 |
2016年 | 51篇 |
2015年 | 84篇 |
2014年 | 90篇 |
2013年 | 105篇 |
2012年 | 122篇 |
2011年 | 129篇 |
2010年 | 57篇 |
2009年 | 76篇 |
2008年 | 97篇 |
2007年 | 102篇 |
2006年 | 74篇 |
2005年 | 54篇 |
2004年 | 61篇 |
2003年 | 62篇 |
2002年 | 61篇 |
2001年 | 16篇 |
2000年 | 10篇 |
1999年 | 24篇 |
1998年 | 14篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1981年 | 7篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1974年 | 4篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1968年 | 6篇 |
1967年 | 2篇 |
1965年 | 3篇 |
1957年 | 2篇 |
排序方式: 共有1597条查询结果,搜索用时 0 毫秒
1.
Distinct transcriptional profiles of adipogenesis in vivo and in vitro. 总被引:14,自引:0,他引:14
A Soukas N D Socci B D Saatkamp S Novelli J M Friedman 《The Journal of biological chemistry》2001,276(36):34167-34174
2.
A frameshift mutation (2869insG) in the second transmembrane domain of the CFTR gene: identification, regional distribution, and clinical presentation. 下载免费PDF全文
3.
In a new case of interstitial del(2q), measurements of ribulose 5-phosphate 3-epimerase activity suggested that the locus for this enzyme might be localized to the subregion 2q32q33.3. 相似文献
4.
A. Novelli M. T. Fernández-Sánchez J. Kispert A. Torreblanca S. Gascón V. Zitko 《Amino acids》1992,2(3):233-244
Summary A recent episode of human intoxication by cultured mussels containing a rare excitatory amino acid named domoic acid, received particular attention for its neurological implications. The intoxication produced neurological problems, such as headache, confusion, and loss of memory, particularly severe at times. Neuronal damage was found in the hippocampus and amygdala of four patients. We now report that in neuronal cultures the neurotoxicity of a domoic acid-containing mussel extract is the result of domoic acid potentiation of the excitotoxic effect of glutamic acid and aspartic acid present in high amounts in mussel tissue. Moreover, we show that subtoxic concentrations of domoic acid are sufficient to potentiate glutamic acid and aspartic acid neurotoxicity. We present evidence suggesting that the neurotoxic synergism may be due to a reduction of Mg+ + block at the NMDA receptor-associated channel, following activation of NON-NMDA receptors by domoic acid. 相似文献
5.
Platelet immune complex interaction in pathogenesis of Kawasaki disease and childhood polyarteritis.
M Levin P C Holland T J Nokes V Novelli M Mola R J Levinsky M J Dillon T M Barratt W C Marshall 《BMJ (Clinical research ed.)》1985,290(6480):1456-1460
The role of platelets in the pathogenesis of vasculitis and the formation of coronary artery aneurysms was studied in 19 children with Kawasaki disease and five with polyarteritis. All patients with Kawasaki disease developed thrombocytosis in the third week of illness. The peak platelet count was significantly correlated (p less than 0.005) with the subsequent development of coronary artery aneurysms. The rise in platelet count was associated with the appearance in the circulation of a factor that induced aggregation and serotonin release in normal platelets. This factor was shown to be of high molecular weight, and its activity was lost at low pH--features suggestive of an immune complex. Immune complexes, detected by precipitation with polyethylene glycol, also appeared in the circulation as the platelet count increased. These complexes induced platelet aggregation, and there was a significant correlation (p less than 0.001) between the concentrations of IgG and IgA in the polyethylene glycol precipitated material and the platelet aggregating activity. Similar platelet aggregating activity was also detected in patients with polyarteritis but followed a different time course, persisting in the circulation for several months in association with continued disease activity. These findings imply that different mechanisms have a role in distinct phases of Kawasaki disease. The initial feverish phase (probably infective) is probably followed by an immune complex vasculitis that occurs when antibodies to the initiating agent appear in the circulation. The immune complexes aggregate platelets and induce release of serotonin. Platelet derived vasoactive mediators may increase vascular permeability and facilitate further deposition of complexes in the tissues. 相似文献
6.
Liver microsomal fractions were prepared from rats injected with a single dose of choline [14C] methylchloride or with single or multiple doses of 32Pi. Exchangeability of microsomal phospholipids was determined by incubation with an excess of mitochondria and phospholipid exchange proteins derived from beef heart, beef liver or rat liver. Labeled phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were found to act as a single pool and were 85–95% exchangeable in 1–2 h. High latencies of mannose-6-phosphate phosphohydrolase activities and impermeability of microsomes to EDTA proved that phospholipid exchange proteins did not have access to the intracisternal space. If microsomal membranes are largely composed of phospholipid bilayers, the experiments suggest that one or more of the phospholipid classes in microsomal membranes undergo rapid translocation between the inner and outer portions of the bilayer. 相似文献
7.
B A Saxty R Novelli R E Dolle L I Kruse D G Reid P Camilleri T N Wells 《European journal of biochemistry》1991,202(3):889-896
The enantiomers (+) and (-)-2,2-difluorocitrate have been synthesized. Both are good inhibitors of ATP-citrate lyase, showing competitive inhibition against citrate, with Kis = 0.7 microM for (+)-2,2-difluorocitrate and 3.2 microM for (-)-2,2-difluorocitrate. The inhibition patterns with either ATP or CoA as the varied substrate were uncompetitive and mixed, respectively, but with much weaker inhibition constants. Neither isomer undergoes carbon-carbon bond cleavage as a substrate and there is no evidence of irreversible time-dependent inactivation. When ATP-citrate lyase is incubated with CoA and difluorocitrate, the maximal intrinsic ATPase rate is 10% of the citrate-induced rate for the (+)-enantiomer and 2% for the (-)-enantiomer. 19F-NMR studies confirm that only the (+)-enantiomer is chemically processed. The effects of the difluorocitrate enantiomers on the reaction catalysed by aconitase were examined. (-)-2,2-Difluorocitrate is a competitive inhibitor against citrate (Kis = 1.5 microM), whereas the (+)-enantiomer is a relatively poor mixed inhibitor (Ki greater than 300 microM). The (-)-enantiomer irreversibly inactivates aconitase at 1.1 min-1.mM-1 at 25 degrees C and pH 7.4, whereas no irreversible inhibition is seen with the (+)-enantiomer. Therefore, it would be expected that the (+)-enantiomer would slow the rate of acetyl-CoA synthesis in vivo, without inhibiting the citric acid cycle. 相似文献
8.
The search for south European cystic fibrosis mutations: identification of two new mutations, four variants, and intronic sequences 总被引:25,自引:0,他引:25
P Gasparini V Nunes A Savoia M Dognini N Morral A Gaona A Bonizzato M Chillon F Sangiuolo G Novelli 《Genomics》1991,10(1):193-200
The major mutation in the cystic fibrosis (CF) gene is a 3-bp deletion (delta F508) in exon 10. About 50% of the CF chromosomes in Southern Europe carry this mutation, while other previously described mutations account for less than 4%. To identify other common mutations in CF patients from the Mediterranean area, we have sequenced, exon by exon, 16 chromosomes that did not show the delta F508 deletion from a selected panel of eight unrelated CF patients. We describe here one missense and one nonsense mutation, and four sequence polymorphisms. We have also found two previously reported mutations in three chromosomes. Overall, these mutations may account for about 20% of CF alleles in the Italian and Spanish populations. No other mutations were detected in 10 out of 16 CF chromosomes after analyzing about 90% of the coding region of the CF gene, and 39 out of 54 intron/exon boundaries. Therefore, about 26% of CF mutations remain to be identified. In addition we provide the intron/exon boundary sequences for exons 4 to 9. These results together with previously reported linkage data suggest that in the Mediterranean populations further mutations may lie in the promoter region, or in intron sequences not yet analyzed. 相似文献
9.
Roberto Pilu Andrea Bucci Laura Casella Chiara Lago Francesco Cerino Badone Elena Cassani Michela Landoni 《Molecular breeding : new strategies in plant improvement》2012,30(2):799-807
We produced and studied for 3?years two synthetic populations of maize differing in their constitution only for the selected alleles present at the red color 1 (r1) locus (R-sc vs. r?Cr). r1 is a regulatory gene conferring anthocyanin pigmentation in different tissues: the R-sc allele confers pigmentation only in the aleurone seed layer, while the r?Cr allele confers pigmentation in several tissues such as root, silk and anther but the seed is colourless. The colourless population (r?Cr/r?Cr) was characterized by improved agronomic features, such as ear weight and plant height, compared with the R-sc/R-sc coloured population. This finding was confirmed by studying single F4 R/r families where the presence of the r?Cr allele conferred positive features, acting as a dominant trait. Quantitative trait locus (QTL) analysis performed using molecular markers on the long arm of chromosome 10 (bin 10.06), where the r1 gene maps, identified a QTL map position for plant height tightly associated to the r1 gene. Thus the r1 gene may represent a major QTL or it could be closely linked to another gene involved in the agronomic performance of the two populations studied. 相似文献
10.