全文获取类型
收费全文 | 242篇 |
免费 | 34篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 10篇 |
2014年 | 9篇 |
2013年 | 11篇 |
2012年 | 10篇 |
2011年 | 19篇 |
2010年 | 14篇 |
2009年 | 6篇 |
2008年 | 15篇 |
2007年 | 15篇 |
2006年 | 16篇 |
2005年 | 9篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 8篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 8篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1977年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有276条查询结果,搜索用时 312 毫秒
1.
Summary Bacterial strains identified as Klebsiella pneumonia and Corynebacterium sp. degraded in few hours a great part of pure tara (Caesalpinia spinosa) tannin or crude water extract of tara pods powder. Large amounts of gallic acid were recovered during some experiments reaching 55 % of the theoretical yield in the best case. The feasibility of gallic acid production by a biotechnological process is discussed. 相似文献
2.
3.
4.
5.
An epithermal neutron activation method is used to determine the concentration of mineral elements in human dental enamel.
A large number (252) of samples from ancient and modern origins are analyzed. The analytical results are mathematically processed
using a statistical multivariant method. This allows to differentiate deciduous from permanent teeth and decayed from sound
enamel. It is also possible to distinguish the teeth coming from two different necropoles. The origin and the localization
of determined elements in the mineralized part, or in the aqueous-organic part, of enamel is suggested. Their role, as witnessed
in the physiopathological phenomena of dental enamel, is discussed. 相似文献
6.
Summary -glucosidase production was studied in solid-state cultivation by Aspergillus phoenicis on sugar beet pulps. The experiments were carried out in column incubators aerated with humidified air, at 30 °C. Results of physiological studies showed that the production of -glucosidase from beet pulps in the solid state fermentation required : 70% moisture content, initial pH of about 4, and 107 spores/g substrate. -glucosidase produced under these conditions could be removed from the solid medium with water, or stored in the form of a dried fermented product, for a direct use in the saccharification reactions. 相似文献
7.
Summary Anaerobic digestion of sugar beet pulps was studied in a 70 l digestor with sequential feeding, after enzymatic hydrolysis by Trichoderma harzianum cellulases. During the 130 days feeding, 3.6 m3 of biogas were produced with an average content of 58% CH4 from 270 l of hydrolysed pulps at 20 g VS/l. Average yield and production rate were respectively 0.67 m3/kg VS and 0.4 m3/ kg VS and 0.4 m3/m3 of digestor per day. 相似文献
8.
9.
High-resolution linkage mapping for susceptibility genes in human polygenic disease: Insulin-dependent diabetes mellitus and chromosome 11q 总被引:12,自引:7,他引:5 下载免费PDF全文
R. N. Hyer C. Julier J. D. Buckley M. Trucco J. Rotter R. Spielman A. Barnett S. Bain C. Boitard I. Deschamps J. A. Todd J. I. Bell G. M. Lathrop 《American journal of human genetics》1991,48(2):243-257
Insulin-dependent diabetes mellitus (IDDM) has a complex pattern of genetic inheritance. In addition to genes mapping to the major histocompatibility complex (MHC), several lines of evidence point to the existence of other genetic susceptibility factors. Recent studies of the nonobese diabetic mouse (NOD) model of IDDM have suggested the presence, on mouse chromosome 9, of a susceptibility gene linked to the locus encoding the T-cell antigen, Thy-1. A region on human chromosome 11q is syntenic to this region on mouse chromosome 9. We have used a set of polymorphic DNA markers from chromosome 11q to investigate this region for linkage to a susceptibility gene in 81 multiplex diabetic pedigrees. The data were investigated by maximization of lod scores over genetic models and by multiple-locus affected-sib-pair analysis. We were able to exclude the presence of a susceptibility gene (location scores less than -2) throughout greater than 90% of the chromosome 11q homology region, under the assumption that the susceptibility factor would cause greater than 50% of affected sib pairs to share two alleles identical by descent. Theoretical estimates of the power to map susceptibility genes with a high-resolution map of linked markers in a candidate region were made, using HLA as a model locus. This result illustrates the feasibility that IDDM linkage studies using mapped sets of polymorphic DNA markers have, both for other areas of the genome in IDDM and for other polygenic diseases. The analytic approaches introduced here will be useful for affected-sib-pair studies of other complex phenotypes. 相似文献
10.
Ventilation and electromyogram (EMG) activities of the right hemidiaphragm, parasternal intercostal, triangularis sterni, transversus abdominis, genioglossus, and alae nasi muscles were measured before and during central stimulation of the left thoracic phrenic nerve in 10 alpha-chloralose anesthetized vagotomized dogs. Pressure in the carotid sinuses was fixed to maintain baroreflex activity constant. The nerve was stimulated for 1 min with a frequency of 40 Hz and stimulus duration of 1 ms at voltages of 5, 10, 20, and 30 times twitch threshold (TT). At five times TT, no change in ventilation or EMG activity occurred. At 10 times TT, neither tidal volume nor breathing frequency increased sufficiently to reach statistical significance, although the change in their product (minute ventilation) was significant (P less than 0.05). At 20 and 30 times TT, increases in both breathing frequency and tidal volume were significant. At these stimulus intensities, the increases in ventilation were accompanied by approximately equal increases in the activity of the diaphragm, parasternal, and alae nasi muscles. The increase in genioglossus activity was much greater than that of the other inspiratory muscles. Phrenic nerve stimulation also elicited inhomogeneous activation of the expiratory muscles. The transversus abdominis activity increased significantly at intensities from 10 to 30 times TT, whereas the activity of the triangularis sterni remained unchanged. The high stimulation intensities required suggest that the activation of afferent fiber groups III and IV is involved in the response. We conclude that thin-fiber phrenic afferent activation exerts a nonuniform effect on the upper airway, rib cage, and abdominal muscles and may play a role in the control of respiratory muscle recruitment. 相似文献