全文获取类型
收费全文 | 211篇 |
免费 | 0篇 |
出版年
2013年 | 4篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 3篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 11篇 |
2006年 | 4篇 |
2005年 | 10篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 11篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 8篇 |
1982年 | 4篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 1篇 |
1972年 | 3篇 |
1971年 | 5篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1965年 | 1篇 |
1959年 | 1篇 |
1958年 | 3篇 |
1957年 | 3篇 |
1955年 | 6篇 |
1954年 | 3篇 |
排序方式: 共有211条查询结果,搜索用时 312 毫秒
1.
LINDA M. McINNES IAN R. DADOUR MEREDITH E. STEWART WILLIAM G. F. DITCHAM PETER MAWSON PETER B. S. SPENCER 《Molecular ecology resources》2005,5(3):504-506
Microsatellite loci were isolated from Carnaby's black cockatoo (Calyptorhynchus latirostris: Aves), a highly valued, endangered, and endemic species of bird from Western Australia. This study describes three dinucleotide and one tetranucleotide microsatellite loci for which the primers produced clear and polymorphic amplification patterns with between two and nine alleles and moderate levels of variability. Two additional dinucleotide markers which were monomorphic in the Carnaby's cockatoo were able to amplify and were polymorphic in two other species of black cockatoo, greatly increasing the utility of these markers. 相似文献
2.
There is evidence in crustaceans that neuroendocrine centers,including the eyestalk, brain, thoracic ganglionic mass, andpericardial organ, produce factors that affect osmotic and ionicregulation. Understanding of the processes responsible for osmoticadjustment in the intact animal, such as regulation of permeability,active uptake of ions, and respiratory and cardiovascular alterations,has increased substantially in the past few years. However,interaction of neuroendocrine factors with the target tissuesand systems is just beginning to be investigated. There is evidencethat content of lipids and activity of enzymes are importantin osmoregulation, and neuroendocrine effects on these metabolicprocesses are worthy of study. In addition, there are some crustaceansin which osmoregulatory ability varies developmentally. Furtherinvestigations of such animals is also necessary. Progress inour understanding of neuroendocrine influences on osmoregulationdepends upon further purification of active factors from neuroendocrinecenters and hemolymph, and upon development of appropriate assayson which to test them. 相似文献
3.
ABSTRACT. The purpose of this research was to determine whether mice could be protected from lethal challenge with Naegleria fowleri by prior intranasal exposure to pathogenic and nonpathogenic Naegleria. Mortality ranged from 0 to 100% for mice inoculated intranasally (i.n.) with 5 × 103 amebae of 13 human isolates of N. fowleri. Mice were immunized and challenged i.n. using live amebae of strains of low, medium, and high virulence. The greatest protection against lethal challenge was afforded by three immunizing doses of 103 amebae per dose of the strain of medium virulence. Nonpathogenic N. gruberi also was used to immunize mice i.n. against lethal challenge with N. fowleri. Protection was greater following immunization with N. gruberi than it was after immunization with N. fowleri, suggesting that nonpathogenic N. gruberi may be a better immunogen in protecting mice against lethal naeglerial challenge. 相似文献
4.
The successional sequences of microbial colonization of Centrocerasclavulatum, Bryocladia cuspidata, and Gelidium crinale wereobserved by SEM. Colonization was initiated by filamentous andsmaller rod or coccoid bacteria, and these microbes were replacedby diatom populations in a successional pattern on Centrocerasand Bryocladia. Gelidium was colonized primarily by bacteria.The spatial fouling patterns on each host plant could be correlatedwith plant shape. Differences in epiphyte attachment morphologiescould be correlated in some species with the host plant or withthe position of the epiphyte on the host plant. Diatoms, epiphytes, fouling, microbial colonization, periphyton 相似文献
5.
LINDA ANITA RITTERBUSH 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1983,16(4):309-310
Specimens of Peronopsis and Ptychagnostus from the House Range of western Utah provide new information on the location of the labrum (hypostoma) of agnostid trilobites. A labral position as that described here, beneath the second glabellar lobe, has two implications: (1) anomalous cephalic muscle scars described by previous workers may be interpreted as attachment areas for labral muscles; and (2) the mouth probably migrated posteriorly in agnostids. Posterior displacement of the mouth was probably one of several feeding modifications associated with a pelagic mode of life. 相似文献
6.
The Hill reaction of chloroplasts was inhibited by washing themwith 0.8 M Tris buffer. This inhibition was further promotedby adding ferricyanide in the washing medium. When a reducingreagent, such as the 2,6-dichlorophenol indophenol (DCPIP)-ascorbatesystem or the hydroquinone (HQJ-ascorbate system, had been addedto the Tris buffer, Hill reaction activity was unaffected. Hill reaction activity of Tris-washed chloroplasts recoveredup to 70% of the initial level by re-washing the chloroplastswith a preparation medium containing theabove reducing reagents. Photobleaching of carotenoid and chlorophyll is characteristicof Tris-washed chloroplasts. However, reactivated chloroplastsshowed no photobleaching as in the case with intact chloroplasts. (Received April 20, 1970; ) 相似文献
7.
Cell-free Studies on the Regulation of the Arabinose Operon 总被引:17,自引:0,他引:17
A DNA directed, cell-free system which synthesized L-ribulokinase coded by the L-arabinose operon ara OIBAD, has been developed. L-arabinose but not the araC gene product is required for the expression of this operon and, in addition, cyclic AMP and guanosine tetraphosphate are needed for optimal synthesis. 相似文献
8.
LINDA L. PIFER 《The Journal of eukaryotic microbiology》1989,36(1):44S-46S
Pneumocystis carinii-specitic immune complexes were detected by immunoblot and enzyme-linked immunosorbent assay (ELISA) in 53% of sera from Acquired Immunodeficiency Syndrome (AIDS) patients with P. carinii pneumonia (PCP). Resolution of glycoprotein antigenemia (50–55 kd = dominant species) appears to correlate with successful PCP drug therapy and recovery. An epitope map has been constructed from im-munoblots of P. carinii hydrolysates and from human and murine scrum containing P. carinii antigens. 相似文献
9.
10.