全文获取类型
收费全文 | 261篇 |
免费 | 8篇 |
国内免费 | 1篇 |
出版年
2015年 | 1篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 3篇 |
2010年 | 8篇 |
2009年 | 6篇 |
2008年 | 3篇 |
2006年 | 10篇 |
2005年 | 4篇 |
2003年 | 2篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1971年 | 4篇 |
1970年 | 1篇 |
1965年 | 1篇 |
1959年 | 7篇 |
1958年 | 5篇 |
1957年 | 21篇 |
1956年 | 13篇 |
1955年 | 26篇 |
1954年 | 20篇 |
1953年 | 5篇 |
1952年 | 26篇 |
1951年 | 16篇 |
1950年 | 15篇 |
1949年 | 4篇 |
1948年 | 9篇 |
1946年 | 1篇 |
排序方式: 共有270条查询结果,搜索用时 15 毫秒
1.
In this paper the recent population changes of the Wild Boar in different European countries is analysed through the study of hunting statistics. A simultaneous increase in numbers is observed throughout the whole area during the period 1965–1975. From 1975 onwards the population stabilizes itself apart from in peripheral areas like Finland. Potentially favourable factors which play a part in this process are discussed and certain reproductive and dispersive characteristics which favour its invasive behaviour are discussed. 相似文献
2.
3.
4.
5.
6.
7.
JOHN C. BEIER FRED K. ONYANGO JOSEPH K. KOROS MUTALIB RAMADHAN ROSE OGWANG ROBERT A. WIRTZ DAVY K. KOECH CLIFFORD R. ROBERTS 《Medical and veterinary entomology》1991,5(1):71-79
Abstract. The malaria transmission potential of wild, infective Anopheles from western Kenya was evaluated by determining the number of sporozoites transmitted in vitro by salivation when their mouthparts were inserted into capillary tubes containing either sucrose or blood. With sucrose, 86.6% of 102 infective Anopheles transmitted a geometric mean (GM) of 3.84 sporozoites (range 1–34). With blood, 23.1% of 104 infective Anopheles , tested on the day of collection, transmitted a GM of 2.30 sporozoites (range 1–117). For Anopheles held 5 days postcapture before testing with blood, 53.6% of 56 transmitted a GM of 6.04 sporozoites (range 1–420). Transmitting Anopheles contained significantly more salivary gland sporozoites than non-transmitters. No significant differences were detected between Anopheles gambiae Giles sensu lato and Anopheles funestus Giles in sporozoite transmission by individuals with sporozoites in their salivary glands.
Sporozoites were detected microscopically in the salivary duct from heads in 80.3% of 117 infective Anopheles (GM=11.2, range 1–71). Sporozoite detection in mosquito heads by ELISA was 25% less efficient than microscopic detection.
Over 98% of the infective Anopheles transmitted less than twenty-five sporozoites. Transmitted sporozoites represented only about 3% of the total sporozoites in the salivary glands suggesting that sporozoite transmission may be restricted to sporozoites in the salivary duct at the time of feeding. Results are discussed in relation to anti-sporozoite vaccine development. 相似文献
Sporozoites were detected microscopically in the salivary duct from heads in 80.3% of 117 infective Anopheles (GM=11.2, range 1–71). Sporozoite detection in mosquito heads by ELISA was 25% less efficient than microscopic detection.
Over 98% of the infective Anopheles transmitted less than twenty-five sporozoites. Transmitted sporozoites represented only about 3% of the total sporozoites in the salivary glands suggesting that sporozoite transmission may be restricted to sporozoites in the salivary duct at the time of feeding. Results are discussed in relation to anti-sporozoite vaccine development. 相似文献
8.
9.
IMMUNOGLOBULIN polypeptide chains consist of two well defined regions designated the “variable region” and the “constant region”. Whereas great diversity exists in amino-acid sequences of variable regions, the constant regions of a given subclass of heavy chains (CH)* are essentially invariant in sequence1, 2. Exceptions are the allelic forms, such as the rabbit allotypes A14 and A153, 4, where a threonine-alanine interchange occurs in the constant region of γ chains (Appella, Chersi, R. G. M. and Dubiski, in preparation). The markers unique to a chains (for example, A14-A15) are closely linked to allotypic markers at the a locus (a1, a2, a3)3, 4 which seem to be present on four different Ig heavy chain classes (α, γ, ε, µ)5–7. These puzzling observations can be explained if the a locus determinants are variable region markers which reflect genetically controlled differences in some relatively constant residues within the VH region sequences7. 相似文献
10.
Antigens of the Ii System on Lymphocytes 总被引:8,自引:0,他引:8
K. H. SHUMAK ROSE A. RACHKEWICH MARIE C. CROOKSTON J. H. CROOKSTON 《Nature: New biology》1971,231(22):148-149
USUALLY Ii specificity is assigned to cold agglutinins on the basis of their reactions with the red cells of human adults (adult red cells) and newborn infants (cord red cells). Those which react more strongly with adult red cells are said to detect I antigen and are designated anti-I; those which react more strongly with cord red cells are said to detect i antigen and are designated anti-i1,2. We have now found that I and i antigens can be easily detected on lymphocytes. 相似文献