全文获取类型
收费全文 | 211篇 |
免费 | 16篇 |
国内免费 | 1篇 |
出版年
2014年 | 7篇 |
2013年 | 3篇 |
2012年 | 4篇 |
2011年 | 3篇 |
2010年 | 6篇 |
2009年 | 4篇 |
2008年 | 6篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 10篇 |
1993年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1974年 | 2篇 |
1970年 | 3篇 |
1966年 | 6篇 |
1964年 | 2篇 |
1961年 | 2篇 |
1959年 | 11篇 |
1958年 | 7篇 |
1957年 | 12篇 |
1956年 | 8篇 |
1955年 | 6篇 |
1954年 | 5篇 |
1953年 | 9篇 |
1952年 | 2篇 |
1951年 | 8篇 |
1950年 | 6篇 |
1949年 | 4篇 |
1947年 | 1篇 |
1934年 | 1篇 |
1931年 | 1篇 |
排序方式: 共有228条查询结果,搜索用时 15 毫秒
71.
72.
73.
74.
COLE KS 《Annals of the New York Academy of Sciences》1957,65(6):658-662
75.
76.
77.
ABSTRACT. Three acidic proteins (42 kD, 43 kD and 50 kD) were present in unusually high concentrations in cortical preparations of the Tetrahymena pattern mutant broadened cortical domains (bcd). Antisera to the 42-kD and 50-kD proteins bound to discharging mucocysts and food vacuole contents in both wild-type and mutant cells. Subsequent analysis revealed that bcd mutant cell pellicles possess five times more "docked" mucocysts than their wild-type counterparts. 相似文献
78.
Differential Inactivation of Lymphocytes and Bone Marrow Stem Cells by Heterologous Anti-mouse γ-Globulin Serum 总被引:2,自引:0,他引:2
THE principal obstacle to the effective and widespread clinical application of allogeneic bone marrow transplantation, in the treatment of certain immunological deficiency diseases and leukaemia, is the occurrence of graft versus host (GVH) disease1–3. This syndrome, resulting from donor cell-mediated immunological reactions against tissue antigens of the host, probably results from the presence of mature, immunologically reactive cells in the marrow inoculum, derived either adventitiously from, the circulating blood4 or as residents in the marrow. If these reactive cells could be separated out by physical means (compare ref. 5) or be inactivated specifically, still retaining the viability of the marrow stem cells, it should be possible to preclude at will the occurrence of the often fatal GVH disease, following allogeneic bone marrow transplantation. 相似文献
79.
Gus Koerbin Jillian R Tate Julie Ryan Graham RD Jones Ken A Sikaris David Kanowski Maxine Reed Janice Gill George Koumantakis Tina Yen Andrew St John Peter E Hickman Aaron Simpson Peter Graham 《The Clinical biochemist. Reviews / Australian Association of Clinical Biochemists》2014,35(4):203-211
Harmonisation of reference intervals for routine general chemistry analytes has been a goal for many years. Analytical bias may prevent this harmonisation. To determine if analytical bias is present when comparing methods, the use of commutable samples, or samples that have the same properties as the clinical samples routinely analysed, should be used as reference samples to eliminate the possibility of matrix effect. The use of commutable samples has improved the identification of unacceptable analytical performance in the Netherlands and Spain. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has undertaken a pilot study using commutable samples in an attempt to determine not only country specific reference intervals but to make them comparable between countries. Australia and New Zealand, through the Australasian Association of Clinical Biochemists (AACB), have also undertaken an assessment of analytical bias using commutable samples and determined that of the 27 general chemistry analytes studied, 19 showed sufficiently small between method biases as to not prevent harmonisation of reference intervals. Application of evidence based approaches including the determination of analytical bias using commutable material is necessary when seeking to harmonise reference intervals. 相似文献
80.
CHRISTOPHER T. SOLOMON STEPHEN R. CARPENTER JONATHAN J. COLE MICHAEL L. PACE 《Freshwater Biology》2008,53(1):42-54
1. Secondary production of benthic invertebrates in lakes is supported by current autochthonous primary production, and by detritus derived from a combination of terrestrial inputs and old autochthonous production from prior seasons. We quantified the importance of these two resources for the dominant benthic insects in Crampton Lake, a 26 ha, clear-water system.
2. Daily additions of NaH13 CO3 to the lake caused an increase in the stable carbon isotope ratios ( δ 13 C) of the current primary production of phytoplankton and periphyton. We measured the response of four insect groups (taxon-depth combinations) to this manipulation, quantifying their current autochthony (% reliance on current autochthonous primary production) by fitting dynamic mixing models to time series of insect δ 13 C.
3. The δ13 C of all four groups increased in response to the manipulation, although the magnitude of response differed by taxon and by depth, indicating differences in current autochthony. Odonate larvae (Libellulidae and Corduliidae) collected at 1.5 m depth derived 75% of their C from current autochthonous primary production. Chironomid larvae collected at 1.5, 3.5 and 10 m depths derived, respectively, 43%, 39% and 17% of their C from current autochthonous primary production.
4. Both taxon-specific diet preferences and depth-specific differences in resource availability may contribute to differences in current autochthony. Our results demonstrate significant but incomplete support of insect production by current autochthony, and indicate that allochthonous inputs and old autochthonous detritus support a substantial fraction (25–83%) of insect production. 相似文献
2. Daily additions of NaH
3. The δ
4. Both taxon-specific diet preferences and depth-specific differences in resource availability may contribute to differences in current autochthony. Our results demonstrate significant but incomplete support of insect production by current autochthony, and indicate that allochthonous inputs and old autochthonous detritus support a substantial fraction (25–83%) of insect production. 相似文献