全文获取类型
收费全文 | 477篇 |
免费 | 32篇 |
国内免费 | 2篇 |
出版年
2022年 | 3篇 |
2021年 | 8篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 16篇 |
2017年 | 8篇 |
2016年 | 6篇 |
2015年 | 13篇 |
2014年 | 15篇 |
2013年 | 15篇 |
2012年 | 39篇 |
2011年 | 32篇 |
2010年 | 17篇 |
2009年 | 12篇 |
2008年 | 26篇 |
2007年 | 25篇 |
2006年 | 21篇 |
2005年 | 18篇 |
2004年 | 17篇 |
2003年 | 17篇 |
2002年 | 20篇 |
2001年 | 21篇 |
2000年 | 8篇 |
1999年 | 20篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 9篇 |
1994年 | 5篇 |
1993年 | 8篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1970年 | 3篇 |
1966年 | 2篇 |
1965年 | 2篇 |
1962年 | 1篇 |
1916年 | 1篇 |
排序方式: 共有511条查询结果,搜索用时 15 毫秒
91.
92.
This paper explains the objectives of organising the symposium ‘The Other North Sea’. A major goal is the submission of the
conclusions and content of this symposium to the North Sea Task Force, an initiative of the Second Conference on the Protection
of the North Sea (London, 1987) which is responsible for preparing a Quality Status Report on the North Sea by mid-1993. The
conclusions and recommendations of the symposium are summarised and presented to the North Sea Task Force in connection with
the preparations for the 1993 Quality Status Report. The paper stresses the need to subdivide the North Sea into areas of
ecological entity and underlines the advantages of using diatom and meiofauna assemblages as indicators for present and past
environmental actors in sediment conditions. A plea is also made for the promotion of research to improve understanding of
disturbance of sensory perception and behaviour as an ecologically relevant early warning signal. The major role of fisheries
in inducing changes of seabird and harbour porpoise populations is highlighted. 相似文献
93.
Eliara Ten Caten Martins Rafaella Zulianello dos Santos Analu Bender dos Santos Pauline Brendler Goettems Fiorin Yana Picinin Sandri Matias Nunes Frizzo Mirna Stela Ludwig Thiago Gomes Heck Magnus Benetti 《Cell stress & chaperones》2018,23(6):1319-1327
Previous studies reported that extracellular HSP72 (eHSP72) correlates with poor prognosis, markers of vascular dysfunction, and the severity of cardiovascular diseases, associated with a systemic oxidative and inflammatory profile. On the other hand, eHSP72 may represent immune-regulatory signaling that is related to exercise benefits, but the association between physical activity levels and eHSP72 levels is not established. Thus, since regular physical activity may avoid oxidative stress and inflammation, we investigate whether detectable levels of eHSP72 in plasma are associated with physical activity and antioxidant enzyme activity levels in hypertensive subjects. Physical activity levels of hypertensive subjects (n?=?140) were measured by tri-axial movement sensor pedometer for 24 h during 5 consecutive days. One day after, blood was collected into heparinized tubes for oxidative stress analyses (catalase—CAT and superoxide dismutase—SOD activities and malondialdehyde levels) or in disodium EDTA tubes for eHSP72 assays. Thus, hypertensive subjects were classified as physically inactive (<?10,000 footsteps/day) or active (>?than 10,000 footsteps/day) and according detectable or not detectable eHSP72 levels in plasma, performing the inactive/eHSP72?, active/eHSP72?, inactive/eHSP72+, and active/eHSP72+ groups. We found that detectable levels of eHSP72 in plasma were associated with physical activity levels and low oxidative stress profile (Higher CAT and SOD activities and low malondialdehyde levels). eHSP72 levels can be used as a biomarker of the amount of physical activity necessary to improve antioxidant defense and thus cardiovascular health in hypertensive subjects. 相似文献
94.
Weilan Li Seung-Yeol Lee In-Kyu Kang Leonid N. Ten Hee-Young Jung 《Journal of microbiology (Seoul, Korea)》2018,56(2):90-96
A Gram-negative, motile, rod-shaped, aerobic bacterial strain, designated S7-2-11T, was isolated from apple orchard soil from Gyeongsangnam-do Province, Republic of Korea, and was characterized taxonomically using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain S7-2-11T belongs to the family Cytophagaceae in phylum Bacteroidetes, and is closely related to Spirosoma luteolum 16F6ET (94.2% identity), Spirosoma knui 15J8-12T (92.7%), and Spirosoma linguale DSM 74T (91.0%). The G + C content of the genomic DNA of strain S7-2-11T was 49.8 mol%. Strain S7-2-11T contained summed feature 3 (C16:1 ω7c/C16:1 ω6c; 35.1%), C16:1 ω5c (22.4%), C15:0 iso (13.9%), and C17:0 iso 3-OH (10.6%) as major cellular fatty acids, and MK-7 as the predominant respiratory quinone. The main polar lipids were phosphatidylethanolamine, an unidentified aminophospholipid, and two unidentified polar lipids. Phenotypic and chemotaxonomic data supported the affiliation of strain S7-2-11T with the genus Spirosoma. The results of physiological and biochemical tests showed the genotypic and phenotypic differentiation of the isolate from recognized Spirosoma species. On the basis of its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain S7-2-11T represents a novel species of the genus Spirosoma, for which the name Spirosoma pomorum sp. nov. is proposed. The type strain is S7-2-11T (= KCTC 52726T = JCM 32130T). 相似文献
95.
Mies M. Güth A. Z. Tenório A. A. Banha T. N. S. Waters L. G. Polito P. S. Taniguchi S. Bícego M. C. Sumida P. Y. G. 《Coral reefs (Online)》2018,37(3):677-689
Coral Reefs - Many species of reef-building corals are mixotrophic, relying on both photoautotrophy performed by their dinoflagellate symbionts and heterotrophy from consumption of zooplankton.... 相似文献
96.
97.
On the power to detect differences between male and female mutation rates for Duchenne muscular dystrophy, using classical segregation analysis and restriction fragment length polymorphisms 总被引:6,自引:2,他引:4 下载免费PDF全文
The power to detect departures from the theoretical proportion of new mutants in X-linked lethal disorders has been analyzed for several types of segregation analysis, including methods based on completely linked restriction fragment length polymorphisms. It is shown that all methods require large sample sizes in order to detect even large differences between male and female mutation rates. Ascertainment bias is shown to have a great effect on the outcome of the segregation analysis. All reviewed studies concerning the proportion of new mutants in Duchenne muscular dystrophy, whether they claimed equality or inequality between the male and female mutation rates, give insufficient evidence because of ascertainment bias and a too low power. An ascertainment bias-free method is given, with the advantage that information from many studies can be combined. By doing so, in the long run, even moderate departures from equality in mutation rates (if present) can be detected. 相似文献
98.
99.
100.
M J Sigal J E Aubin A R Ten Cate S Pitaru 《The journal of histochemistry and cytochemistry》1984,32(8):872-877
The length and extent of the odontoblast cell process in dentine has been the subject of controversy for many years. Here an immunofluorescence technique has been applied at the light microscope level to rat coronal dentine to localize the intracellular components actin and tubulin. Adult rats were perfused with periodate-lysine-paraformaldehyde fixative, teeth were extracted, the molar crowns were demineralized, dehydrated, wax embedded, and 6 micron sections were prepared. The sections were postfixed in -20 degrees C acetone and then incubated with affinity-purified rabbit anti-actin or anti-tubulin antibodies, followed by fluorescein-conjugated goat anti-rabbit immunoglobulin. Intratubular immunofluorescence labeling for tubulin extended to the dentinoenamel junction, whereas labeling for actin, although extending to the dentinoenamel junction, was more prominent in the pulpal third of the rat dentine. Areas in which odontoblast processes are known not to occur, i.e., the atubular dentine, were not labeled by either antibody. The presence of actin- and tubulin-containing structures extending to the dentinoenamel junction is consistent with the hypothesis that the odontoblast process traverses the dentine for up to 3-4 mm, all the way to the dentinoenamel junction. Furthermore, the different staining patterns for actin-containing microfilaments as compared to tubulin-containing microtubules suggest that these two filamentous systems may have different roles in the function of the odontoblast process. 相似文献