全文获取类型
收费全文 | 985篇 |
免费 | 71篇 |
出版年
2023年 | 9篇 |
2022年 | 17篇 |
2021年 | 41篇 |
2020年 | 27篇 |
2019年 | 28篇 |
2018年 | 33篇 |
2017年 | 32篇 |
2016年 | 42篇 |
2015年 | 76篇 |
2014年 | 72篇 |
2013年 | 69篇 |
2012年 | 79篇 |
2011年 | 60篇 |
2010年 | 46篇 |
2009年 | 26篇 |
2008年 | 50篇 |
2007年 | 51篇 |
2006年 | 35篇 |
2005年 | 32篇 |
2004年 | 34篇 |
2003年 | 27篇 |
2002年 | 33篇 |
2001年 | 14篇 |
2000年 | 21篇 |
1999年 | 18篇 |
1998年 | 8篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1985年 | 2篇 |
1980年 | 3篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1960年 | 2篇 |
1927年 | 1篇 |
排序方式: 共有1056条查询结果,搜索用时 859 毫秒
91.
Annemarie MM Vlaar Angela EP Bouwmans Marinus JPG van Kroonenburgh Werner H Mess Selma C Tromp Piet GWM Wuisman Alfons GH Kessels Ania Winogrodzka Wim EJ Weber 《BMC neurology》2007,7(1):28
Background
Parkinson's disease (PD) is the second most common neurodegenerative disorder. As there is no definitive diagnostic test, its diagnosis is based on clinical criteria. Recently transcranial duplex scanning (TCD) of the substantia nigra in the brainstem has been proposed as an instrument to diagnose PD. We and others have found that TCD scanning of substantia nigra duplex is a relatively accurate diagnostic instrument in patients with parkinsonian symptoms. However, all studies on TCD so far have involved well-defined, later-stage PD patients, which will obviously lead to an overestimate of the diagnostic accuracy of TCD. 相似文献92.
Martins Renato T. Brito Janaina Dias-Silva Karina Leal Ceclia G. Leito Rafael P. Oliveira Vivian C. Oliveira-Jnior Jos M. B. de Paula Felipe R. Roque Fabio O. Hamada Neusa Juen Leandro Nessimian Jorge L. Pompeu Paulo S. Hughes Robert M. 《Hydrobiologia》2022,849(10):2281-2298
Hydrobiologia - Stream degradation in Amazonia is outpacing our ability to effectively monitor it for three key reasons: (1) Many changes are cumulative and occur gradually; (2) Scientists have... 相似文献
93.
Martins Renato Tavares de Freitas Silva Rafael Augusto Pinheiro Pinto Valria Arajo Braule Medeiros Adriana Oliveira Brito Laisa Hamada Neusa 《Hydrobiologia》2022,849(16):3531-3544
Hydrobiologia - We used experimental chambers to evaluate the effect of the temperature increasing and microbial conditioning degree on the survival and leaf consumption of two plant species... 相似文献
94.
Bernardes-Engemann Andréa Reis Almeida Marcos de Abreu Bison Ividy Rabello Vanessa Brito de Souza Ramos Mariana Lucy Mesquita Pereira Sandro Antonio Almeida-Paes Rodrigo de Lima Brasil Arthur Willian Zancopé-Oliveira Rosely Maria 《Mycopathologia》2022,187(4):375-384
Mycopathologia - Feline sporotrichosis has emerged as an important public health issue in some countries, especially Brazil. Currently, zoonotic transmission of Sporothrix brasiliensis by domestic... 相似文献
95.
Paulo FP Pimenta Alessandra S Orfano Ana C Bahia Ana PM Duarte Claudia M Ríos-Velásquez Fabrício F Melo Felipe AC Pessoa Giselle A Oliveira Keillen MM Campos Luis Martínez Villegas Nilton Barnabé Rodrigues Rafael Nacif-Pimenta Rejane C Sim?es Wuelton M Monteiro Rogerio Amino Yara M Traub-Cseko José BP Lima Maria GV Barbosa Marcus VG Lacerda Wanderli P Tadei Nágila FC Secundino 《Memórias do Instituto Oswaldo Cruz》2015,110(1):23-47
In the Americas, areas with a high risk of malaria transmission are mainly located in
the Amazon Forest, which extends across nine countries. One keystone step to
understanding the Plasmodium life cycle in Anopheles species from the Amazon Region
is to obtain experimentally infected mosquito vectors. Several attempts to colonise
Ano- pheles species have been conducted, but with only short-lived success or no
success at all. In this review, we review the literature on malaria transmission from
the perspective of its Amazon vectors. Currently, it is possible to develop
experimental Plasmodium vivax infection of the colonised and field-captured vectors
in laboratories located close to Amazonian endemic areas. We are also reviewing
studies related to the immune response to P. vivax infection of Anopheles aquasalis,
a coastal mosquito species. Finally, we discuss the importance of the modulation of
Plasmodium infection by the vector microbiota and also consider the anopheline
genomes. The establishment of experimental mosquito infections with Plasmodium
falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide
interesting models for studying malaria in the Amazonian scenario is important.
Understanding the molecular mechanisms involved in the development of the parasites
in New World vectors is crucial in order to better determine the interaction process
and vectorial competence. 相似文献
96.
Francinaldo Soares Silva Jefferson Mesquita Brito Benedita Maria Costa Neta Shelre Emile Pereira Duarte Lobo 《Memórias do Instituto Oswaldo Cruz》2015,110(6):801-803
Hoover Pugedo light traps were modified for use with green and blue-light-emitting
diodes to trap phlebotomine sandflies in northeastern Brazil. A total of 2,267
specimens belonging to eight genera and 15 species were sampled. The predominant
species were Nyssomyia whitmani(34.41%) and Micropygomyia
echinatopharynx(17.25%).The green LED trap prevailed over the blue and
control lights; however, no statistically significant difference could be detected
among the three light sources. Even without statistical significance, we suggest
using LEDs as an attractant for the capture of sandflies because of several
advantages over the conventional method with incandescent lamps. 相似文献
97.
98.
99.
Clare Edwards John Canfield Neil Copes Andres Brito Muhammad Rehan David Lipps Jessica Brunquell Sandy D Westerheide Patrick C Bradshaw 《BMC genetics》2015,16(1)
Background
Little is known about the role of amino acids in cellular signaling pathways, especially as it pertains to pathways that regulate the rate of aging. However, it has been shown that methionine or tryptophan restriction extends lifespan in higher eukaryotes and increased proline or tryptophan levels increase longevity in C. elegans. In addition, leucine strongly activates the TOR signaling pathway, which when inhibited increases lifespan.Results
Therefore each of the 20 proteogenic amino acids was individually supplemented to C. elegans and the effects on lifespan were determined. All amino acids except phenylalanine and aspartate extended lifespan at least to a small extent at one or more of the 3 concentrations tested with serine and proline showing the largest effects. 11 of the amino acids were less potent at higher doses, while 5 even decreased lifespan. Serine, proline, or histidine-mediated lifespan extension was greatly inhibited in eat-2 worms, a model of dietary restriction, in daf-16/FOXO, sir-2.1, rsks-1 (ribosomal S6 kinase), gcn-2, and aak-2 (AMPK) longevity pathway mutants, and in bec-1 autophagy-defective knockdown worms. 8 of 10 longevity-promoting amino acids tested activated a SKN-1/Nrf2 reporter strain, while serine and histidine were the only amino acids from those to activate a hypoxia-inducible factor (HIF-1) reporter strain. Thermotolerance was increased by proline or tryptophan supplementation, while tryptophan-mediated lifespan extension was independent of DAF-16/FOXO and SKN-1/Nrf2 signaling, but tryptophan and several related pyridine-containing compounds induced the mitochondrial unfolded protein response and an ER stress response. High glucose levels or mutations affecting electron transport chain (ETC) function inhibited amino acid-mediated lifespan extension suggesting that metabolism plays an important role. Providing many other cellular metabolites to C. elegans also increased longevity suggesting that anaplerosis of tricarboxylic acid (TCA) cycle substrates likely plays a role in lifespan extension.Conclusions
Supplementation of C. elegans with 18 of the 20 individual amino acids extended lifespan, but lifespan often decreased with increasing concentration suggesting hormesis. Lifespan extension appears to be caused by altered mitochondrial TCA cycle metabolism and respiratory substrate utilization resulting in the activation of the DAF-16/FOXO and SKN-1/Nrf2 stress response pathways.Electronic supplementary material
The online version of this article (doi:10.1186/s12863-015-0167-2) contains supplementary material, which is available to authorized users. 相似文献100.