全文获取类型
收费全文 | 224篇 |
免费 | 13篇 |
专业分类
237篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 10篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 5篇 |
2015年 | 18篇 |
2014年 | 28篇 |
2013年 | 21篇 |
2012年 | 22篇 |
2011年 | 15篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 5篇 |
2007年 | 14篇 |
2006年 | 10篇 |
2005年 | 8篇 |
2004年 | 9篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有237条查询结果,搜索用时 10 毫秒
211.
Lo Vasco VR 《Journal of cell communication and signaling》2010,4(3):115-117
For a complex organism, short range signalling is not sufficient to coordinate the behaviour of all cells composing itself.
The response to stimuli is the reprogramming of cell activity (resulting in differentiation, proliferation, stand by or apoptosis
depending on the set of signals). Cells own elaborate and complex systems of proteins that enable them to communicate, including
both secreted signalling molecules and related factors, deriving from relic mechanisms. The intra and intercellular signalling
are actively studied not only to comprehend the basic mechanisms that allowed the evolution of mammals species on earth, but
also because the alteration of one or more of these pathways is recognized to be involved in a crescent number of human diseases,
both degenerative and tumoural. That is, a growing body of evidences suggest that every human disease may be analyzed and
classified by a “signalling disease” point of view. This approach opens new therapeutic perspectives, virtually amplifying
for every single disease the number of therapeutic targets (in terms of both genes and proteins) to upstream and/or downstream,
short and/or long distance proteins interacting with the altered molecule, thus individuating many other targets to which
act upon. 相似文献
212.
Dorella FA Estevam EM Pacheco LG Guimarães CT Lana UG Gomes EA Barsante MM Oliveira SC Meyer R Miyoshi A Azevedo V 《Applied and environmental microbiology》2006,72(11):7368-7372
The reporter transposon-based system TnFuZ was used to identify exported proteins of the animal pathogen Corynebacterium pseudotuberculosis. Thirty-four out of 1,500 mutants had detectable alkaline phosphatase (PhoZ) activity. This activity was from 21 C. pseudotuberculosis loci that code for fimbrial and transport subunits and for hypothetical and unknown-function proteins. 相似文献
213.
Photosynthesis Research - In their natural environment, plants are exposed to varying light conditions, which can lead to a build-up of excitation energy in photosystem (PS) II. Non-photochemical... 相似文献
214.
Ana María?Benavides D. Alvaro J.?Duque M.Email author Joost?F.?Duivenvoorden Alejandra?Vasco Ricardo?Callejas 《Biodiversity and Conservation》2005,14(3):739-758
Epiphytism in Colombian Amazonia was described by counting vascular epiphytes in thirty 0.025-ha (5 × 50 m) plots, well-distributed over the main landscape units in the middle Caquetá area of Colombian Amazonia. Each plot was directly adjacent to a 0.1-ha plot at which the species composition of trees and lianas (diameter at breast height (DBH) 2.5 cm) had been recorded 3 years earlier. The purpose of the study was to explore abundance, diversity, and distribution of epiphytes between the principal landscape units. A total of 6129 individual vascular epiphytes were recorded belonging to 27 families, 73 genera, and 213 species (which included 59 morpho-species). Araceae, Orchidaceae, and Bromeliaceae were the most speciose and abundant families. A total of 2763 phorophytes were registered, 1701 (62%) of which with DBH 2.5 cm. About 40–60% of the woody plants with DBH 2.5 cm carried epiphytes, which points at low phorophyte limitation throughout all landscapes. Epiphytism was concentrated on stem bases. Just as trees, epiphyte species assemblages were well associated with the main landscapes. Contrary to trees, however, epiphyte abundance and diversity (species richness, Fishers alpha index) hardly differed between the landscapes. This calls for caution when explanations for distribution and dynamics of tree species are extrapolated to growth forms with a totally different ecology. 相似文献
215.
The aim of the present work was to study parasitological, molecular, and genetic aspects in descendants of crossbreedings between a totally resistant Biomphalaria tenagophila strain (Taim, RS) and another one highly susceptible (Joinville, SC) to Schistosoma mansoni. Descendants F1 and F2 were submitted to S. mansoni infection (LE strain). The susceptibility rates for individuals from Group F1 were 0 to 0.6%, and from Group F2 was 7.2%. The susceptible individuals from Group F2 discharged a lower number of cercariae, when compared with the susceptible parental group, and in 2 out of 9 positive snails the cercarial elimination was discontinued. In order to identify genetic markers associated with resistance the genotype of parental snails and their offspring F1 and F2 were analyzed by means of the randomly amplified polymorphic DNA method. Nevertheless, it was not possible to detect any marker associated to resistance, but the results showed that in the mentioned species the resistance character is determined by two dominant genes. 相似文献
216.
Guo-Qiang Bi Vadim Bolshakov Guojun Bu Catherine M Cahill Zhou-Feng Chen Graham L Collingridge Robin L Cooper Jens R Coorssen Alaa El-Husseini Vasco Galhardo Wen-Biao Gan Jianguo Gu Kazuhide Inoue John Isaac Koichi Iwata Zhengping Jia Bong-Kiun Kaang Mikito Kawamata Satoshi Kida Eric Klann Tatsuro Kohno Min Li Xiao-Jiang Li John F MacDonald Karim Nader Peter V Nguyen Uhtaek Oh Ke Ren John C Roder Michael W Salter Weihong Song Shuzo Sugita Shao-Jun Tang Yuanxiang Tao Yu Tian Wang Newton Woo Melanie A Woodin Zhen Yan Megumu Yoshimura Ming Xu Zao C Xu Xia Zhang Mei Zhen Min Zhuo 《Molecular pain》2006,2(1):1-22
Understanding basic neuronal mechanisms hold the hope for future treatment of brain disease. The 1st international conference on synapse, memory, drug addiction and pain was held in beautiful downtown Toronto, Canada on August 21–23, 2006. Unlike other traditional conferences, this new meeting focused on three major aims: (1) to promote new and cutting edge research in neuroscience; (2) to encourage international information exchange and scientific collaborations; and (3) to provide a platform for active scientists to discuss new findings. Up to 64 investigators presented their recent discoveries, from basic synaptic mechanisms to genes related to human brain disease. This meeting was in part sponsored by Molecular Pain, together with University of Toronto (Faculty of Medicine, Department of Physiology as well as Center for the Study of Pain). Our goal for this meeting is to promote future active scientific collaborations and improve human health through fundamental basic neuroscience researches. The second international meeting on Neurons and Brain Disease will be held in Toronto (August 29–31, 2007). 相似文献
217.
Quésia S. Damaceno Jaqueline P. Souza Jacques R. Nicoli Raquel L. Paula Gabriela B. Assis Henrique C. Figueiredo Vasco Azevedo Flaviano S. Martins 《Probiotics and antimicrobial proteins》2017,9(4):371-379
Several studies have demonstrated a diversity of bacterial species in human milk, even in aseptically collected samples. The present study evaluated potential probiotic bacteria isolated from human milk and associated maternal variables. Milk samples were collected from 47 healthy women and cultured on selective and universal agar media under aerobic and anaerobic conditions. Bacterial isolates were counted and identified by Biotyper Matrix-Assisted Laser Desorption Ionization–Time of Flight mass spectrometry and then tested for probiotic properties. Total bacteria in human milk ranged from 1.5 to 4.0 log10 CFU/mL. The higher bacterial counts were found in colostrum (mean = 3.9 log10 CFU/mL, 95% CI 3.14–4.22, p = 0.00001). The most abundant species was Staphylococcus epidermidis (n = 76). The potential probiotic candidates were Lactobacillus gasseri (n = 4), Bifidobacterium breve (n = 1), and Streptococcus salivarius (n = 4). Despite the small sample size, L. gasseri was isolated only in breast milk from mothers classified into a normal weight range and after a vaginally delivered partum. No potential probiotics showed antagonism against pathogens, but all of them agglutinated different pathogens. Nine bacterial isolates belonging to the species L. gasseri, B. breve, and S. salivarius were selected as potential probiotics. The present study confirms the presence in breast milk of a bacterial microbiota that could be the source of potential probiotic candidates to be used in the formula of simulated maternal milk. 相似文献
218.
Rommel Thiago Jucá Ramos Artur Silva Adriana Ribeiro Carneiro Anne Cybelle Pinto Siomar de Castro Soares Anderson Rodrigues Santos Sintia Silva Almeida Luis Carlos Guimar?es Flávia Figueira Aburjaile Eudes Guilherme Vieira Barbosa Fernanda Alves Dorella Flávia Souza Rocha Louise Teixeira Cerdeira Maria Silvanira Barbosa Andreas Tauch Judy Edman Sharon Spier Anderson Miyoshi Maria Paula Cruz Schneider Vasco Azevedo 《Journal of bacteriology》2012,194(23):6620-6621
The bacterium Corynebacterium pseudotuberculosis is of major veterinary importance because it affects livestock, particularly sheep, goats, and horses, in several countries, including Australia, Brazil, the United States, and Canada, resulting in significant economic losses. In the present study, we describe the complete genome of the Corynebacterium pseudotuberculosis Cp316 strain, biovar equi, isolated from the abscess of a North American horse. 相似文献
219.
Henrique Borges da Silva Raíssa Fonseca Alexandra dos Anjos Cassado érika Machado de Salles Maria Nogueira de Menezes Jean Langhorne Katia Regina Perez Iolanda Midea Cuccovia Bernhard Ryffel Vasco M. Barreto Cláudio Romero Farias Marinho Silvia Beatriz Boscardin José Maria álvarez Maria Regina D’Império-Lima Carlos Eduardo Tadokoro 《PLoS pathogens》2015,11(2)
Dendritic cells (DCs) are phagocytes that are highly specialized for antigen presentation. Heterogeneous populations of macrophages and DCs form a phagocyte network inside the red pulp (RP) of the spleen, which is a major site for the control of blood-borne infections such as malaria. However, the dynamics of splenic DCs during Plasmodium infections are poorly understood, limiting our knowledge regarding their protective role in malaria. Here, we used in vivo experimental approaches that enabled us to deplete or visualize DCs in order to clarify these issues. To elucidate the roles of DCs and marginal zone macrophages in the protection against blood-stage malaria, we infected DTx (diphtheria toxin)-treated C57BL/6.CD11c-DTR mice, as well as C57BL/6 mice treated with low doses of clodronate liposomes (ClLip), with Plasmodium chabaudi AS (Pc) parasites. The first evidence suggesting that DCs could contribute directly to parasite clearance was an early effect of the DTx treatment, but not of the ClLip treatment, in parasitemia control. DCs were also required for CD4+ T cell responses during infection. The phagocytosis of infected red blood cells (iRBCs) by splenic DCs was analyzed by confocal intravital microscopy, as well as by flow cytometry and immunofluorescence, at three distinct phases of Pc malaria: at the first encounter, at pre-crisis concomitant with parasitemia growth and at crisis when the parasitemia decline coincides with spleen closure. In vivo and ex vivo imaging of the spleen revealed that DCs actively phagocytize iRBCs and interact with CD4+ T cells both in T cell-rich areas and in the RP. Subcapsular RP DCs were highly efficient in the recognition and capture of iRBCs during pre-crisis, while complete DC maturation was only achieved during crisis. These findings indicate that, beyond their classical role in antigen presentation, DCs also contribute to the direct elimination of iRBCs during acute Plasmodium infection. 相似文献
220.
Thomas W. A. Braukmann Natalia V. Ivanova Sean W. J. Prosser Vasco Elbrecht Dirk Steinke Sujeevan Ratnasingham Jeremy R. de Waard Jayme E. Sones Evgeny V. Zakharov Paul D. N. Hebert 《Molecular ecology resources》2019,19(3):711-727
Although DNA metabarcoding is an attractive approach for monitoring biodiversity, it is often difficult to detect all the species present in a bulk sample. In particular, sequence recovery for a given species depends on its biomass and mitome copy number as well as the primer set employed for PCR. To examine these variables, we constructed a mock community of terrestrial arthropods comprised of 374 species. We used this community to examine how species recovery was impacted when amplicon pools were constructed in four ways. The first two protocols involved the construction of bulk DNA extracts from different body segments (Bulk Abdomen, Bulk Leg). The other protocols involved the production of DNA extracts from single legs which were then merged prior to PCR (Composite Leg) or PCR‐amplified separately (Single Leg) and then pooled. The amplicons generated by these four treatments were then sequenced on three platforms (Illumina MiSeq, Ion Torrent PGM and Ion Torrent S5). The choice of sequencing platform did not substantially influence species recovery, although the Miseq delivered the highest sequence quality. As expected, species recovery was most efficient from the Single Leg treatment because amplicon abundance varied little among taxa. Among the three treatments where PCR occurred after pooling, the Bulk Abdomen treatment produced a more uniform read abundance than the Bulk Leg or Composite Leg treatment. Primer choice also influenced species recovery and evenness. Our results reveal how variation in protocols can have substantial impacts on perceived diversity unless sequencing coverage is sufficient to reach an asymptote. 相似文献