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Laure-Emmanuelle Zaragosi Brigitte Wdziekonski Kevin Le Brigand Phi Villageois Bernard Mari Rainer Waldmann Christian Dani Pascal Barbry 《Genome biology》2011,12(7):R64
Background
In severe obesity, as well as in normal development, the growth of adipose tissue is the result of an increase in adipocyte size and numbers, which is underlain by the stimulation of adipogenic differentiation of precursor cells. A better knowledge of the pathways that regulate adipogenesis is therefore essential for an improved understanding of adipose tissue expansion. As microRNAs (miRNAs) have a critical role in many differentiation processes, our study aimed to identify the role of miRNA-mediated gene silencing in the regulation of adipogenic differentiation. 相似文献2.
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Implantation of polymer scaffolds seeded with neural stem cells in a canine spinal cord injury model
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Andrew Wilby La Pham Lan Kong Luen Heong Nguyen Phi Dieu Huyen Nguyen Huu Quang Nguyen Viet Minh Matt. B Thomas 《Ecosystems》2006,9(4):538-549
Declining biodiversity in agro-ecosystems, caused by intensification of production or expansion of monocultures, is associated
with the emergence of agricultural pests. Understanding how land-use and management control crop-associated biodiversity is,
therefore, one of the key steps towards the prediction and maintenance of natural pest-control. Here we report on relationships
between land-use variables and arthropod community attributes (for example, species diversity, abundance and guild structure)
across a diversification gradient in a rice-dominated landscape in the Mekong delta, Vietnam. We show that rice habitats contained
the most diverse arthropod communities, compared with other uncultivated and cultivated land-use types. In addition, arthropod
species density and Simpson’s diversity in flower, vegetable and fruit habitats was positively related to rice cover in the
local landscape. However, across the landscape as a whole, reduction in heterogeneity and the amount of uncultivated cover
was associated, generally, with a loss of diversity. Furthermore, arthropod species density in tillering and flowering stages
of rice was positively related to crop and vegetation richness, respectively, in the local landscape. Differential effects
on feeding guilds were also observed in rice-associated communities with the proportional abundance of predators increasing
and the proportional abundance of detritivores decreasing with increased landscape rice cover. Thus, we identify a range of
rather complex, sometimes contradictory patterns concerning the impact of rice cover and landscape heterogeneity on arthropod
community attributes. Importantly, we conclude that that land-use change associated with expansion of monoculture rice need
not automatically impact diversity and functioning of the arthropod community. 相似文献
5.
Thi My Lien Do Anh Vu Truong Thi Nga Vo Travis G. Pinnock Lawrence M. Pratt Dominique Guillaume Kim Phi Phung Nguyen 《Phytochemistry letters》2013,6(4):544-551
Boerhaavia diffusa L. is used in the traditional medicine of several Asian countries. The isolation and identification of five new compounds, together with 11 known compounds, from the ethyl acetate extract of the aerial part of B. diffusa grown Vietnam is reported. The structure of the new compounds was established by 1D and 2D NMR spectroscopy, and high resolution ESI-MS analysis. New compounds are two rotenoids: 9,11-dihydroxy-6,10-dimethoxy[1]benzopyrano[3,4-b][1]benzopyran-12(6H)-one (boeravinone P, 3) and 3-[2-(β-d-glucopyranosyloxy)-3-hydroxyphenyl]-5-hydroxy-2-hydroxymethyl-7-methoxy-6-methyl-4H-1-benzopyran-4-one (boeravinone Q, 9), an atropisomeric mixture of two rotenoid glycosides (3′,5-dihydroxy-2-hydroxymethyl-7-methoxy-6-methylisoflavone 2′-O-β-d-glucopyranoside, 11), a sesquiterpene lactone (4,10-dihydroxy-8-methoxyguai-7(11)-en-8,12-olide, 5) and a new phenylpropanoid glycoside (boerhaavic acid, 15). 相似文献
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This paper presents the dynamic modeling of a flexible tail for a robotic fish. For this purpose firstly, the flexible tail was simplified as a slewing beam actuated by a driving moment. The governing equation of the flexible tail was derived by using the Euler-Bernoulli theory. In this equation, the resistive forces were estimated as a term analogous to viscous damping. Then, the modal analysis method was applied in order to derive an analytical solution of the governing equation, by which the relationship between the driving moment and the lateral movement of the flexible tail was described. Finally, simulations and experiments were carried out and the results were compared to verify the accuracy of the dynamic model. It was proved that the dynamic model of a fish robot with a flexible tail fin well explains the real behavior of robotic fish in underwater environment. 相似文献
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Intercellular communication in the rat anterior pituitary gland: an in vivo and in vitro study 总被引:3,自引:1,他引:2 下载免费PDF全文
The concept of "stimulus-secretion coupling" suggested by Douglas and co-workers to explain the events related to monamine discharge by the adrenal medulla (5, 7) may be applied to other endocrine tissues, such as adrenal cortex (36), pancreatic islets (4), and magnocellular hypothalamic neurons (6), which exhibit a similar ion-dependent process of hormone elaboration. In addition, they share another feature, that of joining neighbor cells via membrane junctions (12, 26, and Fletcher, unpublished observation). Given this, and the reports that hormone secretion by the pars distalis also involves a secretagogue-induced decrease in membrane bioelectric potential accompanied by a rise in cellular [Ca++] (27, 34, 41), it was appropriate to test the possibility that cells of the anterior pituitary gland are united by junctions. 相似文献
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Dong Hee Lee In Chul Lee Kook Jin Kim Dong Su Kim Hyung Jin Na In-Jung Lee Sang-Mo Kang Hyung-Woo Jeon Phi Yen Le Jae-Heung Ko 《Journal of Plant Biology》2014,57(2):106-116
Gibberellin (GA), a plant hormone, is involved in many aspects of plant growth and development both in vegetative and reproductive phases. GA2-oxidase plays a key role in the GA catabolic pathway to reduce bioactive GAs. We produced transgenic Arabidopsis plants expressing GA2-oxidase 4 (AtGA2ox4) under the control of a senescenceassociated promoter (SEN1). As we hypothesized, transgenic plants (SEN1::AtGA2ox4) exhibited a dominant semi-dwarf phenotype with a decrease of bioactive GAs (e.g., GA4 and GA1) up to two-fold compared to control plants. Application of bioactive GA3 resulted in increased shoot length, indicating that the GA signaling pathway functions normally in the SEN1::AtGA2ox4 plants. Expressions of other members of GA2-oxidase family, such as AtGA2ox1, AtGA2ox3, AtGA2ox6, and AtGA2ox8, were decreased slightly in the flower and silique tissues while GA biosynthetic genes (e.g., AtGA20ox1, AtGA20ox2 and AtGA3ox1) were not significantly changed in the SEN::AtGA2ox4 plants. Using proteome profiling (2-D PAGE followed by MALDI-TOF/MS), we identified 29 protein spots that were increased in the SEN1::AtGA2ox4 plants, but were decreased to wild-type levels by GA3 treatment. The majority were found to be involved in photosynthesis and carbon/energy metabolism. Unlike the previous constitutive over-expression of GA2-oxidases, which frequently led to floral deformity and/or loss of fertility, the SEN1::AtGA2ox4 plants retained normal floral morphology and seed production. Accordingly, the expressions of FT and CO genes remained unchanged in the SEN1::AtGA2ox4 plants. Taken together, our results suggest that the dominant dwarf trait carried by SEN1::AtGA2ox4 plants can be used as an efficient dwarfing tool in plant biotechnological applications. 相似文献