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排序方式: 共有951条查询结果,搜索用时 15 毫秒
941.
Fotini A. Koutroumpa Bruno Vincent Géraldine Roux-Morabito Carine Martin François Lieutier 《Annals of Forest Science》2008,65(7):707-707
942.
Vaudry D Falluel-Morel A Leuillet S Vaudry H Gonzalez BJ 《Science (New York, N.Y.)》2003,300(5625):1532-1534
The proper development of the central nervous system depends upon a finely tuned balance between cell proliferation and programmed cell death (PCD). Although PCD was initially believed to depend solely on the inability of certain neurons to obtain access to a limited supply of trophic factors, it has become apparent that the local production of death signals is also critical. In this Viewpoint, we discuss several pathways implicated in the survival of cerebellar granule cells- both pathways that protect from apoptosis and pathways that promote apoptosis-and describe how these disparate pathways converge on the final common mediators of PCD. Information on other important pathways implicated in granule cell survival may be found in the Connections Maps. 相似文献
943.
Buyse J Swennen Q Niewold TA Klasing KC Janssens GP Baumgartner M Goddeeris BM 《Veterinary immunology and immunopathology》2007,118(1-2):154-159
The objective of the present study was to evaluate the potential effects of dietary L-carnitine supplementation on acute phase protein response upon a lipopolysaccharide (LPS) challenge of male broiler chickens receiving a commercial broiler diet supplemented with 15 or 100 mg L-carnitine/kg or an unsupplemented (control) diet from 14 days of age onwards. At 28 days of age, eight chickens per dietary treatment were weighed and subcutaneously injected with 300 microg LPS from E. coli (100 microg LPS/ml saline) or 3 ml saline (unsupplemented group only). During the next 10 days, blood samples were taken repeatedly and analysed for their hemopexin (HX) and alpha-1 acid glycoprotein (AGP) levels. Extra dietary L-carnitine did not affect broiler performance. At day 1 postinjection, plasma HX and AGP levels were significantly increased in all treatment groups. However, the elevations in circulating HX and AGP levels were more pronounced in the L-carnitine supplemented chickens, especially in the 100mg L-carnitine group. It is concluded that extra L-carnitine in the diet of broiler chickens enhances or advances the acute phase protein response. The exact mode of action needs to be elucidated but seems to be consistent with a glucocorticoid mimicking effect. 相似文献
944.
Bruno Lopes da Silva Ferrette Rui Coelho Victor Marten Peddemors Jennifer R. Ovenden Bruno Alexandre De Franco Claudio Oliveira Fausto Foresti Fernando Fernandes Mendonça 《水产资源保护:海洋与淡水生态系统》2021,31(9):2348-2368
- Extreme climate changes during the Cenozoic Era strengthened different biogeographical barriers that decreased the connectivity among populations, triggering lineage diversification of different species worldwide.
- The mitochondrial DNA control region was employed to explore the phylogeography of Sphyrna zygaena, a globally distributed species threatened by unsustainable, illegal, unreported and unregulated fisheries triggered by the international shark fin trade. It is listed as ‘Vulnerable’ by the IUCN Red List and its trade is regulated by CITES Appendix II.
- Only 13 haplotypes were found with low genetic diversity levels (hd = 0.686 ± 0.014; π = 0.00206 ± 0.00004) compared with other species of the Sphyrnidae family. The species has a very strong phylogeographic population structure among the Atlantic, Indian and Pacific Oceans (ΦST = 0.79132). Worldwide, there are six distinct populations with some haplotype sharing.
- These populations are probably connected by a stepping-stone dispersal of a small number of migrants per generation from the Indo-Pacific towards the Atlantic. Modelling suggests that S. zygaena diverged into two lineages around 6.96 million years ago which have been isolated in glacial refuges in the Atlantic and Indo-Pacific oceans; and after deglaciation, a population expansion probably permitted secondary contact.
- Conservation plans to establish differentiated management units should be adopted in each of the identified populations. Among these, the Eastern Central Atlantic and West Indo-Pacific are the most important areas for the species considering the historical migration routes that act as a bridge connecting the Atlantic and Indo-Pacific Oceans while the Gulf of Guinea connects the Atlantic populations. Still, further studies are required to know if these populations are also linked with nursery areas for the species.
- The results herein can help to delimit the main evolutionarily significant units to implement effective policies to establish differentiated management units as starting points to genetic monitoring programmes for Sphyrna zygaena.
945.
The hippocampus is crucial for spatial memory formation, yet it does not store long-lasting memories. By combining functional brain imaging and region-specific neuronal inactivation in mice, we identified prefrontal and anterior cingulate cortices as critical for storage and retrieval of remote spatial memories [correction]. Imaging of activity-dependent genes also revealed an involvement of parietal and retrosplenial cortices during consolidation of remote memory. Long-term memory storage within some of these neocortical regions was accompanied by structural changes including synaptogenesis and laminar reorganization, concomitant with a functional disengagement of the hippocampus and posterior cingulate cortex [correction]. Thus, consolidation of spatial memory requires a time-dependent hippocampal-cortical dialogue, ultimately enabling widespread cortical networks to mediate effortful recall and use of cortically stored remote memories independently. 相似文献
946.
Hetz C Bernasconi P Fisher J Lee AH Bassik MC Antonsson B Brandt GS Iwakoshi NN Schinzel A Glimcher LH Korsmeyer SJ 《Science (New York, N.Y.)》2006,312(5773):572-576
Accumulation of misfolded protein in the endoplasmic reticulum (ER) triggers an adaptive stress response-termed the unfolded protein response (UPR)-mediated by the ER transmembrane protein kinase and endoribonuclease inositol-requiring enzyme-1alpha (IRE1alpha). We investigated UPR signaling events in mice in the absence of the proapoptotic BCL-2 family members BAX and BAK [double knockout (DKO)]. DKO mice responded abnormally to tunicamycin-induced ER stress in the liver, with extensive tissue damage and decreased expression of the IRE1 substrate X-box-binding protein 1 and its target genes. ER-stressed DKO cells showed deficient IRE1alpha signaling. BAX and BAK formed a protein complex with the cytosolic domain of IRE1alpha that was essential for IRE1alpha activation. Thus, BAX and BAK function at the ER membrane to activate IRE1alpha signaling and to provide a physical link between members of the core apoptotic pathway and the UPR. 相似文献
947.
948.
Role of gelatinous layer in growth stress generation in tension wood@Bruno Clair$Laboratoire de Mécanique et Génie Civil,Université Montpellier 2,France
@Joseph Gril$Laboratoire de Mécanique et Génie Civil,Université Montpellier 2,France 相似文献
949.
Barnes JW Brown RH Turtle EP McEwen AS Lorenz RD Janssen M Schaller EL Brown ME Buratti BJ Sotin C Griffith C Clark R Perry J Fussner S Barbara J West R Elachi C Bouchez AH Roe HG Baines KH Bellucci G Bibring JP Capaccioni F Cerroni P Combes M Coradini A Cruikshank DP Drossart P Formisano V Jaumann R Langevin Y Matson DL McCord TB Nicholson PD Sicardy B 《Science (New York, N.Y.)》2005,310(5745):92-95
Observations from the Cassini Visual and Infrared Mapping Spectrometer show an anomalously bright spot on Titan located at 80 degrees W and 20 degrees S. This area is bright in reflected light at all observed wavelengths, but is most noticeable at 5 microns. The spot is associated with a surface albedo feature identified in images taken by the Cassini Imaging Science Subsystem. We discuss various hypotheses about the source of the spot, reaching the conclusion that the spot is probably due to variation in surface composition, perhaps associated with recent geophysical phenomena. 相似文献
950.
Andreas Redl Marie Hlne Morel Joëlle Bonicel Bruno Vergnes Stephane Guilbert 《Cereal Chemistry》1999,76(3):361-370
Gluten-glycerol dough was extruded under a variety of processing conditions using a corotating self-wiping twin-screw extruder. Influence of feed rate, screw speed, and barrel temperature on processing parameters (die pressure, product temperature, residence time, specific energy) were examined. Use of flow modeling was successful for describing the evolution of the main flow parameters during processing. Rheological properties of extruded samples exhibited network-like behavior and were characterized and modeled by Cole-Cole distributions. Changes in molecular sizes of proteins during extrusion were measured by chromatography and appeared to be correlated to molecular size between network strands, as derived from the rheological properties of the materials obtained. Depending on operating conditions, extrudates presented very different surface aspects, ranging from very smooth-surfaced extrudates with high swell to completely broken extrudates. The results indicated that extrudate breakup was caused by increasing network density, and some gliadins may have acted as cross-linking agents. Increasing network density resulted in decreasing mobility of polymeric chains, and “protein melt” may no longer have been able to support the strain experienced during extrusion through the die. Increasing network density was reflected in increased plateau modulus and molecular size of protein aggregates. Increasing network structure appeared to be induced by the severity of the thermomechanical treatment, as indicated by specific mechanical energy input and maximum temperature reached. 相似文献