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排序方式: 共有303条查询结果,搜索用时 62 毫秒
31.
Fathi Moussa Pascale Chretie Pierre Dubois Laurence Chuniaud Michelle Dessante Fran ois Trivin Pierre-Yves Sizaret Viatcheslav Agafonov Ren C olin Henri Szwarc Virginie Greugny Claude Fabre Andr Rassat 《Fullerenes, Nanotubes and Carbon Nanostructures》1995,3(3):333-342
In order to check its possible acute toxicity, C60 was incorporated into living human phagocytes. It was observed that C60 has no influence on the survival of human leukocytes. 相似文献
32.
Catherine Fernandez Yogan Monnier Elena Ormeño Virginie Baldy Stéphane Greff Vanina Pasqualini Jean-Philippe Mévy Anne Bousquet-Mélou 《Journal of chemical ecology》2009,35(8):970-979
We investigated changes in the occurrence of allelochemicals from leachates of different Pinus halepensis organs taking into account the stages of pine stand age (i.e., young < 15-years-old, middle age ± 30-years, and old > 60-years-old).
GC-MS analysis of aqueous extracts revealed approx. 59 components from needles and roots. The major constituents were divided
into different phytochemical groups—phenolics (50%), fatty acids (44%), and terpenoids. Further analyses were carried out
to characterize the distribution of allelochemicals in different organs and P. halepensis successional stages. Roots and needles had two distinct chemical profiles, while needle leachates were composed mainly of
oxygenated terpenoids (e.g., α-eudesmol, α-cadinol, and α-terpineol). Roots mainly contained fatty acids. Needles from young
pine stands had the highest content of monoterpenes, suggesting their role as potential allelochemicals that could help young
pine stands to establish. Pooling the different functional chemical groups showed that needles and, to a lesser extent, old
roots, had higher chemical diversity than the roots of young and medium-aged pines. The highest diversity in phenolic constituents
and fatty acids was in young needles (Dchem = 2.38). Finally, caffeic acid, a compound that has allelopathic properties was found in aqueous extracts at high concentrations
in both young needles and old roots. The role of this compound in mediation of biological interactions in P. halepensis ecosystem functioning is discussed. 相似文献
33.
Lennart Bunch Prof. Darryl S. Pickering Prof. Thierry Gefflaut Prof. Virginie Vinatier Dr. Virgil Helaine Ahmad Amir Birgitte Nielsen Anders A. Jensen Prof. 《ChemMedChem》2009,4(11):1925-1929
Subtype‐selective ligands are of great interest to the scientific community, as they provide a tool for investigating the function of one receptor or transporter subtype when functioning in its native environment. Several 4‐substituted (S)‐glutamate (Glu) analogues were synthesized, and altogether this approach has provided important insight into the structure–activity relationships (SAR) for ionotropic and metabotropic glutamate receptors (iGluRs and mGluRs), as well as the excitatory amino acid transporters (EAATs). In this work, three 4,4‐disubstituted Glu analogues 1 – 3 , which are hybrid structures of important 4‐substituted Glu analogues 4 – 8 , were investigated at iGluRs and EAATs. Collectively, their pharmacological profiles add new and valuable information to the SAR for the iGluRs and EAAT1–3. 相似文献
34.
Influence of baking time and matrix effects on the detection of milk allergens in cookie model food system by ELISA 总被引:1,自引:0,他引:1
Milk allergens are common allergens occurring in foods, therefore raising concern in allergic consumers. Enzyme-linked immunosorbent assay (ELISA) is, to date, the method of choice for the detection of food allergens by the food industry although, the performance of ELISA might be compromised when severe food processing techniques are applied to allergen-containing foods. In this paper we investigated the influence of baking time on the detection of milk allergens by using commercial ELISA kits. Baked cookies were chosen as a model food system and experiments were set up to study the impact of spiking a matrix food either before, or after the baking process. Results revealed clear analytical differences between both spiking methods, which stress the importance of choosing appropriate spiking methodologies for method validation purposes. Finally, since the narrow dynamic range of quantification of ELISA implies that dilution of samples is required, the impact of sample dilution on the quantitative results was investigated. All parameters investigated were shown to impact milk allergen detection by means of ELISA. 相似文献
35.
36.
ABSTRACT Thermites are energetic composites made of metal and oxidizer particles that react according to an exothermic reaction and release large amounts of energy. Many possible metal and oxidizer couples exist in the literature. Here, the performance of the aluminum reducing metal and tin (IV) oxide (SnO2) combination was reported as a function of the fuel/oxidizer mass ratio. The Al/SnO2 energetic composite, in stoichiometric conditions, was insensitive to impact, sensitive to friction and extremely sensitive to electrostatic discharge. The combustion velocity was determined to be close to 600 m/s. Changing the stoichiometry affected both the sensitivity thresholds to the friction test (160 N to > 360 N) and flame propagation velocity (480–588 m/s) of the Al/SnO2 composite. These results are reported for the first time. 相似文献
37.
38.
The tragic events at Grenfell Tower in 2017, involving a combustible façade system, have raised concerns regarding the fire risk that these systems pose. In this series of articles, so far published, fire development inside the initial apartment has been investigated using an appropriate computational fluid dynamics (CFD) model. Several scenarios including different fire sources and ventilation conditions were addressed. Fire propagation through the window to the external façade and to higher apartments was modelled. This model was validated by comparing the numerical results with the visual observations reported in the Grenfell Inquiry. A CFD model of the complete east face of the Grenfell Tower was then created. This paper details CFD modelling of the complete Grenfell Tower façade during the late horizontal phase of fire spread. As the physics of lateral flame spread is different from that for upward flame spread, it is important to assess the validity of the model, thus far developed, for this configuration. Fire propagation over the whole façade is modelled and compared with observations from the real disaster. This provides a better understanding of its fire behaviour and of the contribution of architectural details and their impact on fire spread. 相似文献
39.
Partial Sperm beta1 Integrin Subunit Deletion Proves Its Involvement in Mouse Gamete Adhesion/Fusion
Virginie Barraud-Lange Cme Ialy-Radio Cline Chalas Isabelle Holtzmann Jean-Philippe Wolf Sandrine Barbaux Ahmed Ziyyat 《International journal of molecular sciences》2020,21(22)
We have previously shown, using antibodies, that the sperm alpha6beta1 integrin is involved in mouse gamete fusion in vitro. Here we report the conditional knockdown of the sperm Itgb1 gene. It induced a drastic failure of sperm fusogenic ability with sperm accumulation in the perivitelline space of in vitro inseminated oocytes deleted or not for the Itgb1 gene. These data demonstrate that sperm, but not oocyte, beta1 integrin subunit is involved in gamete adhesion/fusion. Curiously, knockdown males were fertile in vivo probably because of the incomplete Cre-mediated deletion of the sperm Itgb1 floxed gene. Indeed, this was shown by Western blot analysis and confirmed by both the viability and litter size of pups obtained by mating partially sperm Itgb1 deleted males with females producing completely deleted Itgb1 oocytes. Because of the total peri-implantation lethality of Itgb1 deletion in mice, we assume that sperm that escaped the Itgb1 excision seemed to be preferentially used to fertilize in vivo. Here, we showed for the first time that the deletion, even partial, of the sperm Itgb1 gene makes the sperm unable to normally fertilize oocytes. However, to elucidate the question of the essentiality of its role during fertilization, further investigations using a mouse expressing a recombinase more effective in male germ cells are necessary. 相似文献
40.