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991.
992.
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
993.
994.
Product development is a collaborative activity more often than ever carried out by distributed design teams. It is critical to determine how sketches are used in such environments in order to improve the design process. Sketches produced by students participating in a collaborative design project of three European Universities are classified according to the intention of the designer when producing a sketch, the level of detail shown in the sketch and the phase when the sketch was produced. The adapted classification system used in this paper helps to analyse type of sketches with most variety of ideas. Furthermore, this paper reviews which type of sketches offers the most potential to be further developed. Results show that persuasive sketches offer the broadest range of ideas since they are produced as a combination of ideas from brainstorming sessions. Shared sketches help to achieve consensus in decision-making since the sketches are most likely to be produced by the entire group rather than individually. 相似文献
995.
Maadeed Somaya Al Jiang Xudong Rida Imad Bouridane Ahmed 《Multimedia Tools and Applications》2019,78(5):5665-5679
Multimedia Tools and Applications - Among various palmprint identification methods proposed in the literature, Sparse Representation for Classification (SRC) is very attractive, offering high... 相似文献
996.
In this investigation, a novel use of the solar absorption refrigeration systems was introduced by using it to enhance the operation of vacuum wastewater treatment plant. Wastewater treatment systems require a source of heat for evaporation, a cooling section for condensation and a mean of evacuation to facilitate evaporation. The solar absorption system can take over the first two tasks. Among the commercially available vacuum evaporators, one was selected and modified by replacing the conventional heat pump with the solar absorption system. Two validated mathematical models available in the literature, one for solar absorption subsystem and one for vacuum evaporation subsystem, were integrated together to perform the analysis. The impacts of solar absorption subsystem parameters along with vacuum evaporator subsystem parameters on the overall performance were investigated using the developed program. System performance was evaluated in terms of evaporation rate and condensate rate production. It was found that the degree of superheat had the greatest impact on the rate of evaporation. At low levels of supply temperature to the vacuum chamber, using only heat provided by the absorption system, the evaporation rate exceeded 60 kg/h. If the hot water was further heated by passing through the solar collector storage tank, the evaporation rate exceeded 200 kg/h. 相似文献
997.
998.
The principal aim of this study was to compare the sliding wear performance of as-sprayed and Hot Isostatically Pressed (HIPed)
thermal spray cermet (WC-12Co) coatings. Results indicate that HIPing technique can be successfully applied to post-treat
thermal spray cermet coatings for improved sliding wear performance, not only in terms of coating wear, but also in terms
of the total volume loss for test couples. WC-12Co coatings sprayed by a HVOF system were deposited on SUJ-2 bearing steel
substrate and then encapsulated and HIPed at 850 °C for one hour. A high frequency reciprocating ball on plate rig was used
to measure the sliding wear resistance of these coatings in dry conditions under steel and ceramic contact configurations
at two different loads. Results are discussed in terms of coating microstructure, microhardness, fracture toughness and residual
stress evaluations. Microstructural investigations indicate fundamental changes in grain morphology, whereas x-ray diffraction
revealed beneficial transformations in phase composition of these coatings during the HIPing post treatment. The effects of
these microstructural changes on the physical properties and wear resistance are discussed. 相似文献
999.
1000.
Effect of reconfiguration costs on planning for capacity scalability in reconfigurable manufacturing systems 总被引:1,自引:1,他引:1
Ahmed M. Deif Waguih ElMaraghy 《International Journal of Flexible Manufacturing Systems》2006,18(3):225-238
In a globally competitive market for products, manufacturers are faced with an increasing need to improve their flexibility,
reliability, and responsiveness to meet the demands of their customers. Reconfigurable manufacturing systems (RMS) have become
an important manufacturing paradigm, because they broadly encompass the ability to react efficiently to this environment by
providing the exact capacity and functionality needed when needed. This paper studies how such new systems can manage their
capacity scalability planning in a cost effective manner. An approach for modeling capacity scalability planning is proposed.
The development of the model is based on set theory and the regeneration point theorem which is mapped to the reconfigurable
manufacturing paradigm as the capacity scalability points of that system. The cost function of the model incorporates both
the physical capacity cost based on capacity size and costs associated with the reconfiguration process which referred to
as the scalability penalty cost and scalability effort cost. A dynamic programming (DP) approach is manipulated for the development
of optimal capacity scalability plans. The effect of the reconfiguration costs on the capacity scalability planning horizon
and overall cost is investigated. The results showed the relation between deciding on the optimal capacity scalability planning
horizon and the different reconfiguration costs. Results also highlighted the fact that decreasing costs of reconfiguration
will lead to cost effective implementation of reconfigurable manufacturing systems. 相似文献