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991.
In this paper, we will show some connections between fixed point and coupled fixed point problems in Banach and metric spaces. 相似文献
992.
993.
Ayşegül Doğan Mehmet Emir Yalvaç Aysu Yılmaz Albert Rizvanov Fikrettin Şahin 《Applied biochemistry and biotechnology》2013,171(7):1819-1831
The use of stem-cell-based therapies in regenerative medicine and in the treatment of disorders such as Parkinson, Alzheimer's disease, diabetes, spinal cord injuries, and cancer has been shown to be promising. Among all stem cells, mesenchymal stem cells (MSCs) were reported to have anti-apoptotic, immunomodulatory, and angiogenic effects which are attributed to the restorative capacity of these cells. Human tooth germ stem cells (HTGSCs) having mesenchymal stem cell characteristics have been proven to exert high proliferation and differentiation capacity. Unlike bone-marrow-derived MSCs, HTGSCs can be easily isolated, expanded, and cryopreserved, which makes them an alternative stem cell source. Regardless of their sources, the stem cells are exposed to physical and chemical stresses during cryopreservation, hindering their therapeutic capacity. Amelioration of the side effects of cryopreservation on MSCs seems to be a priority in order to maximize the therapeutic efficacy of these cells. In this study, we tested the effect of Pluronic 188 (F68) on HTGSCs during long-term cryopreservation and repeated freezing and defrosting cycles. Our data revealed that F68 has a protective role on survival and differentiation of HTGSCs in long-term cryopreservation. 相似文献
994.
The molecular weight distributions of artificially aged transformer papers were studied using SEC–MALLS with 0.5 % DMAc/LiCl as solvent, providing chain length distributions and averages. The slow dissolution and presence of non-cellulosic contaminants tend in some cases to introduce errors in the DPw estimates, and a modified data processing procedure was developed to correct for extraneous scattering. Data were compared to the intrinsic viscosities obtained in 0.5 M Cuen and the ‘viscosimetric DP’ calculated thereof according to ISO 5351. DPvisc was 2–3 times lower than the weight average DP (DPw), but closer to or slightly above the number average DP (DPn) obtained by SEC–MALLS in the case of pure cellulose. Ageing of transformer papers were in some cases associated with changes in the polydispersity (DPw/DPn). The apparent degradation rate (defined as δ(1/DP)/δt) gradually decreased with time, resulting in a tendency for a ‘level-off’ DP in the range 200–300 for DPvisc and DPn, and roughly 1,000 for DPw. 相似文献
995.
996.
In this paper we study the two-body problem that describes the motion of two-point masses in an anisotropic space under the influence of the Seeliger potential. We will show that the set of initial conditions leading to collisions and ejections has positive measure and study the capture and escape solutions in the positive-energy case using the infinity manifold. We will also apply the Melnikov method to show that the flow on the zero-energy manifold of another potential which is the sum of the classical Keplerian potential and the anisotropic Seeliger's potential perturbation is chaotic. 相似文献
997.
998.
Tayfun Hüyük Antonio Di Nitto Grzegorz Jaworski Andrés Gadea José Javier Valiente-Dobón Johan Nyberg Marcin Palacz Pär-Anders Söderström Ramon Jose Aliaga-Varea Giacomo de Angelis Ayşe Ataç Javier Collado Cesar Domingo-Pardo Francisco Javier Egea Nizamettin Erduran Sefa Ertürk Gilles de France Rafael Gadea Vicente González Vicente Herrero-Bosch Ayşe Kaşkaş Victor Modamio Marek Moszynski Enrique Sanchis Andrea Triossi Robert Wadsworth 《The European Physical Journal A - Hadrons and Nuclei》2016,52(3):55
999.
1000.
The advances in the technological infrastructure and in the Internet led electronic auctions to become popular. With online sites, people buy/sell inexpensive products/services through auctions. In this paper, we develop an interactive approach that provides aid to both the buyer and the bidders in a bi-attribute, multi-item auction environment. Our approach is applicable for both reverse and forward auctions. We test our approach for underlying linear preference functions of the buyer. We also adapt it as a heuristic for the case the buyer has a nonlinear preference function. The test results show that our approach works well. 相似文献