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131.
Motivated by the theory of self‐duality that provides a variational formulation and resolution for non‐self‐adjoint partial differential equations (Ann. Inst. Henri Poincaré (C) Anal Non Linéaire 2007; 24 :171–205; Selfdual Partial Differential Systems and Their Variational Principles. Springer: New York, 2008), we propose new templates for solving large non‐symmetric linear systems. The method consists of combining a new scheme that simultaneously preconditions and symmetrizes the problem, with various well‐known iterative methods for solving linear and symmetric problems. The approach seems to be efficient when dealing with certain ill‐conditioned, and highly non‐symmetric systems. The numerical and theoretical results are provided to show the efficiency of our approach. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
132.
Pejić Bach Mirjana Topalović Amir Turulja Lejla 《Central European Journal of Operations Research》2023,31(3):941-973
Central European Journal of Operations Research - Data mining is the process of knowledge extraction from the data with the algorithms that identify hidden relationships and patterns, which are... 相似文献
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Zahra Bashiri Ali Moghaddaszadeh Reza Falak Farnaz Khadivi Azita Afzali Mehdi Abbasi Ali Mohammad Sharifi Hamid Reza Asgari Farid Ghanbari Morteza Koruji 《Macromolecular bioscience》2023,23(9):2200574
In vitro production of sperm is a desirable idea for fertility preservation in azoospermic men and prepubertal boys suffering from cancer. In this study, a biocompatible porous scaffold based on a triad mixture of silk fibroin (SF), alginate (Alg), and laminin (LM) is developed to facilitate the differentiation of mouse spermatogonia stem cells (SSCs). Following SF extraction, the content is analyzed by SDS-PAGE and stable porous 3D scaffolds are successfully prepared by merely Alg, SF, and a combination of Alg-SF, or Alg-SF-LM through freeze-drying. Then, the biomimetic scaffolds are characterized regarding the structural and biological properties, water absorption capacity, biocompatibility, biodegradability, and mechanical behavior. Neonatal mice testicular cells are seeded on three-dimensional scaffolds and their differentiation efficiency is evaluated using real-time PCR, flow cytometry, immunohistochemistry. Blend matrices showed uniform porous microstructures with interconnected networks, which maintained long-term stability and mechanical properties better than homogenous structures. Molecular analysis of the cells after 21 days of culture showed that the expression of differentiation-related proteins in cells that are developed in composite scaffolds is significantly higher than in other groups. The application of a composite system can lead to the differentiation of SSCs, paving the way for a novel infertility treatment landscape in the future. 相似文献
136.
Ahmad VU Arshad S Bader S Iqbal S Khan A Khan SS Hussain J Tareen RB Ahmed A 《Magnetic resonance in chemistry : MRC》2008,46(10):986-989
Two new triterpenoidal saponins were isolated from the n-butanolic extract of Stachys parviflora (Lamiaceae). Their structures were elucidated on the basis of spectral data as stachyssaponin A; 3beta, 15alpha, 19alpha, 21beta, 22alpha-pentahydroxyolean-12-ene-28-oic acid 3-O-{alpha-L-rhamnopyranosyl-(1 --> 3)-beta-D-glucopyranoside}-22-O-{alpha-L-arabinofuranosyl-(1 --> 3)-beta-D-glucopyranoside} (1) and stachyssaponin B; 2beta, 3beta, 15alpha, 21beta-tetrahydroxyolean-12-ene-28-oic acid 2-O-[alpha-L-arabinofuranoside]-3, 21-bis-O-[beta-D-glucopyranoside] (2). 相似文献
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Silica gel supported aluminum chloride (SiO2‐AlCl3) and cross‐linked polystyrene‐supported aluminum chloride (PS‐AlCl3) are environment‐ friendly heterogeneous catalysts for the condensation of amines and aldehydes with diethyl phosphite to afford α‐aminophosphonates. These solid acid catalysts are stable (as bench top catalysts) and can be easily recovered and reused without appreciable change in their efficiency. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:418–422, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20629 相似文献
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Structural Chemistry - Carbon force fields are widely used for obtaining structural properties of carbon nanomaterials. We evaluate the performance of a wide range of carbon force fields for... 相似文献
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Rostamian Seyed Hadi Saedodin Seyfolah Asgari Seyed Abbas Salarian Amir Hasan 《Journal of Thermal Analysis and Calorimetry》2022,147(1):155-167
Journal of Thermal Analysis and Calorimetry - In this study, the thermophysical and tribological properties of a hybrid nanofluid containing fullerene-silica nanoparticles in a multigrade engine... 相似文献