Oxidative stress and inflammation play major roles in the pathogenesis of coronary heart disease including myocardial infarction (MI). The pathological progression following MI is very complex and involves a number of cell populations including cells localized within the heart, as well as cells recruited from the circulation and other tissues that participate in inflammatory and reparative processes. These cells, with their secretory factors, have pleiotropic effects that depend on the stage of inflammation and regeneration. Excessive inflammation leads to enlargement of the infarction site, pathological remodeling and eventually, heart dysfunction. Stem cell therapy represents a unique and innovative approach to ameliorate oxidative stress and inflammation caused by ischemic heart disease. Consequently, it is crucial to understand the crosstalk between stem cells and other cells involved in post-MI cardiac tissue repair, especially immune cells, in order to harness the beneficial effects of the immune response following MI and further improve stem cell-mediated cardiac regeneration. This paper reviews the recent findings on the role of antioxidation and immunomodulation in postnatal multipotent stem cell-mediated cardiac repair following ischemic heart disease, particularly acute MI and focuses specifically on mesenchymal, muscle and blood-vessel-derived stem cells due to their antioxidant and immunomodulatory properties. 相似文献
Optimal crop water allocation has become more challenging in drier areas of the world (short of rainfall) due to increased water scarcity and more frequent droughts. alternative cropping patterns, reallocation of water resources and modification of irrigation are some of the strategies used to address droughts . A new optimization model is used in this study to find the optimal cropping patterns during droughts, while benefiting from deficit irrigation to decrease the total allocated water. Moreover, the proposed model is subjected to a proportional cutback constraint to meet optimized proportional water allocation under limited water condition. As a real case study, two related districts, namely Neku-abad and Abshar located in Zayandeh-rud River basin are considered. Zayandeh-rud river basin is located in the central part of Iran. For better illustration of model outputs, the proposed model was checked using various irrigation efficiency values (60–100 % in 10 % interval), water reduction ratios (0.0–0.4) and cutback parameters (λa?=?0.3,?λn?=?0.7, λa?=?0.51,?λn?=?0.49 and λa?=?λn?=?0.5). The results showed that the values of λa?=?0.51,?λn?=?0.49 presents the maximum proportionality in terms of water reduction among all the allocation units or users. Although different values of cutback parameters (e.g.: λa?=?0.3,?λn?=?0.7) maximize net benefits, they are not considered as proportionate decisions in the considered study area. 相似文献
Silicon - The morphological stability of silicon single crystal wafers was investigated, after performing cleaning surface treatments based on moderate temperature annealing and plasma sputtering.... 相似文献
By the inevitable scaling down of the feature size of the MOS transistors which are deeper in nanoranges, the CMOS technology has encountered many critical challenges and problems such as very high leakage currents, reduced gate control, high power density, increased circuit noise sensitivity and very high lithography costs. Quantum-dot cellular automata (QCA) owing to its high device density, extremely low power consumption and very high switching speed could be a feasible competitive alternative. In this paper, a novel 5-input majority gate, an important fundamental building block in QCA circuits, is designed in a symmetric form. In addition to the majority gate, a SR latch, a SR gate and an efficient one bit QCA full adder are implemented employing the new 5-input majority gate. In order to verify the functionality of the proposed designs, QCADesigner tool is used. The results demonstrate that the proposed SR latch and full adder perform equally well or in many cases better than previous circuits. 相似文献
Economizer use in data centers is an energy efficiency strategy that could significantly limit electricity demand in this rapidly growing economic sector. Widespread economizer implementation, however, has been hindered by potential reliability concerns associated with exposing information technology equipment to particulate matter of outdoor origin. This study explores the feasibility of using economizers in data centers to save energy while controlling particle concentrations with high-quality air filtration. Physical and chemical properties of indoor and outdoor particles were analyzed at an operating northern California data center equipped with an economizer under varying levels of air filtration efficiency. Results show that when improved filtration is used in combination with an economizer, the indoor/outdoor concentration ratios for most measured particle types were similar to levels when using conventional filtration without economizers. An energy analysis of the data center reveals that, even during the summer months, chiller savings from economizer use greatly outweigh any increase in fan power associated with improved filtration. These findings indicate that economizer use combined with improved filtration could reduce data center energy demand while providing a level of protection from particles of outdoor origin similar to that observed with conventional design. 相似文献
A highly efficient stereoselective method for the synthesis of functionalized spirooxindole derivatives with four contiguous stereogenic centers, including two adjacent quaternary stereogenic centers, was realized through an organocatalytic tandem Michael–Michael reaction. By employing a quinidine‐derived thiourea organocatalyst, the reaction between (E)‐2‐cyano‐2‐(2‐oxo‐1‐tritylindolin‐3‐ylidene)acetates and (E)‐1‐alkyl‐6‐nitro‐hex‐2‐en‐1‐ones yields the desired spirooxindole products in good yields (up to 90%) and with excellent stereoselectivities (up to 95:5 dr and 98% ee).