6,193 research outputs found

    Investigation of Compact Low Pass Filter with Sharp Cut–Off using Metamaterial

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    In this paper a new compact microstrip Bessel low pass filter (LPF) is experimentally validated using complementary split ring resonator (CSRR) which has sharper cut-off and improved spurious band suppression characteristics. The Richard’s transformation and Kuroda’s identities are used for realizing distributed Bessel LPF from the lumped element Bessel LPF. Traditionally Butterworth and Chebyshev LPFs are used in communication systems. Those LPFs exhibits high reflection in the pass-band and it is also very difficult to achieve sharper cut-off. Because of its poor cut-off and non linear phase characteristics, it will create cross talk between microwave systems. In order to overcome the above issues our proposed LPF which has linear phase and sharper cut-off behavior is on ideal subsystem in future microwave systems. Furthermore, to prove its practical viability of the proposed design, a compact microstrip Bessel LPF was designed, simulated, fabricated and measured. It was observed from the experimentally compared results of the proposed Bessel LPF with CSRR has better sharper cut-off characteristic than the without CSRR structure

    Peptide-enhanced mRNA transfection in cultured mouse cardiac fibroblasts and direct reprogramming towards cardiomyocyte-like cells.

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    The treatment of myocardial infarction is a major challenge in medicine due to the inability of heart tissue to regenerate. Direct reprogramming of endogenous cardiac fibroblasts into functional cardiomyocytes via the delivery of transcription factor mRNAs has the potential to regenerate cardiac tissue and to treat heart failure. Even though mRNA delivery to cardiac fibroblasts has the therapeutic potential, mRNA transfection in cardiac fibroblasts has been challenging. Herein, we develop an efficient mRNA transfection in cultured mouse cardiac fibroblasts via a polyarginine-fused heart-targeting peptide and lipofectamine complex, termed C-Lipo and demonstrate the partial direct reprogramming of cardiac fibroblasts towards cardiomyocyte cells. C-Lipo enabled the mRNA-induced direct cardiac reprogramming due to its efficient transfection with low toxicity, which allowed for multiple transfections of Gata4, Mef2c, and Tbx5 (GMT) mRNAs for a period of 2 weeks. The induced cardiomyocyte-like cells had α-MHC promoter-driven GFP expression and striated cardiac muscle structure from α-actinin immunohistochemistry. GMT mRNA transfection of cultured mouse cardiac fibroblasts via C-Lipo significantly increased expression of the cardiomyocyte marker genes, Actc1, Actn2, Gja1, Hand2, and Tnnt2, after 2 weeks of transfection. Moreover, this study provides the first direct evidence that the stoichiometry of the GMT reprogramming factors influence the expression of cardiomyocyte marker genes. Our results demonstrate that mRNA delivery is a potential approach for cardiomyocyte generation

    Carbon Footprint: A New Farm Management Consideration in the Southern High Plains

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    As concerns continue to mount regarding man induced impacts to the global climate, the SHPT region could be faced with a unique scenario in which the net carbon balance should be considered in the producer’s enterprise selection and production systems. Currently, the SHPT produces nearly one third of the U.S. cotton crop. Under a potential cap and trade system the challenge for the agricultural industry in the SHPT may be how to sustain the region’s economic base and production capabilities. Thus, the objective of this study was to measure the net carbon relationships between irrigated cotton and irrigated corn production systems on the SHPT using data from the Texas Alliance for Water Conservation (TAWC, 2009). Due to the unique management and production challenges in the SHPT, additional comparisons were made regarding economic viability and irrigation efficiency. Within the parameters of this study, it is apparent that irrigated corn has an advantage over cotton in both its ability to return carbon to the soil, maintain profitability, and use water resources efficiently. If the agricultural industry is included in CO2 regulation, it would appear that irrigated agricultural producers in the SHPT who have the ability to move between irrigated cotton and corn should be aware of the advantages corn possesses. However, even under changing commodity prices and profitability scenarios, corn still presents a significant advantage over cotton in its ability to reduce atmospheric CO2 by depositing larger amounts of biomass carbon into the soil.Cape and Trade, carbon, farm management, Environmental Economics and Policy, Farm Management, Q18, Q28, Q54, Q56,
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