35 research outputs found

    Rescheduling of wet season (T. Aman) rice planting for cropping intensification in coastal Bangladesh

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    About 1.0 million ha coastal lands in Bangladesh are mono-cropped suffer from varying degree of soil salinity, waterlogging and climate vulnerability. Low yielding, traditional T. Aman rice is grown only in wet season. Growing non-rice crop after late harvested T. Aman rice is not profitable. This study was aimed to introduce high yielding, short duration T. Aman rice varieties for advancing its harvesting time and to make the avenue for timely establishment of dry season crops. Varietal trials were made at Dacope and Amtali under ACIAR funded project during 2016-2018 and compared with local cultivars. Among tested varieties BRRI dhan76 followed by BRRI dhan77 and BRRI dhan54 in Dacope and BRRI dhan77 followed by BRRI dhan76 and BRRI dhan54 in Amtali were preferred for 0.5–1.0 tha−1 yield advantage and 15–25 days earliness compared to traditional varieties. Early harvesting of T. Aman created the avenue of timely establishment of rice and non-rice crops depending on availability of fresh water and thus crop intensification and land productivity was improved. The new cropping system increased annual rice yield and farmers’ profits by 1.5- to 2-folds compared with traditional system without environmental degradation. This technique can be replicated in similar coastal zones of Bangladesh

    Docosahexaenoic Acid Inhibits UVB-Induced Activation of NF-κB and Expression of COX-2 and NOX-4 in HR-1 Hairless Mouse Skin by Blocking MSK1 Signaling

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    Exposure to ultraviolet-B (UVB) radiation induces inflammation and photocarcinogenesis in mammalian skin. Docosahexaenoic acid (DHA), a representative ω-3 polyunsaturated fatty acid, has been reported to possess anti-inflammatory and chemopreventive properties. In the present study, we investigated the molecular mechanisms underlying the inhibitory effects of DHA on UVB-induced inflammation in mouse skin. Our study revealed that topical application of DHA prior to UVB irradiation attenuated the expression of cyclooxygenase-2 (COX-2) and NAD(P)H:oxidase-4 (NOX-4) in hairless mouse skin. DHA pretreatment also attenuated UVB-induced DNA binding of nuclear factor-kappaB (NF-κB) through the inhibition of phosphorylation of IκB kinase-α/β, phosphorylation and degradation of IκBα and nuclear translocation of p50 and p65. In addition, UVB-induced phosphorylation of p65 at the serine 276 residue was significantly inhibited by topical application of DHA. Irradiation with UVB induced phosphorylation of mitogen and stress-activated kinase-1 (MSK1), extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein (MAP) kinase, and all these events were attenuated by pretreatment with DHA. Blocking ERK and p38 MAP kinase signaling by U0126 and SB203580, respectively, diminished MSK1 phosphorylation in UVB-irradiated mouse skin. Pretreatment with H-89, a pharmacological inhibitor of MSK1, abrogated UVB-induced activation of NF-κB and the expression of COX-2 and NOX-4 in mouse skin. In conclusion, topically applied DHA inhibits the UVB-induced activation of NF-κB and the expression of COX-2 and NOX-4 by blocking the phosphorylation of MSK1, a kinase downstream of ERK and p38 MAP kinase, in hairless mouse skin

    Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

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    Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

    Energy and Exergy Analyses of a Flat Plate Solar Collector Using Various Nanofluids: An Analytical Approach

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    Energy and exergy (EnE) efficiencies are considered the most important parameters to compare the performance of various thermal systems. In this paper, an analysis was carried out for EnE efficiencies of a flat plate solar collector (FPSC) using four different kinds of nanofluids as flowing mediums, namely, Al2O3/water, MgO/water, TiO2/water, and CuO/water, and compared with water as a flowing medium (traditional base fluid). The analysis considered nanofluids made of nanomaterials’ volume fractions of 1–4% with water. The volume flow rates of nanofluids and water were 1 to 4 L/min. The solar collector′s highest EnE efficiency values were obtained for CuO/water nanofluid among the four types of nanofluids mentioned above. The EnE efficiencies of the CuO nanofluid-operated solar collector were 38.21% and 34.06%, respectively, which is significantly higher than that of water-operated solar collectors. For the same volume flow rate, the mass flow rate was found to be 15.95% higher than water for the CuO nanofluid. The EnE efficiency of FPSC can also be increased by increasing the density and reducing the specific heat of the flowing medium

    Experimental investigation on thermo physical properties of single walled carbon nanotube nanofluids

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    This experimental study is aimed to measure and analyze the thermal conductivity, viscosity, and specific heat of water based single walled carbon nanotube (SWCNT) nanofluids in presence of sodium dodecyl sulfate (SDS) surfactant. The surfactant was used to prepare stable nanofluids and the stability of SWCNT nanofluids of five volume concentrations (0.05-0.25 vol%) is observed good. The measured values of thermal conductivity in the range of 0.615-0.892 W/m K, viscosity in the range of 0.67-1.28 mPa s, and the specific heat in the range of 2.97-3.90 kJ/kg degrees C, were observed for temperature rising from 20 to 60 degrees C with an interval of 10 degrees C as the volume concentration increased from 0.05 to 0.25 vol%. The maximum thermal conductivity enhancement of 36.39% compared to water is observed for 0.25 vol% at 60 degrees C. The viscosity of SWCNT nanofluids exhibited a non-Newtonian shear-thinning behavior due to the alignment of nanotube clusters and agglomerates with increasing shear rate. The temperature and volume concentrations have effect on specific heat as well and it decreases with particle loadings while increases with temperature

    Thermodynamic Analysis of a Flat Plate Solar Collector with Different Hybrid Nanofluids as Working Medium—A Thermal Modelling Approach

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    In this study, the performance of hybrid nanofluids in a flat plate solar collector was analysed based on various parameters such as entropy generation, exergy efficiency, heat transfer enhancement, pumping power, and pressure drop. Five different base fluids were used, including water, ethylene glycol, methanol, radiator coolant, and engine oil, to make five types of hybrids nanofluids containing suspended CuO and MWCNT nanoparticles. The nanofluids were evaluated at nanoparticle volume fractions ranging from 1% to 3% and flow rates of 1 to 3.5 L/min. The analytical results revealed that the CuO-MWCNT/water nanofluid performed the best in reducing entropy generation at both volume fractions and volume flow rate when compared to the other nanofluids studied. Although CuO-MWCNT/methanol showed better heat transfer coefficients than CuO-MWCNT/water, it generated more entropy and had lower exergy efficiency. The CuO-MWCNT/water nanofluid not only had higher exergy efficiency and thermal performance but also showed promising results in reducing entropy generation

    Nano-Pd/Chitosan Composite: An Extremely Effective Catalyst to the Synthesis of Pyrazolyl Analogues through Suzuki–Miyaura Cross-Coupling Reactions in an Aqueous Medium

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    Substituted pyrazolyl derivatives were synthesized through Suzuki cross coupling of aromatic boronic acid with heterocyclic halide using newly synthesized nano-Pd/chitosan catalyst by the water-mediated green synthesis methodology. The reactivity of the nano-Pd catalyst was highly enhanced by incorporating palladium nanoparticles with a biopolymer chitosan matrix. The synthesized nano-Pd/chitosan catalyst was studied thoroughly for its structure, morphology, and other fundamental aspects such as the size and shape by various techniques including XRD, FESEM, and EDAX analyses. The scope of the catalyst was disclosed by their great stability with remarkable reusability for Suzuki cross-coupling reaction with twelve different boronic acids under the green synthetic methodology
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