716 research outputs found
Analysis of operation performance of three indirect expansion solar assisted air source heat pumps for domestic heating
To achieve the goal set for net-zero emissions of greenhouse gases in the UK by 2050, the domestic heating must be decarbonised. Solar assisted air source heat pumps, integrating solar collector, thermal energy storage tank and heat pump, offers a promising alternative application under the UK weather conditions. Literature review shows that investigations of solar assisted air source heat pumps in the regions like the UK are still insufficient. The serial, parallel and dual-source indirect expansion solar assisted air source heat pumps are modelled and simulated under the weather conditions in London using TRNSYS to investigate the operation performance over a typical year. These three heat pumps are applied to provide space heating and hot water of 300 L per day for a typical single-family house. The simulation results show comparisons of the three systems. The serial type heat pump shows the highest seasonal performance factor of 5.5, but requiring the largest sizes of the solar collector and thermal energy storage tank. The dual-source and parallel type heat pumps show slightly lower seasonal performance factors of 4.4 and 4.5, respectively, requiring smaller sizes of solar collector and thermal energy storage tank. Furthermore, the results show that the air source part contributes to an important proportion of the heat provision and stable operation of the systems. The yearly seasonal performance factor higher than 4.4 achievable by the three heat pumps suggests that they are potentially applied in the regions with relatively lower solar irradiance. The economic analyses indicate that the parallel and dual-source type heat pumps provide good alternatives to replace the gas-boiler heating system
Effectiveness of Acupuncture for Early Recovery of Bowel Function in Cancer: A Systematic Review and Meta-Analysis
Objectives. The aim of this study was to evaluate the effects of acupuncture therapy to reduce the duration of postoperative ileus (POI) and to enhance bowel function in cancer patients. Methods. A systematic search of electronic databases for studies published from inception until January 2017 was carried out from six databases. Randomized controlled trials (RCTs) involving the use of acupuncture and acupressure for POI and bowel function in cancer patients were identified. Outcomes were extracted from each study and pooled to determine the risk ratio and standardized mean difference. Results. 10 RCTs involving 776 cancer patients were included. Compared with control groups (no acupuncture, sham acupuncture, and other active therapies), acupuncture was associated with shorter time to first flatus and time to first defecation. A subgroup analysis revealed that manual acupuncture was more effective on the time to first flatus and the time to first defecation; electroacupuncture was better in reducing the length of hospital stay. Compared with control groups (sham or no acupressure), acupressure was associated with shorter time to first flatus. However, GRADE approach indicated a low quality of evidence. Conclusions. Acupuncture and acupressure showed large effect size with significantly poor or inferior quality of included trials for enhancing bowel function in cancer patients after surgery. Further well-powered evidence is needed
Phase transformation-induced improvement in hardness and high-temperature wear resistance of plasma-sprayed and remelted NiCrBSi/WC coatings
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. The remelting method is introduced to improve the properties of the as-sprayed NiCrBSi coatings. In this work, tungsten carbide (WC) was selected as reinforcement and the as-sprayed and remelted NiCrBSi/WC composite coatings were investigated by X-ray diffraction, scanning electron microscopy, hardness test and tribology test. After spraying, WC particles are evenly distributed in the coating. The remelting process induced the decarburizing reaction of WC, resulting in the formation of dispersed W2 C. The dispersed W2 C particles play an important role in the dispersion strengthening. Meanwhile, the pores and lamellar structures are eliminated in the remelted NiCrBSi/WC composite coating. Due to these two advantages, the hardness and the high-temperature wear resistance of the remelted NiCrBSi/WC composite coating are significantly improved compared with those with an as-sprayed NiCrBSi coating; the as-sprayed NiCrBSi coating, as-sprayed NiCrBSi/WC composite coating and remelted NiCrBSi/WC composite coating have average hardness of 673.82 HV, 785.14 HV, 1061.23 HV, and their friction coefficients are 0.3418, 0.3261, 0.2431, respectively. The wear volume of the remelted NiCrBSi/WC composite coating is only one-third of that of the as-sprayed NiCrBSi coating
ER-α36, a Novel Variant of ER-α, Mediates Estrogen-Stimulated Proliferation of Endometrial Carcinoma Cells via the PKCδ/ERK Pathway
Recently, a variant of ER-α, ER-α36 was identified and cloned. ER-α36 lacks intrinsic transcription activity and mainly mediates non-genomic estrogen signaling. The purpose of this study was to investigate the function and the underlying mechanisms of ER-α36 in growth regulation of endometrial Ishikawa cancer cells.The cellular localization of ER-α36 and ER-α66 were determined by immunofluorescence in the Ishikawa cells. Ishikawa endometrial cancer control cells transfected with an empty expression vector, Ishikawa cells with shRNA knockdown of ER-α36 (Ishikawa/RNAiER36) and Ishikawa cells with shRNA knockdown of ER-α66 (Ishikawa/RNAiER66) were treated with E2 and E2-conjugated to bovine serum albumin (E2-BSA, membrane impermeable) in the absence and presence of different kinase inhibitors HBDDE, bisindolylmaleimide, rottlerin, H89 and U0126. The phosphorylation levels of signaling molecules and cyclin D1/cdk4 expression were examined with Western blot analysis and cell growth was monitored with the MTT assay.Immunofluorescence staining of Ishikawa cells demonstrated that ER-α36 was expressed mainly on the plasma membrane and in the cytoplasm, while ER-α66 was predominantly localized in the cell nucleus. Both E2 and E2-BSA rapidly activated PKCδ not PKCα in Ishikawa cells, which could be abrogated by ER-α36 shRNA expression. E2-and E2-BSA-induced ERK phosphorylation required ER-α36 and PKCδ. However, only E2 was able to induce Camp-dependent protein kinase A (PKA) phosphorylation. Furthermore, E2 enhances cyclin D1/cdk4 expression via ER-α36.E2 activates the PKCδ/ERK pathway and enhances cyclin D1/cdk4 expression via the membrane-initiated signaling pathways mediated by ER-α36, suggesting a possible involvement of ER-α36 in E2-dependent growth-promoting effects in endometrial cancer cells
Proteomic identification of OsCYP2, a rice cyclophilin that confers salt tolerance in rice (Oryza sativa L.) seedlings when overexpressed
<p>Abstract</p> <p>Background</p> <p>High Salinity is a major environmental stress influencing growth and development of rice. Comparative proteomic analysis of hybrid rice shoot proteins from Shanyou 10 seedlings, a salt-tolerant hybrid variety, and Liangyoupeijiu seedlings, a salt-sensitive hybrid variety, was performed to identify new components involved in salt-stress signaling.</p> <p>Results</p> <p>Phenotypic analysis of one protein that was upregulated during salt-induced stress, cyclophilin 2 (OsCYP2), indicated that <it>OsCYP2 </it>transgenic rice seedlings had better tolerance to salt stress than did wild-type seedlings. Interestingly, wild-type seedlings exhibited a marked reduction in maximal photochemical efficiency under salt stress, whereas no such change was observed for <it>OsCYP2</it>-transgenic seedlings. <it>OsCYP2</it>-transgenic seedlings had lower levels of lipid peroxidation products and higher activities of antioxidant enzymes than wild-type seedlings. Spatiotemporal expression analysis of <it>OsCYP2 </it>showed that it could be induced by salt stress in both Shanyou 10 and Liangyoupeijiu seedlings, but Shanyou 10 seedlings showed higher <it>OsCYP2 </it>expression levels. Moreover, circadian rhythm expression of <it>OsCYP2 </it>in Shanyou 10 seedlings occurred earlier than in Liangyoupeijiu seedlings. Treatment with PEG, heat, or ABA induced <it>OsCYP2 </it>expression in Shanyou 10 seedlings but inhibited its expression in Liangyoupeijiu seedlings. Cold stress inhibited <it>OsCYP2 </it>expression in Shanyou 10 and Liangyoupeijiu seedlings. In addition, OsCYP2 was strongly expressed in shoots but rarely in roots in two rice hybrid varieties.</p> <p>Conclusions</p> <p>Together, these data suggest that OsCYP2 may act as a key regulator that controls ROS level by modulating activities of antioxidant enzymes at translation level. OsCYP2 expression is not only induced by salt stress, but also regulated by circadian rhythm. Moreover, OsCYP2 is also likely to act as a key component that is involved in signal pathways of other types of stresses-PEG, heat, cold, or ABA.</p
Comparative transcriptomics analysis reveals difference of key gene expression between banana and plantain in response to cold stress
Insights into the Ecological Roles and Evolution of Methyl-Coenzyme M Reductase-Containing Hot Spring Archaea
Several recent studies have shown the presence of genes for the key enzyme associated with archaeal methane/alkane metabolism, methyl-coenzyme M reductase (Mcr), in metagenome-assembled genomes (MAGs) divergent to existing archaeal lineages. Here, we study the mcr-containing archaeal MAGs from several hot springs, which reveal further expansion in the diversity of archaeal organisms performing methane/alkane metabolism. Significantly, an MAG basal to organisms from the phylum Thaumarchaeota that contains mcr genes, but not those for ammonia oxidation or aerobic metabolism, is identified. Together, our phylogenetic analyses and ancestral state reconstructions suggest a mostly vertical evolution of mcrABG genes among methanogens and methanotrophs, along with frequent horizontal gene transfer of mcr genes between alkanotrophs. Analysis of all mcr-containing archaeal MAGs/genomes suggests a hydrothermal origin for these microorganisms based on optimal growth temperature predictions. These results also suggest methane/alkane oxidation or methanogenesis at high temperature likely existed in a common archaeal ancestor
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