The Caenorhabditis elegans DAF-16 transcription factor is critical for diverse biological processes, particularly longevity and stress resistance. Disruption of the DAF-2 signaling cascade promotes DAF-16 activation, and confers resistance to killing by pathogenic bacteria, such as Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis. However, daf-16 mutants exhibit similar sensitivity to these bacteria as wild-type animals, suggesting that DAF-16 is not normally activated by these bacterial pathogens. In this report, we demonstrate that DAF-16 can be directly activated by fungal infection and wounding in wild-type animals, which is independent of the DAF-2 pathway. Fungal infection and wounding initiate the Gαq signaling cascade, leading to Ca2+ release. Ca2+ mediates the activation of BLI-3, a dual-oxidase, resulting in the production of reactive oxygen species (ROS). ROS then activate DAF-16 through a Ste20-like kinase-1/CST-1. Our results indicate that DAF-16 in the epidermis is required for survival after fungal infection and wounding. Thus, the EGL-30-Ca2+-BLI-3-CST-1-DAF-16 signaling represents a previously unknown pathway to regulate epidermal damage response.
A novel phase change emulsion (PCE) was prepared and its latent heat was measured by DSC. To analyze its feasibility in heat transportation through a piping system, an experimental system was built. The pressure drop of the PCE for turbulent flow was measured and the effects of such facts as the paraffin concentration and flow velocity were discussed. According to the pressure characteristic and latent heat of the PCE, the pumping power consumption rates of PCE to water under the same pipe diameter and a given heat transportation quantity can be obtained. The results show that mass flow rate and pumping power consumption of the PCE decrease greatly compared with water. For example, the decrease can be up to about 73% at V¼ 0.6 m/s (20 and 30 wt%). Furthermore, the results show that PCE of 20 wt% can obtain almost the same pumping power consumption savings as PCE of 30 wt% in a certain flow velocity range. Finally, the applications of the PCE in the area of waste heat usage, electrical boiler and solar energy usage were commented.
Summary
For a heat pump, three injection styles including liquid, two‐phase, and vapor injection are used to improve its performance. But there is no quantitative index to define the injection styles. They are distinguished from the injection configurations. The subcooler refrigerant injection (SCRI) is generally considered as the vapor injection. In this study, the injection super‐heating degree (ΔTinj) is introduced as a technical parameter to define the injection style. The ΔTinj is affected by the subcooling degree (ΔTsc). These two parameters are used to study their effects on the heat pump performance. Experimental and theoretical analysis reveals that three injection styles can be selectively achieved in the SCRI configuration by the suitable control of the main and subcooling electronic expansion valves. Additionally, for liquid and two‐phase injection, it can improve heating capacity (Qh) by heightening the ΔTsc to increase the heat exchange amount in the evaporator. For vapor injection, in addition to increase of the ΔTsc, the Qh can be enhanced by raising the ΔTinj to lift the compression power of the compressor. The two‐phase injection is more beneficial to enhance the heat pump performance than the liquid injection and two‐phase injection. The largest Qh and corresponding increase amplitude (δQh) were, respectively, obtained with two‐phase injection to be 13 577 W and 13.5%, and the corresponding COP and increase amplitude (δCOP) were, respectively, 2.36 and 16.8%.
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