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This paper investigated four different S-CO2 Brayton cycle layouts for nuclear energy conversion: simple recuperation cycle (SR), recompression cycle (RC), re-heating cycle (RH), and intercooling cycle (IC). We compared these S-CO2 Brayton cycle schemes for nuclear energy conversion using the G1+TOPSIS multi-index evaluation method. The evaluation results of different schemes based on their safety, thermodynamics, techno-economic and compactness are given. The results show that for Generation IV reactors with the same designed thermal power, the thermodynamic performance of the S-CO2 system is better for higher reactor exit temperature. Among the schemes, the gas-cooled fast reactor (GFR)+RC scheme has the highest thermal efficiency (47.4%) and exergy efficiency (56.48%). The GFR+IC scheme has the lowest specific cost (1861.3$/W) and the internal rate of return (24.8%). The re-heating cycle (RH) has worse indexes, but it requires the lowest initial investment cost. The intercooling cycle (IC) has the lowest levelized cost of electricity (0.0134 $/KW•h) coupling to GFR. Considering all indexes of four aspects, the reactor's performance ranking is MSR>LFR>SFR>GFR, and the S-CO2 system's performance ranking is RC>SR>IC>RH. For Generation IV nuclear energy conversion technologies, the molten salt reactor (MSR)+RC scheme should be given priority, while GFR+RH schemes should be carefully considered. [ABSTRACT FROM AUTHOR]

PD-1/PD-L1 inhibitors have been demonstrated to induce itch in both humans and experimental animals. However, whether the PD-1/PD-L1 pathway is involved in the regulation of chronic psoriatic itch remains unclear. This study aimed to investigate the role of the PD-1/PD-L1 pathway in imiquimod-induced chronic psoriatic itch. The intradermal injection of PD-L1 in the nape of neck significantly alleviated chronic psoriatic itch in imiquimod-treated skin. Additionally, we observed that spontaneous scratching behavior induced by imiquimod disappeared on day 21. Still, intradermal injection of PD-1/PD-L1 inhibitors could induce more spontaneous scratching for over a month, indicating that imiquimod-treated skin remained in an itch sensitization state after the spontaneous scratching behavior disappeared. During this period, there was a significant increase in PD-1 receptor expression in both the imiquimod-treated skin and the spinal dorsal horn in mice, accompanied by significant activation of microglia in the spinal dorsal horn. These findings suggest the potential involvement of the peripheral and central PD-1/PD-L1 pathways in regulating chronic itch and itch sensitization induced by imiquimod. [ABSTRACT FROM AUTHOR]

Carbon dots tend to aggregate into clusters during lyophilisation, and the obtained powder is highly hygroscopic and not easy to store. This study introduces a simple way to solve it. Hydroxypropyl methyl cellulose(HPMC)was selected to enhance the stability of carbon dot powder after freeze-dried. Firstly, an interesting carbon dot had been prepared from L-arginine via hydrothermal method, which showed certain antibacterial properties towards E. coli and S.aureus. Secondly, mixing carbon dots aqueous solution with HPMC according to mass ration and stirred evenly. Put the mixture into freeze drying oven until dried, and got the powder, which was tested by XPS and IR. The results demonstrated that the content of surface element in carbon dots powder has changed and owned the characteristics of HPMC. The developed carbon dot powder exhibited similar antibacterial and optical properties to those solutions and emitted significant blue fluorescence when irradiated by an ultraviolet lamp. Importantly, the solid carbon dot powder has high stability under ambient temperatures. It is stable in storage for up to one year and is no longer hygroscopic. However, the common carbon dot aqueous solution without HPMC after freeze-drying is extremely hygroscopic at room temperature and not easy to store. [ABSTRACT FROM AUTHOR]

Focusing mainly on the compressive-shear (C-S) stress, the existing soil strength theories fail to well describe the soil strength under tenso–shear (T-S) stress and are not suitable for analyzing the tensile strength and T-S coupling strength. Taking the T-S strength into account, a three-dimensional nonlinear strength model of soil is established. The failure function on the π plane is a Lade Lade-curved triangle in principal stress space, which reasonably reflects the effect of medium principal stress. The failure function on the triaxial compression meridian plane is divided into the T-S and C-S zones, in which the two failure functions are smoothly connected at the closed stress point. To easily combine it with the specific elastoplastic constitutive theory, the proposed strength model is transformed into the D-P criterion in transformed stress space using the transformation stress method, which provides a theoretical foundation for numerical calculations. Compared with the true triaxial test results and numerical slope examples, the proposed model gives a good description of the nonlinear soil strength under complex stresses and the instability failure mechanism of the slope. [ABSTRACT FROM AUTHOR]

Ultra-high voltage (UHV) transformer has a high seismic vulnerability. The transformers are usually directly connected to the shaking table to conduct an experiment to study its seismic performance, without considering the effect of the foundation soil on the upper equipment. In the present study, the transformer was scaled down based on the dimensional theory. Then, a soil box that can effectively eliminate the boundary effect is designed and a method that can simulate the site category is proposed. Finally, shaking table tests were conducted on rigid foundations and type I site for the scaled-down model, the seismic response of equipment under different site types is obtained. The results imply that under the rigid foundation, the transformer body response is larger with the seismic wave input in the X+Z direction compared to the seismic wave input in the X-direction; as the seismic acceleration increase, the acceleration and strain of bushings gradually ascend, and the response of bushing with Y direction earthquake wave input is significant than that with X direction earthquake wave input. Under type I site condition, with the earthquake excitation increase, the acceleration amplification effect for transformer body caused by the soil–structure interaction decreases gradually; the response of high voltage bushing under earthquake waves is more significant compared with medium and low voltage bushing; with the earthquake excitation increases, the acceleration of high voltage bushing is 1.13 to 1.40 times that of rigid foundation connection, and the strain response is 1.01 to 1.26 times that of rigid foundation connection. The research findings can be applied in the seismic field of UHV transformers to improve the level of seismic design. [ABSTRACT FROM AUTHOR]