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The two-phase compression process in the rotary compressor often occurs, such as defrosting and startup processes, which has a significant impact on the performance and reliability of air conditioning systems. In this paper, the CFD simulations predicting the two-phase refrigerant compression process in the compressor cylinder are conducted using the commercial software ANSYS Fluent. The dynamic mesh for the fluid domain and phase change model for the refrigerant are considered in the simulation. Effects of initial liquid volume fraction, refrigerant type and compressor type on the two-phase compression characteristics using R290 as refrigerant are carried out. Variations of the pressure, temperature, gas fraction distribution and evaporation rate in the cylinder are discussed. The results show that most liquid accumulates near the leakage gap and the bottom of the compression chamber during the two-phase compression process. The peak pressure during the two-phase compression decreases with the increase of the liquid volume fraction. The evaporation rate of R32 in the cylinder is much higher than that of R290. The maximum pressure of the reciprocating compressor is 2.26 times higher than that of the rotary compressor.

Pathogenesis-related 1 (PR-1) proteins, which are defense proteins in plant–pathogen interactions, play an important role in the resistance and defense of plants against diseases. Blister blight disease is caused by Exobasidium vexans Massee and a major leaf disease of tea plants (Camellia sinensis (L.) O. Kuntze). However, the systematic characterization and analysis of the PR-1 gene family in tea plants is still lacking, and the defense mechanism of this family remains unknown. In this study, 17 CsPR-1 genes were identified from the tea plant genome and classified into five groups based on their signal peptide, isoelectric point, and C-terminus extension. Most of the CsPR-1 proteins contained an N-terminal signal peptide and a conserved PR-1 like domain. CsPR-1 genes comprised multiple cis-acting elements and were closely related to the signal-transduction pathways involving TCA, NPR1, EDS16, BGL2, PR4, and HCHIB. These characteristics imply an important role of the genes in the defense of the tea plant. In addition, the RNA-seq data and real-time PCR analysis demonstrated that the CsPR-1-2, -4, -6, -7, -8, -9, -10, -14, -15, and -17 genes were significantly upregulated under tea blister-blight stress. This study could help to increase understanding of CsPR-1 genes and their defense mechanism in response to tea blister blight.

Signalling epidermal growth The maintenance and regeneration of the adult bladder epithelium is poorly understood, yet it is clinically relevant to the development of urinary-tract infections and bladder cancer. A new study provides insight into the cellular and molecular mechanisms underlying the regenerative response to injury within the mammalian urinary bladder. On injury by bacterial infection or chemical agents, a Shh and Wnt signalling feedback circuit between basal cells of the urothelium and the stromal cells that underlie them leads to regenerative proliferation of the bladder epithelia. The maintenance and regeneration of the epithelium of the adult bladder is poorly understood yet it is a clinically relevant process during urinary tract infections and bladder cancer. This study provides insight into the cellular and molecular mechanisms underlying the regenerative response to injury within the mammalian urinary bladder. Upon injury by bacterial infection or chemical agents, a Shh and Wnt signalling feedback circuit between basal cells of the urothelium and the stromal cells that underlie them leads to regenerative proliferation of the bladder epithelia. Epithelial integrity in metazoan organs is maintained through the regulated proliferation and differentiation of organ-specific stem and progenitor cells. Although the epithelia of organs such as the intestine regenerate constantly and thus remain continuously proliferative 1 , other organs, such as the mammalian urinary bladder, shift from near-quiescence to a highly proliferative state in response to epithelial injury 2 , 3 , 4 . The cellular and molecular mechanisms underlying this injury-induced mode of regenerative response are poorly defined. Here we show in mice that the proliferative response to bacterial infection or chemical injury within the bladder is regulated by signal feedback between basal cells of the urothelium and the stromal cells that underlie them. We demonstrate that these basal cells include stem cells capable of regenerating all cell types within the urothelium, and are marked by expression of the secreted protein signal Sonic hedgehog (Shh). On injury, Shh expression in these basal cells increases and elicits increased stromal expression of Wnt protein signals, which in turn stimulate the proliferation of both urothelial and stromal cells. The heightened activity of this signal feedback circuit and the associated increase in cell proliferation appear to be required for restoration of urothelial function and, in the case of bacterial injury, may help clear and prevent further spread of infection. Our findings provide a conceptual framework for injury-induced epithelial regeneration in endodermal organs, and may provide a basis for understanding the roles of signalling pathways in cancer growth and metastasis.

In this study, a novel solar-assisted heat pump (SAHP) system with hybrid thermal energy storage is proposed. The system can address the problems of large space requirements and the unstable heating of solar heating systems and tackle the energy-efficient degradation of air source heat pumps (ASHPs) in winter. This study utilized TRNSYS18 software to establish a dynamic simulation model of the system, including the system’s model construction and the control scheme’s design. This performance study focused on analyzing the effects of the collector area and thermal energy storage (TES). The results show that with the increase in the collector area, the collector and power generation efficiencies decrease, and the system performance coefficient improves; the rise in the volume of TES leads to the collector and power generation efficiencies first increasing, and then they tend to stabilize, and the performance coefficient shows a trend of firstly increasing, and then decreasing. In terms of parameter optimization, a target optimization scheme and an evaluation model are constructed. The results indicate that the heating demand for a 116-square-meter building in the Tianjin area is met. The equivalent annual cost (EAC) of the system cost is the lowest, which is CNY 3963, when the collector area of the system is 31 square meters, the heat storage tank (HST) volume is 0.4 cubic meters and the phase-change energy storage (PCES) volume is 0.2 cubic meters. The payback period of the system is 10.59 years, which was compared to that of the ASHP. The further comparison of the economic feasibility of the system in the Lhasa, Shenyang, and Tianjin regions shows that the Lhasa region has the lowest EAC and payback period of CNY 1579 and 8.53 years, respectively, while the payback periods of Tianjin and Shenyang are 10.59 and 10.3 years, with EACs of CNY 3963 and CNY 5096, respectively.

Currently, two-dimensional (2D) materials with intrinsic antiferromagnetism have stimulated research interest due to their insensitivity to external magnetic fields and absence of stray fields. Here, we predict a family of stable transition metal (TM) borides, TMB12 (TM = V, Cr, Mn, Fe) monolayers, by combining TM atoms and B12 icosahedra based on first-principles calculations. Our results show that the four TMB12 monolayers have stable antiferromagnetic (AFM) ground states with large magnetic anisotropic energy. Among them, three TMB12 (TM=V, Cr, Mn) monolayers display an in-plane easy magnetization axis, while the FeB12 monolayer has an out-of-plane easy magnetization axis. Among them, the CrB12 and the FeB12 monolayers are AFM semiconductors with band gaps of 0.13 eV and 0.35 eV, respectively. In particular, the AFM FeB12 monolayer is a spin-polarized AFM material with a Néel temperature of 125 K. Moreover, the electronic and magnetic properties of the CrB12 and the FeB12 monolayers can be modulated by imposing external biaxial strains. Our findings show that the TMB12 monolayers are candidates for designing 2D AFM materials, with potential applications in electronic devices.

Hair whorls and other macroscopic hair patterns are found in a variety of mammalian species, including humans. We show here that Frizzled6 (Fz6), one member of a large family of integral membrane Wnt receptors, controls macroscopic hair patterning in the mouse. Fz6 is expressed in the skin and hair follicles, and targeted deletion of the Fz6 gene produces stereotyped whorls on the hind feet, variable whorls and tufts on the head, and misorientation of hairs on the torso. Embryo chimera experiments imply that Fz6 acts locally to control or propagate the macroscopic hair pattern and that epithelial cells rather than melanocytes are the source of Fz6-dependent signaling. The Fz6 phenotype strongly resembles the wing-hair and bristle patterning defects observed in Drosophila frizzled mutants. These data imply that hair patterning in mammals uses a Fz-dependent tissue polarity system similar to the one that patterns the Drosophila cuticle.

Liquid often exists in the accumulator of the rotary compressor during the process of startup or defrost of air-conditioning systems. Too much liquid entering the compressor cylinder would result in excessive pressure caused by the liquid compression, which is a great threat to the compressor. The liquid return through the liquid-return hole is the key to ensure the stable operation of the compressor. In this paper, the liquid-return characteristics in the liquid-return holes of the accumulator, including the mass-flow rate, liquid velocity and pressure difference between the liquid-return holes, during the startup process of the R290 rotary compressor are numerically investigated. The numerical simulation using the fluent volume of fluid (VOF) method was experimentally validated with the error of 1.55%. The comparison of liquid-return characteristics using different refrigerants is conducted. Effects of refrigerant solubility in the oil, refrigerant/oil-mixture type, liquid-return-hole diameter and compressor frequency on the liquid-return characteristics and liquid shape trough the liquid-return hole are discussed. The results show that the surface tension and viscosity of the liquid are the main factors affecting the liquid-return speed. The liquid-return rate of the refrigerant R290 is slower than that of other refrigerants R22 and R410A. The liquid-return rate increases with the increase in the compressor frequency. We conclude that for air-conditioning systems using R290 as refrigerant, increasing the number of return holes or the hole diameter is necessary to improve the liquid-return characteristics of the compressor. This research will provide theoretical guidance for the optimization of liquid return of rotary compressors using new refrigerants.

SKLB1028 is a novel multi‐target protein kinase inhibitor under investigation for the treatment of FLT3‐ITD mutated acute myeloid leukemia. Based on the preclinical characterization of SKLB1028 metabolism, three drug–drug interaction clinical studies were performed to investigate the effects of itraconazole, rifampin (CYP3A4 inhibitor and inducer, respectively), and gemfibrozil (CYP2C8 inhibitor) on the metabolism of SKLB1028. Fourteen healthy Chinese male subjects were enrolled in each study. In Study 1, subjects were administered a single dose of SKLB1028 (100 mg on days 1 and 11) and multiple doses of itraconazole (200 mg twice daily on day 8 and 200 mg once daily from days 9 to 18). Itraconazole was given with a loading dose on Day 8 and the total administration of itraconazole was 11 days. In Study 2, subjects were administered a single dose of SKLB1028 (100 mg on days 1 and 12) and multiple doses of gemfibrozil (600 mg twice daily from days 8 to 19). In Study 3, subjects were administered a single dose of SKLB1028 (150 mg on days 1 and 15) and multiple doses of rifampin (600 mg once daily from day 8 to 22). Itraconazole increased the AUC and Cmax of SKLB1028 by approximately 28% and 41%, respectively. Compared to the single drug, co‐administration with gemfibrozil increased the AUC of SKLB1028 by ~26% and the Cmax by ~21%. Co‐administration with rifampin reduced the AUC of SKLB1028 by ~30%, while the Cmax did not change significantly. All treatments were well tolerated in all three studies.

The genetic factors that underlie the increasing incidence of diabetes with age are poorly understood. We examined whether telomere length, which is inherited and known to shorten with age, plays a role in the age-dependent increased incidence of diabetes. We show that in mice with short telomeres, insulin secretion is impaired and leads to glucose intolerance despite the presence of an intact β-cell mass. In ex vivo studies, short telomeres induced cell-autonomous defects in β-cells including reduced mitochondrial membrane hyperpolarization and Ca(2+) influx which limited insulin release. To examine the mechanism, we looked for evidence of apoptosis but found no baseline increase in β-cells with short telomeres. However, there was evidence of all the hallmarks of senescence including slower proliferation of β-cells and accumulation of p16(INK4a). Specifically, we identified gene expression changes in pathways which are essential for Ca(2+)-mediated exocytosis. We also show that telomere length is additive to the damaging effect of endoplasmic reticulum stress which occurs in the late stages of type 2 diabetes. This additive effect manifests as more severe hyperglycemia in Akita mice with short telomeres which had a profound loss of β-cell mass and increased β-cell apoptosis. Our data indicate that short telomeres can affect β-cell metabolism even in the presence of intact β-cell number, thus identifying a novel mechanism of telomere-mediated disease. They implicate telomere length as a determinant of β-cell function and diabetes pathogenesis.

Commissural neurons in the mammalian dorsal spinal cord send axons ventrally toward the floor plate, where they cross the midline and turn anteriorly toward the brain; a gradient of chemoattractant(s) inside the spinal cord controls this turning. In rodents, several Wnt proteins stimulate the extension of commissural axons after midline crossing (postcrossing). We found that Wnt4 messenger RNA is expressed in a decreasing anterior-to-posterior gradient in the floor plate, and that a directed source of Wnt4 protein attracted postcrossing commissural axons. Commissural axons in mice lacking the Wnt receptor Frizzled3 displayed anterior-posterior guidance defects after midline crossing. Thus, Wnt-Frizzled signaling guides commissural axons along the anterior-posterior axis of the spinal cord.