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Solar thermal collectors are generally unproductivity at night without sunlight. Radiative cooling, on the other hand, is another renewable technology harvesting coldness from extraterrestrial space and can effectively work nocturnally. Therefore, this study proposes a scheme that integrates the nocturnal radiative cooling mechanism into a solar air collector as a supplementary. Incoming air is heated by the solar absorber during the daytime and cooled down by the glass cover at night. Experimental results indicate that, with an air mass flow rate of 0.03 kg/s, the dual-mode collector (named as PT-RC collector) realized a daytime solar thermal efficiency of 34.2% at zero-reduced temperature (e.g., when the inlet air temperature equals the ambient temperature) and a net radiative cooling power (e.g., when the inlet air temperature equals the ambient temperature) of 27.9 W/m2, which are 72.2% and 2.4 times those of the typical solar air collector. As the air mass flow rate increased from 0.01 to 0.05 kg/s, the two performance indicators lifted from 19.8% to 34.5% and from 16.9 to 33.0 W/m2, respectively. The PT-RC collector shows potential to be applied in four-season regions where heating and cooling are both required throughout the year or tropical zones where cooling is much more desired.

Summary Serotonin receptor 6 (5-HT6R), a typical G protein-coupled receptor (GPCR) mainly expressed in the neurogenic area with constitutive activity, is of particular interest as a promising target for emotional impairment. Here, we found that 5-HT6R was highly expressed in human NSCs and activation of the receptor promoted self-renewal of human NSCs, and thus induced the expansion and folding of human cerebral organoids; dysfunction of receptor or inhibition of its constitutive activity resulted in the premature differentiation of NSCs, which ultimately depleted the NSC pool. The following mechanistic study revealed that EPAC-CREB signaling was involved in 5-HT6R regulation. Furthermore, we showed that mice with genetic deletion of 5-HT6R or knockin A268R mutant presented depression-like behaviors and impaired hippocampal neurogenesis for progressive decrease of the NSC pool. Thus, this study indicates that the modulation of 5-HT6R and its constitutive activity may provide a therapeutic alternative to alleviate depression., Graphical Abstract, Highlights • 5-HT6R regulates human neural stem cell proliferation • The constitutive activity of 5-HT6R is essential for human neural stem cell's multipotency • 5-HT6R modulates neurogenesis of human cerebral organoids • Mice with reduced constitutive activity of 5-HT6R show depression-like behaviors, In this study, Dr. Pei and colleagues demonstrate a potential role of serotonin receptor 5-HT6R constitutive activity in the regulation of neurogenesis and depression-like behaviors in mice. Furthermore, the group found that hNSC-specific activation and inhibition of 5-HT6R bidirectionally regulates hNSC proliferation and expansion and folding of cerebral organoids, leading to changes in neurogenesis.

yeyachun and danshen exist as Chinese patent medicine, Xuemai Tong, and are clearly effective at alleviating liver fibrosis (LF). Previous studies have indicated that triterpenoids from yeyachun (EFT), and phenolic acids from danshen (SMP) are effective in the treatment of LF. The regulation of intestinal flora is an effective method for treating LF. The aim of this study was to investigate the effect of a mixture of EFT and SMP on carbon tetrachloride (CCl4) induced LF. Our results showed the mixture significantly decreased liver damage and fibrosis index, and maintained liver tissue composition, compared to the model group. Moreover, the imbalance of symptoms of intestinal flora was improved. The mixture also caused changes to metabolites of gut flora. Furthermore, the expression of CD68 in liver tissues from the treated groups was significantly decreased when compared to the model group. However, no significant difference was observed from microstructure of gut tissues and LPS concentrations in the serum between mixture treated mice and model mice. This study suggests that the mixture of EFT and SMP had a significant effect on CCl4 induced LF, and the mechanism of this action, at least in part, involved the regulation of intestinal flora and their metabolites.

Taking the frigid outer space as the heat sink, a terrestrial body can cool itself to a sub-ambient temperature via radiative sky cooling (RC) scheme. However, poor seasonal and regional adaptabilities and low cooling power density of the RC technology confine its effective applications only in hot seasons and regions with RC-friendly ambient conditions. Similarly, a solar thermal collector cannot work at night and is of little value when heat is needless. To tackle these challenges, a hybrid solar photothermic and radiative cooling (PT-RC) collector equipped with a rotatable absorber/emitter panel is proposed and experimentally investigated. This dual-mode collector can flexibly switch between PT and RC to match specific energy demands in different scenarios. The daily solar thermal efficiency of the PT-RC system at zero-reduced temperature reached 50.4%, a typical level of flat-plate solar water heating systems. The PT-RC system could not provide cooling energy during most daytime hours. However, the system could easily achieve nighttime cooling, with the cooling power of the collector decreasing from about 60 to 50 W/m2 as the circulated water being continuously cooled down from around 20 to 12 °C. The average nocturnal cooling power of the PT-RC collector ranged from 30.5 to 57.5 W/m2 in a multi-night RC test. This rotatable PT-RC collector offers a new strategy to flexibly deliver heat and coldness in a renewable and environmental-friendly manner and shows the potential of smart thermal management in buildings, vehicles, agriculture, etc.

This study presents a scroll expander modelling methodology for small scale power generation systems by combining scroll geometry and semi-empirical model. Although the semi-empirical model is quite popular, its dependence on several experimentally-determined scroll geometrical and operational parameters makes this approach inflexible for different capacities and operating conditions. Some studies have sought to improve its flexibility in terms of using different working fluids and more accurate empirical parameters, however, those improved models still depend on a considerable number of experimentally-obtained scroll parameters. Therefore, in this study, a practical methodology for a simpler semi-empirical model combined with the operational flexibility of the scroll geometry is presented. Firstly, the flow rates of mainstream and leakage flows are analysed, where a correlation between scroll clearance and pressure ratio is determined. Secondly, a simpler approach to the semi-empirical model of scroll expander is proposed, whereby dependent parameters have been reduced to two parameters by using scroll geometrical calculations. The model is further improved to predict the rotational speed and electricity output by considering the overall friction coefficient of the coupled expander-generator unit. The findings are then compared with the results of an experimental study. The results show that the effective clearance values between scrolls vary according to pressure ratios, increasing from 20 μ m to 34 μ m . Mass flow rate can be predicted within 10% deviation from the experimental results for the same inlet conditions and rotational speed at a transient state. Additionally, considering steady state conditions, modelling results show that the rotational speed and electricity output can also be predicted within 8% and 7.5% of deviation, respectively.

Summary The recent establishment of mammalian haploid embryonic stem cells (ESCs) provides new possibilities for genetic screening and for understanding genome evolution and function. However, the dynamics of mitosis in haploid ESCs is still unclear. Here, we report that the duration of mitosis in haploid ESCs, especially the metaphase, is significantly longer than that in diploid ESCs. Delaying mitosis by chemicals increased self-diploidization of haploid ESCs, while shortening mitosis stabilized haploid ESCs. Taken together, our study suggests that the delayed mitosis of haploid ESCs is associated with self-diploidization., Highlights • Mitosis is prolonged in haploid ESCs, especially in metaphase • Self-diploidization might be associated with the prolonged mitosis of haploid ESCs, In this article, Pei and colleagues found that mitosis is significantly longer in haploid ESCs compared with that of diploid ESCs, especially in metaphase. The longer mitosis of haploid ESCs is also associated with self-diploidization.

Amorphous silicon (a-Si) cells are able to perform better as temperature increases due to the effect of thermal annealing. a-Si cells have great potential to solve or ease the problems of high power temperature coefficient, large thermal stress caused by temperature fluctuation and gradient, and thick layer of conventional crystalline silicon cell-related photovoltaic/thermal (PV/T) collectors. In this paper, an innovative a-Si PV/T system is developed. It is the first time that a-Si cells deposited on stainless steel have been used in a practical PV/T system. The system comprises of two PV/T collectors. In each collector, there are 8 pieces of solar cells in series. Long-term outdoor performance has been monitored. Experimental results on the thermal efficiency Image 1, electrical efficiency Image 2 and I-V characteristic are presented. The peak instantaneous Image 3 was about 42.49% with the maximum Image 4 of 5.92% on April 2, 2017. The daily average Image 5 and Image 6 were 32.8% and 5.58%. Accordingly, Image 7 ,Image 8, Image 9 and Image 10 on October 27 were 43.47%, 5.69%, 38.65% and 5.22 %. During more than half a year operation, no technical failure of the system has been observed. The feasibility of the a-Si PV/T is preliminarily demonstrated by the prototype.

The uniform illumination profile that falls on the PV cell is good for PV output and lifespan, however the flux distribution of the concentrating PV appears to be non-uniform in most cases which is harmful for the overall performance of the concentrating photovoltaic. In order to overcome this disadvantage, a novel asymmetric compound parabolic concentrator concentrating PV with uniform flux distribution is proposed in this paper. A two-dimensional finite element model is built for electrical performance simulation of the concentrating photovoltaic module. The prototype of the concentrating photovoltaic module is manufactured and assembled to conduct the indoor lab experiment under Standard Test Condition to verify the feasibility and reliability of the model. The outdoor experiments are conducted to show the electrical performance of the concentrating photovoltaic module under the real weather condition. Then the model is used to analyze the electrical performance of the PV cell under the flux distribution created by the proposed concentrator. The results show that the electrical performance of the proposed concentrating photovoltaic module is close to that under the uniform flux distribution with the same total radiation level, which confirms that the proposed concentrator is beneficial for the PV output under concentrating illumination due to uniform flux distribution.

Compound parabolic concentrator (CPC) has been gaining ever-increasing attention from academic researchers and industrial developers owing to its stationary feature for solar energy collection with a higher efficiency. As a low concentration concentrator with a larger acceptance angle and without a tracking requirement, it is an attractive solution to improve the system performance and reduce the cost of photovoltaic (PV) system, solar thermal system, daylighting and lighting systems, etc. This study will present a comprehensive and up-to-date review of its design principles for miscellaneous configurations, applications, performance predictions and technological advances. Numerous technically focused studies since 2000 will be introduced and summarized. Finally, the outlook focusing on CPC designs and improvements will be proposed.