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Solid strong base catalysts are highly attractive for diverse reactions owing to their advantages of neglectable corrosion, facile separation, and environmental friendliness. However, their widespread applications are impeded by basic components aggregation and low stability. In this work, we fabricate single calcium atoms on graphene (denoted as Ca1/G) by use of a redox strategy for the first time, producing solid strong base catalyst with high activity and stability. The precursor Ca(NO3)2 is first reduced to CaO at 400 °C by the support graphene, forming CaO/G with conventional basic sites, and the subsequent reduction at 850 °C results in the generation of Ca1/G with atomically dispersed Ca. Various characterizations reveal that Ca single atoms are anchored on graphene in tetra-coordination (Ca–C2–N2) where N is in situ doped from Ca(NO3)2. The atomically dispersed Ca, along with their anchoring on the support, endow Ca1/G with high activity and stability toward the transesterification reaction of ethylene carbonate with methanol. The turnover frequency value reaches 128.0 h−1 on Ca1/G, which is much higher than the traditional counterpart CaO/G and various reported solid strong bases (2.9–46.2 h−1). Moreover, the activity of Ca1/G is well maintained during 5 cycles, while 60% of activity is lost for the conventional analogue CaO/G due to the leaching of Ca.

In order to solve the problems of high pollutant concentration and low treatment efficiency of sewage in expressway service area, an integrated A2O-MBR reactor was used to treat the target sewage. On the basis of successful start-up of the reactor, the pollutant removal performances of A2O-MBR process under the influence of different DO, nitrification reflux ratio and C/N were studied. The results showed that A2O-MBR could obtain the best pollutant removal effect under the condition of DO mass concentration of 4 mg/L, nitrification reflux ratio of 300% and C/N of 6. The removal rates of COD, BOD5 and TP were about 90.57%, 93.75% and 93.00%. When the reactor was stable,the effluent mass concentrations of NH4+-N and SS were about 4.2 mg/L and 4.5 mg/L, respectively. The effluent indicators all met the requirements of flushing and vehicle flushing in the Reuse of Urban Recycling Water-Water Quality Standard for Urban Miscellaneous Use(GB/T 18920-2020). The integrated A2O-MBR could reduce the pollution degree of membrane components, thus reducing the maintenance and operation cost of the system, and could provide a reference for the actual engineering transformation of sewage treatment in the service area of highways.

Lipid droplets (LDs) are dynamic organelles that store neutral lipids and are closely linked to obesity. Previous studies have suggested that Lycium barbarum polysaccharide (LBP) supplements can ameliorate obesity, but the underlying mechanisms remain unclear. In this study, we hypothesize that LBP alleviates LD accumulation in adipose tissue (AT) by inhibiting fat-specific protein 27 (Fsp27) through an activating transcription factor-6 (ATF6)/small-molecule sirtuin 1 (SIRT1)-dependent mechanism. LD accumulation in AT is induced in high-fat diet (HFD)-fed mice, and differentiation of 3T3-L1 preadipocytes (PAs) is induced. The ability of LBP to alleviate LD accumulation and the possible underlying mechanism are then investigated both in vivo and in vitro. The influences of LBP on the expressions of LD-associated genes ( ATF6 and Fsp27) are also detected. The results show that HFD and PA differentiation markedly increase LD accumulation in ATs and adipocytes, respectively, and these effects are markedly suppressed by LBP supplementation. Furthermore, LBP significantly activates SIRT1 and decreases ATF6 and Fsp27 expressions. Interestingly, the inhibitory effects of LBP are either abolished or exacerbated when ATF6 is overexpressed or silenced, respectively. Furthermore, SIRT1 level is transcriptionally regulated by LBP through opposite actions mediated by ATF6. Collectively, our findings suggest that LBP supplementation alleviates obesity by ameliorating LD accumulation, which might be partially mediated by an ATF6/SIRT1-dependent mechanism.

[ Objective ] Chlorophyllide a oxygenase ( CAO ) is a key enzyme in the formation of chlorophyll b. Cloning and expression analysis of CAO genes may be helpful in exploring their function in regulating leaf color variation of Cymbidium hybrid. [ Methods ] ChCAO gene was cloned from leaves of Cymbidium hybrid by RACE and RT-PCR. ChCAO was analyzed for structure characteristics , physicochemical prop- erties , sequence alignment , and phylogenetic relationship. The expression of ChCAO in different tissues and leaves of K21-3 were analyzed by qRT-PCR. Meanwhile , ChCAO expression was silenced by VIGS technology. [ Results ] The results showed that ChCAO coding region was 1 608 bp , encoding 535 amino acids. ChCAO was closely related to Cymbidium sinense , which belonged to genus Cymbidium . qRT-PCR assay showed that the expression of ChCAO was the highest in leaves and the lowest in roots. The expres- sion of ChCAO in K21 leaves was significantly higher than that of K21-3. The VIGS silencing vector of ChCAO gene was constructed and transferred to tobacco. The viral vector was successfully invaded the to- bacco , and the old leaves of tobacco were turned yellow , while chlorophyll content and expression of ChCA O gene were reduced. [ Conclusion ] The ChCAO gene was obtained and its function was preliminarily characterized , which are helpful for the understanding of the formation of leaf art in Cymbidium hybrid.

Temperature-swing adsorption (TSA) is an effective technique for CO2 capture, but the temperature swing procedure is energy-intensive. Herein, we report a low-energy-consumption system by combining passive radiative cooling and solar heating for the uptake of CO2 on commercial activated carbons (CACs). During adsorption, the adsorbents are coated with a layer of hierarchically porous poly(vinylidene fluoride-co-hexafluoropropene) [P(VdF-HFP)HP], which cools the adsorbents to a low temperature under sunlight through radiative cooling. For desorption, CACs with broad absorption of the solar spectrum are exposed to light irradiation for heating. The heating and cooling processes are completely driven by solar energy. Adsorption tests under mimicked sunlight using the CACs show that the performance of this system is comparable to that of the traditional ones. Furthermore, under real sunlight irradiation, the adsorption capacity of the CACs can be well maintained after multiple cycles. The present work may inspire the development of new temperature swing procedures with little energy consumption.