The biotic enzymatic reduction of mercury II Hg(II) to elemental Hg Hg(0) is an important pathway for Hg detoxification in natural ecosystems. However, the mechanisms of Hg(II) volatilization and ...resistance in fungi have not been understood completely. In the present study, we investigated the mechanisms of Hg(II) volatilization and resistance in the fungus Lecythophora sp. DC-F1. Hg(II) volatilization occurred during the investigation via the reduction of Hg(II) to Hg(0) in DC-F1. Comparative transcriptome analyses of DC-F1 revealed 3439 differentially expressed genes under 10 mg/L Hg(II) stress, among which 2770 were up-regulated and 669 were down-regulated. Functional enrichment analyses of genes and pathways further suggested that the Hg(II) resistance of DC-F1 is a multisystem collaborative process with three important transcriptional responses to Hg(II) stress: a mer-mediated Hg detoxification system, a thiol compound metabolism, and a cell reactive oxygen species stress response system. The phylogenetic analysis of merA protein homologs suggests that the Hg(II) reduction by merA is widely distributed in fungi. Overall, this study provides evidence for the reduction of Hg(II) to Hg(0) in fungi via the mer-mediated Hg detoxification system and offers a comprehensive explanation for its role within Hg biogeochemical cycling. These findings offer a strong theoretical basis for the application of fungi in the bioremediation of Hg-contaminated envionments.
Display omitted
•Volatilization of Hg(II) in fungus DC-F1 via the reduction of Hg(II) to Hg(0)•Mer detoxification system is responsible for reduction of Hg(II) in DC-F1.•Mercuric reductase (merA) is widely distributed in fungi.•Thiol compounds play important role in cellular detoxification of Hg(II).
In this study, we built a perovskite solar cells(PSCs) model with a Au/CuSCN/CH3NH3Sn1−xPbxI3/TiO2/FTO glass structure using the SCAPS program and use polynomial fitting to obtain the relationship ...between the conduction/valence bands of CH3NH3Sn1−xPbxI3 and the x value, which is more complex and accurate than that in any previous research. The influences of thickness, electron and hole mobilities, relative permittivity, effective conduction band density, effective valence band density, and the value of x on the solar cell performance are analyzed. Furthermore, we simulate the situation where the doping concentration changes with the absorption layer depth of the device and a special bandgap is formed. The power conversion efficiency of the device improves from 19.96% to 20.52%, with an open-circuit voltage of 0.776 V, a short-circuit current of 33.79 mA/cm2, and a filling factor of 77.39% when double gradient doping is performed. The application value of gradient doping in the device absorption layer is obtained.
The peptide-derived self-assembly platform has attracted increasing attention for its great potential to develop into multitargeting nanomedicines as well as its inherent biocompatibility and ...biodegradability. However, their clinical application potentials are often compromised by low stability, weak membrane penetrating ability, and limited functions. Herein, inspired by a natural protein from the seeds of Luffa cylindrica, we engineered via epitope grafting and structure design a hybrid peptide-based nanoplatform, termed Lupbin, which is capable of self-assembling into a stable superstructure and concurrently targeting multiple protein–protein interactions (PPIs) located in cytoplasm and nuclei. We showed that Lupbin can efficiently penetrate cell membrane, escape from early endosome-dependent degradation, and subsequently disassemble into free monomers with wide distribution in cytosol and nucleus. Importantly, Lupbin abrogated tumor growth and metastasis through concurrent blockade of the Wnt/β-catenin signaling and reactivation of the p53 signaling, with a highly favorable in vivo biosafety profile. Our strategy expands the application of self-assembled nanomedicines into targeting intercellular PPIs, provides a potential nanoplatform with high stability for multitargeted cancer therapy, and likely reinvigorates the development of peptide-based therapeutics for the treatment of different human diseases including cancer.
In this work, full‐color and stable white organic afterglow materials with outstanding water, organic solvents, and temperature resistances have been developed for the first time by embedding the ...selected polycyclic aromatic hydrocarbons into melamine‐formaldehyde polymer via solution polymerization. The afterglow quantum yields and lifetimes of the resulting polymer films were up to 22.7 % and 4.83 s, respectively, under ambient conditions. For the coronene‐doped sample, its afterglow color could be linearly tuned between yellow and blue by adjusting the temperature, and it could still emit an intense blue afterglow with a lifetime of 0.68 s at 440 K. Moreover, the films showed a bright and stable white afterglow at 370 K with a lifetime of 2.80 s and maintained an excellent afterglow performance after soaking in water and organic solvents for more than 150 days. In addition, the application potential of the polymer films in information encryption and anti‐counterfeiting was also demonstrated.
Full‐color and stable white organic afterglow materials have been developed by embedding the selected polycyclic aromatic hydrocarbons into a melamine‐formaldehyde polymer by solution polymerization. Their afterglow quantum yields and lifetimes were up to 22.7 % and 4.83 s, respectively. Moreover, the resulting polymer films showed a color‐tunable dual‐mode organic afterglow and outstanding water, organic solvents, and temperature resistances.
In recent years, inorganic perovskite solar cells (PSCs) based on CsPbIsub.3 have made significant progress in stability compared to hybrid organic-inorganic PSCs by substituting the volatile organic ...component with Cs cations. However, the cubic perovskite structure of α-CsPbIsub.3 changes to the orthorhombic non-perovskite phase at room temperature resulting in efficiency degradation. The partial substitution of an I ion with Br ion benefits for perovskite phase stability. Unfortunately, the substitution of Br ion would enlarge bandgap reducing the absorption spectrum range. To optimize the balance between band gap and stability, introducing and optimizing the spatial bandgap gradation configuration is an effective method to broaden the light absorption and benefit the perovskite phase stability. As the bandgap of the CsPb(Isub.1-xBrsub.x)sub.3 perovskite layer can be adjusted by I-Br composition engineering, the performance of CsPb(Isub.1-xBrsub.x)sub.3 based PSCs with three different spatial variation Br doping composition profiles were investigated. The effects of uniform doping and gradient doping on the performance of PSCs were investigated. The results show that bandgap (Eg) and electron affinity(χ) attributed to an appropriate energy band offset, have the most important effects on PSCs performance. With a positive conduction band offset (CBO) of 0.2 eV at the electron translate layer (ETL)/perovskite interface, and a positive valence band offset (VBO) of 0.24 eV at the hole translate layer (HTL)/perovskite interface, the highest power conversion efficiency (PCE) of 22.90% with open-circuit voltage (Vsub.OC) of 1.39 V, short-circuit current (Jsub.SC) of 20.22 mA/cmsup.2 and filling factor (FF) of 81.61% was obtained in uniform doping CsPb(Isub.1-xBrsub.x)sub.3 based PSCs with x = 0.09. By carrying out a further optimization of the uniform doping configuration, the evaluation of a single band gap gradation configuration was investigated. By introducing a back gradation of band gap directed towards the back contact, an optimized band offset (front interface CBO = 0.18 eV, back interface VBO = 0.15 eV) was obtained, increasing the efficiency to 23.03%. Finally, the double gradient doping structure was further evaluated. The highest PCE is 23.18% with Vsub.OC close to 1.44 V, Jsub.SC changes to 19.37 mA/cmsup.2 and an FF of 83.31% was obtained.
Serpentinite-derived components play an important role in chemical cycling in subduction zones. However, it is difficult to identify recycled serpentinite in subarc mantle due to the overprinting of ...other slab components, and how serpentinite contributes to arc magmatism is poorly understood. Here we report Mo and Mg isotopic compositions of Early Paleozoic Qushiang arc mafic rocks in the East Kunlun orogen. The Qushiang mafic rocks have variable δ98Mo values of −0.50‰ to 0.78% and δ26Mg values of −0.31‰ to −0.05‰. These features, combining with arc-type trace element distribution patterns, enriched SrNd isotopes, and variable zircon HfO isotopes, suggest the incorporation of different subducting components in their mantle source. Some mafic rocks show high δ98Mo values together with low Mo/Ce ratios and enriched SrNd isotopes, suggesting the contribution of subducted sediment (SSD)-derived melts. Additionally, light Mo isotopes are also identified in mafic rocks, which are closely related to depleted SrNd isotopes. These features are mainly inherited from the subducted dehydrated altered oceanic crust (SAOC)-derived melts. More importantly, the coexisting and significantly high δ26Mg and δ98Mo values of these rocks could not be explained by the SSD or SAOC components, but require serpentinite components in the subarc mantle source. Our study reveals that combined Mo and Mg isotopic studies are potential tools for tracing serpentinite recycling, and provides new insight into the mechanisms by which different subducting components contribute to arc magmatism.
In this paper, crosslinked polyacrylate latex with tertiary amine groups (ACLN) and base latex without tertiary amine groups (ACL) were prepared by emulsion polymerization using butyl acrylate as the ...monomer and 1,4-butanediol dimethacrylate as the crosslinker. Composite resins of polyvinyl chloride (PVC), ACL/PVC and ACLN/PVC, were prepared by suspension polymerization of vinyl chloride in a 20 L high-pressure reactor by adding ACL and ACLN as modifiers. The inner pressure of the reactor and initiator concentration as a function of reaction time during suspension polymerization were studied. Morphology of resin particles, processing properties, thermal stability and mechanical properties of ACL/PVC and ACLN/PVC products were investigated. A commercial PVC product named PVC-SG5 was used as the control sample for comparison. It was found that compared with typical PVC-SG5 preparation, ACL/PVC fabrication took less time while initiator concentrations needed to be increased to 2400 ppm in ACLN/PVC preparation in order to complete the polymerization within the same time. Reactor scaling occurred during ACL/PVC preparation, but could be avoided in ACLN/PVC preparation owing to the hydrophilicity of ACLN. The morphology of ACL/PVC and ACLN/PVC particles was smooth microspheres and mosaic particle shapes, respectively, the diameter of which were all smaller than PVC-SG5 particles. The covalent-bonding existing in ACL/PVC and ACLN/PVC, and ionic-bond formation of quaternary ammonium in ACLN/PVC composite resins, between tertiary amine groups in ACLN and chlorine atoms in PVC, contributed to the dramatic increase in thermal stability. ACLN/PVC exhibited the shortest plasticizing time and the longest elongation at break, followed by ACL/PVC. The toughness of both ACL/PVC and ACLN/PVC were greatly enhanced without affecting the tensile strength and softening temperature of the resin. Thus, three issues, namely, low thermal stability, low toughness and reactor scaling during polymerization of PVC have been comprehensively solved by introducing ACLN to PVC through a one-pot method.
Display omitted
•Polyacrylate latex with tertiary amine groups (ACLN) was used to modify PVC in-situ.•Impact strength of PVC was strengthened by ACLN dramatically.•Thermal stability of ACLN/PVC was much higher than that of PVC.•The introduction of ACLN reduced reactor scaling during suspension polymerization.•Three issues have been comprehensively solved through a one-pot method.
Outer-layer shape-stabilized phase change roof is a building roof construction that laying shape-stabilized phase change material (PCM) on the surface of the roof. The peak temperature and the ...decrement factor of the roof inner surface can be greatly reduced. In this study, the thermal insulation properties of this structure in five climate regions of China are studied using CFD numerical simulation. By comparing with roof without PCM, the optimal phase transition temperature for each climate region is analyzed. The results show that the phase transition temperature of the PCM in the roof increases linearly with the increase of the average outdoor solar air temperature. The optimum phase transition temperatures in severe cold region, cold region, hot summer and cold winter region, hot summer and warm winter region, and mild region are 31~33°C, 34~36°C,36~38°C, 34~36°C, and 29~31°C, respectively. The corresponding decrement factors of the inner surface of the roof under the optimum phase transition temperature are 0.033, 0.030, 0.033, 0.028 and 0.026, respectively. Compared with roof without PCM layer, the decrement factors are decreased by 85.90%, 87.12%, 85.78%, 87.83%, and 88.79%, and the peak temperatures of inner surface are decreased by 3.7, 4.0, 3.9, 3.8, and 3.7°C, respectively.
Metformin is accepted as a first-line drug for the therapy of Type 2 diabetes (T2D), while its mechanism is still controversial. In the present study, by taking advantage of mouse model of ...high-fat-diet (HFD)-induced obesity and primary mouse hepatocytes (PMHCs) as well as human hepatocyte L02 cell line, we aimed to investigate the involvement of SIRTs during the application of metformin for the therapy of T2D. Our data evidenced that during HFD-induced obesity, there was elevation of nucleus protein acetylation. Analysis of liver tissue showed that among all SIRT members, SIRT6 expression was significantly down-regulated during HFD feeding, which was sustained to regular level with metformin administration. Our result also showed that SIRT6 suppressed intracellular oxidative stress upon FAs stimulation in PMHCs and L02 cells. Mechanistically, SIRT6, but not SIRT1 promoted PGC-1α expression. We further prove that ENDOG is downstream of PGC-1α. In addition, we evidenced that ENDOG protects hepatocytes from lipid-induced oxidative stress, and down-regulation of Endog blunted the protective role of metformin in defending against FAs-induced oxidative stress. Our study established a novel mechanism of metformin in counteracting lipid-induced hepatic injury via activating SIRT6/PGC-1α/ENDOG signaling, thus providing novel targets of metformin in the therapy of T2D.