Metal binding to microbial extracellular polymeric substances (EPS) greatly influences the distribution of heavy metals in microbial aggregates, soil and aquatic systems in nature. In this work, the ...thermodynamic characteristics of the binding between aqueous metals (with copper ion as an example) and EPS of activated sludge were investigated. Isothermal titration calorimetry was employed to estimate the thermodynamic parameters for the binding of Cu2+ onto EPS, while three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy with parallel factor analysis was used for quantifying the complexation of Cu2+ with the EPS. The binding mechanisms were further explored by X-ray absorption fine structure (XAFS) and Fourier transform infrared (FTIR) spectroscopy analysis. The results show that the proteins and humic substances in EPS were both strong ligands for Cu2+. The binding capacity N, binding constant K, binding enthalpy ΔH were calculated as 5.74 × 10−2 mmol/g, 2.18 × 105 L/mol, and −11.30 kJ/mol, respectively, implying that such a binding process was exothermic and thermodynamically favorable. The binding process was found to be driven mainly by the entropy change of the reaction. A further investigation shows that Cu2+ bound with the oxygen atom in the carboxyl groups in the EPS molecules of activated sludge. This study facilitates a better understanding about the roles of EPS in protecting microbes against heavy metals.
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► Thermodynamic characteristics of binding of Cu2+ to EPS are investigated. ► The binding process is exothermic and thermodynamically favorable. ► Cu2+ binds with the O atom in the carboxyl groups in EPS.
A
bstract
The affine Yangian of
gl
1
is isomorphic to the universal enveloping algebra of
W
1
+
∞
and can serve as a building block in the construction of new vertex operator algebras. In 1, a ...two-parameter family generalization of
N
= 2 supersymmetric
W
∞
algebra was constructed by “gluing” two affine Yangians of
gl
1
using operators that transform as (□,
□
¯
) and (
□
¯
, □) w.r.t. the two affine Yangians. In this paper we realize a similar (but non-isomorphic) two-parameter gluing construction where the gluing operators transform as (□, □) and (
□
¯
,
□
¯
) w.r.t. the two affine Yangians. The corresponding representation space consists of pairs of plane partitions connected by a common leg whose cross-section takes the shape of Young diagrams, offering a more transparent geometric picture than the previous construction.
Effective solid‐state interfacial contact of both the cathode and lithium metal anode with the solid electrolyte (SE) are required to improve the performance of solid‐state lithium metal batteries ...(SSBs). Electro–chemo–mechanical coupling (ECMC) strongly affects the interfacial stability of SSBs. On one hand, mechanical stress strongly influences interfacial contact and causes side reactions. On the other hand, electrochemical reactions such as lithium deposition cause mechanical deformation and stress at electrode/SE interfaces. To solve the degradation/failure problems of interfaces and provide guidelines to construct high‐performance SSBs, the ECMC at electrode/SE interfaces should be comprehensively investigated. In this review, the problems associated with ECMC at electrode/SE interfaces are summarized. The interfacial degradation/failure mechanisms, including the contact and electrochemical stability of interfaces, are introduced. Mechanical factors affecting interfacial contact and lithium deposition are highlighted. Experimental observation and computational analysis methods for electrode/SE interfaces are then summarized. Strategies to construct stable electrode/SE interfaces, such as assembling stress and wetting layers to improve interfacial contact, 3D SE structure, and plating stress relief to suppress lithium dendrite formation, are reviewed. The remaining challenges to better understanding ECMC and related solutions to aid SSB development are discussed.
The failure mechanisms of electrode/solid electrolyte (SE) interfaces in solid‐state lithium metal batteries (SSBs) involve multiscale and multiphysical field coupling. Various in situ observation technologies and corresponding theoretical approaches have been used to investigate the degradation mechanism of SSBs. Based on the experimental and theoretical results, well‐established solutions are explored to construct stable electrode/SE interfaces in SSBs.
Two-dimensional materials provide extraordinary opportunities for exploring phenomena arising in atomically thin crystals. Beginning with the first isolation of graphene, mechanical exfoliation has ...been a key to provide high-quality two-dimensional materials, but despite improvements it is still limited in yield, lateral size and contamination. Here we introduce a contamination-free, one-step and universal Au-assisted mechanical exfoliation method and demonstrate its effectiveness by isolating 40 types of single-crystalline monolayers, including elemental two-dimensional crystals, metal-dichalcogenides, magnets and superconductors. Most of them are of millimeter-size and high-quality, as shown by transfer-free measurements of electron microscopy, photo spectroscopies and electrical transport. Large suspended two-dimensional crystals and heterojunctions were also prepared with high-yield. Enhanced adhesion between the crystals and the substrates enables such efficient exfoliation, for which we identify a gold-assisted exfoliation method that underpins a universal route for producing large-area monolayers and thus supports studies of fundamental properties and potential application of two-dimensional materials.
The huge land areas in China provide highly diverse habitats for macrofungi. Of these macrofungi, many are directly related to people’s daily life and have been utilized by ancient Chinese for at ...least 6800 years. In this study, we evaluate the current known resource diversity of Chinese macrofungi. A total of 1662 taxa are summarized, and all species names and their authorities have been checked and corrected according to authentic mycological databases. Among the 1662 taxa, 1020, 692, and 480 are considered to be edible, medicinal and poisonous mushrooms, respectively. A few of edible macrofungi in China are commonly used for commercial production. All known medicinal functions are labeled for medicinal species. The most common medicinal functions possessed by Chinese macrofungi are antitumor or anticancer, followed by antioxidant and antimicrobial. A total of 277 Chinese macrofungi are edible simultaneously with certain medicinal functions and without known toxicity. These species could be treated as “Gold Mushrooms”. Contrarily, 193 edible and/or medicinal species are also recognized as poisonous mushrooms. To avoid poisoning caused by these species, ingestion either in a proper way or in small amounts is important. However, the mycotoxins metabolized by these poisonous species could be a huge wealth of natural products yet to be explored. How to utilize these Chinese macrofungal resources is a critical to benefit humans worldwide.
The ability to control thermal radiation is of fundamental importance for a wide range of applications. Nanophotonic structures, where at least one of the structural features are at a wavelength or ...sub-wavelength scale, can have thermal radiation properties that are drastically different from conventional thermal emitters, and offer exciting opportunities for energy applications. Here we review recent developments of nanophotonic control of thermal radiation, and highlight some exciting energy application opportunities, such as daytime radiative cooling, thermal textile, and thermophotovoltaic systems that are enabled by nanophotonic structures.
Defects have been found to enhance the electrocatalytic performance of NiFe‐LDH for oxygen evolution reaction (OER). Nevertheless, their specific configuration and the role played in regulating the ...surface reconstruction of electrocatalysts remain ambiguous. Herein, cationic vacancy defects are generated via aprotic‐solvent‐solvation‐induced leaking of metal cations from NiFe‐LDH nanosheets. DFT calculation and in situ Raman spectroscopic observation both reveal that the as‐generated cationic vacancy defects tend to exist as VM (M=Ni/Fe); under increasing applied voltage, they tend to assume the configuration VMOH, and eventually transform into VMOH‐H which is the most active yet most difficult to form thermodynamically. Meanwhile, with increasing voltage the surface crystalline Ni(OH)x in the NiFe‐LDH is gradually converted into disordered status; under sufficiently high voltage when oxygen bubbles start to evolve, local NiOOH species become appearing, which is the residual product from the formation of vacancy VMOH‐H. Thus, we demonstrate that the cationic defects evolve along with increasing applied voltage (VM → VMOH → VMOH‐H), and reveal the essential motif for the surface restructuration process of NiFe‐LDH (crystalline Ni(OH)x → disordered Ni(OH)x → NiOOH). Our work provides insight into defect‐induced surface restructuration behaviors of NiFe‐LDH as a typical precatalyst for efficient OER electrocatalysis.
Along with increasing voltage during the OER process, the structural evolution of cationic defects within NiFe‐LDH, where the simple vacancy VM changes to VMOH and then to the most reactive VMOH‐H, and the surface restructuration, where surface crystalline Ni(OH)x is converted to disordered Ni(OH)x and then to the surface local NiOOH species, are voltage‐regulated concurrent events defining the eventual catalytic performance of the precatalyst.
This Escherichia coli-produced bivalent HPV 16 and 18 vaccine was well tolerated and effective against HPV 16 and 18 associated high-grade genital lesions and persistent infection in interim analysis ...of this phase 3 trial. We now report data on long-term efficacy and safety after 66 months of follow-up.
This phase 3, double-blind, randomised, controlled trial was done in five study sites in China. Eligible participants were women aged 18–45 years, with intact cervix and 1–4 lifetime sexual partners. Women who were pregnant or breastfeeding, had chronic disease or immunodeficiency, or had HPV vaccination history were excluded. Women were stratified by age (18–26 and 27–45 years) and randomly (1:1) allocated by software (block randomisation with 12 codes to a block) to receive three doses of the E coli-produced HPV 16 and 18 vaccine or hepatitis E vaccine (control) and followed-up for 66 months. The primary outcomes were high-grade genital lesions and persistent infection (longer than 6 months) associated with HPV 16 or 18 in the per-protocol susceptible population. This trial was registered with ClinicalTrials.gov, NCT01735006.
Between Nov 22, 2012, and April 1, 2013, 8827 women were assessed for eligibility. 1455 women were excluded, and 7372 women were enrolled and randomly assigned to receive the HPV vaccine (n=3689) or control (n=3683). Vaccine efficacy was 100·0% (95% CI 67·2–100·0) against high-grade genital lesions (0 0% of 3310 participants in the vaccine group and 13 0·4% of 3302 participants in the control group) and 97·3% (89·9–99·7) against persistent infection (2 0·1% of 3262 participants in the vaccine group and 73 2·2% of 3271 participants in the control group) in the per-protocol population. Serious adverse events occurred at a similar rate between vaccine (267 7·2% of 3691 participants) and control groups (290 7·9% of 3681); none were considered related to vaccination.
The E coli-produced HPV 16 and 18 vaccine was well tolerated and highly efficacious against HPV 16 and 18 associated high-grade genital lesions and persistent infection and would supplement the global HPV vaccine availability and accessibility for cervical cancer prevention.
National Natural Science Foundation of China, National Key R&D Program of China, Fujian Provincial Project, Fundamental Funds for the Central Universities, Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences, and Xiamen Innovax.
A novel SARS-related coronavirus (SARS-CoV-2) has recently emerged as a serious pathogen that causes high morbidity and substantial mortality. However, the mechanisms by which SARS-CoV-2 evades host ...immunity remain poorly understood. Here, we identified SARS-CoV-2 membrane glycoprotein M as a negative regulator of the innate immune response. We found that the M protein interacted with the central adaptor protein MAVS in the innate immune response pathways. This interaction impaired MAVS aggregation and its recruitment of downstream TRAF3, TBK1, and IRF3, leading to attenuation of the innate antiviral response. Our findings reveal a mechanism by which SARS-CoV-2 evades the innate immune response and suggest that the M protein of SARS-CoV-2 is a potential target for the development of SARS-CoV-2 interventions.
Layered double hydroxides (LDHs) are among the most active and studied catalysts for the oxygen evolution reaction (OER) in alkaline electrolytes. However, previous studies have generally either ...focused on a small number of LDHs, applied synthetic routes with limited structural control, or used non‐intrinsic activity metrics, thus hampering the construction of consistent structure–activity‐relations. Herein, by employing new individually developed synthesis strategies with atomic structural control, we obtained a broad series of crystalline α‐MA(II)MB(III) LDH and β‐MA(OH)2 electrocatalysts (MA=Ni, Co, and MB=Co, Fe, Mn). We further derived their intrinsic activity through electrochemical active surface area normalization, yielding the trend NiFe LDH > CoFe LDH > Fe‐free Co‐containing catalysts > Fe‐Co‐free Ni‐based catalysts. Our theoretical reactivity analysis revealed that these intrinsic activity trends originate from the dual‐metal‐site nature of the reaction centers, which lead to composition‐dependent synergies and diverse scaling relationships that may be used to design catalysts with improved performance.
Catalytic activities for oxygen evolution on crystalline 3d transition metal layered double hydroxides are derived using electrochemical surface area based normalization. Density functional calculations reveal a dual‐metal‐site feature of the reaction centers that provides opportunities to design new catalysts with improved performance.
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