Exploring high‐efficiency and stable halide perovskite‐based photocatalysts for the selective reduction of CO2 to methane is a challenge because of the intrinsic photo‐ and chemical instability of ...halide perovskites. In this study, halide perovskites (Cs3Bi2Br9 and Cs2AgBiBr6) were grown in situ in mesoporous TiO2 frameworks for an efficient CO2 reduction. Benchmarked CH4 production rates of 32.9 and 24.2 μmol g−1 h−1 with selectivities of 88.7 % and 84.2 %, were achieved, respectively, which are better than most reported halide perovskite photocatalysts. Focused ion‐beam sliced‐imaging techniques were used to directly image the hyperdispersed perovskite nanodots confined in mesopores with tunable sizes ranging from 3.8 to 9.9 nm. In situ X‐ray photoelectronic spectroscopy and Kelvin probe force microscopy showed that the built‐in electric field between the perovskite nanodots and mesoporous titania channels efficiently promoted photo‐induced charge transfer. Density functional theory calculations indicate that the high methane selectivity was attributed to the Bi‐adsorption‐mediated hydrogenation of *CO to *HCO that dominates CO desorption.
Halide perovskites (Cs3Bi2Br9, Cs2AgBiBr6) are grown in situ in a mesoporous titania framework for efficient CO2 reduction reaction (CO2RR). A benchmarked production rate of CH4 (32.9 and 24.2 μmol g−1 h−1) is achieved with selectivity values of 88.7 % and 84.2 %, respectively. In situ X‐ray photoelectronic spectroscopy and Kelvin probe force microscopy reveal that the inner surface built‐in electric field between the perovskite nanodots and mesoporous titania channels can efficiently promote photo‐induced charge transfer.
Low‐dimensional materials have been long sought after for their particular electromagnetic (EM) functions, with promising applications in EM wave absorbing and shielding, communicating and imaging, ...sensing and detecting, driving and actuating, etc. Herein, across the whole EM spectrum, low‐dimensional EM functional materials and devices are highly focused on. The crystal engineering and function‐guiding features addressed relate to crystal and electronic structures, EM responses and properties, energy conversion, as well as EM wave absorbing and shielding. Moreover, insight is given into this rapidly broadening field, the main challenges are proposed and future directions are predicted.
Electromagnetic response and energy conversion for functions and devices of low‐dimensional materials are systematically summarized. The crystal and electronic structures are described, and crystal engineering and function‐guiding features are highlighted. Importantly, the electromagnetic functions and devices are demonstrated with a prediction of the most prospective opportunities and directions for the future.
In conjunction with the classical functions of regulating intestinal, bone, and kidney calcium and phosphorus absorption, as well as bone mineralization of vitamin D, the population-based association ...between low vitamin D status and increased cancer risk is now generally accepted. Inflammation is causally related to oncogenesis. It is widely thought that vitamin D plays an important role in the modulation of the inflammation system by regulating the production of inflammatory cytokines and immune cells, which are crucial for the pathogenesis of many immune-related diseases. Mechanistic studies have shown that vitamin D influences inflammatory processes involved in cancer progression, including cytokines, prostaglandins, MAP kinase phosphatase 5 (MKP5), the nuclear factor kappa B (NF-κB) pathway, and immune cells. Multiple studies have shown that vitamin D has the potential to inhibit tumor development by interfering with the inflammation system. The present review summarizes recent studies of the mechanisms of vitamin D on regulating the inflammation system, which contributes to its potential for cancer prevention and therapy. This review helps answer whether inflammation mediates a causal relationship between vitamin D and tumorigenesis.
To investigate the clinical and imaging characteristics of computed tomography (CT) in novel coronavirus pneumonia (NCP) caused by SARS-CoV-2.
A retrospective analysis was performed on the imaging ...findings of patients confirmed with COVID-19 pneumonia who had chest CT scanning and treatment after disease onset. The clinical and imaging data were analyzed.
Fifty patients were enrolled, including mild type in nine, common in 28, severe in 10 and critically severe in the rest three. Mild patients (29 years) were significantly (P<0.03) younger than either common (44.5 years) or severe (54.7) and critically severe (65.7 years) patients, and common patients were also significantly (P<0.03) younger than severe and critically severe patients. Mild patients had low to moderate fever (<39.1 °C), 49 (98%) patients had normal or slightly reduced leukocyte count, 14 (28%) had decreased counts of lymphocytes, and 26 (52%) patients had increased C-reactive protein. Nine mild patients were negative in CT imaging. For all the other types of NCP, the lesion was in the right upper lobe in 30 cases, right middle lobe in 22, right lower lobe in 39, left upper lobe in 33 and left lower lobe in 36. The lesion was primarily located in the peripheral area under the pleura with possible extension towards the pulmonary hilum. Symmetrical lesions were seen in 26 cases and asymmetrical in 15. The density of lesion was mostly uneven with ground glass opacity as the primary presentation accompanied by partial consolidation and fibrosis.
CT imaging presentations of NCP are mostly patchy ground glass opacities in the peripheral areas under the pleura with partial consolidation which will be absorbed with formation of fibrotic stripes if improved. CT scanning provides important bases for early diagnosis and treatment of NCP.
Highlights
The role of electron transport characteristics in electromagnetic (EM) attenuation can be generalized to other EM functional materials.
The integrated functions of efficient EM absorption ...and green shielding open the view of EM multifunctional materials.
A novel sensing mechanism based on intrinsic EM attenuation performance and EM resonance coupling effect is revealed.
It is extremely unattainable for a material to simultaneously obtain efficient electromagnetic (EM) absorption and green shielding performance, which has not been reported due to the competition between conduction loss and reflection. Herein, by tailoring the internal structure through nano-micro engineering, a NiCo
2
O
4
nanofiber with integrated EM absorbing and green shielding as well as strain sensing functions is obtained. With the improvement of charge transport capability of the nanofiber, the performance can be converted from EM absorption to shielding, or even coexist. Particularly, as the conductivity rising, the reflection loss declines from − 52.72 to − 10.5 dB, while the EM interference shielding effectiveness increases to 13.4 dB, suggesting the coexistence of the two EM functions. Furthermore, based on the high EM absorption, a strain sensor is designed through the resonance coupling of the patterned NiCo
2
O
4
structure. These strategies for tuning EM performance and constructing devices can be extended to other EM functional materials to promote the development of electromagnetic driven devices.
Graphic Abstract
A built‐in electric field in electrocatalyst can significantly accumulate higher concentration of NO3− ions near electrocatalyst surface region, thus facilitating mass transfer for efficient nitrate ...removal at ultra‐low concentration and electroreduction reaction (NO3RR). A model electrocatalyst is created by stacking CuCl (111) and rutile TiO2 (110) layers together, in which a built‐in electric field induced from the electron transfer from TiO2 to CuCl (CuCl_BEF) is successfully formed . This built‐in electric field effectively triggers interfacial accumulation of NO3− ions around the electrocatalyst. The electric field also raises the energy of key reaction intermediate *NO to lower the energy barrier of the rate determining step. A NH3 product selectivity of 98.6 %, a low NO2− production of <0.6 %, and mass‐specific ammonia production rate of 64.4 h−1 is achieved, which are all the best among studies reported at 100 mg L−1 of nitrate concentration to date.
An electrocatalyst is created by stacking CuCl (111) and rutile TiO2 (110) layers together. A built‐in electric field induced from the electron transfer from TiO2 to CuCl (CuCl_BEF) is thus formed, which triggers interfacial accumulation of NO3− ions around the electrocatalyst. A NH3 product selectivity of 98.6 %, a low NO2− production of <0.6 %, and mass‐specific ammonia production rate of 64.4 h−1 is achieved.
The COVID-19 pandemic continues to spread throughout the world with an urgent need for a safe and protective vaccine to effectuate herd protection and control the spread of SARS-CoV-2. Here, we ...report the development of a SARS-CoV-2 subunit vaccine (NVX-CoV2373) from the full-length spike (S) protein that is stable in the prefusion conformation. NVX-CoV2373 S form 27.2-nm nanoparticles that are thermostable and bind with high affinity to the human angiotensin-converting enzyme 2 (hACE2) receptor. In mice, low-dose NVX-CoV2373 with saponin-based Matrix-M adjuvant elicit high titer anti-S IgG that blocks hACE2 receptor binding, neutralize virus, and protects against SARS-CoV-2 challenge with no evidence of vaccine-associated enhanced respiratory disease. NVX-CoV2373 also elicits multifunctional CD4
and CD8
T cells, CD4
follicular helper T cells (Tfh), and antigen-specific germinal center (GC) B cells in the spleen. In baboons, low-dose levels of NVX-CoV2373 with Matrix-M was also highly immunogenic and elicited high titer anti-S antibodies and functional antibodies that block S-protein binding to hACE2 and neutralize virus infection and antigen-specific T cells. These results support the ongoing phase 1/2 clinical evaluation of the safety and immunogenicity of NVX-CoV2373 with Matrix-M (NCT04368988).
•Full-length SARS-CoV-2 prefusion spike with Matrix-M™ (NVX-CoV2373) vaccine.•Induced hACE2 receptor blocking and neutralizing antibodies in macaques.•Vaccine protected against SARS-CoV-2 replication ...in the nose and lungs.•Absence of pulmonary pathology in NVX-CoV2373 vaccinated macaques.
There is an urgent need for a safe and protective vaccine to control the global spread of SARS-CoV-2 and prevent COVID-19. Here, we report the immunogenicity and protective efficacy of a SARS-CoV-2 subunit vaccine (NVX-CoV2373) produced from the full-length SARS-CoV-2 spike (S) glycoprotein stabilized in the prefusion conformation. Cynomolgus macaques (Macaca fascicularis) immunized with NVX-CoV2373 and the saponin-based Matrix-M™ adjuvant induced anti-S antibody that was neutralizing and blocked binding to the human angiotensin-converting enzyme 2 (hACE2) receptor. Following intranasal and intratracheal challenge with SARS-CoV-2, immunized macaques were protected against upper and lower infection and pulmonary disease. These results support ongoing phase 1/2 clinical studies of the safety and immunogenicity of NVX-CoV2327 vaccine (NCT04368988).
Nitrate electrocatalytic reduction (NO3RR) for ammonia production is a promising strategy to close the N‐cycle from nitration contamination, as well as an alternative to the Haber–Bosch process with ...less energy consumption and carbon dioxide release. However, current long‐term stability of NO3RR catalysts is usually tens of hours, far from the requirements for industrialization. Here, symmetry‐broken Cusingle‐atom catalysts are designed, and the catalytic activity is retained after operation for more than 2000 h, while an average ammonia production rate of 27.84 mg h−1 cm−2 at an industrial level current density of 366 mA cm−2 is achieved, obtaining a good balance between catalytic activity and long‐term stability. Coordination symmetry breaking is achieved by embedding one Cu atom in graphene nanosheets with two N and two O atoms in the cis‐configuration, effectively lowering the coordination symmetry, rendering the active site more polar, and accumulating more NO3− near the electrocatalyst surface. Additionally, the cis‐coordination splits the Cu 3d orbitals, which generates an orbital‐symmetry‐matched π‐complex of the key intermediate *ONH and reduces the energy barrier, compared with the σ‐complex generated with other catalysts. These results reveal the critical role of coordination symmetry in single‐atom catalysts, prompting the design of more coordination‐symmetry‐broken electrocatalysts toward possible industrialization.
A coordination‐symmetry‐breaking Cusingle‐atom catalyst enables a good balance between catalytic activity and long‐term stability in nitrate electroreduction to ammonia. The catalytic activity is retained after operation for more than 2000 h, while an average ammonia production rate of 27.84 mg h−1 cm−2 at an industrial level current density of 366 mA cm−2 is achieved.
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