Boosting CO2 Hydrogenation to Formate over Edge-Sulfur Vacancies of Molybdenum Disulfide.

Synthesis of formate from hydrogenation of carbon dioxide (CO2 ) is an atom-economic reaction but is confronted with challenges in developing high-performance non-precious metal catalysts for application of the process. Herein, we report a highly durable edge-rich molybdenum disulfide (MoS2 ) catalyst for CO2 hydrogenation to formate at 200 °C, which delivers a high selectivity of over 99 % with a superior turnover frequency of 780.7 h-1 surpassing those of previously reported non-precious metal catalysts. Multiple experimental characterization techniques combined with theoretical calculations reveal that sulfur vacancies at MoS2 edges are the active sites and the selective production of formate is enabled via a completely new water-mediated hydrogenation mechanism, in which surface OH* and H* species in dynamic equilibrium with water serve as moderate hydrogenating agents for CO2 with residual O* reduced by hydrogen. This study provides a new route for developing low-cost high-performance catalysts for CO2 hydrogenation to formate.

Double defects modified carbon nitride nanosheets with enhanced photocatalytic hydrogen evolution.

Graphitic carbon nitride (g-C3N4) is an actively investigated metal-free photocatalyst for solar energy conversion. However, primary g-C3N4 usually exhibits limited utilization of visible light and fast combination of photoexcited charge carriers, resulting in low photocatalytic H2 evolution activity. Defect-modified g-C3N4 shows much enhanced photocatalytic H2 evolution activity owing to extended light absorption as well as efficient charge separation and transfer. Here, the photocatalyst simultaneously containing nitrogen vacancies and O-doping is successfully developed by using a two-step post-synthetic strategy for photocatalytic H2 evolution, resulting in a greatly-boosted H2 evolution activity (1.69 × 103 µmol g-1 h-1) compared with that of pristine g-C3N4 (1.12 × 102 µmol g-1 h-1). It is believed that the newly developed double-defect strategy may open an avenue toward obtaining molecular level comprehension of the function of a catalyst in photocatalytic H2 evolution and can be extended to the modification of other semiconductors.

Corrigendum: Tailoring mSiO2-SmCox nanoplatforms for magnetic/photothermal effect-induced hyperthermia therapy.

[This corrects the article DOI: 10.3389/fbioe.2023.1249775.].

Tailoring mSiO2-SmCox nanoplatforms for magnetic/photothermal effect-induced hyperthermia therapy.

Hyperthermia therapy is a hotspot because of its minimally invasive treatment process and strong targeting effect. Herein, a synergistic magnetic and photothermal therapeutic nanoplatform is rationally constructed. The well-dispersive mSiO2-SmCox nanoparticles (NPs) were synthesized through a one-step procedure with the regulated theoretical molar ratio of Sm/Co among 1:1, 1:2, and 1:4 for controlling the dispersion and magnetism properties of SmCox NPs in situ growth in the pore structure of mesoporous SiO2 (mSiO2), where mSiO2 with diverse porous structures and high specific surface areas serving for locating the permanent magnetic SmCox NPs. The mSiO2-SmCox (Sm/Co = 1:2) NPs with highly dispersed and uniform morphology has an average diameter of ∼73.08 nm. The photothermal conversion efficiency of mSiO2-SmCox (Sm/Co = 1:2) NPs was determined to be nearly 41%. The further in vitro and in vivo anti-tumor evaluation of mSiO2-SmCox (Sm/Co = 1:2) NPs present promising potentials for hyperthermia-induced tumor therapy due to magnetic and photothermal effects.

A new rapid screening program based on risk scores for COVID-19 patients.

We aimed at establishing a new COVID-19 risk scores, serving as a guide for rapidly screening the COVID-19 patients in order to reduce the risk of COVID-19 hospital-related transmission. As the COVID-19 disease is breaking out across the world, hospital-related transmission is one of the main factors accountable for the spread of COVID-19. For COVID-19 prevention it is urgent to establish a fast and efficient screening strategy for the COVID-19 patients. We analyzed 335 patients (including 124 patients with COVID-19). Five significant clinical attributes were selected as the components for establishing a COVID-19 risk score system, and every attribute was assigned a specific score according to their respective odds ratio values. We also compared three different screening schemes (Scheme I: temperature higher than 37.2 °C on admission, Scheme II: exposure to a source of transmission within 14 days in addition to fever, Scheme III: our new COVID-19 risk score) in terms of their respective receiver operating characteristic (ROC) curves, so as to evaluate their respective screening effectiveness. Five significant risk factors, which were exposed to a source of transmission (9 points), cluster onset (6 points), history of fever or temperature higher than 37.2 °C on admission (4 points), cough (1 point) and other atypical symptoms (1 point), were ultimately selected from many candidates to construct the new rapid COVID-19 screening program. Based on the screening scheme, the patients were quickly divided into three subgroups according to their respective COVID-19 risk scores: low risk (≤ 6 points, risk < 10%), medium risk (7-13 points) and high risk (≥ 14 points, risk > 80%). When the score of 10 points was selected as a cut-off point for differentiating the patients with COVID-19 from all of the other patients, the sensitivity was 93.6%, with a specificity of 86.3%. The area under the ROC curve (AUC) of COVID-19 risk score system was 0.96 (P = 0.000), much higher than the AUCs of Scheme I (0.56, P = 0.000) and Scheme II (0.85, P = 0.000), respectively. Our COVID-19 risk score system can help the clinicians effectively and rapidly identify and differentiate the patients with COVID-19 infections, to be mainly used in those areas where COVID-19 still exhibits epidemiological characteristics.

A Study on Relationship of Hounsfield Units Value on Non-contrast Computer Tomography and Recanalization of Intravenous Thrombolysis.

OBJECTIVE: The objective of this study is to determine whether the administration of intravenous alteplase would be beneficial or futile to patients with acute ischemic stroke caused by large vessel occlusion (LVO) before endovascular treatment (EVT) and determine the relationship between Hounsfield units (HU) in non-contrast computed tomography (NCCT) and recanalization by alteplase. METHODS: We performed a retrospective analysis of patients with acute ischemic stroke caused by LVO who received intravenous thrombolysis (IVT) or followed by EVT at our center during November 2016 and October 2020. The clinical characteristics and imaging features of patients who achieved recanalization after IVT, and those who did not, were compared. RESULTS: Forty-three eligible patients were enrolled; 12 achieved recanalization by IVT. Baseline clinical characteristics did not differ between patients of the recanalization and non-recanalization groups. HU in the NCCT were estimated and statistically significant maximum and mean values of the ipsilateral middle cerebral artery (MCA) were found between the groups (P< 0.05). The results hint that patients in the non-recanalization group have a higher rHU and δHU value of the ipsilateral MCA compared with recanalization group (P< 0.05). With regards to the receiver operator characteristic (ROC) curve, we demonstrated that a high HU value of the ipsilateral MCA could be a predictor for non-recanalization by IVT. CONCLUSION: Patients suffering LVO stroke are less likely to obtain recanalization by IVT with a high HU value of the ipsilateral MCA. It is feasible to screen patients with LVO using HU for direct EVT.

Synergistic ligand effect for the construction of titanium-oxo clusters with planar chirality and high solution stability.

A synergistic effect between dimethylglyoxime (to stabilize the Ti-O ribbon) and nonlinear dicarboxylate ligands (to bend the Ti-O ribbon) has been developed to form a series of planar chiral titanium-oxo clusters with high solution stability. The charality of the obtained clusters has been studied by X-ray structural and CD spectroscopy analysis.

Ligand-directed assembly engineering of trapezoidal {Ti5} building blocks stabilized by dimethylglyoxime.

Through ligand-directed assembly of trapezoidal {Ti5} building blocks stabilized by dimethylglyoxime, eight titanium-oxo molecular clusters with a sandwich or square planar type structures were successfully constructed, including the first success on the combination of porphyrin and titanium-oxo clusters.

Integrating the g-C3N4 Nanosheet with B-H Bonding Decorated Metal-Organic Framework for CO2 Activation and Photoreduction.

BIF-20, a zeolite-like porous boron imidazolate framework with high density of exposed B-H bonding, is combined with graphitic carbon nitride (g-C3N4) nanosheets via a facile electrostatic self-assembly approach under room temperature, forming an elegant composite BIF-20@g-C3N4 nanosheet. The as-constructed composite preferably captures CO2 and further photoreduces CO2 in high efficiency. The photogenerated excitations from the carbon nitride nanosheet can directionally migrate to B-H bonding, which effectively suppresses electron-hole pair recombination and thus greatly improves the photocatalytic ability. Compared to the g-C3N4 nanosheet, the BIF-20@g-C3N4 nanosheet composite displayed a much-enhanced photocatalytic CO2 reduction activity, which is equal to 9.7-fold enhancements in the CH4 evolution rate (15.524 µmol g-1 h-1) and 9.85-fold improvements in CO generation rate (53.869 µmol g-1 h-1). Density functional theory simulations further prove that the presence of B-H bonding in the composite is favorable for CO2 adhesion and activation in the reaction process. Thus, we believe that the implantation of functional active sites into the porous matrix provides important insights for preparation of a highly efficient photocatalyst.

Interface engineered in situ anchoring of Co9S8 nanoparticles into a multiple doped carbon matrix: highly efficient zinc-air batteries.

Interface modification is an effective and promising route for developing functional electrocatalysts. However, researchers have not created a reliable method to optimize the interfaces of components existing in electrocatalysts, although it is very crucial for the technological development of high-performance electrodes. Here, we develop a strategy aiming at the in situ anchorage of Co9S8 nanoparticles into a nitrogen (N), sulfur (S) co-implanted three-dimensional carbon matrix (Co9S8@NSCM) as a highly active and durable nonprecious metal electrocatalyst for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline medium. This strategy offers an opportunity to optimize the interface interaction and affords high activity for the ORR and OER in terms of low overpotentials and high current intensities. In addition, by confining Co9S8 nanoparticles into a N,S-doped carbon matrix, corrosion and aggregation can be effectively prevented, and thus the catalyst exhibits nearly unfading ORR catalytic performance after 100 000 s testing, a low discharge-charge voltage gap (0.81 V) and a long cycle life (up to 840 cycles) in Zn-air batteries. The present work highlights potentially powerful interface engineering for designing multi-component heterostructures with advanced performances in oxygen electrochemistry and related energy conversion.

An anionic Cd(ii) boron imidazolate framework with reversible structural transformation and biomolecular sensing properties.

An anionic Cd(ii) boron imidazolate framework (BIF-82) with gra topology has been synthesized by the targeted assembly of Cd(ii), the 1,3,5-benzenetricarboxylate ligand and the tetradentate boron imidazolate ligand, which shows reversible structural transformation, and it can encapsulate Ag nanoparticles into its structure for further sensing of cysteine.

Selectivity of CO2 via pore space partition in zeolitic boron imidazolate frameworks.

Reported here is a versatile method capable of generating pore space partition in zeolitic boron imidazolate frameworks (BIFs), which is based on the coexistence of presynthesized boron imidazolate complexes and charge balancing carboxylate ligands. Using this method, boron imidazolate complexes are used to form zeolitic nets, while the carboxylate serves to partition large channel spaces into multiple domains. The generality of this method is shown by two distinct boron imidazolate frameworks mimicking GIS (BIF-41) and ABW (BIF-42) zeotype topologies. BIF-41 shows high selectivity sorption of CO2 over N2.

Cuttlebone-derived organic matrix as a scaffold for assembly of silver nanoparticles and application of the composite films in surface-enhanced Raman scattering.

Biologically derived materials provide a rich variety of approaches toward new functional materials because of their fascinating structures and environment-friendly features, which is currently a topic of research interest. In this paper, we show that the cuttlebone-derived organic matrix (CDOM) is an excellent scaffold for the one-step synthesis and assembly of silver nanoparticles (AgNPs), which can be further used as substrate for surface-enhanced Raman scattering (SERS). Formation of AgNPs-CDOM composite was accomplished by the reaction of CDOM with AgNO(3) and NH(3).H(2)O solution at 80 degrees C without using any other stabilizer and reducing agents. UV-vis spectra and TEM were utilized to characterize the AgNPs and investigate their formation process. Results demonstrate that the size and distribution of AgNPs can be partly regulated by changing incubation time; the concentration of NH(3).H(2)O is critical to the formation rate of AgNPs. As a proof of principle, we show that the AgNPs-CDOM composite can be employed in trace analysis using SERS.

A cuttlebone-derived matrix substrate for hydrogen peroxide/glucose detection.

A simple biosensor for hydrogen peroxide (H(2)O(2)) and glucose was fabricated by incorporating gold nanoparticles (GNPs) onto a cuttlebone-derived matrix substrate (CDMS). Such a three-dimensional chamber-like structure naturally bears abundant amino groups for the direct immobilization of GNPs without a series of modifications. And preferably, the framework endows CDMS with a very high surface area for the attachment of GNPs, resulting in effective optical signal transduction and improved sensitivity of the detection system. The principle behind this biosensor is that the localized surface plasmon resonance (LSPR) of the immobilized GNPs changes with the enlargement of GNPs by H(2)O(2)-mediated chemical reduction of chloroauric acid. Using this approach, we demonstrate the proof of an optical biosensor to quantify the concentration of H(2)O(2) as well as glucose. UV-vis absorption spectra were recorded to obtain quantitative information about the H(2)O(2) or glucose concentration. The detection range of our biosensor to H(2)O(2) concentration was from 2 x 10(-6) to 1.5 x 10(-4)M, while the linear response range of glucose concentration was from 5 x 10(-6) to 5 x 10(-5)M. Inspiringly and interestingly, the growth of GNPs on CDMS gives rise to color changes, this phenomenon shows that the rapid detection by our sensor has the superiority in visual detection to a certian extent, which has been a potential application in qualitative or semiquantitative analysis for medicine and biotechnology.