Experimental study on the dynamic mechanical response of a blue light-stimulated acrylate side chain liquid crystal elastomer.

This study demonstrates a breakdown analysis of the dynamics of a liquid crystal elastomer (LCE) including quality check, geometric measurement, thermal characterization, and comparison of heat- and light-induced contractions. A blue light-responsive acrylate side chain LCE with 1% azobenzene dye was characterized. From a classical viewpoint, photo-thermal contraction is considered a dominating effect, while direct photo-mechanical deformation can be neglected due to a low dye percentage. However, the findings of this research suggest that a low percentage of azobenzene dye does not necessarily lead to heat-dominating dynamics of LCE. This phenomenon has not yet been quantitatively studied before. The approach reported in this Letter can potentially be used to extract the data to improve the dynamics models of light-driven LCEs.

RAGE Is a Receptor for SARS-CoV-2 N Protein and Mediates N Protein-induced Acute Lung Injury.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (N-protein) increases early in body fluids during infection and has recently been identified as a direct inducer for lung injury. However, the signal mechanism of N-protein in the lung inflammatory response remains poorly understood. The goal of this study was to determine whether RAGE (receptor for advanced glycation endproducts) participated in N-protein-induced acute lung injury. The binding between N-protein and RAGE was examined via assays for protein-protein interaction. To determine the signaling mechanism in vitro, cells were treated with recombinant N-protein and assayed for the activation of the RAGE/MAPK (mitogen-activated protein kinase)/NF-ĸB pathway. RAGE deficiency mice and antagonist were used to study N-protein-induced acute lung injury in vivo. Binding between N-protein and RAGE was confirmed via flow cytometry-based binding assay, surface plasmon resonance, and ELISA. Pull-down and coimmunoprecipitation assays revealed that N-protein bound RAGE via both N-terminal and C-terminal domains. In vitro, N-protein activated the RAGE-ERK1/2-NF-ĸB signaling pathway and induced a proinflammatory response. RAGE deficiency subdued N-protein-induced proinflammatory signaling and response. In vivo, RAGE was upregulated in the BAL and lung tissue after recombinant N-protein insult. RAGE deficiency and small molecule antagonist partially protected mice from N-protein-induced acute lung injury. Our study demonstrated that RAGE is a receptor for N-protein. RAGE is partially responsible for N-protein-induced acute lung injury and has the potential to become a therapeutic target for treating coronavirus disease.

Risk factors of postoperative neurodevelopmental abnormalities in neonates with critical congenital heart disease. / å±é‡å ˆå¤©æ€§å¿ƒè„ç— æ–°ç”Ÿå„¿æœ¯åŽæ–°å‘ç¥žç»å‘è‚²å¼‚å¸¸çš„å±é™©å› ç´ .

OBJECTIVES: To investigate the risk factors of postoperative neuro-developmental abnormalities in neonates with critical congenital heart disease (CCHD). METHODS: Clinical data of 50 neonates with CCHD admitted in the Cardiac Intensive Care Unit, The Children's Hospital, Zhejiang University School of Medicine from November 2020 to December 2021 were retrospectively analyzed. Neurological assessment was performed with cranial ultrasonography, CT/MRI, video electroencephalogram and clinical symptoms before and after surgical treatment for all patients, and neurodevelopmental abnormalities were documented. Binary logistic stepwise regression was used to analyze risk factors of postoperative new-onset neurodysplasia in children with CCHD, and the predictive value of the risk factors on postoperative neurodevelopmental abnormalities were evaluated using the receiver operating characteristic (ROC) curve. RESULTS: Neurodevelopmental abnormalities were detected in 22 cases (44.0%) and not detected in 28 cases (56.0%) before surgery. There were no significant differences in gender, birth weight, age at admission, gestational age, preoperative SpO2 level, prematurity, cyanotic congenital heart disease, and ventilator support between the two groups (all P>0.05). After surgery, there were 22 cases (44.0%) with new-onset neurological abnormalities and 28 cases (56.0%) without new-onset abnormalities. Multivariate logistic regression analysis showed that postoperative 24 h peak lactic acid (OR=1.537, 95%CI: 1.170-2.018, P<0.01) and postoperative length of ICU stay (OR=1.172, 95%CI:1.031-1.333, P<0.05) were independent risk factors for postoperative new-onset neurodevelopmental abnormalities. The area under ROC curve (AUC) of the postoperative 24 h peak lactic acid for predicting the new-onset neurological abnormalities after operation was 0.829, with cut-off value of 4.95 mmol/L. The diagnostic sensitivity and specificity were 90.0% and 64.3%, respectively. The AUC of postoperative length of ICU stay for predicting the new-onset neurological abnormalities after operation was 0.712, with cut-off value of 18.0 d. The diagnostic sensitivity and specificity were 50.0% and 96.4%, respectively. The AUC of the combination of the two indicators was 0.917, the diagnostic sensitivity and specificity were 95.5% and 64.3%, respectively. CONCLUSIONS: The incidence of neurodysplasia in neonatal CCHD is high, and new neurological abnormalities may occur after surgery. The postoperative 24 h peak lactic acid and postoperative length of ICU stay are risk factors for new-onset neurodysplasia after surgery. The combination of the two indicators has good predictive value for neurodevelopmental outcomes after surgery in CCHD infants.

Semiconductor Gas Sensor for Triethylamine Detection.

With the demanding detection of unique toxic gas, semiconductor gas sensors have attracted tremendous attention due to their intriguing features, such as, high sensitivity, online detection, portability, ease of use, and low cost. Triethylamine, a typical gas of volatile organic compounds, is an important raw material for industrial development, but it is also a hazard to human health. This review presents a concise compilation of the advances in triethylamine detection based on chemiresistive sensors. Specifically, the testing system and sensing parameters are described in detail. Besides, the sensing mechanism with characterizing tactics is analyzed. The research status based on various chemiresistive sensors is also surveyed. Finally, the conclusion and challenges, as well as some perspectives toward this area, are presented.

Highly Strained Bi-MOF on Bismuth Oxyhalide Support with Tailored Intermediate Adsorption/Desorption Capability for Robust CO2 Photoreduction.

Herein, using as-designed surface-mounted Bismuth-based metal-organic framework (Bi-MOF) on two-dimensional BiOBr support, as an operable platform for site-specific strain engineering to tailor the intermediate adsorption/desorption capability in CO2 photocatalytic conversion is proposed. Giant compressive strain up to 7.85 % is successfully induced on the surface-mounted Bi-MOF revealed by HRTEM images and geometric phase analysis as well as in situ Raman characterization, which largely downshifts the p band center of Bi nodes and intensifies their unsaturated state. In-depth explorations are put onto p-p (Bi 6p and CO2 /CO 2p) orbital hybridization. Taking the adsorption process as an example, the 1π and 7σ frontier molecule orbitals of CO2 2p for both the strain-free and strained models shift downwards the Fermi level, indicative of fast adsorption of CO2 . Meanwhile, strain engineering further induces new non-degenerate orbital overlapping near 1π and intensified overlapping of 7σ orbitals, stimulating the fast activation of absorbed CO2 molecules.

Carbon-Graphitic Carbon Nitride Hybrids for Heterogeneous Photocatalysis.

Polymeric graphitic carbon nitride (g-C3 N4 ) and various carbon materials have experienced a renaissance as viable alternates in photocatalysis due to their captivating metal-free features, favorable photoelectric properties, and economic adaptabilities. Although numerous efforts have focused on the integration of both materials with optimized photocatalytic performance in recent years, the direct parameters for this emerging enhancement are not fully summarized yet. Fully understanding the synergistic effects between g-C3 N4 and carbon materials on photocatalytic action is vital to further development of metal-free semiconductors in future studies. Here, recent advances of carbon/g-C3 N4 hybrids on various photocatalytic applications are reviewed. The dominant governing factors by inducing carbon into g-C3 N4 photocatalysts with involving photocatalytic mechanism are highlighted. Five typical carbon-induced enhancement effects are mainly discussed here, i.e., local electric modification, band structure tailoring, multiple charge carrier activation, chemical group functionalization, and abundant surface-modified engineering. Photocatalytic performance of carbon-induced g-C3 N4 photocatalysts for addressing directly both the renewable energy storage and environmental remediation is also summarized. Finally, perspectives and ongoing challenges encountered in the development of metal-free carbon-induced g-C3 N4 photocatalysts are presented.

Plasmonic semiconductor photocatalyst: Non-stoichiometric tungsten oxide.

Semiconductor photocatalysis has attracted increasing attention due to its potential application in solving the problems related to energy crisis and environmental pollution. As a typical plasmonic semiconductor, non-stoichiometric tungsten oxide (WO3-X) has invoked significant interest for its unique property and excellent photocatalytic performance. In this review, we briefly introduce the fundamental properties of the WO3-x, and then summarize the synthesis methods such as solvothermal reaction, solid phase reduction and exfoliation treatment, together with the modification strategies such as doping and constructing homo-/hetero-junctions. Additionally, we emphasize the practical applications of WO3-x in hydrogen evolution, nitrogen fixation, carbon dioxide reduction, and pollutant degradation. Finally, comprehensive conclusions and perspectives on the fabrication of WO3-x photocatalyst leading to satisfactory performance are given as well.

Graphdiyne: A Brilliant Hole Accumulator for Stable and Efficient Planar Perovskite Solar Cells.

Traditional carbon materials have demonstrated immense potential in perovskite solar cells (PSCs) owing to their superior electrical properties and environmental stability. Graphdiyne (GDY), as an emerging carbon allotrope, features uniformly distributed pores, endless design flexibility, and unique electronic character compared with traditional carbon materials. Herein, graphdiyne is introduced into the upper part of the perovskite (CH3 NH3 PbI3 ) layer by utilizing a GDY-containing antisolvent during the one-step synthesis of perovskite. Intriguingly, GDY plays an essential role in hole accumulation and transportation because of its higher Fermi level than perovskite. As a result, the automatic separation of photogenerated carriers inside the perovskite film is achieved. Furthermore, the Schottky barrier formed on the interface between perovskite and GDY guarantees the unidirectional hole transport from perovskite to GDY, thereby benefiting further extraction to the hole transport layer. Consequently, GDY-modified perovskite-based planar PSCs exhibit a boosted Jsc of 24.21 mA cm-2 and up to 19.6% power conversion efficiency owing to the increased efficient light utilization and charge extraction. The device with GDY modification exhibits less than 10% shrinkage after a month in ambience. Overall, this work demonstrates an easy method for the utilization of GDY to boost the charge extraction and environmental stability in PSCs.

Single Ni Atoms Anchored on Porous Few-Layer g-C3 N4 for Photocatalytic CO2 Reduction: The Role of Edge Confinement.

It is greatly intriguing yet remains challenging to construct single-atomic photocatalysts with stable surface free energy, favorable for well-defined atomic coordination and photocatalytic carrier mobility during the photoredox process. Herein, an unsaturated edge confinement strategy is defined by coordinating single-atomic-site Ni on the bottom-up synthesized porous few-layer g-C3 N4 (namely, Ni5 -CN) via a self-limiting method. This Ni5 -CN system with a few isolated Ni clusters distributed on the edge of g-C3 N4 is beneficial to immobilize the nonedged single-atomic-site Ni species, thus achieving a high single-atomic active site density. Remarkably, the Ni5 -CN system exhibits comparably high photocatalytic activity for CO2 reduction, giving the CO generation rate of 8.6 µmol g-1 h-1 under visible-light illumination, which is 7.8 times that of pure porous few-layer g-C3 N4 (namely, CN, 1.1 µmol g-1 h-1 ). X-ray absorption spectrometric analysis unveils that the cationic coordination environment of single-atomic-site Ni center, which is formed by Ni-N doping-intercalation the first coordination shell, motivates the superiority in synergistic N-Ni-N connection and interfacial carrier transfer. The photocatalytic mechanistic prediction confirms that the introduced unsaturated Ni-N coordination favorably binds with CO2 , and enhances the rate-determining step of intermediates for CO generation.

Fe1 /TiO2 Hollow Microspheres: Fe and Ti Dual Active Sites Boosting the Photocatalytic Oxidation of NO.

Recently, single-atom catalysts have aroused extensive attention in fields of clean energy and environmental protection due to their unique activity and efficient utilization of the active atoms. It is of great importance but still remains a great challenge to unveil the effect of single atoms on precise catalysis. Herein, it is reported that doping TiO2 hollow microspheres (TiO2 -HMSs) with single atomic Fe can boost the photoreactivity of TiO2 -HMSs towards NO oxidation due to the synergistic effects of atomically dispersed Fe and bonded Ti atom which act as dual active sites. The atomically dispersed Fe atoms occupy the subsurface Ti vacancies, and the interaction between Ti 3d and Fe 3d orbitals result in the formation of FeTi bond. Single atomic Fe modulates the electronic structure of the bonded Ti atoms by electron transfer, which facilitates the adsorption and activation of NO and O2 at Fe and bonded Ti sites, respectively. In addition, the introduction of single atomic Fe sharply suppresses the production of toxic NO2 byproduct. The synergistic effects of the dual active sites then cause a drastic promotion in photocatalytic oxidation of NO.

Dynamic prediction of optical and chromatic performances for a light-emitting diode array based on a thermal-electrical-spectral model.

Light-emitting diode (LED) arrays have attracted increased attention in the area of high power intelligent automotive headlamps because of their superiority in disposing of the power limit of an individual LED package and controllably luminous intensity and illumination pattern. The optical and chromatic performances of an LED array do not equal to the sum of individual LED packages' performances, as the thermal interactions between individual LED packages can't be ignored in the actual application. This paper presents a thermal-electrical-spectral (TES) model to dynamically predict the optical and chromatic performances of the LED array. The thermal-electrical (TE) model considering the thermal coupling effect in the LED array is firstly proposed to predict the case temperature of each individual LED package, and the Spectral power distributions (SPDs) of individual LED package is then decomposed by the extended Asym2sig model to extract the spectral characteristic parameters. Finally, the experimental measurements of the designed LED arrays operated under usage conditions are used to verify the TES model. Some validation case studies show that the prediction accuracy of the proposed TES model, which is expressed as a quadratic polynomial function of current and case temperature, can be achieved higher than 95%. Therefore, it can be concluded that this TES model offers a convenient method with high accuracy to dynamically predict the optical and chromatic performances of LED arrays at real usages.

Trace-Level Fluorination of Mesoporous TiO2 Improves Photocatalytic and Pb(II) Adsorbent Performances.

Fluorination is an effective way of tuning the physicochemical property and activity of TiO2 nanocrystallites, which usually requires a considerable amount of hydrofluoric acid (or NH4F) for a typical F/Ti molar ratio, RF, of 0.5-69.0 during synthesis. This has consequential environmental issues due to the high toxicity and hazard of the reactants. In the present work, an environmentally benign fluorination approach is demonstrated that uses only a trace amount of sodium fluoride with an RF of 10-6 during synthesis. While it maintained the desirable high surface area (102.4 m2/g), the trace-level fluorination enabled significant enhancements on photocatalytic activities (e.g., a 56% increase on hydrogen evolution rate) and heavy metal Pb(II) removal (31%) of the mesoporous TiO2. This can be attributed to enriched Ti3+ and localized spatial charge separation due to fluorination as proved by X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance spectroscopy (EPR), and density functional theory (DFT) analyses.

Stereodivergent Protein Engineering of a Lipase To Access All Possible Stereoisomers of Chiral Esters with Two Stereocenters.

Enzymatic stereodivergent synthesis to access all possible product stereoisomers bearing multiple stereocenters is relatively undeveloped, although enzymes are being increasingly used in both academic and industrial areas. When two stereocenters and thus four stereoisomeric products are involved, obtaining stereodivergent enzyme mutants for individually accessing all four stereoisomers would be ideal. Although significant success has been achieved in directed evolution of enzymes in general, stereodivergent engineering of one enzyme into four highly stereocomplementary variants for obtaining the full complement of stereoisomers bearing multiple stereocenters remains a challenge. Using Candida antarctica lipase B (CALB) as a model, we report the protein engineering of this enzyme into four highly stereocomplementary variants needed for obtaining all four stereoisomers in transesterification reactions between racemic acids and racemic alcohols in organic solvents. By generating and screening less than 25 variants of each isomer, we achieved >90% selectivity for all of the four possible stereoisomers in the model reaction. This difficult feat was accomplished by developing a strategy dubbed "focused rational iterative site-specific mutagenesis" (FRISM) at sites lining the enzyme's binding pocket. The accumulation of single mutations by iterative site-specific mutagenesis using a restricted set of rationally chosen amino acids allows the formation of ultrasmall mutant libraries requiring minimal screening for stereoselectivity. The crystal structure of all stereodivergent CALB variants, flanked by MD simulations, uncovered the source of selectivity.

Unraveling Photoexcited Charge Transfer Pathway and Process of CdS/Graphene Nanoribbon Composites toward Visible-Light Photocatalytic Hydrogen Evolution.

Converting solar energy into chemical fuels is increasingly receiving a great deal of attention. In this work, CdS nanoparticles (NPs) are solvothermally anchored onto graphene nanoribbons (GNRs) that are longitudinally unzipped from multiwalled carbon nanotubes. The as-synthesized CdS/GNR nanocomposites with recyclability present GNR content-dependent activity in visible-light-driven hydrogen evolution from water splitting. In a range of 1-10 wt% GNRs, the CdS/GNR composites with 2 wt% GNRs achieves the greatest hydrogen evolution rate of 1.89 mmol h-1 g-1 . The corresponding apparent quantum efficiency is 19.3%, which is ≈3.7 times higher than that of pristine CdS NPs. To elucidate the underlying photocatalytic mechanism, a systematic characterization, including in situ irradiated X-ray photoelectron spectroscopy and Kelvin probe measurements, is performed. In particular, the interfacial charge transfer pathway and process from CdS NPs to GNRs is revealed. This work may open avenues to fabricate GNR-based nanocomposites for solar-to-chemical energy conversion and beyond.

Exploiting Cofactor Versatility to Convert a FAD-Dependent Baeyer-Villiger Monooxygenase into a Ketoreductase.

Cyclohexanone monooxygenases (CHMOs) show very high catalytic specificity for natural Baeyer-Villiger (BV) reactions and promiscuous reduction reactions have not been reported to date. Wild-type CHMO from Acinetobacter sp. NCIMB 9871 was found to possess an innate, promiscuous ability to reduce an aromatic α-keto ester, but with poor yield and stereoselectivity. Structure-guided, site-directed mutagenesis drastically improved the catalytic carbonyl-reduction activity (yield up to 99 %) and stereoselectivity (ee up to 99 %), thereby converting this CHMO into a ketoreductase, which can reduce a range of differently substituted aromatic α-keto esters. The improved, promiscuous reduction activity of the mutant enzyme in comparison to the wild-type enzyme results from a decrease in the distance between the carbonyl moiety of the substrate and the hydrogen atom on N5 of the reduced flavin adenine dinucleotide (FAD) cofactor, as confirmed using docking and molecular dynamics simulations.

Light-Driven Kinetic Resolution of α-Functionalized Carboxylic Acids Enabled by an Engineered Fatty Acid Photodecarboxylase.

Chiral α-functionalized carboxylic acids are valuable precursors for a variety of medicines and natural products. Herein, we described an engineered fatty acid photodecarboxylase (CvFAP)-catalyzed kinetic resolution of α-amino acids and α-hydroxy acids, which provides the unreacted R-configured substrates with high yields and excellent stereoselectivity (ee up to 99 %). This efficient light-driven process requires neither NADPH recycling nor prior preparation of esters, which were required in previous biocatalytic approaches. The structure-guided engineering strategy is based on the scanning of large amino acids at hotspots to narrow the substrate binding tunnel. To the best of our knowledge, this is the first example of asymmetric catalysis by an engineered CvFAP.

Strong temperature-dependent crystallization, phase transition, optical and electrical characteristics of p-type CuAlO2 thin films.

We report here a reliable and reproducible single-step (without post-annealing) fabrication of phase-pure p-type rhombohedral CuAlO2 (r-CuAlO2) thin films by reactive magnetron sputtering. The dependence of crystallinity and phase compositions of the films on the growth temperature was investigated, revealing that highly-crystallized r-CuAlO2 thin films could be in situ grown in a narrow temperature window of ∼940 °C. Optical and electrical property studies demonstrate that (i) the films are transparent in the visible light region, and the bandgaps of the films increased to ∼3.86 eV with the improvement of crystallinity; (ii) the conductance increased by four orders of magnitude as the film was evolved from the amorphous-like to crystalline structure. The predominant role of crystallinity in determining CuAlO2 film properties was demonstrated to be due to the heavy anisotropic characteristics of the O 2p-Cu 3d hybridized valence orbitals.

Polymorphism -433 C>T of the Osteopontin gene is associated with the susceptibility to develop gliomas and their prognosis in a Chinese cohort.

AIM: To investigate role of the Osteopontin (OPN) genetic polymorphisms in the susceptibility to gliomas and their prognosis. METHODS: A total of 248 Chinese glioma patients and 281 age and sex matched healthy controls were recruited. The genetic polymorphisms at three loci, namely, -156 GG>G, -443 C>T and -66T>G, were determined. The log-rank test and Kaplan- Meier analysis were introduced to assess the effect of OPN gene polymorphisms on patient survival. RESULTS: We found that the genotype frequencies of OPN -443 C>T polymorphism were significantly different between glioma patients and controls. Multivariable analyses showed a higher risk for gliomas in -443 CC genotype carriers compared to -443TT carriers (P<0.001). In addition, we also found the OPN -443 C>T polymorphism was closely related to the gliomas' tumor grade. The -443 C>T polymorphism also affected the tumor OPN expression level, but not the serum OPN level. More importantly, the -443 C>T polymorphism was significantly associated with the prognosis of these patients regardless of their treatment status. The patients with -443CC genotype had a poorer prognosis than those with -443TT and -443CT genotypes. In contrast, the -156 G>GG and -66T>G polymorphisms were not associated with risk, clinical characteristics, or prognosis of gliomas. CONCLUSION: This study suggests that the -443C>T gene polymorphisms may be used as a molecular marker for glioma occurrence and clinical outcome in glioma patients.

Microstructure changes and miRNA-mRNA network in a developmental dysplasia of the hip rat model.

MicroRNAs (miRNAs) interact with mRNAs in various pathophysiological processes. In developmental dysplasia of the hip (DDH), the miRNA-mRNA pairs affecting acetabular cartilage (AC) development remain unknown. We investigated dynamic microstructure changes and mRNA and miRNA expression profiles in the AC proliferative zone in a DDH rat model. Abnormal chondrocyte proliferation was observed, and several differentially expressed mRNAs and miRNAs were identified. Downregulated mRNAs and target genes of upregulated miRNAs were primarily enriched in bone and cartilage development. Six hub genes were identified using the predicted miRNA-mRNA interaction network and gene expression pattern analysis. The expression levels of these hub genes and paired miRNAs aligned with our predictions, and most of the pairs were significantly negatively correlated. Excessive chondrocyte proliferation in the AC proliferative zone can delay AC ossification, which might be crucial to DDH development. Specific miRNA-mRNA interaction pairs may serve as diagnostic biomarkers and therapeutic targets.

Advances in zeolitic-imidazolate-framework-based catalysts for photo-/electrocatalytic water splitting, CO2 reduction and N2 reduction applications.

Harnessing electrical or solar energy for the renewable production of value-added fuels and chemicals through catalytic processes (such as photocatalysis and electrocatalysis) is promising to achieve the goal of carbon neutrality. Owing to the large number of highly accessible active sites, highly porous structure, and charge separation/transfer ability, as well as excellent stability against chemical and electrochemical corrosion, zeolite imidazolate framework (ZIF)-based catalysts have attracted significant attention. Strategic construction of heterojunctions, and alteration of the metal node and the organic ligand of the ZIFs effectively regulate the binding energy of intermediates and the reaction energy barriers that allow tunable catalytic activity and selectivity of a product during reaction. Focusing on the currently existing critical issues of insufficient kinetics for electron transport and selective generation of ideal products, this review starts from the characteristics and physiochemical advantages of ZIFs in catalytic applications, then introduces promising regulatory approaches for advancing the kinetic process in emerging CO2 reduction, water splitting and N2 reduction applications, before proposing perspective modification directions.