Mild Construction of "Midas Touch" Metal-Organic Framework-Based Catalytic Electrodes for Highly Efficient Overall Seawater Splitting.

Mild construction of highly efficient and durable practical electrodes for overall water splitting (OWS) at industrial-grade current density is currently a significant challenge. Herein, metal-organic framework (MOF) materials are grown in situ on the surface of carbon cloth (CC) at 25 °C, and quickly "interspersed" by cobalt-boron (Co-B) via electroless plating for 30 min to obtain a highly efficient and stable CoB@MOF@CC self-supporting electrode. Owing to the large specific surface area, abundant active sites, and porous structure, the MOF-based CC modified by bamboo leaf-like ultrathin CoB has remarkable electrochemical catalysis efficiency. The CoB@MOF@CC electrode exhibits excellent performance during the hydrogen evolution reaction (η10  = 57 mV, η500  = 266 mV) and oxygen evolution reaction (η10  = 209 mV, η500  = 423 mV) in alkaline simulated seawater, and is durable for 2500 h at 500 mA cm-2 . The OWS performance is obviously enhanced by employing the prepared electrode, which only requires 1.49 V to achieve 10 mA cm-2 and is durable for over 360 h at industrial-grade current densities in alkaline high-salt, real seawater, rainwater, and urea electrolytes.

Determination of antihypertensive drugs irbesartan and doxazosin mesylate in healthcare products and urine samples using surface-enhanced Raman scattering.

In this paper, a surface-enhanced Raman scattering (SERS) strategy was constructed for the determination of antihypertensive drugs irbesartan (IRB) and doxazosin mesylate (DOX). ß-Cyclodextrin-capped silver nanoparticles (CD-AgNPs) are employed as SERS-active substrate. The introduction of ß-CD with hydrophobic cavity can capture drug molecules to form host-guest complex, making the drug molecules closer to the electromagnetic enhancement field of the AgNPs, thereby enhancing the SERS signal of drug molecules with low Raman cross-section. The vibrational modes of IRB and DOX are assigned by density functional theory calculations. The linear response from 3.0 × 10-7 to 1.0 × 10-5 mol L-1 for IRB and 3.0 × 10-7 to 2.0 × 10-5 mol L-1 for DOX and low limits of detection (LOD) 7.5 × 10-8 mol L-1 for IRB and 8.6 × 10-8 mol L-1 for DOX can be achieved. Meanwhile, this SERS approach can be applicable to determine IRB and DOX in commercial drug tablets, healthcare products, and human urine samples with recoveries of 90.8-115.7% and 90.0-113.5%, respectively, with relative standard deviation (RSD) less than 4.5%. This designed SERS strategy enables for the rapid determination of IRB and DOX in drug quality monitoring and illegal additives in healthcare products as well as clinical applications.

Mild construction of an Fe-B-O based flexible electrode toward highly efficient alkaline simulated seawater splitting.

It is essential to construct self-supporting electrodes based on earth-abundant iron borides in a mild and economical manner for grid-scale hydrogen production. Herein, a series of highly efficient, flexible, robust, and scalable Fe-B-O@FeBx modified on hydrophilic cloth (denoted as Fe-B-O@FeBx/HC, 10 cm × 10 cm) are fabricated by mild electroless plating. The overpotentials and Tafel slope values for the hydrogen and oxygen evolution reactions are 59 mV and 57.62 mV dec-1 and 181 mV and 65.44 mV dec-1, respectively; only 1.462 V is required to achieve 10 mA cm-2 during overall water splitting (OWS). Fe-B-O@FeBx/HC maintains its high catalytic activity for more than 7 days at an industrial current density (400 mA cm-2), owing to the loosened popcorn-like Fe-B-O@FeBx that is firmly loaded on a 2D-layered and mechanically robust substrate along with its fast charge and mass transfer kinetics. The chimney effect of core-shell borides@(oxyhydro)oxides enhances the OWS performance and protects the inner metal borides from further corrosion. Moreover, the flexible Fe-B-O@FeBx/HC electrode has a low cost for grid-scale hydrogen production ($2.97 kg-1). The proposed strategy lays a solid foundation for universal preparation, large-scale hydrogen production and practical applications thereof.

Rapid determination of thiram and atrazine pesticide residues in fruit and aqueous system based on surface-enhanced Raman scattering.

In this work, a rapid and sensitive strategy was developed to determine thiram (THI) and atrazine (ATZ) by surface-enhanced Raman scattering (SERS) technology. ß-cyclodextrin modified silver nanoparticles (ß-CD-AgNPs) were synthesized using ß-CD as a reducing agent and encapsulating agent under alkaline conditions and employed as SERS substrate. The existence of ß-CD can capture the molecules to form host-guest complex and fix molecular orientation in its cavity, thus ensuring the enhanced SERS signal intensity of THI and ATZ. The linear response extends from 2.56 × 10-8 to 2.56 × 10-3 mol/L for THI and 3.08 × 10-8 to 3.08 × 10-3 mol/L for ATZ, with the limits of detection (LOD) of 2.42 × 10-9 mol/L for THI and 7.26 × 10-9 mol/L for ATZ, respectively. The application of the proposed method in real samples including apple and water were investigated, and the results would help promote the application of SERS technology as a powerful analytical tool for detecting other pesticide residues. It is expected that this SERS strategy will provide great value for rapid detecting pesticide residues in food products and environmental systems.

An aptamer-based colorimetric/SERS dual-mode sensing strategy for the detection of sulfadimethoxine residues in animal-derived foods.

Residues of sulfadimethoxine (SDM) in animal-derived foods have attracted widespread public concern. Herein, we propose an aptamer-based colorimetric/SERS dual-mode sensing strategy for the determination of SDM based on hexadecyl trimethyl ammonium bromide (CTAB) induced aggregation of nanoparticles. In the absence of SDM, the SDM aptamer formed a supramolecular composite with CTAB, and the 4-mercaptopyrimidine functionalized gold nanoparticles (AuNPs@4-MPY) remained dispersed due to the lack of CTAB. Upon the addition of SDM, the SDM aptamer preferentially combined with SDM, resulting in the release of CTAB and subsequent aggregation of AuNPs@4-MPY, and the solution color changed from red to blue and presented a dynamic UV-absorbance curve based on different aggregation states. On the other hand, when, gold-silver core-shell nanoparticles (Au@AgNPs) were added additionally, the released CTAB narrowed the nanogap between AuNPs@4-MPY and Au@AgNPs, thus exhibiting enhanced SERS intensity of 4-MPY. This strategy achieved colorimetric detection of SDM with a linear range of 4.00-200.00 ng mL-1 and a detection limit of 2.41 ng mL-1, while SERS had a detection range of 1.20-120.00 ng mL-1 with a detection limit of 0.89 ng mL-1. This strategy is simple and cost-effective for the rapid detection of SDM within 20 minutes. It was further applied for the detection of SDM in spiked milk and honey samples with satisfactory recoveries. Therefore, it exhibits great potential for fast and on-site SDM detection.

Association between optic atrophy 1 polymorphisms and primary open angle glaucoma risk: Based on a meta-analysis.

BACKGROUND: Emerging evidence suggested a significant association between optic atrophy 1 (OPA1) polymorphisms and primary open angle glaucoma (POAG) risk. However, the current data are inconsistent or even contradictory. Given these, we conducted a meta-analysis to examine the precise association between OPA1 polymorphisms and POAG risk. MATERIALS AND METHODS: Online databases were retrieved, and the related studies were reviewed from inception to December 1, 2022. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to examine the statistical power of each genetic model. In addition, heterogeneity, sensitivity, cumulative analysis, and publication bias were analyzed to guarantee statistical power. RESULT: Overall, 14 studies within 11 publications (involving 2,413 POAG patients and 1,904 controls) were included and some significant association between OPA1 rs166850 C/T (T vs. C: OR = 1.24, 95%CI = 1.06-1.45, P = 0.01, I2 = 39.0%; CT vs. CC: OR = 1.37, 95%CI = 1.05-1.79, P = 0.02, I2 = 41.6%; CT + TT vs. CC: 1.37, 95%CI = 1.06-1.77, P = 0.02, I2 = 41.6%), rs10451941T/C (TC + CC vs. TT: OR = 1.79, 95%CI = 1.41-2.28, P < 0.01, I2 = 71.9%) polymorphisms and POAG susceptibility. In addition, further significant associations were also observed in the stratified analysis, especially in normal tension glaucoma groups and Caucasian descendants. CONCLUSION: The observed evidences suggest that OPA1 polymorphisms may be associate with POAG susceptibility significantly.

Risk Factors of Recurrent Stroke in Young and Middle-Aged Stroke Patients after Interventional Therapy.

Objective: To explore the risk factors of recurrent stroke in young and middle-aged stroke patients after interventional therapy. Methods: Retrospective analysis was conducted on the data of 300 young and middle-aged stroke patients treated in our hospital (February 2015-February 2017). All patients received interventional therapy. They were followed up continuously after the interventional therapy, with recurrent stroke as the only endpoint event, and those who did not have the endpoint events were followed up for 5 years. Then, the patients were divided into the occurrence group and the nonoccurrence group according to whether there was a stroke. The social demographic data and clinical examination data of all patients were collected to analyze the differences between the groups. Logistic regression analysis was performed on the factors with statistically significant differences to verify the factors affecting recurrent stroke in young and middle-aged stroke patients after interventional therapy. Results: Among the 300 patients, 69 (23.0%) had recurrent stroke and 231 (77.0%) had no recurrent stroke. The occurrence group (n = 69) had 12 cases (17.4%) of massive cerebral infarction, 18 cases (26.1%) of cerebral watershed infarction, 5 cases (7.2%) of multiple cerebral infarction, 25 cases (36.2%) of lacunar infarction, and 9 cases (13.0%) of TIA. Notable differences were observed in age, drinking history, marital status, body weight, diastolic pressure, systolic pressure, fasting blood glucose, glycosylated hemoglobin, cholesterol, and fibrinogen between the occurrence group and the nonoccurrence group (P < 0.05). The binary logistic regression analysis showed that age, drinking history, diastolic pressure, fasting blood glucose, glycosylated hemoglobin, cholesterol, and fibrinogen were the influencing factors of recurrent stroke in young and middle-aged stroke patients after interventional therapy. Conclusion: Blood glucose, blood lipid, blood pressure, age, and living habits have an impact on recurrent stroke in young and middle-aged patients after interventional therapy. Therefore, while strictly controlling blood glucose, blood lipid, and blood pressure, patients should improve their living habits and enhance the awareness of prevention after interventional therapy.

Mild construction of robust FeS-based electrode for pH-universal hydrogen evolution at industrial current density.

The development of fast and mild preparation of transition metal electrocatalysts for efficient and ultra-stable water electrolysis in wide pH range electrolytes is essential for hydrogen energy supply. Herein, ultrathin and metastable FeS nanolayer self-supported on 3D porous iron foam (IF) substrate is fabricated via one-step mild sulfurization etching for only 2 h to obtain FeS@IF electrode, which achieves efficient and long-term hydrogen evolution in alkaline simulated seawater (1.0 M KOH + 0.5 M NaCl), neutral electrolyte (1.0 M PBS) and other corrosive systems. The overpotentials are only 63 mV and 78 mV to drive 10 mA cm-2 during hydrogen evolution in 1.0 M KOH + 0.5 M NaCl and 1.0 M PBS, respectively. Additionally, the FeS@IF electrode continuously catalyzes for over 600 h at 0.2-0.4 A cm-2 in 1.0 M PBS with negligible performance loss, partly attributed to FeS nanolayer firmly etching on the surface and the formation of corrosion-resistant ultrathin nano fan-like iron sulfide oxide (FeOxSy). This uniformly-distributed morphology helps to facilitate the interfacial electron transmission between active species and substrate, expose more active sites, and provide moderate channels for the rapid liberation of gas bubbles and mass transfer. This work proposes a novel strategy for developing efficient and stable catalysts for hydrogen production in wide pH range systems.

Sulfur doped FeOx nanosheet arrays supported on nickel foam for efficient alkaline seawater splitting.

Developing economical, efficient and stable bifunctional catalysts for hydrogen production from seawater is of great significance for hydrogen utilization. Herein, sulfur doped iron oxide nanosheet arrays supported on nickel foam (FeOx-Ni3S2@NF) are prepared by a one-pot solvothermal reaction. Owing to the high intrinsic activity of FeOx-Ni3S2, the large catalytic specific surface area of nanosheet arrays and the fast charge transportation capability achieved by the self-supporting configuration, the FeOx-Ni3S2@NF electrode delivers excellent catalytic performance in alkaline simulated seawater (1 M KOH + 0.5 M NaCl). Impressively, a low overpotential of 120 mV at 50 mA cm-2 with a Tafel slope of 57 mV dec-1 for the hydrogen evolution reaction and an overpotential of 470 mV at 200 mA cm-2 with a Tafel slope of 62 mV dec-1 for the oxygen evolution reaction are achieved. More importantly, the voltage is only 1.5 V at 50 mA cm-2 for continuous overall water splitting for 100 h at 200 mA cm-2 with negligible decay in alkaline simulated seawater with almost 100% Faraday efficiency. This work provides a simple and universal strategy to prepare highly efficient bifunctional catalytic materials, promoting the development of Earth-abundant materials to catalyse seawater splitting to produce high-purity hydrogen.

The Formation Mechanism of a Self-Organized Periodic-Layered Structure at the Solid-(Cr, Fe)2B/Liquid-Al Interface.

A periodic-layered structure was observed in solid-(Cr, Fe)2B/liquid-Al diffusion couple at 750 °C. The interface morphology, the reaction products, and the potential formation mechanism of this periodic-layered structure were investigated using an electron probe microanalyzer (EPMA), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), and energy-dispersive spectroscopy (EDS). The results indicate that the reaction between (Cr, Fe)2B and liquid Al is a diffusion-controlled process. The formation of intermetallics involves both the superficial dissolution of Fe and Cr atoms and the inward diffusion of Al at the interface. The layered structure, as characterized by various experimental techniques, is alternated by a single FeAl3 layer and a (FeAl3 + Cr3AlB4) dual-phase layer. A potential mechanism describing the formation process of this periodic-layered structure was proposed based on the diffusion kinetics based on the experimental results.

Comparative Study on Microstructural Stability of Pre-annealed Electrodeposited Nanocrystalline Nickel During Pack Rolling.

Microstructural stability is an important issue for nanocrystalline materials to be practically used in many fields. The present work shows how microstructure evolves with rolling strain in pre-annealed electrodeposited nanocrystalline nickel containing an initial strong fiber texture, on the basis of X-ray diffraction line profile analysis as well as transmission electron microscopy observation. The influence of shear strain on microstructural stability of the metal/roll contact interface is compared with that of the metal/metal contact interface; the latter would be closer to deformation in plane strain compression. From the statistical microstructural information, together with experimentally observed microstructure of deformed grains after the final rolling pass, it seems fair to conclude that the microstructure of the metal/metal contact interface is more stable during pack rolling than that of the metal/roll interface.

Effect of Electric Current Pulse on Microstructure and Corrosion Resistance of Hypereutectic High Chromium Cast Iron.

The effect of electric current pulse on the microstructure and corrosion resistance of hypereutectic high chromium cast iron was explored. The morphology of carbides in solidification microstructure was observed by an optical microscope and a scanning electron microscope and the composition was determined by an electron probe micro-analyzer. The microhardness of primary carbides and corrosion resistance of samples were also compared. Under the active of electric current pulse, the microstructure of hypereutectic high chromium cast iron was homogenized and its performance improved accordingly. On treatment by electric current, the morphology of primary carbides changed from thick long rods to hexagonal blocks or granular structures. The interlayer spacing of eutectic carbide decreased from ~26.3 µm to ~17.8 µm. Size statistics showed that the average diameter of primary carbide decreased from ~220 µm to ~60 µm. As a result, microhardness increased from 1412 HV to 1511 HV. No obvious microcrack propagation was found at the microindentation sites. The average length of microcracks decreased from ~20.7 µm to ~5.7 µm. Furthermore, corrosion resistance was remarkably enhanced. The average corrosion rate decreased from 2.65 mg/cm²·h to 1.74 mg/cm²·h after pulse current treatment.

Change in Primary (Cr, Fe)7C3 Carbides Induced by Electric Current Pulse Modification of Hypereutectic High Chromium Cast Iron Melt.

In this work, an electric current pulse (ECP) of 500A was applied on a hypereutectic high chromium cast iron (HHCCI) melt before it began to solidify, and the effect of ECP on primary carbides was investigated. The characteristics of the primary carbides were analyzed by X-ray diffraction (XRD), electron probe micro-analyzer (EPMA), transmission electron microscopy (TEM), micro hardness tester, and other techniques. The results showed that ECP not only refined the primary (Cr, Fe)7C3 carbides, but also decreased the average content of Cr in the primary carbides. At the same time, the average value of micro hardness of the primary carbides increased by about 84 Kgf/mm², which contradicts existing knowledge that hardness increases with an increase in Cr content. XRD analysis showed that the crystal structure of the primary carbides did not change. The results of EPMA indicated that the Cr/Fe ratio gradually decreased from the center to the edges of the carbide particles. Further investigation revealed that the uneven distribution of elements caused by ECP led to an increase in defects (including twins, antiphase boundaries, and dislocations). This increase in defect density is the main reason for the increase in micro hardness instead of the expected decrease. The mechanism of the change in primary carbides was analyzed in detail in this paper, which has provided a new method for the refinement of primary carbides and for improving the properties of primary carbides.

Characterization of Polyphenols from Lycium ruthenicum Fruit by UPLC-Q-TOF/MS(E) and Their Antioxidant Activity in Caco-2 Cells.

The fruit of Lycium ruthenicum Murr. (LRF) has long been used in folk medicine. Nevertheless, detailed information related to its polyphenol compositions remains scarce. In this study, we confirmed that the total phenolic and anthocyanin contents of LRF fruit extracts (LRFEs) were 4906.5 ± 60.6 mg of gallic acid equivalents/100 g DW and 787.6 ± 34.1 mg of cyanindin-3-glucoside equivalents/100 g DW, respectively. A characterization of LRFEs was performed by ultrahigh performance liquid chromatography/quadrupole time-of-flight mass spectrometry using an MS(E) data acquisition. A total of 26 polyphenols were tentatively identified, of which 19 represent the first reports of these polyphenols in LRFEs. Furthermore, the cellular antioxidant array showed that LRFEs could protect Caco-2 cells against H2O2-induced oxidative damage based on microscopic fluorometric imaging.