Modulating CO2 Electrocatalytic Conversion to the Organics Pathway by the Catalytic Site Dimension.

Electrochemical reduction of carbon dioxide to organic chemicals provides a value-added route for mitigating greenhouse gas emissions. We report a family of carbon-supported Sn electrocatalysts with the tin size varying from single atom, ultrasmall clusters to nanocrystallites. High single-product Faradaic efficiency (FE) and low onset potential of CO2 conversion to acetate (FE = 90% @ -0.6 V), ethanol (FE = 92% @ -0.4 V), and formate (FE = 91% @ -0.6 V) were achieved over the catalysts of different active site dimensions. The CO2 conversion mechanism behind these highly selective, size-modulated p-block element catalysts was elucidated by structural characterization and computational modeling, together with kinetic isotope effect investigation.

Hydrogel Rivet with Unidirectional Shape Morphing for Flexible Mechanical Assembly.

Integrating diverse materials and functions into highly additive produce has piqued global interest due to the increasing demands of intelligent soft robotics. Nevertheless, existing assembly techniques, especially supramolecular assembly which heavily rely on precise chemical design and specific recognition, may prove inadequate when confronted with diverse external demands. Inspired by the traditional mechanical assembly, rivet connection, herein, a thermo-responsive hydrogel with unidirectional shape-morphing is fabricated and a stable mechanical assembly is constructed by emulating the rivet connection mechanism. This system employed poly(acrylamide-co-acrylic acid) [P(AAm-co-AAc)] to induce continuous swelling and hexylamine-modified polyvinyl alcohol (PVA-C6) as a molecular switch to control the swelling process. The hydrogel rivet, initially threaded through pre-fabricated hollows in two components. Subsequently, upon the disassociation of alkane chains the molecular switch would activate, inducing swelling and stable mechanical assembly via anchor structures. Moreover, to enhance the assembly strength, knots are introduced to enhance assembly strength, guiding localized stress release for programmed deformations. Additionally, the system can be remotely controlled using near-infrared light (NIR) by incorporating photo-thermal nanoparticles. This work presents a universal and efficient strategy for constructing stable mechanical assemblies without compromising overall softness, offering significant potential for the fabrication of integrated soft robots.

Associations of coal mine dust exposure with arterial stiffness and atherosclerotic cardiovascular disease risk in chinese coal miners.

OBJECTIVE: Whether coal mine dust exposure increases cardiovascular diseases (CVDs) risk was rarely explored. Our objective was to examine the association between coal mine dust exposure and cardiovascular risk. METHODS: We estimated cumulative coal mine dust exposure (CDE) for 1327 coal miners by combining data on workplace dust concentrations and work history. We used brachial-ankle pulse wave velocity (baPWV, a representative indicator of arterial stiffness) and ten-year atherosclerotic cardiovascular disease (ASCVD) risk to assess potential CVD risk, exploring their associations with CDE. RESULTS: Positive dose-response relationships of CDE with baPWV and ten-year ASCVD risk were observed after adjusting for covariates. Specifically, each 1 standard deviation (SD) increase in CDE was related to a 0.27 m/s (95% CI: 0.21, 0.34) increase in baPWV and a 1.29 (95% CI: 1.14, 1.46) elevation in OR (odds ratio) of risk of abnormal baPWV. Moreover, each 1 SD increase in CDE was associated with a 0.74% (95% CI: 0.63%, 0.85%) increase in scores of ten-year ASCVD and a 1.91 (95% CI: 1.62, 2.26) increase in OR of risk of ten-year ASCVD. When compared with groups unexposed to coal mine dust, significant increase in the risk of arterial stiffness and ten-year ASCVD in the highest CDE groups were detected. CONCLUSION: The study suggested that cumulative exposure to coal mine dust was associated with elevated arterial stiffness and ten-year ASCVD risk in a dose-response manner. These findings contribute valuable insights for cardiovascular risk associated with coal mine dust.

Heck Migratory Insertion Catalyzed by a Single Pt Atom Site.

Single-atom catalysts (SACs) have generated excitement for their potential to downsize metal particles to the atomic limit with engineerable local environments and improved catalytic reactivities and selectivities. However, successes have been limited to small-molecule transformations with little progress toward targeting complex-building reactions, such as metal-catalyzed cross-coupling. Using a supercritical carbon-dioxide-assisted protocol, we report a heterogeneous single-atom Pt-catalyzed Heck reaction, which provides the first C-C bond-forming migratory insertion on SACs. Our quantum mechanical computations establish the reaction mechanism to involve a novel C-rich coordination site (i.e., PtC4) that demonstrates an unexpected base effect. Notably, the base was found to transiently modulate the coordination environment to allow migratory insertion into an M-C species, a process with a high steric impediment with no previous example on SACs. The studies showcase how SACs can introduce coordination structures that have remained underexplored in catalyst design. These findings offer immense potential for transferring the vast and highly versatile reaction manifold of migratory-insertion-based bond-forming protocols to heterogeneous SACs.

Valence Engineering Enhancing NH4 + Storage Capacity of Manganese Oxides.

Ammonium ions (NH4 + ), as non-metallic charge carriers, are attracting attention in aqueous batteries due to its low molar mass, element sufficiency, and non-toxicity. However, the host materials for NH4 + storage are still limited. Herein, an oxygen defects-rich manganese oxide (MnO2-x ) for NH4 + storage are reported. The oxygen defects can endow the MnO2-x sample with improved electric conductivity and low interface activation energy. The electrochemical reaction mechanism is also verified by using ex situ X-ray photoelectron spectroscopy (XPS) and fourier transform infrared spectroscopy (FT-IR), demonstrating the insertion and extraction of NH4 + in the MnO2-x by formation/breaking of a hydrogen bond. As a result, MnO2-x delivers a high capacity of 109.9 mAh g-1 at the current density of 0.5 A g-1 and retention of 24 mAh g-1 after 1000 cycles at the current density of 4 A g-1 , outperforming the pristine MnO2 sample.

Tendency Regulation of Competing Reactions Toward Highly Reversible Tin Anode for Aqueous Alkaline Batteries.

Investigating dendrite-free stripping/plating anodes is highly significant for advancing the practical application of aqueous alkaline batteries. Sn has been identified as a promising candidate for anode material, but its deposition/dissolution efficiency is hindered by the strong electrostatic repulsion between Sn(OH)3 - and the substrate. Herein, this work constructs a nondense copper layer which serves as stannophile and hydrogen evolution inhibitor to adjust the tendency of competing reactions on Sn foil surface, thus achieving a highly reversible Sn anode. The interactions between the deposited Sn and the substrates are also strengthened to prevent shedding. Notably, the ratio of Sn redox reaction is significantly boosted from ≈20% to ≈100%, which results in outstanding cycling stability over 560 h at 10 mA cm-2 . A Sn//Ni(OH)2 battery device is also demonstrated with capacities from 0.94 to 22.4 mA h cm-2 and maximum stability of 1800 cycles.

Anion Effects on Spin Crossover Systems: From Supramolecular Chemistry to Magnetism.

The field of anion supramolecular chemistry has received more and more attention in recent years. Anions with diverse types and geometries have been widely used for the synthesis of ionic spin crossover (SCO) complexes. This review is devoted to anion effects on the molecular, supramolecular structures and magnetic properties of discrete SCO compounds. Firstly, typical anions used in the synthesis of these compounds are briefly summarized according to their various geometries. This is followed by a collection of representative examples of anion-based SCO compounds, whose SCO properties are analyzed in terms of supramolecular interactions, geometry and charge of anions. In the third part, anion effects on SCO complexes of different kinds of metal centers and ligands are outlined and finally remarks on the synthesis new type of ionic SCO complexes in the future are described.

Feedback Interaction Between Apelin and Endoplasmic Reticulum Stress in the Rat Myocardium.

ABSTRACT: Apelin is an endogenous active peptide, playing a crucial role in regulating cardiovascular homeostasis. This study aimed to investigate the interaction between apelin and endoplasmic reticulum stress (ERS). Tunicamycin (Tm) and dithiothreitol (DTT) were used to induce ERS in the ex vivo cultured myocardium of rats. Myocardial injury was determined by the activities of lactate dehydrogenase and creatine kinase-MB in the culture medium. The protein levels of an ERS-associated molecule, apelin, and its receptor angiotensin domain type 1 receptor-associated proteins (APJ) in the myocardium were determined by western blot analysis. The level of apelin in the culture medium was determined by enzyme immunoassay. Administration of Tm and DTT triggered ERS activation and myocardial injury, and led to a decrease in protein levels of apelin and APJ, in a dose-dependent manner. Integrated stress response inhibitor, an inhibitor of eukaryotic initiation factor 2α phosphorylation that is commonly used to prevent activation of protein kinase R-like ER kinase cascades, blocked ERS-induced myocardial injury and reduction of apelin and APJ levels. The ameliorative effect of integrated stress response inhibitor was partially inhibited by [Ala]-apelin-13, an antagonist of APJ. Furthermore, apelin treatment inhibited activation of the 3 branches of ERS induced by Tm and DTT in a dose-dependent manner, thereby preventing Tm-induced or DTT-induced myocardial injury. The negative feedback regulation between ERS activation and apelin/APJ suppression might play a critical role in myocardial injury. Restoration of apelin/APJ signaling provides a potential target for the treatment and prevention of ERS-associated tissue injury and diseases.

Quantifying the policy-driven large scale vegetation restoration effects on evapotranspiration over drylands in China.

Evapotranspiration (ET) is a key variable in the water cycle and reflects the ecosystem's feedback into the climate system. However, quantitative studies on the response of ET to large-scale vegetation restoration projects and climate change are still lacking, especially in drylands. To address this deficiency, this research examined the variation in ET since the implementation of restoration projects in the drylands of China in 2000-2018, and utilized quantitative analysis methods to investigate the effects of six environmental factors, including temperature (TEM), precipitation (PRE), solar radiation (RAD), vapour pressure deficit (VPD), soil moisture (SM), and leaf area index (LAI) on ET. Furthermore, a new method was proposed to detect the ET change caused by land use and land cover change (LUCC). The results indicated that ET showed a significant increasing trend (3.54 mm yr-1) during 2000-2018, and PRE was identified as a main influential factor with an ET contribution rate of more than 50%, especially in areas with insignificant vegetation greening. Additionally, the LAI had a major positive impact on ET in the areas of significant vegetation greening, and the contribution rate was nearly 40%. Furthermore, large-scale vegetation restoration expanded the area of high-transpiration vegetation types, and the ΔET (net variable quantity of ET caused by LUCC) increased obviously especially for the changes from cropland and grassland to forest, and barren land to grassland. These findings provide a new perspective for future assessments and further decision making regarding vegetation restoration projects in drylands.

Impacts of autofluorescence on fluorescence based techniques to study microglia.

BACKGROUND: Microglia, the resident immune cells in the central nervous system, accrue autofluorescent granules inside their cytoplasm throughout their lifespan. In this report, we studied the impacts of autofluorescence on widely used fluorescence-based techniques to study microglia, including flow cytometry, immunofluorescence staining, and live imaging. RESULTS: The failed attempt of using fluorescein isothiocyanate (FITC) conjugated antibody to detect lymphocyte-activation gene 3 protein in microglia prompted us to compare the sensitivity of FITC, phycoerythrin (PE) and allophycocyanin (APC) conjugated antibodies to detect surface protein expression in microglia. We found that PE outperformed FITC and APC as the fluorophore conjugated to antibody for flow cytometry by overcoming the interference from microglia autofluorescence. To identify the location and source of microglia autofluorescence, we did confocal imaging and spectral analysis of microglia autofluorescence on fixed brain tissues, revealing that microglia autofluorescence emitted from cytoplasmic granules and displayed a multi-peak emission spectrum. We recommended removing autofluorescence by lipofuscin removing agents when staining intracellular proteins in microglia with the immunofluorescence techniques. On live brain slices, autofluorescent granules reduced the amplitudes of calcium signals in microglial somata derived from GCaMP6s fluorescence and thus needed to be excluded when selecting regions of interest (ROI). CONCLUSIONS: In conclusion, autofluorescence is a critical factor to consider when designing experiments and interpreting results based on fluorescence-based techniques to study microglia.

Commentary: The global prevalence of depression and anxiety symptoms among college students and its influencing factors - a commentary on Li et al. (2022).

The commentary cites a study by Li and colleagues (2022) that conducted a comprehensive study of depression and anxiety symptoms among college students worldwide. We highlight the valuable contribution of this work to ongoing research, policy, and practice related to the early diagnosis and prevention of depression and anxiety symptoms in college students. The comprehensive report compensates for the lack of similar comprehensive studies in relevant areas and draws attention to the limitations of this and similar studies that require new solutions if well-designed, theoretically robust and implementable interventions are to be advanced. The author's work is timely and persuasive, providing important insights and theoretical support for specific work in the field of mental health of college students.

Preparation of ethyl cellulose particles with different morphologies through microfluidics.

The sizes and shapes of polymer particles determine their performance and application. In this paper, ethyl cellulose particles with different morphologies are generated through extraction and solidification in a microfluidic device with double T-junctions. Droplets of ethyl acetate containing ethyl cellulose are formed first, then, pure water is employed to extract the solvents in the droplets and the ethyl cellulose is solidified to form monodisperse particles. By changing the flow rates of the continuous phase and the dispersed phase and the concentration of ethyl cellulose, red-blood-cell-like, doughnut-like, dimpled and spherical particles are fabricated, and the regime of different particle morphologies is given. The more important is that the physical mechanisms and explanations of the formation of different particle morphologies are clearly disclosed by analyzing the circulation flows outside and inside the droplets. The flow patterns in the microchannel, and the diffusion and solidification properties of the molecules are the key factors that affect the final morphology of particles. Due to the circulation, there are two stagnation points at the front and rear of the droplet, and they are the approximate locations where the dimple in the dimpled particle, the hole in the doughnut-like particle and the two pits in the red-blood-cell-like particles are formed. These analysis and results are useful in flow chemistry, in the fabrication of particle materials, and so on.

Digitized Construction of Iontronic Pressure Sensor with Self-Defined Configuration and Widely Regulated Performance.

Flexible pressure sensors are essential components for wearable smart devices and intelligent systems. Significant progress has been made in this area, reporting on excellent sensor performance and fascinating sensor functionalities. Nevertheless, geometrical and morphological engineering of pressure sensors is usually neglected, which, however, is significant for practical application. Here, we present a digitized manufacturing methodology to construct a new class of iontronic pressure sensors with optionally defined configurations and widely modulated performance. These pressure sensors are composed of self-defined electrode patterns prepared by a screen printing method and highly tunable pressure-sensitive microstructures fabricated using 3D printed templates. Importantly, the iontronic pressure sensors employ an iontronic capacitive sensing mechanism based on mechanically regulating the electrical double layer at the electrolyte/electrode interfaces. The resultant pressure sensors exhibit high sensitivity (58 kPa-1), fast response/recovery time (45 ms/75 ms), low detectability (6.64 Pa), and good repeatability (2000 cycles). Moreover, our pressure sensors show remarkable tunability and adaptability in device configuration and performance, which is challenging to achieve via conventional manufacturing processes. The promising applications of these iontronic pressure sensors in monitoring various human physiological activities, fabricating flexible electronic skin, and resolving the force variation during manipulation of an object with a robotic hand are successfully demonstrated.

Printing Porous Carbon Aerogels for Low Temperature Supercapacitors.

Maintaining fast charging capability at low temperatures represents a significant challenge for supercapacitors. The performance of conventional porous carbon electrodes often deteriorates quickly with the decrease of temperature due to sluggish ion and charge transport. Here we fabricate a 3D-printed multiscale porous carbon aerogel (3D-MCA) via a unique combination of chemical methods and the direct ink writing technique. 3D-MCA has an open porous structure with a large surface area of ∼1750 m2 g-1. At -70 °C, the symmetric device achieves outstanding capacitance of 148.6 F g-1 at 5 mV s-1. Significantly, it retains a capacitance of 71.4 F g-1 at a high scan rate of 200 mV s-1, which is 6.5 times higher than the non-3D printed MCA. These values rank among the best results reported for low temperature supercapacitors. These impressive results highlight the essential role of open porous structures for preserving capacitive performance at ultralow temperatures.

Androgen Metabolism and Response in Prostate Cancer Anti-Androgen Therapy Resistance.

All aspects of prostate cancer evolution are closely related to androgen levels and the status of the androgen receptor (AR). Almost all treatments target androgen metabolism pathways and AR, from castration-sensitive prostate cancer (CSPC) to castration-resistant prostate cancer (CRPC). Alterations in androgen metabolism and its response are one of the main reasons for prostate cancer drug resistance. In this review, we will introduce androgen metabolism, including how the androgen was synthesized, consumed, and responded to in healthy people and prostate cancer patients, and discuss how these alterations in androgen metabolism contribute to the resistance to anti-androgen therapy.

[Chronic psychological stress exacerbates aortic medial calcification via glucocorticoids].

Chronic psychological stress can promote vascular diseases, such as hypertension and atherosclerosis. This study aims to explore the effects and mechanism of chronic psychological stress on aortic medial calcification (AMC). Rat arterial calcification model was established by nicotine gavage in combination with vitamin D3 (VitD3) intramuscular injection, and rat model of chronic psychological stress was induced by humid environment. Aortic calcification in rats was evaluated by using Alizarin red staining, aortic calcium content detection, and alkaline phosphatase (ALP) activity assay. The expression levels of the related proteins, including vascular smooth muscle cells (VSMCs) contractile phenotype marker SM22α, osteoblast-like phenotype marker RUNX2, and endoplasmic reticulum stress (ERS) markers (GRP78 and CHOP), were determined by Western blot. The results showed that chronic psychological stress alone induced AMC in rats, further aggravated AMC induced by nicotine in combination with VitD3, promoted the osteoblast-like phenotype transformation of VSMCs and aortic ERS activation, and significantly increased the plasma cortisol levels. The 11ß-hydroxylase inhibitor metyrapone effectively reduced chronic psychological stress-induced plasma cortisol levels and ameliorated AMC and aortic ERS in chronic psychological stress model rats. Conversely, the glucocorticoid receptor agonist dexamethasone induced AMC, promoted AMC induced by nicotine combined with VitD3, and further activated aortic ERS. The above effects of dexamethasone could be inhibited by ERS inhibitor 4-phenylbutyrate. These results suggest that chronic psychological stress can lead to the occurrence and development of AMC by promoting glucocorticoid synthesis, which may provide new strategies and targets for the prevention and control of AMC.

Investigating the folding mechanism of the N-terminal domain of ribosomal protein L9.

Protein folding is a popular topic in the life science. However, due to the limited sampling ability of experiments and simulations, the general folding mechanism is not yet clear to us. In this work, we study the folding of the N-terminal domain of ribosomal protein L9 (NTL9) in detail by a mixing replica exchange molecular dynamics method. The simulation results are close to previous experimental observations. According to the Markov state model, the folding of the protein follows a nucleation-condensation path. Moreover, after the comparison to its 39-residue ß-α-ß motif, we find that the helix at the C-terminal has a great influence on the folding process of the intact protein, including the nucleation of the key residues in the transition state ensemble and the packing of the hydrophobic residues in the native state.

Enhancing Li-Ion Affinity of Molybdenum Dioxide/Carbon Fabric to Achieve High Pseudocapacitance.

High-energy electrodes at high mass loadings (usually >8.0 mg cm-2 ) are desired for aqueous pseudocapacitors. Yet, how to overcome the thickness-dependent resistance increase of ion/electron transport in pseudocapacitive materials is still challenging. Herein, a high-performance electrode (denoted as AMC) adapted to high mass loading is achieved by promoting the Li-ion affinity of 3D MoO2 /carbon fabric. The experimental results and corresponding computational results reveal that the oxygen-activated surface of AMC, combined with the wettability and conductivity superiority of 3D graphite network, significantly facilitates the Li-ion adsorption and diffusion at the electrode/electrolyte interface, even at large thicknesses. Consequently, even at a high mass loading up to 8.1 mg cm-2 , the AMC electrode also displays an impressive specific capacity (567.5 C g-1 at 2.5 A g-1 ), substantially superior to most advanced pseudocapacitive electrodes. The strategy of boosting energy characteristic by enhancing the affinity of charge carriers is applicable to other pseudocapacitive electrodes.

Interlayer Engineering of α-MoO3 Modulates Selective Hydronium Intercalation in Neutral Aqueous Electrolyte.

Among various charge-carrier ions for aqueous batteries, non-metal hydronium (H3 O+ ) with small ionic size and fast diffusion kinetics empowers H3 O+ -intercalation electrodes with high rate performance and fast-charging capability. However, pure H3 O+ charge carriers for inorganic electrode materials have only been observed in corrosive acidic electrolytes, rather than in mild neutral electrolytes. Herein, we report how selective H3 O+ intercalation in a neutral ZnCl2 electrolyte can be achieved for water-proton co-intercalated α-MoO3 (denoted WP-MoO3 ). H2 O molecules located between MoO3 interlayers block Zn2+ intercalation pathways while allowing smooth H3 O+ intercalation/diffusion through a Grotthuss proton-conduction mechanism. Compared to α-MoO3 with a Zn2+ -intercalation mechanism, WP-MoO3 delivers the substantially enhanced specific capacity (356.8 vs. 184.0 mA h g-1 ), rate capability (77.5 % vs. 42.2 % from 0.4 to 4.8 A g-1 ), and cycling stability (83 % vs. 13 % over 1000 cycles). This work demonstrates the possibility of modulating electrochemical intercalating ions by interlayer engineering, to construct high-rate and long-life electrodes for aqueous batteries.

Simulation Study of the Plasticity of k-Turn Motif in Different Environments.

The k-turn is a widespread and important motif in RNA. According to the internal hydrogen bond network, it has two stable states, called N1 and N3. The relative stability between the states changes with the environment. It is able to accept different conformations in different environments. This is called the "plasticity" of a molecule. In this work, we study the plasticity of k-turn by the mixing REMD method in explicit solvent. The results are concluded as follows. First, N1 and N3 are almost equally stable when k-turn is in the solvent alone. The molecule is quite flexible as a hinge. However, after binding to different proteins, such as the proteins L7Ae and L24e, k-turn falls into one global minimum. The preferred state could be either N1 or N3. On the contrary, the other nonpreferred state becomes unstable with a weaker binding affinity to the protein. It reveals that RNA-binding protein is able to modulate the representative state of k-turn at equilibrium. This is in agreement with the findings in experiments. Moreover, free energy calculations show that the free energy barrier between the N1 and N3 states of k-turn increases in the complexes. The state-to-state transition is greatly impeded. We also give a deep discussion on the mechanism of the high plasticity of k-turn in different environments.