Asymmetrical electrohydrogenation of CO2 to ethanol with copper-gold heterojunctions.

Copper is distinctive in electrocatalyzing reduction of CO2 into various energy-dense forms, but it often suffers from limited product selectivity including ethanol in competition with ethylene. Here, we describe systematically designed, bimetallic electrocatalysts based on copper/gold heterojunctions with a faradaic efficiency toward ethanol of 60% at currents in excess of 500 mA cm-2. In the modified catalyst, the ratio of ethanol to ethylene is enhanced by a factor of 200 compared to copper catalysts. Analysis by ATR-IR measurements under operating conditions, and by computational simulations, suggests that reduction of CO2 at the copper/gold heterojunction is dominated by generation of the intermediate OCCOH*. The latter is a key contributor in the overall, asymmetrical electrohydrogenation of CO2 giving ethanol rather than ethylene.

Multiscale CO2 Electrocatalysis to C2+ Products: Reaction Mechanisms, Catalyst Design, and Device Fabrication.

Electrosynthesis of value-added chemicals, directly from CO2, could foster achievement of carbon neutral through an alternative electrical approach to the energy-intensive thermochemical industry for carbon utilization. Progress in this area, based on electrogeneration of multicarbon products through CO2 electroreduction, however, lags far behind that for C1 products. Reaction routes are complicated and kinetics are slow with scale up to the high levels required for commercialization, posing significant problems. In this review, we identify and summarize state-of-art progress in multicarbon synthesis with a multiscale perspective and discuss current hurdles to be resolved for multicarbon generation from CO2 reduction including atomistic mechanisms, nanoscale electrocatalysts, microscale electrodes, and macroscale electrolyzers with guidelines for future research. The review ends with a cross-scale perspective that links discrepancies between different approaches with extensions to performance and stability issues that arise from extensions to an industrial environment.

Allelic variation of PmCBF03 contributes to the altitude and temperature adaptability in Japanese apricot (Prunus mume Sieb. et Zucc.).

Japanese apricot is an important subtropical deciduous fruit tree in China, widely distributed in different altitude areas. How does it adapt to the different temperature environments in these areas? In this study, we identified a low-temperature transcription factor PmCBF03 on chromosome 7 through adaptive analysis of populations at different altitudes, which has an early termination single nucleotide polymorphism mutation. There were two different types of variation, PmCBF03A type in high-altitude areas and PmCBF03T type in low-altitude areas. PmCBF03A gene increased the survival rate, Fv/Fm values, antioxidant enzyme activity, and expression levels of antioxidant enzyme genes, and reducing electrolyte leakage and accumulation of reactive oxygen species in transgenic Arabidopsis under low temperature and freezing stress. Simultaneously, PmCBF03A gene promoted the dormancy of transgenic Arabidopsis seeds than wild-type. Biochemical analysis demonstrated that PmCBF03A directly bound to the DRE/CRT element in the promoters of the PmCOR413, PmDAM6 and PmABI5 genes, promoting their transcription and enhanced the cold resistance and dormancy of the overexpressing PmCBF03A lines. While PmCBF03T gene is unable to bind to the promoters of PmDAM6 and PmABI5 genes, leading to early release of dormancy to adapt to the problem of insufficient chilling requirement in low-altitude areas.

Bovine Serum Albumin Template-Mediated Fabrication of Ruthenium Dioxide/Multiwalled Carbon Nanotubes: High-Performance Electrochemical Dopamine Biosensing in Human Serum.

The presence of abnormal dopamine (DA) levels may cause serious neurological disorders, therefore, the quantitative analysis of DA and its related research are of great significance for ensuring health. Herein, the bovine serum albumin (BSA) template method has been proposed for the preparation of catalytically high-performance ruthenium dioxide/multiwalled carbon nanotube (RuO2/MWCNT) nanocomposites. The incorporation of MWCNTs has improved the active surface area and conductivity while effectively preventing the aggregation of RuO2 nanoparticles. The outstanding electrocatalytic performance of RuO2/MWCNTs has promoted the electro-oxidation of DA at neutral pH. The electrochemical sensing platform based on RuO2/MWCNTs has demonstrated a wide linear range (0.5 to 111.1 µM), low detection limit (0.167 µM), excellent selectivity, long-term stability, and good reproducibility for DA detection. The satisfactory recovery range of 94.7% to 103% exhibited by the proposed sensing podium in serum samples signifies its potential for analytical applications. The aforementioned results reveal that RuO2/MWCNT nanostructures hold promising aptitude in the electrochemical sensor to detect DA in real samples, further offering broad prospects in clinical and medical diagnosis.

Mitochondria-Targeting Multifunctional Fluorescent Probe toward Polarity, Viscosity, and ONOO- and Cell Imaging.

Abnormal changes occurring in the mitochondrial microenvironment are important markers indicating mitochondrial and cell dysfunction. Herein, we designed and synthesized a multifunctional fluorescent probe DPB that responds to polarity, viscosity, and peroxynitrite (ONOO-). DPB is composed of an electron donor (diethylamine group) and electron acceptor (coumarin, pyridine cations, and phenylboronic acid esters), in which the pyridine group with a positive charge is responsible for targeting to mitochondria. D-π-A structure with strong intramolecular charge transfer (ICT) and twisted intramolecular charge transfer (TICT) properties give rise to respond to polarity and viscosity. The introduction of cyanogroup and phenylboronic acid esters increases the electrophilicity of the probe, which is prone to oxidation triggered by ONOO-. The integrated architecture satisfies the multiple response requirements. As the polarity increases, the fluorescence intensity of probe DPB at 470 nm is quenched by 97%. At 658 nm, the fluorescence intensity of DPB increases with viscosity and decreases with the concentration of ONOO-. Furthermore, the probe is not only successfully used to monitor mitochondrial polarity, viscosity, and endogenous/exogenous ONOO- level fluctuations but also to distinguish cancer cells from normal cells by multiple parameters. Therefore, as-prepared probe provides a reliable tool for better understanding of the mitochondrial microenvironment and also a potential approach for the diagnosis of disease.

Mid-infrared silicon metasurfaces for near-field enhancement of molecular fingerprints.

Mid-infrared dielectric metasurfaces are promising fundamental building blocks for integrated sensing with high sensitivity, compositional selectivity, and low loss. We have designed and fabricated a silicon metasurface with resonance properties in the 4∼5 µm mid-infrared region and a volume enhancement of up to 9 times. Benchmark FTIR characterizations of solutions of tungsten hexacarbonyl molecules showed a detection limit of 1 mg/mL without the usage of surface enrichment treatment. We further rationalize the detection limit of the molecules-nanostructure open interface with volume field enhancement analysis. Our results show that mid-infrared silicon metasurfaces may be a suitable platform for potential integration with microfluidic for in vivo detection.

Hypoxic White Matter Injury and Recovery After Reoxygenation in Adult Mice: Magnetic Resonance Imaging Findings and Histological Studies.

Cognitive dysfunction and brain white matter (WM) injury have been found in adults exposed to hypoxia. However, the mechanisms underlying these impairments remain unclear, and moreover, it is also unclear whether these impairments are reversible after reoxygenation. In this study, adult male mice were exposed to hypoxia for 15 days at a simulated altitude of 4300 m and then reoxygenated for 2 months. Control mice were raised under normoxic conditions. Mice showed a significant decrease in arterial oxygen saturation (SaO2) and an increase in heart rate and breath rate after hypoxic exposure, and they displayed anxiety-like emotion and impaired cognitions. Hypoxic mice showed decreased brain WM fractional anisotropy (FA) and increased mean diffusion (MD) mainly in the corpus callosum and internal capsule. The reason for the adult brain WM injury was myelin rather than axon. Further, the myelin injury was due to the obstruction of oligodendrocyte precursor cells (OPCs) differentiation and eventually led to behavioral deficits. More importantly, the changes in physiological indicators, behavioral disorders, and WM injury caused by hypoxia can be recovered after reoxygenation. Taken together, our data indicate that adult brain WM injury caused by hypoxia is reversible after reoxygenation and enhancing OPCs differentiation may be a promising therapy for clinical hypoxic diseases associated with brain injury. Schematic diagram of brain WM and behavioral changes induced by hypoxia/reoxygenation in adult mice.

A bifunctional fluorescence probe for dual-channel detecting of mitochondrial viscosity and endogenous/exogenous peroxynitrite.

The irregular viscosity in the mitochondrial can induce mitochondrial dysfunction. The content of peroxynitrite (ONOO-) is related to various physiological and pathological processes. However, many mitochondrial probes only realized the detection of viscosity or ONOO- in single channel, thus it is necessary to explore single fluorescence probe for dual-detecting mitochondrial viscosity and ONOO-. In this work, we designed and synthesized a novel fluorescence probe (PV) for dual-detecting viscosity and ONOO-, which was composed by intergrating a ONOO-- responsive arlyboronate with a twisting intramolecular charge transfer (TICT) mechanism and possessed the mitochondria-targeting ability due to its pyridinium cation. PV exhibited a significant increase in viscosity with red emission at 582 nm and high sensitivity to ONOO- levels with yellow emission at 507 nm. PV was also applied to living systems (including living cells and zebrafish) for viscosity and ONOO- detection using two different channels. Moreover, the ability of PV to track mitophagy may make ONOO- a powerful tool for its role in mitophagy.

Assessment of Resonant Acoustic Mixing for Low-Dose Pharmaceutical Powder Blends.

Obtaining a homogeneous low-dose pharmaceutical powder blend without multi-step processing remains a challenge. One promising technology to address this risk is resonant acoustic mixing (RAM). In this study, the performance of a laboratory resonant acoustic mixer (LabRAM) was studied at low active pharmaceutical ingredient (API) concentrations (0.1-0.5% w/w), using three commercial grades of a model API (Acetaminophen) and diluents with varying physical properties. The performance was assessed by evaluating blend uniformity (BU) and capsule content uniformity (CU) as a function of mixing time. Overall, the LabRAM achieved acceptable BU in a single step even at 0.1% w/w drug loading. A reduction in API primary particle size led to improved mixing efficiency and uniformity. Moreover, the presence of surface cavities in the diluents used appeared to have led to improved uniformity. The results demonstrated that RAM could achieve uniform powder blends without multi-step processing, for low-dose formulations.

Alizarin-based molecular probes for the detection of hydrogen peroxide and peroxynitrite.

Phenol fluorophores are a large family of fluorophores, which have attracted more and more attention in the design of probes. Using the self-assembly of aromatic boronic acid with Alizarin Red S (ARS) and Gallein (GAL), the novel chemosensors ARS-CBA and GAL-CBA were provided for hydrogen peroxide (H2O2), which demonstrated their ability to detect H2O2 with indicator displacement assay (IDA) by colorimetric and electrochemical measurements. After ARS-CBA and GAL-CBA reacted with H2O2, the systems displayed a red-shifted visible color change in aqueous media and off-on electrochemical signals showing generation of phenol. The chemosensor ARS-CBA also had good performance in fluorometric measurements and turn-off fluorescent response indicated removal of aromatic boronic acid. In addition, a designed near-infrared (NIR) dual-modal fluorescent probe alizarin blue S (ABS) was used for peroxynitrite (ONOO-) with a visible colorimetric change in dimethyl sulfoxide (DMSO) and "on-off" fluorescent response indicating the oxidation of hydroxyl. The flexible Phenol fluorophores are allowed to prepare multiple fluorescent probes towards H2O2 or ONOO- for environmental and physiological applications.

Visualization of polarity changes in endoplasmic reticulum (ER) autophagy and rheumatoid arthritis mice with near-infrared ER-targeted fluorescent probe.

The crucial cellular activities for maintaining normal cell functions heavily rely on the polarity of the endoplasmic reticulum (ER). Understanding how the polarity shifts, particularly in the context of ER autophagy (ER-phagy), holds significant promise for advancing knowledge of disorders associated with ER stress. Herein, a polarity-sensitive fluorescent probe CDI was easily synthesized from the condensation reaction of coumarin and dicyanoisophorone. CDI was composed of coumarin as the electron-donating moiety (D), ethylene and phenyl ring as the π-conjugation bridge, and malononitrile as the electron-accepting moiety (A), forming a typical D-π-A molecular configuration that recognition in the near-infrared (NIR) region. The findings suggested that as the polarity increased, the fluorescence intensity of CDI decreased, and it was accompanied by a redshift of emission wavelength at the excitation wavelength of 524 nm, shifting from 641 nm to 721 nm. Significantly, CDI exhibited a notable ability to effectively target ER and enabled real-time monitoring of ER-phagy induced by starvation or drugs. Most importantly, alterations in polarity can be discerned through in vivo imaging in mice model of rheumatoid arthritis (RA). CDI has been proven effective in evaluating the therapeutic efficacy of drugs for RA. ER fluorescent probe CDI can be optically activated in lysosomes, providing a sensitive tool for studying ER-phagy in biology and diseases.

Edaravone-loaded poly(amino acid) nanogel inhibits ferroptosis for neuroprotection in cerebral ischemia injury.

Neurological injury caused by ischemic stroke is a major cause of permanent disability and death. The currently available neuroprotective drugs fail to achieve desired therapeutic efficacy mainly due to short circulation half-life and poor blood-brain barrier (BBB) permeability. For that, an edaravone-loaded pH/glutathione (pH/GSH) dual-responsive poly(amino acid) nanogel (NG/EDA) was developed to improve the neuroprotection of EDA. The nanogel was triggered by acidic and EDA-induced high-level GSH microenvironments, which enabled the selective and sustained release of EDA at the site of ischemic injury. NG/EDA exhibited a uniform sub-spherical morphology with a mean hydrodynamic diameter of 112.3 ± 8.2 nm. NG/EDA efficiently accumulated at the cerebral ischemic injury site of permanent middle cerebral artery occlusion (pMCAO) mice, showing an efficient BBB crossing feature. Notably, NG/EDA with 50 µM EDA significantly increased neuron survival (29.3%) following oxygen and glucose deprivation by inhibiting ferroptosis. In addition, administering NG/EDA for 7 d significantly reduced infarct volume to 22.2% ± 7.2% and decreased neurobehavioral scores from 9.0 ± 0.6 to 2.0 ± 0.8. Such a pH/GSH dual-responsive nanoplatform might provide a unique and promising modality for neuroprotection in ischemic stroke and other central nervous system diseases.

Multifunctional Mitochondria-Targeting Near-Infrared Fluorescent Probe for Viscosity, ONOO-, Mitophagy, and Bioimaging.

Irregularities in mitochondrial viscosity and peroxynitrite (ONOO-) concentration can lead to mitochondrial dysfunction. It is still a great challenge to develop near-infrared (NIR) fluorescent probes to simultaneously detect viscosity, endogenous ONOO-, and mitophagy. Herein, a multifunctional mitochondria-targeting NIR fluorescent probe P-1 was first synthesized for simultaneously detecting viscosity, ONOO-, and mitophagy. P-1 used quinoline cations as a mitochondrial targeting moiety, arylboronate as an ONOO- responsive group, and detected the change of viscosity by the twisted internal charge transfer (TICT) mechanism. The probe has an excellent response to the viscosity during inflammation by lipopolysaccharides (LPSs) and mitophagy induced by starvation at 670 nm. The viscosity changes of the probe induced by nystatin in zebrafish showed that P-1 was able to detect microviscosity in vivo. P-1 also showed good sensitivity with a detection limit of 6.2 nM for ONOO- detection and was successfully applied to the endogenous ONOO- detection in zebrafish. Moreover, P-1 has the ability to distinguish between cancer cells and normal cells. All of these features make P-1 a promising candidate to detect mitophagy and ONOO- -associated physiological and pathological processes.

Recent advances in fluorescent probes for dual-detecting ONOO- and analytes.

Although peroxynitrite (ONOO-) plays an essential role in cellular redox homeostasis, its excess ONOO- will affect the normal physiological function of cells. Therefore, real-time monitoring of changes in local ONOO- will contribute to further revealing the biological functions. Reliable and accurate detection of biogenic ONOO- will definitely benefit for disentangling its complex functions in living systems. In the past few years, more fluorescent probes have been developed to help understand and reveal cellular ONOO- changes. However, there has been no comprehensive and critical review of multifunctional fluorescent probes for cellular ONOO- and other analytes. To highlight the recent advances, this review first summarized the recent progress of multifunctional fluorescent probes since 2018, focusing on molecular structures, response mechanisms, optical properties, and biological imaging in the detection and imaging of cellular ONOO- and analytes. We classified and discussed in detail the limitations of existing multifunctional probes, and proposed new ideas to overcome these limitations. Finally, the challenges and future development trends of ONOO- fluorescence probes were discussed. We hoped this review will provide new research directions for developing of multifunctional fluorescent probes and contribute to the early diagnosis and treatment of diseases.

Positive relationships of character strengths with fitness and physical activity in primary school children.

Objective: This study is the first to examine the relationship between character strengths, objective physical fitness, and physical activity in primary school children. Design: This cross-sectional study was conducted in 2016 and 2017 at a school in Japan. Main Outcome Measures: We obtained informed consent from 236 fourth-grade students; 122 fifth-grade students; and 142 sixth-grade students. After excluding participants with missing data, 473 children (247 boys and 226 girls; aged 9-12 years) with informed consent were included in the study. We measured character strengths, physical fitness, and/or physical activity of fourth- to sixth-grade participants. Results: Among boys, the total score of physical fitness was significantly associated with perseverance-honesty, courage-ideas, compassion-gratitude, and fairness-care (p < 0.05). Among girls, the total score of physical fitness was significantly associated with perseverance-honesty, courage-ideas, and compassion-gratitude (p < 0.05). Regarding the relationship between character strengths and physical activity, perseverance-honesty was significantly associated with total steps and moderate-to-vigorous physical activity (MVPA), whereas courage ideas were significantly associated with total steps (p < 0.05) in boys. In girls, perseverance-honesty was associated with MVPA (p < 0.05). Conclusions: Our findings revealed that character strengths are positively associated with objective physical fitness and physical activity in primary-school children.

A dual-mode optical fiber sensor for SERS and fluorescence detection in liquid.

The in vivo detection of biomarkers in a liquid environment is very important for the early diagnosis of diseases. Spectroscopy methods are employed in ultraviolet-visible-infrared wavelengths, fluorescence or Raman spectra are detected for clinical diagnose. The dual-mode image can provide more diagnostic information and has been realized in some research work. However, there is still lacking simple and sensitive dual-mode sensors to satisfy the in vivo detecting demands. In this paper, a dual-mode fiber sensor for Surface-enhanced Raman Scattering (SERS) and fluorescence detection is proposed. The sensor is formed by a tapered optical fiber, half of the fiber tip surface is coated with Ag nanoparticles. In the detection of Rhodamine 6G (R6G) aqueous solution, the minimum detectable concentrations in SERS and fluorescence tests are of the same order of magnitude. By combining the Raman spectral features and the fluorescence intensity, the recognition and quantitation of target molecules were obtained reliably. It is the first time, to our knowledge, that the Raman-fluorescence dual-mode detection is realized in one single fiber, which was manufactured with micro-machinery techniques. It is a label-free, general-purpose fiber sensor, which can be applied for liquid biopsy, helping to diagnose and treat diseases in vivo.

Brain Structural and Functional Alterations in Native Tibetans Living at High Altitude.

Tibetans have adapted to high altitude environments. However, the genetic effects in their brains have not been identified. Twenty-five native Tibetans living in Lhasa (3650 m) were recruited for comparison with 20 Han immigrants who originated from lowlands and had been living in Lhasa for two years. The physiological characteristics, brain structure and neuronal spontaneous activity were investigated. Compared with Han immigrants, Tibetans showed higher peripheral oxygen saturation (SpO2), and lower heart rate, red blood cell counts, hematocrit, and hemoglobin. Tibetans showed increased gray matter volume in the visual cortex, hippocampus, and rectus; increased the amplitudes of low-frequency fluctuations (ALFF) values in the left putamen and left fusiform gyrus; and decreased voxel-mirrored homotopic connectivity (VMHC) values in the precentral gyrus. Moreover, Tibetans have decreased functional connectivity (FC) between the left precentral gyrus and the frontal gyrusand right precuneus. In Tibetans and Han immigrants, hemoglobin and hematocrit were negatively correlated with total gray matter volume in males, SpO2 was also positively correlated with ALFF in the left fusiform gyrus, while hemoglobin, and hematocrit were positively correlated with VMHC in the precentral gyrus and FC in the precentral gyrus with other brain regions, SpO2 was also found to be negatively correlated with VMHC in the precentral gyrus, and hemoglobin and hematocrit were negatively correlated with ALFF in the left putamen and left fusiform gyrus. In summary, genetic mutations may result in modulation of some brain regions, which was further confirmed by the identification of correlations with hemoglobin and hematocrit in these regions.

High Concentration of Fermentable Sugars Prepared from Steam Exploded Lignocellulose in Periodic Peristalsis Integrated Fed-Batch Enzymatic Hydrolysis.

High concentrations of fermentable sugars are a demand for economical bioethanol production. A single process strategy cannot comprehensively solve the limiting factors in high-solid enzymatic hydrolysis. The multiple intensification strategies in this study achieved the goal of preparing high-concentration fermentable sugars of corn stalk with high solid loading and low enzyme loading. First, steam explosion pretreatment enhanced the hydrophilicity of substrates and enzymatic accessibility. Second, periodic peristalsis was used to improve the mass transfer efficiency and short the liquefaction time. Additionally, fed-batch feeding and enzyme reduced the enzyme loading. Ultimately, the intensification strategies above showed that the highest fermentable sugar content was 313.8 g/L with a solids loading as much as 50% (w/w) and enzyme loading as low as 12.5 FPU/g DM. Thus, these multiple intensification strategies were promising in the high-solid enzymatic hydrolysis of steam-exploded lignocellulose.

Rapid determination of ethanol content based on an optical fiber-device and R6G-indicator.

A rapid method for the determination of ethanol content is proposed and tested. A fluorescence detecting system, with a multimode fiber (MMF) sensing head, is employed. Rhodamine 6G (R6G) is applied as the fluorescent indicator. In the R6G aqueous solution, the molecules aggregate at high concentration, causing fluorescence quenching. Nevertheless, aggregation and quenching rarely occur in ethanol. Taking an ethanol and water mixture as the solvent, the photoluminescence (PL) intensity reflects the aggregation degree and the ethanol content. Based on this phenomenon, the contents of the ethanol-water mixture were measured through PL intensity detection. A limit of detection (LOD) at ∼0.1 vol% level was obtained in the range of 0-100%. Commercial Chinese baijiu and rubbing alcohol were tested and the results obtained were consistent with the label values. The detecting system is compact and of low-cost, and the detecting method is rapid, accurate and repeatable. There is good prospect of applications for the determination of ethanol content on-site.

Piperazine-Based Mitochondria-Immobilized pH Fluorescent Probe for Imaging Endogenous ONOO- and Real-Time Tracking of Mitophagy.

ONOO- is mainly produced in mitochondria, and dysfunctional and damaged mitochondria are degraded in lysosomes through autophagy, so it is important to synthesize a single probe for dual detection of ONOO- and mitophagy. Unfortunately, mitochondria-immobilized fluorescent probes for dual detection of ONOO- and mitophagy have not yet been developed. Hence, we first reported a piperazine-based mitochondria-immobilized red-emitting fluorescent probe (PMR), which not only can detect ONOO- but also could be used to image cellular mitophagy by the pH variations because of the protonation of the piperazine moiety. PMR was designed and prepared by introducing a piperazine ring as the pH response group, a lipophilic cation as the targeting mitochondria moiety, and benzyl chloride for immobilizing mitochondrial proteins through thiol groups. PMR displayed an enhanced fluorescence response at 640 nm through mitochondrial acidification. Using these advantages of PMR, which was successfully used for visualizing the mitophagy process induced by rapamycin or starvation, and chloroquine can inhibit rapamycin-induced mitophagy and prevent the fusion of autophagosomes and lysosomes. PMR also showed good sensitivity with a detection limit of 23 nM to ONOO-, which was successfully applied in imaging exogenous/endogenous ONOO-. Combining the above design, PMR may be used to study the detailed function of the mitophagy and ONOO--associated physiological and pathological processes.