Enhanced Photocatalytic Activities of Sodium Borohydride-Calcined Magnetic Manganese Ferrite Nanoparticles.

The synthesis, enhancement, and maintenance of magnetite-based catalyst nanoparticles (NPs) are important for photocatalytic activity and recovery rates. We used a sodium borohydride (NaBH4) calcination method to modify MnFe2O4 nanoparticles to optimize their performance in the photocatalytic oxidation of 2,5-hydroxymethylfurfural. The results indicated a 94% increase in photocatalytic efficiency, while magnetic assessments performed using a vibrating sample magnetometer showed an 8.9% improvement in magnetic properties without degradation. These findings show the dual benefits of increased photocatalytic performance with strong magnetic properties, which are important for the application and reusability of photocatalysts. The recycling of these photocatalysts reduces secondary pollution and increases the process cost-effectiveness. These results contribute to the solution of problems with the use of photocatalytic materials.

Reduction-Assisted Calcination Enhances the Photocatalytic Activity of ZnO and WO3 Nanoparticles in Biomass Conversion.

Rising energy needs and environmental issues have prompted the creation of effective and affordable photocatalysts for converting biomass. Utilizing abundant biomass, oxidation of 5-hydroxymethylfurfural (HMF) emerges as a method for generating high-value chemicals from biomass, offering an alternative to fossil fuels. We synthesized defect-engineered metal oxides (ZnO and WO3) by calcination with NaBH4 as a reducing agent. Atomic-level analyses identified oxygen vacancy defects induced by the reduction of metal ions within the metal oxide nanoparticles. Further analysis showed an unchanged band gap but an up to 4-fold increase in current density. This enhancement is attributed to the trapping of electrons in defect sites created during the calcination process. The formation of new electron donor states hindered photogenerated electron-hole recombination, enhancing the photocatalytic efficiency of the metal oxide. The photocatalytic degradation yield of HMF was over 95%, and the selective organic products 2,5-diformylfuran (DFF) and 2,5-furandicarboxylic acid (FDCA) were obtained without byproducts. Kinetic studies demonstrated that the photocatalytic conversion reaction rates were accelerated by up to 3.5-fold. Improved photocatalytic activity for HMF oxidation was achieved by introducing oxygen vacancy defects upon the reduction of metal ions within the metal oxides. Our results provide a promising approach for designing efficient photocatalysts.

Unveiling the Nanocluster Conversion Pathway for Highly Monodisperse InAs Colloidal Quantum Dots.

Colloidal quantum dots (CQDs) have garnered significant attention in nanoscience and technology, with a particular emphasis on achieving high monodispersity in their synthesis. Recent advances in understanding the chemistry of reaction intermediates such as magic-sized nanoclusters (MSC) have paved the way for innovative synthetic strategies. Notably, monodisperse CQDs of various compositions, including indium phosphide, indium arsenide, and cadmium chalcogenide, have been successfully prepared using nanocluster intermediates as single-source precursors. Still, the early stage conversion chemistry of these nanoclusters preceding CQD formation has not been fully unveiled yet. Herein, we report the first-order conversion of amorphous nanoclusters (AMCs) to InAs MSCs prior to the formation of CQDs. We find that MSC, isolated via gel-permeation chromatography, is more stable than purified AMCs, as demonstrated in various chemical and thermolytic reactions. While the surface of InAs AMCs and MSC is similarly bound with carboxylate ligands, detailed structural analyses employing synchrotron X-ray scattering and X-ray absorption spectroscopy unveil subtle distinctions arising from the distinct surface properties and structural disorder characteristics of InAs nanoclusters. We propose that InAs AMCs undergo a surface reduction and structural ordering process, resulting in the formation of an InAs MSC in a thermodynamically local minimum state. Furthermore, we demonstrate that both types of nanoclusters serve as viable precursors, providing a similar monomer supply rate at elevated temperatures of around 300 °C. This study offers invaluable insights into the interplay of structure and chemical stability in binary nanoclusters, enhancing our ability to design these nanoclusters as precursors for highly monodisperse CQDs.

Synergistic Interaction between Ruthenium Catalysts and Grafted Niobium on SBA-15 for 2,5-Furandicarboxylic Acid Production Using 5-Hydroxymethylfurfural.

This study entailed the synthesis of Ru nanocatalyst decorated on Nb-grafted SBA-15. A Nb-grafted SBA-15 support with varying Nb contents was utilized as a support for the Ru nanoparticles. The effect of Nb grafting on the immobilized Ru nanoparticle catalyst was systematically investigated, and its catalytic performance in the synthesis of furandicarboxylic acid using 5-hydroxymethylfurfural under base-free reaction conditions was evaluated. The results indicate the increased productivity of the Ru@Nb-grafted SBA-15 catalyst with a yield exceeding 95%, representing a significant advancement in catalysis. This study also affords insights into the complex relationship between the catalytic activity and selectivity and its unique surface attributes. Moreover, acidic sites were created, and the electron density within the active sites was modulated by monomeric Nb oxide species on the SBA-15. Additionally, the role of high-electron-density Ru atoms in facilitating the efficient adsorption and activation of the reactant, resulting in enhanced catalytic efficacy, was highlighted.

Feasibility of Isokinetic Training to Modify Coupling of Upper Limb Muscle Synergy Activation in Stroke-affected Upper Limb.

Abnormal intermuscular coordination in stroke-affected upper limbs contributes to motor deficits after stroke. In particular, abnormalities in the activation of upper limb muscle synergies after stroke were demonstrated for endpoint force control during isokinetic exercises. This study aimed to investigate the feasibility of isokinetic training to alter these abnormal synergy activations and improve motor control. Muscle synergies and Wolf Motor Function Test Functional Ability Scale (WMFT-FAS) score were compared before and after three weeks of electromyography-based training. The proposed training changed the synergy activation and improved the WMFT-FAS score in a chronic stroke survivor while preserving the muscle weights of the synergies.Clinical Relevance- This study presents the feasibility of neuromuscular training to modify the activation of upper limb muscle synergies against stroke-specific patterns of intermuscular coordination and improve WMFT-FAS score.

Expanding the repertoire of intermuscular coordination patterns and modulating intermuscular connectivity in stroke-affected upper extremity through electromyogram-guided training: a pilot study.

Abnormal intermuscular coordination is a major stroke-induced functional motor impairment in the upper extremity (UE). Previous studies have computationally identified the abnormalities in the intermuscular coordination in the stroke-affected UE and their negative impacts on motor outputs. Therefore, targeting the aberrant muscle synergies has the potential as an effective approach for stroke rehabilitation. Recently, we verified the modifiability of the naturally expressed muscle synergies of young able-bodied adults in UE through an electromyographic (EMG) signal-guided exercise protocol. This study tested if an EMG-guided exercise will induce new muscle synergies, alter the associated intermuscular connectivity, and improve UE motor outcome in stroke-affected UE with moderate-to-severe motor impairment. The study used the six-week isometric EMG signal-guided exercise protocol that focused on independently activating two specific muscles, the biceps and brachioradialis, to develop new muscle activation groups. The study found that both the stroke and age-matched, able-bodied groups were able to develop new muscle coordination patterns through the exercise while habitual muscle activation was still available, which led to improvements in the motor control of the trained arm. In addition, the results provided preliminary evidence of increased intermuscular connectivity between targeted muscles in the beta-band frequencies for stroke patients after training, suggesting a modulation of the common neural drive. These findings suggest that our isometric exercise protocol has the potential to improve stroke survivors' performance of UE in their activities in daily lives (ADLs) and, ultimately, their quality of life through expanding their repertoire of intermuscular coordination.Clinical Relevance- This study shows the feasibility of expanding the intermuscular coordination pattern in stroke-affected UE through an isometric EMG-guided exercise which positively affects task performance and intermuscular connectivity.

Relevance of Upper Limb Muscle Synergies to Dynamic Force Generation: Perspectives on Rehabilitation of Impaired Intermuscular Coordination in Stroke.

This study investigated the impact of stroke on the control of upper limb endpoint force during isokinetic exercise, a dynamic force-generating task, and its association with stroke-affected muscle synergies. Three-dimensional upper limb endpoint force and electromyography of shoulder and elbow muscles were collected from sixteen chronic stroke survivors and eight neurologically intact adults. Participants were instructed to control the endpoint force direction during three-dimensional isokinetic upper limb movements. The endpoint force control performance was quantitatively evaluated in terms of the coupling between forces in orthogonal directions and the complexity of the endpoint force. Upper limb muscle synergies were compared between participants with varying levels of endpoint force coupling. The stroke survivors generating greater force abnormality than the others exhibited interdependent activation profiles of shoulder- and elbow-related muscle synergies to a greater extent. Based on the relevance of synergy activation to endpoint force control, this study proposes isokinetic training to correct the abnormal synergy activation patterns post-stroke. Several ideas for implementing effective training for stroke-affected synergy activation are discussed.

Corrigendum to "Engineering exosomes and their application in cardiovascular field: Bibliometric analysis from 2002 to 2022" [Heliyon 9(8) (August 2023) e18809].

[This corrects the article DOI: 10.1016/j.heliyon.2023.e18809.].

Enhancement of Sulfur Source-Dependent Zn Vacancies in Different Photocatalytic Performances of ZnIn2S4 Nanoparticles.

This study focuses on the synthesis and investigation of ZnIn2S4 nanoparticle (NP) photocatalysts treated with different sulfur sources, thioacetamide (TAA), or thiourea (TU), to explore their wavelength-dependent photocatalytic activity. The research aims to understand the impact of Zn vacancies present on the surface of ZnIn2S4 NPs. The investigation involves electron spin resonance and in situ X-ray photoelectron spectroscopy to study the photocatalytic activity of ZnIn2S4-TU and ZnIn2S4-TAA NPs, following the characterization of surface morphology and electronic properties using high-resolution transmission electron microscopy and X-ray diffraction. Additionally, the study delves into the wavelength-dependent photocatalytic degradation (PCD) activity of the ZnIn2S4 NPs using 2,5-hydroxymethylfurfural (HMF) across a wide range. Notably, the selective oxidation of HMF using ZnIn2S4-TU NPs resulted in the formation of 2,5-furandicarboxylic acid (FDCA) via 2,5-diformylfuran, with an efficiency exceeding 40% over the broad wavelength range. The research demonstrates that the irradiation wavelength for PCD is influenced by the number of defect structures introduced into the ZnIn2S4 NPs through the sulfur source.

Performance Promotion of Multipurpose Catalysts Using Increased Oxygen Vacancy Amounts by Charge-Mismatched Doping.

Modulating the oxygen vacancy (V0) in nanostructures has opened a new avenue for efficient catalyst design, facilitating biomass oxidation reactions and electrocatalytic properties. In this study, we have investigated the properties of NiO-based catalysts with varying degrees of V0 achieved through ion doping of the catalyst with cations of different oxidation states (TM3+) or the same valence state (TM2+) as Ni2+ in the NiO matrix. By introducing charge-mismatched dopants, we enhanced the concentration of V0 in the NiO catalyst, resulting in remarkable selectivity (∼50%) for the conversion of 2,5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), as well as a lower overpotential in the oxygen evolution reaction (OER). We believe that charge-mismatched doping offers a novel avenue for optimizing defect engineering in oxide-based catalysts, which can enable more efficient biomass conversion and water splitting. These findings have made a significant contribution to the field of multipurpose catalysis and hold the potential to inspire new catalyst designs that would usher in a more sustainable future.

Engineering exosomes and their application in cardiovascular field: Bibliometric analysis from 2002 to 2022.

Cardiovascular disease (CVD) is the leading cause of death around the world, warranting an increasing number of studies for its treatment. Among all of its therapeutical strategies, engineered exosomes are attracting growing attention due to their excellent biocompatibility, non-immunogenicity, and favorable plasticity. Despite its increasing popularity, there is yet to be a bibliometric analysis regarding the application of exosomes in CVD treatment. Therefore, the present study assessed the current trends in engineered exosomes in treating CVD by conducting a bibliometric analysis. All associated literatures published between years 2002-2022 were collected, through the Web of Science Core Collection. Our results showed that related studies robustly increased in 2020, followed by a gradual increase from 2020 to 2022, indicating that this field attracted growing attention. Additionally, we described critical network of countries, institutions, authors, top-cited references, and keywords. The present bibliometric study provides systematic observations on engineering exosomes in treating CVD, reveals potential challenges and future direction for additional studies, and may inspire more researchers to commit to investigating treatments for CVD.

Intravenous thrombolysis for acute ischemic stroke: From alteplase to tenecteplase.

Stroke is one of the primary causes of morbidity and death worldwide. While intravenous (IV) thrombolysis with alteplase has been widely proven to be beneficial for acute ischemic stroke patients, it still has many limitations. Tenecteplase, a revised version of alteplase, is a potential alternative IV thrombolytic agent that has benefits over alteplase. The aim of this mini-review is to summarize the advancements in IV thrombolysis for severe ischemic stroke, specifically the development and transition from alteplase to tenecteplase.

Room temperature processed protective layer for printed silver electrodes.

Low-temperature processed printed silver electrodes pave the way for electrical connections in flexible substrates with reduced energy consumption. Despite their excellent performance and simple process, printed silver electrodes' poor stability limits their applications. This study demonstrates a transparent protective layer without thermal annealing for printed silver electrodes, which maintains its electrical properties for a long period of time. A fluoropolymer, specifically a cyclic transparent optical polymer (CYTOP), was used as a protective layer for silver. The CYTOP is room temperature processable and chemically stable against carboxyl acid. The introduction of the CYTOP film on the printed silver electrodes mitigates the chemical reaction between silver and carboxyl acid, thereby elongating its lifetime. Under heated acetic acid, the printed silver electrodes with a CYTOP protective layer maintained their initial resistance for up to 300 hours, while the electrodes without a protective layer were damaged within a few hours. A microscopic image shows that the protective layer enables printed electrodes to maintain their shape without damage. Hence, the protective layer guarantees the accurate and reliable performance of electronic devices with printed electrodes under actual operating conditions. This research will contribute to designing chemically reliable flexible devices in the near future.

Hypothermic neuroprotection by targeted cold autologous blood transfusion in a non-human primate stroke model.

Over decades, nearly all attempts to translate the benefits of therapeutic hypothermia in stroke models of lower-order species to stroke patients have failed. Potentially overlooked reasons may be biological gaps between different species and the mismatched initiation of therapeutic hypothermia in translational studies. Here, we introduce a novel strategy of selective therapeutic hypothermia in a non-human primate ischemia-reperfusion model, in which autologous blood was cooled ex vivo and the cool blood transfusion was administered at the middle cerebral artery just after the onset of reperfusion. Cold autologous blood cooled the targeted brain rapidly to below 34 °C while the rectal temperature remained around 36 °C with the assistance of a heat blanket during a 2-h hypothermic process. Therapeutic hypothermia or extracorporeal-circulation related complications were not observed. Cold autologous blood treatment reduced infarct sizes, preserved white matter integrity, and improved functional outcomes. Together, our results suggest that therapeutic hypothermia, induced by cold autologous blood transfusion, was achieved in a feasible, swift, and safe way in a non-human primate model of stroke. More importantly, this novel hypothermic approach conferred neuroprotection in a clinically relevant model of ischemic stroke due to reduced brain damage and improved neurofunction. This study reveals an underappreciated potential for this novel hypothermic modality for acute ischemic stroke in the era of effective reperfusion.

Changes in Cerebrovascular Procedures and Outcomes During COVID-19 Using the National Surgery Quality Improvement Project.

OBJECTIVE: Explore the consequences of the coronavirus pandemic (COVID-19) on patients suffering from cerebrovascular disorders necessitating interventions. METHODS: Using the National Surgical Quality Improvement Program database, patients with cerebrovascular disease who underwent procedures before (2018-2019) and during (2020-2021) COVID-19 were identified. ICD-10 and Current Procedure Terminology codes were employed to classify diseases and elective cases, respectively. Our study analyzed variations in diagnoses, procedures, demographics, mortality and morbidity likelihood scores, and outcomes. Analysis was conducted using R 4.2.1 with tidyverse, haven, and Ime4 packages. Statistical significance was defined as P < 0.05. RESULTS: There was a significant rise in cerebrovascular accidents (CVAs) (9.96% vs. 12.28%) and a decrease in elective carotid endarterectomies (92.30% vs. 87.22%). Carotid stenting increased significantly (7.63% vs. 12.62%), and mortality probability scores rose for CVAs and carotid interventions. Ethnic (Hispanic) and racial minorities (Asians and Black/African American) were disproportionately affected (P < 0.001). Conditions from delayed care increased, and total operative times rose (117.46 vs. 124.33 minutes). Various patient outcomes worsened (P < 0.05), and multivariate analyses showed Hispanic patients had higher mortality and morbidity probability scores (P < 0.05). CONCLUSIONS: The pandemic led to more severe disease progression and reduced diagnoses due to screening delays, indicating deferred care. Prolonged operative times, extended hospital stays, and worsening outcomes, including infections and thrombotic events, hint at the repercussions of persistent staff shortages in health care facilities. Ethnic and racial minorities faced disproportionate impacts. To minimize harm to patients with cerebrovascular disease in future public health crises, it is crucial to develop policies that address these findings.

Surface distortion of FeRu nanoparticles improves the hydrogen evolution reaction performance in alkaline media.

Rational design of electrocatalysts, including an increased catalytic surface area, a unique surface structure, and improved conductivity, for facilitating the hydrogen evolution reaction (HER) is emerging as an important issue. In this work, we consider the engineering of catalyst surfaces as an effective and feasible way to accelerate the HER kinetics. By etching the surface Fe of FeRu alloy nanoparticles (NPs) using hydrofluoric acid (HF), a distorted catalytic surface of FeRu NPs was formed. The distorted surface of the HF-treated FeRu NPs was successfully analyzed by X-ray absorption spectroscopy, high-resolution photoemission spectroscopy, and electrochemical absorption/desorption experiments. The electrocatalytic HER activity of the HF-treated FeRu NPs demonstrated that surface distortion enhances the water dissociation reaction and the electron transfer rate. As a result, the surface-distorted FeRu NPs improved HER performances in alkaline media compared to the pristine FeRu alloy NP/C, commercial Ru/C, and the state-of-the-art Pt/C catalysts.

Revealing Photocatalytic Performance of ZnxCd1-xS Nanoparticles Depending on the Irradiation Wavelength.

Photocatalysts are useful for various applications, including the conservation and storage of energy, wastewater treatment, air purification, semiconductors, and production of high-value-added products. Herein, ZnxCd1-xS nanoparticle (NP) photocatalysts with different concentrations of Zn2+ ions (x = 0.0, 0.3, 0.5, or 0.7) were successfully synthesized. The photocatalytic activities of ZnxCd1-xS NPs varied with the irradiation wavelength. X-ray diffraction, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and ultraviolet-visible spectroscopy were used to characterize the surface morphology and electronic properties of the ZnxCd1-xS NPs. In addition, in situ X-ray photoelectron spectroscopy was performed to investigate the effect of the concentration of Zn2+ ions on the irradiation wavelength for photocatalytic activity. Furthermore, wavelength-dependent photocatalytic degradation (PCD) activity of the ZnxCd1-xS NPs was investigated using biomass-derived 2,5-hydroxymethylfurfural (HMF). We observed that the selective oxidation of HMF using ZnxCd1-xS NPs resulted in the formation of 2,5-furandicarboxylic acid via 5-hydroxymethyl-2-furancarboxylic acid or 2,5-diformylfuran. The selective oxidation of HMF was dependent on the irradiation wavelength for PCD. Moreover, the irradiation wavelength for the PCD depended on the concentration of Zn2+ ions in the ZnxCd1-xS NPs.

Remote ischemic conditioning (RIC) with exercise (RICE) is safe and feasible for acute ischemic stroke (AIS) patients.

Objective: Rehabilitation is essential in reducing stroke disability and should be performed as early as possible. Exercise is an established and effective rehabilitation method; however, its implementation has been limited as its very early use exacerbates cerebral injury and is restricted by patients' unstable conditions and disabilities. Remote ischemic conditioning (RIC) is a passive and accessible therapy in acute phases of stroke and appears to have similar neuroprotective effects as exercise. This study assessed the safety and feasibility of the novel rehabilitation strategy-early RIC followed by exercise (RICE) in acute ischemic stroke (AIS). Methods: We conducted a single-center, double-blinded, randomized controlled trial with AIS patients within 24 h of stroke onset or symptom exacerbation. All enrolled patients were randomly assigned, at a ratio of 1:1, to either the RICE group or the sham-RICE group (sham RIC with exercise). Each group received either RIC or sham RIC within 24 h after stroke onset or symptom exacerbation, once a day, for 14 days. Both groups started the exercise routine on day 4, twice daily, for 11 total days. The safety endpoints included clinical deterioration, recurrence of stroke, hemorrhagic transformation, complications, and adverse events resulting from RICE during hospitalization. The efficacy endpoints [Modified Rankin Scale (mRS) score, National Institutes of Health Stroke Scale (NIHSS) score, Barthel Index, and walking ability] were evaluated at admission and 90 days after stroke onset. Results: Forty AIS patients were recruited and completed the study. No significant differences in baseline characteristics were found between the two groups, which included risk factors, stroke severity at admission, pre-morbid disability, and other special treatments. No significant differences were found in the safety endpoints between two groups. Excellent recovery (mRS 0-2) at 3 months was obtained in 55% of the patients with RICE as compared 40% in sham group, but it did not reach a significant level. Conclusions: RICE was safe and feasible for AIS patients, and seems to be a promising early stroke rehabilitation. The results of this study suggest a need for a future randomized and controlled multicenter trial with a larger sample size to determine the efficacy of RICE.

Selective Oxidation of Biomass Molecules via ZnO Nanoparticles Modified Using Charge Mismatch of the Doped Co ions.

A charge mismatch between transition-metal-ion dopants and metal oxide nanoparticles (MO NPs) within an engineered complex engenders a significant number of oxygen vacancies (VO) on the surface of the MO NP construct. To elucidate in-depth the mechanism of this tendency, Co ions with different charge states (Co3+ and Co2+) were doped into ZnO NPs, and their atomic structural changes were correlated with their photocatalytic efficiency. We ascertained that the increase of the Zn-O bond distances was distinctly affected by Co3+-ion doping, and, subsequently, the number of VO was noticeably increased. We further investigated the mechanistic pathways of the photocatalytic oxidation of 2,5-hydroxymethylfurfural (HMF), which have been widely investigated as biomass derivatives because of their potential use as precursors for the synthesis of sustainable alternatives to petrochemical substances. To identify the reaction products in each oxidation step, selective oxidation products obtained from HMF in the presence of pristine ZnO NPs, Co3+- and Co2+-ion-doped ZnO NPs were evaluated. We confirmed that Co3+-ion-doped ZnO NPs can efficiently and selectively oxidize HMF with a good conversion rate (∼40%) by converting HMF to 2,5-furandicarboxylic acid (FDCA). The present study demonstrates the feasibility of improving the production efficiency of FDCA (an alternative energy material) by using enhanced photocatalytic MO NPs with the help of the charge mismatch between MO and metal-ion dopants.

Inflammation and Severe Cerebral Venous Thrombosis.

Cerebral venous thrombosis (CVT) is a rare type of venous thromboembolism (VTE). It is an important cause of stroke in young adults and children. Severe CVT, which is characterized by cerebral venous infarction or hemorrhage, seizures, or disturbance of consciousness, has more severe clinical manifestations and a worse prognosis. It is commonly believed that the onset of severe CVT gave credit to venous return disorder, with the underlying pathogenesis remaining unclear. There is increasing evidence suggesting that an inflammatory response is closely associated with the pathophysiology of severe CVT. Preclinical studies have identified the components of neuroinflammation, including microglia, astrocytes, and neutrophils. After CVT occurrence, microglia are activated and secrete cytokines (e.g., interleukin-1ß and tumor necrosis factor-α), which result in a series of brain injuries, including blood-brain barrier disruption, brain edema, and cerebral venous infarction. Additionally, astrocytes are activated at the initial CVT stage and may interact with microglia to exacerbate the inflammatory response. The extent of cerebral edema and neutrophil recruitment increases temporally in the acute phase. Further, there are also changes in the morphology of inflammatory cells, expression of inflammatory mediators, and inflammatory pathway molecules with CVT progression. Lately, some clinical research suggested that some inflammation-related biomarkers are of great value in assessing the course, severity, and prognosis of severe CVT. Moreover, basic and clinical research suggested that anti-inflammatory therapy might hold promise in severe CVT. This study reviews the current literature regarding the involvement of inflammation in the pathophysiology and anti-inflammatory interventions of severe CVT, which would contribute to informing the pathophysiology mechanism and laying a foundation for exploring novel severe CVT therapeutic strategies.