Direct conversion of methane to aromatics and hydrogen via a heterogeneous trimetallic synergistic catalyst.

Non-oxidative methane dehydro-aromatization reaction can co-produce hydrogen and benzene effectively on a molybdenum-zeolite based thermochemical catalyst, which is a very promising approach for natural-gas upgrading. However, the low methane conversion and aromatics selectivity and weak durability restrain the realistic application for industry. Here, a mechanism for enhancing catalysis activity on methane activation and carbon-carbon bond coupling has been found to promote conversion and selectivity simultaneously by adding platinum-bismuth alloy cluster to form a trimetallic catalyst on zeolite (Pt-Bi/Mo/ZSM-5). This bimetallic alloy cluster has synergistic interaction with molybdenum: the formed CH3* from Mo2C on the external surface of zeolite can efficiently move on for C-C coupling on the surface of Pt-Bi particle to produce C2 compounds, which are the key intermediates of oligomerization. This pathway is parallel with the catalysis on Mo inside the cage. This catalyst demonstrated 18.7% methane conversion and 69.4% benzene selectivity at 710 °C. With 95% methane/5% nitrogen feedstock, it exhibited robust stability with slow deactivation rate of 9.3% after 2 h and instant recovery of 98.6% activity after regeneration in hydrogen. The enhanced catalytic activity is strongly associated with synergistic interaction with Mo and ligand effects of alloys by extensive mechanism studies and DFT calculation.

Association between cognitive impairment and olfactory deficits in systemic lupus erythematosus without major neuropsychiatric syndromes.

OBJECTIVE: The aim of the study was to investigate the utility of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), evaluate cognitive deficits in systemic lupus erythematosus (SLE) patients and examine the relationship between cognitive and olfactory functions. METHODS: 55 SLE patients and 50 healthy controls were administered by RBANS including five indexes: immediate memory (IMME), visuospatial/constructional (Vis/Con), language (LANG), attention (ATT), and delayed memory (DEME). Olfactory functions were evaluated by computerized testing including three stages of smell: threshold (THR), identification (ID), and memory (ME) of different odors. The disease activity and cumulative damage were assessed by the SLE Disease Activity Index 2000 (SLEDAI-2K) and the Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology (ACR) Damage Index (SDI). RESULTS: SLE patients exhibited significant lower total RBANS scores, IMME, Vis/Con, ATT, and DEME index scores than healthy controls (p < 0.01 for all and p = 0.027 for attention). Reduced RBANS scores were associated with several organ involvement and autoantibodies. SLE patients with higher SLEDAI-2K scores or with accumulated damage (SDI≥1) showed decreased RBANS scores. All the olfactory scores in SLE patients were significantly decreased than controls (p = 0.001). Patients had higher proportion of anosmia (8.57% vs 0%) and hyposmia (28.58% vs 5.72%) than controls (χ2 = 10.533, p = 0.015). Multivariable regression analysis revealed that olfactory functions had a positive effect on RBANS index scores. Olfactory memory and total scores were significantly correlated with the DEME (r = 0.393, p = 0.021) and total scores (r = 0.429, p = 0.011). CONCLUSION: This study indicates that significantly cognitive and olfactory functions are impaired in SLE patients. The RBANS is a potentially useful instrument for evaluating neuropsychological status in SLE. Physicians are encouraged to perform routine screening in SLE patients to detect subtle cognitive dysfunction.

Root Cause Analysis of Degradation in Protonic Ceramic Electrochemical Cell with Interfacial Electrical Sensors Using Data-Driven Machine Learning.

Protonic ceramic electrochemical cells (PCECs) offer promising paths for energy storage and conversion. Despite considerable achievements made, PCECs still face challenges such as physiochemical compatibility between componenets and suboptimal solid-solid contact at the interfaces between the electrolytes and electrodes. In this study, a novel approach is proposed that combines in situ electrochemical characterization of interfacial electrical sensor embedded PCECs and machine learning to quantify the contributions of different cell components to total degradation, as well as to predict the remaining useful life. The experimental results suggest that the overpotential induced by the oxygen electrode is 48% less than that of oxygen electrode/electrolyte interfacial contact for up to 1171 h. The data-driven machine learning simulation predicts the RUL of up to 2132 h. The root cause of degradation is overpotential increase induced by oxygen electrode, which accounts for 82.9% of total cell degradation. The success of the failure diagnostic model is demonstrated by its consistency with degradation modes that do not manifest in electrolysis fade during early real operations. This synergistic approach provides valuable insights into practical failure diagnosis of PCECs and has the potential to revolutionize their development by enabling improved performance prediction and material selection for enhanced durability and efficiency.

Mathematical Model-Assisted Ultrasonic Spray Coating for Scalable Production of Large-Sized Solid Oxide Electrochemical Cells.

Thin solid oxide films are crucial for developing high-performance solid oxide-based electrochemical devices aimed at decarbonizing the global energy system. Among various methods, ultrasonic spray coating (USC) can provide the throughput, scalability, quality consistency, roll-to-roll compatibility, and low material waste necessary for scalable production of large-sized solid oxide electrochemical cells. However, due to the large number of USC parameters, systematic parameter optimization is required to ensure optimal settings. However, the optimizations in previous literature are either not discussed or not systematic, facile, and practical for scalable production of thin oxide films. In this regard, we propose an USC optimization process assisted with mathematical models. Using this method, we obtained optimal settings for producing high-quality, uniform 4 × 4 cm2 oxygen electrode films with a consistent thickness of ∼27 µm in 1 min in a facile and systematic way. The quality of the films is evaluated at both micrometer and centimeter scales and meets desirable thickness and uniformity criteria. To validate the performance of USC-fabricated electrolytes and oxygen electrodes, we employ protonic ceramic electrochemical cells, which achieve a peak power density of 0.88 W cm-2 in the fuel cell mode and a current density of 1.36 A cm-2 at 1.3 V in the electrolysis mode, with minimal degradation over a period of 200 h. These results demonstrate the potential of USC as a promising technology for scalable production of large-sized solid oxide electrochemical cells.

Adeno-Associated Virus-Mediated Immunotherapy Based on Bispecific Tandem scFv for Alzheimer's Disease.

BACKGROUND: Patients with Alzheimer's disease (AD) have considerably increased globally as a result of population aging, placing a significant burden on the global economy and the medical system. The outcome of clinical trials for AD immunotherapy that solely targeted amyloid-ß (Aß) or phosphorylated tau protein (p-Tau) was unsatisfactory. Therefore, blocking both Aß and p-Tau's pathological processes simultaneously while also preventing their interaction may be the key to developing an effective AD therapy. OBJECTIVE: To develop a novel immunotherapy based on bispecific tandem scFv (TaFv) against AD. METHODS: Bispecific single-chain antibody that targets both Aß and p-Tau were obtained using E. coli expression system. Biological ability of TaFvs were determined by ELISA, SDS-PAGE, and immunohistochemical assay. Recombinant adeno-associated virus 9 (rAAV9) were packaged to create TaFv. The in vivo activity of rAAV9 were detected in mouse, using biophotonic imaging and frozen section methods. RESULTS: The outcomes demonstrated that both Aß and p-Tau had a high affinity for the bispecific TaFv. Additionally, it can bind to the amyloid plaques and neuronal tangles in the brain slices of an AD mouse model. Moreover, the rAAV9 could infect neuronal cells, transverse the blood-brain barrier, and express TaFv in the mouse brain. CONCLUSION: This novel immunotherapy offers a fresh concept for the immunotherapy of AD and successfully delivers the double target antibody into the brain, acting on both pathogenic substances Aß and p-Tau.

An Unbalanced Battle in Excellence: Revealing Effect of Ni/Co Occupancy on Water Splitting and Oxygen Reduction Reactions in Triple-Conducting Oxides for Protonic Ceramic Electrochemical Cells.

Porous electrodes that conduct electrons, protons, and oxygen ions with dramatically expanded catalytic active sites can replace conventional electrodes with sluggish kinetics in protonic ceramic electrochemical cells. In this work, a strategy is utilized to promote triple conduction by facilitating proton conduction in praseodymium cobaltite perovskite through engineering non-equivalent B-site Ni/Co occupancy. Surface infrared spectroscopy is used to study the dehydration behavior, which proves the existence of protons in the perovskite lattice. The proton mobility and proton stability are investigated by hydrogen/deuterium (H/D) isotope exchange and temperature-programmed desorption. It is observed that the increased nickel replacement on the B-site has a positive impact on proton defect stability, catalytic activity, and electrochemical performance. This doping strategy is demonstrated to be a promising pathway to increase catalytic activity toward the oxygen reduction and water splitting reactions. The chosen PrNi0.7 Co0.3 O3- δ oxygen electrode demonstrates excellent full-cell performance with high electrolysis current density of -1.48 A cm-2 at 1.3 V and a peak fuel-cell power density of 0.95 W cm-2 at 600 °C and also enables lower-temperature operations down to 350 °C, and superior long-term durability.

Revitalizing interface in protonic ceramic cells by acid etch.

Protonic ceramic electrochemical cells hold promise for operation below 600 °C (refs. 1,2). Although the high proton conductivity of the bulk electrolyte has been demonstrated, it cannot be fully used in electrochemical full cells because of unknown causes3. Here we show that these problems arise from poor contacts between the low-temperature processed oxygen electrode-electrolyte interface. We demonstrate that a simple acid treatment can effectively rejuvenate the high-temperature annealed electrolyte surface, resulting in reactive bonding between the oxygen electrode and the electrolyte and improved electrochemical performance and stability. This enables exceptional protonic ceramic fuel-cell performance down to 350 °C, with peak power densities of 1.6 W cm-2 at 600 °C, 650 mW cm-2 at 450 °C and 300 mW cm-2 at 350 °C, as well as stable electrolysis operations with current densities above 3.9 A cm-2 at 1.4 V and 600 °C. Our work highlights the critical role of interfacial engineering in ceramic electrochemical devices and offers new understanding and practices for sustainable energy infrastructures.

Self-sustainable protonic ceramic electrochemical cells using a triple conducting electrode for hydrogen and power production.

The protonic ceramic electrochemical cell (PCEC) is an emerging and attractive technology that converts energy between power and hydrogen using solid oxide proton conductors at intermediate temperatures. To achieve efficient electrochemical hydrogen and power production with stable operation, highly robust and durable electrodes are urgently desired to facilitate water oxidation and oxygen reduction reactions, which are the critical steps for both electrolysis and fuel cell operation, especially at reduced temperatures. In this study, a triple conducting oxide of PrNi0.5Co0.5O3-δ perovskite is developed as an oxygen electrode, presenting superior electrochemical performance at 400~600 °C. More importantly, the self-sustainable and reversible operation is successfully demonstrated by converting the generated hydrogen in electrolysis mode to electricity without any hydrogen addition. The excellent electrocatalytic activity is attributed to the considerable proton conduction, as confirmed by hydrogen permeation experiment, remarkable hydration behavior and computations.

Direct Identification of Surface Defects and Their Influence on the Optical Characteristics of Upconversion Nanoparticles.

Core-shell structure is an obvious concept to suppress surface-related deactivations in lanthanide-doped upconversion nanoparticles (UCNPs). However, no direct observation of atomic-scale surface restoration, which can improve the upconversion photoluminescence, has been reported. Here, we use aberration-corrected high-angle annular dark field scanning transmission electron microscopy to study the surface condition of KLu2F7:Yb3+,Er3+ bare core UCNPs. Due to the very thin and uniform thickness of the UCNPs, we observe unambiguously that the recovery from surface defects enhances upconversion photoluminescence. Furthermore, the realization of dominant green lasing emission under pulsed laser excitation confirms the high crystallinity of the UCNPs.

Improved Near-Infrared Up-Conversion Emission of Tm3+ Sensitized by Yb3+ and Ho3+ in LuF3 Nanocrystals.

In the present work, mono-disperse and uniform orthorhombic lutetium fluoride (LuF3) nanocrystals with an average size of about 35 nm have been successfully synthesized by a simple ionothermal method without any template. The infrared (IR) to visible up-conversion (UC) photoluminescence of LuF3 doped with Yb3+, Tm3+, and Ho3+ under 980 nm excitation was systemically studied. The intensity of near infrared (NIR) to visible up-conversion emission of Tm3+ was improved efficiently by adding Yb3+ and Ho3+ in LuF3, especially for the broad NIR emission band located at 812 nm. Meanwhile, compared to the Yb3+ and Tm3+ co-doped LuF3, the ratio of red to green emission in the Yb3+, TmS+, and HoS+ co-doped LuF3 changed greatly, and a bright yellowish-green emission was observed under 980 nm laser excitation. It shows that Yb3+, Tm3+ and Ho3+ co-doped LuF3 nanocrystals provided a potential application in vitro and in vivo bio-imaging, color displays and optical storage.

The intermediate products in the degradation of 4-chlorophenol by pulsed high voltage discharge in water.

Degradation of 4-chlorophenol by pulsed high voltage discharge is an intricate process involving a series of complex chemical reactions. Hydroxylation of 4-chlorophenol to form hydroquinone, 4-chlororesorcinol and 4-chlorocatechol is the first step, though a very small amount of direct cleavage products of the C(1)-C(2) or C(5)-C(6) bond are observed. The yield of 4-chlorocatechol is about twice as much as that of hydroquinone. Less 4-chloresorcinol is produced. The free chloride ions dropped from the 4-chlorophenol degradation can obtain reactivity again from the discharge, and react with undegraded 4-chlorophenol to form 2,4-dichlorophenol. Some ring-opened products have also been identified and their possible reaction routes are proposed. Several compounds are verified by use of authentic samples. The more stable ring-opened products are low molecular weight (LMW) acids such as formic, acetic, oxalic, malonate, maleic and malic acid. By discharging 4-chlorophenol aqueous solution for 36 min, the amount of carbons obtained from organic acids is more than 50% while that of carbons from aromatic products less than 20% in the carbons of degraded 4-chlorophenol, which is about 94% of initial carbons. After 60 min of discharge, all the 4-chlorophenol and its aromatic intermediates have been removed completely and the organic carbons are mainly presented as organic acid such as acetic and oxalate acid. At the end of the 120 min discharge, the amount of the remaining organic carbons is not more than 14% of the initial carbons.

Organic contaminants removal by the technique of pulsed high-voltage discharge in water.

Pulsed high-voltage discharge as one of the AOTs has generated a lot of interest in its applications to organic contaminants removal. It was demonstrated that some contaminants such as dyes and phenols could be effectively removed by the discharge, which can promote both physical and chemical processes leading to strong UV light, local high temperature, intense shock waves and the formation of chemically active species such as OH, H, O, O(2)(-), HO(2), H(2)O(2), O(3), respectively, etc. The technology was been further developed by the updating of the power supply and the discharge reactor. The formation of active species is one of the crucial factors in the degradation of organic compounds in the pulsed high-voltage discharge system. This paper reviews the literatures on the pulsed power supply, reactor, physical effects, active species formation and mechanism of organic contaminants degradation in the discharge system.

4-Chlorophenol degradation by pulsed high voltage discharge coupling internal electrolysis.

A system of pulsed high voltage discharge coupling internal electrolysis (PHVDCIE) in water has been developed to remove 4-chlorophenol (4-CP). The hydrogen peroxide formed by discharge was little utilized by 4-CP degradation in the sole discharge system, but most of the hydrogen peroxide could be utilized in the PHVDCIE system to form hydroxyl radicals for the production of Fe(2+). The Fe(2+) was generated in the cell reaction and was reacted with the hydrogen peroxide through the Fenton's reaction. The formation rate of hydroxyl radical was increased in the PHVDCIE system. It was 5.28 x 10(-7)mol L(-1)s(-1) with bubbling oxygen but it was 1.49 x 10(-7)mol L(-1)s(-1) in the sole discharge system. With increase in the yields of hydroxyl radical, the 4-CP removal was sped up. The removal efficiency of 4-CP was improved to more than 90% correspondingly by 36 min discharge in the PHVDCIE system. With the promotion of 4-CP degradation, more intermediate products such as formic, acetic and oxalic acid were produced.

Enhanced degradation of p-chlorophenol in a novel pulsed high voltage discharge reactor.

The yields of active specie such as ozone, hydrogen peroxide and hydroxyl radical were all enhanced in a novel discharge reactor. In the reactor, the original formation rate of hydroxyl radical was 2.27 x 10(-7) mol L(-1)s(-1), which was about three times than that in the contrast reactor. Ozone was formed in gas-phase and was transferred into the liquid. The characteristic of mass transfer was better in the novel reactor than that in the contrast reactor, which caused much higher ozone concentration in liquid. The dissociation of hydrogen peroxide was more evident in the former, which promoted the formations of hydroxyl radical. The p-chlorophenol (4-CP) degradation was also enhanced. Most of the ozone transferred into the liquid and hydrogen peroxide generated by discharge could be utilized by the degradation process of 4-CP. About 97% 4-CP was removed in 36 min discharge in the novel reactor. Organic acids such as formic, acetic, oxalic, propanoic and maleic acid were generated and free chloride ions were released in the degradation process. With the formation of organic acid, the pH was decreased and the conductivity was increased.

An electrohydraulic discharge system of salt-resistance for p-chlorophenol degradation.

An electrohydraulic discharge system of salt-resistance has been developed and analyzed for p-chlorophenol (4-CP) degradation. The discharge electrodes used in the system was consisted of four steel acupuncture needles (Ø 0.25 mm) which were covered by capillaries through which gas was supplied to the discharge region, forming gas bubbles. In the comparing system, the aeration capillaries were encapsulated and the bubbling was cancelled. It was confirmed that introducing gas into the discharge zone could reduce the affection of salt content in the pulsed high-voltage electrohydraulic discharge system. In the non-bubbling system, the formation of active species and 4-CP degradation was sharply influenced by increasing salt content. The formation rate of hydroxyl radical and hydrogen peroxide was decreased almost to zero and the 4-CP was hardly removed as the NaCl concentration was higher than 5.0 x 10(-3) mol L(-1). But in the developed system, the formation rates were changed little with increasing the salt concentration. Increasing the NaCl concentration high to 0.1 mol L(-1), the hydroxyl radical formation rate was 4.43 x 10(-7) mol L(-1)s(-1), and the removal rate of 4-CP was still high, where more than 90% was removed in 18 min.

Degradation of 4-CP in an internal electrolysis system.

The characteristic and mechanism of parachlorophenol (4-CP) degradation in an internal electrolysis system were investigated. The degradation rate of 4-CP was higher in acid solution than that of in neutral or alkaline solution. Addition of activated carbon could make 4-CP easier be degraded by the surface contact catalysis. The dissolved oxygen in solution could take part in the electrode reaction and intensify the degradation of 4-CP. By the analysis of intermediates of degradation of 4-CP, it could be conferred that 4-CP was broken through the bond beside hydroxy firstly, then the bond beside chloride was broken and the chloride was dechlorinated simultaneously. Most intermediate products were glycerine, ethane diacid and acetic acid, while very few 1,4-butanedial and alcohols were found.