Cardiovascular and Cancer Risk with Tofacitinib in Rheumatoid Arthritis.

BACKGROUND: Increases in lipid levels and cancers with tofacitinib prompted a trial of major adverse cardiovascular events (MACE) and cancers in patients with rheumatoid arthritis receiving tofacitinib as compared with a tumor necrosis factor (TNF) inhibitor. METHODS: We conducted a randomized, open-label, noninferiority, postauthorization, safety end-point trial involving patients with active rheumatoid arthritis despite methotrexate treatment who were 50 years of age or older and had at least one additional cardiovascular risk factor. Patients were randomly assigned in a 1:1:1 ratio to receive tofacitinib at a dose of 5 mg or 10 mg twice daily or a TNF inhibitor. The coprimary end points were adjudicated MACE and cancers, excluding nonmelanoma skin cancer. The noninferiority of tofacitinib would be shown if the upper boundary of the two-sided 95% confidence interval for the hazard ratio was less than 1.8 for the combined tofacitinib doses as compared with a TNF inhibitor. RESULTS: A total of 1455 patients received tofacitinib at a dose of 5 mg twice daily, 1456 received tofacitinib at a dose of 10 mg twice daily, and 1451 received a TNF inhibitor. During a median follow-up of 4.0 years, the incidences of MACE and cancer were higher with the combined tofacitinib doses (3.4% [98 patients] and 4.2% [122 patients], respectively) than with a TNF inhibitor (2.5% [37 patients] and 2.9% [42 patients]). The hazard ratios were 1.33 (95% confidence interval [CI], 0.91 to 1.94) for MACE and 1.48 (95% CI, 1.04 to 2.09) for cancers; the noninferiority of tofacitinib was not shown. The incidences of adjudicated opportunistic infections (including herpes zoster and tuberculosis), all herpes zoster (nonserious and serious), and adjudicated nonmelanoma skin cancer were higher with tofacitinib than with a TNF inhibitor. Efficacy was similar in all three groups, with improvements from month 2 that were sustained through trial completion. CONCLUSIONS: In this trial comparing the combined tofacitinib doses with a TNF inhibitor in a cardiovascular risk-enriched population, risks of MACE and cancers were higher with tofacitinib and did not meet noninferiority criteria. Several adverse events were more common with tofacitinib. (Funded by Pfizer; ORAL Surveillance ClinicalTrials.gov number, NCT02092467.).

Atomic Strain Wave-Featured LaRuIr Nanocrystals: Achieving Simultaneous Enhancement of Catalytic Activity and Stability toward Acidic Water Splitting.

Rare earth microalloying nanocrystals have gotten widespread attention due to their unprecedented performances with customization-defected nanostructures, divided energy bands, and ensembled surface chemistry, regarded as a class of ideal electrocatalysts for oxygen evolution reaction (OER). Herein, a lanthanide microalloying strategy is proposed to fabricate strain wave-featured LaRuIr nanocrystals with oxide skin through a rapid crystal nucleation, using thermally assisted sodium borohydride reduction in aqueous solution at 60 °C. The atomic strain waves with alternating compressive and tensile strains, resulting from La-stabilized edge dislocations in form of Cottrell atmospheres. In 0.5 m H2SO4, the LaRuIr displays an overpotential of 184 mV at 10 mA cm-2, running at a steadily cell voltage for 60 h at 50 mA cm-2, eightfold enhancement of IrO2||Pt/C assemble in PEMWE. The coupled compressive and tensile profiles boost the OER kinetics via faster AEM and LOM pathways. Moreover, the tensile facilitates surface structure stabilization through dynamic refilling of lattice oxygen vacancies by the adsorbed oxyanions on La, Ru, and Ir sites, eventually achieving a long-term stability. This work contributes to developing advanced catalysts with unique strain to realize simultaneous improvement of activity and durability by breaking the so-called seesaw relationship between them during OER for water splitting.

Nest-Scheme RuIrLa Nanocrystals by NP-to-NP Oriented Assembly: Coherent Strain Fields-Driven Band Structure Splitting for Efficient Acidic Water Oxidation.

Atomic substructure engineering provides new opportunities for the designing newly and efficient catalysts with diverse atom ensembles, trimmed electron bands, and way-out coordination environments, creating unique contributing to concertedly catalyze water oxidation, which is of great significance for proton exchange membrane water electrolysis (PEMWE). Herein, nest-scheme RuIrLa nanocrystals with dense coherent interfaces as built-in substructures are firstly fabricated by using commercial ZnO particles as acid-removable templates, through a La-stabilized coherent epitaxial growth of nanoparticles (NPs). The obtained nests exhibit a low overpotential of 198 mV at 10 mA cm-2, and the RuIrLa||Pt/C module equipped in PEMWE operates stably at a cell voltage potential of 1.69 V at 100 mA cm-2 in 0.5 M H2SO4 for 55 h, which is far beyond the current IrO2||Pt/C. Within the nests, the position at the interface shows high tensile/compressive strain, significantly reducing the OER activation energy. More importantly, the La termination-stabilized coherent interfaces within the nests creates a unique self-healing process for the outstanding long-term stability. This work provides a promising substructure engineering to develop efficient catalysts with abundant substructures, such as coherent interfaces, dislocations, or grain boundaries, thereby realizing concerted improvement of activity and durability toward water oxidation.

Rapid Conversion from Alloy Nanoparticles to Oxide Nanowires: Strain Wave-Driven Ru-O-Mn Collaborative Catalysis for Durable Oxygen Evolution Reaction.

Metal-doped ruthenium oxides with low prices have gained widespread attention due to their editable compositions, distorted structures, and diverse morphologies for electrocatalysis. However, the mainstream challenge lies in breaking the so-called seesaw relationship between activity and stability during acidic oxygen evolution reaction (OER). Herein, strain wave-featured Mn-RuO2 nanowires (NWs) with asymmetric Ru-O-Mn bonds are first fabricated by thermally driven rapid solid phase conversion from RuMn alloy nanoparticles (NPs) at moderate temperature (450 °C). In 0.5 M H2SO4, the resultant NWs display a surprisingly ultralow overpotential of 168 mV at 10 mA cm-2 and run at a stable cell voltage (1.67 V) for 150 h at 50 mA cm-2 in PEMWE, far exceeding IrO2||Pt/C assemble. The simultaneous enhancement of both activity and stability stems from the presence of dense strain waves composed of alternating compressive and tensile ones in the distorted NWs, which collaboratively activate the Ru-O-Mn sites for faster OER. More importantly, the atomic strain waves trigger dynamic Ru-O-Mn regeneration via the refilling of oxygen vacancies by oxyanions adsorbed on adjacent Mn and Ru sites, achieving long-term stability. This work opens a door to designing non-precious metal-assisted ruthenium oxides with unique strains for practical application in commercial PEMWE.

Periodic DFT calculations for the heterogeneous formation of 2-chlorothiophenoxy radical from 2-chlorothiophenol on Cu(111) surface in fly ash.

Copper plays a crucial role in the heterogenous dissociation of chlorothiophenols (CTPs) to form chlorothiophenoxy radicals (CTPRs), which is the initial and critical step in the formation of polychlorinated thianthrenes/dibenzothiophenes (PCTA/DTs). Here, first-principles calculations were performed to investigate the activity of Cu(111) surface towards the formation of adsorbed 2-CTPR from 2-CTP. The interaction between 2-CTP and Cu(111) surface was explored to find stable adsorption configurations. Besides, the decomposition routes of 2-CTP on the Cu(111) surface were further explored. Moreover, the effects of water on the formation of absorbed 2-CTPR on the Cu(111) surface were examined. Our results demonstrate that the flat adsorption of 2-CTP on the surface with adsorption energy in the range of -33.21 kcal/mol to -28.37 kcal/mol is more stable than the vertical adsorption with adsorption energy ranging from -23.53 kcal/mol to -13.38 kcal/mol. The Cu(111) surface catalyzes the conversion of 2-CTP into the adsorbed 2-CTPR with a modest energy barrier of 9.46 kcal/mol. Furthermore, water molecules exhibit stronger catalytic activity in this process with a decreased energy barrier of 5.87 kcal/mol through "water bridge" and hydrogen bonding. Specifically, the water accepts the hydrogen atom from 2-CTP and donates another hydrogen to the surface via "water bridge". This research provides a molecular-level understanding of the heterogeneous formation of PCTA/DTs by fly ash, suggesting novel approaches for control strategy and legislation of dioxin analogues.

Enhanced NO2 Gas Sensing Properties Based on Rb-Doped ZnO/In2O3 Heterojunctions at Room Temperature: A Combined DFT and Experimental Study.

In this work, alkali metal Rb-loaded ZnO/In2O3 heterojunctions were synthesized using a combination of hydrothermal and impregnation methods. The morphology and structure of the synthesized samples were characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. The enhancement mechanism of the nitrogen dioxide gas sensing performance of the Rb-loaded ZnO/In2O3 heterojunctions was systematically investigated at room temperature using density-functional theory calculations and experimental validation. The experimental tests showed that the Rb-loaded ZnO/In2O3 sensor achieved an excellent response value of 24.2 for 1 ppm NO2, with response and recovery times of 55 and 21 s, respectively. This result is 20 times higher than that of pure ZnO sensors and two times higher than that of ZnO/In2O3 sensors, indicating that the Rb-loaded ZnO/In2O3 sensor has a more pronounced enhancement in performance for NO2. This study not only revealed the mechanism by which Rb loading affects the electronic structure and gas molecule adsorption behavior on the surface of ZnO/In2O3 heterojunctions but also provides theoretical guidance and technical support for the development of high-performance room-temperature NO2 sensors.

Rimegepant orally disintegrating tablet 75 mg for acute treatment of migraine in adults from China: a subgroup analysis of a double-blind, randomized, placebo-controlled, phase 3 clinical trial.

BACKGROUND: Rimegepant orally disintegrating tablet (ODT), an oral small-molecule calcitonin gene-related peptide receptor antagonist, is indicated for acute and preventive treatment of migraine in the United States and other countries. Previously, a large clinical trial assessed the efficacy and safety of rimegepant ODT 75 mg for the acute treatment of migraine in adults living in China or South Korea. A post hoc subgroup analysis of this trial was performed to evaluate the efficacy and safety of rimegepant for acute treatment of migraine in adults living in China. METHODS: Eligible participants were ≥ 18 years of age and had a ≥ 1-year history of migraine, with 2 to 8 attacks of moderate or severe pain intensity per month and < 15 headache days per month during the 3 months before screening. Participants self-administered rimegepant ODT 75 mg or matching placebo to treat a single migraine attack of moderate or severe pain intensity. The co-primary endpoints were pain freedom and freedom from the most bothersome symptom (MBS) at 2 h post-dose. Key secondary endpoints included pain relief at 2 h post-dose, ability to function normally at 2 h post-dose, use of rescue medication within 24 h post-dose, and sustained pain freedom from 2 to 24 h and 2 to 48 h post-dose. All p values were nominal. Safety was assessed via treatment-emergent adverse events (TEAEs), electrocardiograms, vital signs, and routine laboratory tests. RESULTS: Overall, 1075 participants (rimegepant, n = 538; placebo, n = 537) were included in the subgroup analysis. Rimegepant was more effective than placebo for the co-primary endpoints of pain freedom (18.2% vs. 10.6%, p = 0.0004) and freedom from the MBS (48.0% vs. 31.8%, p <  0.0001), as well as all key secondary endpoints. The incidence of TEAEs was comparable between the rimegepant (15.2%) and placebo (16.4%) groups. No signal of drug-induced liver injury was observed, and no study drug-related serious TEAEs were reported in the rimegepant group. CONCLUSIONS: A single dose of rimegepant 75 mg rimegepant was effective for the acute treatment of migraine in adults living in China, with safety and tolerability similar to placebo. TRIAL REGISTRATION: Clinicaltrials.gov NCT04574362 Date registered: 2020-10-05.

Anchoring Cs+ Ions on Carbon Vacancies for Selective CO2 Electroreduction to CO at High Current Densities in Membrane Electrode Assembly Electrolyzers.

Electrolyte cations have been demonstrated to effectively enhance the rate and selectivity of the electrochemical CO2 reduction reaction (CO2RR), yet their implementation in electrolyte-free membrane electrode assembly (MEA) electrolyzer presents significant challenges. Herein, an anchored cation strategy that immobilizes Cs+ on carbon vacancies was designed and innovatively implemented in MEA electrolyzer, enabling highly efficient CO2 electroreduction over commercial silver catalyst. Our approach achieves a CO partial current density of approximately 500 mA cm-2 in the MEA electrolyzer, three-fold enhancement compared to pure Ag. In situ Raman and theoretical analyses, combined with machine learning potentials, reveal anchored Cs induces an electric field that significantly promotes the adsorption of *CO2 - intermediates through performing muti-point energy calculations on each structure. Furthermore, reduced adsorption of *OH intermediates effectively hampers competing hydrogen evolution reaction, as clarified by disk electrode experiments and density functional theory studies. Additionally, coupling our system with commercial polysilicon solar cells yields a notable solar-to-CO energy conversion efficiency of 8.3 %. This study opens a new avenue for developing effective cation-promoting strategy in MEA reactors for efficient CO2RR.

Impact of metacognition on attitudes toward epilepsy in medical students.

PURPOSE: This study evaluated medical students' knowledge and attitudes toward epilepsy and the influence of metacognition thereon. METHOD: Valid questionnaires were administered to medical students including undergraduate, professional postgraduate, and standardized residency training students (N = 503). The questionnaire had 4 parts: demographic information, knowledge of epilepsy, attitudes toward epilepsy, and metacognitive assessment. The Chinese Public Attitudes Toward Epilepsy scale and 30-Item Metacognition Questionnaire were used to assess attitudes and metacognition, respectively. RESULTS: Almost all participants had heard of epilepsy; 38.8% had witnessed a seizure and 25% were acquainted with a person with epilepsy. The proportion of correct answers to epilepsy-related knowledge ranged from 40.6% (Putting an object into the mouth of a person experiencing an epileptic seizure) to 97% (Convulsion is a symptom of epilepsy). However, knowledge of epilepsy was not able to affect attitudes toward epilepsy. Age, years of clinical experience, having witnessed a seizure, positive belief of worry, and need to control thinking were correlated with the different domains of attitude toward epilepsy. When participants were divided into 2 groups-i.e., those with high and low knowledge of epilepsy, participants in the former group who had a positive belief of worry or had not witnessed any seizures were more likely to have negative attitudes toward epilepsy. CONCLUSION: Medical students showed good awareness of the etiology and symptoms of epilepsy. Overall, attitudes toward epilepsy were negative. A positive belief of worry was associated with a more negative attitude toward epilepsy among respondents with greater knowledge of epilepsy.

The effects of the gas-liquid interface and gas phase on Cl/ClO radical interaction with water molecules.

In the marine boundary layer (MBL), chlorine (Cl) and chlorine monoxide (ClO) are powerful oxidants with high concentrations. The gas-liquid interface is also ubiquitous in the MBL as a favorable site for atmospheric reactions. Understanding the role of water in Cl/ClO radical chemistry is essential for predicting their behavior in the atmosphere and developing effective strategies for mitigating their harmful effects. However, the research studies on the system of Cl/ClO radicals on the surface of water droplets are still insufficient. In previous studies, we have found unique results related to the hydroxyl radical at the interface using ab initio molecular dynamics (AIMD). In this work, we have used AIMD to investigate interactions between Cl/ClO radicals and water molecules at the gas-liquid interface. Radical mobility, radial distribution functions, coordination, and population analyses were conducted to investigate the surface preference, bonding pattern, and track Cl/ClO radicals in the water droplets. In addition, density functional theory (DFT) analysis was conducted to compare the results at the gas-liquid interface with those in the gas phase. We found that Cl/ClO radicals tend to remain near the gas-liquid interface in water droplet systems and outside of water clusters in gas phase systems. The ClO radical can form O*-H and Cl-O bonds with water molecules; however, neither the O*-O hemibond nor the Cl-H bond was detected in all systems. Different dominant structures were obtained for ClO in the interface and gas phase. The ClO radical can be bonded to one water molecule from its oxygen side, (H2O)0-Cl-O*-(H2O)1 at the interface, or to two water molecules from the chlorine and oxygen sides, (H2O)1-Cl-O*-(H2O)1 in the gas phase. Meanwhile, the Cl radical can only form a dominant structure like Cl*-(H2O)1 at the gas-liquid interface by making a Cl*-O hemibond. Providing a thorough explanation of the Cl/ClO radical behavior at the gas-liquid interface, this study will improve our understanding of the MBL's oxidizing capacity and pollution causes.

Same Wavelength Noise Filtering via Quantum Orbital Angular Momentum Emission.

In laser active detection, detection performance is affected by optical noise, laser interference, and environmental background interference. Conventional methods to filter optical noise take advantage of the differences between signal and noise in wavelength and polarization. Due to the limitations of traditional methods in the physical dimension, noise cannot be completely filtered out. In this manuscript, a new method of noise filtering based on the spatial distribution difference between the quantum orbital angular momentum beam and the background noise is proposed. The use of beams containing quantum orbital angular momentum can make the signal light have a new physical dimension and enrich the information of emitted light. We conduct a complete theoretical analysis and provide a proof-of-principle experiment. The experimental results are in good agreement with the theoretical analysis results, and there is a signal-to-noise ratio improvement of more than five times in laser active detection. Our method meets the urgent needs of laser active detection and can be applied in the field of high-quality target detection.

Theoretical insights into the degradation mechanisms, kinetics and eco-toxicity of oxcarbazepine initiated by OH radicals in aqueous environments.

As an anticonvulsant, oxcarbazepine (OXC) has attracted considerable attention for its potential threat to aquatic organisms. Density functional theory has been used to study the mechanisms and kinetics of OXC degradation initiated by OH radicals in aqueous environment. A total of fourteen OH-addition pathways were investigated, and the addition to the C8 position of the right benzene ring was the most vulnerable pathway, resulting in the intermediate IM8. The H-abstraction reactions initiated by OH radicals were also explored, where the extraction site of the methylene group (C14) on the seven-member carbon heterocyclic ring was found to be the optimal path. The calculations show that the total rate constant of OXC with OH radicals is 9.47 × 109 (mol/L)-1sec-1, and the half-life time is 7.32 s at 298 K with the [·OH] of 10-11 mol/L. Moreover, the branch ratio values revealed that OH-addition (89.58%) shows more advantageous than H-abstraction (10.42%). To further understand the potential eco-toxicity of OXC and its transformation products to aquatic organisms, acute toxicity and chronic toxicity were evaluated using ECOSAR software. The toxicity assessment revealed that most degradation products such as OXC-2OH, OXC-4OH, OXC-1O-1OOH, and OXC-1OH' are innoxious to fish and daphnia. Conversely, green algae are more sensitive to these compounds. This study can provide an extensive investigation into the degradation of OXC by OH radicals and enrich the understanding of the aquatic oxidation processes of pharmaceuticals and personal care products (PPCPs).

Oxygen-plasma-assisted formaldehyde adsorption mechanism of SnO2electrospun fibers.

Chemisorbed oxygen acts a crucial role in the redox reaction of semiconductor gas sensors, and which is of great significance for improving gas sensing performance. In this study, an oxygen-plasma-assisted technology is presented to enhance the chemisorbed oxygen for improving the formaldehyde sensing performance of SnO2electropun fiber. An inductively coupled plasma device was used for oxygen plasma treatment of SnO2electrospun fibers. The surface of SnO2electrospun fibers was bombarded with high-energy oxygen plasma for facilitating the chemisorption of electronegative oxygen molecules on the SnO2(110) surface to obtain an oxygen-rich structure. Oxygen-plasma-assisted SnO2electrospun fibers exhibited excellent formaldehyde sensing performance. The formaldehyde adsorption mechanism of oxygen-rich SnO2was investigated using density functional theory. After oxygen plasma modification, the adsorption energy and the charge transfer number of formaldehyde to SnO2were increased significantly. And an unoccupied electronic state appeared in the SnO2band structure, which could enhance the formaldehyde adsorption ability of SnO2. The gas sensing test revealed that plasma-treated SnO2electrospun fibers exhibited excellent gas sensing properties to formaldehyde, low operating temperature, high response sensitivity, and considerable cross-selectivity. Thus, plasma modification is a simple and effective method to improve the gas sensing performance of sensors.

The Homogeneous Gas-Phase Formation Mechanism of PCNs from Cross-Condensation of Phenoxy Radical with 2-CPR and 3-CPR: A Theoretical Mechanistic and Kinetic Study.

Chlorophenols (CPs) and phenol are abundant in thermal and combustion procedures, such as stack gas production, industrial incinerators, metal reclamation, etc., which are key precursors for the formation of polychlorinated naphthalenes (PCNs). CPs and phenol can react with H or OH radicals to form chlorophenoxy radicals (CPRs) and phenoxy radical (PhR). The self-condensation of CPRs or cross-condensation of PhR with CPRs is the initial and most important step for PCN formation. In this work, detailed thermodynamic and kinetic calculations were carried out to investigate the PCN formation mechanisms from PhR with 2-CPR/3-CPR. Several energetically advantageous formation pathways were obtained. The rate constants of key elementary steps were calculated over 600~1200 K using the canonical variational transition-state theory (CVT) with the small curvature tunneling (SCT) contribution method. The mechanisms were compared with the experimental observations and our previous works on the PCN formation from the self-condensation of 2-CPRs/3-CPRs. This study shows that naphthalene and 1-monochlorinated naphthalene (1-MCN) are the main PCN products from the cross-condensation of PhR with 2-CPR, and naphthalene and 2-monochlorinated naphthalene (2-MCN) are the main PCN products from the cross-condensation of PhR with 3-CPR. Pathways terminated with Cl elimination are preferred over those terminated with H elimination. PCN formation from the cross-condensation of PhR with 3-CPR can occur much easier than that from the cross-condensation of PhR with 2-CPR. This study, along with the study of PCN formation from the self-condensation 2-CPRs/3-CPRs, can provide reasonable explanations for the experimental observations that the formation potential of naphthalene is larger than that of 1-MCN using 2-CP as a precursor, and an almost equal yield of 1-MCN and 2-MCN can be produced with 3-CP as a precursor.

Role of thermal and non-thermal drying techniques on drying kinetics and the physicochemical properties of shiitake mushroom.

BACKGROUND: Fresh shiitake mushrooms are rich in nutrients, but have high water content, a fast metabolism after harvest, and deteriorate extremely easily. Therefore, the drying of shiitake mushrooms has become a research direction. However, the role of different drying techniques on shiitake mushroom quality is limited. Therefore, the purpose of this study was to investigate the effect of thermal and non-thermal drying on the drying kinetics, and the physicochemical properties of the end product. RESULTS: Results showed that shiitake mushroom treated with non-thermal drying (vacuum freeze-drying) had an attractive color, low shrinkage, and uniform honeycomb structure, while the drying time was the longest and not conducive to the formation of shiitake mushroom aroma. But shiitake mushroom treated with thermal drying presents an attractive fragrance. In thermal processing technology, compared with hot air convection drying (HAD), infrared hot air convection drying (IRHAD) shortens the drying time by 37.5%, and had the highest oxidation resistance, polysaccharide content and the lowest color change. Relative-humidity drying (RHD) samples had the lowest shrinkage compared with other thermal processing technology. The five polysaccharides exhibited similar preliminary structural characteristics, but the polysaccharides obtained by IRHAD have the highest antioxidant properties. CONCLUSION: These results showed that compared with thermal drying technology, non-thermal drying technology is not suitable for shiitake mushroom processing. In thermal processing technology, IRHAD is a potential drying method to obtain high-quality dried shiitake mushrooms and shiitake mushroom polysaccharide (SMP). However, it is necessary to increase the pretreatment technology to achieve the attractive appearance of non-thermal drying technology. © 2021 Society of Chemical Industry.

Effects of tri-frequency ultrasound-ethanol pretreatment combined with infrared convection drying on the quality properties and drying characteristics of scallion stalk.

BACKGROUND: Having short drying time and attractive product quality are important in fruit and vegetable dehydration processing. In this work, tri-frequency (20, 40 and 60 kHz) ultrasound-ethanol pretreatment, ultrasound-water pretreatment and ethanol pretreatment were employed before infrared convection drying (ICD) of scallion stalks, which was aimed at improving the drying process and quality of the end products. The mass transfer, drying characteristics (moisture ratio and drying rate and quality properties of scallion (rehydration, color, flavor, optical microscope image, moisture distribution and microbiological quality) were analyzed. RESULTS: All pretreatments have decreased the drying time by 33.34-83.34% compared to the control, while ultrasound-ethanol pretreatment provided the highest time reduction (83.34%). The reason is that the volatility of ethanol have replaced air in the tissue, which produced a better osmotic dehydration effect and the cavitation effect of ultrasound changed the cell function of the material, so that the food tissue was rapidly compressed and expanded, resulting in damage to the cell structure. Ultrasonic-ethanol pretreatment has greatly reduced the water loss and dry matter of fresh scallion, improved the rehydration effect of dried scallion, better retained the color and flavor of scallion and effectively reduced the microbiological quality of the scallion. CONCLUSION: The tri-frequency ultrasound-ethanol pretreatment has effectively improved the drying process and quality characteristics of the dried scallion. Therefore, this research has a great contribution to the drying technology, as evident in the remarkable reduction in drying time and the improvement in the quality of the end product. © 2020 Society of Chemical Industry.

Intensive pulsed light pretreatment combined with controlled temperature and humidity for convection drying to reduce browning and improve quality of dried shiitake mushrooms.

BACKGROUND: The change of surface color caused by browning during the drying process of shiitake mushrooms seriously affects its market circulation. Intensive pulsed light (IPL) as a non-heat-treatment method can reduce enzyme activity by changing the enzyme structure. Therefore, in this study, the use of IPL pretreatment before drying was aimed to reduce the adverse reactions caused by the browning reaction during the drying processing of shiitake mushrooms. RESULTS: Shiitake mushrooms pretreated with 25 pulses of IPL energy of 400 J reduced the initial polyphenol oxidase enzyme activity, the browning index, and browning degree values by 42.83%, 43.02%, and 47.54% respectively. The IPL pretreatment enhanced the polysaccharides and reducing sugars contents and it reduced 5-hydroxymethylfurfural generation in the dried shiitake mushrooms. The pretreatment also improved the surface color, the antioxidant activity, and retained the umami taste characteristics in the dried shiitake mushroom. CONCLUSION: The IPL pretreatment combined with controlled temperature and humidity for convection drying could be a suitable method to improve the quality of dried shiitake mushrooms. Therefore, this study provides a new pretreatment method for materials that are prone to browning during drying. © 2021 Society of Chemical Industry.

A Theoretical Study of Metalloporphyrin-Based Fluorescent Array Sensor using Density Functional Theory.

The influences of metal atoms on optimized geometry structures, relative energies, frontline molecular orbitals, and binding energies of metalloporphyrin-based fluorescent array sensor were systematically investigated by density functional theory (DFT) at B3LYP/LAN2DZ level. DFT calculated results reveal that the selected metal atoms in the center of the metalloporphyrin plane provide difference performances of metalloporphyrin-based fluorescent array sensor for the rapid determination of trimethylamine. The calculated binding energies have displayed in the following order at the most stable states: zinc porphyrin (ZnP) < copper porphyrin (CuP) < silver porphyrin (AgP) < iron porphyrin (FeP) < tin porphyrin (SnP) < cobalt porphyrin (CoP) < ruthenium porphyrin (RuP) < manganese porphyrin (MnP). Therefore, this theoretical study provides a design mechanism for how to choose a proper metal atom for low or high concentration trimethylamine. This research also suggests that theoretical results may be useful for the rapid detection of food containing trimethylamine.

Mechanisms and kinetic studies of OH-initiated atmospheric oxidation of methoxyphenols in the presence of O2 and NOx.

Methoxyphenols, as the main products and tracers of biomass burning, have been demonstrated to play an important role in the formation of secondary organic aerosols. However, their chemical transformation and migration in the atmosphere haven't been well characterized. In this study, detailed gas-phase reaction mechanisms and kinetics of three representative methoxyphenols (guaiacol, creosol and syringol) with OH radicals were investigated by using density functional theory (DFT). The initial reactions of methoxyphenols with OH radicals proceed via two different patterns, including OH-addition and H-atom abstraction. Subsequent reaction schemes of the active intermediates in the presence of O2/NOx are thoughtfully modeled. Catechol, methyl glyoxylate, malealdehyde and carbonyl or carboxyl compounds were confirmed as the dominant oxidation products for guaiacol. As a supplementary study, the formation pathways for the expected products nitroguaiacol and nitrocatechol were presented in high-NO2 conditions. Total and individual rate coefficients are calculated using the MESMER program at 294 K and 1 atm. The lifetimes of guaiacol, creosol and syringol were estimated to be 4.27, 3.56 and 2.98 hours, respectively, which are strongly competitive with the solar photolysis of methoxyphenols.

One-Step Hydrothermal Synthesis of SnO2@Carbon Composites with Super Lithium Ions Storage Performances.

Tin oxide (SnO2) based anode materials for lithium ion batteries (LIBs) have drawn much attention for their high theoretical capacity and energy density, but suffer from a large volume change and resulting a rapid capacity fading during charging/discharging cycles. To optimize the status, herein, SnO2/carbon composites are synthesized using SnCl4 · 5H2O and glucose with different mass ratio as raw materials via a simple one-step hydrothermal process, following calcination under Ar gas atmosphere. As comparison, pure SnO2 is synthesized as the same as SnO2/carbon composites without glucose and calcination in air. The electrochemical impedance spectroscopy (EIS) measurements were used to investigate the lithium ions storage behavior in pure SnO2 and the SnO2@carbon composites. The EIS results indicate that pure SnO2 has much larger electronic transfer resistance and smaller diffusion coefficient of Li+ resulting worst electrochemical performances, while carbon can substantially enhance the electronic conductivity of the composites and resulting better cycle stability and rate capability of the composite anodes. Moreover, the stability and capacity of the composites are different from each other due to diverse carbon content, surface area and particle size, in which, SnO2-24%C exhibits better lithium storage performances. The initial discharge/charge capacities are up to 1650 and 890 mAh g-1 at the current density of 0.2 A g-1, and the reversible capacity even still maintains at 800 mAh g-1 after 60 cycles. The super electrochemical performances are attributed to that the proper content of carbon clusters as a support can buffer volume expansion of SnO2 during cycling, enhance the electrode conductivity and accelerate the diffusion of Li+ ions in the composite. The results implying that the composite with proper carbon content has a wide application prospect for anode material of LIBs.