Study of 400 MHz microwave conduction loss effect for a hydrolysis reaction by thermostable ß-Glucosidase HT1.

Microwave irradiation at different frequencies gave molecular selective effects, namely higher frequency microwave effects for waters while lower frequency effects for ions. We already reported that 2.45 GHz and 5.80 GHz microwave irradiation gave different results for a hydrolysis reaction by thermostable ß-Glucosidase HT1. Here, we designed and made a reactor, employed 400 MHz microwave irradiation, and studied the effectiveness of 400 MHz microwave for HT1 reaction, then 400 MHz and 2.45 GHz had the ability to accelerate HT1 reaction. In consideration of the general mechanism of enzymatic glycoside hydrolysis, our results would be reasonable if ions are key reaction species because 400 MHz microwave activated ions selectively. In addition, the phenomenon that 400 MHz microwave would not affect water molecules by dielectric heating might contribute the enzyme stability. This report should support that microwave is not only a tool to heat reactions efficiently but also can bring unique effects for reactions.

Structural Transition with a Sharp Change in the Electrical Resistivity and Spin-Orbit Mott Insulating State in a Rhenium Oxide, Sr3Re2O9.

We report the successful synthesis, crystal structure, and electrical properties of Sr3Re2O9, which contains Re6+ with the 5d1 configuration. This compound is isostructural with Ba3Re2O9 and shows a first-order structural phase transition at ∼370 K. The low-temperature (LT) phase crystallizes in a hettotype structure of Ba3Re2O9, which is different from that of the LT phase of Sr3W2O9, suggesting that the electronic state of Re6+ plays an important role in determining the crystal structure of the LT phase. The structural transition is accompanied by a sharp change in the electrical resistivity. This is likely a metal-insulator transition, as suggested by the electronic band calculation and magnetic susceptibility. In the LT phase, the ReO6 octahedra are rotated in a pseudo-a0a0a+ manner in Glazer notation, which corresponds to C-type orbital ordering. Paramagnetic dipole moments were confirmed to exist in the LT phase by muon spin rotation and relaxation measurements. However, the dipole moments shrink greatly because of the strong spin-orbit coupling in the Re ions. Thus, the electronic state of the LT phase corresponds to a Mott insulating state with strong spin-orbit interactions at the Re sites.

Na-ion mobility in P2-type Na0.5MgxNi0.17-xMn0.83O2 (0 ≤ x ≤ 0.07) from electrochemical and muon spin relaxation studies.

Sodium transition metal oxides with a layered structure are one of the most widely studied cathode materials for Na+-ion batteries. Since the mobility of Na+ in such cathode materials is a key factor that governs the performance of material, electrochemical and muon spin rotation and relaxation techniques are here used to reveal the Na+-ion mobility in a P2-type Na0.5MgxNi0.17-xMn0.83O2 (x = 0, 0.02, 0.05 and 0.07) cathode material. Combining electrochemical techniques such as galvanostatic cycling, cyclic voltammetry, and the galvanostatic intermittent titration technique with µ+SR, we have successfully extracted both self-diffusion and chemical-diffusion under a potential gradient, which are essential to understand the electrode material from an atomic-scale viewpoint. The results indicate that a small amount of Mg substitution has strong effects on the cycling performance and the Na+ mobility. Amongst the tested cathode systems, it was found that the composition with a Mg content of x = 0.02 resulted in the best cycling stability and highest Na+ mobility based on electrochemical and µ+SR results. The current study clearly shows that for developing a new generation of sustainable energy-storage devices, it is crucial to study and understand both the structure as well as dynamics of ions in the material on an atomic level.

Nondestructive High-Sensitivity Detections of Metallic Lithium Deposited on a Battery Anode Using Muonic X-rays.

Metallic Li deposited on the anode is known to induce short circuiting and degradation of the charge capacity of Li-ion batteries. However, no reliable technique is currently available to observe such Li metal without removing the case of the battery. An elemental analysis using muonic X-rays is proposed here because of its unique properties of nondestructive measurement, high sensitivity to light elements, and depth resolution. We demonstrated that this technique can be applied to detection of Li deposited on the surface of an anode containing Li ions, using a fully charged anode with Li deposited due to overcharge in an Al-laminated plastic pouch. The basis for the detection method is the difference in the atomic Coulomb capture ratio of the negative muons between the Li metal and ions. We have found, as a result, that the intensity of the muonic X-rays from metallic Li was approximately 50 times higher than that from Li ions. Consequently, the Li metal on the anode was clearly distinguishable from the intercalated Li ions in the anode. Furthermore, measurements of two overcharged anodes with 1.3 and 2.7 mg of metallic Li deposition, respectively, indicated that this technique is suitable for quantitative analysis. Distribution analysis is also possible, as shown by a preliminary observation on an overcharged anode from the back side. Therefore, this technique offers a new approach to the analysis of Li deposited on the anode of a Li-ion pouch battery.

Electromagnetic Relationship between Microwaves and Flow Reactor Systems.

One of the important points in handling microwaves is that the order of magnitude is decimeter order. Laboratory equipment is not too big for wavelength, so intensity nonuniformity may occur. Another important point is that microwave propagation changes with material parameter changes. To heat material in the planned shape, the consideration with electromagnetism about the equipment and the system will be necessary. Herein, the phenomena which should be considered when a flow reactor is irradiated with a microwave is described.

Linear Trimer Formation with Antiferromagnetic Ordering in 1T-CrSe2 Originating from Peierls-like Instabilities and Interlayer Se-Se Interactions.

Anomalous successive structural transitions in layered 1T-CrSe2 with an unusual Cr4+ valency were investigated by synchrotron X-ray diffraction. 1T-CrSe2 exhibits dramatic structural changes in in-plane Cr-Cr and interlayer Se-Se distances, which originate from two interactions: (i) in-plane Cr-Cr interactions derived from Peierls-like trimerization instabilities on the orbitally assisted one-dimensional chains and (ii) interlayer Se-Se interactions through p-p hybridization. As a result, 1T-CrSe2 has the unexpected ground state of an antiferromagnetic metal with multiple Cr linear trimers with three-center-two-electron σ bonds. Interestingly, partial substitution of Se for S atoms in 1T-CrSe2 changes the ground state from an antiferromagnetic metal to an insulator without long-range magnetic ordering, which is due to the weakening of interlayer interactions between anions. The unique low-temperature structures and electronic states of this system are determined by the competition and cooperation of in-plane Cr-Cr and interlayer Se-Se interactions.

Nuclear Magnetic Field in Solids Detected with Negative-Muon Spin Rotation and Relaxation.

Using an intense negative muon (µ^{-}) source, we have studied the internal magnetic fields in a powder sample of magnesium hydride (MgH_{2}). By extracting the signal from the µ^{-} captured on Mg nuclei, we found that the negative muon spin rotation and relaxation (µ^{-}SR) spectra clearly showed a Kubo-Toyabe-type relaxation, which indicates a random magnetic field at the Mg site. The field distribution width obtained is very consistent with the predicted value at the Mg site estimated by dipole field calculations, supporting our claim to have observed the nuclear magnetic fields of hydrogens in MgH_{2}. As is the case with µ^{+}SR, µ^{-}SR promises to soon be an indispensable tool for materials analyses.

Selective, Scalable Synthesis of C60-Fullerene/Indene Monoadducts Using a Microwave Flow Applicator.

The synergy of continuous processing and microwave heating technologies has unlocked scalable (g/h), safe and efficient reaction conditions for synthesis of fullerene/indene-based organic photovoltaic acceptor materials in a nonchlorinated solvent with levels of productivity unparalleled by previous syntheses. The microwave flow reactor sustains high temperature while employing short residence times, reaction conditions which uniquely allow the selective synthesis of fullerene/indene monoadducts. Design of experiments analysis revealed residence time as the most crucial factor for conversion and selectivity control.

Li-ion diffusion in Li intercalated graphite C6Li and C12Li probed by µ+SR.

In order to study a diffusive behavior of Li+ in Li intercalated graphites, we have measured muon spin relaxation (µ+SR) spectra for C6Li and C12Li synthesized with an electrochemical reaction between Li and graphite in a Li-ion battery. For both compounds, it was found that Li+ ions start to diffuse above 230 K and the diffusive behavior obeys a thermal activation process. The activation energy (Ea) for C6Li is obtained as 270(5) meV, while Ea = 170(20) meV for C12Li. Assuming a jump diffusion of Li+ in the Li layer of C6Li and C12Li, a self-diffusion coefficient DLi at 310 K was estimated as 7.6(3) × 10-11 (cm2 s-1) in C6Li and 14.6(4) × 10-11 (cm2 s-1) in C12Li.

ß-NMR measurements of molecular-scale lithium-ion dynamics in poly(ethylene oxide)-lithium-salt thin films.

ß-detected NMR (ß-NMR) has been used to study the molecular-scale dynamics of lithium ions in thin films of poly(ethylene oxide) (PEO) containing either lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) or lithium trifluoroacetate (LiTFA) salts at monomer-to-salt ratios (EO/Li) of 8.3. The results are compared with previous ß-NMR measurements on pure PEO and PEO with lithium triflate (LiOTf) at the same loading [McKenzie et al., J. Am. Chem. Soc. 136, 7833 (2014)]. Activated hopping of 8Li+ was observed in all of the films above ∼250 K, with the hopping parameters strongly correlated with the ionicity of the lithium salt rather than the polymer glass transition temperature. The pre-exponential factor increases exponentially with ionicity, while the activation energy for hopping increases approximately linearly, going from 6.3±0.2 kJ mol-1 in PEO:LiTFA to 17.8±0.2 kJ mol-1 in PEO:LiTFSI. The more rapid increase in the pre-exponential factor outweighs the effect of the larger activation energy and results in 8Li+ hopping being fastest in PEO followed by PEO:LiTFSI, PEO:LiOTf, and PEO:LiTFA.

Magnetic anomalies and itinerant character of electrochemically Li-inserted Li[Li1/3Ti5/3]O4.

Spinel oxides of Li[LiyTi2-y]O4 with 0 ≤y≤ 1/3 exhibit two desirable features for solid state chemistry and condensed matter physics. One is a reversible lithium insertion/extraction reaction, in particular for Li[Li1/3Ti5/3]O4, and the other is a superconducting transition at Tc≃ 13 K for Li[Ti2]O4. To study the change in magnetic environments of the y = 1/3 compound with excess Li(x), we measured the magnetic susceptibility (χ) for the Li1+x[Li1/3Ti5/3]O4 samples with 0 ≤x≤ 0.95, which were prepared by an electrochemical Li insertion reaction into Li[Li1/3Ti5/3]O4. Even for the x = 0 sample, two magnetic anomalies were found at T (=63 K) and T (=21 K), despite the fact that all Ti ions should be in the 4+ state with S = 0. A comparative study of TiO2 and Li2TiO3 revealed that these magnetic anomalies are not impurity-induced effects but are caused by an intrinsic nature of Li[Li1/3Ti5/3]O4, probably due to either slight compositional deviation from stoichiometry or dislocations such as a Magnéli phase. For the x > 0 samples, the χ vs. temperature curve was found to consist of a temperature-independent Pauli-paramagnetic contribution and a Curie-Weiss contribution. Detailed analyses of χ clarified the systematic variations of the effective magnetic moment of Ti ions, effective mass of electrons in the conduction band, and density of states at the Fermi level with x, indicating that the Li(+) ions at the 16d site play a significant role in localizing d electrons of Ti(3+) ions.

ß-NMR measurements of lithium ion transport in thin films of pure and lithium-salt-doped poly(ethylene oxide).

ß-Detected nuclear spin relaxation of (8)Li(+) has been used to study the microscopic diffusion of lithium ions in thin films of poly(ethylene oxide) (PEO), where the implanted lithium ions are present in extremely low concentration, and PEO with 30 wt % LiCF3SO3 over a wide range of temperatures both above and below the glass transition temperature. Recent measurements by Do et al. [Phys. Rev. Lett. 2013, 111, 018301] found that the temperature dependence of the Li(+) conductivity was identical to that of the dielectric α relaxation and was well described by the Vogel-Fulcher-Tammann relation, implying the α relaxation dominates the Li(+) transport process. In contrast, we find the hopping of Li(+) in both samples in the high temperature viscoelastic phase follows an Arrhenius law and depends significantly on the salt content. We propose that the hopping of Li(+) between cages involves motion of the polymer but that it is only for long-range diffusion where the α relaxation plays an important role.

Understanding composition-property relationships in Ti-Cr-V-Mo alloys for optimisation of hydrogen storage in pressurised tanks.

The location of hydrogen within Ti-Cr-V-Mo alloys has been investigated during hydrogen absorption and desorption using in situ neutron powder diffraction and inelastic neutron scattering. Neutron powder diffraction identifies a low hydrogen equilibration pressure body-centred tetragonal phase that undergoes a martensitic phase transition to a face-centred cubic phase at high hydrogen equilibration pressures. The average location of the hydrogen in each phase has been identified from the neutron powder diffraction data although inelastic neutron scattering combined with density functional theory calculations show that the local structure is more complex than it appears from the average structure. Furthermore the origin of the change in dissociation pressure and hydrogen trapping on cycling in Ti-Cr-V-Mo alloys is discussed.

Efficiency of 2.45 and 5.80 GHz microwave irradiation for a hydrolysis reaction by thermostable ß-Glucosidase HT1.

Microwave irradiation at different frequencies gave unique results for the hydrolyses of glycosyl bonds by ß-Glucosidase HT1. With the observed relative complex permittivity data for the reaction buffer, 2.45 GHz microwave radiation affected both waters and ions, while 5.80 GHz only affected waters. We, here, propose that would be one of the unique "microwave nonthermal effects".

Sex Disparities in Applied Force on Maxillary Incisors Among Novices During Laryngoscopy Using a High-Fidelity Simulator: A Prospective Observational Study.

Endotracheal intubation (ETI) is a common and crucial intervention. Whether the performance of ETI differs according to the sex of the laryngoscopist remains unclear. The aim of this study was to assess sex disparities in markers of ETI performance among novices using a high-fidelity simulator. This prospective observational study was conducted from April 2017 to March 2019 in a public medical university. In total, 209 medical students (4th and 5th grade) without clinical ETI experience were recruited. Of the 209 students, 64 (30.6%) were female. The participants used either a Macintosh direct laryngoscope or C-MAC video laryngoscope in combination with a stylet or gum-elastic bougie to perform ETI on a high-fidelity simulator. The primary endpoint was the maximum force applied on the maxillary incisors during laryngoscopy. The secondary endpoint was the time to ETI. The implanted sensors in the simulator automatically quantified the force and time to ETI. The maximum force applied on the maxillary incisors was approximately 30% lower in the male than female group for all laryngoscopes and intubation aids examined (all P < 0.001). Similarly, the time to ETI was approximately 10% faster in the male than female group regardless of the types of laryngoscopes and intubation aids used (all P < 0.05). In this study, male sex was associated with a lower maximum force applied on the maxillary incisors during both direct and indirect laryngoscopy performed by novices. A clinical study focusing on sex differences in ETI performance is needed to validate our findings.

Reactive surface area of the Li(x)(Co(1/3)Ni(1/3)Mn(1/3))O2 electrode determined by µ(+)SR and electrochemical measurements.

The self-diffusion coefficient of Li(+) ions (D(Li)) in the positive electrode material Li(x)(Co(1/3)Ni(1/3)Mn(1/3))O2 has been estimated by muon-spin relaxation (µ(+)SR) using powder samples with x = 1-0.49, which were prepared by an electrochemical reaction in a Li-ion battery. Here, since the implanted muons sense a slight change in the internal magnetic field due to Li-diffusion, µ(+)SR provides an intrinsic D(Li) through the temperature dependence of the nuclear field fluctuation rate (ν) [Sugiyama et al., Phys. Rev. Lett., 2009, 103, 147601]. Both D(Li) at 300 K and activation energy (E(a)) were estimated to be ∼2.9 × 10(-12) cm(2) s(-1) and 0.074 eV for the x = 1 sample, ∼11.0 × 10(-12) cm(2) s(-1) and 0.097 eV for x = 0.70, and ∼8.9 × 10(-12) cm(2) s(-1) and 0.062 eV for x = 0.49, assuming that the diffusing Li(+) ions mainly jump from a regular occupied site to a regular vacant site. The estimated D(Li) was smaller by roughly one order of magnitude than those for Li(x)CoO2 in the whole x range measured. Furthermore, by making comparison with D(Li) obtained by electrochemical measurements, the reactive surface area of the Li(x)(Co(1/3)Ni(1/3)Mn(1/3))O2 electrode in a liquid electrolyte was found to strongly depend on x particularly at x > 0.8.

Nonthermal acceleration of protein hydration by sub-terahertz irradiation.

The collective intermolecular dynamics of protein and water molecules, which overlap in the sub-terahertz (THz) frequency region, are relevant for expressing protein functions but remain largely unknown. This study used dielectric relaxation (DR) measurements to investigate how externally applied sub-THz electromagnetic fields perturb the rapid collective dynamics and influence the considerably slower chemical processes in protein-water systems. We analyzed an aqueous lysozyme solution, whose hydration is not thermally equilibrated. By detecting time-lapse differences in microwave DR, we demonstrated that sub-THz irradiation gradually decreases the dielectric permittivity of the lysozyme solution by reducing the orientational polarization of water molecules. Comprehensive analysis combining THz and nuclear magnetic resonance spectroscopies suggested that the gradual decrease in the dielectric permittivity is not induced by heating but is due to a slow shift toward the hydrophobic hydration structure in lysozyme. Our findings can be used to investigate hydration-mediated protein functions based on sub-THz irradiation.

Ultrasound-based upper limb muscle thickness is useful for screening low muscularity during intensive care unit admission: A retrospective study.

BACKGROUND & AIMS: Malnutrition is associated with poor outcomes. Muscle mass is an important malnutrition indicator included in Global Leadership Initiative on Malnutrition (GLIM) criteria. Although bioelectrical impedance analysis and dual-energy X-ray absorptiometry are common muscle mass assessment methods, they are unreliable during intensive care unit (ICU) admission due to the influence of dynamic fluid changes. We hypothesized that ultrasound-based upper limb muscle assessment would be useful for assessing muscularity at ICU admission. METHODS: We retrospectively analyzed prospectively obtained ultrasound data from patients admitted to an ICU. We excluded patients without computed tomography (CT) imaging of the third lumbar vertebra within 2 days of ICU admission. Primary outcomes were the diagnostic utility of ultrasound-based upper limb muscle thickness for assessing low muscularity by CT. Low muscularity was defined as a skeletal muscle index of 36.0 cm2/m2 for males and 29.0 cm2/m2 for females at the cross-sectional area of the third lumbar vertebrae. Secondary outcomes of this study included the relationships between upper limb muscle thickness and biceps brachii muscle cross-sectional area, quadriceps femoris thickness, rectus femoris cross-sectional area. RESULTS: Among 64 patients assessed by ultrasound, 52 had CT examination records and were included in the analysis. The mean age was 70 ± 13 years, and the mean body mass index was 23.3 ± 4.2 kg/m2. Upper limb muscle thickness had the discriminative power to assess low muscularity at an area under the curve of 0.77 (95% CI [confidence interval], 0.63-0.91); the cutoff value (26.8 cm) had 84.6% sensitivity and 66.7% specificity. The upper limb muscle index had the discriminative power to assess low muscularity at an area under the curve of 0.80 (95% CI, 0.68-0.93); the cutoff value (9.9 mm/m2) had 76.9% sensitivity and 71.8% specificity. Upper limb muscle thickness was correlated with upper limb muscle cross-sectional area, quadriceps femoris muscle thickness, rectus femoris muscle cross-sectional area (r = 0.39-0.76, p < 0.01, n = 52). CONCLUSIONS: Ultrasound-based upper limb muscle thickness assessments can screen for low muscularity upon ICU admission.

Impact of the coronavirus disease 2019 (COVID-19) pandemic on the operational efficiency of emergency medical services and its association with out-of-hospital cardiac arrest survival rates: A population-based cohort study in Kobe, Japan.

Aim: To identify whether the coronavirus disease 2019 (COVID-19) pandemic affects the operational efficiency of emergency medical services (EMS) and the survival rate of out-of-hospital cardiac arrest (OHCA) in prehospital settings. Methods: We conducted a population-based cohort study in Kobe, Japan, between March 1, 2020, and September 31, 2022. In study 1, the operational efficiency of EMS, such as the total out-of-service time for ambulances, the daily occupancy rate of EMS, and response time, was compared between the pandemic and nonpandemic periods. In study 2, the impacts of the changes in EMS operational efficiency were investigated among patients with OHCA, with 1-month survival as the primary outcome and return of spontaneous circulation, 24-h survival, 1-week survival, and favorable neurological outcomes as the secondary outcomes. Logistic regression analysis was conducted to identify the factors associated with survival among patients with OHCA. Results: The total out-of-service time, occupancy rate, and response time significantly increased during the pandemic period (p < 0.001). The response time during the pandemic period increased significantly per pandemic wave. Regarding OHCA outcomes, 1-month survival rates during the pandemic period significantly decreased compared with those during the nonpandemic period (pandemic 3.7% vs. nonpandemic 5.7%; p < 0.01). Similarly, 24-h survival (9.9% vs. 12.8%), and favorable neurological outcomes significantly decreased during the pandemic period. In the logistic regression analysis, response time was associated with lower OHCA survival in all outcomes (p < 0.05). Conclusion: The COVID-19 pandemic has been associated with reduced operational efficiency of EMS and decreased OHCA survival rates. Further research is required to improve the efficiency of EMS and OHCA survival rates.

Na Diffusion in Hard Carbon Studied with Positive Muon Spin Rotation and Relaxation.

The diffusive nature of Na+ in Na-inserted hard carbon (C x Na), which is the most common anode material for a Na-ion battery, was studied with a positive muon spin rotation and relaxation (µ+SR) technique in transverse, zero, and longitudinal magnetic fields (TF, ZF, and LF) at temperatures between 50 and 375 K, where TF (LF) denotes the applied magnetic field perpendicular (parallel) to the initial muon spin polarization. At temperatures above 150 K, TF-µ+SR measurements showed a distinct motional narrowing behavior, implying that Na+ begins to diffuse above 150 K. The presence of two different muon sites in C x Na was confirmed with ZF- and LF-µ+SR measurements; one is in the Na-inserted graphene layer, and the other is in the Na-vacant graphene layer adjacent to the Na-inserted graphene layer. A systematic increase in the field fluctuation rate (ν) with increasing temperature also evidenced a thermally activated Na diffusion, particularly above 150 K. Assuming the two-dimensional diffusion of Na+ in the graphene layers, the self-diffusion coefficient of Na+ (D Na J) at 300 K was estimated to be 2.5 × 10-11 cm2/s with a thermal activation energy of 39(7) meV.