Polysiloxane-based Electrolytes: Influence of Salt Type and Polymer Chain Length on the Physical and Electrochemical Properties.

An oligo/poly(methyl(2-(tris(2-H methoxyethoxy)silyl)ethyl)siloxane)), 390EO, and 2550EO, were synthesized. Dilute electrolyte solutions of 390EO and 2550EO were prepared using LiTFSI, LiFSI, and LiPF6 . The influence of the length of the siloxane polymer chain, salt type, and Si-tripodand centers at the side chain on ionic conductivity, tLi + , and physical properties were examined. Both electrolyte systems showed high values of tLi + (0.35 for 2550EO/LiTFSI and 0.64 for 390EO/LiTFSI). Alternatively 390EO/LiPF6 and 2550EO/LiPF6 displayed high tLi + values of 0.61 and 0.44, respectively, while 390EO/LiFSI displayed the smallest tLi+ (0.25). To clarify the role played by the Li+ environment in Li+ transport, the solvation states of electrolytes were examined. It was observed that anion solvation can be achieved using siloxane-based solvent in all systems. Walden plot analysis demonstrates that ionic diffusion was not controlled by either macroviscosity/microviscosity in the siloxane-based polymer electrolytes. Ions instead move along a relatively smooth ion-pathway without complete full segmental reorientation in 2550EO as a result of decoupling and high ion solvation behavior. Conversely, in 390EO, ions might move to available sites by a jumping after decoupling with low ion solvation behavior. Consequently, a high t Li + was achieved, and the oxidative stability of the salt was ensured.

Evolutionary Algorithm Directed Synthesis of Mixed Anion Compounds LaF2 X (X=Br, I) and LaFI2.

Mixed-anion compounds have attracted growing attentions, but their synthesis is challenging, making a rational search desirable. Here, we explored LaF3 -LaX3 (X=Cl, Br, I) system using ab initio structure searches based on evolutionary algorithms, and predicted LaF2 X and LaFX2 (X=Br, I), which are respectively isostructural with LaHBr2 and YH2 I, consisting of layered La-F blocks with single and double ordered honeycomb lattices, separated by van der Waals gaps. We successfully synthesized these compounds: LaF2 Br and LaFI2 crystallize in the predicted structure, while LaF2 I is similar to the predicted one but with different layer stacking. LaF2 I exhibits fluoride ion conductivity comparable to that of non-doped LaF3 , and has the potential to show better ionic conductivity upon appropriate doping, given the theoretically lower diffusion energy barrier and the presence of soft iodine anions. This study shows the structure prediction using evolutionary algorithms will accelerate the discovery of mixed-anion compounds in future, in particular those with an ordered anion arrangement.

Fluoride Ion-Selective Electrode for Organic Solutions.

Fluoride ions are used in battery electrolytes in fluoride shuttle batteries. Since organic solvents are used in battery electrolytes, there is a growing demand to develop appropriate methods for quantifying fluoride ion concentration in organic solvents. In this study, a fluoride ion-selective electrode (ISE) for organic solutions is proposed as an electrode of the second kind. A Ag|AgF electrode was made via the anodization of a silver wire in propylene carbonate (PC) containing dissolved fluoride ions. The resultant electrode exhibits a stable linear response of the open circuit potential to the logarithm of the fluoride ion concentration in PC solutions over a range of 10-4-10-2 mol dm-3. The lower and upper limits of the linear response were interpreted in terms of the solubility and the formation of a silver fluoride complex. The use of this electrode of the second kind is suitable for the analysis of fluoride ions in organic solutions and is a promising concept for the development of ISEs for the detection of ions in organic solutions under highly restrictive conditions.

Dynamic manipulation of the local pH within a nanopore triggered by surface-induced phase transition.

Manipulating the local pH within nanoconfinement is essential in nanofluidics technology and its applications. Since the conventional strategy utilizes the overlapping of an electric double layer formed for charge compensation by protons near a negatively charged pore-wall surface, pH variation within a pore is limited to the acidic side. To achieve the variation at the alkaline side, we developed a system comprising a hydrophobic pore-wall surface and aqueous solution containing hydrophobic cations. Beyond a threshold cation concentration, a nanopore is filled with the second phase where the cations are remarkably enriched due to surface-induced phase transition (SIFT) originating from the hydrophobic effect. It is accompanied by the enrichment of coexisting anions. We experimentally show that pH in the second phase is much higher than in the bulk solution. Electrochemical measurements strongly suggest that the pH value can be increased from 4.8 to 10.7 within a 10 nm nanopore in the most significant case. This is ascribed to the enrichment of hydroxide anions. We argue that the extent and rate of pH variation are controlled as desired.

Interface structure between tetraglyme and graphite.

Clarification of the details of the interface structure between liquids and solids is crucial for understanding the fundamental processes of physical functions. Herein, we investigate the structure of the interface between tetraglyme and graphite and propose a model for the interface structure based on the observation of frequency-modulation atomic force microscopy in liquids. The ordering and distorted adsorption of tetraglyme on graphite were observed. It is found that tetraglyme stably adsorbs on graphite. Density functional theory calculations supported the adsorption structure. In the liquid phase, there is a layered structure of the molecular distribution with an average distance of 0.60 nm between layers.

Development of a method for estimating oesophageal temperature by multi-locational temperature measurement inside the external auditory canal.

We aimed to develop a practical method to estimate oesophageal temperature by measuring multi-locational auditory canal temperatures. This method can be applied to prevent heatstroke by simultaneously and continuously monitoring the core temperatures of people working under hot environments. We asked 11 healthy male volunteers to exercise, generating 80 W for 45 min in a climatic chamber set at 24, 32 and 40 °C, at 50% relative humidity. We also exposed the participants to radiation at 32 °C. We continuously measured temperatures at the oesophagus, rectum and three different locations along the external auditory canal. We developed equations for estimating oesophageal temperatures from auditory canal temperatures and compared their fitness and errors. The rectal temperature increased or decreased faster than oesophageal temperature at the start or end of exercise in all conditions. Estimated temperature showed good similarity with oesophageal temperature, and the square of the correlation coefficient of the best fitting model reached 0.904. We observed intermediate values between rectal and oesophageal temperatures during the rest phase. Even under the condition with radiation, estimated oesophageal temperature demonstrated concordant movement with oesophageal temperature at around 0.1 °C overestimation. Our method measured temperatures at three different locations along the external auditory canal. We confirmed that the approach can credibly estimate the oesophageal temperature from 24 to 40 °C for people performing exercise in the same place in a windless environment.

In situ Raman investigation of electrolyte solutions in the vicinity of graphite negative electrodes.

The structure of electrolyte solutions plays an important role in the lithium-ion intercalation reaction at graphite negative electrodes. The solvation structure of an electrolyte solution in bulk has been investigated previously. However, the structure of an electrolyte solution at the graphite negative electrode/electrolyte solution interface, where the lithium-ion intercalation reaction occurs is more important. In this study, the structure of electrolyte solutions in the vicinity of a graphite negative electrode was investigated using in situ Raman spectroscopy during the 1st reduction process in 1 mol dm-3 LiClO4/ethylene carbonate (EC) + diethyl carbonate (DEC) (1 : 1 volume ratio), 1 mol dm-3 LiCF3SO3/propylene carbonate (PC), and 1 mol dm-3 LiCF3SO3/PC + tetraethylene glycol dimethyl ether (tetraglyme) (20 : 1 volume ratio). As a result, in the electrolyte solutions in which the lithium-ion intercalation reaction can occur (LiClO4/EC + DEC and LiCF3SO3/PC + tetraglyme), the Raman spectra of free solvent molecules (EC or PC) and anions showed a positive vibrational frequency shift during the co-intercalation reaction, and these shifts returned to their original positions during the lithium-ion intercalation reaction. On the other hand, there is no vibrational frequency shift in LiCF3SO3/PC, an electrolyte in which the lithium-ion intercalation reaction cannot occur. Based on our results, the relationship between the Raman shift and the solid electrolyte interphase (SEI) formation process was discussed.

A comparative study on the impact of different glymes and their derivatives as electrolyte solvents for graphite co-intercalation electrodes in lithium-ion and sodium-ion batteries.

The abundance of sodium has recently sparked considerable interest in sodium-ion batteries (NIBs). Their similarity to conventional lithium-ion technology is obvious; however, the cell chemistry often significantly deviates. Graphite, although being the standard negative electrode in Li-ion batteries, is largely inactive for Na-ion storage in conventional non-aqueous carbonate-based electrolytes, for example. Very recently, it has been demonstrated that graphite can be activated for Na-ion storage in cells with ether-based electrolytes. The storage mechanism is based on co-intercalation of solvent molecules along with the Na-ions, forming ternary graphite intercalation compounds (t-GICs). This process is highly reversible but yet poorly understood. Here, we provide a comprehensive study on the formation and the stability of t-GICs. A series of ether solvents are being discussed: linear glymes with different chain lengths (mono-, di-, tri-, and tetraglyme), several derivatives with side groups as well as tetrahydrofuran (THF) as a cyclic ether and one crown ether. We show that the redox potentials shift depending on the ether chain length and mixing of ethers might enable tailoring of the redox behaviour. The inferior behaviour of triglyme is likely due to the less ideal ion coordination. Complementary experiments with lithium are made and demonstrate the superior behaviour of sodium. We find that the increase in graphene layer spacing during intercalation only slightly depends on the chain length and is in the range of 250%, and still mechanical stability is preserved. We further show the t-GICs possess chemical stability and demonstrate that the kinetically favoured charge transfer is probably due to the absence of a solid electrolyte interphase.

Irreversible morphological changes of a graphite negative-electrode at high potentials in LiPF6-based electrolyte solution.

The degradation mechanism of a graphite negative-electrode in LiPF6-based electrolyte solution was investigated using the basal plane of highly oriented pyrolytic graphite (HOPG) as a model electrode. Changes in the surface morphology were observed by in situ atomic force microscopy. In the initial cathodic scan, a number of pits appeared at around 1.75 V vs. Li(+)/Li, and fine particles formed on the terrace of the HOPG basal plane at about 1.5 V vs. Li(+)/Li. The fine particles were characterized by spectroscopic analysis, such as X-ray photoelectron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy. We added one of the components to LiClO4-based electrolyte solution, and successfully reproduced the formation of pits and fine particles on the basal plane of HOPG. Based on these results, the formation mechanisms of pits and fine particle layers were proposed.

Effect of calcination conditions on porous reduced titanium oxides and oxynitrides via a preceramic polymer route.

A preceramic polymer route from Ti-based inorganic-organic hybrid networks provides electroconductive N-doped reduced titanium oxides (TinO2n-1) and titanium oxynitrides (TiOxNy) with a monolithic shape as well as well-defined porous structures. This methodology demonstrates an advantageously lower temperature of the crystal phase transition compared to the reduction of TiO2 by carbon or hydrogen. In this study, the effect of calcination conditions on various features of the products has been explored by adopting three different atmospheric conditions and varying the calcination temperature. The detailed crystallographic and elemental analyses disclose the distinguished difference in the phase transition behavior with respect to the calcination atmosphere. The correlation between the crystallization and nitridation behaviors, porous properties, and electric conductivities in the final products is discussed.

Effect of cation species on surface-induced phase transition observed for platinum complex anions in platinum electrodeposition using nanoporous silicon.

In an earlier work [K. Fukami et al., J. Chem. Phys. 138, 094702 (2013)], we reported a transition phenomenon observed for platinum complex anions in our platinum electrodeposition experiment using nanoporous silicon. The pore wall surface of the silicon electrode was made hydrophobic by covering it with organic molecules. The anions are only weakly hydrated due to their large size and excluded from the bulk aqueous solution to the hydrophobic surface. When the anion concentration in the bulk was gradually increased, at a threshold the deposition behavior exhibited a sudden change, leading to drastic acceleration of the electrochemical deposition. It was shown that this change originates from a surface-induced phase transition: The space within a nanopore is abruptly filled with the second phase in which the anion concentration is orders of magnitude higher than that in the bulk. Here we examine how the platinum electrodeposition behavior is affected by the cation species coexisting with the anions. We compare the experimental results obtained using three different cation species: K(+), (CH3)4N(+), and (C2H5)4N(+). One of the cation species coexists with platinum complex anions [PtCl4](2-). It is shown that the threshold concentration, beyond which the electrochemical deposition within nanopores is drastically accelerated, is considerably dependent on the cation species. The threshold concentration becomes lower as the cation size increases. Our theoretical analysis suggests that not only the anions but also the cations are remarkably enriched in the second phase. The remarkable enrichment of the anions alone would give rise to the energetic instability due to electrostatic repulsive interactions among the anions. We argue that the result obtained cannot be elucidated by the prevailing view based on classical electrochemistry. It is necessitated to consult a statistical-mechanical theory of confined aqueous solutions using a molecular model for water.

Detection of quadratic phase coupling by cross-bicoherence and spectral Granger causality in bifrequencies interactions.

Quadratic Phase Coupling (QPC) serves as an essential statistical instrument for evaluating nonlinear synchronization within multivariate time series data, especially in signal processing and neuroscience fields. This study explores the precision of QPC detection using numerical estimates derived from cross-bicoherence and bivariate Granger causality within a straightforward, yet noisy, instantaneous multiplier model. It further assesses the impact of accidental statistically significant bifrequency interactions, introducing new metrics such as the ratio of bispectral quadratic phase coupling and the ratio of bivariate Granger causality quadratic phase coupling. Ratios nearing 1 signify a high degree of accuracy in detecting QPC. The coupling strength between interacting channels is identified as a key element that introduces nonlinearities, influencing the signal-to-noise ratio in the output channel. The model is tested across 59 experimental conditions of simulated recordings, with each condition evaluated against six coupling strength values, covering a wide range of carrier frequencies to examine a broad spectrum of scenarios. The findings demonstrate that the bispectral method outperforms bivariate Granger causality, particularly in identifying specific QPC under conditions of very weak couplings and in the presence of noise. The detection of specific QPC is crucial for neuroscience applications aimed at better understanding the temporal and spatial coordination between different brain regions.

Analysis of Malnutrition among Children under Five Years across Contrasting Agroecosystems of Northwest Ethiopia: Application of Structural Equation Modeling.

Child malnutrition remains a public health challenge in developing countries, but a comprehensive understanding of its burden and its determinants in specific local contexts is generally lacking. This study examined the prevalence of malnutrition and its determinants among children aged <5 years across contrasting agroecosystems in northwest Ethiopia. A community-based cross-sectional study involving 400 respondents was employed. Data were collected through semi-structured questionnaires and anthropometric measurements, complemented with focus group discussions and key informant interviews. The direct and indirect effects of the determinants of malnutrition were examined using structural equation modeling (SEM). The overall prevalence of child malnutrition, measured using the Composite Index of Anthropometric Failure, was 49%, with notable variation across agroecosystems (from 36.1% [midland with red soil] to 59% [lowland and valley fragmented]). Disease experience had significant positive direct effects on malnutrition. Dietary intake had negative and significant total (direct and indirect) effects on malnutrition, partially mediated through disease experience. Serial mediation in SEM analysis revealed significant indirect relationships between malnutrition and food security, feeding and care practices, household environment, health services, maternal diet, maternal empowerment, household wealth, and nutrition-sensitive agricultural practices. In conclusion, child malnutrition was highly prevalent and higher among children in the lowland and valley fragmented agroecosystem, characterized by unfavorable agro-climatic conditions, lower wealth status, poor health services access, and higher disease (particularly malaria) exposure. This study demonstrates the dynamics and multifaceted nature of malnutrition, highlighting the importance of considering geographical differences when planning interventions for childhood malnutrition and its determinants.

Elevations of neutrophil-to-lymphocyte ratio and C-reactive protein over time as a precursor to anaplastic transformation of papillary thyroid carcinoma: a case report.

BACKGROUND: Papillary thyroid carcinoma rarely undergoes anaplastic transformation. Some risk factors for anaplastic transformation of thyroid cancer are known, but such transformation is difficult to predict in practice. We report a case demonstrating elevations of neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein (CRP) over time as a precursor to anaplastic transformation of thyroid carcinoma. CASE PRESENTATION: The patient was an 89 year-old woman with a history of chronic aortic dissection. She was referred to our department after her local doctor detected thyroid nodules. She had previously been found to have multinodular goiter and enlarged left cervical lymph nodes on computed tomography. Her chief complaint was cervical discomfort and hoarseness. Blood tests revealed: white blood cells (WBCs), 4900 /µL; CRP, 0.29 mg/dL; neutrophils, 64.4%; and lymphocytes, 25.4%. A 21 mm mass was identified in the upper left lobe. Left III (16 mm) and left VI (16 mm) lymph node were enlarged on ultrasonography. Fine-needle aspiration cytology diagnosed malignant papillary carcinoma. However, due to the advanced age and medical history of the patient, a non-surgical policy was implemented. The primary tumor grew to 4 cm in diameter by 9 months after diagnosis, and blood tests showed: WBC, 7700 /µL; CRP, 0.18 mg/dL; neutrophils, 65.3%; and lymphocytes, 22.3%. By 10 months after diagnosis, the tumor had increased rapidly in diameter to 8 cm, with blood tests showing: WBC, 6500 /µL; CRP, 1.01 mg/dL; neutrophils, 68.2%; and lymphocytes, 19.3%. Anaplastic transformation of papillary thyroid carcinoma was diagnosed, and the patient was placed on treatment under a policy of best supportive care. Multiple lung metastases appeared 11 months after diagnosis, and blood test results showed: WBC, 13,300 /µL; CRP, 11.28 mg/dL; neutrophils, 93.6%; and lymphocytes, 2.3%. Unfortunately, the patient died of disease progression 63 days after identification of undifferentiated metastasis. CONCLUSIONS: Chances to see the natural history of anaplastic transformation of thyroid cancer are rare. Elevations in NLR and CRP over time may be precursors to anaplastic transformation.

New Li2FeSiO4-carbon monoliths with controlled macropores: effects of pore properties on electrode performance.

Monolithic Li2FeSiO4-carbon composites with well-defined macropores have been prepared from the silica-based gels containing Li, Fe, and carbon sources. The macroporous precursor gels can be fabricated by the sol-gel method accompanied by phase separation. A fine control of the macropore size in the resultant composites has been achieved by controlling the macropore size of the precursor gels simply by adjusting the starting compositions. The effects of pore properties on Li insertion-extraction capabilities have been investigated by utilizing the resultant Li2FeSiO4-carbon composites as the cathode of lithium ion batteries. The electrodes prepared from the Li2FeSiO4-carbon composites with different macropore sizes exhibit significant differences in the charge-discharge properties. The results strongly suggest that the smaller macropore size (equal to the thinner macropore skeletons) and the presence of micro- and mesopores in the macropore skeletons (hierarchically porous structure) are desirable for a better electrode in the case of Li2FeSiO4, which has extremely low ionic and electrical conductivities.

Influence of Strong Ionic Interaction on the Kinetics of Graphite Intercalation Compound Formation.

Graphite intercalation compounds (GICs) of anions have attracted much attention as a positive electrode for use in dual-ion batteries. In this study, GICs of bis(trifluoromethanesulfonyl)amide (TFSA) anions were electrochemically synthesized in ionic liquids with lithium or magnesium salts to investigate the kinetics of GICs formation. By varying the concentrations of LiTFSA or Mg(TFSA)2 , the activation energy of interfacial anion transfer resistance was discovered to be correlated with the viscosity of the ionic liquid electrolytes. Such a change in activation energy is unique to ionic liquids and not seen in common molecular solvent electrolytes. In addition, ionic liquids with nearly identical viscosities exhibited similar resistances and activation energies. The relationship between the viscosity of ionic liquids and the kinetic parameters of interfacial anion transfer found in this study provides important insights for the construction of dual-ion batteries that aim for both high capacity and high rate capability.

Estimating Culprit Drugs for Adverse Drug Reactions Based on Bayesian Inference.

The utility of big data in spontaneous adverse drug reactions (ADRs) reporting systems has improved the pharmacovigilance process. However, identifying culprit drugs in ADRs remains challenging, although it is one of the foremost steps to managing ADRs. Aiming to estimate the likelihood of prescribed drugs being culprit drugs for given ADRs, we devised a Bayesian estimation model based on the Japanese Adverse Drug Events Reports database. After developing the model, a validation study was conducted with 67 ADR reports with a gross of 1,387 drugs (67 culprit drugs and 1,320 concomitant drugs) prescribed and recorded at Yamaguchi University Hospital. As a result, the model estimated a culprit drug of ADRs with acceptable accuracy (area under the receiver operating characteristic curve 0.93 (95% confidence interval 0.88-0.97)). The estimation results provided by the model to healthcare practitioners can be used as one clue to determine the culprit drugs for various ADRs, which will improve the management of ADRs by shortening the treatment turnaround time and increasing the precision of diagnosis, leading to minimizing the adverse effects on patients.

Characteristics of the patients consulted with emergency medicine physicians at a large-scale COVID-19 vaccination center: Prospective observational study.

OBJECTIVE: We aimed to clarify the characteristics of patients consulted by the medical staff with emergency medicine (EM) physicians after vaccination and EM physicians transferred to an outside hospital. DESIGN: The Japanese Self-Defense Force established a large-scale coronavirus disease 2019 (COVID-19) vaccination center. Overall, 1,306,928 citizens received the Moderna vaccine, which targeted the first and second vaccinations between May 24, 2021 and November 30, 2021. EM physicians were always available in the emergency room (ER). The medical staff could consult the patients with EM physicians; however, the criteria were ambiguous. We conducted signal detection analysis on the patients who experienced adverse events to detect characteristics. RESULTS: Of the 3,312 patients experienced adverse events after vaccination, the medical staff consulted 344 with EM physicians. The patients whose respiratory rate and systolic blood pressure (BP) were more than 18 per minute and 162 mmHg, respectively, were considerably consulted. In addition, the patients whose systolic BP was more than 186.5 mmHg were transferred to an outside hospital. No patients were seriously ill or died after being transferred to an outside hospital. CONCLUSIONS: The medical staff consulted the patients with a high respiratory rate or BP with EM physicians. In addition to BP, the respiratory rate would also be necessary as a finding that suggests a patient's severity after vaccination. Therefore, it appears safer that EM physicians are always available to ensure the recipients' safety when running a new large-scale vaccination center against unknown diseases, such as COVID-19.