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Li-ion insertion into cerium dioxide (CeO2) and its subsequent conversion reaction were studied using a CeO2/copper composite electrode in a superconcentrated electrolyte of lithium bis(fluorosulfonyl)amide (LiFSA) and methylphenylamino-di(trifluoroethyl) phosphate (PNMePh) under conditions promoting Li plating/stripping. Since the conversion reaction potential with CeO2generally lies above the Li plating/stripping level, the conversion ideally occurs first in the cathodic scan. However, the conversion reaction was delayed until after the Li plating in the superconcentrated electrolyte contrary to expectations, whereas this phenomenon was unobserved in a dilute LiFSA/PNMePh electrolyte. Energy-dispersive X-ray spectroscopy and electrochemical impedance analysis indicated that the reversed order of the electrochemical behaviors was caused by the solid electrolyte interphase (SEI) on the CeO2, which had a different material composition and a higher interfacial resistance than the SEI on electrodeposited metallic lithium.

Lithium carbonate (Li2CO3) is observed in conventional lithium-ion batteries in which cell performance has been reduced. In this paper, a catalyst to electrochemically decompose Li2CO3was investigated to develop a Li reproduction technology. It has been accepted that iodine with a redox potential below 3.5 V vs Li+/Li cannot decompose Li2CO3, because the decomposition potential of Li2CO3is 3.82 V vs Li+/Li. Here, we observed that the redox potential of iodine in trimethyl phosphate (TMP) and dimethyl sulfoxide (DMSO) solutions increased up to 4.0 V, and thus Li2CO3could be chemically decomposed by iodine in these solvents. This unexpectedly high redox potential may be caused by deviation of the electric charges on two iodine atoms due to a 1:1 complex formation of iodine with the solvent. Reaction pathways are discussed with respect to the chemical decomposition of Li2CO3by iodine. We combined the chemical decomposition behavior with the redox couple of iodine species. A double-chamber type cell with carbon paper as cathode in catholyte that dissolved iodine and suspended Li2CO3powders was constructed to substantiate a catalytic cycle for Li2CO3decomposition. The cell was demonstrated to be rechargeable due to the decomposition of Li2CO3.

Asymptomatic patients who underwent PET/CT 1–180 days after their second SARS-CoV-2 vaccination showed increased myocardial fluorine 18 fluorodeoxyglucose uptake on images compared with nonvaccinated patients, but patients imaged more than 180 days after vaccination did not.

FDG-PET has been shown useful in the staging of malignant lymphoma (ML) and in evaluating treatment outcomes. Serum concentration of soluble interleukin-2 receptor (sIL-2R) has also been shown prognostic in patients with MLs. This study analyzed the clinical possibility of baseline FDG-PET parameters, such as maximum standardized uptake values (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and serum sIL-2R and lactate dehydrogenase (LDH) concentrations, as prognostic variables in patients with oral and neck non-Hodgkin’s lymphoma (NHL).

Phosphoric acid ester amides were examined as a new self-extinguishing solvent for Li-ion batteries. The phosphoric acid ester amides used in this study contained two fluorinated alkyl groups and one amino group, (CF3CH2O)2(NR1R2)P═O (PNR1R2). The thermal stability of the highly concentrated electrolyte of lithium bis(fluorosulfonyl) amide (LiFSA) and PNR1R2with a molar ratio of [LiFSA]/[PNR1R2] = 0.5 under overcharge depended on the modification of the amino substituent. Introduction of a phenyl group (R1= CH3, R2= C6H5) was effective for improving thermal stability. The release of gases and heat that typically accompanied reaction of the solvent with the charged graphite anode was greatly suppressed. Density functional theory calculations indicated that PNR1R2decomposed reductively near 0.5 V vs Li+/Li, suggesting poor Li ion insertion into the graphite. However, the highly concentrated electrolyte using LiFSA and PNR1R2reduced the reductive potential of PNR1R2and enabled not only the insertion of Li ions into the graphite but also reversible Li plating/stripping.

Our previous study demonstrated that a cadmium telluride (CdTe)-based single-photon emission computed tomography (SPECT) system with good energy resolution could provide dual-radioisotope SPECT images of a patient who had been administered with two kinds of radioisotope simultaneously. To obtain two quantitative physiological parametric images from these radioisotope images by using compartment model analysis, the concentrations of the dual-radioisotope in the blood sample need to be measured. In this paper, a CdTe-based well counter was developed to measure the concentrations of a dual-radioisotope of 99mTc and 123I, and its performance was evaluated. The counter consists of four detector panels. Each detector panel consists of two detector modules, and each module has $16\,\, {\times } \,\, 16$ CdTe detector pixels with a pitch of 2.5 mm; the eight detector modules give our system a field of view ( $ {x} {\times } \,\, {y} {\times } {z}$ ) of $4\,\, {\times } \,\, 4\,\, {\times } \,\, 8$ cm3. The crosstalk correction coefficient $ {{{\alpha }}}$ , which is the ratio of the count rate in the 99mTc-energy window to that in the 123I-energy window, was obtained by measuring the single-radioisotope solution of 123I. When the dual-radioisotope of 99mTc and 123I was measured, the true count rate of 99mTc was obtained by subtracting the crosstalk count rate ( $ {{{\alpha }}} \,\, {\times }$ the count rate of 123I) from the uncorrected count rate of 99mTc. To evaluate the measurement accuracy, dual- and single-radioisotope solutions were measured, and the mean percentage error of the measured count rate of dual-radioisotope solutions to that of the single-radioisotope solution was obtained. The energy resolutions full width at half maximum of the CdTe-based well counter were 6.95% and 6.93% at 140.5 keV and 159 keV, respectively, and were higher than that of a conventional NaI (Tl) scintillation detector (10% at 140.5 keV). The count loss in the CdTe detector was 1.7% at 44 kcps. For the dual-radioisotope measurement, the percentage errors (mean percentage% ± standard deviation%, ${N} \,\, {=}$ 3) of the count rate of 99mTc and 123I at a high count rate (99mTc: 44 kcps, 123I: 28 kcps) were −1.9% ± 0.0% and −3.5% ± 1.1%, respectively. On the other hand, the percentage errors of the count rate of 99mTc and 123I at a low count rate (99mTc: 3 kcps, 123I: 4 kcps) were −0.4% ± 0.3% and 0.2% ± 0.6%, respectively. The CdTe-based well counter measured each concentration of 99mTc and 123I in mixed solutions with high accuracy.

Irregular metallic growth at the anode during recharging of batteries can seriously influence the safety of batteries. To address this problem, we have attempted to design active anode materials with anion charge carriers and recently observed the formation and dissolution of an electrochemical film by triflate anions (CF3SO3–) at the surface of magnesium in an ionic liquid (IL) electrolyte of Mg(CF3SO3)2, which represents a rare anode material. The effect of heterogeneous cations on film formation was examined in this work. In an IL that dissolves NaCF3SO3, sodium ions with a lower reduction potential than Mg2+/Mg would not be expected to assist film formation. However, to our surprise, we discovered that some sodium ions are involved in film formation. The sodium ions are believed to act as a cross-linking point for the formation of a film network, which resulted in fairly good reversibility for film formation. In a Ce(CF3SO3)3-IL electrolyte, an electrochemically formed film free of Ce3+was obtained. The trivalent cerium cations were deactivated and transformed to an oxide on Mg metal. However, the reversibility of film formation in the Ce(CF3SO3)3system did not meet the expected level. By coupling the film formation and dissolution behavior with a V2O5cathode, a rechargeable battery was fabricated with dual ion transport species of Na+or Ce3+for the cathode and CF3SO3–for the anode. The unique battery with NaCF3SO3is demonstrated to exhibit good discharge/charge performance with long-term cyclability.

We observed the first electrochemical insertion of Ca2+into Prussian blue analogue, MnFe(CN)6, in nonaqueous solutions of Ca(CF3SO3)2and various solvents including ionic liquid at 60 °C. The kinetics for the Ca2+insertion reaction were studied by cyclic voltammetry, and were compared to those of Na+intercalation. By coupling this phenomenon with metallic anodes, two energy storage devices were made. Ca anode produced a primary cell that operated at a voltage of around 2.0 V. When Mg plate was used as an anode, the negative active material associated with CF3SO3–, which we have already reported was newly formed at the surface of Mg plate. By combining the negative active material, we have fabricated a novel rechargeable battery using dual ion transport species of Ca2+for the cathode and CF3SO3–for the anode, and demonstrated that the battery showed repeated discharge/charge performance.

We have examined anode materials with anions as an ion transport species to solve metal deposition in rechargeable batteries intrinsically. Mg deposition-dissolution tests were conducted using some ionic liquid electrolytes at 60 °C, and a new electrochemical reaction was observed in addition to Mg deposition and dissolution in an electrolyte of Mg(CF3SO3)2and N-methyl-N-propylpiperidinium bis(trifluoromethane sulfonyl)amide. The reaction was determined to be based on the formation and release of a polymeric network of triflate ions (CF3SO3–) on the Mg metal surface, which suggests a novel anode material with anion carriers. An anion battery is also demonstrated using this phenomenon and incorporating an acrylate polymer with 2,2,6,6-tetramethylpiperidine-oxyl side units in the cathode to provide evidence of the rechargeability by the intermediary anion carrier.

This prospective study was aimed to evaluate the effects of surgical revascularization on cerebral oxygen metabolism in moyamoya disease.

PET using semiconductor detectors provides high-quality images of the human brain because of its high spatial resolution. To quantitatively evaluate the delineation of image details in clinical PET images, we used normalized mutual information (NMI) to quantify the similarity with images obtained through MRI. NMI is used to evaluate image quality by determining similarity with a reference image. The aim of this study was to evaluate quantitatively the delineation of image details provided by semiconductor PET.

Clinical features and pathophysiology of postoperative hyperperfusion in moyamoya disease are still unclear. This study was aimed to clarify the incidence and time course of postoperative hyperperfusion and to determine the independent predictors of postoperative hyperperfusion in moyamoya disease.

Cerebral blood flow (CBF) estimation with C15O2PET usually assumes a single tissue compartment model and a fixed brain–blood partition coefficient of water. However, the partition coefficient may change in pathological conditions. The purpose of this study was to investigate the changes in the partition coefficient of water in pathological regions and its effect on regional CBF assessment.

Lithium is clinically available for the treatment of mood disorders. However, it has remained unclear how lithium acts on the brain to produce its effects. The aim of this study was to evaluate the effects of chronic lithium on human brain activity using positron emission tomography and clarify the correlation between brain activity changes and cognitive functional changes as induced by chronic lithium administration. A total of 20 healthy male subjects (mean age, 32 ± 6 years) underwent positron emission tomographic scans with 18F-fluorodeoxyglucose and a battery of neuropsychological tests at baseline condition and after 4 weeks of lithium administration. Brain metabolic data were analyzed using statistical parametric mapping. Lithium increased relative regional cerebral glucose metabolism (rCMRglc) in the bilateral dorsomedial frontal cortices including the anterior cingulate gyrus and decreased rCMRglc in the right cerebellum and left lingual gyrus/cuneus. There was no difference in any of the variables of cognitive functions between the baseline condition and after chronic lithium administration. There was no correlation between rCMRglc changes in any of the brain regions and individual variable changes in any of the neuropsychological tests. The results suggest that the effects of chronic lithium are associated with increased activity in the bilateral dorsomedial frontal cortices including the anterior cingulate gyrus and decreased activity in the right cerebellum and left lingual gyrus/cuneus.

Purpose : It is broadly accepted that the brain control is crucial to maintain the urinary continence. However, the brain system concerned in urine storage remains unclear in human. The aim of this study was to identify the brain regions involved in urine storage in normal subjects. Materials : The study population consisted of 10 male normal volunteers with ages ranging from 27 to 41 years old. All of them were right handed. None of them had suffered from any psychiatric or neurological disorder. Methods : Brain perfusion PET was repeated with O-15 H2O injection under empty bladder and filled bladder following saline infusion with a catheter. In each condition, three scans were obtained for statistical analysis. The data were analyzed using Statistical Mapping Procedure. A corrected P -value under 0.0001 was considered as statistical significant. Results : During urine storage, a significantly activated area was found only in the central part of the midbrain. There is no significant increase in cerebral blood flow in the brain cortex. These data seem to be concordant with the animal experiments. Conclusion : Our PET data indicated that the central part of the midbrain was involved in the urine storage function in the human brain.

Time-resolved fluorescence properties of 9-methylanthracene (9MAn) dispersed in film of polyvinylchloride (PVC) containing carbon black were studied under tensile loadings. The fluorescence lifetime of 9MAn decreased from 5.70 to 5.55 ns, whereas the stresses acting on the films increased from 0 to 3 MPa. The change in fluorescence lifetimes of 9MAn during the stress relaxation process showed that the fluorescence lifetimes were correlated with the stresses, not with the strains. The results suggest that 9MAn is a useful probe for monitoring stresses acting on the matrix. With the use of the fluorescence properties of 9MAn, the residual tensile stresses on the skin-layer of PVC injection-molded test pieces were estimated. The estimated residual stresses were about ~ 1 MPa. The residual stresses were relaxed to 0 MPa with annealing at 100°C. © 2002 John Wiley & Sons, Inc. J Appl Polym Sci 83: 2600–2603, 2002

Several kinds of perceptions, including distention and coldness, arise from the bladder. Information on bladder fullness conveyed by mechanoreceptors within the bladder wall contributes to the basic micturition reflex via the bulbospinal reflex pathway, whereas cold stimulation of the bladder is processed differently. To elucidate the human brain mechanisms of voluntary urine storage and bladder cold perception we performed positron emission tomography scanning to examine brain regions activated by bladder distention or cold stimulation.

Gated myocardial perfusion single-photon emission tomography (SPET) has been used for the measurement of left ventricular (LV) function and validated by means of comparison with other imaging modalities. We have designed a new dynamic myocardial phantom in order to validate the LV function as assessed by the use of gated myocardial perfusion SPET. The phantom consists of two half-ellipsoids (an endocardial surface and an epicardial surface) and a thorax. The myocardial space is filled with a radioactive solution. The endocardial surface moves continuously towards and away from the epicardial surface in the longitudinal axis to vary the LV volume [143 ml at end-diastole (ED), 107 ml at end-systole (ES)] and thickness (apex 8 mm at ED and 26 mm at ES, midplane 8 mm). The mean values of wall motion (WM) for the apical midplane region and the basal midplane region were 5 mm and 2 mm, respectively. Gated myocardial SPET was performed during 8 and 16 intervals. These projection data sets were processed using a Butterworth filter with an order of 5 and a critical frequency of 0.34 cycles/cm. LV function was calculated using the quantitative gated SPET (QGS) algorithm. The LV function values estimated by gated SPET during 16 intervals [22% for ejection fraction (EF), 3.7 mm for WM of the apical midplane, 1.7 mm for WM of the basal midplane] closely resembled actual LV functions [25% for EF, 5 mm for WM of the apical midplane, 2 mm for WM of the basal midplane]. However, the estimated values during 8 intervals were smaller than those during 16 intervals (19% for EF, 3.3 mm for WM of the apical-midplane, 1.1 mm for WM of the basal-midplane). The estimated LV volumes closely correlated with the actual volumes (r=0.99 for 16 intervals,r=0.95 for 8 intervals). Utilizing this phantom, LV function estimated using gated myocardial SPET can be compared with actual values.

Using ionic polymer gel that demonstrated an electric field-associated bending mo tion in aqueous solutions, an electrically driven polymer gel finger has been constructed. The material used for the finger was a hybrid gel of a cylindrical poly(vinyl alcohol)-poly(sodium acrylate) composite gel (PVA-PAA gel) rod and PVA gel film containing sodium carbonate as a skin. The working gel finger has been designed by equipping the PVA gel film of the hybrid gel with two platinum wires as electrodes. When a dc voltage was applied, the finger bent smoothly toward the positive electrode at a relatively high speed in the air. The bending of the finger occurred through a differential swelling of the PVA-PAA gel in the hybrid gel. A prototype of a microrobot hand with two gel fingers has also been designed. The hand grasped or released a piece of paper in response to electric signals.

Steady-state and time-resolved fluorescence properties of poly(N-vinylcarbazole) (PVCz) dispersed in a polystyrene (PS) cast film were studied under tensile loadings at room temperature. The excited monomer emission of PVCz located around 350 nm decreased with increasing applied tensile strain from 0 to 0.8%. The strain enhanced the emission which was ascribed to the partial-overlap excimer of PVCz in a 360–430 nm region. The emission due to the full-overlap excimer of PVCz between 430 and 500 nm was unchanged by the action of the tensile loadings. The ratio of fluorescence intensities at 375 nm and 345 nm I375/I345 was proportional to the applied strain. The time-resolved fluorescence study indicated that the lifetimes of the excited monomer and of the partial-overlap excimer were not affected by the strain. The obtained results mean that the strain applied to the PS matrix increases the partial-overlap conformation of two adjacent carbazolyl chromophores in a PVCz chain and suggest that PVCz is a useful probe for detecting residual strains in polymer matrices. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1569–1573, 1997

The dynamic viscoelasticity of polymeric composites consisting of silicone gel and polymethacrylic acid cobalt(II) salt (PMACo) particles was studied in d.c. electric fields. It was measured by applying sinusoidally varying shear strain or compressive strain to the composites. It was found that the electric fields enhanced the storage and loss moduli of the composites, and changed the loss tangent (electroviscoelastic effect). The amount of the electroviscoelastic effect was influenced by the content of absorbed water in the PMACo particle, the fraction of PMACo particles, and the intensity of the electric field. It also depended on the amplitude and frequency of the applied strain. The increments of the compressive moduli due to the electroviscoelastic effect were much larger than those of the shear moduli.

Fluorescence behavior of poly(3-alkylthiophenes) (P3ATs) in poly(methyl methacrylate) (PMMA) films was studied under tensile loadings. The elastic deformation of the matrix induced by small strains up to 0.2% had a greater influence on time-resolved fluorescence rather than the steady-state one from P3ATs. The decay time of fluorescence decreased linearly as the applied stress was increased, and reached a minimum. We maintained that the attractive phenomenon for the time-resolved fluorescence under the tensile loadings was associated with distortion or deformation of the π-conjugated structure in P3AT chains having large molecular weight. When the applied strain exceeded the elastic limit of the matrix, the time-resolved or steady-state fluorescence behavior was unchanged. However, large elongation over 10% led to the red-shift of the steady-state fluorescence maximum and an increase in the decay time. These fluorescence properties, indicating the growth of the π-conjugation, were mainly governed by strain. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 259–266, 1998

The addition of potassium superoxide (KO2) into the electrolyte for Li-air battery was proved to be an effective screening method to examine the stability of the solvents against superoxide anion radicals (O2*[?]). It was also confirmed that the coupled compound between Li+ and O2*[?], namely LiO2*, was highly reactive for many solvents to decompose themselves. Specific ionic liquid and dimethylsulfoxide, selected solvents by the KO2 screening test, actually performed stable operation of Li-air battery.

The addition of potassium superoxide (KO2) into the electrolyte for Li-air battery was proved to be an effective screening method to examine the stability of the solvents against superoxide anion radicals (O2•−). It was also confirmed that the coupled compound between Li+and O2•−, namely LiO2•, was highly reactive for many solvents to decompose themselves. Specific ionic liquid and dimethylsulfoxide, selected solvents by the KO2screening test, actually performed stable operation of Li-air battery.

The title battery exhibits a very high discharge capacity.

The effect of a hole transport layer on the photoelectrochemical responses from an organic solar cell consisting of a composite polymer film of 5,10,15,20-tetra(3-thienyl)-21H,23H-porphyrin and polythiophene was investigated. The polyalkylthiophene layer that was inserted between the above-described photoactive polymer film and a transparent electrode acted as the hole transport layer. This layer remarkably suppressed the recombination of separated charge carriers generated in the composite polymer film and substantially improved both photocurrent and conversion efficiencies.

The effect of a hole transport layer on the photoelectrochemical responses from an organic solar cell consisting of a composite polymer film of 5,10,15,20-tetra(3-thienyl)-21H,23H-porphyrin and polythiophene was investigated. The polyalkylthiophene layer that was inserted between the above-described photoactive polymer film and a transparent electrode acted as the hole transport layer. This layer remarkably suppressed the recombination of separated charge carriers generated in the composite polymer film and substantially improved both photocurrent and conversion efficiencies.