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1.
ACS Nano ; 17(3): 3135-3142, 2023 Feb 14.
Article in English | MEDLINE | ID: mdl-36669094

ABSTRACT

Magnesium rechargeable batteries (MRBs) promise to be the next post lithium-ion batteries that can help meet the increasing demand for high-energy, cost-effective, high-safety energy storage devices. Early prototype MRBs that use molybdenum-sulfide cathodes have low terminal voltages, requiring the development of oxide-based cathodes capable of overcoming the sulfide's low Mg2+ conductivity. Here, we fabricate an ultraporous (>500 m2 g-1) and ultrasmall (<2.5 nm) cubic spinel MgMn2O4 (MMO) by a freeze-dry assisted room-temperature alcohol reduction process. While the as-fabricated MMO exhibits a discharge capacity of 160 mAh g-1, the removal of its surface hydroxy groups by heat-treatment activates it without structural change, improving its discharge capacity to 270 mAh g-1─the theoretical capacity at room temperature. These results are made possible by the ultraporous, ultrasmall particles that stabilize the metastable cubic spinel phase, promoting both the Mg2+ insertion/deintercalation in the MMO and the reversible transformation between the cubic spinel and cubic rock-salt phases.

2.
Chem Commun (Camb) ; 58(30): 4799, 2022 Apr 12.
Article in English | MEDLINE | ID: mdl-35362017

ABSTRACT

Correction for 'Enhanced ionic conduction in composite polymer electrolytes filled with plant biomass "lignin"' by Zitong Liu et al., Chem. Commun., 2022, DOI: 10.1039/d1cc07148c.

3.
Chem Commun (Camb) ; 58(28): 4504-4507, 2022 Apr 05.
Article in English | MEDLINE | ID: mdl-35302116

ABSTRACT

The addition of a small amount of plant biomass-based lignin causes a large improvement in the ionic conductivity of composite polymer electrolytes at room temperature, which can be fabricated easily in a low carbon way for use in future all-solid-state battery applications.


Subject(s)
Lignin , Polymers , Biomass , Electrolytes , Ions
4.
Soft Matter ; 14(45): 9227-9231, 2018 Nov 21.
Article in English | MEDLINE | ID: mdl-30403253

ABSTRACT

In this article, we propose a thermally responsive shape-memory polymer (SMP) consisting of poly(ethylene carbonate) and non-deteriorated lignin nanoparticles. This SMP was obtained readily by thermal kneading and melt molding without requiring any chemical reaction. The shape-recovering properties of the SMP can be tuned by changing the feed ratio of the components. The estimation of viscoelastic, thermal and mechanical properties of the SMP reveals that the stepwise structural transitions in the SMP rendered a dynamic shape-recovering behavior.

5.
Diabetes Ther ; 9(6): 2399-2406, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30341665

ABSTRACT

INTRODUCTION: Administered basal insulin markedly influences the fasting plasma glucose (FPG) level of individuals with type 1 diabetes. Insulin degludec (IDeg) and insulin glargine U300 (IGlar U300) are now available as ultra-long-acting insulin formulations, but whether or how their glucose-stabilizing effects differ remains unclear. We will compare the effects of these basal insulins on parameters related to blood glucose control, with a focus on day-to-day glycemic variability, in individuals with type 1 diabetes treated with multiple daily injections. METHODS: A multicenter, randomized, open-label, crossover, comparative study (Kobe Best Basal Insulin Study 2) will be performed at 13 participating institutions in Japan. A total of 46 C-peptide-negative adult outpatients with type 1 diabetes will be randomly assigned 1:1 by a centralized allocation process to IGlar U300 (first period)/IDeg (second period) or IDeg (first period)/IGlar U300 (second period) groups, in which subjects will be treated with the corresponding basal insulin for consecutive 4-week periods. The basal insulin will be titrated to achieve an FPG of less than 130 mg/dL initially and then less than 110 mg/dL if feasible. In the last week of each period, plasma glucose will be determined seven times a day by self-monitoring of blood glucose (SMBG) and intraday and day-to-day glucose excursions will be determined by flash glucose monitoring (FGM). The primary end point is comparison of day-to-day glycemic variability as evaluated by the standard deviation (SD) of FPG during the last week of each treatment period. Secondary end points include the coefficient of variance of FPG, the frequency of severe hypoglycemia as evaluated by SMBG, the duration of hypoglycemia as evaluated by FGM, intraday glycemic variability calculated from both SMBG and FGM data, and the administered insulin dose. PLANNED OUTCOMES: The results of the study will be submitted for publication in a peer-reviewed journal to report differences in the effects of two ultra-long-acting basal insulins, IDeg and IGlar U300. CONCLUSION: This head-to-head comparison will be the first study to compare the effects of IDeg and IGlar U300 on day-to-day FPG variability in C-peptide-negative individuals with type 1 diabetes. TRIAL REGISTRATION: Registered in University Hospital Medical Information Network (UMIN) Clinical Trials Registry as 000029630 on 20 June 2017. FUNDING: Novo Nordisk Pharma Ltd.

6.
Macromol Rapid Commun ; 39(14): e1800146, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29748986

ABSTRACT

Electrolytes comprising poly(ethylene carbonate) (PEC)/poly(trimethylene carbonate) (PTM C) with lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) are prepared by a simple solvent casting method. Although PEC and PTMC have similar chemical structures, they are immiscible and two glass transitions are present in the differential scanning calorimetry (DSC) measurements. Interestingly, these two polymers change to miscible blends with the addition of LiTFSI, and the ionic conductivity increases with increasing lithium salt concentration. The optimum composition of the blend electrolyte is achieved at PEC6 PTMC4 , with a conductivity as high as 10-6 S cm-1 at 50 °C. This value is greater than that for single PEC- and PTMC-based electrolytes. Moreover, the thermal stability of the blend-based electrolytes is improved as compared to PEC-based electrolytes. It is clear that the interaction between CO groups and Li+ gives rise to a compatible amorphous phase of PEC and PTMC.


Subject(s)
Dioxanes/chemistry , Electrolytes/chemistry , Polyethylenes/chemistry , Polymers/chemistry , Electric Conductivity , Hydrocarbons, Fluorinated/chemistry , Imides/chemistry , Ions/chemistry , Lithium/chemistry , Temperature
7.
Macromol Rapid Commun ; 38(8)2017 Apr.
Article in English | MEDLINE | ID: mdl-28221711

ABSTRACT

A random copolymer of ethylene oxide with CO2 , namely, poly(ethylene carbonate/ethylene oxide) (P(EC/EO)), has been synthesized as a novel candidate for polymer electrolytes. Electrolyte composed of P(EC/EO) and lithium bis(fluorosulfonyl)imide has an ionic conductivity of 0.48 mS cm-1 and a Li transference number (t+ ) of 0.66 at 60 °C. To study ion-conductive behavior of P(EC/EO)-based electrolytes, the Fourier transform infrared (FT-IR) technique is used to analyze the interactions between Li+ and functional groups of the copolymer. The carbonate groups may interact preferentially with Li+ rather than the ether groups in P(EC/EO). This study suggests that copolymerization of carbonate and flexible ether units can realize both high conductivity and t+ for polymer electrolytes. High-performance P(EC/EO) electrolyte is expected to be a candidate material for use in all-solid-state batteries.


Subject(s)
Electrolytes/chemistry , Polyethylene Glycols/chemistry , Polyethylenes/chemistry , Polymers/chemistry , Carbonates/chemistry , Electric Conductivity , Imides/chemistry , Ions/chemistry , Lithium/chemistry , Molecular Structure , Molecular Weight , Organic Chemicals/chemistry , Spectroscopy, Fourier Transform Infrared , Temperature
8.
ACS Omega ; 2(3): 835-841, 2017 Mar 31.
Article in English | MEDLINE | ID: mdl-31457475

ABSTRACT

In the present study, surface amino-functionalized silica nanofibers (f-SiO2NFs, average diameter = 400 and 1000 nm) are used as one-dimensional (1-D) fillers of ionic liquid (IL)-based quasisolid electrolytes. On adding f-SiO2NFs to an IL (1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide, EMITFSA) containing lithium bis(trifluoromethanesulfonyl)-amide (LiTFSA), the well-dispersed 1-D nanofillers easily form a three-dimensional network structure in the IL, function as physical cross-linkers, and increase the viscosity of the composites, consequently providing a quasisolid state at a 3.5 wt % fraction of the NFs. Rheological measurements demonstrate that the prepared composites exhibit "gel-like" characteristics at 40-150 °C. All prepared composites show high ionic conductivities, on the order of 10-3 S cm-1, around room temperature. To investigate the additive effect of f-SiO2NFs in the composites, the lithium transference numbers are also evaluated. It is found that thinner NFs enhance the transference numbers of the composites. In addition, quasisolid lithium-ion cells containing the prepared composites demonstrate relatively high rate characteristics and good cycling performance at high temperature (125 °C).

9.
Medicine (Baltimore) ; 94(45): e1940, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26559263

ABSTRACT

Cytomegalovirus (CMV)-associated gastroduodenal ulcers (GDU) are a rare digestive disease, which principally affect immunocompromised patients. We recently experienced CMV-associated GDU occurring in a seemingly immunocompetent patient. The rarity of such a condition was inimical to a correct clinical diagnosis.A 77-year-old woman with Alzheimer's disease was admitted to our hospital because of vomiting and anorexia. Her general condition was extremely poor due to severe dehydration. Any invasive procedures including gastroduodenal endoscopy could not be performed. Laboratory test results showed electrolyte imbalance, hyperglycemia, and hypercortisolemia. The plasma adrenocorticotropic hormone level was rather low. On her 11th day in hospital, she suddenly fell into shock status. Despite intensive care, the patient could not be rescued. An autopsy was performed and revealed that she had suffered from CMV-associated GDU and died of candidemia that invaded through the ulcer. Her adrenal glands showed neither neoplasm nor hyperplasia, suggesting that her hypercortisolism was a purely functional disorder. We concluded that the severe opportunistic infections were developed in association with functional hypercortisolism.This case suggests that functional hypercortisolism, even though transient, can cause a patient to be immunocompromised.


Subject(s)
Cushing Syndrome/immunology , Cytomegalovirus Infections/diagnosis , Cytomegalovirus Infections/etiology , Immunocompromised Host , Peptic Ulcer/diagnosis , Peptic Ulcer/etiology , Aged , Female , Humans
10.
Chem Commun (Camb) ; 50(34): 4448-50, 2014 May 04.
Article in English | MEDLINE | ID: mdl-24653996

ABSTRACT

We have found remarkable ion-conductive properties in a novel polymer electrolyte composed of poly(ethylene carbonate) and Li bis-(fluorosulfonyl) imide. The self-diffusion coefficient of Li-ions exceeded 10(-7) cm(2) s(-1) and the Li transference number was estimated to be more than 0.8 in composites filled with only 1 wt% of TiO2 nanoparticles.

11.
Phys Chem Chem Phys ; 15(39): 16626-33, 2013 Oct 21.
Article in English | MEDLINE | ID: mdl-23963202

ABSTRACT

The composite material P(EO/EM)-Sa consisting of synthetic saponite (Sa) dispersed in poly[ethylene oxide-co-2-(2-methoxyethoxy)ethyl glycidyl ether] (P(EO/EM)) is studied by "in situ" measurements using broadband electrical spectroscopy (BES) under pressurized CO2 to characterize the dynamic behavior of conductivity and the dielectric relaxations of the ion host polymer matrix. It is revealed that there are three dielectric relaxation processes associated with: (I) the dipolar motions in the short oxyethylene side chains of P(EO/EM) (ß); and (II) the segmental motion of the main chains comprising the polyether components (αfast, αslow). αslow is attributed to the slow α-relaxation of P(EO/EM) macromolecules, which is hindered by the strong coordination interactions with the ions. Two conduction processes are observed, σDC and σID, which are attributed, respectively, to the bulk conductivity and the interdomain conductivity. The temperature dependence of conductivity and relaxation processes reveals that αfast and αslow are strongly correlated with σDC and σID. The "in situ" BES measurements under pressurized CO2 indicate a fast decrease in σDC at the initial CO2 treatment time resulting from the decrease in the concentration of polyether-M(n+) complexes, which is driven by the CO2 permeation. The relaxation frequency (fR) of αslow at the initial CO2 treatment time increases and shows a steep rise with time with the same behavior of the αfast mode. It is demonstrated that the interactions between polyether chains of P(EO/EM) and cations in the polymer electrolyte layers embedded in Sa are probably weakened by the low permittivity of CO2 (ε = 1.08). Thus, the formation of ion pairs in the polymer electrolyte domains of P(EO/EM)-Sa occurs, with a corresponding reduction in the concentration of ion carriers.

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