イオン液体を溶媒とする高強度ゲルの合成と構造解析

University of Tokyo (東京大学

Characteristic exothermic behavior and short-range ordering in aggregates of ultimately fine fibers made of monodisperse polystyrene

We investigated the thermal behavior and structure formation of electrospun (ES) fiber mats and freeze-dried (FD) foams consisting of very fine fibrous network structure, and compared the results with those of self-standing membranes, in which the motion of boundary molecules is not restrained by contacting solids. We chose monodisperse polystyrene (PS) as a material polymer to examine the molecular weight effect as well. For the ES fibers and FD foams, a characteristic exothermic peak was observed at around 110 °C in DSC curve at 1st scan, while such exothermic peak did not appear for the self-standing films and bulk. To further investigate the nano-periodic structure inside materials during heating, we carried out WAXD measurements. Although the PS used in this study was atactic, the ES fibers formed ordered structure near its glass-transition temperature (Tg). Furthermore, the FD foams exhibited high short-range order even in the unheated state, and the regularity was more developed by heating above 120 °C

Small-Angle Neutron Scattering Study on Defect-Controlled Polymer Networks

Tetra-PEG gels are classified to near-“ideal” networks with significantly low inhomogeneities, which were confirmed by small-angle neutron scattering (SANS). In this study, we systematically introduced two types of defects into Tetra-PEG gels and investigated effects of defects on structure. First, we prepared defect-rich networks by simply reducing prepolymer concentration, and observed the evolution of network structure by time-resolved SANS during gelation process. In this case, both the scattering intensity and the correlation length increased with reaction time in the ϕ < ϕ* region, while they scarcely changed in the ϕ > ϕ* region. Here, ϕ and ϕ* are the polymer volume fractions at observation and that at chain-overlap concentration, respectively. Second, we prepared “<i>p</i>-tuned” Tetra-PEG gels by tuning the reaction probability, <i>p</i>, and soaked them in water to expose the inhomogeneities. It was revealed that SANS profiles of as-prepared gels did not change noticeably, while those of swollen gels systematically changed with decreasing <i>p</i>. On the basis of these results, we discuss the relationship between the defects of polymer network and inhomogeneities by using simple schematic pictures of polymer network

Structural Study on the UCST-Type Phase Separation of Poly(<i>N</i>‑isopropylacrylamide) in Ionic Liquid

Upper critical solution temperature (UCST)-type phase separation behavior and its conformational change of well-defined poly­(<i>N</i>-isopropylacrylamide) (pNIPAm) in deuterated room-temperature ionic liquid (IL), 1-ethyl-3-methylimidazolium bis­(trifluoromethanesulfonyl)­amide (<i>d</i>₈-[C₂mIm⁺]­[TFSA^–]), were investigated by means of dynamic light scattering (DLS) and small-angle neutron scattering (SANS) measurements. From the temperature dependence of time-averaged scattering intensity obtained by DLS, it was found that the cloud points of pNIPAm/<i>d</i>₈-[C₂mIm⁺]­[TFSA^–] solutions increased with molecular weight (<i>M</i>_w) and concentration. In addition, it was found that there are two relaxation modes of pNIPAm in the IL solutions. From SANS measurements, the radius of gyration, <i>R</i>_g, and the Flory–Huggins interaction parameter, χ, were evaluated as a function of temperature during the phase separation

Empagliflozin in Patients with Chronic Kidney Disease

Background The effects of empagliflozin in patients with chronic kidney disease who are at risk for disease progression are not well understood. The EMPA-KIDNEY trial was designed to assess the effects of treatment with empagliflozin in a broad range of such patients. Methods We enrolled patients with chronic kidney disease who had an estimated glomerular filtration rate (eGFR) of at least 20 but less than 45 ml per minute per 1.73 m(2) of body-surface area, or who had an eGFR of at least 45 but less than 90 ml per minute per 1.73 m(2) with a urinary albumin-to-creatinine ratio (with albumin measured in milligrams and creatinine measured in grams) of at least 200. Patients were randomly assigned to receive empagliflozin (10 mg once daily) or matching placebo. The primary outcome was a composite of progression of kidney disease (defined as end-stage kidney disease, a sustained decrease in eGFR to &lt; 10 ml per minute per 1.73 m(2), a sustained decrease in eGFR of &amp; GE;40% from baseline, or death from renal causes) or death from cardiovascular causes. Results A total of 6609 patients underwent randomization. During a median of 2.0 years of follow-up, progression of kidney disease or death from cardiovascular causes occurred in 432 of 3304 patients (13.1%) in the empagliflozin group and in 558 of 3305 patients (16.9%) in the placebo group (hazard ratio, 0.72; 95% confidence interval [CI], 0.64 to 0.82; P &lt; 0.001). Results were consistent among patients with or without diabetes and across subgroups defined according to eGFR ranges. The rate of hospitalization from any cause was lower in the empagliflozin group than in the placebo group (hazard ratio, 0.86; 95% CI, 0.78 to 0.95; P=0.003), but there were no significant between-group differences with respect to the composite outcome of hospitalization for heart failure or death from cardiovascular causes (which occurred in 4.0% in the empagliflozin group and 4.6% in the placebo group) or death from any cause (in 4.5% and 5.1%, respectively). The rates of serious adverse events were similar in the two groups. Conclusions Among a wide range of patients with chronic kidney disease who were at risk for disease progression, empagliflozin therapy led to a lower risk of progression of kidney disease or death from cardiovascular causes than placebo