Solubilization of single-walled carbon nanotubes by entanglements between them and hyperbranched phenolic polymer

金沢大学理工研究域物質化学系Hyperbranched phenolic polymer (HBP) was prepared by Lewis acid-catalyzed polycondensation of bifunctional phenolic monomer with trifunctional phenolic monomer. By choosing an appropriate Lewis acid, HBP was successfully obtained. By using physical adsorption of HBP on a single-walled carbon nanotube (SWCNT) surface, solubilization of SWCNTs was examined. SWCNTs were soluble with extended branches of HBP in N,N-dimethylformamide (DMF) solution, while they were insoluble in a linear phenolic polymer. In the presence of shrinking branches of HBP in tetrahydrofuran, SWCNTs were hardly soluble. Entanglements between extended branches of HBP and SWCNT in DMF solution resulted in high solubility of SWCNTs. © 2008 Elsevier Ltd. All rights reserved

Defection-selective solubilization and chemically-responsive solubility switching of single-walled carbon nanotubes with cucurbit[7]uril

金沢大学理工研究域物質化学系Single-walled carbon nanotubes (SWCNTs) were suspended in aqueous media with cucurbit[7]uril (CB7), while SWCNTs were insoluble with cucurbit[5]uril (CB5). Moreover, defection-selective solubilization of SWCNTs with CB7 was demonstrated. © The Royal Society of Chemistry

The carbonization of aromatic molecules with three-dimensional structures affords carbon materials with controlled pore sizes at the Ångstrom-level

分子構造により細孔径を制御したカーボンを開発. 京都大学プレスリリース. 2021-05-24.Carbon materials with controlled pore sizes at the nanometer level have been obtained by template methods, chemical vapor desorption, and extraction of metals from carbides. However, to produce porous carbons with controlled pore sizes at the Ångstrom-level, syntheses that are simple, versatile, and reproducible are desired. Here, we report a synthetic method to prepare porous carbon materials with pore sizes that can be precisely controlled at the Ångstrom-level. Heating first induces thermal polymerization of selected three-dimensional aromatic molecules as the carbon sources, further heating results in extremely high carbonization yields (>86%). The porous carbon obtained from a tetrabiphenylmethane structure has a larger pore size (4.40 Å) than those from a spirobifluorene (4.07 Å) or a tetraphenylmethane precursor (4.05 Å). The porous carbon obtained from tetraphenylmethane is applied as an anode material for sodium-ion battery

CPL on/off control of an assembled system by water soluble macrocyclic chiral sources with planar chirality

Herein, we report the synthesis and planar chiral properties of a pair of water-soluble cationic pillar[5]arenes with stereogenic carbons. Interestingly, although units of the molecules were rotatable, only one planar chiral diastereomer existed in water in both cases. As a new type of chiral source, these molecules transmitted chiral information from the planar chiral cavities to the assembly of a water-soluble extended π-conjugated compound, affording circularly polarized luminescence (CPL). The chirality transfer process and resulting CPL were extremely sensitive to the feed ratio of the chiral pillar[5]arenes owing to the combined action of their planar chirality, bulkiness, and strong binding properties. When a limited amount of chiral source was added, further assembly of the extended π-conjugated compound into helical fibers with CPL was triggered. Unexpectedly, larger amounts of chiral source destroyed the helical fiber assemblies, resulting in elimination of the chirality and CPL properties from the assembled structures

Changes in lipoprotein lipase and endothelial lipase mass in familial hypercholesterolemia during three-drug lipid-lowering combination therapy.

Background: This study was performed to compare the effects of three different lipid-lowering therapies (statins, ezetimibe, and colestimide) on lipoprotein lipase and endothelial lipase masses in pre-heparin plasma (pre-heparin LPL and EL mass, respectively) from patients with familial hypercholesterolemia (FH). FH is usually treated by coadministration of these three drugs. Methods: The pre-heparin LPL and EL masses were measured in fresh frozen plasma drawn and stored at various time points during coadministration of the three drugs from patients with heterozygous FH harboring a single mutation in the LDL receptor (n = 16, mean age 63 years). The patients were randomly divided into two groups based on the timing when ezetimibe was added. Results: Plasma LPL mass concentration was significantly reduced by rosuvastatin at 20 mg/day (median = 87.4 [IQR: 71.4-124.7] to 67.5 [IQR: 62.1-114.3] ng/ml, P < 0.05). In contrast, ezetimibe at 10 mg/day as well as colestimide at 3.62 g/day did not alter its level substantially (median = 67.5 [IQR: 62.1-114.3] to 70.2 [IQR: 58.3-106.2], and to 74.9 [IQR: 55.6-101.3] ng/ml, respectively) in the group starting with rosuvastatin followed by the addition of ezetimibe and colestimide. On the other hand, the magnitude in LPL mass reduction was lower in the group starting with ezetimibe at 10 mg/day before reaching the maximum dose of 20 mg/day of rosuvastatin. Plasma EL mass concentration was significantly increased by rosuvastatin at 20 mg/day (median = 278.8 [IQR: 186.7-288.7] to 297.0 [IQR: 266.2-300.2] ng/ml, P < 0.05), whereas other drugs did not significantly alter its level. Conclusion: The effects on changes of LPL and EL mass differed depending on the lipid-lowering therapy, which may impact the prevention of atherosclerosis differently. © 2016 Tada et al

Pulmonary hypertension associated with veno-occlusive disease in systemic sclerosis: Insight into the mechanism of resistance to vasodilator

We report a case with pulmonary veno-occlusive disease (PVOD) associated with systemic sclerosis which exhibits strong resistance to pulmonary vasodilator.A 55-year-old female with severe pulmonary hypertension was admitted to our hospital to be introduced to epoprostenol infusion therapy. She was diagnosed as having pulmonary arterial hypertension (PAH) associated with systemic sclerosis at the age of 51. Several aggressive treatments with pulmonary vasodilators, including oral prostaglandin, endothelin receptor antagonists, and phosphodiesterase 5 inhibitors, failed to improve her symptoms. We introduced continuous intravenous epoprostenol therapy from 2. μg/kg/min for her. However, pulmonary edema appeared and worsened in a dose-dependent manner. We made a diagnosis of PVOD clinically at that time. Thereafter, pulmonary edema gradually disappeared consistent with the reduction of the dose of epoprostenol infusion. She died of renal failure and infection 4. months after the introduction of epoprostenol infusion therapy. A histological examination revealed severe stenosis and occlusions of pulmonary veins as well as pulmonary arteries over a wide area. We suggest that prevalence of veno-occlusive type of disease could be one of the major mechanisms of less responsive or even refractory to pulmonary vasodilator therapies in patients with PAH associated with connective tissue disease. © 2011 Japanese College of Cardiology

Pillar[6]arene acts as a biosensor for quantitative detection of a vitamin metabolite in crude biological samples

ビタミン代謝物を迅速定量できる超分子バイオセンサーを開発. 京都大学プレスリリース. 2020-12-09.Metabolic syndrome is associated with obesity, hypertension, and dyslipidemia, and increased cardiovascular risk. Therefore, quick and accurate measurements of specific metabolites are critical for diagnosis; however, detection methods are limited. Here we describe the synthesis of pillar[n]arenes to target 1-methylnicotinamide (1-MNA), which is one metabolite of vitamin B3 (nicotinamide) produced by the cancer-associated nicotinamide N-methyltransferase (NNMT). We found that water-soluble pillar[5]arene (P5A) forms host–guest complexes with both 1-MNA and nicotinamide, and water-soluble pillar[6]arene (P6A) selectively binds to 1-MNA at the micromolar level. P6A can be used as a “turn-off sensor” by photoinduced electron transfer (detection limit is 4.38 × 10−6 M). In our cell-free reaction, P6A is used to quantitatively monitor the activity of NNMT. Moreover, studies using NNMT-deficient mice reveal that P6A exclusively binds to 1-MNA in crude urinary samples. Our findings demonstrate that P6A can be used as a biosensor to quantify 1-MNA in crude biological samples

Assessment of Coronary atherosclerosis in patients with familial hypercholesterolemia by coronary computed tomography angiography

The aims of this study were (1) to determine whether the accumulation of coronary plaque burden assessed with coronary computed tomography angiography (CCTA) can predict future events and (2) to estimate the onset and progression of coronary atherosclerosis in patients with familial hypercholesterolemia (FH). Consecutive 101 Japanese patients with heterozygous FH (men= 52, mean age 56 ± 16years, mean low-density lipoprotein cholesterol 264 ± 58mg/dl) who underwent 64-detector row CCTA without known coronary artery disease were retrospectively evaluated by assigning a score (0 to 5) to each of 17 coronary artery segments according to the Society of Cardiovascular Computed Tomography guidelines. Those scores were summed and subsequently natural log transformed. The periods to major adverse cardiac events (MACE) were estimated using multivariable Cox proportional hazards models. During the follow-up period (median 941days), 21 MACE had occurred. Receiver operating characteristic curve analyses identified a plaque burden score of 3.35 (raw score 28.5) as the optimal cutoff for predicting a worse prognosis. Multivariate Coxregression analysis identified the presence of a plaque score ≥3.35 as a significant independent predictor of MACE (hazard ratio= 3.65; 95% confidence interval 1.32 to 25.84, p<0.05). The regression equations were Y= 0.68. X- 15.6 (r= 0.54, p <0.05) in male and Y= 0.74. X- 24.8 (r= 0.69, p <0.05) in female patients with heterozygous FH. In conclusion, coronary plaque burden identified in a noninvasive, quantitative manner was significantly associated with future coronary events in Japanese patients with heterozygous FH and that coronary atherosclerosis may start to develop, on average, at age 23 and 34years in male and female patients with heterozygous FH, respectively