Polythioethers bearing side groups for efficient degradation by E1cB reaction : reaction design for polymerization and main-chain scission

We have previously reported the polycondensation by the tandem reactions of dithiols and α-(bromomethyl)acrylates, consisting of conjugate substitution (SN2′ reaction) and conjugate addition (Michael addition) reactions. The resulting polythioethers underwent a main-chain scission (MCS) by E1cB reaction, which is the reverse reaction of conjugate addition, although it was not quantitative due to the equilibrium. Herein, the modification of the structures of polythioethers led to irreversible MCS, whereby the β-positions of ester moieties were substituted with a phenyl group. This slight modification in the polymer structure influenced the monomer structures and polymerization mechanisms. The understanding of reaction mechanisms by model reactions was required to obtain high molecular weights of polythioethers. It was clarified that the consequent additions of 1,4-diazabicyclo[2.2.2]octane (DABCO), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and PBu3 were effective to achieve high molecular weight. The resulting polythioethers decomposed by irreversible MCS via E1cB reaction with DBU

Theoretical Analysis on the Stability of 1-Pyrenebutanoic Acid Succinimidyl Ester Adsorbed on Graphene

Oishi Y., Ogi H., Hagiwara S., et al. Theoretical Analysis on the Stability of 1-Pyrenebutanoic Acid Succinimidyl Ester Adsorbed on Graphene. ACS Omega 7, 31120 (2022); https://doi.org/10.1021/acsomega.2c03257.The adsorbed structure of 1-pyrenebutanoic acid succinimidyl ester (PASE) on graphene was investigated based on density functional theory. We found two locally stable structures: A straight structure with the chainlike part of butanoic acid succinimidyl ester (BSE) lying down and a bent structure with the BSE part directed away from graphene, keeping the pyrene (Py) part adsorbed on graphene. Then, to elucidate the adsorption mechanism, we separately estimated the contributions of the Py and BSE parts to the entire PASE adsorption, and the adsorption effect of the BSE part was found to be secondary in comparison to the contribution of the Py. Next, the mobility of the BSE part at room temperature was confirmed by the activation energy barrier between straight and bent structures. To take account of the external environment, we considered the presence of amino acids and the hydration effect by a three-dimensional reference interaction site model. The contributions of glycine molecules and the solvent environment to stabilizing the bent PASE structure relative to the straight PASE structure were found. Therefore, the effect of the external environment around PASE is of importance when the standing-up process of the BSE part from graphene is considered

Crystalline maricite NaFePO₄ as a positive electrode material for sodium secondary batteries operating at intermediate temperature

Maricite NaFePO₄ (m-NaFePO₄) was investigated as a positive electrode material for intermediate-temperature operation of sodium secondary batteries using ionic liquid electrolytes. Powdered m-NaFePO₄ was prepared by a conventional solid-state method at 873 K and subsequently fabricated in two different conditions; one is ball-milled in acetone and the other is re-calcined at 873 K after the ball-milling. Electrochemical properties of the electrodes prepared with the as-synthesized m-NaFePO₄, the ball-milled m-NaFePO₄, and the re-calcined m-NaFePO₄ were investigated in Na[FSA]-[C₂C₁im][FSA] (C₂C₁im⁺ = 1-ethyl-3-methylimidazolium, FSA⁻ = bis(fluorosulfonyl)amide) ionic liquid electrolytes at 298 K and 363 K to assess the effects of temperature and particle size on their electrochemical properties. A reversible charge-discharge capacity of 107 mAh g⁻¹ was achieved with a coulombic efficiency >98% from the 2nd cycle using the ball-milled m-NaFePO₄ electrode at a C–rate of 0.1 C and 363 K. Electrochemical impedance spectroscopy using m-NaFePO₄/m-NaFePO₄ symmetric cells indicated that inactive m-NaFePO₄ becomes an active material through ball-milling treatment and elevation of operating temperature. X-ray diffraction analysis of crystalline m-NaFePO₄ confirmed the lattice contraction and expansion upon charging and discharging, respectively. These results indicate that the desodiation-sodiation process in m-NaFePO₄ is reversible in the intermediate-temperature range

B→ϕKsB\to \phi K_s versus Electric Dipole Moment of 199^{199}Hg Atom in Supersymmetric Models with Right-handed Squark Mixing

The correlation between the CP asymmetry in $B\to \phi K_s$ ($S_{\phi K_s}$) and the chromoelectric dipole moment (CEDM) of strange quark ($d_s^C$), which is constrained by the electric dipole moment (EDM) of $^{199}$Hg, is studied in the supersymmetric (SUSY) models with the right-handed squark mixing. It is known that, if the right-handed bottom and strange squarks have a CP-violating mixing, such as in the SUSY SU(5) GUT with right-handed neutrinos, the induced gluon-penguin diagram may give a sizable contribution to $S_{\phi K_s}$. However, when the left-handed bottom and strange squarks also have a mixing, the conspiracy of the left and right-handed squarks may lead to a sizable $d_s^C$, which is enhanced by $m_b/m_s$. While the estimate for the EDM of $^{199}$Hg, induced by $d^C_s$, might have large uncertainties due to the hadron and nuclear dynamics, the current bound implies the gluon penguin contribution by the right-handed squarks to $S_{\phi K_s}$ should be suppressed and the deviation of $S_{\phi K_s}$ from the Standard Model may not be so large. Also, we discuss the constraint from the EDM of $^{199}$Hg in the SUSY SU(5) GUT with the right-handed neutrinos.Comment: 11 pages, 1 figure, version to appear in PL

Long-term prognosis of diabetic patients with acute myocardial infarction in the era of acute revascularization

Abstract Background The long-term prognosis of diabetic patients with acute myocardial infarction (AMI) treated by acute revascularization is uncertain, and the optimal pharmacotherapy for such cases has not been fully evaluated. Methods To elucidate the long-term prognosis and prognostic factors in diabetic patients with AMI, a prospective, cohort study involving 3021 consecutive AMI patients was conducted. All patients discharged alive from hospital were followed to monitor their prognosis every year. The primary endpoint of the study was all-cause mortality, and the secondary endpoint was the occurrence of major cardiovascular events. To elucidate the effect of various factors on the long-term prognosis of AMI patients with diabetes, the patients were divided into two groups matched by propensity scores and analyzed retrospectively. Results Diabetes was diagnosed in 1102 patients (36.5%). During the index hospitalization, coronary angioplasty and coronary thrombolysis were performed in 58.1% and 16.3% of patients, respectively. In-hospital mortality of diabetic patients with AMI was comparable to that of non-diabetic AMI patients (9.2% and 9.3%, respectively). In total, 2736 patients (90.6%) were discharged alive and followed for a median of 4.2 years (follow-up rate, 96.0%). The long-term survival rate was worse in the diabetic group than in the non-diabetic group, but not significantly different (hazard ratio, 1.20 [0.97-1.49], p = 0.09). On the other hand, AMI patients with diabetes showed a significantly higher incidence of cardiovascular events than the non-diabetic group (1.40 [1.20-1.64], p Conclusions Although diabetic patients with AMI have more frequent adverse events than non-diabetic patients with AMI, the present results suggest that acute revascularization and standard therapy with aspirin and RAS inhibitors may improve their prognosis.</p

Revisiting Signature of Minimal Gauge Mediation

We revisit phenomenology of the minimal gauge-mediated model. This model is motivated from the SUSY CP and flavor problems. A specific feature of this model is that \tan\beta is naturally large, since the B term in the Higgs potential is zero at the messenger scale. This leads to significant SUSY contributions to various low-energy observables. We evaluate the anomalous magnetic moment of the muon and the branching ratio of \bar{B}\to X_s\gamma taking account of recent theoretical and experimental developments. We find that the current experimental data prefer a low messenger scale (\sim 100 TeV) and gluino mass around 1 TeV. We also calculate the branching ratios of \bar{B}\to X_s l^+l^-, B_s\to \mu^+\mu^-, and B^-\to \tau^- \bar{\nu}, and show that these observables are strongly correlated with each other in this model.Comment: 20 pages, 16 figure

CLASSIFICATION OF BIPOLAR DISORDER, MAJOR DEPRESSIVE DISORDER, AND HEALTHY STATE USING VOICE

Objective: In this study, we propose a voice index to identify healthy individuals, patients with bipolar disorder, and patients with major depressive disorder using polytomous logistic regression analysis.Methods: Voice features were extracted from voices of healthy individuals and patients with mental disease. Polytomous logistic regression analysis was performed for some voice features.Results: With the prediction model obtained using the analysis, we identified subject groups and were able to classify subjects into three groups with 90.79% accuracy.Conclusion: These results show that the proposed index may be used as a new evaluation index to identify depression

Structural modification by adding Li cations into Mg/Cs-TFSA molten salt facilitating Mg electrodeposition

Free volume around Mg ions in Li/Mg/Cs-TFSA by adding Li cations would facilitate the Mg electrodeposition, which has been studied by Raman spectroscopy, high-energy X-ray diffraction, and reverse Monte Carlo structural refinement using molecular mechanics.</p

Amino Acid Synthesis in a Supercritical Carbon Dioxide - Water System

Mars is a CO2-abundant planet, whereas early Earth is thought to be also CO2-abundant. In addition, water was also discovered on Mars in 2008. From the facts and theory, we assumed that soda fountains were present on both planets, and this affected amino acid synthesis. Here, using a supercritical CO2/liquid H2O (10:1) system which mimicked crust soda fountains, we demonstrate production of amino acids from hydroxylamine (nitrogen source) and keto acids (oxylic acid sources). In this research, several amino acids were detected with an amino acid analyzer. Moreover, alanine polymers were detected with LC-MS. Our research lights up a new pathway in the study of life’s origin