Effects of alcohols on emission spectra of toluene-triethylamine mixtures in THF: separation into polar and hydrogen-bonding interactions

The emission spectra of toluene (T)–triethylamine (TEA) systems were measured under conditions of steady-state illumination in some protic and aprotic solvent–THF mixtures. The fluorescence spectrum of the T–TEA system in THF could be separated into three component bands (band A at 279 nm (fluorescence of T), band B at 336 nm (fluorescence of TEA) and band C at 373 nm (emission from an intermolecular exciplex)). The intensities of bands B and C decreased with increasing solvent polarity. The decrease in the intensities of bands B and C is considered to be caused by the enhanced conversion of the exciplex to an ion-pair with increase in solvent polarity. The intensities of bands B and C also decreased owing to the hydrogen-bonding interaction between TEA and protic solvents, but in this case the intensity of band A increased. Acetonitrile only has a polar effect and trichloroacetic acid only has a hydrogen-bonding (or protonation) effect, while alcohols have both effects. The equilibrium constants for the formation of intermolecular hydrogen-bonded complexes of TEA with alcohols were estimated from the changes in the intensity of band A. The hydrogen-bonding and polar effects of alcohols on the intensities of bands B and C could be evaluated separately. The ratio of the hydrogen-bonding effect to the polar effect of alcohols was observed to increase with increasing vol.% of alcohol.</p

Separation into polar and hydrogen-bonding factors of the effects of alcohols on the emission spectrum of 4-phenyl-1-N,N-dimethylaminobutane in THF

The effects of the additions of protic and aprotic polar solvents on the emission spectrum of 4-phenyl-1-N,N-dimethylaminobutane (PDAB) in THF have been studied under conditions of steady-state illumination. The fluorescence spectrum of PDAB in THF was reported to consist of three component bands (band A at 285 nm (fluorescence of the phenyl group), band B at 343 nm (fluorescence of the amino group) and band C at 385 nm (emission from an intramolecular exciplex)). The intensities of bands B and C decreased with increasing solvent polarity. They also decreased owing to the hydrogen-bonding interaction between the amino group in PDAB and protic solvents, but in this case the intensity of band A was found to increase. Acetonitrile has only a polar effect and trichloroacetic acid only a hydrogen-bonding (or protonation) effect, while alcohols have both effects. The equilibrium constants for the formation of intermolecular hydrogen-bonded complexes of the amino group with alcohols were estimated from the intensity change of band A. The hydrogen-bonding and polar effects of alcohols on the intensities of bands B and C could be separately evaluated. The decrease in the intensities of bands B and C with increasing solvent polarity in THF-AN and THF-alcohol mixtures is considered to be caused by the conversion of the exciplex to an ion-pair enhanced by the increase in solvent polarity.</p

Effect of anti-attention-deficit hyperactivity disorder (ADHD) medication on clinical seizures and sleep EEG : A retrospective study of Japanese children with ADHD

Publisher Copyright: © 2021 The Authors. Neuropsychopharmacology Reports published by John Wiley & Sons Australia, Ltd on behalf of The Japanese Society of Neuropsychopharmacology.Aims: Patients with attention-deficit hyperactivity disorder (ADHD) often exhibit basic or paroxysmal wave abnormalities on electroencephalography (EEG). Methylphenidate (MPH), an anti-ADHD stimulant, has been reported to lower the seizure threshold. However, there have been no reports comparing EEG changes before and after administration of the central nervous system (CNS) stimulant MPH, or atomoxetine (ATX) hydrochloride, a non-CNS stimulant. In this study, we investigated changes in sleep EEG before and after the administration of ADHD treatment drugs. Method: With the approval of the ethics committee, the medical records of 28 children with ADHD (23 men and 5 women) who gave consent were retrospectively investigated. The appearance of sudden abnormal waves during a 10-minute sleep EEG recording was measured in 0.1-second units, and the duration of these waves was calculated as the paroxysmal index (PI). Results: Paroxysmal index did not differ significantly between patients who received MPH and those who received ATX. In addition, there were no exacerbations of clinical seizures. Conclusion: It was concluded that ADHD medications do not have an adverse effect on epileptic seizures or abnormal sleep EEGs.Peer reviewe

High-temperature creep strength and room-temperature fracture toughness of MoSiBTiC alloy

Quite recently, the author and his coworkers have developed a new high-temperature material based on Mo-Si-B alloys with TiC addition for ultrahigh temperature applications. The alloys are produced not by powder sintering but by casting, and the constituent phases are of Mo solid solution, Mo5SiB2 (T2), (Ti, Mo)C and (Mo, Ti)2C. The density is reduced to less than 9.0 g/cm3, which is comparable to that of Ni-base superalloys. The high-temperature compressive strength is much stronger than that of commercial heat-resistant molybdenum alloys such as TZM and MHC in a wide high-temperature range. In this paper, the recent progress of our research and development of the MoSiBTiC alloys is reviewed focusing on high-temperature creep strength and room temperature fracture toughness. The alloy having a primary phase during solidification of (Ti, Mo)C and thus a higher (Ti, Mo)C volume fraction was examined for tensile creep properties, and it was found that the alloy showed typical tensile creep curves accompanying transient, steady-state and acceleration creep stages in all the test conditions. The creep strength was relatively good, for example, the rupture time at 1350 °C under 170 MPa was about 750 h. The stress exponents, n, in the temperature range of 1400 – 1600 °C and the stress range of 100 – 300 MPa were ≈ 3 while it was 5 – 6 at 1350 °C, suggesting that the rate-controlling process of creep deformation is different between at and below 1350 °C and at and above 1400 °C in the stress range. Room-temperature fracture toughness of the MoSiBTiC alloys was measured by three-point or four-point bending tests using Chevron-notched specimens. The alloy having the primary phase of (Ti, Mo)C showed the fracture toughness value of better than 15 MPa(m)1/2 at room temperature. The value was better than that of the alloy having a primary phase of Moss and thus a higher Moss volume fraction. The obtained results indicated that (Ti, Mo)C phase works for improving not only high-temperature strength but also room-temperature fracture toughness

Secreted Phospholipase PLA2G2D Contributes to Metabolic Health by Mobilizing ω3 Polyunsaturated Fatty Acids in WAT

Polyunsaturated fatty acids (PUFAs) confer health benefits by preventing inflammation and obesity and by increasing thermogenesis in brown and beige adipocytes. As well as being supplied exogenously as nutrients, PUFAs are largely stored in membrane glycerophospholipids and released by phospholipase A2s (PLA2s). However, the molecular identity of the PLA2 subtype(s) that supplies endogenous PUFAs for metabolic homeostasis remains unclear. Here we show that PLA2G2D, a secreted PLA2 isoform, is constitutively expressed in M2-type macrophages in white adipose tissue (WAT) and shows a reciprocal correlation with obesity. Studies using global and macrophage-specific Pla2g2d-deficient mice reveal that PLA2G2D increases energy expenditure and thermogenesis by facilitating adipocyte browning, thereby ameliorating diet-induced obesity, insulin resistance, and WAT inflammation. Mechanistically, PLA2G2D constitutively supplies a pool of PUFAs, ω3 in particular, in WAT. Thus, our present findings underscore the contribution of the macrophage-driven PLA2G2D-ω3 PUFA axis to metabolic health