SYNTHESES AND PROPERTIES OF COPPER HYDROXIDE NANOSHEETS AND CONTROLLED DEPOSITION

In this study, we synthesized copper hydroxide nanosheet and investigated its electrochemical property and how to deposit it with a uniform amount. The precursor of the nanosheet was a layered copper hydroxide synthesized by the ion exchange of dodecylbenzene sulfonate with acetate in Cu2(OH)3(CH3COO)·H2O. The nanosheet was prepared by delamination of the layered copper hydroxide by dispersion in 1-butanol. Atomic force microscopy images of the nanosheets showed lateral dimensions of ca. 2 μm with the height of ca. 4.5 nm. Cyclic voltammogram of the nanosheet in basic solution showed two cathodic peaks and two anodic peaks similar to copper oxide electrode. To deposit the nanosheet, a quartz glass slide was dipped in the dispersion of the nanosheet in 1-butanol and dried after washing. This procedure was repeated and the ultraviolet and visible light absorption spectrum of the slide was measured. The absorbance of the slide increased in direct proportion to the number of times of the dip-and-dry procedure. Thus we confirmed that controlled amount of nanosheet was deposited on the quartz glass

Assessment of Lower-limb Vascular Endothelial Function Based on Enclosed Zone Flow-mediated Dilation

This paper proposes a novel non-invasive method for assessing the vascular endothelial function of lower-limb arteries based on the dilation rate of air-cuff plethysmograms measured using the oscillometric approach. The principle of evaluating vascular endothelial function involves flow-mediated dilation. In the study conducted, blood flow in the dorsal pedis artery was first monitored while lower-limb cuff pressure was applied using the proposed system. The results showed blood flow was interrupted when the level of pressure was at least 50 mmHg higher than the subject’s lower-limb systolic arterial pressure and that blood flow velocity increased after cuff release. Next, values of the proposed index, %ezFMDL, for assessing the vascular endothelial function of lower-limb arteries were determined from 327 adult subjects: 87 healthy subjects, 150 subjects at high risk of arteriosclerosis and 90 patients with cardiovascular disease (CAD). The mean values and standard deviations calculated using %ezFMDL were 30.5 ± 12.0% for the healthy subjects, 23.6 ± 12.7% for subjects at high risk of arteriosclerosis and 14.5 ± 15.4% for patients with CAD. The %ezFMDL values for the subjects at high risk of arteriosclerosis and the patients with CAD were significantly lower than those for the healthy subjects (p < 0.01). The proposed method may have potential for clinical application.This work was supported by JSPS KAKENHI Grant Number 16K21076

Determination of Acid Dissociation Constants of Hydrochlorothiazide and Its Degradant through Measurement of the Effective Electrophoretic Mobilities in CZE

チアジド系利尿剤の一つであるヒドロクロロチアジドは水中で加水分解により徐々に4-アミノ-6-クロロ-m-ベンゼンジスルホンアミドを生成する．酸解離定数（pKa）などの物理化学定数の決定において分解生成物等の存在は好ましくないが，キャピラリーゾーン電気泳動法では分解生成物を分離することで分解物を含む共存物質の問題を回避して解析することが可能である．本研究では，泳動緩衝液のpHに伴う電気泳動移動度の変化から分解条件下でヒドロクロロチアジドのpKaを決定したところ，分解生成物の共存下で二段階のpKa1＝8.95±0.04，pKa2＝10.66±0.07が得られた．また，分解生成物である4-アミノ-6-クロロ-m-ベンゼンジスルホンアミドについても電気泳動移動度の変化から二段階のpKaを決定することができ，pKa1＝9.27±0.06，pKa2＝10.79±0.10が得られた．Hydrochlorothiazide, one of the popular diuretics, is degradable in an aqueous solution by hydrolysis, gradually forming 4-amino-6-chloro-m-benzenedisulfonamide. Upon determining the physicochemical constants such as acid dissociation constant (pKa), the coexistence of any degraded species is not desirable. However, equilibrium analysis with the effective electrophoretic mobility measured by capillary zone electrophoresis (CZE) can allow the coexistence of such degraded substances. In this study, acid dissociation constants were determined by CZE with hydrochlorothiazide (HCT) under its degraded conditions. Two steps of the successive acid-dissociation constants have been determined with HCT as pKa1 = 8.95±0.04 and pKa2 = 10.66±0.07; the values agree well with those determined with a freshly prepared HCT solution. Further, two steps of the successive acid-dissociation constants were also determined with the degradant from HCT, 4-amino-6-chloro-m-benzenedisulfonamide, by the CZE analysis utilizing the resolution of the degradant from HCT; pKa1 = 9.27±0.06 and pKa2 = 10.79±0.10 were determined. The potential of the equilibrium analysis by CZE was demonstrated with the degradable HCT

Determination of the Acid-Base Dissociation Constant of Acid-Degradable Hexamethylenetetramine by Capillary Zone Electrophoresis

The acid-base equilibrium of hexamethylenetetramine (hexamine) was analyzed with its effective electrophoretic mobility by capillary zone electrophoresis. Although hexamine is degradable in a weakly acidic aqueous solution, and the degraded products of ammonia and formaldehyde can be formed, the effective electrophoretic mobility of hexamine was measured in the pH range between 2.8 and 6.9. An acid-base dissociation equilibrium of the protonated hexamine was analyzed based on the mobility change, and an acid dissociation constant of pKa = 4.93 ± 0.01 (mean ± standard error, ionic strength: 0.020 mol dm–3) was determined. The monoprotic acid-base equilibrium of hexamine was confirmed through comparisons of its electrophoretic mobility with the N-ethylquinolinium ion and with the monocationic N-ethyl derivative of hexamine, as well as a slope analysis of the dissociation equilibrium

Polyethylene Glycols for the Dispersion Development of Graphene in an Aqueous Surfactant Solution Studied by Affinity Capillary Electrophoresis

Water-soluble nonionic polymers of polyethylene glycol (PEG), poly(vinyl alcohol) (PVA), and polyvinylpyrrolidone (PVP) were examined to develop the dispersion of graphene in an aqueous surfactant solution. Sodium dodecylbenzenesulfonate was used as an anionic surfactant to disperse graphene in an aqueous solution and to give negative charge on it. The dispersion of graphene was monitored through the electropherograms in affinity capillary electrophoresis; a broad peak for the dispersed graphene and shot signals for the aggregated one. When PEG was added in the separation buffer as an affinity reagent, the number of the shot signals in the electropherogram was reduced; PEG can develop the dispersion of graphene in an aqueous surfactant solution. The dispersion was also developed with PVP or PVA. The effective electrophoretic mobility of the dispersed graphene was reduced by using the polymer as an affinity reagent. The result suggested that the anionic surfactant on the graphene surface was competitively substituted with the nonionic polymer. The degree of the decrease in the effective electrophoretic mobility was larger with PEG with a high-molecular mass. The broad peak of the dispersed graphene got narrower by the addition of PEG, and the number of theoretical plates was improved

Mining-Guided Machine Learning Analyses Revealed the Latest Trends in Neuro-Oncology

In conducting medical research, a system which can objectively predict the future trends of the given research field is awaited. This study aims to establish a novel and versatile algorithm that predicts the latest trends in neuro-oncology. Seventy-nine neuro-oncological research fields were selected with computational sorting methods such as text-mining analyses. Thirty journals that represent the recent trends in neuro-oncology were also selected. As a novel concept, the annual impact (AI) of each year was calculated for each journal and field (number of articles published in the journal &#215; impact factor of the journal). The AI index (AII) for the year was defined as the sum of the AIs of the 30 journals. The AII trends of the 79 fields from 2008 to 2017 were subjected to machine learning predicting analyses. The accuracy of the predictions was validated using actual past data. With this algorithm, the latest trends in neuro-oncology were predicted. As a result, the linear prediction model achieved relatively good accuracy. The predicted hottest fields in recent neuro-oncology included some interesting emerging fields such as microenvironment and anti-mitosis. This algorithm may be an effective and versatile tool for prediction of future trends in a particular medical field