There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

비만아 부모의 돌봄 경험: q 방법론

Tables of integrals

Deep eutectic solvents (DESs) are an emerging class of mixtures characterized by significant depressions in melting points compared to those of the neat constituent components. These materials are promising for applications as inexpensive "designer" solvents exhibiting a host of tunable physicochemical properties. A detailed review of the current literature reveals the lack of predictive understanding of the microscopic mechanisms that govern the structure-property relationships in this class of solvents. Complex hydrogen bonding is postulated as the root cause of their melting point depressions and physicochemical properties; to understand these hydrogen bonded networks, it is imperative to study these systems as dynamic entities using both simulations and experiments. This review emphasizes recent research efforts in order to elucidate the next steps needed to develop a fundamental framework needed for a deeper understanding of DESs. It covers recent developments in DES research, frames outstanding scientific questions, and identifies promising research thrusts aligned with the advancement of the field toward predictive models and fundamental understanding of these solvents.

Deep Eutectic Solvents: A Review of Fundamentals and Applications.

The dc and ac conductivity of polyaniline–polyvinyl alcohol blends

Electrical resistance and magnetoresistance of the HCl doped polyaniline (PANI) in aqueous ethanol medium and polyaniline–methyl cellulose dispersion (PANI–MC) has been investigated at low temperature down to 1.8 K and in magnetic field up to 8 T. The weaker temperature dependence of resistivity characterized by the resistivity ratio ρr=ρ(1.8 K)/ρ(300 K) indicates that a better homogeneity and less disorder can be obtained by protonation with HCl in ethanol media. The temperature dependence of resistivity for both PANI and PANI–MC has been analyzed by three-dimensional variable range hopping (VRH) type of conduction. The samples with the resistivity ratio lying in the range of 102⩽ρr⩽103 exhibit a crossover from Mott to Efros–Shklovskii VRH conduction below 10 K. A large positive magnetoresistance at low temperature has been obtained.

Transport properties of HCl doped polyaniline and polyaniline–methyl cellulose dispersion

Magnesium substitution in carbonated hydroxyapatite: Structural and microstructural characterization by Rietveld's refinement

Crossover from Mott to Efros-Shklovskii variable-range-hopping conductivity in conducting polyaniline

Background: Long-term therapy with metformin was shown to decrease the Vitamin B 12 level and manifested as peripheral neuropathy. Aim: The aim of this study is to define the prevalence of Vitamin B 12 deficiency in early Type 2 diabetic patients (duration ≤5 years or drug treatment ≤3 years) and the relationship among metformin exposure and levels of cobalamin (Cbl), folic acid, and homocysteine (Hcy) with severity of peripheral neuropathy. Methodology: This is a cross-sectional study involving randomly selected ninety patients (male 56, female 34) between age groups of 35 and 70 years, comparing those who had received >6 months of metformin (Group A) ( n = 35) with those without metformin (Group B) ( n = 35) and patients taking metformin with other oral hypoglycemic agent (Group C) ( n = 20). Comparisons were made clinically, biochemically (serum Cbl, fasting Hcy, and folic acid), and with electrophysiological measures (nerve conduction studies of all four limbs). Comorbidities contributing to neuropathy were excluded from the study. Results: Group A patients (54.28%) were prone to develop peripheral neuropathy comparing Group B (28.57%) and Group C (35%). There was significantly low plasma level of Cbl in Group A (mean 306.314 pg/ml) than in Group B (mean 627.543 pg/ml) and Group C (mean 419.920 pg/ml). There was insignificant low-level plasma folic acid in Group A (16.47 ng/ml) than in Group B (16.81 ng/ml) and Group C (22.50 ng/ml). There was significantly high level of Hcy in Group A (mean 17.35 µmol/L) and Group C (mean 16.99 µmol/L) than in Group B (mean 13.22 µmol/L). Metformin users even for 2 years showed evidence of neuropathy on nerve conduction velocity though their body mass index and postprandial blood sugar were maintained. There was significant difference in between groups regarding plasma Cbl, folic acid, and Hcy level as significance level F [2, 87] = 28.1, P = 0.000), ( F [2, 87] = 7.43, P = 0.001), ( F [2, 87] = 9.76, P = 0.000). Post hoc study shows significant ( P Discussion: Even short-term treatment with metformin causes a decrease in serum Cbl folic acid and increase in Hcy, which leads to peripheral neuropathy in Type 2 diabetes patients. A multicenter study with heterogeneous population would have increased the power of the study. We suggest prophylactic Vitamin B 12 and folic acid supplementation or periodical assay in metformin user.

Manas Ghosh

Papers

The dc and ac conductivity of polyaniline–polyvinyl alcohol blends

Transport properties of HCl doped polyaniline and polyaniline–methyl cellulose dispersion

Magnesium substitution in carbonated hydroxyapatite: Structural and microstructural characterization by Rietveld's refinement

Crossover from Mott to Efros-Shklovskii variable-range-hopping conductivity in conducting polyaniline

Study of Vitamin B 12 deficiency and peripheral neuropathy in metformin-treated early Type 2 diabetes mellitus