The corrosion inhibition of stainless steel by ferrocene-polyoxometalate hybrid molecular materials - experimental and first principles studies.

The hybrid molecular materials [Fe(C5H5)2]3[PW12O40]·(H2O)4 and [Fe(C5H5)2]3[PMo12O40]·(H2O)6, denoted respectively as FcPW and FcPMo, are synthesized via a co-precipitation method under acidic conditions (pH: ∼2-3). The molecular properties of these compounds are investigated via various analytical methods. UV-vis diffuse reflectance and photoluminescence studies confirm that these compounds are charge-transfer salts. Stainless steel plates (SS, 316 grade) coated with these hybrid compounds and dipped in 0.5 M H2SO4 and Ringer's solutions show significantly inhibited corrosion. The corrosion inhibition properties of these materials are studied via weight loss, electrochemical impedance spectroscopy, and potentiodynamic polarization studies. The reproducibility of the corrosion inhibition results is ensured via repeat measurements, and error values are reported. The surfaces of the corroded steel plates are examined via scanning electron and atomic force microscopy techniques. It is found that the corrosion is of uniform type. The Tafel extrapolation method shows that the inhibition efficiency is 74% for SS@FcPMo and 65% for SS@FcPW. The corrosion inhibition mechanism is explained based on the redox nature of the hybrid materials. The experimental results are corroborated through computational studies carried out using a first principles approach with the optimized geometries and frontier molecular orbitals of the hybrid molecular materials.

Cheiloscopy and dermatoglyphics as screening tools for type 2 diabetes mellitus.

AIM: The aim of this study is to evaluate the efficacy of cheiloscopy (the study of lip prints) and dermatoglyphics (the study of fingerprints) in screening diabetic patients. MATERIALS AND METHODS: The study sample comprised 100 individuals in the age group of 17-60 years, of which fifty were diabetics and fifty controls who reported to the Department of Oral Medicine, Thai Moogambigai Dental College and Hospital. Lip prints were collected and categorized based on the Suzuki and Tsuchihashi system. Fingerprint patterns were obtained and classified according to the Henry's system of classification. RESULTS: Type II and IV lip print patterns were predominant in diabetic patients and Type I lip print patterns in controls. The difference was statistically significant. There was no significant difference in fingerprint patterns between the study groups. Gender-wise analysis for lip print and fingerprint patterns did not yield significant results. CONCLUSION: Cheiloscopy is a potential screening tool for type 2 diabetes mellitus. Dermatoglyphics cannot be used as a screening tool in type 2 diabetes mellitus.