A Model for Thermal Growth of Ultrathin Silicon Dioxide in O2 Ambient: A Rate Equation Approach

A new thermal oxidation model based on a rate equation approach with concentration dependent diffusion coefficient is proposed for ultrathin SiO2 for thicknesses of the order of 100 Å. The oxidation reaction of silicon is assumed to be dependent on the concentrations of unreacted silicon and oxygen. The results of oxide thickness versus oxidation time for various growth conditions and activation energies for diffusion coefficients are in agreement with various experimental data for O2 ambient

Retroperitoneal inflammatory myofibroblastic tumor

BACKGROUND: Inflammatory myofibroblastic tumor (IMT) is a neoplasm of unknown etiology occurring at various sites. By definition, it is composed of spindle cells (myofibroblasts) with variable inflammatory component, hence the name is IMT. CASE PRESENTATION: The present case is of a 46 years old woman presented with a history of flank pain, abdominal mass and intermittent hematuria for last 6 months. The initial diagnosis was kept as renal cell carcinoma. Finally, it turned out to be a case of retroperitoneal IMT. The patient was managed by complete surgical resection of the tumor. CONCLUSION: IMT is a rare neoplasm of uncertain biological potential. Complete surgical resection remains the mainstay of the treatment

Structure–conductivity correlation in ferric chloride-doped poly(3-hexylthiophene)

Poly(3-hexylthiophene) (P3HT) matrix has been chemically doped (redox doping) by ferric chloride (FeCl3) with different molar concentrations to get P3HT–FeCl3 charge-transfer complexes. The effect of redox doping on photo-physical, structural, and morphological properties and dc electrical conductivity of P3HT matrices has been examined. The dc conductivity has been measured on films of pristine P3HT and P3HT–FeCl3 charge-transfer complexes in the temperature range 6–300 K. Analysis of dc conductivity data reveals that in the temperature range 40–300 K, the dc conductivity is predominantly governed by Mott's 3-dimensional variable range hopping (3D-VRH); however, below 40 K tunnelling seems to dominate. A slight deviation from 3D-VRH to 1D-VRH is observed with an increase in doping level or precisely with an increase in the extent of P3HT–FeCl3 charge-transfer complexes. We attribute this deviation to the induced expansion in crystallographic lattices as revealed by x-ray diffraction data and formation of discrete conducting domains as observed by atomic force microscope imaging

Effect of Fe on the Martensitic Transition, Magnetic and Magnetocaloric Properties in Ni-Mn-In Melt-spun Ribbons

The effect of Fe on the martensitic transitions, magnetic and inverse magnetocaloric effect in Ni47Mn40-xFexIn13 ribbons (x = 1, 2, 3 and 5) has been investigated. All the ribbon compositions under study have shown the presence of austenite phase at room temperature. The variation of martensitic transition with the increase in Fe-content is non-monotonic. The thermal hysteresis of the martensitic transition increased with the increase in Fe-content. The martensitic transitions shifted to lower temperatures in the presence of high magnetic fields. A maximum magnetic entropy change (∆SM) of 50 Jkg-1K-1 has been achieved in the Ni47Mn38Fe2In13 (x = 1) ribbon at 282 K for an applied field of 5 T

Carbamoylphosphonates inhibit autotaxin and metastasis formation in vivo

Autotaxin is an extracellular, two zinc-centered enzyme that hydrolyzes lysophosphatidyl choline to lysophosphatidic acid, involved in various cancerous processes, e.g. migration, proliferation and tumor progression. We examined the autotaxin inhibitory properties of extended structure carbamoylphosphonates (CPOs) PhOC(6)H(4)SO(2)NH(CH(2))nNHCOPO(3)H(2), with increasing lengths of methylene chains, (CH(2))(n), n = 4-8. Carbamoylphosphonates having n = 6, 7, 8 inhibited autotaxin in vitro with IC(50) ≈ 1.5 µM. Using an imaging probe we demonstrated that compound n = 6 inhibits recombinant autotaxin activity in vitro and in vivo, following oral CPO administration. Additionally, daily oral administration of compound n = 7 inhibited over 90% of lung metastases in a murine melanoma metastasis model. Both the carbamoylphosphonates and the enzymes reside and interact in the extracellular space expecting minimal toxic side effects, and presenting a novel approach for inhibiting tumor proliferation and metastasis dissemination

Enantioselective method development and validation of proline by using high performance liquid chromatography

Chirality is a major concern in the modern pharmaceutical industry. The separation of chiral compounds has been of great interest because the majority of bioorganic and synthetic molecules are chiral. Aim of the present investigation was to develop a stereo specific, simple and precise normal phase high performance liquid chromatography (NP - HPLC) method for the separation and enantiopurity of Dextro (D) and Levo (L) enantiomers of proline (PRO) by using Lux 5m Amylose 1 LC column (250.6mm) by using n- Hexane: Iso propyl alcohol (IPA)as mobile phase in the ratios of 90:10 v/v at flow rate of 1.2 ml/ min. D and L forms of PRO was detected at 210nm with retention time of 8.1min and 9 min respectively with correlation coefficient (R 2 ) of 0.999.The method was validated with reference to International conference of harmonization (ICH) in terms of linearity, accuracy, precision (Inter - day and intra - day precision), limit of detection (LOD), limit of quantification (LOQ), stability of test solutions, specificity, system suitability, robustness and ruggedness