655 research outputs found
A Comparison of Corrosion Behavior of Copper and Its Alloy in Pongamia pinnata Oil at Different Conditions
Vegetable oils are promising substitutes for petrodiesel as they can be produced from numerous oil seed crops that can be cultivated anywhere and have high energy contents, exhibiting clean combustion behavior with zero CO2 emission and negligible SO2 generation. The impact of biofuel on the corrosion of various industrial metals is a challenge for using biofuel as automotive fuel. Fuel comes in contact with a wide variety of metallic materials under different temperatures, velocities, and loads thereby causing corrosion during storage and flow of fuel. Hence, the present investigation compares the corrosion rates of copper and brass in Pongamia pinnata oil (O100), 3% NaCl, and oil blend with NaCl (O99) obtained by static immersion test and using rotating cage. The corrosivity and conductivity of the test media are positively correlated. This study suggested that the corrosivity of copper is higher than brass in Pongamia pinnata oil (PO)
Effect of Flow and Dissolved Oxygen on the Compatibility of Pongamia pinnata
The compatibility of Pongamia pinnata biodiesel (PBD) and its NaCl blends on aluminium, brass, copper, carbon steel, and mild steel has been studied by static mass loss and rotating cage methods. The effects of dissolved oxygen and flow on the metal corrosion in PBD were also observed. This study confirmed that the copper strip test alone is not enough to determine the fuel property since the corrosion of ferrous metal was found to be high in PBD compared to other metals. The least corrosion rate of aluminium was confirmed by surface morphology and elemental analysis
Summary of the Activities of the Working Group I on High Energy and Collider Physics
This is a summary of the projects undertaken by the Working Group I on High
Energy Collider Physics at the Eighth Workshop on High Energy Physics
Phenomenology (WHEPP8) held at the Indian Institute of Technology, Mumbai,
January 5-16, 2004. The topics covered are (i) Higgs searches (ii)
supersymmetry searches (iii) extra dimensions and (iv) linear collider.Comment: summary of Working Group I at the Eighth Workshop on High Energy
Physics Phenomenology (WHEPP8), I.I.T., Mumbai, January 5-16, 200
Clinical significance of Phosphatidyl Inositol Synthase overexpression in oral cancer
<p>Abstract</p> <p>Background</p> <p>We reported increased levels of Phosphatidyl Inositol synthase (PI synthase), (enzyme that catalyses phosphatidyl inositol (PI) synthesis-implicated in intracellular signaling and regulation of cell growth) in smokeless tobacco (ST) exposed oral cell cultures by differential display. This study determined the clinical significance of PI synthase overexpression in oral squamous cell carcinoma (OSCC) and premalignant lesions (leukoplakia), and identified the downstream signaling proteins in PI synthase pathway that are perturbed by smokeless tobacco (ST) exposure.</p> <p>Methods</p> <p>Tissue microarray (TMA) Immunohistochemistry, Western blotting, Confocal laser scan microscopy, RT-PCR were performed to define the expression of PI synthase in clinical samples and in oral cell culture systems.</p> <p>Results</p> <p>Significant increase in PI synthase immunoreactivity was observed in premalignant lesions and OSCCs as compared to oral normal tissues (p = 0.000). Further, PI synthase expression was significantly associated with de-differentiation of OSCCs, (p = 0.005) and tobacco consumption (p = 0.03, OR = 9.0). Exposure of oral cell systems to smokeless tobacco (ST) in vitro confirmed increase in PI synthase, Phosphatidylinositol 3-kinase (PI3K) and cyclin D1 levels.</p> <p>Conclusion</p> <p>Collectively, increased PI synthase expression was found to be an early event in oral cancer and a target for smokeless tobacco.</p
Lattice dynamics study of HgGa2Se4 at high pressures
We report on Raman scattering measurements in mercury digallium selenide (HgGa2Se4) up to 25 GPa. We also performed, for the low-pressure defect-chalcopyrite structure, lattice-dynamics ab initio calculations at high pressures which agree with experiments. Measurements evidence that the semiconductor HgGa2Se4 exhibits a pressure-induced phase transition above 19 GPa to a previously undetected structure. This transition is followed by a transformation to a Raman-inactive phase above 23.4 GPa. On downstroke from 25 GPa until 2.5 GPa, a broad Raman spectrum was observed, which has been attributed to a fourth phase, and whose pressure dependence was followed during a second upstroke. Candidate structures for the three phases detected under compression are proposed. Finally, we also report and discuss the decomposition of the sample by laser heating at pressures close to 19 GPa. As possible products of decomposition, we have identified at least the formation of trigonal selenium nanoclusters and cinnabar-type HgSe.This study was supported by the Spanish government MEC under Grant No. MAT2010-21270-004-01/03/04, by MALTA Consolider Ingenio 2010 project (CSD2007-00045), by Generalitat Valenciana through project GVA-ACOMP-2013-012, and by the Vicerrectorado de Investigacion y Desarrollo of the Universidad Politecnica de Valencia (UPV2011-0966 and UPV2011-0914). E.P.-G., J.L.-S., A.M., and P.R.-H. acknowledge computing time provided by Red Espanola de Super-computacion (RES) and MALTA-Cluster.Vilaplana Cerda, RI.; Gomis Hilario, O.; Manjón Herrera, FJ.; Ortiz, HM.; Pérez González, E.; López Solano, J.; Rodríguez Hernández, P.... (2013). Lattice dynamics study of HgGa2Se4 at high pressures. Journal of Physical Chemistry C. 117(30):15773-15781. https://doi.org/10.1021/jp402493rS15773157811173
Structural and vibrational properties of CdAl2S4 under high pressure: Experimental and theoretical approach
"This document is the Accepted Manuscript version of a Published Work that appeared in final form in
Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher.
To access the final edited and published work see http://dx.doi.org/10.1021/jp5037926.”The behavior of defect chalcopyrite CdAl2S4 at high pressures and ambient temperature has been investigated in a joint experimental and theoretical study. High-pressure X-ray diffraction and Raman scattering measurements were complemented with theoretical ab initio calculations. The equation of state and pressure dependences of the structural parameters of CdAl2S4 were determined and compared to those of other AB(2)X(4) ordered-vacancy compounds. The pressure dependence of the Raman-active mode frequencies is reported, as well as the theoretical phonon dispersion curves and phonon density of states at 1 atm. Our measurements suggest that defect chalcopyrite CdAl2S4 undergoes a phase transition above 15 GPa to a disordered-rocksalt structure, whose equation of state was also obtained up to 25 GPa. In a downstroke from 25 GPa to 1 atm, our measurements indicate that CdAl2S4 does not return to the defect chalcopyrite phase; it partially retains the disordered-rocksalt phase and partially transforms into the spinel structure. The nature of the spinel structure was confirmed by the good agreement of our experimental results with our theoretical calculations. All in all, our experimental and theoretical results provide evidence that the spinel and defect chalcopyrite phases of CdAl2S4 are competitive at 1 atm. This result opens the way to the synthesis of spinel-type CdAl2S4 at near-ambient conditions.Financial support from the Spanish Consolider Ingenio 2010 Program (Project CSD2007-00045) is acknowledged. This work was also supported by Spanish MICCIN under Project MAT2010-21270-C04-03/04 and by Vicerrectorado de Investigacion de la Universitat Politecnica de Valencia under Projects UPV2011-0914 PAID-05-11 and UPV2011-0966 PAID-06-11. Supercomputer time was provided by the Red Espanola de Supercomputacion (RES) and the MALTA cluster. J.A.S. acknowledges the Juan de la Cierva fellowship program for financial support. AM. and P.R.-H. acknowledge S. Munoz Rodriguez for providing a data-parsing application.Sans Tresserras, JÁ.; Santamaría Pérez, D.; Popescu, C.; Gomis, O.; Manjón Herrera, FJ.; Vilaplana Cerda, RI.; Muñoz, A.... (2014). Structural and vibrational properties of CdAl2S4 under high pressure: Experimental and theoretical approach. Journal of Physical Chemistry C. 118(28):15363-15374. https://doi.org/10.1021/jp5037926S15363153741182
Are textbook lungs really normal? A cadaveric study on the anatomical and clinical importance of variations in the major lung fissures, and the incomplete right horizontal fissure.
INTRODUCTION: The lungs have three main fissures: the right oblique fissure (ROF), right horizontal fissure (RHF), and left oblique fissure (LOF). These can be complete, incomplete or absent; quantifying the degree of completeness of these fissures is novel. Standard textbooks often refer to the fissures as complete, but awareness of variation is essential in thoracic surgery. MATERIALS AND METHODS: Fissures in 81 pairs of cadaveric lungs were classified. Oblique fissures were measured from lung hila posteriorly to the lung hila anteriorly; and the RHF measured from the ROF to the anteromedial lung edge. The degree of completeness of fissures was expressed as a percentage of the total projected length were they to be complete. The frequency and location of accessory fissures was noted. RESULTS: LOF were complete in 66/81 (81.5%), incomplete in 13/81 (16.0%) and absent in 2/81 (2.47%); ROF were complete in 52/81 (64.2%), incomplete in 29/81 (35.8%) and never absent; RHF were more variable, complete in 18/81 (22.2%), incomplete in 54/81 (66.7%) and absent in 9/81 (11.1%). LOF and ROF were on average 97.1% and 91.6% complete, respectively, being deficient posteriorly at the lung hila. The RHF on average 69.4% complete, being deficient anteromedially. There were accessory fissures in 10 left and 19 right lungs. CONCLUSIONS: This study provides a projection of the anatomy thoracic surgeons may encounter at operation, in particular the variable RHF. This knowledge is essential for optimal outcomes in both benign and oncological procedures influenced by the fissures
Gremlin 1 identifies a skeletal stem cell with bone, cartilage, and reticular stromal potential
The stem cells that maintain and repair the postnatal skeleton remain undefined. One model suggests that perisinusoidal mesenchymal stem cells (MSCs) give rise to osteoblasts, chondrocytes, marrow stromal cells, and adipocytes, although the existence of these cells has not been proven through fate-mapping experiments. We demonstrate here that expression of the bone morphogenetic protein (BMP) antagonist gremlin 1 defines a population of osteochondroreticular (OCR) stem cells in the bone marrow. OCR stem cells self-renew and generate osteoblasts, chondrocytes, and reticular marrow stromal cells, but not adipocytes. OCR stem cells are concentrated within the metaphysis of long bones not in the perisinusoidal space and are needed for bone development, bone remodeling, and fracture repair. Grem1 expression also identifies intestinal reticular stem cells (iRSCs) that are cells of origin for the periepithelial intestinal mesenchymal sheath. Grem1 expression identifies distinct connective tissue stem cells in both the bone (OCR stem cells) and the intestine (iRSCs)
Structural and vibrational study of pseudocubic CdIn2Se4 under compression
This document is the Accepted Manuscript version of a Published Work that appeared in final form in
Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher.
To access the final edited and published work see http://dx.doi.org/10.1021/jp5077565We report a comprehensive experimental and theoretical study of the structural and vibrational properties of a-CdIn2Se4 under compression. Angle-dispersive synchrotron X-ray diffraction and Raman spectroscopy evidence that this ordered-vacancy compound with pseudocubic structure undergoes a phase transition (7 GPa) toward a disordered rocksalt structure as observed in many other ordered-vacancy compounds. The equation of state and the pressure dependence of the Raman-active modes of this semiconductor have been determined and compared both to ab initio total energy and lattice dynamics calculations and to related compounds. Interestingly, on decreasing pressure, at similar to 2 GPa, CdIn2Se4 transforms into a spinel structure which, according to calculations, is energetically competitive with the initial pseudocubic phase. The phase behavior of this compound under compression and the structural and compressibility trends in AB(2)Se(4) selenides are discussed.This study was supported by the Spanish government MEC under Grant Nos: MAT2013-46649-C4-3-P, MAT2013-46649-C4-2-P, MAT2010-21270-C04-03/04, and CTQ2009-14596-C02-01, by MALTA Consolider Ingenio 2010 Project (CSD2007-00045) and by Generalitat Valenciana (GVA-ACOMP-2013-1012). A.M. and P.R-H. acknowledge computing time provided by Red Espanola de Supercomputacion (RES) and MALTA-Cluster, and also to S. Munoz-Rodriguez for providing a data-parsing application. J.A.S. acknowledges Juan de la Cierva fellowship program for financial support.Santamaría Pérez, D.; Gomis, O.; Pereira, ALJ.; Vilaplana Cerda, RI.; Popescu, C.; Sans Tresserras, JÁ.; Manjón Herrera, FJ.... (2014). Structural and vibrational study of pseudocubic CdIn2Se4 under compression. Journal of Physical Chemistry C. 118(46):26987-26999. https://doi.org/10.1021/jp5077565S26987269991184
IL1B Induced Smad 7 Negatively Regulates Gastrin Expression
BACKGROUND: Helicobacter pylori elicited IL1B is one of the various modulators responsible for perturbation of acid secretion in gut. We have earlier reported that IL1B activated NFkB downregulates gastrin, a major modulator of acid secretion. However, we hypothesized that regulation of gastrin by IL1B would depend on the cell's ability to integrate inputs from multiple signaling pathways to generate appropriate biological response. PRINCIPAL FINDING: In this study, we report that IL1B induces Smad 7 expression by about 4.5 fold in gastric carcinoma cell line, AGS. Smad 7 resulted in transcriptional repression of gastrin promoter by about 6.5 fold when co-transfected with Smad 7 expression vector and gastrin-promoter luciferase in AGS cells. IL1B inhibited phosphorylation of Smad 3 and subsequently interfered with nuclear translocation of the positive Smad complex, thus occluding it off the gastrin promoter. IL1B promoter polymorphisms (-511T/-31C IL1B) are known to be associated with H. pylori associated gastro-duodenal ulcer. We observed that IL1B expressed from -31T promoter driven IL1B cDNA elicited 3.5 fold more Smad 7 than that expressed from the IL1B-31C variant in AGS cells. This differential activation of Smad 7 by IL1B promoter variants translated into differential downregulation of gastrin expression. We further analyzed Smad 7, NFkB, IL1B and gastrin expression in antral gut biopsy samples of patients with H. pylori associated duodenal ulcer and normal individuals. We observed that individuals with duodenal ulcer had significantly lower levels of IL1B, Smad 7, NFkB and corresponding higher level of gastrin expression. CONCLUSION: Pro-inflammatory cytokine IL1B repress gastrin expression by activating Smad 7 and subsequent inhibition of nuclear localization of Smad 3/4 complex. Polymorphic promoter variants of IL1B gene can modulate the IL1B expression which resulted in differential activation Smad 7 and consequent repression of gastrin expression, respectively. Analysis of H. pylori infected duodenal ulcer patient's gut biopsy samples also supported this observation
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