Development and Characterization of Mg-SiC Nanocomposite Powders Synthesized by Mechanical Milling

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Magnesium powder in micron scale and various volume fractions of SiC particles with an average diameter of 50 nm were co-milled by a high energy planetary ball mill for up to 25 h to produce Mg-SiC nanocomposite powders. The milled Mg-SiC nanocomposite powders were characterized by scanning electron microscopy (SEM) and laser particle size analysis (PSA) to study morphological evolutions. Furthermore, XRD, TEM, EDAX and SEM analyses were performed to investigate the microstructure of the magnesium matrix and distribution of SiC-reinforcement. It was shown that with addition of and increase in SiC nanoparticle content, finer particles with narrower size distribution are obtained after mechanical milling. The morphology of these particles also became more equiaxed at shorter milling times. The microstructural observation revealed that the milling process ensured uniform distribution of SiC nanoparticles in the magnesium matrix even with a high volume fraction, up to 10 vol%

A propos de l'utilisation du COFDM pour les réseaux locaux sans fil haut débit

- Cet article présente les avantages techniques apportés par le COFDM (Coded Orthogonal Frequency Division Multiplex) aux réseaux locaux sans fil haut débit, dans le cadre des études du système Hiperlan2 par le projet ETSI/BRAN (Broadband Radio Access Network). Le choix des paramètres clé d'un système COFDM dédié à de tels réseaux est analysé. La comparaison de deux systèmes de modulation différentielle est plus particulièrement approfondie

The CADM1 tumor suppressor gene is a major candidate gene in MDS with deletion of the long arm of chromosome 11.

Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis leading to peripheral cytopenias and in a substantial proportion of cases to acute myeloid leukemia. The deletion of the long arm of chromosome 11, del(11q), is a rare but recurrent clonal event in MDS. Here, we detail the largest series of 113 cases of MDS and myelodysplastic syndromes/myeloproliferative neoplasms (MDS/MPN) harboring a del(11q) analyzed at clinical, cytological, cytogenetic, and molecular levels. Female predominance, a survival prognosis similar to other MDS, a low monocyte count, and dysmegakaryopoiesis were the specific clinical and cytological features of del(11q) MDS. In most cases, del(11q) was isolated, primary and interstitial encompassing the 11q22-23 region containing ATM, KMT2A, and CBL genes. The common deleted region at 11q23.2 is centered on an intergenic region between CADM1 (also known as Tumor Suppressor in Lung Cancer 1) and NXPE2. CADM1 was expressed in all myeloid cells analyzed in contrast to NXPE2. At the functional level, the deletion of Cadm1 in murine Lineage-Sca1+Kit+ cells modifies the lymphoid-to-myeloid ratio in bone marrow, although not altering their multilineage hematopoietic reconstitution potential after syngenic transplantation. Together with the frequent simultaneous deletions of KMT2A, ATM, and CBL and mutations of ASXL1, SF3B1, and CBL, we show that CADM1 may be important in the physiopathology of the del(11q) MDS, extending its role as tumor-suppressor gene from solid tumors to hematopoietic malignancies

Could increased axial wall stress be responsible for the development of atheroma in the proximal segment of myocardial bridges?

<p>Abstract</p> <p>Background</p> <p>A recent model describing the mechanical interaction between a stenosis and the vessel wall has shown that axial wall stress can considerably increase in the region immediately proximal to the stenosis during the (forward) flow phases, so that abnormal biological processes and wall damages are likely to be induced in that region. Our objective was to examine what this model predicts when applied to myocardial bridges.</p> <p>Method</p> <p>The model was adapted to the hemodynamic particularities of myocardial bridges and used to estimate by means of a numerical example the cyclic increase in axial wall stress in the vessel segment proximal to the bridge. The consistence of the results with reported observations on the presence of atheroma in the proximal, tunneled, and distal vessel segments of bridged coronary arteries was also examined.</p> <p>Results</p> <p>1) Axial wall stress can markedly increase in the entrance region of the bridge during the cardiac cycle. 2) This is consistent with reported observations showing that this region is particularly prone to atherosclerosis.</p> <p>Conclusion</p> <p>The proposed mechanical explanation of atherosclerosis in bridged coronary arteries indicates that angioplasty and other similar interventions will not stop the development of atherosclerosis at the bridge entrance and in the proximal epicardial segment if the decrease of the lumen of the tunneled segment during systole is not considerably reduced.</p

Bericht \ufcber die 1914 ausgef\ufchrte zoologsiche Forschungsreise im nordalbanisch-montenegrinischen Grenzgebiet (Ergebnisse einer von der Kaiserl. Akademie der Wissenschaften in Wien veranla ften naturwissenschaftlichen Forschungsreise in Nordalbanien)

Volume: 123Start Page: 1131End Page: 114

Gnomonica Fundamentalis & Mechanica : worinnen gewiesen wird, wie man sowol gründlich, als auf mechanische Art, allerhand Sonnen-Uhren regulaire, irregulaire, mit Minuten und himmlischen Zeichen, auf allerhand Flächen ... verfertigen solle. Wozu noch eine neue Invention einer Universal-Sonnen-Uhr kommt, welche ohne Magnet-Nadel zu stellen, selbst die wahre Mitternachts-Linie, und Abweichung aller Wände von denen Haupt-Plagis Mundi, wie auch Elevationem Poli bey Tage anzeiget, und zu Solvirung noch anderer Problematum dienet

entworfen und mitgetheilet von Johann Friedrich Penther, Gräflich-Stolbergischen Cammer-RathGnomonica Fvndamentalis Et Mechanica PentheriVorlageform des Erscheinungsvermerks: Augspurg, Jn Verlag bey Johann Georg Hertel, Kunsthändler. Gedruckt bey Johann Jacob Lotter 1760

Gnomonica Fundamentalis Et Mechanica : Worinnen gewiesen wird, wie man so wohl gründlich als auf Mechanischer Art Allerhand Sonnen-Uhren, Regulaire, Irregulaire mit Minuten und Himmlischen Zeichen auf allerhand Flächen, sie mögen Gleich oder Höckericht, Beweglich oder Unbeweglich seyn, verfertigen solle ; Worzu noch eine neue Invention einer Universal-Sonnen-Uhr kommt, welche ohne Magnet-Nadel zu stellen, selbst die wahre Mitternachts Linie, und Abweichung aller Wände von denen Haupt-Plagis Mundi, wie auch Elevationem Poli bey Tage anzeiget, und zu Solvirung noch anderer Problematum dienet

entworffen und mitgetheilet Von Joh. Friedr. Penther, Gräfflich Stolbergischen Cammer-RathVorlageform des Erscheinungsvermerks: Augspurg Verlegt von Jeremias Wolffs, Kunsthändlers Seel. Erben. Gedruckt, bey Matthæo Schoeneg. 1733

Bericht \ufcber die 1916 im Auftrage und auf Kosten der Kaiserl. Akademie der Wissenschaften in Wien ausgef\ufchrte zoologische Forschungsreise in Serbien und Neumontenegro

Volume: 125Start Page: 579End Page: 59