Papers by John Kurt Sanchez
Circulation, Nov 22, 2011
Background: Coronary artery distensibility index (CDI) is an endothelial-dependent process, assoc... more Background: Coronary artery distensibility index (CDI) is an endothelial-dependent process, associated with vulnerable-plaque (VP) composition, and development of coronary artery disease (CAD). The effects of statin-therapy on CDI and VP composition are not well studied. This study evaluates the response to statin therapy through CDI, VP and clinical outcome. Methods: Two hundred and forty eight subjects (aged 65±8 years, 46% women, and 100% statin-therapy) underwent computed tomography angiography (CTA) and were prospectively followed. CDI in left anterior descending artery (LAD) was defined as: [(Early diastole - mid diastole lumen cross section area (CSA))/ (lumen CSA in mid diastole x central pulse pressure) x 1000]. Vulnerable-plaque composite-score (VPS) was measured using semi-quantified plaque volume (none, localized, intermediate, or diffuse) and severity of diseased coronaries (normal, mild, moderate, or severe) in non-calcified and mixed plaques based on American Heart Association 15-segment model. Major adverse cardiac event (MACE) was defined as myocardial infarction or cardiovascular-death. Impaired CDI (0) distinguished non-responders from responders to statin therapy. Results: During a median of 36-month follow-up, the event Rate was 10.1% (12.1% in men and 6.25% in women). After adjustment for risk factors, the risk of MACE was 628% and 226% higher in impaired CDI and VPS as compared to normal cohort, which were different between genders (p Conclusions: Statin therapy is associated with sex-specific cardio-protective effects by improving CDI and decreasing VPS, and reduces MACE independent of conventional risk factors.
Circulation, Nov 22, 2011
Journal of the American College of Cardiology, 2012
Background: Increased pulse wave velocity (PWV), marker of vascular function, is associated with ... more Background: Increased pulse wave velocity (PWV), marker of vascular function, is associated with cardiovascular risk factors. This study investigates the long-term clinical outcome of subjects with and without increased PWV. Methods: Two hundred and forty eight subjects (aged 65±8 years, 46% women, and 100% statin therapy) underwent computed tomography angiography (CTA) and were prospectively followed. PWV measured in CTA timing bolus phase was calculated as: the ratio of distance over time difference between contrast enhancements of Ascending and Descending Aorta (m/sec). Coronary artery disease was defined as luminal stenosis 1-49% (non-obstructive) and 50%+ (obstructive). Major adverse cardiac event (MACE) was defined as myocardial infarction or cardiovascular death. Results: PWV increased proportionally form subjects with normal coronaries (8.1±0.88) to diseased coronaries (10.1±0.89) (P=0.001). During a median follow up of 36-month, the MACE rate was 10.1%. The adjusted relative risk of MACE was 4.95 (95%CI 1.04-9.16), and 8.02 (95%CI 1.73-17.09) in intermediate and highest tertiles of PWV as compared to lowest tertile of PWV, respectively. The event free survival rate decreased significantly with increase in PWV across each CAD category from 100% in normal coronaries with lowest PWV tertile to 75% in obstructive CAD with highest PWV tertile. (Figure) Conclusion: Increased PWV is independently associated with coronary atherosclerosis and predicts MACE.
Communication Quarterly, 2000
Political rhetoric in a democracy is, in at least some sense, educative and constitutive even as ... more Political rhetoric in a democracy is, in at least some sense, educative and constitutive even as it is instrumentally persuasive. For members of ethnic, racial, or cultural groups that lie outside of the dominant culture, the educative processes that underlie policy advocacy require attention to specific cultures, traditions, historical experiences, and group interests. Thus, even though all out-groups share many common challenges, they all face unique situations as well. This essay explores these rhetorical challenges and some of the strategies designed to meet them through an examination of the political rhetoric of American Indian activists from the 1972 Trail of Broken Treaties through the 1973 siege at Wounded Knee, South Dakota. Particular attention is paid to the question of audience.
MRS Online Proceedings Library, 1992
Íconos - Revista de Ciencias Sociales, 2013
Íconos, Revista de Ciencias Sociales es una publicación de Flacso-Ecuador. Fue fundada en 1997 co... more Íconos, Revista de Ciencias Sociales es una publicación de Flacso-Ecuador. Fue fundada en 1997 con el fin de estimular una reflexión crítica desde las ciencias sociales sobre temas de debate social, político, cultural y económico del país, la región andina y el mundo en general. La revista está dirigida a la comunidad científica y a quienes se interesen por conocer, ampliar y profundizar, desde perspectivas académicas, estos temas. Íconos se publica cuatrimestralmente en los meses de enero, mayo y septiembre. Para la selección de artículos se utiliza un arbitraje bajo el sistema de doble ciego ipeer review). Indexacián Íconos está incluida en los siguientes índices científicos: Sociological Abstracrs, Ulrich's, Hispanic American Periodical Index (HAPI), Thornpson Gale (Informe Académico), EBSCO-Fuente Académica, Latindex-Catálogo, REDALyC (Red de Revistas Científicas de América Latina y el Caribe) y CLASE (Citas Latinoamericanas en Ciencias Sociales). Iconos On Line Los contenidos de Íconos son accesibles on fine en texto completo a través de los portales de REDALyC (www.redalyc.org), CLACSO (www.clacso.org.ar/bibliotecalrevistas). Tecnociencia (Consejo Superior de Investigación Científica de España), DOAJ (www.doaj.org), FLACSO-Ecuador (www.flacso.org.ec/htmlliconos.html). Los artículos que se publican en la revista son de responsabilidad exclusiva de sus autores; no reflejan necesariamente el pensamiento de Íconos. Se autoriza la reproducción total o parcial de los contenidos siempre que se cite expresamente como fuente a Íconos,
Physical Review B, 2000
Evolution of surface structure during the growth of sputter-deposited polycrystalline Al films is... more Evolution of surface structure during the growth of sputter-deposited polycrystalline Al films is studied by means of atomic force microscopy and dynamic scaling by power spectral density and image variography analyses. We incorporate the effects of grain growth based on quantitative measurements of grain size, morphology, and texture orientation through transmission electron microscopy and x-ray diffraction pole figure texture measurements. Temporal regimes of early surface smoothing followed by roughening are explained by the effects of grain-boundary grooves and grain growth during deposition. Three distinct surface morphologies described as flat grains, hillocks, and ridges develop during film growth. The ridges are periodic structures with constant spacing during growth that form along ͗110͘ directions on vicinal ͑111͒-oriented grains and are due to spontaneous development and growth of steps along ͗110͘ directions induced by the Schwoebel-barrier mechanism. The spacing of ridge structures and the well-characterized median grain size correspond to characteristic dimensions that define transitions between regimes of combinations of physical processes responsible for surface evolution. We found a surface-diffusion-dominated anomalous scaling growth mode (␣Ͼ1) at short length scales and a nonlinear KPZ type mode (␣Ϸ0.35) at longer length scales.
Materials Science Forum, 1992
or process disdosed, or represents that its use would not infringe privately owned rights. Refere... more or process disdosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or The Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or The Regents of the University of California and shall not be used for advertising or product endorsement purposes.
Journal of Electronic Materials, 2002
Journal of Applied Physics, 1999
The effects of applied strain on the resistivity of Al thin film metallization interconnects have... more The effects of applied strain on the resistivity of Al thin film metallization interconnects have been measured with a novel methodology that uses thermal expansion mismatch to produce the strain. The interconnect volumetric strain is induced by thermal cycling of passivated and unpassivated interconnects between ≈70 and 373 K. The coefficient of piezoresistivity, defined as dρ/dεv, where ρ=resistivity and εv=volumetric strain, is determined by properly accounting for the degree of interconnect constraint and thermal expansion mismatch strain induced during temperature changes. The volumetric strains are calculated for unpassivated and passivated lines of varying thickness and width. A model which incorporates the geometrical and piezoresistance effects on the measured interconnect resistance during temperature changes is described. The coefficient of piezoresistivity is calculated by a fitting procedure which provides an accurate and consistent fit for both unpassivated and passiva...
Journal of Applied Physics, 1999
Quantitative roughness and microstructural analysis of as-deposited Al films, 0.1–1.0 μm thick, w... more Quantitative roughness and microstructural analysis of as-deposited Al films, 0.1–1.0 μm thick, were performed by atomic force microscopy (AFM), one-dimensional power spectral density analysis (1DPSD), transmission electron microscopy, and x-ray pole figure methods. The variation of grain size (d) with thickness (h) in the columnar grained film was d∝h0.9. The initial crystallographic texture was nearly random, with a strong Al (111) fiber texture evolving by ≈0.2 μm in deposited thickness. AFM imaging revealed a surface structure with hillocks, grains, and grain boundary grooves, and periodic within-grain ridges extending over entire grains. The root-mean-square surface height variation (RRMS) initially decreased during deposition but increased as RRMS∝h0.55 from 0.3 to 1.0 μm thickness. The 1DPSD analysis revealed three spatially resolved regimes of roughness evolution; a frequency independent regime at low frequency attributed to hillock growth, an intermediate frequency self-sim...
Journal of Applied Physics, 1997
The role of crystallographic texture in electromigration resistance of interconnect lines is well... more The role of crystallographic texture in electromigration resistance of interconnect lines is well documented. The presence of a strong (111) fiber texture results in a more reliable interconnect structure. It is also generally accepted that grain-boundary diffusion is the primary mechanism by which electromigration failures occur. It has been difficult to this point, however, to obtain statistically reliable information of grain-boundary structure in these materials as transmission electron microscopy investigations are limited by tedious specimen preparation and small, nonrepresentative, imaging regions. The present work focuses upon characterization of texture and grain-boundary structure of interconnect lines using orientation imaging microscopy, and particularly, upon the linewidth dependence of these measures. Conventionally processed Al–1%Cu lines were investigated to determine the affects of a postpatterning anneal on boundary structure as a function of linewidth. It was obse...
Journal of Applied Physics, 1994
The behavior of electromigration-induced voids in narrow, unpassivated aluminum interconnects is ... more The behavior of electromigration-induced voids in narrow, unpassivated aluminum interconnects is examined, using scanning electron microscopy. Some electromigration tests were interrupted several times in order to observe void nucleation, void growth, and finally the failure of the conductor line. It is found that voids which opened the line have a specific asymmetric shape with respect to the electron flow direction. Besides void nucleation and void growth, void shape changes can consume a major part of the lifetime of the conductor line. A first attempt to model these processes on the basis of diffusion along the void surface shows that voids with a noncircular initial shape tend to produce the fatal asymmetry due to electron wind effects, with the anisotropy of surface energy possibly playing only a minor role.
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Papers by John Kurt Sanchez