871 research outputs found
Bone Regeneration with Wharton's Jelly-Bioceramic-Bioglass Composite
The aim of this development is to optimize a bone substitute (BS) for use in tissue engineering. This is achieved through the combination of three phases in a biocomposite (BCO), in which each is reabsorbed in the site of implantation and replaced by autologous bone (patient´s own). The inorganic phases are composed of irregular particles (150-300 microns) obtained by milling and sieving of a biphasic bioceramic (BC) of hydroxyapatite (HA of bovine origin) with 40% (wt.) β-tricalcium phosphate (β- TCP, obtained by chemical synthesis) and Bioglass type 45S5 (45SiO2 -24,5CaO - 24,5Na2O - 6P2O5, in % wt.). Instead, the organic phase consists of collagen extracted from Wharton´s jelly (part of the human embryonic tissue) from physical and chemical self-developed process. The BC is produced by mixture of HA and β-TCP (Bone Regeneration with Wharton´s Jelly-Bioceramic-Bioglass Composite. Available from: Fil: Fernández, C.A.. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Química; ArgentinaFil: Martínez, C.A.. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Química; Argentina. Universidad Nacional de Cuyo. Facultad de Odontologia; ArgentinaFil: Prado, Miguel Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Comision Nacional de Energia Atomica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Investigación Aplicada. Grupo de Materiales Nucleares; ArgentinaFil: Olmedo, Daniel Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Ozols, Andres. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin
Kahler Anomalies in Supergravity and Flux Vacua
We review the subject of Kahler anomalies in gauged supergravity, emphasizing
that field equations are inconsistent when the Kahler potential is
non-invariant under gauge transformations or when there are elementary
Fayet-Iliopoulos couplings. Flux vacua solutions of string theory with gauged
U(1) shift symmetries appear to avoid this problem. The covariant Kahler
anomalies involve tensors which are composite functions of the scalars as well
as the gauge field strength and space-time curvature tensors. Anomaly
cancellation conditions will be discussed in a sequel to this paper.Comment: 29 pages; v2: revised presentation, section on Fayet-Iliopoulos
couplings cut, effects of gauginos on anomalies included, references adde
Hospital readiness at Yogyakarta and surrounding areas to implement telepsychiatry
Purpose: This study aims to determine hospitals’ readiness before implementing telepsychiatry.Method: This case study analyses the results of interviews from Head of Psychiatry Department or equivalent, information systems administrator and psychiatrist at 3 Mental Hospitals and 1 General Hospital. Interviews and observations were then compared with related theories.Results: RSJS Magelang does not have adequate infrastructure for telepsychiatry implementation. RSUP Sardjito having difficulties in terms of management, infrastructure and the desire to use telepsychiatry. RSJ Grhasia having obstacles in terms of management and fulfillment of infrastructure needs. RSJD Soedjarwadi does not have any obstacles if they start to implement telepsychiatry.Conclusion: RSJD Soedjarwadi is ready to implement telepsychiatry. As for other hospitals need further improvement, mainly in their infrastructur
Anomaly Cancellation in Supergravity with Fayet-Iliopoulos Couplings
We review and clarify the cancellation conditions for gauge anomalies which
occur when N=1, D=4 supergravity is coupled to a Kahler non-linear sigma-model
with gauged isometries and Fayet-Iliopoulos couplings. For a flat sigma-model
target space and vanishing Fayet-Iliopoulos couplings, consistency requires
just the conventional anomaly cancellation conditions. A consistent model with
non-vanishing Fayet-Iliopoulos couplings is unlikely unless the Green-Schwarz
mechanism is used. In this case the U(1) gauge boson becomes massive and the
D-term potential receives corrections. A Green-Schwarz mechanism can remove
both the abelian and certain non-abelian anomalies in models with a gauge
non-invariant Kahler potential.Comment: 27 page
Prevalidation of body sway shooting test without the use of weapons
El principal objetivo de este estudio es realizar un estudio previo a la
validación de un test de medición del equilibrio en tiro olímpico sin el uso de la
pistola. Para ello, se han comparado los resultados del análisis del movimiento del
centro de presiones (CP) de dos pruebas de equilibrio estático: en la primera prueba
se usó una mancuerna para simular la acción de disparo, mientras que en la
segunda se usó la pistola. Se encontró una fuerte correlación entre los dos test en
todas las variables del CP y una correlación lineal inversa entre el peso corporal y los movimientos del CP. No se encontró relación alguna entre los movimientos del
CP y el rendimiento deportivo. El estudio concluye que el test con mancuerna puede
ser válido para la medición del equilibrio específico en tiro olímpico y se recomienda
profundizar en el estudio con una muestra de mayor tamañoThe main objective of the present work is the pre-validation of a test able to provide
reliable body sway measurements in Olympic shooting, without the use of a pistol.
For this reason the results of the analysis of the body sway data of two
static bipodal balance tests have been compared: during the first a dumbbell was
used to simulate shooting, while for the second test a pistol was used. A strong
correlation between the two tests regarding all variables was found. A statistically
significant inverse linear correlation was also found between body weight and the
movements of the COP (centre of pressure). No statistically significant relations
were found between the movements of the COP and performance. The study
concludes that dumbbell tests could be perfectly reliable for measuring specific
body sway on Olympic shooting. Future studies on the validation of the same test
with larger sample size are recommende
Laser sintering of PA12 particles studied by in-situ optical, thermal and X-ray characterization
The microstructure of products manufactured by selective laser sintering (SLS) is known to be highly dependent on various process and material parameters. The latter thus also affect the final part properties. While most work has focused on ex-situ characterization of the printed parts, little is known about the time-dependent microstructure development during sintering. In this work, we present direct observations of the microstructural evolution during laser sintering of polyamide 12 (PA12) particle doublets by in-situ synchrotron wide angle X-ray diffraction (WAXD), using our in-house developed laser sintering setup. Simultaneously, the neck growth between the particles and the temperature are captured via optical and infrared microscopy. We show that isothermal crystallization experiments under quiescent conditions are not sufficient to describe crystallization in a non-isothermal process like SLS. The enhanced crystallization kinetics in small particles suggests that both temperature and flow play a role. This finding was corroborated by the critical Weissenberg numbers estimated from rheological reptation and Rouse time scales. Furthermore, a microstructure survey has been carried out by microtoming thin slices of the sintered doublets. Both optical and atomic force microscopy reveal significant differences in the crystalline structure of the laser-affected zone as compared to the un-sintered region.</p
First Report of Homothallic Isolates of Phytophthora infestans in Commercial Potato Crops (Solanum tuberosum) in the Toluca Valley, Mexico
Phytophthora infestans causes severe symptoms of wilt disease on potato crops (Solanum tuberosum) in the Toluca Valley (Mexico)despite the use of fungicides. P. infestans oospores produced by sexual reproduction can survive in the soil for many years, resisting harsh environments
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