2,216 research outputs found
Strain balanced quantum posts
Quantum posts are assembled by epitaxial growth of closely spaced quantum dot
layers, modulating the composition of a semiconductor alloy, typically InGaAs.
In contrast with most self-assembled nanostructures, the height of quantum
posts can be controlled with nanometer precision, up to a maximum value limited
by the accumulated stress due to the lattice mismatch. Here we present a strain
compensation technique based on the controlled incorporation of phosphorous,
which substantially increases the maximum attainable quantum post height. The
luminescence from the resulting nanostructures presents giant linear
polarization anisotropy.Comment: Submitted to Applied Physics Letters (7th March 2011). 4 pages, 4
figure
Pseudoartrosis de escafoides carpiano tratadas mediante la técnica de Matti-Russe: estudio retrospectivo de 36 casos
Presentamos un estudio retrospectivo de una serie de 36 pacientes con pseudoartrosis
de escafoides operados mediante la técnica de Matti-Russe entre 1985 y 1991. Utilizamos
injerto córtico esponjoso obtenido del radio (50%), cresta ilíaca (42%) y cúbito (8%) sin diferencias
en la incorporación. La tasa de curación fue mayor en las pseudoartrosis medias y distales
(80%) que en las de localización proximal (54%). El 80% de los fracasos de curación en la localización
media y distal eran pseudoartrosis de más de 30 meses de evolución. Los cambios degenerativos
en el carpo de las pseudoartrosis no curadas fueron significativamente mayores
(p< 0,001) que en las que se obtuvo la consolidación. La localización y la antiguedad de la pseudoartrosis
parecen ser dos importantes factores pronósticos. La técnica de Matti-Russe presenta limitaciones
en la pseudoartrosis de localización proximal y en los carpos muy degenerados.We reported a retrospective study of 36 patients with a pseudoarthrosis of the
carpal scaphoid bone treated by the Matti-Russe operation from 1985 to 1991. We used radial
(50%), iliac (42%) or ulnar (8%) autogenous grafts without any difference in the rate of incorporation.
The rate of healing of the pseudoarthrosis was higher in mid and distal location
(80%) than in proximal location (54%). In 80% of cases, healing failures in the mid and distal
location occurred in old pseudoarthrosis ( >3 0 months evolution). Carpal degenerative changes
were significantly higher (p < 0,01) in patients with not healed pseudoarthrosis. The location
and the age of the pseudoarthrosis appear to be important prognostic factors. The Matti-Russe
technique has limitations when is performed either in proximal pseudoarthrosis or in the presence
of advanced radiocarpal osteoarthritis
Acute Colchicine-induced Neuromyopathy in a Patient Treated With Atorvastatin and Clarithromycin
Neuromyopathy is a rare side effect of chronic colchicine therapy, especially without renal impairment. Drugs interacting with colchicine metabolism through CYP3A4 can accelerate accumulation and toxicity. We describe a case of an interaction between atorvastatin, clarithromycin and colchicine resulting in acute neuromyopathy.
Learning points: Colchicine has a narrow therapeutic window, and therefore, often produces side effects.Special caution should be adopted if patients with renal disease and concomitant medications are given colchicine.Before prescribing colchicine, the clinical history, including previous medications and conditions, should be carefully considered
The diagnosis of hereditary angioedema: family caregivers’ experiences
The aim of this study was to understand the experiences of family caregivers in the process of diagnosing hereditary angioedema. An interpretive and qualitative research methodology based on Gadamer’s philosophical hermeneutics was carried out. Data collection took place between May 2015 and August 2016 and included a focus group and in-depth interviews with 16 family caregivers. Two themes define the experiences of family caregivers: “Family life focuses on identifying the problem” and “Discovering and coping with a complex diagnosis.” The process of diagnosis generates fear, anxiety, uncertainty, and incomprehension. Family caregivers are the main support for patients diagnosed with hereditary angioedema. As they share in the patients’ suffering, they need a diagnosis to be established to be able to cope with the disease and offer support. Family health nurses can contribute to improving the coping process in this phase of the disease
Extensibility of adaptation capabilities in the CAIN content adaptation engine
Also published online by CEUR Workshop Proceedings (CEUR-WS.org, ISSN 1613-0073)This paper describes the extensibility mechanism
that has been incorporated to the CAIN Adaptation Engine, that
provides audiovisual content adaptation based on user
preferences, network capabilities and terminal limitations. The
integration of new adaptation modules needs no code
modifications in the core system, so it does not have to be
recompiled for adding or modifying adaptation modules.This work is partially supported by the European Commission
6th Framework Program under project FP6-001765
(aceMedia). This work is also supported by the Ministerio de
Ciencia y Tecnología of the Spanish Government under
project TIN2004-07860 (MEDUSA) and by the Comunidad
de Madrid under project P-TIC-0223-0505 (PROMULTIDIS).
The authors want to thank Víctor Fernández-Carbajales for
successful testing of the extensibility mechanism
Analysis of the decrease of the apparent young's modulus of advanced high strength steels and its effect in bending simulations
In this paper the evolution of the Young’s Modulus (E) during unloading with plastic deformation has been studied for different Dual-Phase AHSS from DP780 to DP1400. During unloading, all the DP steels studied showed the presence of microplasticity so an Apparent Young’s Modulus (EA) has been defined. Although that in all cases EA decreased with a non-linear behavior as the plastic strain was increased, it has been observed that the final percentage of decrease seems to be related to the microstructure of DP steels. As the ferrite content increased as in the lower strength DP steels, the reduction of EA is larger, reaching a 21%.
The introduction of the variation of the elastic response during unloading in the simulation of a bending operation has allowed obtaining an improvement of the accuracy in springback prediction in all the DP steels studied. For the low strength DP steels the final shape obtained by simulation is in fact the same than the real one. As the strength of steel is increased, the accuracy is less, especially in the DP 1400 steel, in which differences in bending angle higher than a 15% are still found.Postprint (published version
Energy transfer in two-wave mixing quasi-degenerated in photorefractive crystals
Wave equations describing the quasi-degenerated two-beam coupling in the photorefractive crystals for high frequency gratings have been solved. In the case of the quasi-degenerate two-beam coupling, equations depend upon the coupling coefficient, the response time of the medium, the input beams frequencies, the absorption coefficient and the input intensity ratio. The response time of the medium is function of the diffusion field, the drift field, the saturation field and the concentration ratio, i.e., the ratio between NA density of acceptor impurities and ND density of donor impurities. The effect of these parameters on the gain has been studied in details.Facultad de Ciencias Exacta
Energy transfer in two-wave mixing quasi-degenerated in photorefractive crystals
Wave equations describing the quasi-degenerated two-beam coupling in the photorefractive crystals for high frequency gratings have been solved. In the case of the quasi-degenerate two-beam coupling, equations depend upon the coupling coefficient, the response time of the medium, the input beams frequencies, the absorption coefficient and the input intensity ratio. The response time of the medium is function of the diffusion field, the drift field, the saturation field and the concentration ratio, i.e., the ratio between NA density of acceptor impurities and ND density of donor impurities. The effect of these parameters on the gain has been studied in details.Facultad de Ciencias Exacta
Plasmon enhanced energy-transfer up-conversion in Yb3+-Er3+ co-doped LiNbO3 crystal
We have analyzed the effect of linear chains of metallic Ag nanoparticles on the optical properties of a periodically poled Yb 3+ -Er 3+ co-doped LiNbO 3 crystal. By exploiting the broad plasmonic response supported by linear chains of strongly coupled Ag nanoparticles, we demonstrate a 50% of enhancement of the up-converted Er 3+ emission under excitation in the f-f transition of Yb 3+ ions. The observed intensification is explained in terms of the broad plasmonic spectral response supported by the Ag chains, which overlaps both the Er 3+ visible emissions and the Yb 3+ absorption band, and the two-photon character of the Yb 3+ → Er 3+ energy-transfer up-conversion process. The results are of interest for applications involving luminescence up-conversion such as sensing, solar energy conversion, biological imaging or solid-state nanolasersThis work has been supported by the Spanish Ministry of
Economy and Competitiveness (MINECO) under project MAT2013-
43301-R and Comunidad de Madrid under grant S2013/MIT-274
Promoting dignified end-of-life care in the emergency department: a qualitative study
Background: Preservation of a dying person’s dignity in the emergency department (ED) is fundamental for the patient, his/her relatives and healthcare professionals. The aim of this study was to explore and interpret physicians’ and nurses’ experiences regarding conservation of dignity in end-of-life care in dying patients in the ED.
Methods: A qualitative study based on the hermeneutic phenomenological approach, was carried out in the emergency department of two general hospitals. A total of 16 nurses and 10 physicians participated in the study. Data collection included 12 individual in-depth interviews and 2 focus groups.
Results: The findings revealed that two themes represent the practices and proposals for the conservation of dignity in the emergency department: dignified care in hostile surroundings and the design of a system focused on the person’s dignity.
Conclusion: Dignifying treatment, redesigning environmental conditions, and reorienting the healthcare system can contribute to maintaining dignity in end-of-life care in the ED
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