63 research outputs found
Depth of thermal penetration in straight grinding
Unlike the usual numerical FEM approach to determine the thermally affected layer during the grinding process, we propose a simple analytical approach to estimate the depth of thermal penetration. For this purpose, the one-dimensional definition of depth of thermal penetration is applied to the two-dimensional heat transfer models of straight grinding. A method for computing the depth of thermal penetration in these two-dimensional models is derived and compared to the one-dimensional approximation. For dry grinding, it turns out that the one-dimensional approximation is quite accurate when we consider a moderate percentage in the temperature fall beneath the surface, regardless the type of heat flux profile entering into the workpiece (i.e., constant, linear, triangular, or parabolic). In wet grinding, the latter is true if we consider a constant heat flux profile and a high Peclet number, i.e., Pe > 5. Finally, the one- and two-dimensional approaches calculating analytically the depth of thermal penetration have been compared to the temperature field numerically evaluated by a three-dimensional FEM simulation given in the literature, obtaining a quite good agreement
Light-Harvesting Properties of a Subphthalocyanine Solar Absorber Coupled to an Optical Cavity
Autosomal recessive cerebellar ataxias
Autosomal recessive cerebellar ataxias (ARCA) are a heterogeneous group of rare neurological disorders involving both central and peripheral nervous system, and in some case other systems and organs, and characterized by degeneration or abnormal development of cerebellum and spinal cord, autosomal recessive inheritance and, in most cases, early onset occurring before the age of 20 years. This group encompasses a large number of rare diseases, the most frequent in Caucasian population being Friedreich ataxia (estimated prevalence 2–4/100,000), ataxia-telangiectasia (1–2.5/100,000) and early onset cerebellar ataxia with retained tendon reflexes (1/100,000). Other forms ARCA are much less common. Based on clinicogenetic criteria, five main types ARCA can be distinguished: congenital ataxias (developmental disorder), ataxias associated with metabolic disorders, ataxias with a DNA repair defect, degenerative ataxias, and ataxia associated with other features. These diseases are due to mutations in specific genes, some of which have been identified, such as frataxin in Friedreich ataxia, α-tocopherol transfer protein in ataxia with vitamin E deficiency (AVED), aprataxin in ataxia with oculomotor apraxia (AOA1), and senataxin in ataxia with oculomotor apraxia (AOA2). Clinical diagnosis is confirmed by ancillary tests such as neuroimaging (magnetic resonance imaging, scanning), electrophysiological examination, and mutation analysis when the causative gene is identified. Correct clinical and genetic diagnosis is important for appropriate genetic counseling and prognosis and, in some instances, pharmacological treatment. Due to autosomal recessive inheritance, previous familial history of affected individuals is unlikely. For most ARCA there is no specific drug treatment except for coenzyme Q10 deficiency and abetalipoproteinemia
Quantum control of tunable-coupling transmons using dynamical invariants of motion
We analyze the implementation of a fast nonadiabatic CZ gate between two transmon qubits with tunable coupling. The gate control method is based on a theory of dynamical invariants which leads to reduced leakage and robustness against decoherence. The gate is based on a description of the resonance between the 11 and 20 using an effective Hamiltonian with the six lowest energy states. A modification of the protocol allows us to take into account the higher-order perturbative corrections of this effective model. This enables a gate fidelity several orders of magnitude higher than other quasiadiabatic protocols, with gate times that approach the theoretical limit.We acknowledge financial support from the Spanish Government through PGC2018-094792-B-I00 (MCIU/AEI/FEDER,UE), CSIC Research Platform PTI-001, and by Comunidad de Madrid-EPUC3M14 and CAM/FEDER Project No. S2018/TCS-4342 (QUITEMAD-CM). H E acknowledges the Spanish Ministry of Science, Innovation and Universities for funding through the FPU Program (FPU20/03409). E T acknowledges the Ramón y Cajal Program (RYC2020-030060-I)
Estudio crÃtico de los Ãndices de severidad y la superficie afectada por el incendio de Sierra de Luna (Zaragoza)
Para la determinación del área quemada y la severidad asociada del incendio de Sierra de Luna (Zaragoza), ocurrido el 4 de julio de 2015, se han calculado tres Ãndices espectrales derivados de Landsat-8: NDVI, NBR y BAI. Comparando los resultados obtenidos por cada uno de ellos, en un incendio con extensas zonas de cultivo entre zonas arboladas, se ha determinado que la combinación de ΔNBR y BAI mejora sustancialmente la determinación del área realmente quemada, tanto en su perÃmetro exterior como en las zonas aisladas no quemadas de su interior. Para el cálculo de la severidad, se propone una metodologÃa basada en el análisis de las diferencias de NBR, antes y después del incendio, y su combinación con el BAI, en función del valor previo al incendio de los Ãndices NBR y de NDVI
Depth estimation improvement in 3D integral imaging using an edge removal approach
A new depth estimation method for 3D reconstruction in a synthetic aperture integral imaging framework is presented. This
method removes the edges of the objects in the elemental images when the objects are in focus. This strategy aims to compensate
for the noise that objects focused close to the cameras can introduce into the photo-consistency measure of objects
at higher depths. Furthermore, a photo-consistency criterion is applied combining a defocus and a correspondence measure,
and a depth regularization method which smooths noisy depth results for the case of object surfaces. The proposed method
obtains consistent results for any type of object surfaces as well as very sharp boundaries. Experimental results show that
our method reduces the noise in the object edges and gives rise to an improvement in the depth map results in relation to the
other methods shown in the comparative analysis
Linkage analysis in Usher syndrome type I (USH1) families from Spain.
Usher syndrome (USH) is an autosomal recessive hereditary disorder characterised by congenital sensorineural hearing loss and gradual visual impairment secondary to retinitis pigmentosa (RP). The disorder is clinically and genetically heterogeneous. With regard to Usher type I (USH1), several subtypes have been described, the most frequent being USH1B located on chromosome 11q13.5. Of 18 USH1 families studied by linkage analysis, 12 (67%) showed significant lod score values for locus D11S527 (Zmax=14.032, theta=0.000) situated on chromosome 11q. Our findings suggest considerable genetic heterogeneity in the Spanish USH1 population. It is important to note that one of our families linked to the USH1B locus shows interesting intrafamilial clinical variability. As regards the remaining six USH1 families, the linkage analysis did not provide conclusive data, although two of them show slight linkage to markers located on chromosome 3q (Zmax=1.880, theta=0.000 for D3S1279), the same location that had previously been assigned to some USH3 families
Gastrointestinal physiological changes and their relationship to weight loss following the POSE procedure.
BACKGROUND: Primary Obesity Surgery Endolumenal (POSE) is a novel bariatric endoscopic procedure that has been shown to reduce weight safely through 12 months. The study investigated potential mechanisms of weight loss following POSE. METHODS: Patients with class I-II obesity received transmural plications in the gastric fundus and distal gastric body. Patients were evaluated at baseline and at 2- and 6-month follow-up with gastric-emptying (GE) scintigraphy, a validated test of intake capacity (kcal) and plasma glucose homeostasis hormones/gastrointestinal peptides. Weight was recorded through 15 months. Mean data and 95 % CIs are reported. Regression modeling assessed variables that influenced total weight loss (%TWL) and excess weight loss (%EWL). RESULTS: POSE was performed on 18 patients (14 F/4 M); mean age 39 years (34-44), body mass index (BMI, kg/m(2)) 36 (95 % CI, 35; 37). At 15 months (n = 15), mean TWL was 19.1 ± 6.6 % (15.5; 22.8) and EWL was 63.7 ± 25.1 % (49.8; 77.6). At 2 and 6 months (n = 18), intake capacity decreased significantly from 901 (685; 1117) to 473 (345; 600) and 574 kcal (418; 730), respectively (p < 0.001). At 2 months, GE was delayed but returned to baseline levels at 6 months (n = 18). Glucose/insulin ratio improved (p < 0.05). Postprandial decrease in ghrelin was enhanced (p = 0.03) as well as postprandial increase in PYY (p = 0.001). The best model for EWL prediction 15 months after POSE (R (2): 66 %, p = 0.006) included pre-POSE BMI, post-POSE GE, and postprandial PYY increase. CONCLUSIONS: The POSE procedure was followed by significant sustained weight loss and improved glucose homeostasis and satiation peptide responses. Weight loss following POSE may be mediated through changes in gastrointestinal neuro-endocrine physiology.Manuscript development was financially supported by USGI Medical, Inc., US
Tratamiento endoscópico de la obesidad: Técnica POSE utilizando la plataforma endoscópica sin incisiones (IOP). Estudio piloto prospectivo: Eficacia clÃnica y repercusión fisiológica
Está estructurada siguiendo las directrices de la normativa para la Presentación de tesis doctorales como un compendio de Publicaciones aprobado por el Consejo del Departamento de Medicina de la Universidad de Barcelona.
ArtÃculos de la tesis:
ARTICULO 1.
Early Experience with the Incisionless Operating Platform
TM (IOP) for the Treatment of Obesity. The Primary Obesity Surgery Endolumenal (POSE) Procedure.
J. C. Espinós & R. Turró & A. Mata & M. Cruz & M. da Costa
& V. Villa & J. N. Buchwald & J. Turró
Obesity Surgery. 2013 Sep; 23(9):1375-83
ARTICULO 2.
Gastrointestinal Physiological Changes and Their Relationship to Weight Loss Following the POSE Procedure.
J. C. Espinós & R. Turró & G. Moragas & A. Bronstone &
J. N. Buchwald & F. Mearin & A. Mata & H. Uchima & J. Turró & S. Delgado-Aros.
Obesity Surgery. DOI 10.1007/s11695-015-1863-8
En el estudio 1 "Early Experience with the Incisionless Operating PlatformTM(IOP) for the Treatment of Obesity. The Primary Obesity Surgery Endolumenal (POSE) Procedure" se realiza el seguimiento de una serie consecutiva de 45 pacientes con obesidad tipos 1, II y III a los que se les realiza la intervención endoscópica "POSE" con la plataforma endoscópica "IOP" como tratamiento primario de su obesidad. Es la primera serie publicada a nivel mundial utilizando la técnica POSE como tratamiento primario de la obesidad.
Los resultados confirman las hipótesis de realización y seguridad de la técnica al conseguirse realizar en el 100% de los casos con un tiempo medio de 63 minutos, con alta antes de las 24 horas en todos los casos y solo dos interconsultas por dolor en las primeras 48 horas como efectos adversos.
La media de Porcentaje de sobrepeso perdido fué de 49,4+-21 % y del % de peso total de un 15,5+-6,1, resultados muy similares a los de las distintas técnicas quirúrgicas en el mismo plazo de tiempo.
En el estudio 2 se realiza un estudio de capacidad de ingesta calórica (test de saciedad), estudio de vaciamiento gástrico y de hormonas que participan en los mecanismos de hambre-saciedad (leptina, PYY, Ghrelina, péptido c, insulina, Glucosa) antes y a los 2 y seis meses post tratamiento endoscópico POSE de la obesidad. Se estudian 18 pacientes y se evidencia que a los 15 meses de seguimiento la pérdida de peso llega al 60% del sobrepeso y al 20 % del peso total. Se evidencia una disminución de casi el 50 % de la capacidad de ingesta calórica a los 2 y 6 meses con normalización y mejora de los valores basales y tras ingesta de glucosa, péptido c, insulina, grhelina y PYY.
Se concluye que:
1.- La utilización de la plataforma endoscópica IOP para la realización de plicaturas en estómago (Método POSE) como tratamiento primario de la obesidad, es una técnica realizable en un 100% de los casos en un tiempo limitado con muy buena tolerancia y sin efectos secundarios.
2. Los pacientes sometidos a este tratamiento presentan sensación de saciedad precoz y presentan una pérdida de peso significativa a los 6 meses y que se mantiene y aumenta a los 15 meses.
3.- Los mecanismos fisiológicos de acción del método POSE pasan por la disminución de la adaptabilidad del fundus gástrico, provocando una disminución de la capacidad de ingesta calórica. A este hecho se acompaña una disminución basal de la PYY pero con un importante aumento postpandrial. Como conclusión final, el método POSE es una técnica prometedora en el tratamiento endoscópico de la obesidad y reúne todas las condiciones requeridas de eficacia y seguridad tanto de las técnicas endoscópicas como de las quirúrgicas. Los estudios de seguimiento a largo plazo y los estudios comparativos controlados con otras técnicas permitirán delimitar la población de pacientes que se beneficiará más de esta técnica.Obesity Endoscopic treatment. POSE with the endoscopic Incisionless platform (10P). PILOT PROSPECTIVE STUDY. Clinical efficacy and physiological repercussion.
This doctoral thesis is structured according to the guidelines of the rules for the Presentation of doctoral thesis as a compendium of Publications approved by the Council of the Department of Medicine of the University of Barcelona.
Articles of the thesis:
ARTICLE 1.
Early Experience with the Incisionless Operating Platform
TM (10P) for the Treatment of Obesity. The Primary Obesity Surgery Endolumenal (POSE) Procedure.
J. C. EspinOs & r. TurrO A. Mata M. Cruz & M. da Costa & V. Villa & J. N. Buchwald & j. TurrO Obesity Surgery. 2013 Sep; 23 (9): 1375-83
ARTICLE 2.
Gastrointestinal Physiological Changes and Their Relationship to Weight Loss Following the POSE Procedure.
J. C. Espin6s & r. TurrO & g. Moragas & A. Bronstone &J. N. F. Mearin, Buchwald & H. Uchima & A. Mata & j. TurrO & S. delgado-Aros.
Obesity Surgery. DOI 10.1007/s11695-015-1863-8
Study 1: We analyze a series of 45 patients to whom we performed the endoscopic intervention "POSE" with the endoscopic platform "10P" as primary treatment for their obesity. It is the first series published worldwide using the POSE as primary treatment of obesity
The results confirm the hypothesis of performance and safety of the technique to be performed in 100% of cases with an average time 63 minutes, with no side effects.
The average percentage of overweight lost was 49, 4 ± 21% and % of total weight of 15, 5 ± 6, 1, results very similar to those of the different surgical techniques in the same time frame.
In the second paper we performed a study of the caloric intake capacity (test of satiety), a study of gastric emptying and hormones involved in the mechanisms of hunger and satiety (leptin, PYY, ghrelin, insulin, c-peptide, glucose) before and 2 and six months post POSE endoscopic treatment of obesity. We studied 18 patients and there was evidence that 15 months weight loss reaches 60% of overweight and 20% of the total weight. A decrease of almost 50% of the caloric intake capacity at 2 and 6 months with standardization and improvement of the baseline and after ingestion levels of glucose, c-peptide, insulin, ghrelin and PYY happened after the POSE procedure.
It is concluded that:
1. The use of endoscopic 10P platform for the realization of plication's in stomach (method POSE) as primary treatment of obesity is a workable technique in 100% of cases in a time-limited with very good tolerance and without side effects.
2. Patients undergoing this treatment have feeling of early satiety and presented a significant weight loss at six months and stay and increases up to 15 months.
3. The physiological action of the POSE method mechanisms go through the decrease of the adaptability of the fundus of the stomach, causing a decrease in caloric intake capacity. This fact is accompanied by a basal decrease the PYY but with an important increase in others.
As a final conclusion, the POSE method is a promising technique in the Endoscopic treatment of obesity. Long-term follow-up and controlled studies will allow delimiting the population of patients that will benefit more of this technique
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