Francisco Hernandez V - Academia.edu (original) (raw)

Papers by Francisco Hernandez V

We show that Einstein's main equations for stationary axisymmetric fields in vacuum are equiv... more We show that Einstein's main equations for stationary axisymmetric fields in vacuum are equivalent to the motion equations for bosonic strings moving on a special nonflat background. This new representation is based on the analysis of generalized harmonic maps in which the metric of the target space explicitly depends on the parametrization of the base space. It is shown that

Resumen. El artículo analiza la oposición en el régimen autoritario y los recursos políticos que ... more Resumen. El artículo analiza la oposición en el régimen autoritario y los recursos políticos que ella dispone, examinando los centros de estudios o think tank que hubo en Chile en este período, en los cuales trabajaron centenares de profesionales y destacados políticos, quienes cumplieron importantes funciones que favorecieron el desarrollo de la oposición. Pone especial atención a la Corporación de Investigaciones Económicas para Latinoamérica (Cieplan), el principal centro de investigación económica durante la dictadura, cuyos investigadores tuvieron un activo protagonismo político y ocuparon la dirección económica del gobierno del presidente Patricio Aylwin (1990Aylwin ( -1994. Se concluye que el enorme poder de los centros de estudios creó un ámbito separado de los partidos y promovió una lógica de expertos que no favoreció el desarrollo político en democracia.

Lecture Notes in Computer Science, 2008

We present a generic and light-weight Grid workflow execution engine made available as a Grid ser... more We present a generic and light-weight Grid workflow execution engine made available as a Grid service. A long-term goal is to facilitate the rapid development of application-oriented end-user workflow tools, while providing a high degree of Grid middleware-independence. The workflow engine is designed for workflow execution, independent of client tools for workflow definition. A flexible plugin-structure for middleware-integration provides a strict separation of the workflow execution and the processing of individual tasks, such as computational jobs or file transfers. The light-weight design is achieved by focusing on the generic workflow execution components and by leveraging state-of-theart Grid technology, e.g., for state management. The current prototype is implemented using the Globus Toolkit 4 (GT4) Java WS Core and has support for executing workflows produced by Karajan. It also includes plugins for task execution with GT4 as well as a high-level Grid job management framework. ⋆

Matéria (Rio de Janeiro), 2009

Propiedades de adsorción en zeolitas con anillos de 8 miembros I. Microporosidad y superficie ext... more Propiedades de adsorción en zeolitas con anillos de 8 miembros I. Microporosidad y superficie externa CORONA I , O.L.; HERNÁNDEZ I , M.A.; HERNÁNDEZ I , F.; ROJAS II , F.; PORTILLO III , R.; LARA II , V.H.; CARLOS IV , F.M.

Database : the journal of biological databases and curation, 2015

Being able to assess the quality and level of completeness of data has become indispensable in ma... more Being able to assess the quality and level of completeness of data has become indispensable in marine biodiversity research, especially when dealing with large databases that typically compile data from a variety of sources. Very few integrated databases offer quality flags on the level of the individual record, making it hard for users to easily extract the data that are fit for their specific purposes. This article describes the different steps that were developed to analyse the quality and completeness of the distribution records within the European and international Ocean Biogeographic Information Systems (EurOBIS and OBIS). Records are checked on data format, completeness and validity of information, quality and detail of the used taxonomy and geographic indications and whether or not the record is a putative outlier. The corresponding quality control (QC) flags will not only help users with their data selection, they will also help the data management team and the data custodi...

This paper presents a non-parametric method to extract a very short feature vector from the curva... more This paper presents a non-parametric method to extract a very short feature vector from the curvature function of a planar shape. Curvature is adaptively calculated using a new procedure that removes noise from the contour without missing relevant points. Then, its Fourier transform is projected onto a set of vectors, which have been chosen to be as representative as possible, to obtain the similarity between the input object and each vector of the set. These similarity values are the elements of the feature vector. The proposed method is very fast and classi"cation has proven that the representation is good.

Pediatrics, 2014

Parapneumonic empyema (PPE) is a frequent complication of acute bacterial pneumonia in children. ... more Parapneumonic empyema (PPE) is a frequent complication of acute bacterial pneumonia in children. There is limited evidence regarding the optimal treatment of this condition. The aim of this study was to compare the efficacy of drainage plus urokinase versus video-assisted thoracoscopic surgery in the treatment of PPE in childhood. This prospective, randomized, multicenter clinical trial enrolled patients aged <15 years and hospitalized with septated PPE. Study patients were randomized to receive urokinase or thoracoscopy. The main outcome variable was the length of hospital stay after treatment. The secondary outcomes were total length of hospital stay, number of days with the chest drain, number of days with fever, and treatment failures. The trial was approved by the ethics committees of all the participating hospitals. A total of 103 patients were randomized to treatment and analyzed; 53 were treated with thoracoscopy and 50 with urokinase. There were no differences in demogra...

Reumatología Clínica, 2007

Reumatología Clínica, 2006

Background and objective: Congenital complete atrioventricular heart block (CHB) is due to the le... more Background and objective: Congenital complete atrioventricular heart block (CHB) is due to the lesion of the cardiac conduction system by specific transplacental antibodies of maternal origin. In adults with systemic lupus erythematosus (SLE), cardiac toxicity is very questionable and has been related to treatment with synthetic antimalarial drugs (AM). Here we evaluate, in our geographic area, the presence of non congenital CHB in adult patients with SLE and its possible association with AM treatment. Patients and methods: The frequency of CHB has been studied revising the clinical records of 595 SLE patients followed at the Unit for Systemic Diseases. Results: Five women (0.8% of the total series) suffered from CHB (2 patients developed it during a lupic crisis). All were on treatment with AM (100 versus 60% of the rest of the series) and maintained a dose of 250 mg/day (except one, with a dose of 500 mg/day) for a mean period of 90 months. The accumulated mean dose of AM was 753 g. Three patients developed cardiac insufficiency; 2 nephropathy; 2 myopathy; and one maculopathy. As accompanying processes we detected Sjögren's syndrome (2) and hypothyroidism (3). The frequency of HLA DR3, positive in 80% of the cases, is higher than observed in the total series, 34% (p = 0.053). Conclusions: We detected the presence of CHB in 0.8% of SLE patients. They were all treated with AM. We did not verify any relationship with anti-ENA (anti-Ro/La and anti-RNP) antibodies, as communicated by others, but rather a trend to the association with HLA DR3 (at the limit of statistical significance).

International Journal of Polymeric Materials, 2000

The relevance of controlling the chemical structure, thermal stability, composition and the poros... more The relevance of controlling the chemical structure, thermal stability, composition and the porosity, of microwave-cured polymeric denture-molds is a key parameter if some degree of control of the corresponding adhesion among components is to be achieved. Different microwave-cured only polymer blends (Epoxy resin + Hardener) for producing denture molds were characterized by different techniques and compared to microwave-cured composites, also

European Journal of Pediatric Surgery, 2014

Aim The ideal repair of esophageal atresia (EA) is primary anastomosis with closure of the fistul... more Aim The ideal repair of esophageal atresia (EA) is primary anastomosis with closure of the fistula if present. Long gap or local circumstances prompt other procedures that occasionally lead to disastrous complications. The aim of this study was to analyze the management of these complications in a tertiary referral center. Patients and Methods A retrospective review of patients treated for EA between 1993 and 2013 was conducted. Both the patients were primarily treated by us, and referrals from elsewhere after two or more failed operations were included. Results In total, 23 patients were included (3/176 cases of EA treated primarily by us and 20 referrals). Of the 23 patients, 6 had type I EA, 15 type III (four long gaps), 1 type IV, and 1 type V. Cardiac anomalies were associated in seven cases, duodenal atresia in three, and Down syndrome in two patients. Primary anastomosis was initially achieved in 12 patients. Primary or secondary Foker lengthening was used in seven cases. The causes of the failure were anastomotic leaks in nine, unmanageable strictures in seven, and refistulization in five patients. These patients required 66 reoperations (median of 3 [2-7]) before inclusion in the study. Radical tertiary treatment consisted of 15 esophageal replacements (11 colonic grafts and 4 gastric pull-ups), and 1 esophageal-gastric disconnection. Five patients previously treated with esophageal replacement and referred for graft problems required 13 interventions. Two families did not give consent for one replacement and one disconnection. Complications appeared in 12 patients, and 9 additional operations were required in 7 patients. With a follow-up of 31 months (range, 4-139 months) 15 patients take all their meals per os, 5 occasionally use the gastrostomy, and 2 and 1 are fed exclusively via gastrostomy or jejunostomy. All tracheoesophageal fistulas were closed, but 15 cases are below p3 for weight and 12 for height. Three patients (13%) ultimately died 32 months (range, 9-56 months) after the first operation (due to aspiration in one, and for causes unrelated to it in the other two [tracheostomy obstruction and Guillain-Barré syndrome]). Conclusions When repeated complications appear after EA repair, radical surgical attitudes may be justified. If esophageal continuity cannot be reestablished, the native esophagus may have to be discarded and replaced. Many complications should be expected, but the end result can be good. These patients should be referred to centers with large experience in the management of this complex condition.

Medicina Clínica, 2004

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Solar Energy Materials and Solar Cells, 2009

Poly(3-hexylthiophene) (P3HT) and poly(3-octylthiophene) (P3OT) were synthesized by direct oxidat... more Poly(3-hexylthiophene) (P3HT) and poly(3-octylthiophene) (P3OT) were synthesized by direct oxidation of the respective monomers with FeCl 3 as oxidant/catalyst. It was observed that the type of monomer affected the molecular weight and polydispersity as well as degree of regioregularity of the polymer, measured by size exclusion chromatography and by 1 H nuclear magnetic resonance, respectively. Homogeneous P3HT and P3OT films were prepared by spin-coating technique with different polymer concentration in solutions. Morphology study with atomic force microscopy indicates the cluster size difference between P3HT and P3OT films. Optical absorption properties of the polymeric films were analyzed in pristine and doped state. The electrochemical characterization of the poly (3-alquilthiophenes) (P3Ats) films showed two oxidation peaks, one at 0.35 V vs. Ag/AgCl, and the second one at 0.8 V vs. Ag/AgCl. The colors of the film at these two potentials were black and blue, respectively.

Journal of Pediatric Surgery, 2014

Background: Both esophageal atresia (EA) and duodenal atresia (DA) involve deficient anti-reflux ... more Background: Both esophageal atresia (EA) and duodenal atresia (DA) involve deficient anti-reflux barrier, poor esophageal function and eventually, duodenogastric reflux. This study aims at examining the upper gastrointestinal functional status in a cohort of patients with both EA and DA. Methods: A retrospective survey of patients treated for EA and DA between 1965 and 2012 was conducted. Clinical charts, office visits, imaging, upper gastrointestinal endoscopy and esophageal pH metry/impedance were used to assess the long-term condition of the esophagus, the presence of gastroesophageal reflux disease (GERD) and/or the need for fundoplication. Results: Twenty out of 581 patients treated for EA had associated DA. Ten/twenty children survived; 1 had primary esophageal replacement. With a median follow-up of 9 years, 8/9 had complicated outcomes and 5 still suffered digestive ailments: 2 GER; 1 eosinophilic esophagitis; 1 nodular gastritis, and 1 wrap herniation. A total of 10 procedures were performed: 8 fundoplications, 1 esophagogastric dissociation and 1 replacement with colon. Discussion: The association of EA with DA involves a poor upper digestive function with high risks of GERD and fundoplication failure. The lifelong synergistic play of esophageal, gastric and duodenal dysfunctions in these patients prompts long-term follow-up, and eventually active treatment.

Archivos de Bronconeumología ((English Edition)), 2008

Despite advances in the treatment of patients with pulmonary arterial hypertension (PAH), surviva... more Despite advances in the treatment of patients with pulmonary arterial hypertension (PAH), survival has not improved greatly (is still very affected). Imatinib, an antagonist of platelet-derived growth factor with antiproliferative activity, has been effective in experimental models and clinically in several published reports. We report the results of imatinib therapy in 4 patients with PAH (functional class IV) who were refractory to treatment with drug combinations for this condition. The final outcome was favorable in only 1 of the 4 cases. In this case, the patient was in functional class III and his hemodynamic parameters had improved significantly within 5 months after starting therapy. However, the patient died as a result of severe toxic hepatitis in which imatinib may have played a role. The present report adds to the few already in the literature (4 cases) and suggests that care should continue to be shown when using imatinib to treat PAH.

Archivos de Bronconeumología, 2008

La hipertensión arterial pulmonar (HAP) se caracteriza por la constricción y oclusión de los vaso... more La hipertensión arterial pulmonar (HAP) se caracteriza por la constricción y oclusión de los vasos pulmonares, que determinan el aumento de las resistencias vasculares. Puede ser idiopática (HAPI) o asociarse a diversos procesos. Aunque el pronóstico de la HAPI ha mejorado en la última década gracias a los nuevos fármacos 1-10 , la supervivencia a los 5 años aún ronda el 50% 11 . Existen pruebas experimentales de la eficacia del imatinib 10,12-14 , corroboradas por la descripción de casos con respuesta favorable . Nuestro grupo ha tratado con imatinib a 4 pacientes. En la literatura médica (búsqueda en la base de datos bibliográficos MEDLINE con las palabras clave "imatinib" y "pulmonary hypertension", entre enero de 2000 y 23 de octubre de 2007), sólo hemos encontrado la descripción de otros 4 pacientes tratados. Dada la escasa experiencia existente, creemos importante comunicarlos.

Reumatología Clínica, 2009

Medicina Clínica, 2010

To study severe infectious complications in a cohort of patients with systemic lupus erythematosu... more To study severe infectious complications in a cohort of patients with systemic lupus erythematosus (SLE). Retrospective study of 705 patients followed from January 1980 to January 2008. Data are expressed in percentages. The frequency of severe infectious was 38.6%. The etiology was bacterial 54.4%, viric 30.4% and opportunist in 15.2% patients. Involved organs were: Lung 38.2%, kidney 48.9%, central nervous system 43%. 43.75% patients received pulsed ciclofosfamide therapy and 88.6% received glucocorticoids (39.7% pulsed). The mortality was 27.7%. At present, infection is an important cause of mortality in patients with SLE. Early diagnosis of infectious complications is very important in SLE.