Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Health Informatics J ; 29(4): 14604582231212494, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38072502

RESUMEN

The objective was to assess risk of hospitalization and mortality of comorbidities using divisive hierarchical risk clustering to advice clinical interventions. Subjects and Methods: Data from the EHR of a general population, 3799885 adults, followed by 5 years. Model were performed using Spark and Scikit-learn and accuracy for the models was analyzed. Results: The number of models generated depends in part on the number of chronic diseases included (ex testing a sample of six diseases, a total number of 397 models for all-cause mortality and 431 models for hospitalization). The estimated models offered an ordered selection for the relevant clinical variables and their estimated risk as a group and for the individual patient in the group. Accuracy was assessed according to age, sex and the cardinality of the comorbid groups. A mobile version and dashboard were developed. Conclusion: The software developed stratified hospital admission and mortality risk in clusters of chronic diseases, and for a given patient, it could advise intensifying treatment or reallocating the patient risk.


Asunto(s)
Atención a la Salud , Hospitalización , Adulto , Humanos , Comorbilidad , Enfermedad Crónica , Análisis por Conglomerados
2.
Cancer Chemother Pharmacol ; 87(4): 543-553, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33452559

RESUMEN

PURPOSE: To evaluate the health-related quality of life (HRQoL), global health status (GHS), and deterioration-free survival of an elderly population (> 70 years) with unresectable locally advanced (LAPC) or metastatic pancreatic cancer (mPC) treated with nab-paclitaxel in combination with gemcitabine. METHODS: In this open-label, single-arm, multicenter, phase II trial, patients received 4-week cycles of intravenous (i.v.) nab-paclitaxel at a dose of 125 mg/m2, followed by i.v. injections of gemcitabine at a dose of 1000 mg/m2 on days 1, 8 and 15 until disease progression or unacceptable toxicity was observed. The primary outcome was the HRQoL (deterioration-free rate at 3 months as evaluated with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30. RESULTS: Eighty patients (median age: 74.6 years) were enrolled (56 with mPC, 24 with LAPC). The percentage of patients who had not experienced deterioration at 3 months was 54.3% (95% CI 41.6-67.0%). The median (interquartile range) time until definite deterioration was 1.6 (1.1-3.7) months. The objective response rate and clinical benefit rate were achieved by 11 (13.8%, 95% CI 6.2-21.3%) and 54 patients (67.5%, 95% CI 57.2-77.8%), respectively. The median overall survival was 9.2 months (95% CI 6.9-11.5), and the median progression-free survival was 7.2 months (95% CI 5.8-8.5). Only fatigue and neutropenia demonstrated a grade 3-4 toxicity incidence > 20%. CONCLUSIONS: Our study confirms the clinical benefit of the combination of nab-paclitaxel and gemcitabine in an elderly population with pancreatic cancer in terms of improved survival and clinical response. However, we were unable to confirm a benefit in terms of quality-of-life.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Albúminas/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Desoxicitidina/análogos & derivados , Paclitaxel/administración & dosificación , Neoplasias Pancreáticas/tratamiento farmacológico , Adenocarcinoma/mortalidad , Anciano , Albúminas/efectos adversos , Desoxicitidina/administración & dosificación , Desoxicitidina/efectos adversos , Femenino , Humanos , Masculino , Paclitaxel/efectos adversos , Neoplasias Pancreáticas/mortalidad , Calidad de Vida , Gemcitabina
3.
Nanomedicine (Lond) ; 13(17): 2171-2185, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30277422

RESUMEN

AIM: Sol-gel is a suitable and advantageous method to synthesize mixed oxide nanomaterials with unique physicochemical and biological properties. MATERIALS & METHODS: In this work, TiO2-SiO2 nanopowders cogeled with platinum acetylacetonate were developed and studied in the perspective of nanomedicine. The physicochemical properties of the Pt/TiO2-SiO2 nanopowders, named NanoRa2-Pt, were evaluated in detail by means of complementary spectroscopic and microscopic tools. The nanopowder's biocatalytic efficiency in wound healing was evaluated in a Type I diabetes animal model. RESULTS: These are TiO2-SiO2 submicron mesoporous particles with variable size and shape containing ultra-small platinum nanoparticles with catalytic properties. CONCLUSION: The use of NanoRa2-Pt catalyzes the natural healing processes with a faster remodeling stage. These sols, which we call nanobiocatalysts, belong to an emerging and very promising research field known as catalytic nanomedicine.


Asunto(s)
Nanopartículas/química , Platino (Metal)/química , Dióxido de Silicio/química , Titanio/química , Cicatrización de Heridas/efectos de los fármacos , Animales , Catálisis , Complicaciones de la Diabetes/tratamiento farmacológico , Complicaciones de la Diabetes/fisiopatología , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Humanos , Masculino , Nanopartículas del Metal/química , Nanomedicina , Porosidad , Ratas , Ratas Wistar , Propiedades de Superficie
4.
Front Physiol ; 9: 404, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29867517

RESUMEN

Introduction: Focal atrial tachycardia is commonly treated by radio frequency ablation with an acceptable long-term success. Although the location of ectopic foci tends to appear in specific hot-spots, they can be located virtually in any atrial region. Multi-electrode surface ECG systems allow acquiring dense body surface potential maps (BSPM) for non-invasive therapy planning of cardiac arrhythmia. However, the activation of the atria could be affected by fibrosis and therefore biomarkers based on BSPM need to take these effects into account. We aim to analyze the effect of fibrosis on a BSPM derived index, and its potential application to predict the location of ectopic foci in the atria. Methodology: We have developed a 3D atrial model that includes 5 distributions of patchy fibrosis in the left atrium at 5 different stages. Each stage corresponds to a different amount of fibrosis that ranges from 2 to 40%. The 25 resulting 3D models were used for simulation of Focal Atrial Tachycardia (FAT), triggered from 19 different locations described in clinical studies. BSPM were obtained for all simulations, and the body surface potential integral maps (BSPiM) were calculated to describe atrial activations. A machine learning (ML) pipeline using a supervised learning model and support vector machine was developed to learn the BSPM patterns of each of the 475 activation sequences and relate them to the origin of the FAT source. Results: Activation maps for stages with more than 15% of fibrosis were greatly affected, producing conduction blocks and delays in propagation. BSPiMs did not always cluster into non-overlapped groups since BSPiMs were highly altered by the conduction blocks. From stage 3 (15% fibrosis) the BSPiMs showed differences for ectopic beats placed around the area of the pulmonary veins. Classification results were mostly above 84% for all the configurations studied when a large enough number of electrodes were used to map the torso. However, the presence of fibrosis increases the area of the ectopic focus location and therefore decreases the utility for the electrophysiologist. Conclusions: The results indicate that the proposed ML pipeline is a promising methodology for non-invasive ectopic foci localization from BSPM signal even when fibrosis is present.

5.
PLoS Comput Biol ; 14(3): e1006017, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29505583

RESUMEN

Anatomically based procedures to ablate atrial fibrillation (AF) are often successful in terminating paroxysmal AF. However, the ability to terminate persistent AF remains disappointing. New mechanistic approaches use multiple-electrode basket catheter mapping to localize and target AF drivers in the form of rotors but significant concerns remain about their accuracy. We aimed to evaluate how electrode-endocardium distance, far-field sources and inter-electrode distance affect the accuracy of localizing rotors. Sustained rotor activation of the atria was simulated numerically and mapped using a virtual basket catheter with varying electrode densities placed at different positions within the atrial cavity. Unipolar electrograms were calculated on the entire endocardial surface and at each of the electrodes. Rotors were tracked on the interpolated basket phase maps and compared with the respective atrial voltage and endocardial phase maps, which served as references. Rotor detection by the basket maps varied between 35-94% of the simulation time, depending on the basket's position and the electrode-to-endocardial wall distance. However, two different types of phantom rotors appeared also on the basket maps. The first type was due to the far-field sources and the second type was due to interpolation between the electrodes; increasing electrode density decreased the incidence of the second but not the first type of phantom rotors. In the simulations study, basket catheter-based phase mapping detected rotors even when the basket was not in full contact with the endocardial wall, but always generated a number of phantom rotors in the presence of only a single real rotor, which would be the desired ablation target. Phantom rotors may mislead and contribute to failure in AF ablation procedures.


Asunto(s)
Técnicas de Ablación/métodos , Fibrilación Atrial/fisiopatología , Biología Computacional/métodos , Técnicas de Ablación/estadística & datos numéricos , Potenciales de Acción , Fibrilación Atrial/terapia , Biología Computacional/estadística & datos numéricos , Simulación por Computador , Atrios Cardíacos/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Frecuencia Cardíaca , Humanos , Modelos Biológicos , Factores de Tiempo
6.
PLoS One ; 12(7): e0181263, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28704537

RESUMEN

Non-invasive localization of continuous atrial ectopic beats remains a cornerstone for the treatment of atrial arrhythmias. The lack of accurate tools to guide electrophysiologists leads to an increase in the recurrence rate of ablation procedures. Existing approaches are based on the analysis of the P-waves main characteristics and the forward body surface potential maps (BSPMs) or on the inverse estimation of the electric activity of the heart from those BSPMs. These methods have not provided an efficient and systematic tool to localize ectopic triggers. In this work, we propose the use of machine learning techniques to spatially cluster and classify ectopic atrial foci into clearly differentiated atrial regions by using the body surface P-wave integral map (BSPiM) as a biomarker. Our simulated results show that ectopic foci with similar BSPiM naturally cluster into differentiated non-intersected atrial regions and that new patterns could be correctly classified with an accuracy of 97% when considering 2 clusters and 96% for 4 clusters. Our results also suggest that an increase in the number of clusters is feasible at the cost of decreasing accuracy.


Asunto(s)
Complejos Atriales Prematuros/diagnóstico , Mapeo del Potencial de Superficie Corporal/métodos , Electrocardiografía/métodos , Taquicardia Atrial Ectópica/diagnóstico , Fibrilación Atrial/fisiopatología , Complejos Atriales Prematuros/fisiopatología , Simulación por Computador , Atrios Cardíacos/patología , Atrios Cardíacos/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Humanos , Procesamiento de Imagen Asistido por Computador , Taquicardia Atrial Ectópica/fisiopatología
7.
Endocr Relat Cancer ; 23(2): R71-84, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27064164

RESUMEN

In differentiated thyroid carcinoma refractory to radioactive iodine (CDT-RTI), chemotherapy has been considered for decades to be the only systemic therapy with palliative purpose. Phase II studies assessing the efficacy of different chemotherapy outlines have been published. Nevertheless, phase III studies in these tumours have not been performed. Our objective is to evaluate the effectiveness of chemotherapy in patients with CDT-RTI by a systematic review of published studies. Systematic research of the literature in Medline and Embase databases (among others) was carried out. The full texts of selected references were analysed by two independent reviewers and then assessed for risk of bias in each study. We also extracted data using specifically designed questionnaires. Later, a qualitative synthesis of results was performed and pooled data were calculated. We found that 16 studies with 473 patients published in the last 40 years were included out of 509 identified references in databases. Thirteen studies (176 patients) included data on response to treatment and histology. Four studies included 70 patients only with well-differentiated non-medullary tumours. Response rate (RR) was 22.1% (0-57%) for 13 studies, 25% for the 176 patients and 27.1% for the 70 patients, with 2.5, 3.4 and 2.8% complete responses respectively. Survival times could not be assessed or pooled due to the lack of data and heterogeneity of the studies, and was determined to have a high risk of bias. Although it has not been possible to find solid evidence about the efficacy of chemotherapy, the results shown indicate that it may have some effectiveness, although this should be proven with well-designed studies using modern drugs.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Antineoplásicos/uso terapéutico , Neoplasias de la Tiroides/tratamiento farmacológico , Adenocarcinoma/patología , Progresión de la Enfermedad , Humanos , Índice de Severidad de la Enfermedad , Neoplasias de la Tiroides/patología , Resultado del Tratamiento
8.
Chemphyschem ; 16(18): 3984-91, 2015 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-26394883

RESUMEN

Repeated and controlled immersion calorimetry experiments were performed to determine the specific surface area and pore-size distribution (PSD) of a well-characterized, microporous poly(furfuryl alcohol)-based activated carbon. The PSD derived from nitrogen gas adsorption indicated a narrow distribution centered at 0.57±0.05 nm. Immersion into liquids of increasing molecular sizes ranging from 0.33 nm (dichloromethane) to 0.70 nm (α-pinene) showed a decreasing enthalpy of immersion at a critical probe size (0.43-0.48 nm), followed by an increase at 0.48-0.56 nm, and a second decrease at 0.56-0.60 nm. This maximum has not been reported previously. After consideration of possible reasons for this new observation, it is concluded that the effect arises from molecular packing inside the micropores, interpreted in terms of 2D packing. The immersion enthalpy PSD was consistent with that from quenched solid density functional theory (QSDFT) analysis of the nitrogen adsorption isotherm.

9.
J Colloid Interface Sci ; 448: 41-50, 2015 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-25710387

RESUMEN

Fixed-bed thermodynamic CO2 adsorption tests were performed in model flue-gas onto Filtrasorb 400 and Nuchar RGC30 activated carbons (AC) functionalized with [Hmim][BF4] and [Emim][Gly] ionic liquids (IL). A comparative analysis of the CO2 capture results and N2 porosity characterization data evidenced that the use of [Hmim][BF4], a physical solvent for carbon dioxide, ended up into a worsening of the parent AC capture performance, due to a dominating pore blocking effect at all the operating temperatures. Conversely, the less sterically-hindered and amino acid-based [Emim][Gly] IL was effective in increasing the AC capture capacity at 353 K under milder impregnation conditions, the beneficial effect being attributed to both its chemical affinity towards CO2 and low pore volume reduction. The findings derived in this work outline interesting perspectives for the application of amino acid-based IL supported onto activated carbons for CO2 separation under post-combustion conditions, and future research efforts should be focused on the search for AC characterized by optimal pore size distribution and surface properties for IL functionalization.

10.
Langmuir ; 30(20): 5840-8, 2014 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-24784997

RESUMEN

In this work, batch and dynamic adsorption tests are coupled for an accurate evaluation of CO2 adsorption performance of three different activated carbons (AC) obtained from olive stones by chemical activation followed by physical activation with CO2 at varying times (i.e., 20, 40, and 60 h). Kinetic and thermodynamic CO2 adsorption tests from simulated flue gas at different temperatures and CO2 pressures are carried out under both batch (a manometric equipment operating with pure CO2) and dynamic (a lab-scale fixed-bed column operating with a CO2/N2 mixture) conditions. The textural characterization of the AC samples shows a direct dependence of both micropore and ultramicropore volume on the activation time; hence, AC60 has the higher contribution. The adsorption tests conducted at 273 and 293 K showed that when CO2 pressure is lower than 0.3 bar, the lower the activation time, the higher CO2 adsorption capacity; a ranking of ω(eq)(AC20) > ω(eq)(AC40) > ω(eq)(AC60) can be exactly defined when T = 293 K. This result is likely ascribed to the narrower pore size distribution of the AC20 sample, whose smaller pores are more effective for CO2 capture at higher temperature and lower CO2 pressure, the latter representing operating conditions of major interest for decarbonation of flue gas effluent. Moreover, the experimental results obtained from dynamic tests confirm the results derived from the batch tests in terms of CO2 adsorption capacity. It is important to highlight the fact that the adsorption of N2 on the synthesized AC samples can be considered to be negligible. Finally, the importance of proper analysis for data characterization and adsorption experimental results is highlighted for the correct assessment of the CO2 removal performance of activated carbons at different CO2 pressures and operating temperatures.

11.
Chem Soc Rev ; 43(22): 7681-717, 2014 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-24699503

RESUMEN

Alternative energy technologies are greatly hindered by significant limitations in materials science. From low activity to poor stability, and from mineral scarcity to high cost, the current materials are not able to cope with the significant challenges of clean energy technologies. However, recent advances in the preparation of nanomaterials, porous solids, and nanostructured solids are providing hope in the race for a better, cleaner energy production. The present contribution critically reviews the development and role of mesoporosity in a wide range of technologies, as this provides for critical improvements in accessibility, the dispersion of the active phase and a higher surface area. Relevant examples of the development of mesoporosity by a wide range of techniques are provided, including the preparation of hierarchical structures with pore systems in different scale ranges. Mesoporosity plays a significant role in catalysis, especially in the most challenging processes where bulky molecules, like those obtained from biomass or highly unreactive species, such as CO2 should be transformed into most valuable products. Furthermore, mesoporous materials also play a significant role as electrodes in fuel and solar cells and in thermoelectric devices, technologies which are benefiting from improved accessibility and a better dispersion of materials with controlled porosity.

12.
Langmuir ; 29(9): 3045-53, 2013 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-23402596

RESUMEN

MCM-41-type mesoporous silica was used as a support for poly(furfuryl alcohol) deposition. This material was produced by precipitation-polycondensation of furfuryl alcohol (FA) in aqueous slurry of the SiO2 support followed by controlled partial carbonization. By tuning the FA/MCM-41 mass ratio in the reaction mixture, various amounts of polymer particles were introduced on the inner and outer surface of the MCM support. The thermal decomposition of the PFA/MCM-41 composites was studied by thermogravimetry (TG) and spectroscopic techniques (DRIFT, XPS), whereas the evolution of textural parameters with increasing polymer content was investigated using low-temperature adsorption of nitrogen. The mechanism of thermal transformations of PFA deposited on the MCM-41 surface was discussed in detail. It was found that heating at a temperature of about 523 K resulted in opening of the furan rings and the formation of γ-diketone moieties, which were found to be the highest effective surface species for the adsorption of polar volatile organic compounds. A further increase in calcination temperature caused a drop in the amounts of surface carbonyls and the appearance of condensed aromatic domains.

13.
Langmuir ; 28(19): 7564-71, 2012 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-22509799

RESUMEN

Transitional metals (M) were dispersed on single-wall carbon nanohorns (M/SWCNHs, M = Fe, Co, Ni, Cu) by simple thermal treatment of the deposited metal nitrate without H(2) reduction. Nanometallic Ni particles on SWCNH were evidenced by high-resolution transmission electron microscopic observation and X-ray photoelectron spectroscopy. The nano-Ni dispersed on SWCNH showed the highest CH(4) decomposition activity; the activity of used transitional metals decreases in the order Ni ≫ Co > Fe ≫ Cu. On the other hand, the reaction rate over Ni/SWCNH was much larger than that over Ni/Al(2)O(3), and the former provided CO(x)-free H(2) and cup-stacked carbon nanotubes, while Ni/Al(2)O(3) produced CO(x) in addition to H(2). SWCNH was superior to Al(2)O(3) as the catalyst support of Ni for the CH(4) decomposition reaction.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...