Embolización de arterias prostáticas en la hiperplasia benigna de la próstata en pacientes no quirúrgicos / Embolisation of prostate arteries in benign prostatic hyperplasia in non-surgical patients

OBJETIVO: Presentar los resultados de un estudio multidisciplinar de dos hospitales terciarios, junto a los servicios de urología, sobre 102 pacientes consecutivos no candidatos a cirugía tratados durante más de 6 años, en los que se realizó embolización de arterias prostáticas para el tratamiento de la hiperplasia benigna. MATERIAL Y MÉTODOS: Desde diciembre de 2012 a febrero de 2019, 102 pacientes con síntomas de hiperplasia benigna de la próstata (HBP) no candidatos a cirugía o que la rechazaron explícitamente, con una edad media de 73,9 años (rango 47,5-94,5), fueron sometidos a embolización prostática. Se llevó a cabo un seguimiento de estos a través de cuestionarios sobre la sintomatología urinaria, función sexual e impacto en la calidad de vida, así como la medición del volumen prostático, uroflujometría y antígeno prostático específico (PSA) al mes, 3 y 6 meses y al año del procedimiento. RESULTADOS: La técnica fue exitosa en un 96% de los pacientes (76,2% bilateral y 19,8% unilateral). El tiempo de duración media del procedimiento fue de 92 minutos y el de radioscopia, de 35,2 minutos. Se demostraron cambios estadísticamente significativos (p < 0,05) en el PSA, el flujo urinario pico (Qmáx), el cuestionario QoL (Quality of life) y el International Index of Erectile Function (IPSS). El PSA disminuyó un 58% a los 3 meses respecto al valor inicial. Asimismo, el Qmáx aumentó de manera significativa en un 63% al tercer mes tras la embolización. Se obtuvo una mejoría significativa en los test QoL e IPSS, con una disminución de 3,7 puntos y 13,5 puntos de media, respectivamente, al año de seguimiento. El volumen prostático mostró una disminución no estadísticamente significativa al año, tras el tratamiento. Se han recogido una serie de complicaciones menores, que en ningún caso requirieron ingreso hospitalario. CONCLUSIONES: La embolización prostática para el tratamiento de la HPB demostró ser una técnica eficaz y segura en pacientes no candidatos a cirugía

OBJECTIVE: To present the results of a multidisciplinary study of two tertiary hospitals, together with urology services, on 102 consecutive patients not candidates for surgery treated for more than 6 years, in whom prostatic arteries were embolised for the treatment of benign hyperplasia. MATERIAL AND METHODS: From December 2012 to February 2019, 102 patients with symptoms of benign prostatic hyperplasia (BPH) not candidates for surgery or who explicitly rejected surgery, with an average age of 73.9 years (range 47.5-94.5), underwent prostatic artery embolisation. The patients were followed up by questionnaires on urinary symptoms, sexual function and impact on quality of life, as well as measurement of prostate volume, uroflowmetry and prostate specific antigen (PSA) at one, 3 and 6 months and one year following the procedure. RESULTS: The technique was successful in 96% of patients (76.2% bilateral and 19.8% unilateral). The mean duration of the procedure was 92minutes and of the radioscopy 35.2minutes. Statistically significant changes were demonstrated (p <.05) in PSA, peak urinary flow, QoL (quality of life) questionnaire and the International Index of Erectile Function (IPSS). PSA had reduced by 58% from baseline at 3 months. Similarly, the Qmax had increased significantly by 63% in the third month following embolisation. A significant improvement in the QoL and IPSS tests was achieved, with a reduction of 3.7 points and a mean 13.5 points, respectively, at one year's follow-up. Prostate volume showed a non-statistically significant decrease at follow-up of one year following treatment. A series of minor complications was collected, no case of which required hospital admission. CONCLUSIONS: Prostatic embolisation for the treatment of BPH proved an effective and safe technique in patients who were not candidates for surgery

Embolisation of prostate arteries in benign prostatic hyperplasia in non-surgical patients. / Embolización de arterias prostáticas en la hiperplasia benigna de la próstata en pacientes no quirúrgicos.

OBJECTIVE: To present the results of a multidisciplinary study of two tertiary hospitals, together with urology services, on 102 consecutive patients not candidates for surgery treated for more than 6 years, in whom prostatic arteries were embolised for the treatment of benign hyperplasia. MATERIAL AND METHODS: From December 2012 to February 2019, 102 patients with symptoms of benign prostatic hyperplasia (BPH) not candidates for surgery or who explicitly rejected surgery, with an average age of 73.9 years (range 47.5-94.5), underwent prostatic artery embolisation. The patients were followed up by questionnaires on urinary symptoms, sexual function and impact on quality of life, as well as measurement of prostate volume, uroflowmetry and prostate specific antigen (PSA) at one, 3 and 6 months and one year following the procedure. RESULTS: The technique was successful in 96% of patients (76.2% bilateral and 19.8% unilateral). The mean duration of the procedure was 92minutes and of the radioscopy 35.2minutes. Statistically significant changes were demonstrated (p <.05) in PSA, peak urinary flow, QoL (quality of life) questionnaire and the International Index of Erectile Function (IPSS). PSA had reduced by 58% from baseline at 3 months. Similarly, the Qmax had increased significantly by 63% in the third month following embolisation. A significant improvement in the QoL and IPSS tests was achieved, with a reduction of 3.7 points and a mean 13.5 points, respectively, at one year's follow-up. Prostate volume showed a non-statistically significant decrease at follow-up of one year following treatment. A series of minor complications was collected, no case of which required hospital admission. CONCLUSIONS: Prostatic embolisation for the treatment of BPH proved an effective and safe technique in patients who were not candidates for surgery.

Quantum-size effects in visible defect photoluminescence of colloidal ZnO quantum dots: a theoretical analysis.

ZnO has been known for a long time to be a highly efficient luminescent material. In the last few years, the experimental investigation of the luminescent properties of colloidal ZnO nanocrystals in the nanometer range of sizes has attracted a lot of interest for their potential applications in light-emitting diodes and other optical devices and in this work we approach the problem from a theoretical perspective. Here, we develop a simple theory for the green photoluminescence of ZnO quantum dots (QDs) that allows us to understand and rationalize several experimental findings on fundamental grounds. We study the spectrum of light emitted in the radiative recombination of a conduction band electron with a deeply trapped hole and find that the experimental behavior of this emission band with particle size can be understood in terms of quantum size effects of the electronic states and their overlap with the deep hole. We focus the comparison of our results on detailed experiments performed for colloidal ZnO nanoparticles in ethanol and find that the experimental evolution of the luminescent signal with particle size at room temperature can be better reproduced by assuming the deep hole to be localized near the surface of the nanoparticles. However, the experimental behavior of the intensity and the decay time of the signal with temperature can be rationalized in terms of holes predominantly trapped near the center of the nanoparticles at low temperatures being transferred to surface defects at room temperature. Furthermore, the calculated values of the radiative lifetimes are comparable to the experimental values of the decay time of the visible emission signal. We also study the visible emission band as a function of the number of electrons in the conduction band of the nanoparticle, finding a pronounced dependence of the radiative lifetime but a weak dependence of the energetic position of the maximum intensity.

Afterglow based detection and dosimetry of beta particle irradiated ZrO2.

In this work, we report on the afterglow (AG) response characterization of commercially available ZrO2. Pellet shaped samples previously annealed in air at 1000°C during 24h were exposed to beta particle irradiation in the dose range from 0.5 up to 128Gy and their AG decay curves recorded during 600s after irradiation exposure. The characteristic glow curves of beta particle irradiated ZrO2 show two maxima located around 80°C and 150°C. The first one rapidly vanishes at room temperature, giving rise to AG. The integrated AG signal increases as dose increases from 0.5 to 128Gy, with a linear dependence from 0.5 up to ca. 32Gy. Excellent reproducibility of the AG response was observed in 10 irradiation - AG readout cycles, showing that the studied ZrO2 samples are reusable. The results here presented show that ZrO2 is a promising material for use as a radiation dosimeter based on the AG phenomenon.

Afterglow dosimetry performance of beta particle irradiated lithium zirconate.

In this work, we report for the very first time on the thermoluminescence (TL) and afterglow (AG) properties of Li2ZrO3. The ternary oxide Li2ZrO3 was synthesized by solid state reaction of a mixture of Li2CO3 and ZrO2 subjected to thermal annealing at 400°C for 2h and 1000°C during 24h in air. The characteristic glow curves of beta particle irradiated samples exhibit an intense TL emission located around 150°C. From the shape of the TL curve, a 0.4 form factor was determined, suggesting that first order kinetics processes are involved. The afterglow decay curves were recorded after exposure to beta particle irradiation in the dose range from 0.5 up to 2kGy. The AG integrated in the time interval from 510 to 600s after radiation exposure shows a linear dependence as a function of the irradiation dose from 0.5 up to 256Gy. A method is proposed to compute the lower detection limit and the AG sensitivity and applied to the studied phosphors. Structural and morphological characterization were carried out by X-ray diffraction and Scanning Electron Microscopy, respectively. From the results presented, it is concluded that the AG response of the synthesized Li2ZrO3 presents features suitable to develop radiation detectors and dosimeters.

Infrared Absorption and Hot Electron Production in Low-Electron-Density Nanospheres: A Look at Real Systems.

Doped semiconductor quantum dots are a new class of plasmonic systems exhibiting infrared resonances. At ultralow concentrations of charge carriers that can be achieved by controlled doping, only few carriers occupy each quantum dot; therefore, a spectrum with well-defined atomic-like peaks is expected. Here we investigate theoretically how surface imperfections and inhomogeneities in shape and morphology (surface "roughness") always present in these nanocrystals, randomize their energy levels, and blur the atomic-like features. We assume a Gaussian distribution of each energy level and use their standard deviation σ as a measure of the nanocrystals' roughness. For nearly perfect nanospheres with small roughness (σ), the spectrum exhibits well-defined peaks. However, increasing roughness effectively randomizes the energy level distribution, and when σ approaches 15% of the nanoparticle's Fermi energy, any trace of an atomic-like structure is lost in the spectrum, and a continuous yet few-conduction-electron localized surface plasmon resonance emerges.

Diffuse Surface Scattering in the Plasmonic Resonances of Ultralow Electron Density Nanospheres.

Localized surface plasmon resonances (LSPRs) have recently been identified in extremely diluted electron systems obtained by doping semiconductor quantum dots. Here, we investigate the role that different surface effects, namely, electronic spill-out and diffuse surface scattering, play in the optical properties of these ultralow electron density nanosystems. Diffuse scattering originates from imperfections or roughness at a microscopic scale on the surface. Using an electromagnetic theory that describes this mechanism in conjunction with a dielectric function including the quantum size effect, we find that the LSPRs show an oscillatory behavior in both position and width for large particles and a strong blue shift in energy and an increased width for smaller radii, consistent with recent experimental results for photodoped ZnO nanocrystals. We thus show that the commonly ignored process of diffuse surface scattering is a more important mechanism affecting the plasmonic properties of ultralow electron density nanoparticles than the spill-out effect.

Surface scattering contribution to the plasmon width in embedded Ag nanospheres.

Nanometer-sized metal particles exhibit broadening of the localized surface plasmon resonance (LSPR) in comparison to its value predicted by the classical Mie theory. Using our model for the LSPR dependence on non-local surface screening and size quantization, we quantitatively relate the observed plasmon width to the nanoparticle radius R and the permittivity of the surrounding medium ε(m). For Ag nanospheres larger than 8 nm only the non-local dynamical effects occurring at the surface are important and, up to a diameter of 25 nm, dominate over the bulk scattering mechanism. Qualitatively, the LSPR width is inversely proportional to the particle size and has a nonmonotonic dependence on the permittivity of the host medium, exhibiting for Ag a maximum at ε(m) ≈ 2.5. Our calculated LSPR width is compared with recent experimental data.

Quasi-resonant neutralization of He+ ions at a germanium surface.

When low-energy He ions are scattered from a Ge surface, the fraction of positive ions exhibits characteristic oscillations as a function of ion energy. These oscillations are caused by quasi-resonant neutralization (qRN), a process which is active for materials with a narrow band nearly resonant with the unperturbed He 1s-level. In this paper we measure the fraction of He+ backscattered from Ge(100). In conjunction with recently developed theoretical methods, we extract quantitative information on the efficiency of qRN. Our evaluation reveals that qRN is a highly efficient process leading to ion fractions two orders of magnitude lower than in systems for which neutralization is only due to Auger processes.

Effects of the atomic level shift in the Auger neutralization rates of noble metal surfaces.

In this work we compare characteristics of Auger neutralization of [Formula: see text] ions at noble metal and free-electron metal surfaces. For noble metals, we find that the position of the energy level of He with respect to the Fermi level has a non-negligible influence on the values of the calculated Auger rates through the evaluation of the surface dielectric susceptibility. We conclude that even though our calculated rates are accurate, further theoretical effort is needed to obtain realistic values of the energy level of He in front of these surfaces.

Role of d electrons in Auger neutralization at metal surfaces.

A generalized theory of Auger electron transfer processes in the interaction of ions with metal surfaces, including the previously ignored role of d electrons is presented. It is shown that a correct and accurate description of Auger neutralization has to account for the contribution of d electrons, as this is illustrated on the case of He+ ion neutralization on Ag, where the neglect of these leads to a strong overestimation of ion survival probabilities. Crystal lattice site specific rates are calculated and allow for a correct description of crystal azimuthal effects in neutralization.

Surface miller index dependence of Auger neutralization of ions on surfaces.

Neutralization of He+ ions in grazing incidence scattering on Ag(111) and Ag(110) surfaces is studied. These measurements reveal the existence of an order of magnitude difference in the probability of ion survival on Ag(110) and Ag(111). The experimental results are discussed in terms of survival from Auger neutralization, whose rates are derived theoretically. Molecular dynamics simulation of scattered ion trajectories is performed and the surviving ion fractions are then calculated using the theoretical Auger neutralization rates, without adjustable parameters. The calculations agree quite well with the experimental data and show that the observed differences in the neutralization probabilities on these surfaces are related to different extensions of the electron density beyond the surface, resulting from different atomic packing.

Osteopetrosis: hallazgos mediante resonancia magnética craneal / Osteopetrosis: findings on cranial magnetic resonance

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Resonancia magnética en el cerebro hendido bilateral asociado a quiste subaracnoideo / Magnetic resonance in bilateral brain associated with a subarachnoid cyst

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