Feed-forward Space Vector Modulation for Single-Phase Multilevel Cascade Converters with any DC voltage ratio

Modulation techniques for multilevel converters can create distorted output voltages and currents if the DC link voltages are unbalanced. This situation can be avoided if the instantaneous DC voltage error is not taken into account in the modulation process. This paper proposes a feed-forward space vector modulation method for a single-phase multilevel cascade converter. Using this modulation technique, the modulated output voltage of the power converter always generates the reference determined by the controller even in worst case voltage unbalance conditions. In addition the possibility of optimizing the DC voltage ratio between the H-bridges of the power converter is introduced. Experimental results from a 5kVA prototype are presented in order to validate the proposed modulation technique

Simultaneous time-space resolved reflectivity and interferometric measurements of dielectrics excited with femtosecond laser pulses

13 pags., 7 figs., 1 tab.Simultaneous time-and-space resolved reflectivity and interferometric measurements over a temporal span of 300 ps have been performed in fused silica and sapphire samples excited with 800 nm, 120 fs laser pulses at energies slightly and well above the ablation threshold. The experimental results have been simulated in the frame of a multiple-rate equation model including light propagation. The comparison of the temporal evolution of the reflectivity and the interferometric measurements at 400 nm clearly shows that the two techniques interrogate different material volumes during the course of the process. While the former is sensitive to the evolution of the plasma density in a very thin ablating layer at the surface, the second yields an averaged plasma density over a larger volume. It is shown that self-trapped excitons do not appreciably contribute to carrier relaxation in fused silica at fluences above the ablation threshold, most likely due to Coulomb screening effects at large excited carrier densities. For both materials, at fluences well above the ablation threshold, the maximum measured plasma reflectivity shows a saturation behavior consistent with a scattering rate proportional to the plasma density in this fluence regime. Moreover, for both materials and for pulse energies above the ablation threshold and delays in the few tens of picoseconds range, a simultaneous >low reflectivity> and >low transmission> behavior is observed. Although this behavior has been identified in the past as a signature of femtosecond laser-induced ablation, its origin is alternatively discussed in terms of the optical properties of a material undergoing strong isochoric heating, before having time to substantially expand or exchange energy with the surrounding media.This work has been partly funded by Laserlab-Europe (Grant Agreement No. 284464, EU’s Seventh Framework Programme, Project No. SLIC002014), by the Spanish Ministry of Economy and Competiveness (Project No. TEC2014-52642- C2-1-R) as well as by the Danish Council for Independent Research | Natural Sciences. M.G.-L. acknowledges the FPU (Formación de Profesorado Universitario) Grant No. AP2012- 0217 awarded by the Spanish Ministry of Education.Peer Reviewe

Hormony tarczycy i otyłość: znana, lecz słabo rozpoznana relacja

Hormony tarczycy (thyroid hormones, TH) są zaangażowane w wiele różnych procesów biologicznych, wliczając rozwój układu nerwowego, regulację metabolizmu pośredniego oraz zużycie energii. Aktywnie uczestniczą w podstawowym zużyciu energii i termogenezie adaptacyjnej i z tego względu mogą mieć wpływ na masę ciała w przebiegu chorób tarczycy. Otyłość to niezakaźna, przewlekła, zapalna choroba metaboliczna, która implikuje dodatni bilans energetyczny. Tkanka tłuszczowa produkuje szereg hormonów i adipocytokin, takich jak leptyna, które mogą wpływać na stan tarczycy na różnych poziomach. Istnieją dowody na to, że dysfunkcja tarczycy może predysponować do otyłości i odwrotnie, istnieją dowody sugerujące, że otyłość powoduje zmiany dotyczące tarczycy. Celem tej pracy było opisanie związku między układem tarczycy a otyłością. Ponadto w pracy zaprezentowano hipotetyczny model podkreślający znaczenie obwodowej dejodynacji hormonów tarczycy i jego rolę w ustanowieniu dodatniego bilansu energetycznego. Podsumowując, możemy stwierdzić, że relacja między układem tarczycy a otyłością i nadwagą jest złożona i obejmuje wiele poziomów interakcji. Ponadto, poddając ocenie otyłego pacjenta, powinno się rozważyć ocenę funkcji tarczycy, aby uzyskać lepsze i spersonalizowane efekty leczenia

Model predictive control with constant switching frequency using a discrete space vector modulation with virtual state vectors

Finite states model predictive control (FS-MPC) appears as a promising control technique to be applied to power converters in the industry. However, the FS-MPC presents some drawbacks as non constant switching frequency and high sampling frequency. This work proposes a FS-MPC with constant switching frequency and low sampling frequency applying a discrete space vector modulation (DSVM) technique. The real state vectors of the converter are used together with new virtual state vectors forming switching sequences each sampling period. The advantages and disadvantages of the proposed FS-MPC with the DSVM are analysed using a two-level three-phase inverter connected to the grid as setup to introduce the proposed technique. Simulation results are presented, showing that using the proposed technique the switching frequency is fixed and the sampling frequency can be lowered without reducing the quality of the converter behaviour

Consensus of experts from the Spanish pharmacogenetics and pharmacogenomics society and the Spanish society of medical oncology for the genotyping of DPYD in cancer patients who are candidates for treatment with fluoropyrimidines

5-Fluorouracil (5-FU) and oral fluoropyrimidines, such as capecitabine, are widely used in the treatment of cancer, especially gastrointestinal tumors and breast cancer, but their administration can produce serious and even lethal toxicity. This toxicity is often related to the partial or complete deficiency of the dihydropyrimidine dehydrogenase (DPD) enzyme, which causes a reduction in clearance and a longer half-life of 5-FU. It is advisable to determine if a DPD deficiency exists before administering these drugs by genotyping DPYD gene polymorphisms. The objective of this consensus of experts, in which representatives from the Spanish Pharmacogenetics and Pharmacogenomics Society and the Spanish Society of Medical Oncology participated, is to establish clear recommendations for the implementation of genotype and/or phenotype testing for DPD deficiency in patients who are candidates to receive fluoropyrimidines. The genotyping of DPYD previous to treatment classifies individuals as normal, intermediate, or poor metabolizers. Normal metabolizers do not require changes in the initial dose, intermediate metabolizers should start treatment with fluoropyrimidines at doses reduced to 50%, and poor metabolizers are contraindicated for fluoropyrimidinesThis project has been financed with SEOM and SEFF resource

1,3,5-Triazines with aromatic amino acids: Exploring their potential as lectin mimetics

VII Escuela de verano de la SEQT, Sociedad Española de Química Terapeútica, Barcelona, 19-21 Julio, 202

Pérdida de dientes en adolescentes y adultos jóvenes universitarios mexicanos

una población universitaria de adolescentes y adultos jóvenes, así como conocer su distribución por edad y sexo. Se realizó un estudio transversal en una muestra de 1027 adolescentes y adultos jóvenes de 16 a 25 años de edad seleccionados aleatoriamente del total de aspirantes a las licenciaturas de la Universidad Autónoma de San Luis Potosí, México. La variable dependiente fue la prevalencia de PD, codificándose como 0=sujetos sin PD y 1=sujetos que tuvieron almenos un diente perdido. Otras variables incluidas fueron edad y sexo del sujeto. El análisis se llevó a cabo en STATA v9,0 con regresión logística. El promedio de edad de los sujetos incluidos fue de 18,20±1,65 y 52,0% fueron hombres. La prevalencia de sujetos con PD fue de 18,0% (n=185) y el promedio de 0,46±1,13, mientras que en quienes tuvieron al menos uno perdido fue de 2,54±1,32. El número máximo de PD fue de 5. En el modelo ajustado obtuvimos significancia estadística en la edad (RM=1,11; p<0,05). Las mujeres tuvieron 41% mayor riesgo de presentar al menos un diente perdido que los hombres. Los sujetos que presentaron más de 6 obturacionestuvieron mayor posibilidad de tener dientes perdidos (RM=1,60; p<0,05). Los hallazgos indican que la experiencia de tener PD alcanza casi el 20%, además se mostró una asociación entre la PD con la edad, el sexo y el número de obturaciones. Este estudio demuestra la existencia de desigualdades de género

Dental caries’ experience, prevalence and severity in mexican adolescents

Objective Determining dental caries’ experience, prevalence and severity in students applying for degree courses at San Luis Potosi University (UASLP). Material and Methods A cross-sectional study was carried out involving adolescents and young adults (16 to 25 years old) applying for undergraduate courses at UASLP (~10 %, n=1 027). Two standardized examiners undertook dental examinations; DMFT index, prevalence (DMFT and gt;0), severity (DMFT and gt;3 and DMFT and gt;6) and significant caries index (SiC) were calculated. STATA 9.0 non-parametric tests were used for statistical analysis.Results Mean age was 18.20±1.65; 48.0% were female. The DMFT index was 4.04±3.90 and caries prevalence was 74.4%. Regarding caries’ severity, 48.8% had MDFT and gt;3 and 24% DMFT and gt;6. The SiC index was 8.64. Females had higher caries experience than males (4.32±4.01 cf 3.78±3.78; p0.05). Age was associated with both experience (

The Enzymatic Activity of Type 1 Iodothyronine Deiodinase (D1) is Low in Liver Hemangioma: A Preliminary Study

Type 1 iodothyronine deiodinase (D1) is a crucial enzyme which converts the prohormone thyroxine (T4) into active tri-iodothyronine (T3). There has been strong evidence that the metabolism of thyroid hormones is disturbed in some neoplastic tissues such as thyroid, renal, and breast cancer. However, there are few available data about D1 enzyme activity in benign tumors such as hemangioma, which is the most common primary liver tumor. Hence this study aimed to determine the enzymatic activity of D1 in hemangiomas in relation to healthy liver tissue. Seven tumors and healthy control tissues were obtained from patients who had liver resection due to hemangioma. The activity was assessed by measurement of radioactive iodine released by deiodination catalyzed by D1. It was found that D1 activity was significantly lower in the hemagiomas than in the healthy surrounding tissue (p = 0.0017). The results indicated that thyroid hormones play important roles not only in the regulation of cell metabolism, but also in cell growth, division, and apoptosis. The active form T3 acts through its nuclear receptors and influences the up- and down-regulation of target genes. Healthy liver tissue expresses a high level of D1, but disturbed D1 activity may result in changes in the local concentration of T3 which may impair gene transcription. These finding demonstrate a low enzymatic activity of D1 in liver hemangioma and suggest an as yet unknown role of thyroid hormones in this type of benign liver tumor