88 research outputs found

    Bandwidth-Enhancement gm-C Filter with independent ¿o and Q Tuning Mechanisms in Both Topology and Control Loops

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    This paper deals with the proposal of a new topology for a gm-C continuous time filter which allows the adjustment and tuning of its characteristic parameters (ωO and Q) in an independent way (without cross-tuning), thereby extending the Q range of the filter for a particular ωO value. Additionally a comparison of three different Q-tuning algorithms is presented. It is shown that an LMS-based Q-control strategy allows to overcome the intrinsic dependence between the Q and ωO tuning loops. The combination of both the proposed filter topology and the selected control loop algorithms results in an enhanced transient performance as well as an improvement in terms of cross-detuning.Postprint (published version

    Filtro gm-C para aplicaciones de comunicaciones con sintonía adaptativa del factor de calidad Q independiente de la sintonía de la frecuencia central

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    Este artículo muestra la propuesta de un filtro gm-C de segundo orden con control independiente total de la frecuencia central y el factor de calidad diseñado para aplicaciones inalámbricas multiestándar. Se presenta asimismo el diseño de los lazos de control adecuados para hacer la correcta sintonía del filtro tras una breve descripción de las ventajas e inconvenientes de las propuestas encontradas en la bibliografía. El trabajo se completa con una propuesta de mejora del lazo de control del factor de calidad que permite aumentar la rapidez del lazo y disminuir el error de rizado de la señal de control.Postprint (published version

    Circuito promediador para control de convertidores conmutados de potencia: implemetnación integrada cmos en mod de corriente

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    El presente artículo describe el estudio, la síntesis y la implementación microelectrónica analógica de un método para la obtención del valor medio instantáneo de una señal, en el contexto del control de convertidores conmutados de potencia. Se incluyen tanto una descripción funcional así como las condiciones analíticas que describen la validez del método propuesto. A nivel circuital, la realización de un diseño basado en la aproximación del modo de corriente conlleva un circuito de baja complejidad y elevadas prestaciones dinámicas. Los resultados de simulación para una realización microelectrónica con tecnología CMOS de 0.35 μm muestran un correcto funcionamiento hasta frecuencias de conmutación de 1MHz.Postprint (published version

    Differences in the effects of a startle stimulus on rate of force development between resistance-trained rock climbers and untrained individuals: Evidence for reticulospinal adaptations?

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    The aim of the present cross-sectional study was to determine if chronic rock climbing and climbing-specific resistance training (RT) would modify the reticulospinal tract (RST) efficacy. Sixteen healthy, elite level climbers (CL; n = 16, 5 F; 29.8 ± 6.7 years) with 12 ± 7 years of climbing and climbing-specific RT experience and 15 healthy recreationally active participants (CON; n = 15, 4 F; 24.6 ± 5.9 years), volunteered for the study. We quantified RST efficacy by comparing the effects of a startle stimulus over reaction time (Rtime) and measured rate of force development (RFD) and surface electromyography (sEMG) in representative muscles during powerful hand grip contractions. Both groups performed two Rtime tasks while performing rapid, powerful gripping with the right hand (Task 1) or during 3-s-long maximal voluntary right hand grip contractions in response to an imperative visual signal alone (V), or combined with a auditory-non startle stimulus (A) or/and startling auditory stimulus (S). We also tested the reproducibility of these responses on two separate days in CON. Intersession reliability ranged from 0.34 to 0.96 for all variables. The CL versus CON was 37% stronger (p = 0.003). The S stimulus decreased Rtime and increased RFD and sEMG in both groups during both tasks (all p < 0.001). Rtime was similar between groups in all conditions. However, CL had a greater RFD from 50 to 100 ms compared with CON only after the S stimulus in both tasks (p < 0.05, d = 0.85–0.96). The data tentatively suggest that chronic rock climbing and climbing-specific RT might improve RST efficacy, by increasing RST input to the α-motoneurons13 página

    Metabolic syndrome association with fibrosis development in chronic hepatitis B virus inactive carriers

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    [Abstract] Background and Aim. There are few data of fibrosis development in chronic hepatitis B (CHB) patients classified as inactive carriers. The aim of this study is to determinate the prevalence of significant fibrosis and probable cirrhosis measured by FibroScan in real inactive CHB carriers and investigate the relationship with virological, epidemiological, and metabolic factors. Methods. Cross-sectional cohort study including CHB inactive carriers. Liver stiffness measurement was performed with transient elastography (FibroScan). Significant fibrosis (≥ F2) was defined as stiffness > 7.5 kPa, and probable cirrhosis as > 11.8 kPa. Factors associated with significant fibrosis were explored with univariate and multivariate adjusted logistic regression analyses. Results. Ninety-six CHB inactive carriers were analyzed. Of them, 24 (25%) had significant fibrosis and 7 (7%) probable cirrhosis; mean stiffness was 6.2 ± 2.3 kPa. Of them, 24% had metabolic syndrome, with higher FibroScan value than those without (8.4 kPa vs 5.5 kPa, P < 0.001). Factors associated with significant fibrosis were (odds ratio, 95% confidence interval, P value): central obesity (7.1, 1.8–27.9, 0.005), elevated fasting glucose (4.3, 1.3–27.9, 0.036), reduced high-density lipoprotein cholesterol (5.2, 1.2–23.6, 0.032) and elevated triglycerides (6.2, 1.4–28.3, 0.019). Factors as age, sex, transaminases, hepatitis B virus DNA or genotype were not related with liver fibrosis. The presence of metabolic syndrome has a 69% of positive predictive value and 89% of negative predictive value for significant fibrosis. Conclusion. Different components of metabolic syndrome are associated with fibrosis development in CHB inactive carriers. In the absence of metabolic syndrome, significant fibrosis is uncommon in this population.Instituto de Salud Carlos III; CP08/00214Instituto de Salud Carlos III; PI10/0216

    Diseño e implementación de un filtro MRC-C con sintonía automática on-chip

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    En el presente artículo se describe el diseño e implementación de los lazos de sintonía (tanto del que fija la frecuencia central como del que fija el factor de calidad) de un filtro pasa-banda de tiempo continuo fully-balanced para aplicaciones de audio basado en una modificación de la estructura TQE (Transimpedance Q-Enhacement). El circuito ha sido diseñado y fabricado en tecnología CMOS de 0,8 μm y se han utilizado células del tipo MRC (MOS Resistive Circuit) para poder implementar las resistencias sintonizables electrónicamente. Los resultados experimentales obtenidos para dicha tecnología validan la funcionalidad del circuito de sintonía.Postprint (published version

    Desfasador sintonizable CMOS para aplicaciones de sintonía automática

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    En este artículo se presenta el diseño e implementación de un desfasador con capacidad de sintonía mediante una tensión de control externa, que ofrece un desfase de π/2 a una frecuencia específica de interés. La utilización de resistencias negativas, y su fácil implementación mediante el bloque circuital conocido como MRC (MOS Resistive Circuit) simplifica notablemente el diseño y realización del mismo. Los resultados experimentales obtenidos y expuestos para una tecnología CMOS de 0,8 μm validan la funcionalidad del circuito.Postprint (published version

    Bandwidth-Enhancement gm-C Filter with Independent wo and Q Tuning Mechanisms in Both Topology and Control Loops

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    This paper deals with the proposal of a new topology for a gm-C continuous time filter which allows the adjustment and tuning of its characteristic parameters (ωO and Q) in an independent way (without cross-tuning), thereby extending the Q range of the filter for a particular ωO value. Additionally a comparison of three different Q-tuning algorithms is presented. It is shown that an LMS-based Q-control strategy allows to overcome the intrinsic dependence between the Q and ωO tuning loops. The combination of both the proposed filter topology and the selected control loop algorithms results in an enhanced transient performance as well as an improvement in terms of cross-detuning.Postprint (published version

    Phase 2 Trial (POLA Study) of Lurbinectedin plus Olaparib in Patients with Advanced Solid Tumors: Results of Efficacy, Tolerability, and the Translational Study

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    Endometrial cancer; Genomic instability; OlaparibCáncer endometrial; Inestabilidad genómica; OlaparibCàncer d'endometri; Inestabilitat genòmica; OlaparibWe hypothesized that the combination of olaparib and lurbinectedin maximizes DNA damage, thus increasing its efficacy. The POLA phase 1 trial established the recommended phase 2 dose of lurbinectedin as being 1.5 mg (day 1) and that of olaparib as being 250 mg/12 h (days 1–5) for a 21-day cycle. In phase 2, we explore the efficacy of the combination in terms of clinical response and its correlation with mutations in the HRR genes and the genomic instability (GI) parameters. Results: A total of 73 patients with high-grade ovarian (n = 46), endometrial (n = 26), and triple-negative breast cancer (n = 1) were treated with lurbinectedin and olaparib. Most patients (62%) received ≥3 lines of prior therapy. The overall response rate (ORR) and disease control rate (DCR) were 9.6% and 72.6%, respectively. The median progression-free survival (PFS) was 4.54 months (95% CI 3.0–5.2). Twelve (16.4%) patients were considered long-term responders (LTR), with a median PFS of 13.3 months. No clinical benefit was observed for cases with HRR gene mutation. In ovarian LTRs, although a direct association with GI and a total loss of heterozygosity (LOH) events was observed, the association did not reach statistical significance (p = 0.055). Globally, the total number of LOHs might be associated with the ORR (p =0.074). The most common grade 3–4 toxicities were anemia and thrombocytopenia, in 6 (8.2%) and 3 (4.1%) patients, respectively. Conclusion: The POLA study provides evidence that the administration of lurbinectedin and olaparib is feasible and tolerable, with a DCR of 72.6%. Different GI parameters showed associations with better responses.This trial was sponsored by AstraZeneca and PharmaMar, including supply of the drugs used in this study

    Treatment with tenofovir alafenamide fumarate worsens the lipid profile of HIV‐infected patients versus treatment with tenofovir disoproxil fumarate, each coformulated with elvitegravir, cobicistat, and emtricitabine

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    [Abstract] Two elvitegravir/cobicistat‐based therapies combined with emtricitabine/tenofovir disoproxil fumarate (EVG/c/FTC/TDF) or emtricitabine/tenofovir alafenamide fumarate (EVG/c/FTC/TAF) are currently available for HIV patients. This study evaluated the modifications in the lipid profile of patients who received these treatments in the last three years at our institution. A retrospective observational study in HIV‐infected patients who received EVG/c/FTC/TDF or EVG/c/FTC/TAF from January 2015 to January 2018 at a reference hospital in northwestern Spain was carried out. Epidemiological, clinical and immunovirological data were recorded. A statistical analysis was performed using SPSS software. A total of 384 EVG/c‐based therapies were initiated during the study period, 151 EVG/c/FTC/TDF and 233 EVG/c/FTC/TAF. A significantly negative influence in all the lipid profile parameters in experienced patients and total cholesterol (TC), and LDL‐C in naïve patients were observed after 48 weeks of treatment with EVG/c/FTC/TAF, while these parameters remained stable in the EVG/c/FTC/TDF group. During follow‐up, a greater proportion of patients had lipid levels above the normal range (63.1% TC, 56.2% LDL‐C) and new lipid‐modifying drugs were prescribed (11.9%) in the EVG/c/FTC/TAF group. The number of cardiovascular risk factors (OR 1.66 [95% CI 1.01‐2.72]; P = 0.043) was recognised as an independent predictor of lipid‐lowering prescription for patients treated with both EVG/c/FTC/TDF and EVG/c/FTC/TAF. For patients treated with EVG/c/FTC/TAF, the mean total cholesterol to HDL ratio in the first 48 weeks of the study treatment was associated with a higher likelihood of lipid‐lowering prescription in multivariate analysis (OR 1.6 [95% CI 1.12‐2.52]; P = 0.011). Significant changes in lipid profile have been observed in patients who have received EVG/c/FTC/TAF. It was necessary to prescribe almost twice the number of lipid‐lowering drugs to patients who received EVG/c/FTC/TAF (11.9%) vs EVG/c/FTC/TDF (4.7%)
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