205 research outputs found
Efficiency enhancement by reconfigurable matching networks in LINC transmitters
This paper proposes the use of a transmitter based on a linear amplification with nonlinear components (LINC) architecture, in which the reconfigurable matching networks (RMNs) are included. By varying the RMN active cell number, it is possible to change the load impedance at the power amplifier (PA) output, improving the amplifier drain efficiency and therefore the efficiency of the whole system. A long-term evolution (LTE) downlink signal with a bandwidth of 1.4 MHz and a peak-to-average power ratio (PAPR) of 11.48 dB is applied in order to carry out the experiments. Results show that the use of the RMNs in a LINC architecture improves the efficiency at all tested frequencies, especially at 927 MHz reaching an enhancement of 36.50%. Regarding the distortion, the adjacent channel leakage ratio (ACLR) values increase in all cases, with an improvement of 3.5 dB at 958 MHz. Finally, in terms of error vector magnitude (EVM), the proposed architecture offers a value of 1.96% at 927 MHz
Aportación al conocimiento del género Cheilanthes en la Península Ibérica
Cheilanthes pulchella and Cheilanthes x insularis are mentionedas new from the Iberian Peninsula and distribution of Cheilanthes guanchica and Cheilanthes x iberica is amplied. The Cheilanthes taxa from the Iberian Peninsuli are listed. Key of determination is proposed.En esta nota se citan por primera vez en la Península Ibérica Cheilanthes pulcheIla y Cheilanthes x insularis y se amplia la distribución de Cheilanthes guanchica y Cheilanthes x iberica. Se completa el catálogo de los táxones de este género en la Península Ibérica, añadiéndose una clave de determinación para los mismos
Identification of two novel mutations in CDHR1 in consanguineous Spanish families with autosomal recessive retinal dystrophy.
Inherited retinal dystrophies present extensive phenotypic and genetic heterogeneity, posing a challenge for patients' molecular and clinical diagnoses. In this study, we wanted to clinically characterize and investigate the molecular etiology of an atypical form of autosomal recessive retinal dystrophy in two consanguineous Spanish families. Affected members of the respective families exhibited an array of clinical features including reduced visual acuity, photophobia, defective color vision, reduced or absent ERG responses, macular atrophy and pigmentary deposits in the peripheral retina. Genetic investigation included autozygosity mapping coupled with exome sequencing in the first family, whereas autozygome-guided candidate gene screening was performed by means of Sanger DNA sequencing in the second family. Our approach revealed nucleotide changes in CDHR1; a homozygous missense variant (c.1720C > G, p.P574A) and a homozygous single base transition (c.1485 + 2T > C) affecting the canonical 5' splice site of intron 13, respectively. Both changes co-segregated with the disease and were absent among cohorts of unrelated control individuals. To date, only five mutations in CDHR1 have been identified, all resulting in premature stop codons leading to mRNA nonsense mediated decay. Our work reports two previously unidentified homozygous mutations in CDHR1 further expanding the mutational spectrum of this gene
Contribución al estudio de las comunidades rupícolas de la Cheilanthetalia marantho-maderensis y Androsacetalia vandellii en la Península Ibérica
An study on the Iberian Peninsula rocks comunities it is going on with dominantes by several species of the genus Cheilaruhes and Notholaena, from these the new associations of the Phagnalo saxatile-Cheilanthion maderensis alliance (Cheilanthetalia maranto-maderensis, Asplenietea trichomanis): Notholaeno marantae-Cheilanthetum guanchicae are proposed the first distinctive of the Bermejense Subsector (Rondefio Sector, Betica chorological Province) and the second Cheilantho maderensis-Cosentinietum velleae with is basically of the Betic distribution. Based on the bibliography and on our own data, a comparative analysis of the casmofitic comunities on the Cheilanthetalia maranto-maderensis order and Androsacetalia vandellii order are presented, taking into account their relationships with Phagnalo-Rumicetea indurati. Forthermore from this last one the association Phalacro- carpoSaxifragetum continent alis is also described.Se lleva a cabo un estudio de las comunidades rupícolas ibéricas presididas por diversas especies de los géneros Cheilanthes y Notholaena, proponiéndose dos nuevas asociaciones de la alianza Phagnalo saxatile-Cheilanthion maderensis (Cheilanthetalia maranto-maderensis, Asplenietea trichomanis): Notholaeno marantae-Cheilanthetum guanchicae, propia del Subsector Bermejense (Sector Ronderlo, Provincia Bética) y Cheilantho maderensis-Cosentinietum velleae, de distribución fundamentalmente bética. Con datos propios y otros bibliográficos, se hace un análisis crítico, a la vez que un estudio comparado, de las comunidades casmofíticas incluidas en los órdenes Cheilanthetalia maranto-maderensis (termomediterránea y silicíbasícola) y Androsacetalia vandellii (montana y supracrioro mediterránea, silicícola), analizando sus relaciones con las comunidades comofíticas de la Phagnalo-Rumicetea indurati. De esta última se describe la asociación Phalacrocarpo-Saxifragetum continentalis (Saxtfragion continentalis)
Linealización mediante Predistorsión Digital de un Sistema Radio sobre Fibra de Doble Banda
En este artículo se propone la linealización de un sistema Radio-over-Fiber (RoF) de doble banda mediante predistorsión digital. Los resultados han sido evaluados experimentalmente con señales LTE en un sistema RoF, obteniendo mejores resultados que con el predistorsionador clásico de una banda en términos de Adjacent Channel Power Ratio (ACPR), pérdidas de potencia y Error Vector Magnitude (EVM).
Phosphodiesterase 7 inhibitor reduced cognitive impairment and pathological hallmarks in a mouse model of Alzheimer's disease
La universidad humanista
Esta obra, titulada La universidad humanista, es fruto de la colaboración entre dos instituciones centenarias: la Universidad de Santiago de Compostela, una de las universidades más antiguas de España que ofrece educación superior desde 1495 y la Universidad Autónoma del Estado de México, heredera del Instituto Científico y Literario Autónomo, fundado en 1828, a escasos siete años de que México naciera como entidad política independiente. Ambas instituciones, con un pasado muy diferente, se encuentran hermanadas por la misma vocación de futuro y las preocupaciones propias de las universidades del siglo XXI.Universidad Autónoma del Estado de México y Universidad de Santiago de Compostel
A 3-portal approach for arthroscopic subtalar arthrodesis
We present a 3-portal approach for arthroscopic subtalar arthrodesis with the patient in the prone position. The prone position allows the use of the two standard posterior portals and it allows for accurate control of hindfoot alignment during surgery. Furthermore, the introduction of talocalcaneal lag screws is easy with the patient in this position. In addition to the standard posterior portals, an accessory third portal is created at the level of the sinus tarsi for introduction of a large diameter blunt trocar to open up the subtalar joint. Due to the curved geometry of the posterior subtalar joint, removal of the anterior articular cartilage is impossible by means of the posterior portals only. An advantage of the 3-portal approach is that ring curettes can be introduced through the accessory sinus tarsi portal to remove the articular cartilage of the anterior part of the posterior talocalcaneal joint. Arthroscopic subtalar arthrodesis in patients with a talocalcaneal coalition presents a technical challenge as the subtalar joint space is limited. The 3-portal technique was successfully used in three subsequent patients with a talocalcaneal coalition; bony union of the subtalar arthrodesis occurred at 6 weeks following surgery. With the 3-portal technique, a safe and time-efficient arthroscopic subtalar arthrodesis can be performed even in cases with limited subtalar joint space such as in symptomatic talocalcaneal coalition
Arthroscopic Treatment of Pediatric Fractures
Management of pediatric articular fractures has evolved over the years with a growing interest in arthroscopic handling. Several factors account for this recent appeal among which are progress in technology with increased availability of diagnostic methods, rise in athletic activities responsible for these fractures, and pediatric orthopaedic surgeons getting familiar with arthroscopic techniques. In our institution, 9 of 100 arthroscopic procedures are performed as a consequence of an articular fracture. In total, 80% of the fractures concern the knee (56% of tibial eminence fracture, 24% osteochondral fracture). Most of the remaining 20% are located at the ankle joint. Given the thorough articular exploration that arthroscopy provides, any associated cartilaginous or meniscal lesions is identified and addressed in the same procedure as the fracture fixation. Being a less invasive surgery with low complication rate, arthroscopic management of pediatric articular fractures provides very satisfactory results with earlier recovery. Of note, it is technically demanding and requires constant training. The operative time should be monitored and alternative options considered for each surgery. In this regard, arthroscopy has to be viewed as a means not an end
Inhibiting the stringent response blocks Mycobacterium tuberculosis entry into quiescence and reduces persistence
The stringent response enables Mycobacterium tuberculosis (Mtb) to shut down its replication and metabolism under various stresses. Here we show that Mtb lacking the stringent response enzyme RelMtb was unable to slow its replication rate during nutrient starvation. Metabolomics analysis revealed that the nutrient-starved relMtb-deficient strain had increased metabolism similar to that of exponentially growing wild-type bacteria in nutrient-rich broth, consistent with an inability to enter quiescence. Deficiency of relMtb increased the susceptibility of mutant bacteria to killing by isoniazid during nutrient starvation and in the lungs of chronically infected mice. We screened a pharmaceutical library of over 2 million compounds for inhibitors of RelMtb and showed that the lead compound X9 was able to directly kill nutrient-starved M. tuberculosis and enhanced the killing activity of isoniazid. Inhibition of RelMtb is a promising approach to target M. tuberculosis persisters, with the potential to shorten the duration of TB treatment.This work was supported by R01AI083125, R21AI122922, and R21AI114507A to P.C.
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