3,991 research outputs found

    Results of a Professional Medical Counseling/surveillance in Preoperative Weight Loss

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    Background:Preoperative weight loss reduces the risk for complications after bariatric surgery.Objectives:To evaluate the effectiveness of a preoperative counseling program compared to general recommendations alone.Setting: Obesity Surgery Unit. Reina Sofia General University Hospital.  Murcia (southeast Spain).Methods: Prospective, randomized controlled study including 162 patients. Participants were randomly assigned to our preoperative intensive behavioral/lifestyle program (Counseling Group:55, 78% women) or to receive general nutritional recommendations (Reference Group:49, 82% women). Primary endpoint was a between-group comparison of percent excess weight loss (%EWL) at 4 months.Results: Counseling Group: baseline Body Mass Index (BMI)1was 45.9±7.3kg/m2 when  enrolled into the education program and reduced to to BMI2:43.2±5.6kg/m2 the day before the operation. After the motivational intervention, we got an average loss of 7.3±3.7kg of body weight and 12.4%EWL in 16 weeks.Reference Group: mean BMI1 was 45.5±7.3kg/m2. The day before surgery, BMI2 was: 46.1±6.1kg/m2. Over a period of 16 weeks the average weight gain was 1.8±1.1kg and -3%EWL (p=0.12). Weight gain was observed in 55% of these patients.The comparison of the mean %EWL in both groups did not reveal any statistically significant differences.  Conclusions: The educational intervention was not statistically significant more effective than general nutritional recommendations in achieving weight loss

    Effectiveness of Telemedicine and Teledentistry after the COVID-19 Pandemic.

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    Telemedicine has become increasingly important worldwide over the last two decades. As a new field, it became known especially during the COVID-19 pandemic; this review presents fields of activity with special attention to opportunities and risks. Numerous areas of application offer the possibility for broad use in the medical and dental care landscape in diagnostics, therapy, rehabilitation, and decision advice across a spatial distance. Technical and semantic standards are required, and profiles and guidelines are increasingly defined and organized. Medical/dental consultations have been established in various regions around the world as a response to pandemic challenges and have made video and online emergency consultations possible. Telemedicine applications are already regularly used in medical/dental emergencies, regardless of the pandemic situation, both for transport by train and by plane, from which patients benefit. However, legal hurdles are often still unresolved, but infrastructure challenges both for provider, user hard- and software also complicate deployment. Problems are particularly prevalent in the absence of necessary internet coverage or among socially disadvantaged and vulnerable groups who cannot afford expensive equipment or do not know how to use the technology. Broad access must be enabled, and hardware and software interfaces and updates must be regularly checked and updated. Telemedicine might also improve access to and delivery of oral and general health care support both for rural and urban areas with low costs. Even though dentistry and many medical specialties are still performed clinically by means of practical/manual examination, there are areas of diagnostics where telemedicine applications can provide good support. Therefore, as conclusions, access, and delivery of telemedicine applications in dentistry and medicine should be expanded and improved to provide access to all population groups

    Phylogenomic analysis of natural products biosynthetic gene clusters allows discovery of arseno-organic metabolites in model streptomycetes

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    We are indebted with Marnix Medema, Paul Straight and Sean Rovito, for useful discussions and critical reading of the manuscript, as well as with Alicia Chagolla and Yolanda Rodriguez of the MS Service of Unidad Irapuato, Cinvestav, and Araceli Fernandez for technical support in high-performance computing. This work was funded by Conacyt Mexico (grants No. 179290 and 177568) and FINNOVA Mexico (grant No. 214716) to FBG. PCM was funded by Conacyt scholarship (No. 28830) and a Cinvestav posdoctoral fellowship. JF and JFK acknowledge funding from the College of Physical Sciences, University of Aberdeen, UK.Peer reviewedPublisher PD

    Amplificador de potencia Clase F en banda L basado en tecnología GaN

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    This paper reports a high efficiency class-F power amplifier based on a gallium nitride high electron mobility transistor (GaN-HEMT), which is designed at the L band of 1640 MHz. The design is based on source and load pull measurements. During the design process, the parasitics of the package of the device are also taken into account in order to achieve the optimal class-F load condition at the intrinsic drain of the transistor. The fabricated class-F power amplifier achieved a maximum drain efficiency (DE) of 77.8% and a output power of 39.6 W on a bandwidth of 280 MHz. Simulation and measurement results have shown good agreement

    Predistorsion Digital Aplicada al Amplificador de Potencia de un Sistema EER

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    A linealized RF power amplifier using Envelope Elimination and Restoration (EER) and predistortion techniques is shown. Measurements on a circuit prototype are presented. The EER system uses a linear regulator to amplify the envelope and a high efficiency broadband VHF class E power amplifier for the phase component. Different digital modulations have been tested in the circuit prototype. Adjacent Channel Power Ratio (ACPR) reaches over 46 dBc for monocarrier modulations and over 34 dBc for multicarrier modulations, for a 2MHz bandwidth on VHF carrier (from 88 MHz to 114 MHz). The system shown provides double efficiency level than an equivalent ideal class A amplifier

    Procedimiento De Amplificador De Envolvente De Señales Moduladas En RF Para Técnicas EER Y ET

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    An envelope amplifier for an EER (Envelope Elimination and Restoration) and ET (Envelope Tracking) techniques is shown in this paper. The amplifier is based on a high speed two phases buck converter and employs RF LDMOS technology for the switching stage. A DPWM (Digital Pulse With Modulation) signal is used to control the amplifier by means of a functions generator. Simulations and measurements on a circuit prototype are presented showing a good agreement. Up to 125W output peak power can be delivered over a 5Ω load resistor. About 80% efficiency has been obtained. And at the two tone test, the third order intermodulation products (IP3) remain below 45dBc over a 2MHz bandwidth

    Amplificador de potencia clase F a 1.64 ghz con control de armónicos

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    This paper presents a high-power high efficiency PA design method using load pull technique. Harmonic impedance control at the virtual drain is accomplished through the use of tunable pre-matching circuits and modeling of package parasitics. A 0.5 µm GaN high electron mobility transistor (HEMT) is characterized using the method, and loadpull measurements are simulated illustrating the impact of varying 2nd and 3rd harmonic termination. These harmonic terminations are added to satisfy conditions for class-F load pull. The method is verified by design and simulation of a 40-W class-F PA prototype at 1.64 GHz with 76% drain efficiency and 10 dB gain (70% PAE)

    Mejora de la Linealidad de un amplificador de Potencia para un Sistema EER Mediante Predistorsion Digital

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    En este trabajo se presenta un amplificador de potencia de RF linealizado mediante la combinaci n de t cnicas de Eliminaci n y Recuperaci n de Envolvente (EER) y Predistorsi n. Se utiliza para ello procesado digital de la se al en banda base y la identificaci n de modelos en el dominio del tiempo para describir el funcionamiento del amplificador de potencia. Empleando m todos basados en la t cnica de error de salida, se calcula e implementa la funci n complementaria no lineal del amplificador de potencia de RF del sistema EER en Matlab, para su posterior linealizaci n. Se han conseguido mejoras de hasta 20 dB usando esta t cnica con respecto a un sistema EER sin linealizar

    Amplificador de envolvente de señales de RF basado en el convertidor buck multifase

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    En este trabajo se presenta un convertidor DC-DC buck de dos fases de alta velocidad adecuado para emplear en técnicas de linealización de amplificadores como ET (Envelope Tracking) o EER (Envelope Elimination and Restoration). El convertidor ha sido realizado con tecnología LDMOS y la técnica usada para controlarlo ha sido modulación PWM, creada mediante procesado digital y un generador de funciones. La potencia de salida es de hasta 125W de pico, con un rendimiento del 80%, un ancho de banda de hasta 2MHz y en las medidas de linealidad presenta una atenuación a los productos de intermodulación de tercer orden de más de 45 dBc
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