Optimized Route for the Fabrication of MnAlC Permanent Magnets by Arc Melting.

The rare-earth-free MnAlC alloy is currently considered a very promising candidate for permanent magnet applications due to its high anisotropy field and relatively high saturation magnetization and Curie temperature, besides being a low-cost material. In this work, we presented a simple fabrication route that allows for obtaining a magnetically enhanced bulk τ-MnAlC magnet. In the fabrication process, an electric arc-melting method was carried out to melt ingots of MnAlC alloys. A two-step solution treatment at 1200 °C and 1100 °C allowed us to synthesize a pure room-temperature ε-MnAlC ingot that completely transformed into τ-MnAlC alloy, free of secondary phases, after an annealing treatment at 550 °C for 30 min. The Rietveld refinements and magnetization measurements demonstrated that the quenched process produces a phase-segregated ε-MnAlC alloy that is formed by two types of ε-phases due to local fluctuation of the Mn. Room-temperature hysteresis loops showed that our improved τ-MnAlC alloy exhibited a remanent magnetization of 42 Am2/kg, a coercive field of 0.2 T and a maximum energy product, (BH)max, of 6.07 kJ/m3, which is higher than those reported in previous works using a similar preparation route. Experimental evidence demonstrated that the synthesis of a pure room-temperature ε-MnAlC played an important role in the suppression of undesirable phases that deteriorate the permanent magnet properties of the τ-MnAlC. Finally, magnetic images recorded by Lorentz microscopy allowed us to observe the microstructure and magnetic domain walls of the optimized τ-MnAlC. The presence of magnetic contrasts in all the observed grains allowed us to confirm the high-quality ferromagnetic behavior of the system.

Prevalencia de aspergilosis broncopulmonar alérgica en niños con fibrosis quística / Prevalence of bronchopulmonary aspergillosis in children with cystic fibrosis

La aspergilosis broncopulmonar alérgica (ABPA) es una reacción de hipersensibilidad secundaria al Aspergillus fumigatus (Af) que complica la evolución en fibrosis quística (FQ). Existen pocos estudios pediátricos de su prevalencia publicados en el mundo y en Chile se desconoce. El objetivo de este trabajo fue estimar la prevalencia de ABPA en niños con FQ en un hospital de referencia, explorar factores de riesgo y describir los criterios diagnósticos, tratamiento y evolución. Se incluyeron retrospectivamente los niños con FQ atendidos en un hospital terciario en Santiago de Chile (Hospital Roberto del Río) entre los años 2011 a 2019, se identificaron aquellos con diagnóstico de ABPA. Se registraron criterios diagnósticos según la Cystic Fibrosis Foundation, presencia de factores de riesgo, tratamientos recibidos y efectos adversos. De 65 pacientes con FQ atendidos en este período, la prevalencia de ABPA fue del 12%. El promedio de edad al diagnóstico fue ± 11 años (5-17 años), predominando la edad adolescente y el género masculino. El 50% cumplieron con los criterios clásicos, el 87,5% usaron antibióticos y el 62,5% corticoides inhalados. La respuesta favorable al tratamiento inicial con corticoides y antifúngico vía oral fue 62,5%, con una exacerbación al momento del estudio. El 25% se comportaron como refractario y el 12,5% respondieron a tratamiento con pulsos de metilprednisolona. El 37,5% presentaron eventos adversos relacionados a corticoides. La prevalencia de ABPA observada es comparable a las series publicadas. Se necesitan trabajos prospectivos para conocer la prevalencia nacional y su tendencia a lo largo de los años, identificando factores de riesgo.

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity response to Aspergillus fumigatus (Af) and worsens outcome in children with cystic fibrosis (CF). Its prevalence varies in the literature, but we do not know it in Chile. The aim of the study was to know the prevalence of ABPA in children with CF and to describe risk factors, diagnostic criteria, treatment and outcome. We included all patients with CF seen in a tertiary hospital in Santiago, Chile (Hospital Roberto del Río), between 2011 and 2019; ABPA cases (CF Foundation diagnostic criteria) were identified for the estimation of the prevalence. Risk factors, diagnostic criteria and treatment were recorded, as proposed by the Cystic Fibrosis Foundation. A total of 65 patients with CF were identified in the study period, with a prevalence of 12% (8 cases). Mean age at diagnosis ± 11 years (5-17), more frequent in adolescence and male. CF Foundation criteria diagnostic were identified in 50% of cases, with high frequency of antibiotic use (87,5%) and inhaled steroids (62,5%). Positive oral steroids and antifungal treatment response was 62,5%. Refractary response was 25% and 12,5% needed intravenous metilprednisolone pulses. A 37,5% of cases presented adverse effects to steroids. Prevalence of ABPA is comparable to literature. A prospective study is needed to identified national prevalence and trends, identifying risks factors.

A Low-Cost Tracking System for Running Race Applications Based on Bluetooth Low Energy Technology.

Timing points used in running races and other competition events are generally based on radio-frequency identification (RFID) technology. Athletes' times are calculated via passive RFID tags and reader kits. Specifically, the reader infrastructure needed is complex and requires the deployment of a mat or ramps which hide the receiver antennae under them. Moreover, with the employed tags, it is not possible to transmit additional and dynamic information such as pulse or oximetry monitoring, alarms, etc. In this paper we present a system based on two low complex schemes allowed in Bluetooth Low Energy (BLE): the non-connectable undirected advertisement process and a modified version of scannable undirected advertisement process using the new capabilities present in Bluetooth 5. After fully describing the system architecture, which allows full real-time position monitoring of the runners using mobile phones on the organizer side and BLE sensors on the participants' side, we derive the mobility patterns of runners and capacity requirements, which are determinant for evaluating the performance of the proposed system. They have been obtained from the analysis of the real data measured in the last Barcelona Marathon. By means of simulations, we demonstrate that, even under disadvantageous conditions (50% error ratio), both schemes perform reliably and are able to detect the 100% of the participants in all the cases. The cell coverage of the system needs to be adjusted when non-connectable process is considered. Nevertheless, through simulation and experimental, we show that the proposed scheme based on the new events available in Bluetooth 5 is clearly the best implementation alternative for all the cases, no matter the coverage area and the runner speed. The proposal widely exceeds the detection requirements of the real scenario, surpassing the measured peaks of 20 sensors per second incoming in the coverage area, moving at speeds that range from 1.5 m/s to 6.25 m/s. The designed real test-bed shows that the scheme is able to detect 72 sensors below 600 ms, fulfilling comfortably the requirements determined for the intended application. The main disadvantage of this system would be that the sensors are active, but we have proved that its consumption can be so low (9.5 µA) that, with a typical button cell, the sensor battery life would be over 10,000 h of use.

Proposal and Evaluation of BLE Discovery Process Based on New Features of Bluetooth 5.0.

The device discovery process is one of the most crucial aspects in real deployments of sensor networks. Recently, several works have analyzed the topic of Bluetooth Low Energy (BLE) device discovery through analytical or simulation models limited to version 4.x. Non-connectable and non-scannable undirected advertising has been shown to be a reliable alternative for discovering a high number of devices in a relatively short time period. However, new features of Bluetooth 5.0 allow us to define a variant on the device discovery process, based on BLE scannable undirected advertising events, which results in higher discovering capacities and also lower power consumption. In order to characterize this new device discovery process, we experimentally model the real device behavior of BLE scannable undirected advertising events. Non-detection packet probability, discovery probability, and discovery latency for a varying number of devices and parameters are compared by simulations and experimental measurements. We demonstrate that our proposal outperforms previous works, diminishing the discovery time and increasing the potential user device density. A mathematical model is also developed in order to easily obtain a measure of the potential capacity in high density scenarios.

Analytical and Experimental Performance Evaluation of BLE Neighbor Discovery Process Including Non-Idealities of Real Chipsets.

The purpose of this paper is to evaluate from a real perspective the performance of Bluetooth Low Energy (BLE) as a technology that enables fast and reliable discovery of a large number of users/devices in a short period of time. The BLE standard specifies a wide range of configurable parameter values that determine the discovery process and need to be set according to the particular application requirements. Many previous works have been addressed to investigate the discovery process through analytical and simulation models, according to the ideal specification of the standard. However, measurements show that additional scanning gaps appear in the scanning process, which reduce the discovery capabilities. These gaps have been identified in all of the analyzed devices and respond to both regular patterns and variable events associated with the decoding process. We have demonstrated that these non-idealities, which are not taken into account in other studies, have a severe impact on the discovery process performance. Extensive performance evaluation for a varying number of devices and feasible parameter combinations has been done by comparing simulations and experimental measurements. This work also includes a simple mathematical model that closely matches both the standard implementation and the different chipset peculiarities for any possible parameter value specified in the standard and for any number of simultaneous advertising devices under scanner coverage.

Tormenta tiroidea: una urgencia endocrinológica / Thyroid storm: an endocrinological urgency

Thyroid storm is a rare and potentially fatal disease characterized by severe clinical manifestations of thyrotoxicosis. The most common cause of hyperthyroidism is Graves's disease (GD) and infections are the most important precipitating factor. A woman of 33 years with history of hyperthyroidism, hypertension and morbid obesity. She was treated with propylthiouracil for one year, and then suspended controls and treatment 2 years ago. Consult for 2 weeks characterized by dyspnea, cough and expectoration, plus an episode of generalized tonic-clonic seizure. In postictal state, persists with dyspnea and chest pain, which is brought to the emergency room. It is hypotensive, with fever and tachycardia, SatO2 60% on room air. It is intubated and connected to invasive mechanical ventilation. It evolves with monomorphic ventricular tachycardia, requiring cardioversion twice, recovering sinus rhythm. Imaging studies reported bilateral lung disease. CT scan brain and lumbar punture are normal. As is treated as septic shock lung focus. Among its tests: TSH 0.01 mIU/L, T4 T 23.9 ug/dL, T4L 4.77 ng/dL, T3 5.38 ng/ml, with Wartofsky Score: 90. It is managed as TS, treatment is initiated with methimazole, Propranolol, Hydrocortisone. Thyroid ultrasound shows: Goiter with cold nodules. In addition has positive TRAb. She recovers both of system cardiovascular and their respiratory infection. The patient is prepared with amiodarone and lugol for total thyroidectomy. Concordant biopsy with GD.

Provisioning vehicular services and communications based on a bluetooth sensor network deployment.

It is very common to rule out Bluetooth as a suitable technology for vehicular communications. The reasons behind this decision usually result from misconceptions such as accepting that Bluetooth has a short application range, or assuming its connection setup is not fast enough to allow communication which involves high speed moving nodes. This paper refutes those assertions and proposes the use of Bluetooth not only for Infrastructure-to-Vehicle (I2V) or Road-to-Vehicle (R2V) communications, but also for Vehicle-to-Vehicle (V2V) or Vehicle-to-Infrastructure (V2I) communications. This novel proposal is based on using the remote name request procedure of the standard, combined with an adjustment and optimization of the parameters present in the inquiry and page procedures. The proposed modifications reduce the information exchange delay, thus making Bluetooth a suitable technology for high-speed vehicle communications. The feasibility of the proposed scheme has been validated through experimental tests conducted in different scenarios: laboratory, a real highway and a racing test circuit. There, the communication system was installed in a vehicle circulating at speeds of up to 250 km/h, whereas autonomous devices were disseminated throughout the road path to communicate with the on board devices obtaining satisfying results.

[Prolonged hypothermia in refractory intracranial hypertension. Report of one case]. / Hipotermia intravascular prolongada en un paciente con hipertensión endocraneana refractaria.

The use of hypothermia after cardiac arrest caused by ventricular fibrillation is a standard clinical practice, however its use for neuroprotection has been extended to other conditions. We report a 23-year-old male with intracranial hypertension secondary to a parenchymal hematoma associated to acute hydrocephalus. An arterial malformation was found and embolized. Due to persistent intracranial hypertension, moderate hypothermia with a target temperature of 33°C was started. After 12 hours of hypothermia, intracranial pressure was controlled. After 13 days of hypothermia a definitive control of intracranial pressure was achieved. The patient was discharged 40 days after admission, remains with a mild hemiparesia and is reassuming his university studies.

Hipotermia intravascular prolongada en un paciente con hipertensión endocraneana refractaria / Prolonged hypothermia in refractory intracranial hypertension. Report of one case

The use of hypothermia after cardiac arrest caused by ventricular fibrillation is a standard clinical practice, however its use for neuroprotection has been extended to other conditions. We report a 23-year-old male with intracranial hypertension secondary to a parenchymal hematoma associated to acute hydrocephalus. An arterial malformation was found and embolized. Due to persistent intracranial hypertension, moderate hypothermia with a target temperature of 33°C was started. After 12 hours of hypothermia, intracranial pressure was controlled. After 13 days of hypothermia a definitive control of intracranial pressure was achieved. The patient was discharged 40 days after admission, remains with a mild hemiparesia and is reassuming his university studies.