Vanadium oxide and a sharp onset of cold-trapping on a giant exoplanet.

The abundance of refractory elements in giant planets can provide key insights into their formation histories1. Owing to the low temperatures of the Solar System giants, refractory elements condense below the cloud deck, limiting sensing capabilities to only highly volatile elements2. Recently, ultra-hot giant exoplanets have allowed for some refractory elements to be measured, showing abundances broadly consistent with the solar nebula with titanium probably condensed out of the photosphere3,4. Here we report precise abundance constraints of 14 major refractory elements on the ultra-hot giant planet WASP-76b that show distinct deviations from proto-solar and a sharp onset in condensation temperature. In particular, we find nickel to be enriched, a possible sign of the accretion of the core of a differentiated object during the evolution of the planet. Elements with condensation temperatures below 1,550 K otherwise closely match those of the Sun5 before sharply transitioning to being strongly depleted above 1,550 K, which is well explained by nightside cold-trapping. We further unambiguously detect vanadium oxide on WASP-76b, a molecule long suggested to drive atmospheric thermal inversions6, and also observe a global east-west asymmetry7 in its absorption signals. Overall, our findings indicate that giant planets have a mostly stellar-like refractory elemental content and suggest that temperature sequences of hot Jupiter spectra can show abrupt transitions wherein a mineral species is either present or completely absent if a cold trap exists below its condensation temperature8.

Five carbon- and nitrogen-bearing species in a hot giant planet's atmosphere.

The atmospheres of gaseous giant exoplanets orbiting close to their parent stars (hot Jupiters) have been probed for nearly two decades1,2. They allow us to investigate the chemical and physical properties of planetary atmospheres under extreme irradiation conditions3. Previous observations of hot Jupiters as they transit in front of their host stars have revealed the frequent presence of water vapour4 and carbon monoxide5 in their atmospheres; this has been studied in terms of scaled solar composition6 under the usual assumption of chemical equilibrium. Both molecules as well as hydrogen cyanide were found in the atmosphere of HD 209458b5,7,8, a well studied hot Jupiter (with equilibrium temperature around 1,500 kelvin), whereas ammonia was tentatively detected there9 and subsequently refuted10. Here we report observations of HD 209458b that indicate the presence of water (H2O), carbon monoxide (CO), hydrogen cyanide (HCN), methane (CH4), ammonia (NH3) and acetylene (C2H2), with statistical significance of 5.3 to 9.9 standard deviations per molecule. Atmospheric models in radiative and chemical equilibrium that account for the detected species indicate a carbon-rich chemistry with a carbon-to-oxygen ratio close to or greater than 1, higher than the solar value (0.55). According to existing models relating the atmospheric chemistry to planet formation and migration scenarios3,11,12, this would suggest that HD 209458b formed far from its present location and subsequently migrated inwards11,13. Other hot Jupiters may also show a richer chemistry than has been previously found, which would bring into question the frequently made assumption that they have solar-like and oxygen-rich compositions.

Manifestaciones cutáneas en pacientes pediátricos infectados por el coronavirus SARS-CoV-2 / Cutaneous manifestations in pediatric patients infected with SARS-CoV-2 coronavirus

Introducción: El nuevo coronavirus SARS-CoV-2 ha causado un brote grave de la enfermedad denominado COVID-19. El virus fue identificado por primera vez en Wuhan, China, en diciembre del 2019. Recientemente se describieron las manifestaciones cutáneas, con similitud clínica entre niños y adultos. Se identificaron cinco patrones cutáneos: erupción máculo-papular, urticaria, lesiones acrales tipo perniciosas, erupción vesicular y livedo reticularis. Objetivo: Caracterizar a pacientes pediátricos con manifestaciones cutáneas en el curso de la COVID-19. Presentacion de casos: Se estudiaron 10 pacientes pediátricos con COVID-19 ingresados en el Hospital Militar de Villa Clara Comandante Manuel Piti Fajardo. Del total de pacientes, 8 presentaron rash eritemato-papuloso y 2 rash urticariforme. Las lesiones urticariformes se presentaron solamente en las féminas y las eritemato-papulosas, de forma similar en ambos sexos con ligero predominio en las adolescentes pacientes femeninas. Ambas lesiones predominaron en el tronco y acompañadas de un prurito ligero o ausente. Solo requirieron tratamiento médico las lesiones urticariformes. Conclusiones: La principal expresión clínica en la población pediátrica atendida en Villa Clara son las manifestaciones cutáneas. Las lesiones eritemato-papulosas son las más frecuentes, tienen. aparición tardía y evolución favorable sin necesidad de tratamiento y sin acompañarse de otra sintomatología(AU)

Introduction: The new coronavirus called SARS-Cov-2 has caused a severe outbreak of the disease called COVID-19. This virus was identified for the first time in Wuhan, China on December,2019. There were recently described its cutaneous manifestations, with clinical similarities among children and adults. There were identified five cutaneous patterns: macular-papular rash, hives, acral lesions pernicious type, vesicular rash and livedo reticularis. Objective: To characterize pediatric patients with cutaneous manifestations during COVID-19 disease. Cases presentation: There were studied 10 pediatric patients with COVID-19 admitted in ´´Comandante Manuel Piti Fajardo´´ Military Hospital of Villa Clara province. From the total of patients, eight presented eritemato-papular rash and two had urticariform rash. Urticariform lesions were present just in the girls, the eritomato-papulosa lesions presented similarly in both sexes with slight predominance in female adolescents. Both types of lesions appeared with predominance in the torso and accompanied of slight or absent pruritus. Just the urticariform lesions required medical treatment. Conclusions: The main clinical presentations in the pediatric population attended in the Military Hospital of Villa Clara province are the cutaneous manifestations. Eritemato-papular lesions are the most frequent; they have late onset and favorable evolution with no need of treatment and with no other symptomatology(AU)

Neumonía por SARS CoV-2 en lactante de cinco meses / Pneunomia by SARS CoV-2 in five months old newborn

Introducción: Las neumonías adquiridas en la comunidad tienen un índice elevado de morbilidad en la edad pediátrica, además continúa siendo la principal causa infecciosa de muerte en los países subdesarrollados. Los casos pediátricos documentados con COVID-19 son menos frecuentes que en adultos y de carácter más leve de forma general, especialmente en lactantes. En Cuba más de 70 por ciento de los pacientes pediátricos positivos a la COVID-19 han desarrollado la enfermedad de manera asintomática. Objetivo: describir las características de paciente pediátrico asintomático con neumonía por SARS CoV-2. paciente pediátrico asintomático con neumonía por SARS CoV-2. Presentación del caso: lactante de cinco meses, que ingresa con una prueba de reacción en cadena de la polimerasa positiva al nuevo coronavirus. Al ingresar se diagnosticó una neumonía por radiografía de tórax, pues se encontraba asintomático. Se comenzó tratamiento según protocolo con kaletra, cloroquina y ceftriaxone, con evidente mejoría durante su estadía hospitalaria. Conclusiones: La neumonía por SARS CoV-2 en la edad pediátrica suele cursar clínicamente asintomática y es fundamental mantener un alto índice de sospecha ante esta entidad, que, en la mayoría de las veces, su diagnóstico es únicamente imagenológico(AU)

Introduction: Pneumonias adquired in the community have a high rate of morbility in pediatric ages, besides it is still the main infectious cause of death in developing countries. Pediatric cases recorded with COVID-19 are less frequent than in adults and with lighter features in general sense, specially in newborns. In Cuba more than 70 percent of pediatric patients possitive to COVID-19 have developed the disease as asymptomatics. Objective: To describe the characteristics of an asymptomatic pediatric patient with pneumonia caused by SARS-Cov-2. Case presentation: Five months old newborn admitted in hospital after a polimerase´s chain reaction test (PCR) possitive to the new coronavirus. At the admittion time as the patient was asymptomatic, it was diagnosed pneumonia by thorax X-ray. It was started a treatment according to the protocol with kaletra chloroquine and ceftriaxone, with evident improvement during the hospital stay. Conclusions: Pneumonia caused by SARS CoV-2 in pediatric ages normally evolves clinically asymptomatic and it is essencial to keep a high rate of suspicion towards this entity which in most of the cases its diagnosis is only by imaging studies(AU)

Atomic iron and titanium in the atmosphere of the exoplanet KELT-9b.

To constrain the formation history of an exoplanet, we need to know its chemical composition1-3. With an equilibrium temperature of about 4,050 kelvin4, the exoplanet KELT-9b (also known as HD 195689b) is an archetype of the class of ultrahot Jupiters that straddle the transition between stars and gas-giant exoplanets and are therefore useful for studying atmospheric chemistry. At these high temperatures, iron and several other transition metals are not sequestered in molecules or cloud particles and exist solely in their atomic forms5. However, despite being the most abundant transition metal in nature, iron has not hitherto been detected directly in an exoplanet because it is highly refractory. The high temperatures of KELT-9b imply that its atmosphere is a tightly constrained chemical system that is expected to be nearly in chemical equilibrium5 and cloud-free6,7, and it has been predicted that spectral lines of iron should be detectable in the visible range of wavelengths5. Here we report observations of neutral and singly ionized atomic iron (Fe and Fe+) and singly ionized atomic titanium (Ti+) in the atmosphere of KELT-9b. We identify these species using cross-correlation analysis8 of high-resolution spectra obtained as the exoplanet passed in front of its host star. Similar detections of metals in other ultrahot Jupiters will provide constraints for planetary formation theories.

Ventilación mecánica en la enfermedad broncopulmonar obstructiva crónica reagudizada / Mechanical ventilation in the disease COPD

Ventilación mecánica en pacientes con EBPOC ha sido siempre un reto y la mortalidad es en la mayoría de los casos elevada, así como la incidencia de complicaciones. Por otro lado, es a veces imprescindible ventilarlos pacientes con este tipo de patología. En el presente artículo se revisan las estadísticas publicadas, indicaciones mas frecuentes para ventilación mecánica en este tipo de pacientes, y los mecanismos fisiopatológicos por los que se desarrolla la insuficiencia respiratoria. Por otra parte, se presentan casos manejados en ventilación mecánica, reportándose que la mortalidad es menor cuando los pacientes en estas condiciones se les logra extubar tempranamente (antes de las 24 horas)