Highly sensitive scent-detection of COVID-19 patients in vivo by trained dogs.

Timely and accurate diagnostics are essential to fight the COVID-19 pandemic, but no test satisfies both conditions. Dogs can scent-identify the unique odors of volatile organic compounds generated during infection by interrogating specimens or, ideally, the body of a patient. After training 6 dogs to detect SARS-CoV-2 by scent in human respiratory secretions (in vitro diagnosis), we retrained 5 of them to search and find the infection by scenting the patient directly (in vivo screening). Then, efficacy trials were designed to compare the diagnostic performance of the dogs against that of the rRT-PCR in 848 human subjects: 269 hospitalized patients (COVID-19 prevalence 30.1%), 259 hospital staff (prevalence 2.7%), and 320 government employees (prevalence 1.25%). The limit of detection in vitro was lower than 10-12 copies ssRNA/mL. During in vivo efficacy experiments, our 5 dogs detected 92 COVID-19 positive patients among the 848 study subjects. The alert (lying down) was immediate, with 95.2% accuracy and high sensitivity (95.9%; 95% C.I. 93.6-97.4), specificity (95.1%; 94.4-95.8), positive predictive value (69.7%; 65.9-73.2), and negative predictive value (99.5%; 99.2-99.7) in relation to rRT-PCR. Seventy-five days after finishing in vivo efficacy experiments, a real-life study (in vivo effectiveness) was executed among the riders of the Metro System of Medellin, deploying the human-canine teams without previous training or announcement. Three dogs were used to examine the scent of 550 volunteers who agreed to participate, both in test with canines and in rRT-PCR testing. Negative predictive value remained at 99.0% (95% C.I. 98.3-99.4), but positive predictive value dropped to 28.2% (95% C.I. 21.1-36.7). Canine scent-detection in vivo is a highly accurate screening test for COVID-19, and it detects more than 99% of infected individuals independent of key variables, such as disease prevalence, time post-exposure, or presence of symptoms. Additional training is required to teach the dogs to ignore odoriferous contamination under real-life conditions.

Redescription and phylogenetics of emAllobates/em emtrilineatus/em (Boulenger 1884 "1883") (Anura: Aromobatidae) based on topotypic specimens.

Allobates trilineatus is the second most geographically widespread species in the genus Allobates, its range extending from northern Ecuador to southern Peru along the Andean foothills of Amazonia and to the east, into Acre, Brazil. However, detailed phenotypic and genetic variation from topotypic specimens is lacking, raising doubts about the identification of specimens in the literature. To solve this problem, we collected 16 topotypic specimens-including male and female adults and juveniles-and associated data such as advertisement calls and tissue samples. Based upon this material, we redescribe the phenotypic variation within A. trilineatus and evaluate its phylogenetic position using a fragment of the mitochondrial gene 16S rDNA. Allobates trilineatus is distinguished from its congeners by its small body size (adult snout-to-vent-length = 14.6-16.6 mm), preserved males with dark gray throat, and gray chest and belly, pale dorsolateral stripe straight and conspicuous, and advertisement call formed by the emission of groups of note-pairs with dominant frequency at 5.06-5.81 kHz. Our phylogenetic results indicate that none of the specimens assigned to this species in previous phylogenetic studies cluster within the clade formed by topotypic samples, except for the sample of one tadpole. Furthermore, our comparison of published phenotypic and genetic data assigned to A. trilineatus with our new data led us to conclude that A. trilineatus as previously recognized was actually a complex of cryptic, closely related species. Although with the data at hand we cannot fully resolve the taxonomy of all sampled populations in previous studies, we provide a new definition and delimitation of A. trilineatus sensu stricto, assign other specimens to different evolutionary units corresponding to candidate species, and flag other important taxonomic issues.

Vastly underestimated species richness of Amazonian salamanders (Plethodontidae: Bolitoglossa) and implications about plethodontid diversification.

We present data showing that the number of salamander species in Amazonia is vastly underestimated. We used DNA sequences of up to five genes (3 mitochondrial and 2 nuclear) of 366 specimens, 189 corresponding to 89 non-Amazonian nominal species and 177 Amazonian specimens, including types or topotypes, of eight of the nine recognized species in the region. By including representatives of all known species of Amazonian Bolitoglossa, except for one, and 73% of the currently 132 recognized species of the genus, our dataset represents the broadest sample of Bolitoglossa species, specimens, and geographic localities studied to date. We performed phylogenetic analyses using parsimony with tree-alignment and maximum likelihood (ML) with similarity alignment, with indels as binary characters. Our optimal topologies were used to delimit lineages that we assigned to nominal species and candidate new species following criteria that maximize the consilience of the current species taxonomy, monophyly, gaps in branch lengths, genetic distances, and geographic distribution. We contrasted the results of our species-delimitation protocol with those of Automated Barcode Gap Discovery (ABGD) and multi-rate Poisson Tree Processes (mPTP). Finally, we inferred the historical biogeography of South American salamanders by dating the trees and using dispersal-vicariance analysis (DIVA). Our results revealed a clade including almost all Amazonian salamanders, with a topology incompatible with just the currently recognized nine species. Following our species-delimitation criteria, we identified 44 putative species in Amazonia. Both ABGD and mPTP inferred more species than currently recognized, but their numbers (23-49) and limits vary. Our biogeographic analysis suggested a stepping-stone colonization of the Amazonian lowlands from Central America through the Chocó and the Andes, with several late dispersals from Amazonia back into the Andes. These biogeographic events are temporally concordant with an early land bridge between Central and South America (~10-15 MYA) and major landscape changes in Amazonia during the late Miocene and Pliocene, such as the drainage of the Pebas system, the establishment of the Amazon River, and the major orogeny of the northern Andes.

Solvothermal Synthesis and Photocatalytic Activity of BiOBr Microspheres with Hierarchical Morphologies.

BiOBr microspheres with hierarchical morphologies (BiOBr-MicSphe) has potential application in heterogeneous photocatalysis for decontamination of water and air. For this reason, the synthesis, characterization an evaluation of photocatalytic activity of these materials become important. In this article, BiOBr-MicSphe were synthesized using different ranges of reaction temperature (120-200 °C) and reaction time (12 h - 24 h). Samples grown at 145 °C and 18 h showed the higher photocatalytic activity on gallic acid degradation. Morphological properties, chemical composition and structural analysis revealed that sample with higher photocatalytic activity exhibited a microspherical morphology with pure BiOBr tetragonal phase. Besides, adsorption-desorption analysis showed a smaller pore diameter for sample grown at 145 °C and 18 hrs. The results showed that the reaction temperature has a strong influence on the different properties of the material, affecting the photocatalytic activity.

Encuesta nacional de analgesia y anestesia obstétrica: ¿Cómo se trabaja entre nosotros? / National survey of analgesia and obstetric anesthesia: How works itself among us?

Esta encuesta fue dirigida a 40 instituciones del país, con el fin de determinar que técnicas son utilizadas para el alivio del dolor en el trabajo de parto y la anestesia en caso de intervención cesárea o parto instrumentado así como para la evaluación de los recursos básicos de la práctica diaria, y diseñar estrategias encaminadas a mejorar la atención del binomio madre feto. Se realizó un estudio descriptivo, prospectivo en 40 centros que prestan atención obstétrica e hicieran parte de una filial de la Sociedad Colombiana de Anestesiología; por medio del método de encuesta, enviada por correo, fax o entregada personalmente. Se empleo el programa Excel para el registro y análisis de los datos, obteniéndose las frecuencias absolutas y relativas de cada variable de manera independiente. El índice de respuesta fue del 67.5 por ciento. El 77.8 por ciento de los centros tienen la disponibilidad de brindar analgesia para el trabajo de parto, el 76.2 por ciento utilizan mezclas analgésicas con concentraciones de Bupivacaina menores de 0.25 por ciento. El 92.6 por ciento utiliza técnica espinal para cesárea. Las técnicas regionales son las de elección tanto para cesárea electiva como urgente. Esta es el primer estudio colombiano tipo encuesta (Survey) que evalúa los recursos y las técnicas básicas empleadas en analgesia / anestesia obstétrica. Palabras Claves: Analgesia, Anestesia obstétrica...

Extubación temprana (fast-track) en neuroanestesia: ¿Una alternativa segura? / Extubación early (fast-track) in neuroanestesia: A sure alternative?

Las técnicas de transito rápido (fast y track) han impactado la práctica de la disciplina, desde áreas tan diversas como cardioanestesia a anestesia ambulatoria sin quedar fuera de este movimiento la neuroanestesia. Teniendo en este contexto una repercusión aun mayor, fundamentada en que la evaluación de la condición neurológica en un paciente despierto, es el método mejor y menos costoso de neuromonitoreo disponible; pero a pesar de la premisa anterior la aplicación de este tipo de protocolos en neurocirugía debe ser vista como un trabajo en equipo, para que la ejecución de la técnica no sea detrimente para el resultado final. Por eso durante esta revisión pretendemos evaluar el papel del fast y track en neuroanestesia, teniendo en cuenta las repercusiones fisopatològicas y por ende los pros y contras del despertar temprano vs. tardío; generando las bases para la elaboración de un posible plan anestésico para tránsito rápido, por que finalmente la emergencia anestésica y extubación temprana en neuroanestesia es deseable y posible en la mayoría de los casos, lo cual es esencial para detectar complicaciones postoperatorias a la llegada a recuperación...