Single-Molecule Identification of the Isomers of a Lipidic Antibody Activator.

Molecular structural elucidation can be accomplished by different techniques, such as nuclear magnetic resonance or X-ray diffraction. However, the former does not give information about the three-dimensional atomic arrangement, and the latter needs crystallizable solid samples. An alternative is direct, real-space visualization of the molecules by cryogenic scanning tunneling microscopy (STM). This technique is usually limited to thermally robust molecules because an annealing step is required for sample deposition. A landmark development has been the coupling of STM with electrospray deposition (ESD), which smooths the process and widens the scope of the visualization technique. In this work, we present the on-surface characterization of air-, light-, and temperature-sensitive rhamnopolyene with relevance in molecular biology. Supported by theoretical calculations, we characterize two isomers of this flexible molecule, confirming the potential of the technique to inspect labile, non-crystallizable compounds.

Thermal niche breadth and their relationship with sturnira bat species diversification.

The interaction between climatic conditions and the ability of organisms to maintain homeostasis regulates the distribution of species on the planet. However, its influence on macroevolutionary dynamics is not well understood. It has been suggested that diversification rates will be different in lineages with narrow thermal niches (specialists) to diversification rates in generalist lineages, but the evidence for this is elusive. Here, we tested this hypothesis by using the most diverse (in species richness and geographic range variation) tropical bat genus within the Phyllostomidae family. We estimated the realized thermal niche breadth of Sturnira species from their geographic range and categorized them as generalists, cold specialists, or warm specialists. We compared dynamic evolutionary models that differ in 1) niche breadth evolution, 2) parental niche breadth inheritance, and 3) whether niche breadth evolution is associated with shifts in diversification rates. Our best-performing model indicates that most Sturnira species arose as specialists in warm climates and that over time, their niche breadth broadens, and just a subset of those species becomes specialists in cold environments. We found that the evolution of realized thermal niche breadth causes fluctuations in per-lineage rates of diversification, where warm specialists boast the highest speciation rates. However, we found no evidence of these changes in niche neither triggering nor being a result of speciation events themselves; this suggests that diversification events in Sturnira could instead depend on allopatric speciation processes such as the development of geographic barriers.

On-surface synthesis of non-benzenoid conjugated polymers by selective atomic rearrangement of ethynylarenes.

Here, we report a new on-surface synthetic strategy to precisely introduce five-membered units into conjugated polymers from specifically designed precursor molecules that give rise to low-bandgap fulvalene-bridged bisanthene polymers. The selective formation of non-benzenoid units is finely controlled by the annealing parameters, which govern the initiation of atomic rearrangements that efficiently transform previously formed diethynyl bridges into fulvalene moieties. The atomically precise structures and electronic properties have been unmistakably characterized by STM, nc-AFM, and STS and the results are supported by DFT theoretical calculations. Interestingly, the fulvalene-bridged bisanthene polymers exhibit experimental narrow frontier electronic gaps of 1.2 eV on Au(111) with fully conjugated units. This on-surface synthetic strategy can potentially be extended to other conjugated polymers to tune their optoelectronic properties by integrating five-membered rings at precise sites.

Impacto del uso de la mascarilla durante la realización de la prueba de esfuerzo en tapiz rodante / Impact of face masks during the treadmill exercise tests

Introducción y objetivos: Existe poca literatura sobre el uso de la mascarilla en la realización de una prueba de esfuerzo (PE) durante la pandemia de COVID-19. El objetivo de este estudio es analizar el impacto del uso de la mascarilla durante la realización de una PE en un grupo de pacientes que han realizado al menos una PE con y sin mascarilla.MétodosEstudio observacional retrospectivo unicéntrico de pacientes sometidos a una PE con tapiz rodante. El criterio de inclusión fue tener más de 16años y haber realizado al menos una PE en época prepandemia (sin mascarilla) y pospandemia (con mascarilla).ResultadosUn total de 1.655 pacientes fueron incluidos en el estudio; 935 (56,5%) eran varones y 720 (43,5%) eran mujeres. La edad media fue de 57,3±14,9 años y el tiempo medio de seguimiento fue de 15,4 meses. El 53% de los pacientes presentaron antecedentes personales de hipertensión arterial; el 20%, dislipemia; el 12%, diabetes mellitus; el 8%, hábito tabáquico; el 19%, cardiopatía isquémica; el 5%, EPOC; el 8%, asma bronquial, y el 8%, fibrilación auricular. En la casi totalidad de las variables estudiadas en la PE, incluida la aparición de arritmias ventriculares, no se evidenciaron diferencias significativas, ni por edad ni por sexo, salvo la existencia de una muy leve disminución en la capacidad de ejercicio con el uso de mascarilla en los pacientes de mayor edad (>65años).ConclusionesEl uso de mascarillas quirúrgicas o FFP2 durante la PE no afectó a la capacidad funcional, a la presión arterial, a la frecuencia cardiaca ni incrementó las arritmias ventriculares. (AU)

Introduction and objective: There is little literature on the use of face masks in a treadmill test (TMT) during the COVID-19 pandemic. The objective of this study is to analyze the impact of face masks during a TMT performed during the prepandemic (without face mask) and postpandemic (with face mask) era.MethodsRetrospective observational unicentric study of patients undergoing TMT. The inclusion criterion were being over 16years old and having performed at least one TMT in the prepandemic and postpandemic period.ResultsOne thousand six hundred fifty-five patients were included in the study. Nine hundred thirty-five (56.5%) were men and 720 (43.5%) women. The mean age was 57.3±14.9 and the mean follow-up time was 15.4 months. Fifty-three percent patients had arterial hypertension, 20% dyslipidemia, 12% diabetes mellitus, 8% smoking habit, 19% personal history of ischemic heart disease, 5% COPD, 8% bronchial asthma, and 8% atrial fibrillation. In almost all the variables studied in PE, including the appearance of ventricular arrhythmias, no significant differences were found, neither by age nor sex, except for the existence of a very slight decrease in exercise capacity with mask use in older patients (>65years).ConclusionsThe use of surgical or FFP2 face masks during the TMT did not affect functional capacity, blood pressure, heart rate, or increased ventricular arrhythmias. (AU)

Impact of face masks during the treadmill exercise tests. / Impacto del uso de la mascarilla durante la realización de la prueba de esfuerzo en tapiz rodante.

INTRODUCTION AND OBJECTIVE: There is little literature on the use of face masks in a treadmill test (TMT) during the COVID-19 pandemic. The objective of this study is to analyze the impact of face masks during a TMT performed during the prepandemic (without face mask) and postpandemic (with face mask) era. METHODS: Retrospective observational unicentric study of patients undergoing TMT. The inclusion criterion were being over 16years old and having performed at least one TMT in the prepandemic and postpandemic period. RESULTS: One thousand six hundred fifty-five patients were included in the study. Nine hundred thirty-five (56.5%) were men and 720 (43.5%) women. The mean age was 57.3±14.9 and the mean follow-up time was 15.4 months. Fifty-three percent patients had arterial hypertension, 20% dyslipidemia, 12% diabetes mellitus, 8% smoking habit, 19% personal history of ischemic heart disease, 5% COPD, 8% bronchial asthma, and 8% atrial fibrillation. In almost all the variables studied in PE, including the appearance of ventricular arrhythmias, no significant differences were found, neither by age nor sex, except for the existence of a very slight decrease in exercise capacity with mask use in older patients (>65years). CONCLUSIONS: The use of surgical or FFP2 face masks during the TMT did not affect functional capacity, blood pressure, heart rate, or increased ventricular arrhythmias.

On-Surface Thermal Stability of a Graphenic Structure Incorporating a Tropone Moiety.

On-surface synthesis, complementary to wet chemistry, has been demonstrated to be a valid approach for the synthesis of tailored graphenic nanostructures with atomic precision. Among the different existing strategies used to tune the optoelectronic and magnetic properties of these nanostructures, the introduction of non-hexagonal rings inducing out-of-plane distortions is a promising pathway that has been scarcely explored on surfaces. Here, we demonstrate that non-hexagonal rings, in the form of tropone (cycloheptatrienone) moieties, are thermally transformed into phenyl or cyclopentadienone moieties upon an unprecedented surface-mediated retro-Buchner-type reaction involving a decarbonylation or an intramolecular rearrangement of the CO unit, respectively.

Body mass explains digestive traits in small vespertilionid bats.

Bats are unique among mammals in that they have evolved the capacity to fly. This has generated strong selective pressure on the morphology and function of their digestive system. Given that in bats intestinal length and nominal surface-area are proportional to body mass, this trait importantly relates to explaining some of their digestive characteristics. We described the relationship between digestive traits and body mass of four species of bats of the family Vespertilionidae living in a montane ecosystem in central Mexico. We calculated food transit time, apparent dry matter digestibility, and defecation rate in feeding trials under captive conditions. We also: (1) built a model of the relationship between digestive traits and body mass to determine if this association was consistent within the members of the family Vespertilionidae, and (2) mapped these traits along the phylogeny to explore how digestive characteristics may have evolved. In our feeding trials, body mass was positively related to transit time and negatively related to apparent dry matter digestibility. The model predicted accurately the transit time in bats with body mass < 20 g. The phylogenetic approach suggested that over the evolutionary history of the family, transit time decreased as digestibility increased. Because of the results obtained here, it is likely that for most bats of the family Vespertilionidae, adaptations in digestive traits to process food have followed evolutionary changes in their body mass. We discuss these findings in a physiological and ecological context.

Impact of monitoring on detection of arrhythmia recurrences in the ESC-EHRA EORP atrial fibrillation ablation long-term registry.

AIMS: Monitoring of patients after ablation had wide variations in the ESC-EHRA atrial fibrillation ablation long-term (AFA-LT) registry. We aimed to compare four different monitoring strategies after catheter AF ablation. METHODS AND RESULTS: The ESC-EHRA AFA-LT registry included 3593 patients who underwent ablation. Arrhythmia monitoring during follow-up was performed by 12-lead electrocardiogram (ECG), Holter ECG, trans-telephonic ECG monitoring (TTMON), or an implanted cardiac monitoring (ICM) system. Patients were selected to a given monitoring group according to the most extensive ECG tool used in each of them. Comparison of the probability of freedom from recurrences was performed by censored log-rank test and presented by Kaplan-Meier curves. The rhythm monitoring methods were used among 2658 patients: ECG (N = 578), Holter ECG (N = 1874), TTMON (N = 101), and ICM (N = 105). A total of 767 of 2658 patients (28.9%) had AF recurrences during follow-up. Censored log-rank test discovered a lower probability of freedom from relapses, which was detected with ICM compared to TTMON, ECG, and Holter ECG (P < 0.001). The rate of freedom from AF recurrences was 50.5% among patients using the ICM while it was 65.4%, 70.6%, and 72.8% using the TTMON, ECG, and Holter ECG, respectively. CONCLUSION: Comparing all main electrocardiographic monitoring methods in a large patient sample, our results suggest that post-ablation recurrences of AF are significantly underreported by TTMON, ECG, and Holter ECG. The ICM estimates AF ablation recurrences most reliably and should be a preferred mode of monitoring for trials evaluating novel AF ablation techniques.

Risk stratification of cardiovascular and heart failure hospitalizations using integrated device diagnostics in patients with a cardiac resynchronization therapy defibrillator.

Aims: Cardiac resynchronization therapy defibrillators (CRT-D) are able to monitor various parameters that may be combined by an automatic algorithm to provide a heart failure risk status (HFRS). We sought to validate the HFRS for stratifying patient risk, evaluate its association with heart failure (HF) symptoms, and investigate its utility for triage of automatic alerts. Methods and results: Data from 722 patients included in the MORE-CARE trial were analysed in a post hoc analysis. A high HFRS was associated with a significantly increased risk of admission over the next 30 days with a relative risk for cardiovascular hospitalization (CVH) of 4.5 (95% CI: 3.1-6.6, P < 0.001), of HF hospitalization of 6.3 (95% CI: 3.9-10.2, P < 0.001) and of non-HF related CVH of 3.5 (95% CI: 2.0-6.9, P < 0.001). The negative predictive value of low or medium HFRS for these admissions was ≥98%. A high HFRS was associated with an increased risk of HF symptoms. Of all the automatic remote monitoring alerts generated during the study, only 10% had a high HFRS. Conclusion: The HFRS is able to risk-stratify CRT-D patients, which is potentially useful for managing automatic remote monitoring alerts, by focusing attention on the minority of high-risk patients. Clinical Trial Registration: The trial was registered at www.clinicaltrials.gov under number NCT00885677.

Miocardiopatía hipertrófica sin hipertrofia ventricular: utilidad del estudio anatomopatológico y genético en la prevención de la muerte súbita / Hypertrophic cardiomyopathy without ventricular hypertrophy: usefulness of genetic and pathological study in preventing sudden death

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Mesoamerican tree squirrels evolution (Rodentia: Sciuridae): a molecular phylogenetic analysis.

The tribe Sciurini comprehends the genera Sciurus, Syntheosiurus, Microsciurus, Tamiasciurus and Rheinthrosciurus. The phylogenetic relationships within Sciurus have been only partially done, and the relationship between Mesoamerican species remains unsolved. The phylogenetic relationships of the Mesoamerican tree squirrels were examined using molecular data. Sequence data publicly available (12S, 16S, CYTB mitochondrial genes and IRBP nuclear gene) and cytochrome B gene sequences of four previously not sampled Mesoamerican Sciurus species were analyzed under a Bayesian multispecies coalescence model. Phylogenetic analysis of the multilocus data set showed the neotropical tree squirrels as a monophyletic clade. The genus Sciurus was paraphyletic due to the inclusion of Microsciurus species (M. alfari and M. flaviventer). The South American species S. aestuans and S. stramineus showed a sister taxa relationship. Single locus analysis based on the most compact and complete data set (i.e. CYTB gene sequences), supported the monophyly of the South American species and recovered a Mesoamerican clade including S. aureogaster, S. granatensis and S. variegatoides. These results corroborated previous findings based on cladistic analysis of cranial and post-cranial characters. Our data support a close relationship between Mesoamerican Sciurus species and a sister relationship with South American species, and corroborates previous findings in relation to the polyphyly of Microsciurus and Syntheosciurus paraphyly.

Mesoamerican tree squirrels evolution (Rodentia: Sciuridae): a molecular phylogenetic analysis / Evolución de las ardillas arborícolas mesoamericanas (Rodentia: Sciuridae): un análisis filogenético molecular

The tribe Sciurini comprehends the genera Sciurus, Syntheosiurus, Microsciurus, Tamiasciurus and Rheinthrosciurus. The phylogenetic relationships within Sciurus have been only partially done, and the relationship between Mesoamerican species remains unsolved. The phylogenetic relationships of the Mesoamerican tree squirrels were examined using molecular data. Sequence data publicly available (12S, 16S, CYTB mitochondrial genes and IRBP nuclear gene) and cytochrome B gene sequences of four previously not sampled Mesoamerican Sciurus species were analyzed under a Bayesian multispecies coalescence model. Phylogenetic analysis of the multilocus data set showed the neotropical tree squirrels as a monophyletic clade. The genus Sciurus was paraphyletic due to the inclusion of Microsciurus species (M. alfari and M. flaviventer). The South American species S. aestuans and S. stramineus showed a sister taxa relationship. Single locus analysis based on the most compact and complete data set (i.e. CYTB gene sequences), supported the monophyly of the South American species and recovered a Mesoamerican clade including S. aureogaster, S. granatensis and S. variegatoides. These results corroborated previous findings based on cladistic analysis of cranial and post-cranial characters. Our data support a close relationship between Mesoamerican Sciurus species and a sister relationship with South American species, and corroborates previous findings in relation to the polyphyly of Microsciurus and Syntheosciurus’ paraphyly. Rev. Biol. Trop. 62 (2): 649-657. Epub 2014 June 01.

La tribu Sciurini comprende los géneros Sciurus, Syntheosciurus, Microsciurus, Tamiasciurus y Rheinthrosciurus. Las relaciones filogenéticas de Sciurus han sido resueltas parcialmente mientras que las relaciones de las especies Mesoamericanas permanecen sin resolverse. Las relaciones filogenéticas de las ardillas arborícolas mesoamericanas fueron estudiadas empleando datos moleculares. Datos de secuencias disponibles de forma pública (genes mitocondriales CYTB, 12S, 16S y gen nuclear IRBP) en conjunto con secuencias nuevas para el gen del Citocromo B de 4 especies mesoamericanas del genero Sciurus, fueron analizadas empleando un modelo bayesiano de coalescencia multi-especie. Los análisis filogenéticos del conjunto de datos multilocus mostraron que las especies neotropicales forman un clado monofilético. El género Sciurus resulto ser parafilético debido a la inclusión de las especies de Microsciurus (M. alfari y M. flaviventer). Las especies suramericanas S. aestuans y S. stramineus presentaron una relación de especies hermanas. El análisis de un solo locus basado en el conjunto de datos más compacto y completo (secuencias del gen del citocromo B), apoyó la naturaleza monofilética de las especies suramericanas y recuperó un clado mesoamericano que incluye a S. aureogaster, S. granatensis y S. variegatoides. Estos resultados corroboran los descubrimientos previos que emplearon datos morfológicos craneales y pos-craneales. Nuestros datos apoyan la relación cercana entre las especies de Sciurus Mesoamericanas y la relación hermana de estas con las especies de Suramérica, así como también corroboran la relación polifilética de Microsciurus y parafilética de Syntheosciurus previamente reportadas.

Panbiogeographical analysis of Costa Rican freshwater fishes.

Track analysis and Parsimony analysis of endemicity (PAE) were performed to analyze the distribution pattern of Costa Rican freshwater fishes. A basic matrix (presence/absence) was prepared using the distribution of 77 freshwater fish. The data were analyzed with CLIQUE software in order to find generalized tracks (cliques). Data also were analyzed with the software NONA and Winclada version 1.00.08 in order to perform the Parsimony Analysis of Endemicity (PAE). Fourteen equally probable cliques were found with 31 species in each and the intersection of the amount was selected as a generalized track dividing the country in two main zones: Atlantic slope from Matina to Lake Nicaragua and Pacific slope from the Coto River to the basin of the Tempisque River connected with some branches oriented to the central part of the country. PAE analysis found ten cladogram areas (72 steps, CI=0.45, RI=0.64), using the "strict consensus option" two grouping zones were identified: Atlantic slope and Pacific slope. Both PAE and Track Analysis show the division of the two slopes and the orientation of the generalized track suggests new biogeographical evidence on the influence of both old and new southern elements to explain the migrations of freshwater fish into Central America during two different geological events.

Panbiogeographical analysis of Costa Rican freshwater fishes

Track analysis and Parsimony analysis of endemicity (PAE) were performed to analyze the distribution pattern of Costa Rican freshwater fishes. A basic matrix (presence/absence) was prepared using the distribution of 77 freshwater fish. The data were analyzed with CLIQUE software in order to find generalized tracks (cliques). Data also were analyzed with the software NONA and Winclada version 1.00.08 in order to perform the Parsimony Analysis of Endemicity (PAE). Fourteen equally probable cliques were found with 31 species in each and the intersection of the amount was selected as a generalized track dividing the country in two main zones: Atlantic slope from Matina to Lake Nicaragua and Pacific slope from the Coto River to the basin of the Tempisque River connected with some branches oriented to the central part of the country. PAE analysis found ten cladogram areas (72 steps, CI=0.45, RI=0.64), using the "strict consensus option" two grouping zones were identified: Atlantic slope and Pacific slope. Both PAE and Track Analysis show the division of the two slopes and the orientation of the generalized track suggests new biogeographical evidence on the influence of both old and new southern elements to explain the migrations of freshwater fish into Central America during two different geological events.

Con el objetivo de analizar el patrón de distribución de peces de agua dulce de Costa Rica se aplicó un análisis de trazos y de parsimonía de endemismos (PAE). Se construyó una matriz básica utilizando la distribución de 77 especies. Se utilizó el programa CLIQUE con la intención de encontrar los trazos generalizados y NONA y Winclada, versión 1.00.08, con el fin de llevar a cabo el PAE. Se encontró un total de 14 cliques igualmente probables con 31 especies. De esta cantidad se construyó un trazo generalizado que constituye la intersección del total, dividiendo el país en dos zonas: Atlántico, desde Matina hasta el Lago de Nicaragua y Pacífico desde el río Coto hasta el río Tempisque conectado con la región central del país. El PAE encontró diez cladogramas de áreas (72 pasos, CI=0.45, RI=0.64), cuyo consenso estricto identificó dos zonas de agrupamiento: Atlántico y Pacífico. Ambos análisis muestran la división entre las dos vertientes y la orientación de los trazos generalizados sugiere nueva evidencia de la influencia biogeográfica de los denominados elementos de migración antiguo y nuevo del sur, los cuales se habían sugerido empíricamente en el pasado para explicar las migraciones hacia Centroamérica en dos periodos geológicos diferentes.

A phylogeny of howler monkeys (Cebidae: Alouatta) based on mitochondrial, chromosomal and morphological data

The current taxonomic status of the species and subspecies belonging to the genus Alouatta is addressed by combined phylogenetic analysis using morphological, kariotipyc and molecular data (mitochondrial genes cytocrome oxidase II and cytochrome B). Our result demonstrated that Alouatta palliata is the most basal taxon for the genus in concordance with previous studies, as well as showing the validity of the taxon Alouatta sara as a species. Also our analysis shows that the sex chromosome has evolved from a XY/XX system to a X1X2Y1Y2/X1X1X2X2 system within the genus, as well as an increase in the size and complexity of the hioideal bone.

A phylogeny of howler monkeys (Cebidae: Alouatta) based on mitochondrial, chromosomal and morphological data.

The current taxonomic status of the species and subspecies belonging to the genus Alouatta is addressed by combined phylogenetic analysis using morphological, kariotipyc and molecular data (mitochondrial genes cytocrome oxidase II and cytochrome B). Our result demonstrated that Alouatta palliata is the most basal taxon for the genus in concordance with previous studies, as well as showing the validity of the taxon Alouatta sara as a species. Also our analysis shows that the sex chromosome has evolved from a XY/XX system to a X1X2Y1Y2/X1X1X2X2 system within the genus, as well as an increase in the size and complexity of the hioideal bone.