Response of phyllostomid bat diversity to tree cover types in North-western Ecuador.

Agricultural activities affect tropical forest biodiversity; however, some bat species can survive under these anthropogenic changes. We described the characteristics of phyllostomid bat assemblages in tree covers located in 48 plots among four agricultural landscapes of North-western Ecuador. Bats were captured with mist nets installed at a ground level reaching three meters' height. For each of the plots, we installed a mist net in four types of tree cover (polyspecific live fences, monospecific live fences, cacao plantations, and isolated trees in pastures). We captured 250 phyllostomid bats belonging to 16 species with a trapping effort of 19,200 m2 of net coverage. Polyspecific live fences showed significant differences in relative abundance, richness, and diversity of phyllostomid bats compared to the other three. Frugivorous and nectarivorous guilds were the most abundant, and also exhibited the highest richness among other guilds present in agricultural landscapes. In addition, frugivorous, and nectarivorous guilds increase their abundance and richness in agricultural landscapes, while the animalivorous guild is negatively affected. We recommend installing polyspecific live fences in tropical production systems to support the conservation of phyllostomid bats. We conclude that living fences composed of various plant species favour the abundance, richness, and diversity of phyllostomid bats.

Catalytic activity of silicene biflakes for CO2 reduction: a theoretical approach.

The use of renewable energy sources to reduce carbon dioxide (CO2) emissions has gained significant attention in recent years. The catalytic reduction of CO2 into value-added products is a promising approach to achieve this goal, and silicene biflakes (2Si) have been identified as potential candidates for this task. In this study, we explored the catalytic activity of these structures using density functional theory calculations. Our results show that the reaction pathway involves the adsorption of CO2 onto the silicene surface, followed by the addition of hydrogen molecules to form products such as formic acid, methanol, methane, carbon monoxide, and formaldehyde. Our proposed mechanism indicates that silicene biflakes exhibit a higher affinity for CO2 than single-layer silicon. We also found that the hydrogenation with H2 occurs by adding one hydrogen atom to the absorbed CO2 and another to the surface of 2Si. Intermediate species are reduced by systematically adding hydrogen atoms and removing water molecules, forming formic acid as the most probable product. The rate-controlling step for this reaction has an energy of 32.9 kcal mol-1. In contrast, the process without a catalyst shows an energy of 74.6 kcal mol-1, suggesting that the silicon bilayer is a structure with outstanding potential to capture and reduce CO2. Our study provides important insights into the fundamental mechanisms underlying the silicene-mediated CO2 reduction and could facilitate the development of more efficient catalysts for this process.

Response of dung beetle diversity to remediation of soil ecosystems in the Ecuadorian Amazon.

Background: Efforts to alleviate the negative effects of oil spills in the Ecuadorian Amazon include remediation activities such as cleaning, reshaping, and revegetation of polluted areas. However, studies of the diversity of biological communities in these hydrocarbon-degraded ecosystems have never been carried out. Here, we evaluated the diversity of dung beetles on remediated soil ecosystems (Agricultural Soils and Sensitive Ecosystems) and on non-contaminated soils (Natural Forests and Palm Plantations). Methodology: The study was conducted in Sucumbíos and Orellana provinces, in the Ecuadorian Amazon at four sampling sites per ecosystem type (a total of 16 sites). At each sampling site, six pitfall traps remained active for 120 consecutive h per month for 1 year. Results: We collected 37 species and 7,506 individuals of dung beetles. We observed significant differences in mean species abundance, richness, and diversity between non-contaminated soil ecosystems and remediated soil ecosystems, with Natural Forests presenting the highest values, and Agricultural Soils the lowest values. Regarding sampling month, we also found significant differences among ecosystems, which were also higher in Natural Forests. Discussion: The results suggest that hydrocarbon-degraded ecosystems tend to conserve lower beetle diversity one year after remediation highlighting the importance of Natural Forests for the conservation of tropical biodiversity. Therefore, dung beetle diversity could be used for future landscape management of these hydrocarbon-degraded ecosystems.

Diagnosis of type 2 diabetes in a patient with acute sinusitis and COVID-19 in Colombia.

During the COVID-19 pandemic, cases of acute sinusitis due to COVID-19 and even co-infections have been reported [1]. We want to discuss a case in Colombia where a patient with detected type 2 diabetes presented sinusitis and COVID-19. A 51-year-old man from Sincelejo, Sucre, consulted on May 23, 2020, with one day presenting general malaise and fever (38 °C), lumbar pain, frequent urination, polydipsia and hyperglycemia (366 mg/dl). He denied cough, travel during the last two weeksan Physical examination revealed a blood pressure of 170/110 mmHg, heart rate of 115 beats/minute, respiratory rate of 16 breaths/minute, and temperature of 36.6 °C. Neither lymphadenopathies nor cardiopulmonary disturbances were noted. A working diagnosis of febrile syndrome, ketoacidosis, and recent-onset type 2 diabetes, with uncontrolled hypertension, was contemplated at admission RT-PCR for SARS-CoV-2 was positive. A head CT Scan revealed left maxillary sinusitis with mucosal thickening of the maxillary Despite the sizeable SARS-CoV-2 pandemic, the number of reports of sinusitis in association with COVID-19 has been limited [2,3]. Sinusitis is more often diagnosed among immunocompromised patients, including diabetes of our patient. COVID-19, as a multisystemic condition. It may affect different anatomical areas, including the paranasal sinuses and the upper and lower respiratory mucosa. Although it is uncertain whether SARS-CoV-2 was the sole cause of the sinusitis in our patient or just a contributing factor, other reports suggest a significant involvement of the virus in the development of this condition, in addition to its role in worsening the clinical course of patients with chronic rhinosinusitis.

Brote de enfermedad aguda de Chagas adquirida oralmente en Sucre, 2019-2020 / Outbreak of orally acquired acute Chagas disease in Sucre, 2019-2020

Introducción: En las dos últimas décadas, varios países de América Latina han experimentado múltiples brotes de la enfermedad de Chagas oral. El estudio: Estudio retrospectivo que analiza un brote de enfermedad de Chagas oral aguda en Sucre, Colombia durante diciembre-enero de 2020. Los casos fueron confirmados por diferentes métodos diagnósticos. Hallazgos: Durante dos semanas se confirmaron 16 casos, donde la edad media fue de 14 años. Del total, 14 pacientes fueron hospitalizados y 2 fallecieron. Las manifestaciones clínicas incluyeron: fiebre, edema facial, hepatoesplenomegalia. En 13 de los pacientes se observaron tripomastigotes de Trypanosoma cruzi en los frotis fino y grueso. La transmisión oral se estableció como la vía más probable. Conclusiones: La enfermedad de Chagas aguda transmitida por vía oral puede poner en peligro la vida o incluso ser mortal, por tanto, es urgente mejorar las medidas de control epidemiológico a nivel nacional y en otros países de América Latina.

Background:In the last two decades, several Latin Americancountrieshaveexperiencedmultiple outbreaksoforalChagasdisease.Thestudy: Retrospective study analyzing an outbreak of acute oralChagasdiseaseinSucre,Colombiaduring December-January 2020. The cases were confirmed by different diagnostic methods. During two Finding:weeks, 16 cases were confirmed, where the mean age was 14 years and 12 were male. Of the total, 14 patientswerehospitalizedand2died.Clinical manifestationsinclude:fever,facialedema, hepatosplenomegaly,In13ofthepatients Trypanosoma cruzi trypomastigotes were observed in thethinandthicksmears.Oraltransmissionis established as the most likely route in 14 of the patients. Acute orally transmitted Conclusions: Chagas disease can be life-threatening or even fatal, therefore, it is urgent to improve epidemiological control measures at the national level and in other Latin American countries.

Water clusters as bifunctional catalysts in organic chemistry: the hydrolysis of oxirane and its methyl derivatives.

This contribution explores the bifunctional catalytic activity of water clusters ((H2O)n with n = 1-5) in organic chemistry similar to that observed in the formation of H2SO4 in acid rain (Chem. Commun., 53, 3516, (2017)). We considered for this purpose the Hydrolysis of Epoxides (HE), in particular, that of oxirane and its methyl derivatives. Surrounding water molecules with H-bond cooperative effects decrease the activation energy of the rate-limiting step of HE in condensed phase, especially when they lead to an anti-periplanar attack on the alkoxide leaving group. Furthermore, the water molecules have a bifunctional catalytic role in HE by (i) increasing the nucleophilic and electrophilic character of the attacking oxygen atom and the leaving group of the reaction, respectively, and (ii) placing the reactants in a suitable disposition for the substitution to occur. Overall, this investigation provides relevant insights into the collective action of water molecules on organic reactions in neutral, basic and acid media.

Should we concern about reinfection in COVID-19?: [Editorial] / ¿Deberíamos preocuparnos por la reinfección en COVID-19?: [Editorial]

After more than half year with the ongoing pandemic of the Coronavirus Disease 2019 (COVID-19) in all the continents, there are still many concerns regarding this emerging disease. The World Health Organization (WHO) declared COVID-19 as a pandemic in March 11, 2020, but it was on December 31, 2019, when a pneumonia of unknown cause was reported to WHO China Office. One of the most recent concerns about COVID-19 is the possibility of reinfection. Although experimental studies with animals suggested early in August 2020, that primary SARSCoV-2 exposure protects against subsequent reinfection in rhesus macaques, recent clinical case reports are showing that reinfection is possible.

Después de más de medio año con la pandemia en curso de la Enfermedad por Coronavirus 2019 (COVID-19) en todos los continentes, todavía hay muchas preocupaciones con respecto a esta enfermedad emergente. La Organización Mundial de la Salud (OMS) declaró la COVID-19 como pandemia el 11 de marzo de 2020, pero fue el 31 de diciembre de 2019, cuando una neumonía de causa desconocida fue notificada a la Oficina de la OMS en China. Una de las preocupaciones más recientes sobre COVID-19 es la posibilidad de reinfección. Aunque los estudios experimentales con animales sugirieron a principios de agosto de 2020, que la exposición primaria al SARSCoV-2 protege contra la reinfección posterior en macacos rhesus, los informes de casos clínicos recientes están mostrando que la reinfección es posible.

In silico modeling: electronic properties of phosphorene monoflakes and biflakes substituted with Al, Si, and S heteroatoms.

This contribution explores the systematic substitution of phosphorene monoflakes (Mfs) and biflakes (Bfs) with aluminum, silicon, and sulfur. These systems were investigated using density functional theory employing the TPSS exchange-correlation functional and complete active space self-consistent field (CASSCF) calculations. Al and Si substitution produces significant structural changes in both Mfs and Bfs compared to S-substituted and pristine systems. However, in Mfs, all heteroatoms generate a decrease in band gap and the ionization potentials (IP), and an increase in electron affinity (EA) in comparison with pristine phosphorene. Al doping improves the hole mobility in the phosphorene monoflake, while Si and S substitutions exhibit a similar behavior on EAs and reorganization energies. For Bfs, the presence of Si-Si and Al-P interlaminar interactions causes structural changes and higher binding energies for Si-Bfs and Al-Bfs. Regarding the electronic properties of Bfs, substitution with Si does not produce significant variations in the band gap. Nevertheless, it conduces the formation of hole transport materials, which does not occur in Si-Mfs. The same is observed for Al systems, whereas no correlation was identified between the doping level and reorganization energies for S complexes. The substitution with Al and S leads to an opposite behavior of the band gap and IP values, while the EA variation is similar. In summary, the nature of heteroatom and the doping degree can modify the semiconductor character and electronic properties of phosphorene mono- and biflakes, whose trends are closely related to the atomic properties considered. Overall, these computational calculations provide significant insights into the study of doped phosphorene materials.

Dengue and COVID-19, overlapping epidemics? An analysis from Colombia.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly spread throughout Latin America, a region swept by multiple previous and ongoing epidemics. There are significant concerns that the arrival of COVID-19 is currently overlapping with other viruses, particularly dengue, in various endo-epidemic regions across South America. In this report, we analyzed trends for both viral infections in Colombia during the first 20 epidemiological weeks (EWs) of 2020. From 1st January to 16th May 2020 (EWs, 1-20), a total of 52 679 cases of dengue and 14 943 cases of COVID-19 have been confirmed in Colombia. As both conditions may potentially lead to fatal outcomes, especially in patients with chronic co-morbidities, overlapping infections, and co-occurrence may increase the number of patients requiring intensive care and mechanical ventilation. In regions, such as Valle del Cauca, intensified preparation for such scenarios should be pondered, and further studies should be performed to address this critical issue in a timely matter.

On the strength of hydrogen bonding within water clusters on the coordination limit.

Hydrogen bonds (HB) are arguably the most important noncovalent interactions in chemistry. We study herein how differences in connectivity alter the strength of HBs within water clusters of different sizes. We used for this purpose the interacting quantum atoms energy partition, which allows for the quantification of HB formation energies within a molecular cluster. We could expand our previously reported hierarchy of HB strength in these systems (Phys. Chem. Chem. Phys., 2016, 18, 19557) to include tetracoordinated monomers. Surprisingly, the HBs between tetracoordinated water molecules are not the strongest HBs despite the widespread occurrence of these motifs (e.g., in ice Ih ). The strongest HBs within H2 O clusters involve tricoordinated monomers. Nonetheless, HB tetracoordination is preferred in large water clusters because (a) it reduces HB anticooperativity associated with double HB donors and acceptors and (b) it results in a larger number of favorable interactions in the system. Finally, we also discuss (a) the importance of exchange-correlation to discriminate among the different examined types of HBs within H2 O clusters, (b) the use of the above-mentioned scale to quickly assess the relative stability of different isomers of a given water cluster, and (c) how the findings of this research can be exploited to indagate about the formation of polymorphs in crystallography. Overall, we expect that this investigation will provide valuable insights into the subtle interplay of tri- and tetracoordination in HB donors and acceptors as well as the ensuing interaction energies within H2 O clusters.