Revealing the impact of organic spacers and cavity cations on quasi-2D perovskites via computational simulations

Two-dimensional hybrid lead iodide perovskites based on methylammonium (MA) cation and butylammonium (BA) organic spacer—such as BA2MAn−1PbnI3n+1—are one of the most explored 2D hybrid perovskites in recent years. Correlating the atomistic profile of these systems with their optoelectronic properties is a challenge for theoretical approaches. Here, we employed first-principles calculations via density functional theory to show how the cation partially canceled dipole moments through the NH3+ terminal impact the structural/electronic properties of the PbnI3n+1 sublattices. Even though it is known that at high temperatures, the organic cation assumes a spherical-like configuration due to the rotation of the cations inside the cage, our results discuss the correct relative orientation according to the dipole moments for ab initio simulations at 0 K, correlating well structural and electronic properties with experiments. Based on the combination of relativistic quasiparticle correction and spin-orbit coupling, we found that the MA horizontal-like configuration concerning the inorganic sublattice surface leads to the best relationship between calculated and experimental gap energy throughout n = 1, 2, 3, 4, and 5 number of layers. Conversely, the dipole moments cancellation (as in BA-MA aligned-like configuration) promotes the closing of the gap energies through an electron depletion mechanism. We found that the anisotropy → isotropy optical absorption conversion (as a bulk convergence) is achieved only for the MA horizontal-like configuration, which suggests that this configuration contribution is the majority in a scenario under temperature effects

Principais dificuldades e obstáculos enfrentados pela comunidade surda no acesso à saúde: uma revisão integrativa de literatura

RESUMO Buscou-se identificar na literatura os principais obstáculos e dificuldades enfrentadas por pessoas surdas quanto ao acesso à saúde. Trata-se de uma revisão integrativa de literatura, considerando estudos publicados entre 2006 e 2016, utilizando combinações de descritores controlados. As bases de dados virtuais utilizadas foram: LILACS, PUBMED e SciELO, incluindo artigos publicados em Inglês, Português e Espanhol. A amostra final foi composta por 24 artigos, selecionados após análise dos títulos, resumos e textos na íntegra. Os estudos selecionados foram categorizados quanto às principais temáticas e dificuldades enfrentadas pela comunidade surda, sendo principalmente relacionadas à barreira comunicacional existente entre ouvintes e surdos. Tal fato culmina em interferências na relação profissional-paciente, compreensão deficitária das pessoas surdas quanto ao processo saúde-doença e as dificuldades de integração da pessoa surda na comunidade. Na maioria dos estudos analisados, evidenciou-se que as dificuldades enfrentadas pelas pessoas surdas quando buscam atendimento em saúde são ligadas à comunicação, bem como desconhecimento de Língua Brasileira de Sinais (LIBRAS) por grande parte dos profissionais de saúde. Além disso, também há a necessidade de familiar ou intérprete presente durante a consulta e a falta de compreensão de grande parte da comunidade surda como sujeitos bilíngues e multiculturais

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data