Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 43
Filtrar
Más filtros











Intervalo de año de publicación
1.
J Mol Model ; 30(4): 114, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38558272

RESUMEN

CONTEXT: Conjugated polymers (CPs) have been recognized as promising materials for the manufacture of electronic devices. However, further studies are still needed to enhance the electrical conductivity of these type of organic materials. The two main strategies for achieving this improvement are the doping process and chemical modification of the polymer chain. Therefore, in this article, we conduct a theoretical investigation, employing DFT calculations to evaluate the structural, energetic, and electronic properties of pristine and push-pull-derived poly(p-phenylene) oligomers (PPPs), as well as the analysis at the molecular level of the polymer doping process. As a primary conclusion, we determined that the PPP oligomer substituted with the push-pull group 4-EtN/CNPhNO2 exhibited the smallest HOMO-LUMO gap (Eg) among the studied oligomers. Moreover, we observed that the doping process, whether through electron removal or the introduction of the dopant anion ClO4-, led to a substantial reduction in the Eg of the PPP, indicating an enhancement in the polymer's electrical conductivity. METHODS: DFT calculations were conducted using the PBE0 functional along with the Pople's split valence 6-31G(d,p) basis set, which includes polarization functions on all atoms (B97D/6-31G(d,p)).

2.
Ciênc. Saúde Colet. (Impr.) ; Ciênc. Saúde Colet. (Impr.);29(4): e20072023, 2024.
Artículo en Portugués | LILACS-Express | LILACS | ID: biblio-1557453

RESUMEN

Resumo O sistema capitalista e cisheteropatriarcal se desenvolveu através da opressão e exploração de classe, raça e sexo no estabelecimento de relações desiguais e hierarquizadas de poder, e uma dessas opressões é o uso da violência contra os corpos considerados errantes e transgressores dentro dessa estrutura. Dentre os diversos tipos de violência, o foco deste estudo está na violência obstétrica, compreendida como uma violência patriarcal de gênero que visa a retirada de direitos, autonomia e protagonismo de mulheres e homens trans durante o período gestacional, do parto e puerpério ou em processos de abortamento. Esse artigo tem como objetivo refletir sobre a violência obstétrica e seu impacto nas homoparentalidades de mulheres lésbicas e de homens trans, pois compreende-se que a população LGBTQIA+ é uma das mais vulnerabilizadas e que está mais distante dos serviços de saúde, justamente pela violência institucional que acomete esses corpos. Dessa forma, pretende-se compreender, através de uma análise social e histórica, como os atravessamentos dessas violações sexistas e heteropatriarcais se entrelaçam e refletem na assistência à saúde dessas pessoas, gerando ainda mais formas de opressão contra essa população.


Abstract The cisheteropatriarchal capitalist system has developed by class, racial and sexual oppression and exploitation in establishing unequal, hierarchical power relations. One of these kinds of oppression involves the use of violence against bodies considered wayward and transgressive within this structure. Of the different types of violence, this study focused on obstetric violence, understood as patriarchal gender violence designed to remove the rights, autonomy and agency of trans women and men during the processes of pregnancy, childbirth, postpartum and abortion. This article reflects on obstetric violence and its impacts on homo-parenthood for lesbian women and trans men, on the understanding that the LGBTQIA+ population is one of the most vulnerable and removed from health services, mainly because of the institutional violence suffered by these bodies. Accordingly, the intention is to understand, through social and historical analysis, how these sexist, heteropatriarchal violations, interlacing and reflecting in health care for these people, generate even more forms of oppression against this population.

3.
Chemphyschem ; 24(9): e202200682, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-36720702

RESUMEN

The understanding of the molecular- and colloidal-structure of asphaltenes has seen a major progress; however, there are still issues that require answer. One of them is the location of the heteroatoms in the polycyclic aromatic hydrocarbon (PAH) fused aromatic ring (FAR) region of asphaltenes. Therefore, the effect on the frontier molecular orbitals (HOMO-LUMO) energy-gap due to the addition of a heteroatom (N or S) to PAHs, which are candidates of the PAH region in asphaltenes, has been systematically analyzed by placing S or N in various sites of the PAH molecule. The S is introduced as a thiophenic ring in a bay region, while the N is introduced as a pyridinic-N, which are prevalent forms in the asphaltene-PAH. 174 PAHs are studied with five fused aromatic rings (5FAR) to 10FAR. The π-electron allocation in resonant π-sextets and isolated double bonds is obtained using the Y-rule. The frontier orbitals optical transition is calculated with the ZINDO/S method. Within a FAR family an increment of π-sextets produces and increase of the HOMO-LUMO energy-gap. There is a linear relationship between the Y-rule mapping (percentage of fraction of π-sextet bond divided by nFAR) and the HOMO-LUMO energy-gap. In addition, the effect on the frontier orbitals energy-gap and on the π-electronic allocation due to the presence of N and S is negligible; therefore, to reach conclusions related to the asphaltene-PAH based on conclusions reached for PAH systems, with no heteroatoms, is a reasonable approach.

4.
An Acad Bras Cienc, v. 35, n. 1, e20230032, jul. 2023
Artículo en Inglés | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-4982

RESUMEN

The origins of the genus Homo have been a focus of much debate in the paleoanthropological literature due to its importance in understanding the evolutionary trajectories that led to the appearance of archaic humans and our species. On the level of taxonomic classification, the controversies surrounding the origins of Homo are the result of lack of clear classification criteria that separate our genus from australopiths, given the general similarities observed between fossils ascribed to late australopiths and early Homo. The challenge in finding clear autapomorphies for Homo has even led to debates about the classification of Homo habilis and Homo rudolfensis as part of our genus. These debates are further complicated by the scarcity of fossils in the timeframe of appearance of our genus, making any fossils dated to between 3.0 and 2.5 Ma of particular relevance in the context of this discussion. The Ledi-Geraru mandible is one such fossils, which has called the attention of researchers due to its combination of primitive traits seen in Australopithecus and derived traits observed in later Homo. Despite being fragmented and poorly preserved, it is one of the key fossil specimens available from the period mentioned above.

5.
J Mol Model ; 29(1): 2, 2022 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-36480114

RESUMEN

This research refers to the study and understanding of the conformational space of the positive-charged anthocyanidin structures in relation with the known chemical reactivities and bioactivities of these compounds. Therefore, the planar (P) and nonplanar (Z) conformers of the three hydroxylated anthocyanidins pelargonidin, cyanidin, and delphinidin were analyzed throughout the conformational space at the B3LYP/6-311 ++ G** level of theory. The outcome displayed eleven new conformers for pelargonidin, fifty-four for cyanidin, and thirty-one for delphinidin. Positive-charged quinoidal structures showed a significant statistical weight in the conformational space, thus coexisting simultaneously with other resonance structures, such that under certain reaction conditions, the anthocyanidins behave as positive-charged quinoidal structures instead of oxonium salts. The calculations of the permanent dipole moment and the polarizability showed relationships with the quantity and arrangement of hydroxyls in the structure. In addition, theoretical calculations were used to analyze the frontier molecular orbitals (HOMO-LUMO) of the three anthocyanidins. The novel conception of this work lies in the fact that dipole moment, polarizability, and HOMO-LUMO values were related to the reactivity/bioactivity of these three anthocyanidins. HOMO-LUMO energy gaps were useful to explain the antioxidant activity, while the percent atom contributions to HOMO were appropriate to demonstrate the antimutagenic activity as enzyme inhibitors, as well as the steric and electrostatic requirements to form the pharmacophore. Delphinidin was the strongest antioxidant anthocyanidin, and pelargonidin the best anthocyanidin with antimutagenic activity.


Asunto(s)
Antioxidantes , Antioxidantes/farmacología
6.
Materials (Basel) ; 15(19)2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36234076

RESUMEN

We present a systematic density functional theory study to determine the electronic structure of bending 2H-MoS2 layers up to 75° using information from in-situ nanoindentation TEM observations. The results from HOMO/LUMO and density of states plots indicate a metallic transition from the typical semiconducting phase, near Fermi energy level (EF) as a function of bending, which can mainly occur due to bending curvatures inducing a stretching and contracting of sulfur-sulfur chemical bonds located mostly over basal (001)-plane; furthermore, molybdenum ions play a major role in such transitions due to reallocation of their metallic d-character orbitals and the creation of "free electrons", possibly having an overlap between Mo-dx2-y2 and Modz2 orbitals. This research on the metallic transition of 2H-MoS2 allows us to understand the high catalytic activity for MoS2 nanostructures as extensively reported in the literature.

7.
Polit Policy ; 2022 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-35941865

RESUMEN

The COVID-19 pandemic illuminates possibilities for creating states of exception while simultaneously destabilizing the Mexico-U.S. border through the politics of fear. Specifically, the Migrant Protection Protocols (MPP), Zero Tolerance Policy (ZTP), COVID-19 CAPIO, Asylum Cooperative Agreements (ACA), and Title 42-using the pandemic under an arcane section of U.S. law to immediately expel asylum seekers and refugees, in particular-highlight the formation of a state of exception consistent with the work of Agamben. They also document how the politics of fear is used to reinforce hegemonic narratives targeting asylum seekers while attempting to reinforce political agendas that lean toward a specific brand of nationalism using the lens of public health as a context. The U.S. government under the Trump administration, and the Biden administration to a lesser extent, constructed these policies aimed primarily at refugees and asylum seekers from El Salvador, Guatemala, Honduras, and Mexico, thereby violating laws and international treaty obligations. Related Articles: Correa-Cabrera, Guadalupe. 2013. "Security, Migration, and the Economy in the Texas-Tamaulipas Border Region: The 'Real' Effects of Mexico's Drug War." Politics & Policy 41(1): 65-82. https://doi.org/10.1111/polp.12005.Duman, Yoav H. 2014. "Reducing the Fog? Immigrant Regularization and the State." Politics & Policy 42(2): 187-220. https://doi.org/10.1111/polp.12065.Garrett, Terence M. 2020. "The Security Apparatus, Federal Magistrate Courts, and Detention Centers as Simulacra: The Effects of Trump's Zero Tolerance Policy on Migrants and Refugees in the Rio Grande Valley." Politics & Policy 48(2): 372-35. https://doi.org/10.1111/polp.12348.


La pandemia de COVID­19 ilumina las posibilidades de crear estados de excepción y, al mismo tiempo, desestabilizar la relación México­Estados Unidos. frontera a través de la política del miedo. Específicamente, los Protocolos de Protección de Migrantes (MPP), la Política de Tolerancia Cero (ZTP), Covid­19 CAPIO, los Acuerdos Cooperativos de Asilo (ACA) y el Título 42: usar la pandemia bajo una sección arcana de la ley de EE. UU. para expulsar de inmediato a los solicitantes de asilo y refugiados, en particular, destaca la formación de un estado de excepción consistente con el trabajo de Agamben mientras documenta cómo la política del miedo se usa para reforzar las narrativas hegemónicas dirigidas a los solicitantes de asilo mientras intenta reforzar las agendas políticas que se inclinan hacia una marca específica de nacionalismo usando la lente de la salud pública como contexto. El gobierno de los EE. UU. bajo la administración de Trump, y la administración de Biden en menor medida, construyeron estas políticas dirigidas principalmente a refugiados y solicitantes de asilo de El Salvador, Guatemala, Honduras y México, violando así las leyes y las obligaciones de los tratados internacionales.

8.
J Anal Psychol ; 67(2): 583-592, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35856528

RESUMEN

This paper aims to understand the origins of what is seen as a lack of understanding about the seriousness of our current times. The author's view is that this failure is due to a lack of awareness that our human species is destructive, arrogant, self-centred and ignorant of the laws of nature and the wonderful complexity of the environment that it destroys. Possible new values that could support a new civilizational framework are presented.


Cet article vise à comprendre les origines de ce qui est perçu comme un manque de compréhension de la gravité de notre époque actuelle. L'auteur suggère que cet échec provient d'un déficit de conscience en ce qui concerne le fait que notre espèce humaine est destructrice, arrogante, centrée sur elle-même et ignorante des lois de la nature et de la merveilleuse complexité de l'environnement qu'elle détruit. De nouvelles valeurs envisageables - qui pourraient soutenir une nouvelle structure pour la civilisation - sont présentées.


El presente trabajo intenta comprender los orígenes de aquello que es visto como una falta de comprensión sobre la seriedad de nuestros tiempos actuales. La perspectiva del autor es que esta falla se debe a una falta de conciencia sobre la destructividad, arrogancia, auto-centración e ignorancia de nuestra especie humana acerca de las leyes de la naturaleza y la maravillosa complejidad del medio ambiente al que destruye. Se presentan nuevos valores posibles que puedan apoyar un nuevo marco de referencia para nuestra civilización.


Este artigo tem como objetivo entender as origens do que é visto como uma falta de compreensão sobre a seriedade de nossos tempos atuais. A visão do autor é que esse fracasso se deve à falta de consciência de que nossa espécie humana é destrutiva, arrogante, egocêntrica e ignorante das leis da natureza e da maravilhosa complexidade do ambiente que ela destrói. Possíveis novos valores que possam apoiar um novo quadro civilizacional são apresentados.


Asunto(s)
Trastornos Mentales , Humanos
9.
Molecules ; 27(12)2022 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-35744802

RESUMEN

Intramolecular charge transfer (ICT) effects are responsible for the photoluminescent properties of coumarins. Hence, optical properties with different applications can be obtained by ICT modulation. Herein, four 3-acetyl-2H-chromen-2-ones (1a-d) and their corresponding fluorescent hybrids 3- (phenylhydrazone)-chromen-2-ones (2a-d) were synthesized in 74-65% yields. The UV-Vis data were in the 295-428 nm range. The emission depends on the substituent in position C-7 bearing electron-donating groups. Compounds 1b-d showed good optical properties due to the D-π-A structural arrangement. In compounds 2a-d, there is a quenching effect of fluorescence in solution. However, in the solid, an increase is shown due to an aggregation-induced emission (AIE) effect given by the rotational restraints and stacking in the crystal. Computational calculations of the HOMO-LUMO orbitals indicate high absorbance and emission values of the molecules, and gap values represent the bathochromic effect and the electronic efficiency of the compounds. Compounds 1a-d and 2a-d are good candidates for optical applications, such as OLEDs, organic solar cells, or fluorescence markers.


Asunto(s)
Cumarinas , Electrones , Cumarinas/química , Teoría Funcional de la Densidad , Espectrometría de Fluorescencia
10.
Biochim Biophys Acta Proteins Proteom ; 1869(12): 140719, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34571256

RESUMEN

Human 71 kDa heat shock cognate protein (HSPA8, also known as Hsc70, Hsp70-8, Hsc71, Hsp71 or Hsp73) is a constitutively expressed chaperone that is critical for cell proteostasis. In the cytosol, HSPA8 plays a pivotal role in folding and refolding, facilitates protein trafficking across membranes and targets proteins for degradation, among other functions. Here, we report an in solution study of recombinant HSPA8 (rHSPA8) using a variety of biophysical and biochemical approaches. rHSPA8 shares several structural and functional similarities with others human Hsp70s. It has two domains with different stabilities and interacts with adenosine nucleotides with dissociation constants in the low micromolar range, which were higher in the presence of Mg2+. rHSPA8 showed lower ATPase activity than its homolog HSPA5/hGrp78/hBiP, but it was 4-fold greater than that of recombinant HSPA1A/hHsp70-1A, with which it is 86% identical. Small angle X-ray scattering indicated that rHSPA8 behaved as an elongated monomeric protein in solution with dimensions similar to those observed for HSPA1A. In addition, rHSPA8 showed structural flexibility between its compacted and extended conformations. The data also indicated that HSPA8 has capacity in preventing the aggregation of model client proteins. The present study expands the understanding of the structure and activity of this chaperone and aligns with the idea that human homologous Hsp70s have divergent functions.


Asunto(s)
Proteínas del Choque Térmico HSC70/química , Adenosina Trifosfato/química , Adenosina Trifosfato/metabolismo , Proteínas del Choque Térmico HSC70/metabolismo , Humanos , Magnesio/química , Magnesio/metabolismo , Simulación de Dinámica Molecular , Dominios Proteicos , Pliegue de Proteína
11.
ACS Sens ; 6(7): 2642-2653, 2021 07 23.
Artículo en Inglés | MEDLINE | ID: mdl-34191492

RESUMEN

Understanding signal propagation across biological networks requires to simultaneously monitor the dynamics of several nodes to uncover correlations masked by inherent intercellular variability. To monitor the enzymatic activity of more than two components over short time scales has proven challenging. Exploiting the narrow spectral width of homo-FRET-based biosensors, up to three activities can be imaged through fluorescence polarization anisotropy microscopy. We introduce Caspase Activity Sensor by Polarization Anisotropy Multiplexing (CASPAM) a single-plasmid triple-modality reporter of key nodes of the apoptotic network. Apoptosis provides an ideal molecular framework to study interactions between its three composing pathways (intrinsic, extrinsic, and effector). We characterized the biosensor performance and demonstrated the advantages that equimolar expression has in both simplifying experimental procedure and reducing observable variation, thus enabling robust data-driven modeling. Tools like CASPAM become essential to analyze molecular pathways where multiple nodes need to be simultaneously monitored.


Asunto(s)
Técnicas Biosensibles , Transferencia Resonante de Energía de Fluorescencia , Anisotropía , Caspasas/genética , Microscopía Fluorescente
12.
Evol Anthropol ; 30(2): 122-127, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32893976

RESUMEN

Recent discoveries of stone tools from Jordan (2.5 Ma) and China (2.1 Ma) document hominin presence in Asia at the beginning of the Pleistocene, well before the conventional Dmanisi datum at 1.8 Ma. Although no fossil hominins documenting this earliest Out of Africa phase have been found, on chronological grounds a pre-Homo erectus hominin must be considered the most likely maker of those artifacts. If so, this sheds new light on at least two disputed subjects in paleoanthropology, namely the remarkable variation among the five Dmanisi skulls, and the ancestry of Homo floresiensis.


Asunto(s)
Migración Animal , Hominidae/fisiología , África , Animales , Asia , Europa (Continente) , Historia Antigua , Paleontología , Comportamiento del Uso de la Herramienta/fisiología
13.
Front Cell Infect Microbiol ; 10: 591121, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33251160

RESUMEN

Histoplasmosis is one of the most frequent systemic mycosis in HIV patients. In these patients, histoplasmosis has high rates of morbidity/mortality if diagnosis and treatment are delayed. Despite its relevance, there is a paucity of information concerning the interaction between Histoplasma capsulatum and the human host, especially regarding the B-cell response, which has a direct impact on the diagnosis. Culture-based "gold-standard" methods have limitations, making immunodiagnostic tests an attractive option for clinical decisions. Despite the continuous development of those tests, improving serological parameters is necessary to make these methods efficient tools for definitive diagnosis of histoplasmosis. This includes the determination of more specific and immunogenic antigens to improve specificity and sensitivity of assays. In this study, we performed a co-immunoprecipitation assay between a protein extract from the yeast form of H. capsulatum and pooled sera from patients with proven histoplasmosis, followed by shotgun mass spectrometry identification of antigenic targets. Sera from patients with other pulmonary infections or from healthy individuals living in endemic areas of histoplasmosis were also assayed to determine potentially cross-reactive proteins. The primary structures of H. capsulatum immunoprecipitated proteins were evaluated using the DNAStar Protean 7.0 software. In parallel, the online epitope prediction server, BCPREDS, was used to complement the B-epitope prediction analysis. Our approach detected 132 reactive proteins to antibodies present in histoplasmosis patients' sera. Among these antigens, 127 were recognized also by antibodies in heterologous patients' and/or normal healthy donors' sera. Therefore, the only three antigens specifically recognized by antibodies of histoplasmosis patients were mapped as potential antigenic targets: the M antigen, previously demonstrated in the diagnosis of histoplasmosis, and the catalase P and YPS-3 proteins, characterized as virulence factors of H. capsulatum, with antigenic properties still unclear. The other two proteins were fragments of the YPS-3 and M antigen. Overlapping results obtained from the two aforementioned bioinformatic tools, 16 regions from these three proteins are proposed as putative B-cell epitopes exclusive to H. capsulatum. These data reveal a new role for these proteins on H. capsulatum interactions with the immune system and indicate their possible use in new methods for the diagnosis of histoplasmosis.


Asunto(s)
Infecciones por VIH , Histoplasmosis , Antígenos Fúngicos , Epítopos de Linfocito B , Histoplasma , Histoplasmosis/diagnóstico , Humanos
14.
Motrivivência (Florianópolis) ; 32(63): [1-20], Jul. 2020.
Artículo en Portugués | LILACS-Express | LILACS | ID: biblio-1118727

RESUMEN

O presente artigo teve como vocação verificar se o tema homossexualidade é problematizado nas aulas de Educação Física e qual o trabalho desenvolvido pelo professor de Educação Física frente aos alunos homoafetivos. Para tanto, nos apropriamos dos pressupostos teóricos e metodológicos da pesquisa qualitativa do tipo descritiva. Utilizamos a entrevista semiestruturada, que foi realizada com 10 (dez) professores de Educação Física, os quais desenvolvem suas atividades docentes em escolas públicas estaduais da cidade de Teresina ­ PI. Os dados coletados foram submetidos à análise temática de conteúdos proposta por Bardin, com a finalidade de sintetização de categorias de análises. Da análise das falas dos depoentes, foi possível extrair quatro categorias de análise: O homoafetivo invisível nas aulas de Educação Física; A homoafetividade como discurso da recusa; A igualdade que descaracteriza o homoafetivo nas aulas de Educação Física e As escolas de muitos e as aulas de alguns poucos. Encontramos, nas escolas, educadores que se dizem (e se sentem) compromissados com o seu fazer profissional, mas mostram-se cegos para as suas ações, principalmente quando questionados sobre as ações didáticas pedagógicas estabelecidas na quadra de aula junto aos alunos homoafetivos. Portanto, conclui-se a não existência de tratos pedagógicos nas aulas de Educação Física para as atividades corporais referentes à questão da homoafetividade, mesmo com todos os professores verbalizarem ser cientes da presença do homoafetivo em suas aulas. Ao contrário, o que ficou evidente foi um discurso da igualdade que descaracteriza o aluno homoafetivo no decorrer das aulas.


The present article had the vocation to verify if the homosexuality theme is problematized in Physical Education classes and what is the work developed by the Physical Education teacher in front of homo-affective students. Therefore, we appropriate the theoretical and methodological assumptions of qualitative research of the descriptive type. We used the semi-structured interview, which was carried out with 10 (ten) Physical Education teachers, who develop their teaching activities in state public schools in the city of Teresina - PI. The collected data were submitted to the thematic content analysis proposed by Bardin, in order to synthesize categories of analysis. From the analysis of the statements of the interviewees, it was possible to extract four categories of analysis: The invisible homoaffective in Physical Education classes; Homo-affection as a discourse of refusal; The equality that mischaracterizes the homoaffective in Physical Education classes and the schools of many and the classes of a few. In schools, we find educators who say (and feel) committed to their professional practice, but are blind to their actions, especially when asked about the pedagogical didactic actions established in the classroom with homo-affective students. Therefore, it is concluded that there is no pedagogical treatment in Physical Education classes for body activities related to the issue of homoaffection, even with all teachers verbalizing being aware of the presence of homoaffective in their classes. On the contrary, what was evident was a discourse of equality that mischaracterizes the homoaffective student during the classes.


El presente artículo tenía la vocación de verificar si el tema de la homosexualidad se problematiza en las clases de Educación Física y cuál es el trabajo desarrollado por el maestro de Educación Física frente a los estudiantes homo-afectivos. Para eso, nos apropiamos de los supuestos teóricos y metodológicos de la investigación cualitativa del tipo descriptivo. Utilizamos la entrevista semiestructurada, que se realizó con 10 (diez) maestros de Educación Física, que desarrollan sus actividades de enseñanza en las escuelas públicas estatales de la ciudad de Teresina - PI. Los datos recopilados se sometieron al análisis de contenido temático propuesto por Bardin, con el fin de sintetizar categorías de análisis. A partir del análisis de las declaraciones de los entrevistados, fue posible extraer cuatro categorías de análisis: el homoafectivo invisible en las clases de educación física; El afecto como discurso de rechazo; Igualdad que caracteriza erróneamente la eficacia de las clases de educación física y las escuelas de muchos y las clases de unos pocos. En las escuelas, encontramos educadores que dicen (y se sienten) comprometidos con su práctica profesional, pero que son ciegos a sus acciones, especialmente cuando se les pregunta sobre las acciones didácticas pedagógicas establecidas en el aula con estudiantes homo-afectivos. Por lo tanto, se concluye que no existe un tratamiento pedagógico en las clases de Educación Física para las actividades corporales relacionadas con el tema de la homosexualidad, incluso cuando todos los maestros verbalizan estar conscientes de la presencia de homoafectivos en sus clases. Por el contrario, lo que era evidente era un discurso de igualdad que caracteriza erróneamente al estudiante efectivo durante las clases.

15.
Sci Total Environ ; 702: 134966, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-31733560

RESUMEN

OBJECTIVES: Human progress is the satisfaction of human needs associated with life quality, social and economic justice. Considering that climate had significant effect on socio-economic behavior of Earth populations, the objective of this work was to evaluate the relationship between human progress and drought sensitivity behavior in Minas Gerais State, Brazil. METHODS: The human progress variable was generated by principal component analysis, considering the factors: Territorial occupation of the population, dependency ratio, urbanization degree, income, habitation, health, education, sanitation, security and human development index. The moisture index product was generated based on map algebra calculation in GIS, using WorldClim precipitation and MODIS evapotranspiration products. Nonlinear least squares method and Levenberg-Marquardt algorithm fit an exponential model to the moisture index (independent) and human progress (dependent) variables. Covariance and crossed-covariance functions were used to characterize the structure and magnitude of spatial dependence between the human progress and the moisture index co-variable. RESULTS: Couple modeling human progress and moisture index variability generated the human drought sensitivity behavior variable, representing the effects of regional climate in Homo sapiens population. The generated human drought sensitivity behavior values were inverted, i.e. lower and higher human drought sensitivity behavior values indicated higher and lower human sensitivity to drought, respectively. Adaptive management capacity with more capable governments combining economic and engineering solutions to maximize species, habitat, ecosystem survival and resilience, could generate best mitigation solutions to reduce potential impacts of climatic spatial variation in Minas Gerais state, Brazil.


Asunto(s)
Sequías , Desarrollo Económico , Ecosistema , Brasil , Clima , Humanos , Agua
16.
Biol Lett ; 15(10): 20190481, 2019 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-31594495

RESUMEN

According to the island rule, small-bodied vertebrates will tend to evolve larger body size on islands, whereas the opposite happens to large-bodied species. This controversial pattern has been studied at the macroecological and biogeographical scales, but new developments in quantitative evolutionary genetics now allow studying the island rule from a mechanistic perspective. Here, we develop a simulation approach based on an individual-based model to model body size change on islands as a progressive adaptation to a moving optimum, determined by density-dependent population dynamics. We applied the model to evaluate body size differentiation in the pigmy extinct hominin Homo floresiensis, showing that dwarfing may have occurred in only about 360 generations (95% CI ranging from 150 to 675 generations). This result agrees with reports suggesting rapid dwarfing of large mammals on islands, as well as with the recent discovery that small-sized hominins lived in Flores as early as 700 kyr ago. Our simulations illustrate the power of analysing ecological and evolutionary patterns from an explicit quantitative genetics perspective.


Asunto(s)
Hominidae , Animales , Evolución Biológica , Tamaño Corporal , Fósiles , Indonesia , Islas , Mamíferos
17.
Rev. colomb. quím. (Bogotá) ; 48(2): 40-45, mayo-ago. 2019. tab, graf
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1013968

RESUMEN

Resumen Desde el punto de vista científico y tecnológico ha habido un gran interés en el uso de monosustituyentes de furano y tiofeno como polímeros conductores, debido a sus múltiples aplicaciones como OLED, amplificadores ópticos, nanotecnología, entre otros. Por ello, el propósito de este trabajo fue estudiar los aspectos teóricos que afectan las propiedades electroconductoras de este tipo de moléculas. Se determinaron teóricamente los aspectos estructurales y electrónicos que influyeron en la conductividad de copolímeros de furano-tiofeno monosustituidos, al utilizar grupos carboxilos, metilos, hidroxilos, ciano y fluoruros como sustituyentes en el carbono C3 y C10 de cada heterociclo. La diferencia de energía entre el LUMO y el HOMO (band gap, Eg) y el potencial de ionización (PI) fue calculada a partir de las geometrías optimizadas en DFT para el estado neutro, anión y catión. Los PI y la Eg de los copolímeros fueron obtenidos mediante la extrapolación de los valores del oligómero a (1/N) y de una cadena de longitud infinita (1/N=0), obteniéndose una correlación lineal (R=0,99), la cual se mantiene a lo largo de todos los modelos de ajuste de cada copolímero analizado en el estudio.


Abstract There has been great scientific and technological interest in the use of mono-substituents of furan and thiophene as conducting polymers due to their multiple applications such as OLED, optical amplifiers and nanotechnology, among others. For this, the purpose of this work was to study the theoretical aspects that affect the electroconductive properties of this type of molecules. The structural and electronic properties that influence the conductivity of mono substituted-furan-thiophene copolymers were determined theoretically. The effect of using carboxyl, methyl, hydroxyl, cyano, and fluoride groups as substituents on the carbon C3 and C10 of each heterocycle was observed. The energy difference between the LUMO and the HOMO (band gap, Eg) and the ionization potential (IP) were calculated from the geometries optimized in DFT for the neutral, anion and cation state. The PI and Eg of the copolymers were obtained by extrapolating the values of the oligomer a (1/N) and a chain of infinite length (1/N=0) for which a linear correlation was obtained (R=0.99). This correlation is maintained throughout all the adjustment models of each copolymer analyzed in the study.


Resumo Existe muito interesse os termos científicos e tecnológicos em utilizar substituintes mono-substituídos furano e tiofeno como polímeros condutores devido às suas múltiplas aplicações, tais como OLED, amplificadores ópticos e nanotecnologia, entre outros. O objetivo deste trabalho foi estudar os aspectos teóricos que afetam as propriedades eletrocondutoras deste tipo de moléculas. Neste contribuição os aspectos estruturais e electrónicas que influenciam a condutividade de copolímeros furano-tiofeno substituos mono teoricamente determinada observando o efeito do uso de grupos carboxilo, metilo, hidroxilo, ciano e fluoretos como substituintes em C3 e C10 de carbono de cada heterociclo. A diferença de energia entre o LUMO e o HOMO (intervalo de banda, Eg) e o potencial de ionização (IP) foram calculadas a partir das geometrias optimizadas de DFT para o estado neutro, anião e catião. O PI e o Eg dos copolímeros foram obtidos por extrapolação dos valores do oligómero (1/N) e extrapolando para uma cadeia de comprimento infinito (1/ N=0) para os quais uma correlação linear foi obtida (R=0,99), que é mantido ao longo de todos os modelos de ajuste de cada copolímero analisados no estudo.

18.
Funct Integr Genomics ; 19(5): 787-797, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31089837

RESUMEN

Septins are GTP-binding proteins that polymerize to form filaments involved in several important biological processes. In human, 13 distinct septins genes are classified in four groups. Filaments formed by septins are complex and usually involve members of each group in specific positions. Expression data from GTEx database, a publicly available expression database with thousands of samples derived from multiple human tissues, was used to evaluate the expression of septins. The brain is noticeably a hotspot for septin expression where few genes contribute to a large portion of septin transcript pool. Co-expression data between septins suggests two predominant specific complexes in brain tissues and one filament in other tissues. SEPT3 and SEPT5 are two genes highly expressed in the brain and with a strong co-expression in all brain tissues. Additional analysis shows that the expression of these two genes is highly variable between individuals, but significantly dependent on the individual's age. Age-dependent decrease of expression from those two septins involved in synapses reinforces their possible link with cognitive decay and neurodegenerative diseases associated with aging. Analysis of enrichment of Gene Ontology terms from lists of genes consistently co-expressed with septins suggests participation in diverse biological processes, pointing out some novel roles for septins. Interestingly, we observed strong consistency of some of these terms with experimentally described roles of septins. Coordination of septins expression with genes involved in DNA repair and cell cycle control may provide insights for previously described links between septins and cancer.


Asunto(s)
Regulación de la Expresión Génica , Septinas/clasificación , Septinas/metabolismo , Adulto , Factores de Edad , Anciano , Humanos , Persona de Mediana Edad , Septinas/genética , Distribución Tisular , Adulto Joven
19.
Bioorg Med Chem ; 27(12): 2579-2591, 2019 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-30935792

RESUMEN

Achyrocline satureioides (Lam) D.C (Compositae) is a native medicinal plant of South America traditionally utilized for its anti-inflammatory, sedative and anti-atherosclerotic properties among others. Neuroprotective effects have been reported in vivo and could be associated to its elevated content of flavonoid aglycones. In the present study we performed the isolation and structure elucidation of the major individual flavonoids of A. satureioides along with the in vitro characterization of their individual antioxidant and neuroprotective properties in order to see their putative relevance for treating neurodegeneration. Exact mass, HPLC-MS/MS and 1H NMR identified dicaffeoyl quinic acid isomers, quercetin, luteolin, isoquercitrin, and 3-O-methylquercetin as the mayor polyphenols. Flavonoids intrinsic redox properties were evaluated in the presence of the endogenous antioxidants GSH and Ascorbate. Density Functional Theory (DFT) molecular modeling and electron density studies showed a theoretical basis for their different redox properties. Finally, in vitro neuroprotective effect of each isolated flavonoid was evaluated against hydrogen peroxide-induced toxicity in a primary neuronal culture paradigm. Our results showed that quercetin was more efficacious than luteolin and isoquercitrin, while 3-O-methylquercetin was unable to afford neuroprotection significantly. This was in accordance with the susceptibility of each flavonoid to be oxidized and to react with GSH. Overall our results shed light on chemical and molecular mechanisms underlying bioactive actions of A. satureioides main flavonoids that could contribute to its neuroprotective effects and support the positive association between the consumption of A. satureioides as a natural dietary source of polyphenols, and beneficial health effect.


Asunto(s)
Achyrocline/química , Antioxidantes/química , Polifenoles/química , Sustancias Protectoras/química , Achyrocline/metabolismo , Animales , Cromatografía Líquida de Alta Presión , Teoría Funcional de la Densidad , Flavonoides/química , Flavonoides/aislamiento & purificación , Modelos Moleculares , Conformación Molecular , Neuronas/citología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Extractos Vegetales/química , Plantas Medicinales/química , Plantas Medicinales/metabolismo , Polifenoles/aislamiento & purificación , Polifenoles/farmacología , Sustancias Protectoras/aislamiento & purificación , Sustancias Protectoras/farmacología , Ratas , Ratas Sprague-Dawley , Espectrometría de Masas en Tándem
20.
Environ Sci Pollut Res Int ; 26(7): 6532-6544, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30623335

RESUMEN

A solar homo/heterogeneous photo-Fenton process using five materials (Fe(II), Fe(III), mining waste, Fe(II)/mining waste, and Fe(III)/mining waste) supported on sodium alginate was used as a strategy to iron dosage for the degradation of eight pharmaceuticals in three different water matrices (distilled water, simulated wastewater, and hospital wastewater). Experiments were carried out in a photoreactor with a capacity of 1 L, using 3 g of iron-alginate spheres and an initial hydrogen peroxide concentration of 25 mg L-1, at pH 5.0. All the materials prepared were characterized by different techniques. The Fe(III)-alginate spheres presented the best pharmaceutical degradation after a treatment time of 116 min. Nineteen transformation products generated during the solar photo-Fenton process were identified by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry, using a purpose-built database developed for detecting these transformation products. Finally, the transformation products identified were classified according to their toxicity and predicted biodegradability.


Asunto(s)
Preparaciones Farmacéuticas/análisis , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/análisis , Alginatos , Biodegradación Ambiental , Cromatografía Liquida , Compuestos Férricos , Peróxido de Hidrógeno , Hierro , Preparaciones Farmacéuticas/química , Luz Solar , Aguas Residuales , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA