Matéria Evaluation of zinc oxide nanoparticles influence on hydrophilic polymer matrix systems

Hydrophilic polymer matrix systems (HPMSs) are a highly relevant tool for drugs delivery whose bioavailabilityis impaired by low hydrosolubility. Besides this, when associated with nanoparticles these systems canprovide better control over release profile of the active drug, maintaining the posology. Since polyvinylpyrrolidone(PVP) and zinc oxide (ZnO) are safe materials for use in the human body, we studied the effects ofZnO nanoparticle ratios on the characteristics of PVP matrix. For that purpose, nanocomposites were preparedby solution casting method and characterized by X-ray Fluorescence (XRF), Fourier Transform Infrared(FTIR), Thermal Gravimetric Analyses (TGA), Differential Scanning Calorimetry (DSC), X-ray Diffraction(XDR) and Low-field Nuclear Magnetic Resonance (LF-NMR) technique, using relaxometry. We alsoanalyzed the effects of the system on two broad-spectrum antimicrobial drugs. The characterization results ofthe new materials indicate good interaction of the nanoparticles with the polymer, and this fact suggests thatthese new materials may have a retarding effect on drug release. The results also showed no disruptive interactionof the matrix system important to the action of the antimicrobials.Keywords: Polymer, Nanotechnology, Drug delivery, ZnO

Thermostructural evaluation of poly(butylene adipate-co-terephthalate) /molybdenum trioxide nanocomposites through time domain nuclear magnetic resonance and other conventional techniques / Avaliação termo-estrutural de nanocompósitos de poli(adipato-co-tereftalato de butileno) / trióxido de molibdénio através de ressonância magnética nuclear no domínio do tempo e outras técnicas convencionais

In present study, poly(butylene adipate-co-terephthalate) (PBAT) nanocomposites films were prepared by solvent casting technique, using chloroform (CHCl3) and containing different percentages (0-0.5 wt %) of molybdenum trioxide (MoO3) nanoparticles (NPs). The microstructure and molecular dynamics of the PBAT and PBAT/MoO3 films were characterized by X-ray diffraction (XRD) and time-domain nuclear magnetic resonance (TD-NMR). Films’ thermal degradation was studied by using thermogravimetric analysis (TGA). Fourier transform infrared spectroscopy (FTIR) confirmed: no residual solvent or contaminants and polymer matrix integrity after the casting process. The results' matchup indicated that filler–polymer interaction was suitable and, thus, MoO3NPs are potential candidates to be used as filler in PBAT matrices, especially in concentrations around 0.3 %

Produção de álcool em gel 70% com diferentes precursores poliméricos / Production of alcohol in gel 70% with different polymeric precursors

O presente estudo propõe a utilização de polímeros alternativos para a obtenção de álcool em gel 70% como ferramenta de higiene no combate ao Covid-19. Além da carboximetilcelulose, foram utilizados polímeros comerciais, descritos como derivados da celulose, Carbomex e Maxcarb, os quais apresentam propriedades gelificantes em potencial em diversas áreas. As formulações foram obtidas utilizando diferentes concentrações dos agentes gelificantes com água, glicerina e etanol. Os materiais iniciais, bem como as formulações obtidas, foram caracterizados por diferentes técnicas, incluindo Difração de Raios X, Relaxometria, Análise termogravimétrica.Os resultados das análises de Raios X indicaram uma maior cristalinidade do material obtido com Maxcarb e Carbomex quando comparados à Carboximetilcelulose. A análise termogravimétrica dos materiais indicou que o Maxcarb possui o maior valor de temperatura de degradação. Com as análises de relaxometria foi possível obter os tempos de relaxação dos materiais em solução e nos estado sólido. A Carboximetilcelulose apresentou menor valor de relaxação spin-rede quando comparado ao Maxcarb e Carbomex que apresentaram menores valores

The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

Parasitism by Amblyomma rotundatum on Teiidae lizards in the eastern part of the state of Acre, Brazil

Abstract The aim of the present study was to report on the occurrence of parasitism by Amblyomma rotundatum ticks on two species of Teiidae lizards and test the presence of rickettsiae in the collected ticks, in the western Brazilian Amazon region. Ticks were collected in July 2019, from a fragment of terra firme forest in the municipality of Senador Guiomard, Acre, Brazil. Two lizards that were infested by immature stages of ticks were caught using mist net and Tomahawk traps. Ectoparasites were collected manually, and the lizard specimens were identified and released at the same location where they had been caught. Three nymphs and 49 larvae were collected from Ameiva ameiva, while 25 nymphs and nine larvae were collected from Tupinambis cuzcoensis, which are both in the family Teiidae. The ticks were identified morphologically as belonging to the genus Amblyomma. Nymphs were identified at species level through molecular analysis, resulting in the tick species Amblyomma rotundatum. This is the first record of parasitism by the tick A. rotundatum on T. cuzcoensis lizard, and the first report of an association between A. rotundatum and the lizard species A. ameiva and T. cuzcoensis in Acre, in the western part of the Amazon region

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