Synthesis and characterization of copolymers of alkyl- and azo-thiophenes: chromic properties and photoinduced birefringence

Polyazothiophene is a type of polythiophene derivative that combines the electrical and luminescent properties of polythiophenes with the photoisomerization property of azopolymers. Extensive efforts have been made to improve the properties of polyazothiophenes, such as solubility, optical, and chromic properties. We report the preparation of copolymers of an alkylthiophene (3-octylthiophene, 3-OT) and an azothiophene (2-[N-ethyl-N-[4-[(4-(4-nitrophenyl)azo]phenyl]amino]ethyl 3-thienylacetate, 3-AzoT) in different ratios as an alternative route to improve these properties. The azosubstituted monomer contents in these copolymers were 6, 9, 12, and 51% (in mol), as evaluated by elemental analysis. Their chemical structures were confirmed by FTIR and 1H-NMR. HPSEC and thermal analysis were used to characterize the polymers. The presence of thermochromic and solvatochromic properties was demonstrated by UV-Vis spectroscopy. Optically induced birefringence was detected only in polymers with 12 and 51 mol % of azo-units. The introduction of different ratios of the azothiophene in the copolymer alters the polymer solubility and emissive properties. The results indicate that the polyazothiophene copolymers presented are promising active layers for optical devices and sensor

Ocorrência de microrganismos em ração animal preparada artesanalmente a partir do licuri (Syagrus coronata)

During the dry season in the Brazilian Caatinga region when sources of food are very scanty, many farmers use alternative forms to feed their livestock. One of these alternative forms is the feed made with the fruits of licuri palm (Syagrus coronata), produced by hand by farmers or associations without any microbial control, until the present study. The control of the microbial growth in feeds, used in the animal feeding, aims mainly to decrease risks in the health of the meat consumers, by increasing sanitation and hygienic quality of the feed. Therefore, this work aimed to carry out a microbiological analysis (presence of salmonela, counting of mesophilic microorganisms, and contamination by filamentous fungi and yeasts) of the ration of licuri prepared by an association of agricultural producers from the town of Valente, Bahia. The microbiological quality in the analyzed samples was good in accordance with standardized microbiological norms from The Netherlands, without salmonela, low counting of mesophilic microorganisms, and low contamination by filamentous fungi and yeasts in all analyses that were conducted. This is the first work published that describes the microbiological quality of the licuri feed produced by hand.Durante a época de seca na região da Caatinga brasileira, quando a oferta de alimento é escassa, muitos produtores utilizam formas alternativas para alimentar seu rebanho. Uma delas é a ração à base de frutos de licurizeiro (Syagrus coronata), processada artesanalmente pelos próprios produtores rurais ou associações, sem nenhum controle microbiano, feito até o presente estudo. O controle do desenvolvimento microbiano em rações utilizadas na alimentação animal visa principalmente diminuir os riscos à saúde dos consumidores de carnes, melhorando a qualidade higiênica e sanitária da ração. Por isso, este trabalho objetivou a análise microbiológica (presença de salmonelas, contagem de microsganismos mesófilos e contaminação por fungos e leveduras) da ração à base de licuri preparada por uma associação de produtores rurais do município de Valente, Bahia. A qualidade microbiológica encontrada nas amostras analisadas foi boa quando comparada com as normas microbiológicas para ração padronizadas da Holanda, ocorrendo ausência de salmonelas, baixa contagem de microrganismos mesófilos e baixa contaminação por fungos filamentosos e leveduras em todas as análises realizadas. Este é o primeiro trabalho na literatura que descreve a qualidade microbiológica da ração à base de licuri produzida artesanalmente

A database of freshwater fish species of the Amazon Basin

The Amazon Basin is an unquestionable biodiversity hotspot, containing the highest freshwater biodiversity on earth and facing off a recent increase in anthropogenic threats. The current knowledge on the spatial distribution of the freshwater fish species is greatly deficient in this basin, preventing a comprehensive understanding of this hyper-diverse ecosystem as a whole. Filling this gap was the priority of a transnational collaborative project, i.e. the AmazonFish project - https://www.amazon-fish.com/. Relying on the outputs of this project, we provide the most complete fish species distribution records covering the whole Amazon drainage. The database, including 2,406 validated freshwater native fish species, 232,936 georeferenced records, results from an extensive survey of species distribution including 590 different sources (e.g. published articles, grey literature, online biodiversity databases and scientific collections from museums and universities worldwide) and field expeditions conducted during the project. This database, delivered at both georeferenced localities (21,500 localities) and sub-drainages grains (144 units), represents a highly valuable source of information for further studies on freshwater fish biodiversity, biogeography and conservation