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The Asteraceae family is widely known for its therapeutic, aromatic, and nutritional properties. Chaptalia nutans (C. nutans), a member of the family, is widely used in folk medicine in southern Brazil. In this study, we aim to assess compounds present in root extracts of C. nutans, and evaluate their antioxidant capacity and toxicity. To determine the chemical composition of the extract, was performed through Liquid Chromatography coupled with Mass Spectroscopy. Antioxidant capacity, toxicity (Artemia salina biosassay), cytotoxicity, genotoxicity (Allium cepa test), and neurotoxicity (Drosophila melanogaster model) were evaluated. A large number of bioactive phytoconstituents were determined to be present, such as alkaloids, coumarins, flavonoids, terpenes, and especially phenolic compounds, which may explain the antioxidant capacity of the extract. Extracts had the capacity to protect cells from protein and lipid damage, and inhibit the formation of oxygen radicals. The A. salina bioassay revealed that extracts were only slightly toxic. In A. cepa, cells exposed to 1.5 mg/mL extract were protected against chromosomal damage caused by glyphosate, and had mitotic index values that were reduced by 49%. A concentration of 10 mg/mL extract did not kill flies, and when coadministered with paraquat (PQ) (52.5%) produced a mortality rate of only 18.75%. These findings indicated that the extract had the potential to protect against PQ-induced neurotoxicity. Taken together, these data reveal for the first time that the root extract of C. nutans is a rich source of natural antioxidants. The extract may be useful in the food and pharmaceutical industries.

A Quimica e uma ciencia que busca compreender os processos naturais e nao-naturais que ocorrem no nosso meio, tornando-se importante a compreensao no que tange a alimentacao do ser humano. A intencionalidade deste estudo se faz acerca dos habitos alimentares saudaveis por estudantes do ensino medio da Educacao de Jovens e Adultos – EJA, no municipio de Alegrete/RS. A proposta se da em tres etapas: a primeira denominada de Pre-Oficina que foi realizada por meio de um questionario investigativo. A segunda foi a abordagem de conceitos de Carboidratos, Proteinas e Lipidios e sua finalizacao, por meio de uma palestra. E a terceira etapa foi a Pos-Oficina, na qual foi realizado um questionario avaliativo. Com os resultados obtidos, verificou-se que os estudantes desconheciam os conceitos “corretos” referentes ao Colesterol e que houve evolucao nas concepcoes dos estudantes acerca dos topicos estudados, bem como da tematica abordada. Desta forma, contatou-se que a intervencao promoveu a contextualizacao dos conteudos quimicos e uma proximidade com a ciencia.

The aim of this study was to evaluate the antioxidant and lipid-lowering effects of Pterodon emarginatus Vog. Oil obtained from the dried fruits by using Caenorhabditis elegans as an experimental model. Worms were exposed to different concentrations of P. emarginatus oil for 30 min. Following treatments, survival, life span, reproduction, lipid accumulation and oxidative stress endpoints were assessed. The oil composition was analyzed by GC–MS. The oil extract (0.2, 0.5, 1.0 mg/mL) increased worms longevity without affecting their reproduction. Under oxidative stress conditions, the oil provided protection against pro-oxidants, decreased reactive oxygen species production and increased antioxidant enzymes levels, thus indicating that increased survival against the pro-oxidants might be associated with the increase in antioxidant response, possibly by modulation of gene expression. Furthermore, we observed that the oil extract reduced lipid accumulation and triglycerides. We determined flavonoids and total phenolic content, which revealed a small amount of these phytochemicals. The GC–MS analysis demonstrated the presence of different components such as sesquiterpenes, which in association with flavonoids may be contributing to the antioxidant activity and to the reduction in lipid accumulation observed in C. elegans, thus indicating that this oil should be further studied as a functional food. Keywords: C. elegans, Oil extract, Lipid accumulation, Oxidative stress

The Pistia stratiotes L. was tested for phytoremediation potential of the compound clomazone in water. Clomazone is a post-emergent herbicide marketed as Gamit®. Five groups with four samples each were evaluated, a low concentration control (LCC: 37.86 mg L−1), low concentration treatment (LCT: 38.16 mg L−1), high concentration control (HCC: 54.71 mg L−1), high concentration treatment (HCT: 54.33 mg L−1), and a plant control group (PCG). Plant resistance to clomazone at determined concentrations and their ability to remove the herbicide from water by HPLC over 24 days were evaluated. The results demonstrate that P. stratiotes has high resistance to clomazone exposure and was able to eliminate up to 90% of the herbicide residues during the experimental period. Under dissipation by P. stratiotes in water, clomazone had a halflife of 19.6 days for in the control treatments, LCC and HCC, and 8.0 days in the treatment groups, LCT and HCT. This study indicates that Pistia stratiotes is an effective phytoremediation agent for the herbicide clomazone in water.

This study validated a simple, and fast method by High Performance Liquid Chromatography with Diode Array Detector (HPLC -DAD) for pesticide phytoremediation analysis. The method was developed in water and in a hydroponic medium. Sample extraction and concentration were performed by Solid Phase Extraction (SPE) with Strata C18-E type cartridges. The SPE-HPLC-DAD method was successfully applied in the detection and quantification of quinclorac, 2,4-D, propanil, bentazon, clomazone and tebuconazole in water and hydroponic medium for 14 days. The method presented excellent results with the linearity of 0.9969 - 0.9994 and the lowest limit of detection (LOD) and quantification (LOQ) of pesticides was 1.7 μg/L and 5.0 μg/L, respectively with RSD

Phytoremediation is a technique that reduces the impact and environmental toxicity of toxic agents. Plectranthus neochilus, a species of aromatic plant, has already promoted phytoremediation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). In addition, it was unclear whether the degradation of 2,4-D alone allows for a non-toxic environment (decontamination efficiency). Therefore, the aim of the present study was to verify the changes of the volatile compounds and concentrated essential oil of P. neochilus after phytoremediation of 2,4-D and the subsequent antibacterial activity of this essential oil concentrate. In addition, the toxicity of the plant’s tea and the aqueous medium (waste) after the decontamination of 2,4-D was analyzed. The exposure to 2,4-D did not cause many changes in the volatile compounds, nor in the essential oil concentrate from the plant. Therefore, this essential oil concentrate can be used as an antimicrobial after phytoremediation. Regarding the use of this plant in tea form, it was found to be unsafe, even after phytoremediation, as this tea was toxic to the Drosophila melanogaster model (death of up to 100% of flies). The aqueous medium after 2,4-D phytoremediation became less toxic than the initial one (bioassays with Artemia salina and Allium cepa in the waste groups). However, the efficiency of phytoremediation with this plant must be improved. Therefore, we are performing new studies with P. necohilus and 2,4-D in aqueous medium.

Context. Chaptalia nutans (L.) Pol. (family: Asteraceae) is widely used in traditional medicine as laxative and anticough medications and especially in the traumatisms, wounds, and hemorrhages in topical preparations. Objective. This work was to evaluate the chemical constitution of the hydromethanolic (30/70 methanol-water) macerating extract obtained from the leaves of C. nutans, as well as to study the antioxidant, antimicrobial, cytotoxic, and genotoxic activity of the species. Materials and methods. Phytochemical screening, antioxidant activity (total phenolic, total flavonoid, condensed tannins content, DPPH radical, and FRAP), antibacterial activity (P. aeruginosa, B. cereus, E. epidermidis, E. coli, S. aureus, E. faecalis, P. mirabilis, Candida glabrata (clinical isolate), Candida tropicalis (clinical isolate), C. krusei (clinical isolate), and C. albicans (clinical isolate)), and oxidative stress parameters (TBARS, carbonyl protein, and DCFH) were analyzed according to the literature. Toxicity of C. nutans was evaluated using an alternative method, D. melanogaster, as well as a locomotor assay. Results. The phytochemical screening test of methanolic leaves extract revealed the presence of alkaloids, coumarins, quaternary bases, phenolics, flavonoids, tannins, and free steroids. A quantitative phytochemical study indicated the total phenol (30.17 ± 1.44 mg/g), flavonoid (21.64 ± 0.66 mg/g), and condensed tannins (9.58 ± 0.99 mg/g). DPPH (345.41 ± 5.35 μg/mL) and FRAP (379.98 ± 39.25 μM FeSO4/mg sample) show to extract of C. nutans leaves an intermediate value, indicating moderate antioxidant activity of the extract. Antibacterial results revealed only a positive result (antimicrobial activity) for the hexane fraction which significantly inhibited the microorganisms E. epidermidis, C. tropicalis, C. glabrata, and C. krusei at a concentration of 1000 μg/mL. TBARS, carbonyl protein, and DCFH demonstrate that the extract has the ability to protect the cell from protein and lipid damage, as well as the inhibition of oxygen-derived radicals at the three concentrations tested: 0.1, 1, and 10 mg/mL. Regarding the toxicity of C. nutans extract against D. melanogaster, it was found that until the concentration of 15 mg/mL, the extract showed no toxicity and that the LC50 obtained was 24 mg/mL. Results show that the C. nutans extract leaves used to prevent PQ damage were effective in reducing flies’ mortality and improving locomotor capacity. Conclusion. Our studies demonstrated for the first time that C. nutans crude leaf extract has high antioxidant capacity both in vitro and in vivo through different analysis techniques. These results make it possible to infer future applications in the pharmacological area, evidenced by the low toxicity observed in D. melanogatser, as well as the ability to neutralize different sources of RONS.

Made available in DSpace on 2022-04-29T08:38:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The demand for the development of environmentally sustainable, low-cost and controlled-release bioinsecticides for crop protection is emerging. To that end, we have developed biodegradable zein nanoparticles (NP) loaded with clove oil (CO) or its major compound eugenol (EU), which have been widely reported by their insecticide activities. However, the safety and efficacy of these newly developed NPs is unknown. To evaluate the environmental safety of these NPs we have used the nematode Caenorhabditis elegans, a non-target organism. We observed that EU and CO NPs displayed low toxicity to these worms at all endpoints analyzed. We have evidenced a significative insectide activity of both EU and CO-loaded NPs against Drosophila melanogaster, with a higher potential in comparison to the free essential oils. These results suggest that EU and CO nanoencapsulation using zein as biopolymer is promising for further studies aiming the production of eco-friendly botanical insecticides for crop protection. Programa de Pós-Graduação em Bioquímica Grupo de pesquisa em Bioquímica e Toxicologia em Caenorhabditis elegans (GBToxCe) Universidade Federal do Pampa Universidade Estadual Paulista (UNESP) -Júlio de Mesquita Filho Instituto de Ciência e Tecnologia de Sorocaba Laboratório de Nanotecnologia Ambiental, Av. Três de Março, 511, Alto da Boa Vista Laboratório de Biofilmes e Modelos Alternativos (BioModal) Universidade Federal de Ciências da Saúde de Porto Alegre Laboratório de Estudos Físico-Químicos e de Produtos Naturais (LEFQPN) Campus Uruguaiana Universidade Federal do Pampa Universidade Estadual Paulista (UNESP) -Júlio de Mesquita Filho Instituto de Ciência e Tecnologia de Sorocaba Laboratório de Nanotecnologia Ambiental, Av. Três de Março, 511, Alto da Boa Vista FAPESP: 2015/17120-4 FAPESP: 2017/21004-5 CNPq: 453963/2014-5

The possible phytoremediation capacity of Plectranthus neochilus (boldo) exposed to the commercial pesticide (Aminol) in soil and water through consecutive extractions (days interval) was evaluated. After the exposure period, tea leaves from the plant were analyzed in terms of the presence of 2,4-D, total antioxidant capacity (DPPH), concentration of total polyphenols and flavonoids for plants exposed to soil and water. In water, 2,4-D remained up to 67% in the 60 days of experiment in the control group, which provided the use of two treatment groups with the plant (one group of plants for 30 days and another group in the remaining 30 days in the same system), thus, a decontamination up to 49% of the 2,4-D was obtained in this system with water. In both experiments (soil and water) the 2,4-D was not detected in tea leaves, the reduction of the antioxidant activity, polyphenols and flavonoids of plants exposed to the herbicide was also observed when compared to the non-exposed plants. In tea - plants in water - it was also possible to quantify the phenolic compounds and it was observed that in the group of plants of the first 30 days there was a decrease in caffeic acid and an increase in coumaric and ferulic acids, compared to the group of plants that were not exposed to 2,4-D. In the remaining 30 days with the new seedlings there was a decrease of the coumaric acid and an increase of the caffeic and ferulic acids.

Extracts from the leaves of Bougainvillea glabra Choisy are used in traditional medicines, but their actions on the central nervous system have not been studied. In the present study, we investigated the potential neuroprotective effects of Bougainvillea glabra Choisy leaf extract (BG extract) against paraquat (PQ)-induced neurotoxicity. Male adult wild-type flies (1- 4days old) were exposed to PQ (3.5mM) and/or BG extract (120μg/mL) through food for 4days. PQ-fed flies had decreased locomotor capacity in negative geotaxis and crossing number assays and had a higher incidence of mortality than the control group. PQ neurotoxicity was also associated with a marked decrease in dopamine levels and increase in acetylcholinesterase (AChE) activity, reactive oxygen species (ROS) production and lipid peroxidation. Co-exposure to BG extract prevented mortality, and dopamine depletion, improved locomotor performance and decreased AChE activity, ROS production and lipid peroxidation. GC-MS and HPLC analyses of BG extract revealed the presence of many antioxidant compounds such as phytol, α,γ-tocopherol, squalene, stigmasterol, geranylgeraniol, quercetin, and caffeic, vanillic, coumaric, ferulic acids. Our results showed neuroprotective effects of BG extract, reflecting the presence of antioxidant compounds. Thus, we suggested that B. glabra leaves could be considered an effective agent in the prevention of neurological disorders, where dopamine depletion and/or oxidative stress are involved, as in Parkinson's disease (PD).

Developed and validated a fast, simple and effective method based on the use of DLLME technique and determination by GC–MS of 26 pesticides in SE. To carry out the extraction of the pesticides of the matrix, 70 μL of mix of pesticides (1.5 μg/mL) was added to 5.0 mL of SE, containing 1.0 g of sodium chloride and 3.0 mL of acetonitrile. The results of validation were suitable. The calibration curve was linear in the range of 0.500–5.0 μg/mL. The method showed a limit of detection and quantification of 0.17 μg/mL and 0.50 μg/mL, respectively. The recovery recovering between 47% and 115%, with relative standard deviation (RSD) of

Fly fruit Drosophila melanogaster (DM) has been extensively employed as an in vivo model system to study pesticides toxicity. Pesticide administration to the fly traditionally involves feeding in an agar-gelled feed fly's medium (AM). However, AM method has several limitations such as uncertainty regarding the bioavailability and amount of pesticides ingested. And also high manipulation of the treated flies. We developed a new method of exposure the flies to pesticides, called Continuous Liquid Feeding (CLF). This method successfully delivers food to the flies at much higher concentrations than the AM method, and requires little manipulation of flies under treatment.

Handroanthus chrysotrichus is a tree of the Bignoniaceae family known as golden trumpet that is distributed throughout Northeast, Southeast and South Brazil. Its flowers, stem and bark are used for medicinal purposes in the treatment of cardiovascular and immune system diseases. This study aims to evaluate the phytochemical profile, biological activity spectrum, antioxidant capacity and toxicological potential of H. chrysotrichus stem bark extract. Hydroethanolic extract was obtained by percolation and lyophilized. Compounds present in the extract were analyzed by colorimetric methods and by GC-MS. Evaluation of the biological activity spectrum was performed in silico. Antioxidant power was determined by investigation of total antioxidant capacity, iron chelating capacity, DPPH• and ABTS•+ assays, and deoxyribose degradation test. The ability to inhibit Fe+ induced lipoperoxidation was evaluated in mouse brains and livers. Nauplii of Artemia salina were used to evaluate the median lethal dose. Toxicity was assessed by computer simulation, and in vitro in human lymphocytes. As a result, colorimetric methods suggest high levels of polyphenols and GC-MS data indicated the occurrence of α-curcumene, β-bisabolene, 4- (4-methylphenyl) pentanal, pentanoic acid and isoamyl acetate. Computer simulations have pointed biological activities that are in accordance with their traditional use. The H. chrysotrichus stem bark extract exhibited antioxidant activity in several assays and was effective in protecting mouse brains and livers from Fe+ induced lipoperoxidation. H. chrysotrichus stem bark extract showed medium toxicity in A. salina with potential presence of bioactive compounds. In general, the compounds showed low probability of toxicity in silico predictions. There was no cytotoxicity and genotoxicity in human lymphocyte evaluation. The results indicate that H. chrysotrichus stem bark extract has compounds with biological activity spectrum and low toxicological potential. It also shows antioxidant capacity and protective action against lipid peroxidation. The data presented support the medicinal use of golden trumpet and point to it as a promising extract for in vivo evaluations. Handroanthus chrysotrichus es un árbol de la familia Bignoniaceae conocido como lapacho amarillo (ipe-amarillo en Brasil) y se distribuye por todo el noreste, sudeste y sur de Brasil. Sus flores, tallo y corteza se utilizan con fines medicinales en el tratamiento de enfermedades relacionadas con el sistema cardiovascular y sistema inmune. Este estudio tiene como objetivo evaluar el perfil fitoquímico, el espectro de actividad biológica, la capacidad antioxidante y el potencial toxicológico del extracto de corteza de H. chrysotrichus. El extracto hidroetanólico se obtuvo por percolación y se liofilizó. Los compuestos presentes en el extracto se analizaron por métodos colorimétricos y GC-MS. La evaluación del espectro de actividad biológica se realizó in silico. El poder antioxidante se determinó mediante la investigación de la capacidad antioxidante total, la capacidad quelante de hierro, los ensayos DPPH• y ABTS•+, y la prueba de degradación de desoxirribosa. La capacidad de inhibir la lipoperoxidación inducida por Fe+ se evaluó en cerebros e hígados de ratones. Se utilizaron nauplios de Artemia salina para evaluar la dosis letal media (DL50). La toxicidad se evaluó mediante simulación por computadora y también in vitro en linfocitos humanos. Como resultados los métodos colorimétricos sugieren altos niveles de polifenoles y los datos de GC-MS indicaron la presencia de α-curcumeno, β-bisaboleno, ácido 4- (4-metilfenil) pentanal, ácido pentanoico y acetato de isoamilo en el extracto. Las simulaciones por computadora han señalado actividades biológicas que están de acuerdo con su uso tradicional. El extracto exhibió actividad antioxidante en varios ensayos y fue eficaz para proteger los cerebros e hígados de ratones de la lipoperoxidación inducida por Fe+. El extracto de la corteza de H. chrysotrichus mostró una toxicidad media en Artemia con posible presencia de compuestos bioactivos. En general, los compuestos mostraron baja probabilidad de toxicidad en predicciones in silico. No hubo citotoxicidad ni genotoxicidad en los ensayos con linfocitos humanos. Los resultados indican que el extracto de la corteza de H. chrysotrichus tiene compuestos con espectro de actividad biológica y bajo potencial toxicológico. También muestra capacidad antioxidante y acción protectora contra la peroxidación lipídica. Los datos presentados respaldan el uso medicinal del lapacho amarillo y lo señalan como un extracto prometedor para evaluaciones in vivo. Handroanthus chrysotrichus é uma árvore da família Bignoniaceae, conhecida como ipê-amarelo e distribui-se pelo Nordeste, Sudeste e Sul do Brasil. Suas flores, caule e casca são usadas para fins medicinais no tratamento de doenças relacionadas ao sistema cardiovascular e imunológico. Esse estudo tem por objetivos avaliar o perfil fitoquímico, espectro de atividade biológica, capacidade antioxidante e potencial toxicológico do extrato da casca de H. chrysotrichus. O extrato hidroetanólico foi obtido por percolação e liofilizado. Os compostos presentes no extrato foram analisados por métodos colorimétricos e GC-MS. A avaliação do espectro de atividade biológica foi realizada in silico. O poder antioxidante foi determinado pela investigação da capacidade antioxidante total, capacidade quelante de ferro, ensaios DPPH• e ABTS•+, e teste de degradação da desoxirribose. A capacidade de inibição da lipoperoxidação induzida por Fe+ foi avaliada em cérebros e fígados de camundongos. Náuplios de Artemia salina foram utilizados para avaliação da dose letal mediana. A toxicidade foi avaliada por simulação computacional e in vitro em linfócitos humanos. Como resultados, os métodos colorimétricos sugerem altos níveis de polifenóis e os dados de GC-MS indicaram a ocorrência de α-curcumeno, β-bisaboleno, 4- (4-metilfenil) pentanal, ácido pentanóico e acetato de isoamil no extrato da casca. Simulações computacionais apontaram atividades biológicas que estão de acordo com seu uso tradicional. A casca do extrato exibiu atividade antioxidante em diversos ensaios e foi efetiva em proteger cérebros e fígados de camundongos da lipoperoxidação induzida por Fe+. A casca de H. chrysotrichus demonstrou uma toxicidade média em A. salina com potencial presença de compostos bioativos. Em geral, os compostos apresentaram baixa probabilidade de toxicidade nas previsões in silico. Não houve citotoxicidade e genotoxicidade nos ensaios realizados com linfócitos humanos. Os resultados indicam que a casca de H. chrysotrichus possui compostos com espectro de atividade biológica e baixo potencial toxicológico. Além disso, mostra capacidade antioxidante e ação protetora contra a peroxidação lipídica. Os dados apresentados apoiam o uso medicinal do ipê-amarelo e apontam o mesmo como um extrato promissor para avaliações in vivo.

The aim of this study was to evaluate the protective effect of three different extracts prepared from Syzygium cumini leaves against paraquat-induced toxicity in Saccharomyces cerevisiae strains deficient in superoxide dismutase (SOD). Additionally, the extracts phenolic and flavonoid contents, in vitro antioxidant activity, and phytochemical composition (using high-pressure liquid chromatography) were determined. Bioactive compounds from S. cumini leaves were extracted with infusion (traditional method) or ultrasound (aqueous or hydroalcoholic). Compared to the infusion extract, the ultrasound extracts exhibited a greater protective capacity against paraquat toxicity in the yeast cells as well as higher antioxidant activity. These results may be directly related to the higher phenolic and flavonoid contents in these extracts, since they are recognized as having high antioxidant actions.

In this work, we have carried out the synthesis and thermogravimetric study of 10 different axially and peripherally substituted boron subphthalocyanines, in order to compare their thermal stabilities under non-oxidizing conditions. We demonstrate that, in general, these compounds enjoy a relatively high thermal stability, a property that is fundamental for future potential applications. The loss of the axial group is usually the first thermal degradation process to occur, and the temperature at which it takes place increases as a function of the nature of this substituent in the order: Br

Dynamic, morphological and mechanical properties of poly(ethylene terephthalate) (PET) samples, submitted to plane strain compression, were evaluated in relation to the final applied stress through stress relaxation, small angle X-ray scattering and impact resistance experiments, respectively. The stress relaxation is well described by a bimodal exponential decay, indicating a fast relaxation process with characteristic times between 2 and 8 s, and a slow one with relaxation in the range between 65 and 105 s. The SAXS experiments confirm the increase of the amorphous phase with increasing of the final applied stress. The lamellar long period tends to decrease with increasing applied stress, resulting in the stacking across the compression direction and orientation along the flow direction. The impact resistance increases with final applied stress.

A description of a specific device and a method to measure accurately large plastic deformation parameters in semicrystalline polymers induced by Plane Strain compression is presented. A force magnification of 22:1 was obtained which permitted the performance of Plane Strain Compression deformation experiments until 22 ton load. Stress values up to 300 MPa as well as strains (compression ratios) until 70% were accurately measured. Five commercial polypropylene grades with different molar mass ( M w ) namely, 161,800, 228,600, 419,800, 448,400 and 708,900 g/mol were studied. The behavior of the stress–strain curves in relation to the deformation temperature, the M w and the main features and properties obtained by Densimetry, DMA and DSC analyses of the plastically deformed polypropylene samples are presented and discussed.

Commercial isotactic poly(propylene) (iPP), obtained in bars, was annealed and submitted to different levels of plastic deformation by uniaxial plane compression using a special device which permits well controlled temperature and strain rate. The evolution of the microstructure was followed at different degrees of deformation by wide angle x-ray diffraction (WAXD) techniques. The spherulite fragmentation process, lamellar orientation and destruction of the crystallites is argued, according to collected analytical data in the flow direction (FD), the loading direction (LD) and the lateral or constrain direction (CD). The evaluation of the WAXD patterns in terms of diffraction line position, intensity and width, permits to affirm that, while the large plastic deformation occurs, the crystalline net suffers anisotropic deformation, the crystallites become preferentially oriented along the flow direction and the crystalline phase diminish in amount indicating lesser and smaller crystallites. The gradual lamellae fragmentation occurs, starting with apparent crystalline size of approximately 30 nm for the non-deformed material and gradually decreasing to approximately 15 nm for the 70% deformed one.

This study presents an experimental investigation of the large plastic deformation of poly(ethylene terephthalate) (PET) submitted to plane strain compression. PET samples, obtained by injection moulding, annealed and non-annealed, were deformed using a specific compression device developed for this purpose. The obtained stress–strain curves at different temperatures and strain rates are useful for engineering applications and show a significant temperature dependence and a minor dependence on the strain rate. A softening temperature as a minimum temperature necessary to initiate deformation when a minimum, almost zero, stress is applied is introduced. This temperature, at the zero stress and strain limit, we denominate “Stress–Strain independent softening Temperature (TSOF)”. The TSOF values, 104 and 113°C for non-annealed and annealed PET, respectively, have been obtained using three different strain rates, indicating that the property is sensitive to the thermal history of the material.

The isotatic polypropylene (i-PP) plastically deformed by uniaxial plane strain compression was investigated using X-ray diffraction and transmission electron microscopy. The apparent crystallinity was evaluated by means of X-ray diffraction with a profile matching using a FULLPROF code. Two crystalline phases, α and β, were identified in the non-deformed polymer as well as with an amorphous halo. The deformation with 3, 10 and 100 MPa, induces an increase of the amorphous halo. The microstructural orientation of the i-PP, before and after deformation was evaluated using the “Quantikov” image analysis of transmission electron microscopy (TEM) data. The non-deformed material presents spherulitic structure, without any preferential orientation. The high resolution, in the nanometer scale, shows two preferential orientation axes. The deformation at 3, 10 and 100 MPa, affects the spherulitic, as well as, the lamellae structure, introducing fiber orientation, a break up of the lamellae in to small blocks and consequently amorphization of the system.

The time–temperature dependence of the thermo-oxidative aging of polychloroprene rubber (CR) was studied using the time–temperature-transformation (TTT) superposition method and the IEC-216 norm. Aging of the material was performed inside temperature-controlled oven under circulated air temperature. The samples were characterized by gravimetry (G), thermogravimetric analysis (TG) and Shore A hardness before and after aging. It was demonstrated that the basic idea of Wisanrrakkit and Gilham for the TTT treatment of DSC thermal analysis data can be applied in the studies of CR aging processes. A quantitative relation between aging temperature, aging time, Shore A hardness and mass loss variation was demonstrated, which permits the prediction of lifetime under thermo-oxidative condition of CR.

Atualmente, os professores da educação básica encontram cada vez mais dificuldades de relacionar os conhecimentos curriculares ao cotidiano do estudante, principalmente devido ao perfil das novas gerações. O processo acelerado de conhecimento, produzido pelas novas tecnologias entra muitas vezes em conflito com a estrutura curricular das escolas. Assim, para acompanhar o desenvolvimento educacional, o professor necessita ser criativo e utilizar novas metodologias de ensino. Entre as diferentes técnicas de ensino-aprendizagem está o desenvolvimento de jogos didáticos. Neste estudo, foi feita a adaptação de um jogo aplicado ao ensino da Geografia do Mundo, a partir das regras e modelo do jogo tradicional “WAR®”. Foi construído um tabuleiro com o mapa mundi e demais materiais necessários para a aplicação do jogo, as regras são semelhantes às do jogo “WAR®”, mas adaptadas ao novo jogo. Para avaliar a aplicabilidade e eficiência deste novo método, o jogo foi aplicado em estudantes de Geografia do ensino fundamental. Foi realizada uma avaliação antes e após o desenvolvimento, a fim deve avaliar o aprendizado. O principal resultado consistiu na melhoria do aprendizado pelos estudantes. Confirma-se, portanto, que com este jogo foi desenvolvida uma nova metodologia de ensino de geografia aplicada ao ensino fundamental.

The thermal degradation of original and aged chloroprene rubber was studied using thermogravimetric analysis. Thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTG) techniques were used to detect the mass loss during the temperature elevation. By the analysis of the mass loss curves through usual kinetic methods, it was possible to evaluate the different degradation processes present in the overall degradation. The activation energies of the degradation processes were obtained using the dynamic, non-isothermal Kissinger and Osawa methods and the half-width at half-high technique (HWHH). The results obtained demonstrate clearly the differences between original and aged chloroprene rubber as well as the influence of the air and N2 in TGA.

Several nickel(II) and copper(II) complexes of triazolephthalocyanine and phthalocyanine, bearing different substituents and substitution patterns, have been synthesised and studied by standard thermogravimetric techniques in order to evaluate their thermal stability and related molecular parameters. The overall thermodegradation processes have been analysed in the partial degradation processes. The comparison of thermal stability has been made in terms of partial degradation fitting parameters: maximum degradation rate (Rmax), maximum degradation rate temperature (TRmax), degradation temperature range which is related to the half-width at half-height values (Γ); and conventional kinetic parameters: activation energy (Ea), pre-exponential factor (ln A) and reaction order (n); obtained by Barrett methods. The Ni(II) and Cu(II) phthalocyanine and triazolephthalocyanine complexes display high thermostability. The degradation processes and the corresponding maximum degradation rate temperature depend upon the complexed metal and the number, nature and position of the peripheral groups. The replacement of nickel by copper in unsubstituted metallophthalocyanines increases the degradation temperature, while the same change in triazolephthalocyanine complexes decreases this temperature. The effect of the side group and the kinetic behaviour have been studied. The compensation effect between pre-exponential factor A and activation energy Ea is confirmed.

Doripenem was characterized through physicochemical and spectroscopic techniques, as well as thermal analysis. TLC (Rf = 0.62) and HPLC (rt = 7.4 min) were found to be adequate to identify the drug. UV and infrared spectra showed similar profile between doripenem bulk and standard. The 1H and 13C NMR analysis revealed chemical shifts that allowed identifying the drug. Thermal analysis demonstrated three steps with mass loss, at 128, 178 and 276 oC. The work was successfully applied to qualitative analysis of doripenem, showing the reported methods can be used for physicochemical characterization of doripenem.

The temperature effect on the stress - strain behavior obtained during plane strain compression of poly(ethylene terephthalate) (PET) was studied using a specific device which permitted well controlled temperature, strain rate and the application of pressures up to 650 MPa. Annealed and non-annealed PET samples obtained by injection molding were studied. It is demonstrated that the Stress - Strain - Temperature (SST) superposition principle can be well applied to describe the behavior of the studied system. The thermo-mechanical history of the annealed and non-annealed materials is clearly depicted into the Stress-Strain-Temperature superposition master curves indicating transitions related to the Tg and the crystallization of the samples.