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Avaliação da segurança e estudo da permeação e retenção cutânea de géis de ácido hialurônico /Martini, Paula Cressoni. January 2011 (has links)
Orientador: Vera Lucia Borges Isaac / Coorientador: Marcos Antonio Corrêa / Banca: Hérida Regina Nunes Salgado / Banca: André Rolim Baby / Resumo: O aumento da expectativa de vida tem provocado grande demanda por produtos que auxiliem na prevenção do envelhecimento da pele. O ácido hialurônico (AH) está sendo muito utilizado em formulações antienvelhecimento por se acreditar que ele possa atenuar os efeitos que o tempo produz na pele. Porém, para o desenvolvimento de um cosmético, é necessário avaliar o risco potencial dos ingredientes que compõem a formulação, que devem estar em concentração que apresente margem de segurança adequada, sendo importante a realização de teste de absorção, estudo do potencial de risco irritativo e testes de mutagenicidade. O objetivo deste estudo foi desenvolver um gel de ácido hialurônico com alta massa molecular e incorporar ácido hialurônico de massas moleculares menores, realizar o controle microbiológico dos géis, avaliar a toxicidade dérmica aguda e a citotoxicidade, determinar o comportamento reológico das formulações, analisar seu perfil de liberação, permeação e retenção cutânea in vitro. Foi preparado como gel base, a mistura de água e AH de alta massa molecular e, posteriormente, neste gel formado foram incorporados os AHs de menores massas moleculares. O controle de qualidade microbiológico foi realizado de acordo com a Farmacopeia Brasileira (2010), a avaliação da toxicidade dérmica aguda foi realizada utilizando-se 25 ratos wistar, que foram divididos em 5 grupos com 5 animais em que cada grupo recebeu a aplicação de um dos géis para posterior analise dos resultados. Para a avaliação da citotoxicidade utilizou-se o método colorimétrico 3-(4,5-dimetiltiazol-2-il)2,5-difenil brometo de tetrazoilium (MTT) descrito por MOSMANN, utilizando-se linhagens celulares de HepG2 (Human Epidermoide Cancer Cells) e HaCaT. As amostras tiveram seu comportamento reológico avaliado em reômetro HAAKE. O estudo de liberação, permeação e retenção cutânea... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Increased life expectancy has caused a great demand for products that help in the prevention of skin aging. Hyaluronic acid is being used in anti-aging formulations because it is expected that it can decrease the effects of time in the skin. However, for the development of a cosmetic it is necessary to evaluate the potential risk of the ingredients in the formulation that should be with adequate concentration to provide a margin of safety, being important to carry out absorption test, studies of the potential risk of irritating the skin and mutagenicity tests. The aim of this study was to develop a gel of hyaluronic acid with high molecular weight and incorporate hyaluronic acid with small molecular weights in it, analyze the microbiological control of the gels, evaluate the acute dermal toxicity and cytotoxicity, determine rheological characteristics, analyze the release profile, skin permeation and retention in vitro. It was prepared like gel base, the mixture of water and AH of high molecular weight, and after was incorporate AH of smaller molecular weight. The quality control microbiological was accomplished in agreement with Brazilian Pharmacopoeia (2010), the evaluate the acute dermal toxicity was made with 25 rat wistar, that were divided in 5 groups with 5 animals in each group received the application from one of the gels for subsequent analyzes of the results. For the evaluation of the cytotoxicity was used the method colorimeter 3-(4,5-dimetiltiazol-2-il)2,5-difenil tetrazoilium bromide (MTT) described by MOSMANN (1983), being used cellular lineages of HepG2 (Human Epidermoide Câncer Cells) and HaCaT. The samples had its behavior rheological characteristics. The analyze the release profile, skin permeation and retention were accomplished using cells of Franz modified. The microbiological was in agreement... (Complete abstract click electronic access below) / Mestre
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Avaliação da atividade antifúngica e citotoxicidade de microcristais de alfa vanadato de prata (α-AgVO3) sintetizados em diferentes temperaturas /Pimentel, Bruna Natália Alves da Silva January 2017 (has links)
Orientador: Carlos Eduardo Vergani / Resumo: Nos últimos anos, os microcristais de prata têm se tornado foco de estudos. Uma das propriedades evidenciadas destes materiais é a sua atividade antimicrobiana contra diferentes microrganismos, devido a presença da prata na sua composição. Neste estudo, investigou-se a atividade antifúngica de microcristais de alfa vanadato de prata (α-AgVO3) contra Candida albicans (ATCC 90028) e sua citotoxicidade sobre células do tipo queratinócitos orais normais espontaneamente imortalizados (NOK-si). Os microcristias de α-AgVO3 foram sintetizados pelo método da co-precipitação sob três diferentes temperaturas (10, 20 e 30ºC) e caracterizados através de difração de raios-x, microscopia eletrônica de varredura por emissão de campo e espectroscopia Raman. A atividade antifúngica foi avaliada a partir da microdiluição seriada dos microcristais (de acordo com o Clinical & Laboratorial Standards Institute - CLSI), onde foram determinadas as concentrações inibitória (CIM) e fungicida mínimas (CFM). Imagens de microscopia de fluorescência com os microcristais nas concentrações inibitória e fungicida mínimas foram obtidas a fim de confirmar os achados microbiológicos. A viabilidade celular de células NOK-si foi avaliada através do ensaio Alamar Blue, e imagens de microscopia eletrônica de varredura (MEV) de todos os grupos avaliados foram realizadas. Nos ensaios celulares foram utilizadas apenas quatro concentrações dos microcristais (CIM, CFM, CIM diluída 10 vezes e concentrada 10 vezes). Os r... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
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Lethal and Sublethal Effects of Hemoxidants, Particularly Nitrite, on Selected Aquatic AnimalsHuey, David W. (David Worley) 05 1900 (has links)
A research program was developed to investigate basic and applied aspects of toxicity, both lethal and sublethal, of hemoxidants, particularly nitrite, on fish, non-fish aquatic vertebrates, and crayfish. The major objectives of this research were to determine A) acute and sublethal toxicity of nitrite to selected aquatic organisms: 1. aquatic salamander larvae, Ambystoma texanum, 2. swamp crayfish, Procambarus simulans, 3. bluegill, Lepomis macrochirus, 4. bullfrog, tadpoles, Rana catesbiana, 5. channel catfish, Ictalurus punctatus, B) the influence of environmental chloride on acute and sublethal exposures to hemoxidants: 1. on acute nitrite toxicity to salamander larvae, crayfish, and bluegill, 2. on nitrite-induced methemoglobinemia in bullfrog tadpoles, Rana catesbian, C) the effect of environmental hydrogen ion concentrations (pH) on acute nitrite toxicity 1. to the crayfish, Procambarus simulans, 2. to the bluegill, Lepomis macrochirus, D) the effect of temperature in sublethal exposures to nitrite 1. methemoglobin formation in channel catfish exposed at different acclimation temperatures, 2. recovery from methemoglobinemia at different acclimation temperatures, E) the effect of the fish anesthetic TMS-222 on nitrite-induced methemoglobinemia in channel catfish 1. supression of nitrite-induced methemoglobinemia, 2. dose-response curve for TMS-222 induced methemoglobinemia, and F) if a methemoglobin reductase system is present in channel catfish.
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Bioremediation of Chromium : Mechanisms and Biosensing ApplicationsPrabhakaran, Divyasree C January 2015 (has links) (PDF)
Water pollution, especially caused due to the indiscriminate release of heavy metals as a result of anthropogenic activities is a major concern worldwide. Chromium, a heavy metal, regardless of its commercial importance has found to be a potent water pollutant. Chromium generally exist as hexavalent (Cr(VI)) and trivalent (Cr(III)) chromium in the environment. Cr(VI) is ascertained to be more toxic compared to Cr(III) and the former is identified as a carcinogen by the World Health Organisation (WHO). Some of the conventional methods currently available for chromium pollution mitigation are not cost effective and most importantly lead to secondary pollution in the form of sludge. Bioremediation is a promising alternative technique which is also ecofriendly. The bioremediation process utilises biological materials such as microorganisms and agricultural byproducts. Biosorption is a bioremediation process that is a surface related phenomenon involving adsorption of contaminant chromium ions onto the binding sites of the biosorbents. In addition to the efforts made to the remediation of chromium, continuous monitoring of chromium contaminant level in polluted water bodies becomes imperative.
The present research study encompasses findings related to bioremediation and detection of chromium ions using bacterial cells. The first part of the dissertation involves studies pertaining to the bioremediation of chromium ions using different bacterial strains as biosorbent. For the study, bacterial strains procured from a microbial culture collection bank as well as those isolated from chromium polluted water samples collected from an industrial site were assessed for their ability to remediate chromium. The next aim of the study was to elucidate the mechanisms involved in the bioremediation of chromium ions by the bacterial cells for which the different characterisation methods such as, Fourier Transform Infrared (FTIR) spectroscopy, Energy Dispersive Spectroscopy (EDS), X-ray Photoelectron Spectroscopy (XPS) and zeta potential measurements which enabled to throw light on the reactions occurring at the bacterial cell surface-chromium solution interface. The later part of the study examines the capability of the bacterial strains used in the bioremediation studies as sensors for the detection of Cr(VI) and Cr(III) ions by adopting electroanalytical techniques, such as, Cyclic Voltammetry (CV) and Cathodic Stripping Voltammetry (CSV), wherein a microbe-modified Carbon Paste Electrode (CPE) was used as the working electrode in a typical three electrode electrochemical cell with Saturated Calomel Electrode (SCE) and platinum wire used as the reference and auxiliary electrodes respectively.
The key objectives of the present study are as follows:
(i) To study the bioremediation of Cr(VI) and Cr(III) ions present in aqueous solutions using two bacterial strains procured from a microbial culture collection bank as biosorbents. The bacterial strains used were Corynebacterium paurometabolum (Cp), a Gram positive bacterium and Citrobacter freundii (Cf), a Gram negative bacterium. The various factors affecting the biosorption process are to be investigated.
(ii) To isolate and identify bacterial strains from water samples collected from chromium contaminated mining site in Sukinda, Odisha, India, by adopting appropriate microbiological and molecular biological procedures.
(iii) To study the various factors affecting bioremediation of Cr(VI) using the mine isolates (Chromobacterium sp. (Cb) and Sphingopyxis sp. (Sp)) both Gram negative, as biosorbents.
(iv) To elucidate the mechanisms adopted by the chosen bacterial cells in the bioremediation of chromium.
(v) To develop an electrochemical-microbial sensor by modifying the Carbon Paste Electrode (CPE) using the bacterial strains for the detection of Cr(VI) and Cr(III) ions present in aqueous solutions.
(vi) To determine the capability of the developed sensor in the detection of Cr ions in mine water samples collected from Sukinda chromite mine in Odisha, India.
(vii) To elucidate the mechanisms occurring at the bio-modified electrode–solution interface.
A compendious description of the findings from the present work is given below:
The capability of two bacterial strains procured from a microbial culture collection bank (MTCC), Corynebacterium paurometabolum (Gram positive bacterium) and Citrobacter freundii (Gram negative bacterium) as biosorbents for Cr (VI) and Cr(III) ions was assessed. Further, it became of interest to translate the studies related to bioremediation to an industrial situation. For this, bacterial strains were isolated from chromium contaminated water samples collected from surface water of Sukinda chromite mine in Odisha, India. Based on detailed microbiological and molecular biological protocols, two strains of bacteria were identified and characterised as Chromobacterium sp. and Sphingopyxis sp. The bioremediation efficiency of the strains was evaluated taking into consideration the various factors such as effect of contact time of bacterial cells with the chromium ions, pH of the chromium ion solution, biomass loading and initial chromium ion concentration. The Cr(VI) biosorption efficiency obtained for C. freundii was found to be about 59 %, followed by Sphingopyxis sp. and C. paurometabolum ≈ Chromobacterium sp. in the range of 50 % to 55 %. Subsequent to interaction of the bacterial
cells with the Cr(VI) solution, the residual chromium was found to be in the form of Cr(III) ions. Hence, complete bioremediation of Cr(VI) could be achieved in terms of both biosorption and bioreduction processes using all the bacterial strains. It was found that the bioreduction process occurring in conjunction with the biosorption process resulted in nil concentration of Cr(VI) ions in the bulk solution. Similarly, studies related to bioremediation of Cr(III) using C. paurometabolum and C. freundii bacterial strains were also performed with higher biosorption efficiency achieved for the former, 50 % compared to 30 % obtained for C. freundii bacterial cells. The bioremediation of Cr(III) ions by the bacterial cells is achieved by the biosorption process. Biosorption of Cr ions by all the bacterial strains were found to follow a typical Langmuirian behaviour. The bioremediation process by the bacterial strains was also evaluated using suitable kinetic models and the results indicated that the bioremediation of Cr(VI) and Cr(III) by C. paurometabolum and C. freundii respectively followed pseudo first order kinetics, while the bioremediation of Cr(VI) by C. freundii, Chromobacterium sp. and Sphingopyxis sp. followed pseudo second order kinetics.
It becomes of importance to ascertain the mechanisms of bioremediation of chromium ions by the bacterial cells and for this, different characterisation methods were adopted that helped in deducing the reactions occurring at the bacterial cell surface-chromium solution interface. The involvement of chemical forces in the bioremediation process was corroborated by the achievement of only partial desorption of chromium ions from the biosorbed bacterial cells. This was further confirmed by the Gibbs free energy (∆G) values, which were found to be in the range of -25 to -30 kJ/mol. FTIR spectral studies provided evidence in support of the key functional groups present on the bacterial cell surface such as, –OH, -COOH and –NH, which facilitated the binding with chromium. The EDS data for chromium biosorbed bacterial cells showed peaks corresponding to chromium, thereby confirming the binding of chromium by the bacterial cells. The redox state of chromium bound on the bacterial cell surface was determined with the help of XPS analysis. In the Cr2p XPS spectra obtained for the bacterial cells interacted with Cr(VI), it was interesting to observe a peak corresponding to Cr(III) in addition to Cr(VI), unequivocally indicating that the Cr(III) formed via bioreduction was not only released into the bulk solution but also got biosorbed on the bacterial cell surface. Apparent shifts in the binding energy values for the bacterial cells interacted with chromium were observed in the spectra recorded corresponding to C1s, O1s, N1s, P2p and S2p as compared to the spectra obtained for the bacterial cells alone. This attests to the fact that the functional groups corresponding to the elements mentioned are involved in chemical interaction with the chromium ions or are involved in the donation of electrons to bring about reduction of Cr(VI) to the less toxic Cr(III). The variation in the charge of the bacterial cell surface before and after interaction with chromium ions was monitored by performing zeta potential measurements as a function of pH. The surface charge of the bacterial cells alone was found to be negative over a wide range of pH. Subsequent to interaction of the bacterial cells with the negatively charged oxyanions of Cr(VI) ions, the surface charge was observed to be less electronegative, which further confirmed the binding of the positively charged Cr(III) ions formed via bioreduction on the bacterial cell surface. Similar results were also observed in the case when cells were allowed to interact with Cr(III) ions. The shifts in the iso-electric point for bacterial cells interacted with chromium ions further testified to the involvement of chemical binding forces in the bioremediation process. The findings obtained from the different characterisation methods enabled in understanding the reactions that are occurring at the bacterial cell surface-Cr solution interface. Initially, biosorption via electrostatic interaction of negatively charged oxyanions of Cr(VI) with the positively charged amino groups
present on the bacterial cell surface takes place. Subsequent to the biosorption of Cr(VI) ions, the adjacent electron donating functional groups containing ligands present on the bacterial cell surface reduce Cr(VI) to Cr(III) via the reactions shown below:
Bioreduction involving –OH group
Bioreduction involving –SH group
It can be seen that, the reactions involving bioreduction of Cr(VI) in the form of chromate oxyanion to Cr(III) involving hydroxyl and thiol group present on the bacterial cell surface result in the formation of intermediates, chromate-oxy and chromate-thio ester respectively. These intermediates facilitate the transfer of electrons from oxygen/sulphur donor centers to Cr(VI) acceptor molecule, thereby resulting in the reduction of Cr(VI) to Cr(III). The Cr(III) ions thus formed are then either released into the bulk solution or get complexed with the binding groups present on the bacterial cell surface.
The next objective was to explore the potential of bacterial strains as sensors for the detection of Cr(VI) and Cr(III) ions. The chromium ions were detected using CV and CSV, both of which are electroanalytical techniques. For this, CPE was coated with the bacterial strains, C. paurometabolum, C. freundii, Chromobacterium sp. and Sphingopyxis sp., and the modified electrode was used as the working electrode in a typical three electrode electrochemical cell. These biosensors developed using each of the aforementioned strains resulted in a ~ 2 to 2.5 fold improved performance compared to the bare CPE for the detection of Cr(VI) ions, due to the binding ability of the various functional groups present on the bacterial cell surface. The lower limit of detection (LLOD) obtained for Cr(VI) and Cr(III) ions using CV technique was found to be 1x10-4 M and 5x10-4 M respectively. The LLOD was further improved to 1x10-9 M and 1x10-7 M for Cr(VI) and Cr(III) respectively using CSV. From the voltammograms obtained, it was postulated that the different functional groups present on the bacterial cell surface facilitate the detection of the chromium ions. Additionally, the developed microbial sensors were also found to be capable of detecting Cr(VI) ions in mine water samples collected from Sukinda chromite mine Odisha, India.
In summary, the mechanisms of bioremediation of toxic Cr(VI) ions have been delineated as comprising of both biosorption and bioreduction processes. The residual Cr(VI) concentration subsequent to the treatment of the Cr(VI) aqueous solution with the bacterial cells was found to be nil, which meets the regulatory limit of 0.05 mg L-1 put forward by the US-Environmental Protection Agency (EPA) for a safe effluent discharge. Moreover, it has also been demonstrated that the chosen bacterial strains could be used as sensors for the detection of upto nanomolar concentration of Cr(VI) ions, under optimum conditions.
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Identification of the sediment-associated contaminants in the Illinois River Complex using a toxicity identifcation evaluation (TIE)Mehler, Wesley Tyler 01 December 2009 (has links)
The difficulty of assessing risk of sediment-associated contaminant mixtures to benthic ecosystems is often attributed to understanding the bioavailable fraction of each contaminant. These issues have led to the development of the toxicity identification evaluation (TIE). Past pore water TIE testing on Illinois River sediments has indicated that ammonia was the primary contaminant. The current study, however, suggests that ammonia is no longer the primary contaminant of concern, but rather non-polar organics, including polycyclic aromatic hydrocarbons, are the primary cause for toxicity in the Illinois River Complex (IRC). Summer of 2007 testing showed that six out of the seven sites that proceeded to Phase I testing exhibited a significant increase in survival with the addition of the non-polar organic amendment powdered coconut charcoal (PCC), while zeolite (ammonia amendment) and Resin Tech SIR 300 (cationic metals amendment) did not significantly increase survival suggesting that non-polar organics are the source of toxicity. In addition, Phase II testing suggested that concentrations of PAHs were high enough to cause the observed toxicity, which confirmed the results of Phase I testing. Additional seasonal-based sampling (i.e., fall, winter, spring, and summer 2008) supported the summer findings, with little variation between toxicity and concentrations, with 46% of the sites being improved with the addition of PCC in Phase I testing. The results of Phase I and Phase II contradicted past pore water TIE studies as non-polar organics were suggested as the source of toxicity rather than ammonia. Thus, both pore water and whole sediment TIE methodologies were used on two selected sites. The results of this study suggested that discordance between the past pore water TIEs and the current whole sediment TIE were attributed to the methodologies and on a lesser note the test organisms used. The present study provides data that could be used in combination with previous work to more accurately characterize the sources and spatial trends of toxicity in Illinois River sediments for future risk assessment and mitigation. Furthermore, the present study showed that while TIE methodologies are a valuable tool in assessing risk associated with contaminants in aquatic system, further research in understanding the role that each TIE method may serve in risk assessment is also important.
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The safety and immunostimulatory properties of amorphous silica nanoparticles < 10 nm in diameterVis, Bradley January 2018 (has links)
Humans are exposed to high levels of amorphous silica on a daily basis, via the diet and the use of cosmetic and pharmaceutical products. Amorphous silica particles (10-200 nm) have also been developed for use in biomedical applications, including as binding agents in tissue repair, drug and gene therapy delivery agents, coatings for medical contrast agents and as vaccine adjuvants. Numerous studies have already been conducted to evaluate the cellular toxicity of these silica particles but still little is known about their effects both in vitro and in vivo, especially of nanosilica particles under 10 nm in diameter. The aim of this thesis was to investigate the cellular and in vivo activity of < 10 nm diameter nanosilica particles with different properties (e.g., size and dissolution rate in dilute conditions) as it may infer upon safety after exposure via the diet and intravenous administration (biomedical applications). First, the cytotoxicity of sub-10 nm nanosilica particles, fully characterized by size, dissolution rate, zeta-potential and by NMR spectroscopy, on immune cell function was assessed using transformed and cancerous cell lines and primary cells. The particles were toxic to the immune cells in a dose dependent manner and impaired certain cellular functions. Primary cells were most susceptible to nanosilica induced death and, of the primary cells, phagocytes were most susceptible to its cytotoxicity. Further investigations were conducted to assess the effect of nanosilica on T cells, as there was evidence suggesting that nanosilica particles were directly interacting with these cells. Nanosilica particles 3.6 nm in diameter were found to have a significant effect on T cell function. The particles induced numerous markers of T cell activation, including CD25 and CD69 on CD4 T cells, CD8 T cells, gamma-delta T cells and NK/NKT cells, CD95 on CD4 and CD8 T cells, CD40L, FoxP3, LAP, GARP on CD4 T cells, and IFN-gamma production, but it did not induce T cell proliferation. The particles were found to activate T cells regardless of their antigenic specificity. Further investigations showed that nanosilica interacts with the T cell receptor complex, the first documented case of a non MHC-coated nanoparticle directly interacting with this receptor complex. The nanoparticulate induced signalling through Zap70, LAT, and, eventually, through NFAT but not through MAPK. Similar signalling in the literature has been shown to induce a hyporesponsive T cell state (anergy) or activation induced cell death. The induction of the CD25 and CD69 T cell activation markers was limited to nanosilica particles below 10 nm in size, while similarly sized iron hydroxide nanoparticles (3-5 nm) only induced low levels of CD69 expression on T helper cells. Finally, it was shown that nanosilica is capable of inducing T cell activation in whole blood, though the T cell responses were greatly attenuated. Although identification of activation pathway in vivo remains elusive, the nanosilica particles were shown to have therapeutic value, decreasing murine subcutaneous tumour growth rate and significantly reducing the formation of lung metastases. Whether these in vivo responses are related to T cell activation identified in vitro remains unclear.
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Compatibilidade de fungos entomopatogênicos com agroquímicos utilizados no manejo integrado da cultura da cana-de-açúcar /Botelho, Aline Aparecida Alves. January 2010 (has links)
Orientador: Antonio Carlos Monteiro / Banca: Inajá Marchizeli Wenzel / Banca: Elisângela de Souza Loureiro / Resumo: No manejo integrado da cana-de-açúcar são utilizados fungos entomopatogênicos para o controle de insetos e também diversos agroquímicos visando aumento de produtividade. Porém, vários destes agroquímicos podem interferir na sobrevivência de Beauveria bassiana e Metarhizium anisopliae. Portanto, o objetivo deste trabalho foi avaliar a toxicidade dos agroquímicos mais utilizados no manejo da cana-de-açúcar para B. bassiana e M. anisopliae em experimentos feitos com a utilização em meio de cultura e de solo. Nos ensaios com meio de cultura, os fungos foram inoculados em meio de batata, dextrose e ágar (BDA) contendo diversos inseticidas (4), herbicidas (7) e maturadores (3). Avaliou-se o crescimento, a esporulação e a viabilidade, e com base nesses parâmetros fez-se a classificação toxicológica dos agroquímicos. Para verificar se o efeito encontrado em meio de cultura se mantém no ambiente do solo, foram usados os agroquímicos que apresentaram maior toxicidade no ensaio com meio de cultura. Nesta etapa os fungos foram inoculados nos solos argiloso e arenoso esterilizados, contendo os agroquímicos nas doses recomendadas pelos fabricantes, observando-se as seguintes formas de aplicação: T1 - inoculação do fungo no solo 1 hora antes da aplicação do agroquímico; T2 - inoculação do fungo no solo 1 hora após a aplicação do agroquímico; T3 - inoculação do fungo no solo 48 horas após a aplicação do agroquímico. Avaliou-se a sobrevivência dos fungos por um período de sete dias através das unidades formadoras de colônias (UFC) em placas de Petri. Nos ensaios com meios de cultura, os inseticidas à base de Fipronil (Regente®) e Thiametoxan (Actara®) foram compatíveis com os fungos, mas Aldicarbe (Temik®) foi considerado tóxico. A maior parte dos herbicidas avaliados foram classificados como tóxicos aos entomopatógenos, mas aqueles formulados com Imazapir... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In the management of sugarcane are used entomopathogenic fungi to control insects; and various agrochemicals aimed at increasing productivity. However, several of these agrochemicals may interfere with survival of Beauveria bassiana and Metarhizium anisopliae. Therefore, this research had the objective to evaluate the toxicity of agrochemicals used in handling of sugarcane to B. bassiana and M. anisopliae in experiments in culture medium and soil. In tests in culture medium, the fungi were inoculated on potato dextrose agar (PDA) containing various insecticides (4), herbicides (7) and ripeners (3). It were evaluated the growth, sporulation and viability, and based on these parameters became the toxicological classification of agrochemicals. To examine whether the effect found in the culture medium remains in the soil environment, were used agrochemicals that showed higher toxicity in culture medium assays. At this stage the fungi were inoculated in clay and sandy soils sterilized, containing the chemicals in the recommended dosages, observing the following application forms: T1 - inoculation of the fungi in soil 1 hour before to herbicide application, T2 - inoculation fungi in the soil 1 hour after herbicide application, T3 - inoculation of the fungi in the soil 48 hours after herbicide application. It was evaluated the survival of the fungi for a period of seven days through the colony forming units (CFU) in Petri dishes. Insecticides based on Fipronil (Regente®) and Thiamethoxan (Actara®) are compatible with the fungi, but Aldicarbe (Temik®) proved to be toxic. Most of the herbicides evaluated were classified as toxic to entomopathogenic fungi, but those made with Imazapir (Contain®), Glyphosate (Glifosato®) and Metribuzin (Sencor®) were considered compatible. Among the ripeners only Glyphosate (Round up®) showed compatibility with B. bassiana and M. anisopliae... (Complete abstract click electronic access below) / Mestre
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Avaliação da toxicidade reprodutiva da sinvastatina em Ratos machos adultos /Banzato, Thais Petrochelli. January 2013 (has links)
Orientador: Wilma De Gravas Kempinas / Banca: Raquel Fantin Domeniconi / Banca: Glaura Scantamburlo Alves Fernandes / Resumo: As estatinas são amplamente utilizadas no tratamento da hiperlipidemia e estão entre as drogas com maiores índices de vendas no mundo. Seu efeito se dá através da inibição competitiva da HMGCoA redutase, uma enzima limitante da síntese de colesterol que catalisa a conversão de HMG-CoA em mevalonato, interrompendo a cascata da síntese do colesterol e isoprenóides. Para os ensaios in vitro de reatividade farmacológica, ratos (n = 5) foram eutanaziados e epidídimo, canal deferente, e glândula seminal foram removidos. Após isso, os tecidos foram isolados e montados em câmaras musculares para o registro digital do desenvolvimento da tensão isométrica. Foi construída uma curva concentração- resposta à noradrenalina com a sinvastatina nas concentrações 3, 10, 30 e 100 μM. Não houve alterações na sensibilidade à noradrenalina nos ductos deferente e epididimário entre os grupos. Esses resultados estão relacionados com o não comprometimento da motilidade espermática e tempo de trânsito espermático pelo epidídimo em estudo realizado com animais expostos a 20 e 40 mg/Kg/dia de sinvastatina / Abstract: Statins are lipid lowering agents extensively used in human clinical medical. They exert their effects through inhibition of HMG-CoA reductase, a crucial enzyme in cholesterol synthesis. Since cholesterol is the precursor of steroid hormones, drugs that decrease cholesterol may damage male reproductive function. Investigate the effects of the exposure to different doses of simvastatin on the reproductive parameters of adult male Wistar rats. Thirty rats were randomly assigned into three groups: simvastatin (20 or 40 mg/kg), control (vehicle - DMSO/oil), and were treated for 30 days orally for evaluation of reproductive parameters after euthanasia. Weight of the reproductive organs; sperm counts, motility and morphology; histopathology; hormonal levels and fertility. The weight of reproductive organs, sperm motility and histopathology analysis were similar among groups. There was a decrease in sperm production and epididymis sperm number, uterus weight with fetuses, implant and live fetuses numbers in simvastatin groups. The animals exposed to simvastatin showed an increase in the pre-implantation loss and sperm with abnormal morphology. The observed effects on reproductive parameters could be associated with toxic effects of simvastatin on spermatogenesis, causing potential damage to male fertility / Mestre
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Tolerância de cana-de-açúcar a herbicidas avaliada pela diferença testemunha pareada e tratamento /Schiavetto, Ana Regina. January 2010 (has links)
Resumo: Com o objetivo de avaliar a tolerância de cultivares de cana-de-açúcar a misturas de herbicidas aplicados em pós-emergência inicial da cultura o experimento foi conduzido em área de produção comercial da Usina São Martinho, localizada no município de Pradópolis, SP. O estudo foi desenvolvido em campo no delineamento de blocos casualizados em esquema fatorial com 48 tratamentos em duas repetições. Os tratamentos foram constituídos pelas cultivares (RB855453; RB845257, SP90-3414, SP90-1638, SP89-1115; SP81-3250, IAC91-2218 e IAC91-5155) e pelos herbicidas T1=(sulfentrazone (500 g ha-1) + diuron (842,4 g ha-1) + hexazinone (237,6 g ha-1); T2=metsulfuron-methyl (6 g ha-1) + sulfentrazone (750 g ha-1); T3=diuron (842,4 g ha-1) + hexazinone (237,6 g ha-1) + clomazone (900 g ha-1); T4=metribuzin (1920 g ha-1) + diuron (842,4 g ha-1) + hexazinone (237,6 g ha-1); T5=diuron (1599 g ha-1) + hexazinone (201 g ha-1) + MSMA (360 g ha-1); T6=ametryn (1097,25 g ha-1) + trifloxysulfuron-sodium (27,75 g ha-1) + diuron (702 g ha-1) + hexazinone (198 g ha-1)) e uma testemunha pareada para cada parcela. Os herbicidas foram aplicados sobre a palha oriunda da colheita da cana-de-açúcar em pré-emergência das plantas daninhas e pós-emergência inicial da cultura. Todas as parcelas mantidas na ausência de plantas daninhas durante todo período experimental. Cada parcela foi constituída por seis linhas, sendo uma central de meia parcela, tratada (TH); e a central da outra meia parcela, testemunha pareada (TP). As outras linhas foram bordaduras Foram avaliados aos 20 e 50 dias após aplicação (DAA) os sintomas visuais de fitointoxicação, o teor relativo de clorofila total e a razão de fluorescência da clorofila a; medições de altura foram feitas aos 30, 90 e 180 DAA e de estande aos 30, 90 e 180 DAA. Por ocasião da colheita aos 210 DAA foram avaliados o diâmetro dos colmos, os teores... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The experiment was conducted sugarcane commercial area from Sao Martinho will in Pradópolis, SP, in order to evaluate the tolerance of sugarcane cultivars to the association of herbicides applied post-emergence culture. The study was conducted in the field in a randomized block design in factorial with 48 treatments in two replications. The treatments consisted of cultivars (RB855453, RB845257, SP90-3414, SP90-1638, SP89-1115, SP81-3250, and IAC91-2218 IAC91-5155) and the herbicide T1=(sulfentrazone (500 g ha-1) + diuron (842,4 g ha-1) + hexazinone (237,6 g ha-1); T2=metsulfuron-methyl (6 g ha-1) + sulfentrazone (750 g ha-1); T3=diuron (842,4 g ha-1) + hexazinone (237,6 g ha-1) + clomazone (900 g ha-1); T4=metribuzin (1920 g ha-1) + diuron (842,4 g ha-1) + hexazinone (237,6 g ha-1); T5=diuron (1599 g ha-1) + hexazinone (201 g ha-1) + MSMA (360 g ha-1); T6=ametryn (1097,25 g ha-1) + trifloxysulfuron-sodium (27,75 g ha-1) + diuron (702 g ha-1) + hexazinone (198 g ha-1)) and a paired control for each plot. Herbicides were applied over the straw coming from the crop of sugarcane in pre-emergence weed and post-emergence of the crop, all plots being maintained in the absence of weeds throughout the experimental period. Which plot was formed by 6 rows of sugarcane. The central one of each 3 rows were used as treated (TH) and paired control (TP). The other rows were borders. Were evaluated at 20 and 50 days after application (DAA) visual symptoms, total chlorophyll and the ratio of chlorophyll a fluorescence; height measurements were made at 30, 90 and 180 DAA and stand at 30, 90 and 180 DAA. At harvest at 210 DAS were evaluated for stem diameter, the brix, purity, pol, sugars (AR) in the juice, cane fiber, total sugar recovered (ATR) and production of the stems (t ha-1). The mean difference, TP-TH, was subjected to the t tests, using the hypothesis of the difference with zero... (Complete abstract click electronic access below) / Orientador: Dilermando Perecin / Coorientador: Carlos Alberto Mathias Azania / Banca: Maximiliano Salles Scapari / Banca: Núbia Maria Correia / Mestre
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The safety and toxicity of MPA-CdTe quantum dots in legume plantsOmar, Zaahira January 2017 (has links)
Magister Scientiae - MSc (Biotechnology) / The expansion of nanotechnology, resulting in multitudes of consumer and industrial
products, causes concern amongst the scientific community regarding the risks associated
with the release of nanomaterials into the environment and its subsequent effects on plants.
Therefore, the focus of this study was aimed at investigating the effects of MPA-capped CdTe
and carbon QDs on legumes plants namely P. vulgaris and G. max. Fluorescent imaging
revealed that QDs were translocated from the roots to the aerial parts of the plant and
accumulated in the edible parts of P. vulgaris. Subsequent physiological and biochemical
tests revealed that both QD types induced oxidative stress as biological markers for stress
including lipid peroxidation and cell death were elevated. In addition, carbon QDs displayed
lower toxicity in comparison to MPA-CdTe QDs, but still possessed the ability to induce
oxidative stress in plant cells. However, the effects were more pronounced in G. max in
comparison to P. vulgaris; and more so with MPA-CdTe QDs than carbon QDs. Furthermore,
MPA-CdTe and carbon QDs altered the concentrations and translocation of essential macro
and microelements that are required for plant growth and development. This may have
detrimental effects on crop productivity and yield, with negative implications on food quality
and food security. / 2021-08-31
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