O objetivo do presente estudo foi sintetizar e caracterizar um material reparador para uso endodôntico com propriedades anti-inflamatória, antimicrobiana e remineralizante. A pasta experimental tem como propósito ser um sistema carreador de fármacos para regiões de difícil acesso em Odontologia. A apresentação do material é em forma de pó:líquido. No pó se encontra α-fosfato tricálcico, tungstato de cálcio e microesferas de amoxicilina (AMX-MS), já no líquido estão contidas nanocápsulas de indometacina (IndOHNC). A pasta experimental foi testada em relação a suas características físicoquímicas e biológicas. As AMX-MS obtiveram tamanho de 1,604 μm ± 0,08, forma esférica confirmada por MEV e teor da droga foi 1,63 mg g-1. As IndOHNC obtiveram tamanho de 162 ± 7,5 nm e forma esférica confirmada por MET. O teor do fármaco foi de 1 mg mL-1 ± 0,02. O escoamento da pasta foi de 18.56 ± 0.29, a espessura de película obtida foi 33 μm e radiopacidade de 1,81 mmAl. A pasta experimental demonstrou atividade antibacteriana contra o Enterococcus faecalis. A maior concentração de pasta experimental apresentou o maior valor em relação à viabilidade celular, com 187,03% no teste SRB. A atividade da enzima fosfatase alcalina e a formação de nódulos mineralizados obtiveram um gradual aumento em função do tempo. A migração celular demonstrou fechamento da ferida, e a pasta experimental foi capaz de acelerar o processo (p<0.05). Em conclusão, a pasta experimental demonstrou propriedades físico químicas e biológicas confiáveis, podendo ser um material promissor para o reparo da região periapical. / The aim of this study was to synthesize and characterize a new reparative material with anti-inflammatory, antimicrobial and remineralizing properties. The reparative material was developed to be a drug delivery system for regions with difficult access in Dentistry. The formulation is presented in powder/liquid. The powder is composed of α-tricalcium phosphate, calcium tungstate and amoxicillin microspheres (AMX-MS). The liquid is composed of nanocapsules containing indomethacin (IndOH-NC). The physicochemical and biological properties of the experimental endodontic paste were evaluated. The AMX-MS obtained a mean size of 1.604 μm ± 0.08, spherical shape and the encapsulation capacity was 1.63 mg g-1. IndOH-NCs obtained a mean size of 162 ± 7.5 nm and spherical shape confirm by MET. The content of the encapsulated drug was 1 mg mL-1 ± 0.02. The experimental paste flow was 18.56 ± 0.29 mm, mean film thickness was 33 μm and radiopacity equivalent to 1.81 mmAl. The experimental paste showed antibacterial activity against Enterococcus faecalis. The highest concentration of experimental paste presented the highest value in cell viability (187.03% in SRB test). The activity of the phosphatase alkaline enzyme and the formation of mineralized nodules showed a gradual increase as a function of time. Cell proliferation showed continuous wound closure, and the experimental paste was able to accelerate the process (p<0.05). In conclusion, the experimental paste demonstrated reliable physicochemical and biological properties, and it could be a promising material for periapical region repair.

In culture, exposure to penicillin and other stressors induce chlamydiae to enter a non-infectious but viable state termed persistence. Chlamydiae may reenter their normal developmental cycle after stressor removal. Though aberrant RB similar to those present in culture models of persistence have been observed within infected tissues, the existence of persistent chlamydiae has not been definitively demonstrated in vivo. As a result, the role of persistent organisms in pathogenesis is undefined. In order to establish an experimentally tractable model of in vivo persistence, Chlamydia muridarum vaginally-infected mice were gavaged with either water or amoxicillin (amox). Vaginal swabs were collected for chlamydial titration and RNA isolated for quantification of pre-16s rRNA. Uterine tissue was analyzed by transmission electron microscopy (TEM). Although amox-treatment reduced vaginal shedding by >99%, C. muridarum pre-16s rRNA accumulation was unchanged by treatment. These data indicate that the amox-exposed organisms were viable but not infectious. Furthermore, TEM analyses demonstrated that inclusions in amox-treated animals contained primarily large, aberrant RB, but those observed in untreated control animals were normal. Collectively, these data suggest that amoxicillin treatment induces C. muridarum to enter the persistent state in vivo. This model also represents the first experimentally tractable animal model of chlamydial persistence.

No description available.

Hintergrund: Zahlreiche Studien haben den therapeutischen Nutzen von systemischem Antibiotika in der Behandlung schwerer Parodontitis gezeigt. Bisher ist allerdings noch nicht geklärt, welches antibiotische Behandlungkonzept das Geeignetste ist. Daher sollen in einer randomisierten, klinischen Blindstudie zwei verschiedene, systemische Antibiotika adjuvant zur konventionellen, instrumentellen Behandlung von Patienten mit rapid progressiver Parodontitis (RPP) miteinander verglichen werden. Material und Methode: 33 Patienten mit klinisch und radiologisch gesicherter RPP-Diagnose wurden auf 2 Gruppen verteilt: (1) AM-Gruppe (n=17): 500 mg Amoxicillin und 250 mg Metronidazol (3*/ Tag - 10 Tage), (2) D-Gruppe (=16) 200mg Doxycyclin am 1.Tag und 100mg Doxycyclin 13 Tage. Zu Beginn erhielten alle Patienten 3* eine professionelle Zahnreinigung, und anschlie§end Scaling und Wurzelglättung unter Lokalanästhesie in 2 Sitzungen. 3 Monate später wurde ein Recall und die Antibiose durchgeführt. Im Abstand von jeweils 3 Monaten erfolgten 2 weitere Recallsitzungen. Nach erfolgreicher Mundhygieneinstruktion und zu allen Recallsitzungen wurden alle klinischen Parameter wie Taschentiefe, relatives Attachmentlevel und das Bluten bzw. Pus nach Sondieren mit der Florida probe eruiert. Die Bestimmung 8 verschiedener Parodontalpathogene wurde mit dem DNS-Sondentest von Meridol durchgeführt. Die mikrobiologischen Proben wurden mit sterilen Papierspitzen an den vier tiefsten Taschen vor der Antibiose und zu den anschlie§enden Recalls entnommen und mit der Gensondentechnik im Labor der Wybert GmbH elmex Forschung, Lörrach, analysiert. Zur Bestimmung des IL-1-Genpolymorphismus wurde venöses Blut in der 1. Sitzung abgenommen. Die Auswertung erfolgte mit dem GenoType(R) PRTest (Hain Diagnostika GmbH). Ergebnisse: Die klinischen Parameter zeigen sowohl durch die konservative als auch durch die antibiotisch adjuvante Therapie eine signifikante klinische Verbesserung (p / Background: Several studies have shown a therapeutical benefit from systemic antibiotics in the treatment of severe periodontitis. However, it has not yet been layed down which concept of antibiotic treatment is the best. Therefore the purpose of this study is to compare two different systemic antibiotics adjunctive to a conventional, mechanical treatment of patients with rapidly progressive periodontitis (RPP) in a randomised, blinded, clinical trial. Material and methods: 33 patients with a clinically and radiographically confirmed diagnosis of RPP were distributed in two groups: (1) AM-group (n=17): 500 mg amoxicillin and 250 mg metronidazole (3*/ d - 10days), (2) D-group (=16) 200mg doxycyclin on the 1st day and 100mg doxycyclin for 13days. In the beginning the patients received 3* professional tooth cleaning, and subsequently scaling and root planning under local anaesthesia in two sessions. 3 months later a recall visit and the antibiotic regimen were carried out. In 3 months-intervals another 2 recall visits were performed. After successfull oral hygiene instructions and during all recall visits all clinical parameters like pocket depths, relative attachment level, and bleeding and pus on probing were evaluated with the Florida probe. The determination of 8 different periodontal pathogens was performed with the DNS-Sondentest of Meridol. Before the antibiotic treatment and during the following recall visits the microbiological samples were taken from the 4 deepest pockets with sterile paper points and analysed by PCR-technique in the laboratory of Wybert GmbH elmex Forschung, Lörrach. To determine the IL-1 genetic polymorphism venous blood samples were taken in the first session. The analysis was done by GenoType(R), PRTest (Hain Diagnostika GmbH). Results: The clinical parameters show a significant clinical improve by the conservative as well as by the adjunctive antibiotic treatment (p

Professional nurses and their patients are directly influenced by insufficient medication, causing a decrease in the quality of care, delays in hospitalisation and it might lead to resistance. In some cases professional nurses have to leave the unit in search of medicine. Amoxicillin-clavulanic acid 1.2 gram for intravenous administration is prescribed to the majority of patients in the medical units in public South African hospitals. Yet there are intermitted insufficient stock levels and challenged inventory systems for amoxicillin-clavulanic acid 1.2 gram in some public hospitals. This fact is positioned against the background of a South African health system that has undergone major changes since the fall of Apartheid in 1994 and amidst major positive changes, is still challenged by overburdened hospital admissions and a quadruple disease burden. The aim of this research was to enhance optimal levels of amoxicillin-clavulanic acid 1.2 gram in medical units in public hospitals to ensure sufficient stock levels and timeous administration. The aim was achieved by identifying and describing the current supply chain of intravenous amoxicillin-clavulanic acid 1.2 gram in two medical units in a district (level 2) public hospital in the North West Province (from here referred only as North West) by identifying inefficiencies in the current supply chain and to formulate recommendations for management to enhance the supply chain of intravenous amoxicillin-clavulanic acid 1.2 gram to medical units in public hospitals. An exploratory case study approach was followed to explain the supply chain of amoxicillin-clavulanic acid 1.2 gram by utilising a qualitative, descriptive, explorative and contextual design. A case study approach was chosen as it examined single units within the context of real life as environment, which in this case were medical units in a level two public hospital, North West. The case selection was motivated and described, followed by case records of policies and standard operational procedures. Field participants included all levels of nurses (professional, enrolled and auxiliary) in medical male and female units on day and night duty, and the head of pharmacy [n=8]. Non-probable, purposive sampling was conducted according to inclusion criteria after all levels of ethical clearance and consent were granted. Three semi-structured individual interviews followed, after which two focus groups were conducted. Thematic analysis of transcriptions was done, followed by an analysis of case records regarding where after all results were integrated. Results indicated complex organisational, unit-specific and behavioural challenges that impact on the supply chain management of amoxicillin-clavulanic acid 1.2 gram and insufficient stock levels are predominantly positioned within retailer and customer aspects of the supply chain. Despite well-formulated standard operational procedures, the realisation thereof lacks, implicating a greater need for managerial control. Recommendations were formulated for management to enhance the supply chain of amoxicillin-clavulanic acid 1.2 gram in medical units in public South African hospitals integrated with good pharmacy practices. The close collaboration, mutual respect and effective communication between health professionals in the multi-professional team are reiterated. / MCur, North-West University, Potchefstroom Campus, 2015

Professional nurses and their patients are directly influenced by insufficient medication, causing a decrease in the quality of care, delays in hospitalisation and it might lead to resistance. In some cases professional nurses have to leave the unit in search of medicine. Amoxicillin-clavulanic acid 1.2 gram for intravenous administration is prescribed to the majority of patients in the medical units in public South African hospitals. Yet there are intermitted insufficient stock levels and challenged inventory systems for amoxicillin-clavulanic acid 1.2 gram in some public hospitals. This fact is positioned against the background of a South African health system that has undergone major changes since the fall of Apartheid in 1994 and amidst major positive changes, is still challenged by overburdened hospital admissions and a quadruple disease burden. The aim of this research was to enhance optimal levels of amoxicillin-clavulanic acid 1.2 gram in medical units in public hospitals to ensure sufficient stock levels and timeous administration. The aim was achieved by identifying and describing the current supply chain of intravenous amoxicillin-clavulanic acid 1.2 gram in two medical units in a district (level 2) public hospital in the North West Province (from here referred only as North West) by identifying inefficiencies in the current supply chain and to formulate recommendations for management to enhance the supply chain of intravenous amoxicillin-clavulanic acid 1.2 gram to medical units in public hospitals. An exploratory case study approach was followed to explain the supply chain of amoxicillin-clavulanic acid 1.2 gram by utilising a qualitative, descriptive, explorative and contextual design. A case study approach was chosen as it examined single units within the context of real life as environment, which in this case were medical units in a level two public hospital, North West. The case selection was motivated and described, followed by case records of policies and standard operational procedures. Field participants included all levels of nurses (professional, enrolled and auxiliary) in medical male and female units on day and night duty, and the head of pharmacy [n=8]. Non-probable, purposive sampling was conducted according to inclusion criteria after all levels of ethical clearance and consent were granted. Three semi-structured individual interviews followed, after which two focus groups were conducted. Thematic analysis of transcriptions was done, followed by an analysis of case records regarding where after all results were integrated. Results indicated complex organisational, unit-specific and behavioural challenges that impact on the supply chain management of amoxicillin-clavulanic acid 1.2 gram and insufficient stock levels are predominantly positioned within retailer and customer aspects of the supply chain. Despite well-formulated standard operational procedures, the realisation thereof lacks, implicating a greater need for managerial control. Recommendations were formulated for management to enhance the supply chain of amoxicillin-clavulanic acid 1.2 gram in medical units in public South African hospitals integrated with good pharmacy practices. The close collaboration, mutual respect and effective communication between health professionals in the multi-professional team are reiterated. / MCur, North-West University, Potchefstroom Campus, 2015

As doenças periodontais são infecções locais que apresentam morbidade e têm sido relacionadas com outras doenças ou complicações sistêmicas. Pacientes tabagistas apresentam taxas elevadas e maior predisposição às doenças periodontais severas e avançadas. A administração sistêmica de antibióticos, particularmente metronidazol (M) e amoxicilina (A), associados ao tratamento periodontal mecânico (raspagem e alisamento radiculares - RAR) tem sido amplamente estudada frente às doenças periodontais crônicas. Porém, pouco tem sido esclarecido referente aos efeitos desses tratamentos sobre Porphyromonas gingivalis e seus genótipos. Os objetivos deste trabalho foram: avaliar os efeitos clínicos (profundidade a sondagem - PS, nível de inserção clínica - NIC, índice de placa - IP, sangramento gengival - SG, sangramento à sondagem SS, e supuração - SUP) e microbiológicos (referente à presença de P. gingivalis e seus genótipos fimA II, fimA IV e ragB) após 180 dias do tratamento periodontal mecânico (RAR) associado à administração sistêmica de antibióticos (RAR+M+A), comparados ao tratamento periodontal mecânico (RAR), utilizando-se o PCR convencional (primers específicos para 16S rRNA); e relacionar a presença de P. gingivalis e seus genótipos fimA II, fimA IV e ragB com a profundidade de sondagem (PS) em pacientes fumantes com periodontite crônica. Foram avaliadas 167 amostras oriundas de sítios de 20 sujeitos tratados com RAR (n=11) e RAR + M + A (n=9), no exame inicial e 180 dias após a terapia. Parâmetros clínicos (PS, NIC, IP, SG, SS e SUP) e coletas microbiológicas foram mensuradas em ambos tempos. A detecção da freqüência de P. gingivalis foi realizada por PCR convencional, bem como para os genótipos fimA II, fimA IV e ragB. Não houve diferença estatisticamente significante entre o tratamento periodontal mecânico associado à administração sistêmica de antibióticos (RAR+M+A) e o tratamento periodontal mecânico (RAR), nos pacientes fumantes, em relação à detecção de P. gingivalis. O grupo RAR apresentou-se mais efetivo (estatisticamente significante) na redução de prevalência do genótipo ragB, em comparação ao grupo RAR+M+A, após 180 dias do tratamento. Não foi observada relação estatisticamente significante entre a prevalência de P. gingivalis e dos genótipos fimA II, fimA IV e ragB com a PS no exame inicial. / Periodontal diseases are local infections that present morbidity and have been relation with others systemic diseases or complications. Smoking patients present high levels and bigger predisposition to the severe and advanced periodontal diseases. The systemic administration of antibiotics, mainly metronidazole (M) and amoxicillin (A), associated to the mechanical periodontal treatment (scaling and root planing - SRP) has been largely researched referring to the chronic periodontal diseases. However, not much has been cleared up referring to the effects of those treatments about Porphyromonas gingivalis and its genotypes. The purpose of this research was to evaluate the clinical effects (depth probing - DP, clinical attachment level - CAL, plaque index - PI, gingival bleeding - GB, bleeding on probing - BOP, and supuration - SUP) and microbiological (referring to the presence of P. gingivalis and its genotypes fimA II, fimA IV and ragB) after 180 days of the mechanical periodontal treatment (SRP) associated to the systemic administration of antibiotic (SRP+M+A), compared to the mechanical periodontal treatment (SRP) in smoking patients with chronic periodontitis, by using the conventional PCR (specific primers to the 16S rRNA); to associate the P. gingivalis presence and its genotypes fimA II, fimA IV and ragB with depth probing (DP) of the researched population. 167 samples from the sites of 20 subjects treated with SRP (n=11) and SRP+M+A (n=9) have been evaluated, at the baseline and 180 days after the therapy. Clinical parameters (DP, CAL, PI, GB, BOP and SUP) and microbiological samples were evaluated in both moments. The detection of P. gingivalis frequence was made by using conventional PCR, and also to the genotypes fimA II, fimA IV and ragB. There was no statistically significative difference between the mechanical periodontal treatment associated to the systemic administration of antibiotics (SRP+M+A) and the mechanical periodontal treatment (SRP), in the smoking patients, related to the detection of the P. gingivalis. The SRP group showed more effective (statiscally significative) on the reduction of the genotype ragB prevalence, comparing to the SRP+M+A group, after 180 days of therapy. No statistically significative relation between the prevalence of P. gingivalis and its genotypes fimA II, fimA IV e ragB with DP at the baseline have been observed.

Fármacos tem sido foco de diversas estudos e pesquisas devido à constatação de sua ocorrência em diversos compartimentos ambientais. Esses compostos, com destaque para os antibióticos, apresentam biodegradação limitada e contínua introdução nos sistemas hídricos devido ao descarte incorreto, eliminação por excreção de parte da dose ingerida e, principalmente, pelo processo de fabricação nas indústrias farmacêuticas. Como as formas convencionais de tratamento têm se mostrado pouco efetivas, a tecnologia eletroquímica associada aos processos oxidativos avançados (POA) têm se mostrado uma maneira eficiente na degradação desses compostos. Em diversos estudos, os eletrodos de difusão gasosa (EDG) são apresentados como uma opção promissora no que diz respeito à eletrogeração de peróxido de hidrogênio, uma das principais fontes de radical hidroxila utilizado nos POA. Nesse aspecto, surgem estudos sobre modificadores que podem atuar como catalisadores nesse processo. Neste trabalho estudou-se o comportamento eletroquímico de dois modificares orgânicos suportados em matriz condutora de carbono Printex 6L. Os compostos orgânicos escolhidos, pertencentes a classe das quinonas, foram a 2-terc-butil-9,10-antraquinona (TBA) e a 9,10 fenantraquinona (FQA). Os estudos foram realizados em um eletrodo de disco/anel rotatório (RRDE), depositando-se uma microcamada porosa, contendo ou não o modificador, sobre o carbono vítreo deste eletrodo. Através dos resultados de voltametria cíclica e linear pode-se avaliar a geração de peróxido de hidrogênio, que foi superior para as microcamadas com adição dos modificadores. O material com 0,5% (m/m) de FQA mostrou-se o mais eficiente entre todos, com 30% de rendimento a mais quando comparado à matriz Printex e 6% maior quando comparada a mesma quantidade de TBA na produção do peróxido. Estudou-se também a eficiência da FQA para a produção de peróxido de hidrogênio (H2O2) a partir da reação de redução do oxigênio gasoso (O2), em eletrodos de difusão gasosa (EDG). Considerando os cinco eletrodos estudados (Printex não modificado e modificado com 0,1, 0,5, 1,0 e 2,0% de FQA) foi realizada uma avaliação sobre qual eletrodo seria o mais apto a ser utilizado nos trabalhos de degradação dos fármacos. Para isso fez-se a análise da concentração de peróxido de hidrogênio eletrogerada, o consumo energético e a cinética envolvida no processo. Os resultados mostraram um aumento significativo na produção de peróxido para os eletrodos modificados com 0,5 e 1,0% de FQA. Sendo que o eletrodo sem modificação atingiu um máximo de 215 ppm de H2O2 em um potencial de -1,4 V com um consumo energético de 29 kWh kg-1 de H2O2. O eletrodo modificado com 0,5% de FQA alcançou 566 pmm de H2O2 em um potencial de -1,4 V com um consumo energético de 14 kWh kg-1 de H2O2. Estudou-se também a degradação dos antibióticos amoxicilina e ampicilina (AMX e AMP) com anodos condutores comerciais de diamante dopados com boro. A influência da densidade de corrente aplicada (15, 30 e 60 mA cm-2) para o mesmo eletrólito de suporte (3 g / L de Na2SO4) e a mesma concentração inicial de antibióticos (100 mg dm-3 cada) foi avaliada. A mineralização total dos antibióticos foi atingida. Além disso, o processo foi encontrado para ser mais eficiente na densidade de corrente de 30 mA cm-2. Os resultados demonstram a importância dos processos eletroquímicos mediados na degradação de AMX e AMP. Esta influência foi confirmada por alguns testes em que a eletrólise foi acoplada à radiação UV ou à radiação ultrassônica. O uso de radiação UV resulta em uma degradação menos eficiente, enquanto que o ultrassom melhora um pouco a taxa de mineralização quando comparado ao processo eletrolítico simples. / Drugs have been the focus of several studies and researches due to the finding of their occurrence in several environmental compartments. These compounds, especially antibiotics, present limited biodegradation and continuous introduction into water systems because of incorrect disposal, elimination by excretion of part of the ingested dose and, mainly, by the manufacturing process in the pharmaceutical industries. As conventional mode of treatment have been shown to be ineffective, electrochemical technology associated with advanced oxidative processes (POA) has been shown to be an efficient way of degradation of these compounds. In several studies, gas diffusion electrodes (EDG) are presented as a promising option with respect to hydrogen peroxide electrogeneration, one of the main sources of hydroxyl radical used in POAs. In this aspect, studies on modifiers appear that can act as catalysts in this process. In this work the electrochemical behavior of two organic modifiers supported in Printex 6L carbon matrix was studied. The organic compounds chosen, belonging to the class of quinones, were 2-tert-butyl-9,10-anthraquinone (TBA) and 9,10-phenanthraquinone (FQA). The studies were performed on a rotating disk / ring electrode (RRDE), depositing a porous micro-layer, containing or not the modifier, on the glassy carbon of this electrode. Through the results of cyclic and linear voltammetry the generation of hydrogen peroxide can be evaluated, which was superior to the micro-layers with addition of the modifiers. The material with 0.5% (w / w) of FQA was the most efficient of all, with 30% more yield when compared to the Printex matrix and 6% higher when compared to the same amount of TBA in peroxide production . It was also studied the efficiency of the FQA for the production of hydrogen peroxide (H2O2) from the reduction reaction of gaseous oxygen (O2) in gaseous diffusion electrodes (EDG). Considering the five electrodes studied (Printex not modified and modified with 0.1, 0.5, 1.0 and 2.0% of FQA) an evaluation was made on which electrode would be the most suitable to be used in the degradation works of the drugs. For that, the analysis of the hydrogen peroxide concentration, the energy consumption and the kinetics involved in the process were analyzed. The results showed a significant increase in peroxide production for electrodes modified with 0.5 and 1.0% of FQA. Since the unmodified electrode reached a maximum of 215 ppm of H2O2 at a potential of -1.4 V with an energy consumption of 29 kWh kg-1 of H2O2. The electrode modified with 0.5% of FQA reached 566 pmm of H2O2 at a potential of -1.4 V with an energetic consumption of 14 kWh kg-1 of H2O2. The degradation of antibiotics amoxicillin and ampicillin (AMX and AMP) with commercial boron-doped diamond conducting anodes was also studied. The influence of the applied current density (15, 30 and 60 mA cm-2) for the same support electrolyte (3 g / L Na2SO4) and the same initial concentration of antibiotics (100 mg dm-3 each) was evaluated. Total mineralization of antibiotics was achieved. In addition, the process was found to be more efficient at current density of 30 mA cm-2. The results demonstrate the importance of the electrochemical processes mediated in the degradation of AMX and AMP. This influence was confirmed by some tests in which the electrolysis was coupled to UV radiation or to ultrasonic radiation. The use of UV radiation results in less efficient degradation, while ultrasound improves the rate of mineralization somewhat compared to the simple electrolyte process.

Fármacos tem sido foco de diversas estudos e pesquisas devido à constatação de sua ocorrência em diversos compartimentos ambientais. Esses compostos, com destaque para os antibióticos, apresentam biodegradação limitada e contínua introdução nos sistemas hídricos devido ao descarte incorreto, eliminação por excreção de parte da dose ingerida e, principalmente, pelo processo de fabricação nas indústrias farmacêuticas. Como as formas convencionais de tratamento têm se mostrado pouco efetivas, a tecnologia eletroquímica associada aos processos oxidativos avançados (POA) têm se mostrado uma maneira eficiente na degradação desses compostos. Em diversos estudos, os eletrodos de difusão gasosa (EDG) são apresentados como uma opção promissora no que diz respeito à eletrogeração de peróxido de hidrogênio, uma das principais fontes de radical hidroxila utilizado nos POA. Nesse aspecto, surgem estudos sobre modificadores que podem atuar como catalisadores nesse processo. Neste trabalho estudou-se o comportamento eletroquímico de dois modificares orgânicos suportados em matriz condutora de carbono Printex 6L. Os compostos orgânicos escolhidos, pertencentes a classe das quinonas, foram a 2-terc-butil-9,10-antraquinona (TBA) e a 9,10 fenantraquinona (FQA). Os estudos foram realizados em um eletrodo de disco/anel rotatório (RRDE), depositando-se uma microcamada porosa, contendo ou não o modificador, sobre o carbono vítreo deste eletrodo. Através dos resultados de voltametria cíclica e linear pode-se avaliar a geração de peróxido de hidrogênio, que foi superior para as microcamadas com adição dos modificadores. O material com 0,5% (m/m) de FQA mostrou-se o mais eficiente entre todos, com 30% de rendimento a mais quando comparado à matriz Printex e 6% maior quando comparada a mesma quantidade de TBA na produção do peróxido. Estudou-se também a eficiência da FQA para a produção de peróxido de hidrogênio (H2O2) a partir da reação de redução do oxigênio gasoso (O2), em eletrodos de difusão gasosa (EDG). Considerando os cinco eletrodos estudados (Printex não modificado e modificado com 0,1, 0,5, 1,0 e 2,0% de FQA) foi realizada uma avaliação sobre qual eletrodo seria o mais apto a ser utilizado nos trabalhos de degradação dos fármacos. Para isso fez-se a análise da concentração de peróxido de hidrogênio eletrogerada, o consumo energético e a cinética envolvida no processo. Os resultados mostraram um aumento significativo na produção de peróxido para os eletrodos modificados com 0,5 e 1,0% de FQA. Sendo que o eletrodo sem modificação atingiu um máximo de 215 ppm de H2O2 em um potencial de -1,4 V com um consumo energético de 29 kWh kg-1 de H2O2. O eletrodo modificado com 0,5% de FQA alcançou 566 pmm de H2O2 em um potencial de -1,4 V com um consumo energético de 14 kWh kg-1 de H2O2. Estudou-se também a degradação dos antibióticos amoxicilina e ampicilina (AMX e AMP) com anodos condutores comerciais de diamante dopados com boro. A influência da densidade de corrente aplicada (15, 30 e 60 mA cm-2) para o mesmo eletrólito de suporte (3 g / L de Na2SO4) e a mesma concentração inicial de antibióticos (100 mg dm-3 cada) foi avaliada. A mineralização total dos antibióticos foi atingida. Além disso, o processo foi encontrado para ser mais eficiente na densidade de corrente de 30 mA cm-2. Os resultados demonstram a importância dos processos eletroquímicos mediados na degradação de AMX e AMP. Esta influência foi confirmada por alguns testes em que a eletrólise foi acoplada à radiação UV ou à radiação ultrassônica. O uso de radiação UV resulta em uma degradação menos eficiente, enquanto que o ultrassom melhora um pouco a taxa de mineralização quando comparado ao processo eletrolítico simples. / Drugs have been the focus of several studies and researches due to the finding of their occurrence in several environmental compartments. These compounds, especially antibiotics, present limited biodegradation and continuous introduction into water systems because of incorrect disposal, elimination by excretion of part of the ingested dose and, mainly, by the manufacturing process in the pharmaceutical industries. As conventional mode of treatment have been shown to be ineffective, electrochemical technology associated with advanced oxidative processes (POA) has been shown to be an efficient way of degradation of these compounds. In several studies, gas diffusion electrodes (EDG) are presented as a promising option with respect to hydrogen peroxide electrogeneration, one of the main sources of hydroxyl radical used in POAs. In this aspect, studies on modifiers appear that can act as catalysts in this process. In this work the electrochemical behavior of two organic modifiers supported in Printex 6L carbon matrix was studied. The organic compounds chosen, belonging to the class of quinones, were 2-tert-butyl-9,10-anthraquinone (TBA) and 9,10-phenanthraquinone (FQA). The studies were performed on a rotating disk / ring electrode (RRDE), depositing a porous micro-layer, containing or not the modifier, on the glassy carbon of this electrode. Through the results of cyclic and linear voltammetry the generation of hydrogen peroxide can be evaluated, which was superior to the micro-layers with addition of the modifiers. The material with 0.5% (w / w) of FQA was the most efficient of all, with 30% more yield when compared to the Printex matrix and 6% higher when compared to the same amount of TBA in peroxide production . It was also studied the efficiency of the FQA for the production of hydrogen peroxide (H2O2) from the reduction reaction of gaseous oxygen (O2) in gaseous diffusion electrodes (EDG). Considering the five electrodes studied (Printex not modified and modified with 0.1, 0.5, 1.0 and 2.0% of FQA) an evaluation was made on which electrode would be the most suitable to be used in the degradation works of the drugs. For that, the analysis of the hydrogen peroxide concentration, the energy consumption and the kinetics involved in the process were analyzed. The results showed a significant increase in peroxide production for electrodes modified with 0.5 and 1.0% of FQA. Since the unmodified electrode reached a maximum of 215 ppm of H2O2 at a potential of -1.4 V with an energy consumption of 29 kWh kg-1 of H2O2. The electrode modified with 0.5% of FQA reached 566 pmm of H2O2 at a potential of -1.4 V with an energetic consumption of 14 kWh kg-1 of H2O2. The degradation of antibiotics amoxicillin and ampicillin (AMX and AMP) with commercial boron-doped diamond conducting anodes was also studied. The influence of the applied current density (15, 30 and 60 mA cm-2) for the same support electrolyte (3 g / L Na2SO4) and the same initial concentration of antibiotics (100 mg dm-3 each) was evaluated. Total mineralization of antibiotics was achieved. In addition, the process was found to be more efficient at current density of 30 mA cm-2. The results demonstrate the importance of the electrochemical processes mediated in the degradation of AMX and AMP. This influence was confirmed by some tests in which the electrolysis was coupled to UV radiation or to ultrasonic radiation. The use of UV radiation results in less efficient degradation, while ultrasound improves the rate of mineralization somewhat compared to the simple electrolyte process.

Compostos farmacêuticos são identificados em matrizes ambientais em ordens de grandeza de ng.L-1 a &mu;g.L-1. Dentre os fármacos, os antibióticos têm recebido atenção especial devido aos problemas que podem causar à biota aquática. O objetivo do presente estudo foi avaliar a citotoxicidade de Amoxicilina e Clavulanato de Potássio isolados e em associação para mexilhões Perna perna utilizando o ensaio do tempo de retenção do corante vermelho neutro, que avalia a estabilidade da membrana lisossômica de hemócitos dos organismos teste. A Amoxicilina causou citotoxicidade aos mexilhões nas concentrações de: CEO: 1 ng.L-1, CI25-24h: 0,44 ng.L-1, CI25-48h: 1,19 ng.L-1 e CI25-72h: 0,85 ng.L-1, o Clavulanato de Potássio foi citotóxico nas concentrações de: 10 ng.L-1 em 24h e 50 ng.L-1 e 100 ng.L-1 em 48h e 72h. Os valores de concentração inibitória foram de CI25-24h: 3,11 ng.L-1, CI25-48h: 3,45 ng.L-1 e CI25-72h: 3,43 ng.L-1. No ensaio realizado com a associação dos fármacos todas as concentrações foram citotóxicas aos mexilhões em 48h e em 72h apenas 40 ng.L-1 de Amoxicilina + 10 ng.L-1 de Clavulanato de Potássio e 200 ng.L-1 de Amoxicilina + 50 ng.L-1 de Clavulanato de Potássio. As concentrações inibitórias foram: CI25-48h: 1,67 ng.L-1 e CI25-72h: 1,36 ng.L-1 a partir dos dados de Amoxicilina e CI25-48h: 0,42 ng.L-1 e CI25-72h: 0,34 ng.L-1 a partir dos dados de Clavulanato de Potássio. / Pharmaceutical compounds are identified in environmental matrices in orders of magnitude from ng.L-1 to &mu;g.L-1. Among the drugs, antibiotics have received special attention due to the problems that can cause to aquatic biota. The aim of this study was to evaluate the cytotoxicity of Amoxicillin and Potassium Clavulanate in isolated and associated forms to marine mussels Perna perna through the neutral red retention time assay which assesses the stability of hemocytes lisossomal membrane of test organisms. Amoxicillin caused cytotoxicity to the mussels in concentrations of: OEC: 1 ng.L-1, IC25-24h: 0.44 ng.L-1, IC25- 48h: 1.19 ng.L-1 and IC25-72h: 0.85 ng.L-1, Potassium Clavulanate was cytotoxic at concentrations of 10 ng.L-1 in 24h; 50 ng.L-1 and 100 ng.L-1 at 48h and 72h. The inhibitory concentration values were IC25-24h: 3.11 ng.L-1, IC25-48h: 3.45 ng.L-1 and IC25-72h: 3.43 ng.L- 1. The test conducted with the combination of drugs all concentrations were cytotoxic to mussels in 48h and 72h only 40 ng.L-1 Amoxicillin + 10 ng.L-1 and Potassium Clavulanate 200 ng.L-1 Amoxicillin + 50 ng.L-1 Potassium Clavulanate. The inhibitory concentrations were IC25-48h: 1.67ng.L-1 and IC25-72h: 1.36 ng.L-1 from the data of Amoxicillin and IC25- 48h: 0.42 ng.L-1 and IC25-72h: 0.34 ng.L-1 from the Potassium Clavulanate data.