RESUMO
The present study analyzed the performance of photochemical and electrochemical techniques in the degradation and mineralization of the pesticide carbendazim (CBZ). Direct photolysis (DP), heterogeneous photocatalysis (HP), photoelectrocatalysis (PEC), and electrochemical oxidation (EO) were tested, and the influence of UV radiation, current density (j), and supporting electrolyte concentration were evaluated. The results suggest that CBZ is only degraded by DP when UV-C254nm is used. For HP, the CBZ degradation was observed both when UV-A365nm or UV-C254nm were used, which is related to the reactive oxygen species (ROS) formed by the photocatalytic activity (photon-ROS). Neither DP nor HP were able to mineralize CBZ, demonstrating its resistance to photomediated processes. For EO, regardless of the j, there were higher CBZ degradation and mineralization than those observed when using DP and HP. The increase in the supporting electrolyte concentration (Na2SO4) did not affect the levels of degradation and mineralization of CBZ. Concerning the PEC, a CBZ mineralization of 52.2% was accomplished. These findings demonstrate that the EO is the main pathway for CBZ mineralization, suggesting an additional effect of the electro-ROS on the photon-ROS and UV-C254nm. The values of mineralization, kinetics, and half-life show that PEC UV-C254nm with a j of 15 mA cm-2 was the best setting for the degradation and mineralization of CBZ. However, when the values of specific energy consumption were considered for industrial applications, the use of EO with a j of 3 mA cm-2 and 4 g L-1 of Na2SO2 becomes more attractive. The assessment of by-products formed after this best cost-efficient treatment setting revealed the presence of aromatic and aliphatic compounds from CBZ degradation. Acute phytotoxicity results showed that the presence of sodium sulfate can be a representative factor regarding the toxicity of samples treated in electrochemical systems.
Assuntos
Poluentes Químicos da Água , Benzimidazóis , Carbamatos , Oxirredução , Fotólise , Raios Ultravioleta , Poluentes Químicos da Água/químicaRESUMO
This work aims to present different electroreduction and electrocatalytic processes configurations to treat nitrate contaminated water. The parameters tested were: current density, cell potential, electrode potential, pH values, cell type and catalyst use. It was found that the nitrite ion is present in all process variations used, being the resulting nitrite concentration higher in an alkaline pH. The increase in current density on galvanostatic operation mode provides a greater reduction of nitrate (64%, 1.4 mA cm-2) if compared to the potentiostatic (20%) and constant cell potential (37%) configurations. In a dual-chamber cell the nitrate reduction with current density of 1.4 mA cm-2 was tested and obtained as a NO3- reduction of 85%. The use of single chamber cell presented 32 ± 3% of nitrate reduction, indicating that in this cell type the nitrate reduction is smaller than in dual-chamber cell (64%). The presence of a Pd catalyst with 3.1% wt. decreased the nitrite (1.0 N-mg L-1) and increased the gaseous compounds (9.4 N-mg L-1) formation. The best configuration showed that, by fixing the current density, the highest nitrate reduction is obtained and the pH presents a significant influence during the tests. The use of the catalyst decreased the nitrite and enhanced the gaseous compounds formation.
Assuntos
Nitratos , Nitritos , Cobre , Eletrodos , Óxidos de NitrogênioRESUMO
In order to determine the analgesic and cardiovascular effects of the combination of epidural ketamine and lidocaine, 6 sedated cats were studied. Six healthy, young cats were used in a prospective randomised study. Each cat underwent 3 treatments, at least 1 week apart, via epidural injection: (1) ketamine (2.5 mg/kg), (2) lidocaine (4.0 mg/kg), and (3) ketamine (2.5 mg/kg) plus lidocaine (4.0 mg/kg). Epidural injections were administered through the lumbosacral space. Analgesia, motor block, sedation, heart rate, arterial blood pressure, respiratory rate and arterial oxygen saturation were measured. Rectal temperature was compared before and after sedation as well as after epidural administration of the drugs. Epidural administration of the ketamine/lidocaine combination induced prolonged analgesia extending from the coccygeal to the T13-L1 dermatomes, leading to severe ataxia. Cardiovascular effects were significant in all treatments: heart rate decreased, but there was a minimal reduction in arterial pressure. It was concluded that adding a dose of ketamine to epidural lidocaine in cats is feasible and effective.
Assuntos
Analgesia Epidural/veterinária , Analgésicos/administração & dosagem , Anestésicos Locais/administração & dosagem , Gatos/fisiologia , Ketamina/administração & dosagem , Lidocaína/administração & dosagem , Agonistas alfa-Adrenérgicos/administração & dosagem , Animais , Estudos Cross-Over , Combinação de Medicamentos , Frequência Cardíaca/fisiologia , Bloqueio Nervoso/veterinária , Estudos Prospectivos , Xilazina/administração & dosagemRESUMO
In this study different membranes were produced, aiming to evaluate their use in electrodialysis. These membranes were produced using conventional polymer (high-impact polystyrene) and polyaniline. The membrane characterization was done by FTIR spectroscopy, scanning electron microscopy (SEM), and thermogravimetry (TGA). The studies of the zinc and proton extraction ionic transport through the membranes were evaluated using a three-compartment cell. The results obtained using the produced membranes were compared to the results obtained with the commercial membrane Nafion 450. It was found that a synthesized membrane can be used to recover zinc in acid media. In addition, a preliminary computational essay about the structures of PAni and CSA is presented.
RESUMO
The present study deals with the purification of spent chromium bath contaminated by trivalent chromium, iron and aluminum. The ionic transfer of Fe(III) depends on the presence of chloride ions on the pH while aluminum transfer is not affected by chromium(III) chloride. Five different commercial cation-exchange membranes were used. Nafion and PC-SK membranes showed the best results for trivalent iron and aluminum transfer.
Assuntos
Cromo/isolamento & purificação , Eletroquímica/métodos , Membranas Artificiais , Poluentes Químicos da Água/isolamento & purificaçãoRESUMO
The study aimed to determine the continuous rate infusion of tramadol associated with peri- and postoperative analgesia for orthopedic surgeries in dogs, as well as cardiorespiratory and adverse effects. Thirty dogs aged 4.2±1.2 years and weighing 15.1±0.9kg were enrolled in the study, premedicated intramuscularly with acepromazine (0.04mg kg-1) and tramadol (2mg kg-1); anesthesia was induced with propofol and maintained with isoflurane in oxygen. Three infusion rates were compared, comprising three experimental groups: G2: 2.0mg kg-1 h-1; G2.5: 2.5mg kg-1 h-1; and G3: 3.0mg kg-1 h-1. Surgery was initiated 15 minutes following the start of tramadol infusion. During anesthesia, animals were monitored in predefined time points: immediately after tracheal intubation and start of inhalation anesthesia (T0); surgical incision (TSI); final suture (TFS) and end of tramadol infusion (TEI), which was maintained for at least 120 minutes and prolonged according to the duration of surgery. Postoperative analgesia was evaluated through an interval pain scoring scale and the Melbourne pain scale. The mean time of tramadol infusion was greater than 120 minutes in all groups and no differences were found among them (141±27 minutes in G2, 137±27 minutes in G2.5 and 137±30 minutes in G3). Perioperative analgesia was regarded as short and did not correlate with infusion rates. Tramadol infusion provided adequate analgesia with cardiorespiratory stability Analgesia was not dose-dependent, however, and residual postoperative effects were short-lasting, which warrants proper postoperative analgesia following tramadol infusion. Additional studies are required using higher infusion rates and standardized nociceptive stimulation in order to determine how doses influence tramadol analgesia and whe therthereis a limit to its effect in dogs.(AU)
Objetivou-se determinar a infusão de taxa contínua de tramadol associada à analgesia peri e pós-operatória para cirurgias ortopédicas em cães, além de efeitos cardiorrespiratórios e adversos. Foram utilizados 30 cães, com idade média de 4,2±1,2 anos e pesos médios de 15,1±0,9kg, pré-medicados por via intramuscular com acepromazina (0,04mg/kg) e tramadol (2mg/kg). A anestesia foi induzida com propofol e mantida com isoflurano em oxigênio. Foram comparadas três taxas de infusão, compreendendo três grupos experimentais: G2: 2,0mg/kg; G2,5: 2,5mg/kg1; e G3: 3,0mg/kg. A cirurgia começou 15 minutos após o início da infusão de tramadol. Durante a anestesia, os animais foram monitorados nos seguintes momentos: imediatamente após a intubação traqueal e o início da anestesia inalatória (T0); incisão cirúrgica (TSI); final de sutura (TFS) e final da infusão de tramadol (TEI), que foi mantida por, pelo menos, 120 minutos e prolongada de acordo com a duração da cirurgia. A analgesia pós-operatória foi avaliada por escalas de pontuação de dor, conforme a escala intervalar de avaliação de dor e a escala de contagem variável de avaliação de dor da Universidade de Melbourne, a cada uma hora. O tempo médio de infusão de tramadol foi maior que 120 minutos em todos os grupos, e não foram encontradas diferenças entre elas (141±27 minutos em G2, 137±27 minutos em G2,5 e 137±30 minutos em G3). A analgesia perioperatória foi adequada na maioria dos indivíduos e a pós-operatória foi considerada curta, não correlacionada àquelas com diferentes taxas de infusão. A infusão de tramadol nas taxas estudadas produziu analgesia adequada com estabilidade cardiorrespiratória. A analgesia não foi dose dependente, no entanto os efeitos residuais pós-operatórios foram considerados curtos, o que determina a necessidade de analgesia adequada após infusão contínua de tramadol. Estudos adicionais que utilizam taxas mais elevadas de infusão de tramadol e estimulação nociceptiva padrão são necessários para determinar em que medida as doses influenciam a analgesia de tramadol e se há um limite nos seus efeitos nos cães.(AU)
Assuntos
Animais , Cães , Tramadol/análise , Cães/cirurgia , Anestesia Geral/estatística & dados numéricosRESUMO
The aim of this study was to assess the cardiopulmonary, analgesic, adverse effects, serum concentration of cortisol and plasma levels of levobupivacaine and morphine in bitches undergoing propofol anesthesia and epidural analgesia with levobupivacaine alone or combined with morphine. This was a randomized 'blinded' prospective clinical study using 32 adult bitches weighing 9.8±4.1kg that were admitted for elective ovariohysterectomy. Twenty minutes after administration of acepromazine and midazolam, anesthesia was induced with propofol (4mg kg-1) and maintained by a continuous rate infusion (CRI). Each animal was randomly assigned to one of four epidural groups: GL = levobupivacaine alone (0.33mg kg-1); GLM0.1 = levobupivacaine and morphine (0.1mg kg-1); GLM0.15 = levobupivacaine and morphine (0.15mg kg-1); and GLM0.2 = levobupivacaine and morphine (0.2mg kg-1)...
Objetivou-se avaliar os efeitos cardiovasculares, analgésico, adversos, a concentração sérica de cortisol e os níveis plasmáticos de levobupivacaína e morfina em cadelas submetidas à infusão contínua de propofol e analgesia peridural com levobupivacaína isolada ou associada à morfina. Para tanto, realizou-se um estudo clínico prospectivo randomizado com 32 cadelas adultas pesando 9,8 ± 4,1kg, que foram submetidas à ovário-histerectomia eletiva. Vinte minutos após a administração de acepromazina e midazolam, os animais foram induzidos com propofol (4mg/kg) e mantidos por uma infusão contínua (CRI) do mesmo fármaco. Cada animal foi alocado aleatoriamente em um dos quatro grupos: GL = levobupivacaína isolada (0,33mg/kg); GLM0,1 = levobupivacaína + morfina (0,1mg/kg); GLM0,15 = levobupivacaína + morfina (0,15mg/kg) e GLM0,2 = levobupivacaína + morfina (0,2mg/kg)...
Assuntos
Animais , Cães , Anestesia Epidural/efeitos adversos , Anestesia Epidural/veterinária , Hidrocortisona/efeitos adversos , Morfina/efeitos adversos , Propofol/administração & dosagem , Propofol/análise , Anestésicos Locais , Analgésicos Opioides/análise , Analgésicos Opioides/efeitos adversos , Ovariectomia/veterináriaRESUMO
O presente estudo investigou os benefícios da anestesia por tumescência com lidocaína em cadelas submetidas à mastectomia, visando ao conforto do paciente e à sua recuperação pós-operatória. Foram utilizados sete animais, de peso e raças variadas, que apresentavam neoplasia em região de cadeia mamária e que foram submetidos à cirurgia de mastectomia. Todos os animais receberam o mesmo protocolo anestésico, sendo utilizado como MPA a associação entre acepromazina e morfina, nas doses de 0,04mg/kg e 0,4mg/kg (IM), respectivamente. Após 15 minutos, foi alocado um cateter em veia cefálica e realizou-se a indução com propofol 4mg/kg e midazolam 0,2mg/kg, seguida de manutenção anestésica com isofluorano. Posteriormente à instrumentação, procedeu-se à técnica de anestesia por tumescência com solução gelada composta por ringer lactato, lidocaína 2% sem vasoconstritor e adrenalina, em um volume total de 15mL/kg. Em média, o tempo de duração do procedimento foi de 74±18 minutos. O pico plasmático de lidocaína deu-se entre 30 e 60 minutos após a infiltração da solução. O resgate analgésico foi realizado após sete horas, aproximadamente, da infiltração. Pode-se concluir que a anestesia por tumescência com lidocaína deve ser considerada como constituinte do protocolo anestésico e analgésico de cadelas a serem submetidas à cirurgia de mastectomia, proporcionando estabilidade de parâmetros, segurança e recuperação pós-operatória de boa qualidade.
The present study investigated the benefits of tumescent anesthesia with lidocaine in dogs undergoing mastectomy, seeking the patients' comfort and their postoperative recovery. Seven animals, with different weight and breed, who had cancer in the region of mammary chain underwent mastectomy surgery. All animals received the same anesthetic protocol being used as the association between acepromazine and morphine doses of 0.04mg.kg-1 and 0.4mg.kg-1 (IM), respectively. After 15 minutes a catheter was placed in the cephalic vein and induction with propofol 4mg.kg-1 and 0.2mg.kg-1 followed by maintenance with isoflurane anesthesia was done. After instrumentation, we proceeded to the tumescent anesthesia technique with ice-cold solution consisting of Ringer's lactate, lidocaine 2% without epinephrine and adrenaline in a total volume of 15mL.kg-1. The average duration of the procedure was 74±18 minutes. The plasmatic peak of lidocaine was between 30 and 60 minutes after infiltration. The rescue analgesic was performed after approximately seven hours of infiltration. It can be concluded that the tumescent anesthesia with lidocaine should be considered as a constituent of anesthetic and analgesic protocol in dogs undergoing mastectomy surgery providing parameter stability, safety and good quality postoperative recovery.
Assuntos
Animais , Feminino , Cães , Anestesia Local , Anestesia Local/veterinária , Mastectomia/veterinária , Neoplasias/veterinária , Lidocaína/efeitos adversos , Lidocaína/toxicidadeRESUMO
Avaliaram-se os períodos de latência e de duração do efeito do butorfanol associado à ropivacaína aplicados pela via peridural e a possibilidade de uso dessa associação como protocolo anestésico para realização de ovariossalpingo-histerectomia (OSH) em cadelas. Utilizaram-se 16 cadelas pré-medicadas com acepromazina e midazolam compondo dois grupos: no grupo 1 (n=8) aplicou-se ropivacaína isolada (0,3mL/kg) e no grupo 2 (n=8), butorfanol (0,1mg/kg) e ropivacaína (até o volume de 0,3mL/kg), pela via peridural. Consideraram-se nove momentos (M): M0 - animal sem anestesia, M1 - 15 minutos após medicação pré-anestésica; M2 - 30 minutos após a aplicação peridural; M3, M4 e M5 - correspondentes ao início do procedimento e ao pinçamento dos pedículos esquerdo e direito, respectivamente; M6 - ligadura da cérvix uterina; e M7 e M8 - início da laparorrafia e fim da sutura de pele, respectivamente. Foram avaliados os períodos de latência e ação do bloqueio, além da viabilidade de realização do procedimento cirúrgico por meio do bloqueio efetuado. O que recebeu ropivacaína + butorfanol apresentou sedação pronunciada e permitiu a realização de OSH em 75 por cento dos animais, sem indução anestésica. Não houve diferença entre os grupos quanto aos períodos de latência e duração. A associação do butorfanol à ropivacaína proporcionou bloqueio anestésico compatível com a realização de OSH e período de latência curto, com duração de efeito suficiente para o procedimento cirúrgico.
The periods of latency and duration of butorphanol associated with ropivacaine used via epidural, and this combination as anesthetic protocol for carrying out ovariosalpingohysterectomy (OSH) in bitches were evaluated. Sixteen animals pre-medicated with acepromazine and midazolam were used composing two groups that received: 1 (n=8) ropivacaine (0.3mL/kg) and 2 (n=8) butorphanol (0.1mg/kg) and ropivacaine (up to the volume of 0.3ml/kg) via epidural. Nine moments were studied: M1 - 15 minutes after pre-anesthetic medication; M2 - 30 minutes after the epidural medication; M3, M4, and M5 - at the beginning of surgery and at clamping left and right pedicles, respectively; M6 - at ligation of the uterine cervix; and M7 and M8 - at laparorhaphy and end of skin suture, respectively. Periods of latency and blocking the action of random double-covert manner were evaluated as well as the feasibility of carrying out the surgery performed by the blockade. It was observed that the group receiving ropivacaine + butorphanol allowed the execution of OSH in 75 percent of animals without the need for anesthesia. There was no statistical difference between the periods of latency and duration. It was concluded that the combination of butorphanol to ropivacaine provides, in bitches, block compatible with the implementation of OSH with short period of latency and duration of effect sufficient for the surgical procedure.