Sergio Nascimento Duarte

Fetal cystoscopy for severe lower urinary tract obstruction—initial experience of a single center

To report the experience with fetal cystoscopy and laser fulguration of posterior urethral values (PUV) for severe lower urinary tract obstruction (LUTO).

Destinação de águas residuárias provenientes do processo de dessalinização por osmose reversa

Nos ultimos anos, inumeros aparelhos de dessalinizacao por osmose reversa foram instalados no Brasil, sobretudo na Regiao Nordeste, onde se tem, historicamente, graves problemas economicos e sociais devido a escassez de agua. A dessalinizacao das aguas pode constituir-se em uma ferramenta concreta de desenvolvimento regional no semi-arido do Nordeste brasileiro; entretanto, e necessario que se considerem os riscos ambientais decorrentes, isto porque, na dessalinizacao se gera, alem da agua potavel, uma agua residuaria (rejeito), altamente salina e de poder poluente elevado. No presente texto sao revisados trabalhos conduzidos no Brasil e em outros paises, os quais utilizam diversas alternativas para a destinacao e o uso deste rejeito.

Combination of fresh and brackish waters for hydroponic lettuce production

Plantas de alface crespa cv. Veronica foram cultivadas em condicao hidroponica objetivando-se avaliar dois tipos de emprego combinado de aguas doce e salobras, quais sejam: usar as aguas salobras para preparar a solucao nutritiva (SN) e a agua doce para repor a evapotranspiracao da cultura (ETc) (Experimento I) e usar a agua doce para preparar a SN e as salobras para a reposicao da ETc (Experimento II). Uma estrutura de pesquisa com 40 parcelas que simulam a tecnica do fluxo laminar de nutrientes (NFT) foi construida. Os niveis de salinidade da agua testados foram: 0,585; 1,17; 1,755; 2,925 e 4,095 g L-1 de NaCl. A salinidade diminuiu a produtividade da alface (massa de materia fresca da parte aerea) em 10,9 e 3,91% para cada acrescimo unitario na salinidade da agua (g L-1 de NaCl), considerando-se os Experimentos I e II, respectivamente. De acordo com os resultados obtidos com os dois tipos de combinacao de aguas doce e salobras, o uso de aguas salobras para repor a ETc pode aumentar a produtividade da alface em comparacao com o uso dessas aguas para preparar a SN.

Percutaneous Laser Ablation of Sacrococcygeal Teratoma in a Hydropic Fetus with Severe Heart Failure - Too Late for a Surgical Procedure?

Sacrococcygeal teratoma (SCT) is the commonest solid fetal tumor. Perinatal prognosis is usually favorable, but sometimes it can be complicated by fetal hydrops being responsible for high risk of mortality. Fetal therapy in such cases has so far not been established. We report a case with a giant solid SCT associated with fetal hydrops and severe heart failure. 2D- and 3D-Doppler ultrasonography revealed great vessels originated from the medial sacral artery. Percutaneous laser ablation of these vessels was performed at 24 weeks of gestation. During the procedure, severe anemia was also diagnosed (hemoglobin 4.3 g/dl). Two days later, the fetus died and pathological examination revealed local tumor necrosis and blood hemorrhage inside the mass. We suggest that in such cases, fetal surgery may not be enough, being too late, and perhaps fetal clinical therapy for anemia and heart failure could be the best option at a gestational age of less than 28 weeks.

Tolerance of cucumber crop to salinity in greenhouse

The objective of this work was to evaluate the cucumber crop in saline conditions resulting from fertilizer salt, under six levels of soil salinity (1.5, 2.5, 3.5, 4.5, 5.5 and 6.5 dS m-1). The study was carried out in the experimental area of the Department of Rural Engineering of the ESALQ/USP, Piracicaba/SP, Brazil. The planting was carried out in recipients using sandy soil during the period of 28/08/07 to 20/10/07. As the main results, it was verified that the maximum productivity was 2.45 kg m-2 for the salinity level of 3.5 dS m-1, that with the values of relative production the threshold salinity (SL) observed was of 4.08 dS m-1, and that there was a decline of 19.33% in production for unit increase of soil salinity above the threshold point.

Manejo da fertirrigação e controle da salinidade do solo sob ambiente protegido, utilizando-se extratores de solução do solo

Com o objetivo de avaliar o uso de extratores de solucoes do solo no auxilio ao manejo da fertirrigacao e no controle da salinidade em solo cultivado com melao rendilhado, conduziu-se um estudo em ambiente protegido na area experimental do Departamento de Engenharia Rural da ESALQ/USP, localizada no municipio de Piracicaba, SP. Os tratamentos se compunham da combinacao de dois fatores: 6 niveis de salinidade inicial do solo (S1 = 1,0; S2 = 2,0; S3 = 3,0; S4 = 4,0; S5 = 5,0 e S6 = 6,0 dS m-1) e dois manejos de fertirrigacao: tradicional e com controle da condutividade eletrica da solucao do solo. Procedeu-se a salinizacao inicial do solo por meio da aplicacao de solucoes salinas preparadas a partir de fertilizantes, em que a quantidade de sais a ser adicionada foi determinada tomando-se por base uma curva de salinizacao artificial, obtida previamente em laboratorio. Os resultados mostraram que, com o uso de extratores de solucao do solo, pode-se monitorar a concentracao ionica da solucao do solo, com precisao satisfatoria. A salinidade do solo evoluiu com o tempo, estando os maiores niveis proximos a superficie do solo e do gotejador. A diferenca no consumo de agua entre os niveis de salinidade foi mais evidenciada no manejo controlado da fertirrigacao, ajustando-se a um modelo quadratico.

CURVAS DE DISTRIBUIÇÃO DE EFLUENTES DO ÍON NITRATO EM AMOSTRAS DE SOLO DEFORMADAS E INDEFORMADAS 1

There is a great importance to quantify the trace and the chemical elements transport in soil. This work had as objective to obtain the transport parameters of the nitrate ion in soil (pore water velocity (v), retardation factor (R), dispersivity (λ) and the dispersion coefficient (D)) in different textures soils, mainly, under different sampling forms (deformed and non deformed). The research was carried out under two samplings forms, mentioned previously, by application of 50 mg L -1 of NO3 - in two different soils profiles at a depth of 0-20 cm. The breakthrough curves was made by two forms: traditional methodology (TFSA) and the technique with non deformed sample developed during the research period. The results showed that the transport parameters fitted by the computational program CXTFIT, with deformed sampling, overestimated the parameters values, with exception of dispersivity, when compared to the non deformed sampling, for both soil types.

Modelo para simulação da dinâmica de nitrato em colunas verticais de solo não saturado

A agricultura intensiva esta sempre em busca de incrementos de produtividade mas, em contrapartida, pouca atencao e dedicada a possiveis impactos ambientais. Portanto, o entendimento sobre processos de transporte de solutos no solo auxilia na reducao da sua lixiviacao para as camadas subsuperficiais. Neste sentido, objetivou-se, com o presente trabalho, desenvolver e avaliar um modelo computacional aplicado para simulacao da dinâmica de solutos no solo por meio de solucoes numericas de equacoes diferenciais que descrevam esse transporte. Pelos resultados obtidos, o modelo apresentou bom ajuste das concentracoes de nitrato e dos perfis de umidade, simulados com relacao aos medidos em condicoes de laboratorio em coluna vertical de solo nao saturado.

Porous ceramic cup extractors to monitor electric conductivity and potassium levels in soil solution

The objective of this work was to evaluate porous ceramic cups to observe electric conductivity and potassium concentration in soil solution. An area cultivated with tomatoes under fertirrigation with three potassium levels and application frequencies of one and three days, was used. Values for electric conductivity and K concentration were corrected for moisture using saturated pastes as a function of different soil moistures. Values for electric conductivity obtained with porous ceramic cups underestimated by approximately 16% these characteristics measured in the saturation paste extract. The same tendency was observed in the K concentrations, being underestimated by approximately 10%. Coefficients of variation (R2) were greater by 0.7 for the two analyzed variables. Results showed that electric conductivity and K concentration can be analyzed through the solution extractors with an acceptable precision.

Calibração de extratores providos de cápsula porosa para monitoramento da salinidade e da concentração de íons

The satisfactory results obtained in monitoring soil salinity and ion concentration, by means of porous ceramic cup extractors, motivated the realization of this study, which objective was obtaining calibration curves for these extractors to monitor soil electrical conductivity and concentration of nitrate and potassium in two different soils. The nitrate concentrations tested were the same for the two soils (0; 84; 168; 252; 336; 420 and 504 mg L-1) but, for potassium, different concentrations were used for sandy soil (0; 117; 234; 351; 468; 585 and 702 mg L-1) and clay soil (0; 117; 234; 351; 468; 585; 702; 1,170; 1,755; 2,340; 2,925 and 3,510 mg L-1). Electrical conductivity of soil solution and concentrations of nitrate and potassium were estimated with satisfactory precision from soil solution collected with porous ceramic cup extractors, but this task must be preceded by a calibration for each soil type.