Rapid automated method for on-site determination of sulfadiazine in fish farming: a stainless steel veterinary syringe coated with a selective membrane of PVC serving as a potentiometric detector in a flow-injection-analysis system

Sulfadiazine is an antibiotic of the sulfonamide group and is used as a veterinary drug in fish farming. Monitoring it in the tanks is fundamental to control the applied doses and avoid environmental dissemination. Pursuing this goal, we included a novel potentiometric design in a flow-injection assembly. The electrode body was a stainless steel needle veterinary syringe of 0.8-mm inner diameter. A selective membrane of PVC acted as a sensory surface. Its composition, the length of the electrode, and other flow variables were optimized. The best performance was obtained for sensors of 1.5-cm length and a membrane composition of 33% PVC, 66% onitrophenyloctyl ether, 1% ion exchanger, and a small amount of a cationic additive. It exhibited Nernstian slopes of 61.0 mV decade-1 down to 1.0×10-5 mol L-1, with a limit of detection of 3.1×10-6 mol L-1 in flowing media. All necessary pH/ionic strength adjustments were performed online by merging the sample plug with a buffer carrier of 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, pH 4.9. The sensor exhibited the advantages of a fast response time (less than 15 s), long operational lifetime (60 days), and good selectivity for chloride, nitrite, acetate, tartrate, citrate, and ascorbate. The flow setup was successfully applied to the analysis of aquaculture waters. The analytical results were validated against those obtained with liquid chromatography–tandem mass spectrometry procedures. The sampling rate was about 84 samples per hour and recoveries ranged from 95.9 to 106.9%.

Nonlinear Dynamics for Local Fractional Burgers Equation Arising in Fractal Flow

The local fractional Burgers’ equation (LFBE) is investigated from the point of view of local fractional conservation laws envisaging a nonlinear local fractional transport equation with a linear non-differentiable diffusion term. The local fractional derivative transformations and the LFBE conversion to a linear local fractional diffusion equation are analyzed.

Mathematical modelling of shallow flows: closure models drawn from grain-scale mechanics of sediment transport and flow hydrodynamics

Canadian Journal of Civil Engineering 36(10) 1605–16

Effects of Soil Compaction and Organic Carbon Content on Preferential Flow in Loamy Field Soils

Abstract: Preferential flow and transport through macropores affect plant water use efficiency and enhance leaching of agrochemicals and the transport of colloids, thereby increasing the risk for contamination of groundwater resources. The effects of soil compaction, expressed in terms of bulk density (BD), and organic carbon (OC) content on preferential flow and transport were investigated using 150 undisturbed soil cores sampled from 15 × 15–m grids on two field sites. Both fields had loamy textures, but one site had significantly higher OC content. Leaching experiments were conducted in each core by applying a constant irrigation rate of 10 mm h−1 with a pulse application of tritium tracer. Five percent tritium mass arrival times and apparent dispersivities were derived from each of the tracer breakthrough curves and correlated with texture, OC content, and BD to assess the spatial distribution of preferential flow and transport across the investigated fields. Soils from both fields showed strong positive correlations between BD and preferential flow. Interestingly, the relationships between BD and tracer transport characteristics were markedly different for the two fields, although the relationship between BD and macroporosity was nearly identical. The difference was likely caused by the higher contents of fines and OC at one of the fields leading to stronger aggregation, smaller matrix permeability, and a more pronounced pipe-like pore system with well-aligned macropores.

Information flow analysis using data-dependent logical propositions

Dissertação para obtenção do Grau de Mestre em Engenharia Informática

LATERAL FLOW ASSAY FOR CRYPTOCOCCAL ANTIGEN: AN IMPORTANT ADVANCE TO IMPROVE THE CONTINUUM OF HIV CARE AND REDUCE CRYPTOCOCCAL MENINGITIS-RELATED MORTALITY

SUMMARYAIDS-related cryptococcal meningitis continues to cause a substantial burden of death in low and middle income countries. The diagnostic use for detection of cryptococcal capsular polysaccharide antigen (CrAg) in serum and cerebrospinal fluid by latex agglutination test (CrAg-latex) or enzyme-linked immunoassay (EIA) has been available for over decades. Better diagnostics in asymptomatic and symptomatic phases of cryptococcosis are key components to reduce mortality. Recently, the cryptococcal antigen lateral flow assay (CrAg LFA) was included in the armamentarium for diagnosis. Unlike the other tests, the CrAg LFA is a dipstick immunochromatographic assay, in a format similar to the home pregnancy test, and requires little or no lab infrastructure. This test meets all of the World Health Organization ASSURED criteria (Affordable, Sensitive, Specific, User friendly, Rapid/robust, Equipment-free, and Delivered). CrAg LFA in serum, plasma, whole blood, or cerebrospinal fluid is useful for the diagnosis of disease caused by Cryptococcusspecies. The CrAg LFA has better analytical sensitivity for C. gattii than CrAg-latex or EIA. Prevention of cryptococcal disease is new application of CrAg LFA via screening of blood for subclinical infection in asymptomatic HIV-infected persons with CD4 counts < 100 cells/mL who are not receiving effective antiretroviral therapy. CrAg screening of leftover plasma specimens after CD4 testing can identify persons with asymptomatic infection who urgently require pre-emptive fluconazole, who will otherwise progress to symptomatic infection and/or die.

Membrane structural changes support the involvement of mitochondria in the bile salt-induced apoptosis of rat hepatocytes

Clin Sci (Lond). 2002 Nov;103(5):475-85

Hepatic Artery Thrombosis in Live Liver Donor Transplantation: How to Solve - a Case Report

The decrease in the number of cadaveric donors has proved a limiting factor in the number of liver transplants, leading to the death of many patients on the waiting list. The living donor liver transplantation is an option that allows, in selected cases, increase the number of donors. One of the most serious complications in liver transplantation is hepatic artery thrombosis, in the past considered potentially fatal without urgent re-transplantation. A white male patient, 48 years old, diagnosed with hepatocellular carcinoma in chronic liver failure caused by hepatitis B virus, underwent living donor liver transplantation (right lobe). Doppler echocardiography performed in the immediate postoperative period did not identify arterial flow in the right branch, having been confirmed thrombosis of the right hepatic artery in CT angiography. Urgent re-laparotomy was performed, which consisted of thrombectomy and re-anastomosis of the hepatic artery with segmental splenic artery allograft interposition. The patient started anticoagulation and antiplatelet therapy with acetylsalicylic acid. Serial evaluation with Doppler echocardiography showed hepatic artery patency. At present, the patient is asymptomatic. One of the most devastating complications in liver transplantation, and particularly in living liver donor, is thrombosis of the hepatic artery; thus, early diagnosis and treatment is vital. The rapid intervention for revascularization of the graft avoids irreversible ischemia of the bile ducts and hepatic parenchyma, thus avoiding the need for re-transplantation.

Pesquisa de bactérias, fungos, protozoários e cristais em bile vesicular

Os autores estudaram 40 vesículas e bile de cadáveres e 23 de portadores de colecistopatia que se submeteram à cirurgia; procuraram averiguar o percentual de positividade para bactérias, fungos, cristais e cálculos, para uma possível avaliação de etioloqia das colecistopaUas. Encontraram um elevado percentual de cristais - 60% em cadáveres e 63% em vesículas cirúrgicas -, e um baixo índice de fungos - 2,5% em cadáveres e 0% em bile vesicular cirúrgica. Dos 23 casos cirúrgicos, encontraram 13% de biles infectadas por bactérias e 50% em cadáveres que nunca referiram, em vida, qualquer sintoma que fizesse suspeitar colecistopatia.

Does direct cash flow presentation help in predicting future operating cash flow?

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics

Weekly tracking of stability of the flow of conversations into the subprocesses of the Last Planner System

21st Annual Conference of the International Group for Lean Construction – IGLC 21 – Fortaleza, Brazil

Flow cytometric quantitation of phagocytosis in heparinized complete blood with latex particles and Candida albicans

We report a rapid method for the flow cytometric quantitation of phagocytosis in heparinized complete peripherial blood (HCPB), using commercially available phycoerythrin-conjugated latex particles of 1µm diameter. The method is faster and shows greater reproducibility than Bjerknes' (1984) standard technique using propidium iodide-stained Candida albicans, conventionally applied to the leukocytic layer of peripherial blood but here modified for HCPB. We also report a modification of Bjerknes' Intracellular Killing Test to allow its application to HCPB.

Significance of bile-duct changes in schistosomiasis

Lesions involving the intra-hepatic biliary ducts in schistosomiasis have been reported in the literature, both in mice and man, but there are no data concerning their quantitative, evolutionary or post curative chemotherapeutic aspects on record. In order to obtain such data an investigation on this subject was attempted. Mice infected with 50 Schistosoma mansoni cercariae were submitted to a liver biopsy at the 9th week post-infection, and treated with 400mg/bw praziquantel immediately afterwards. Infected and non-infected controls were submitted to the same procedures. By 19 weeks from cercarial exposure all surviving animals were sacrificed. The biliary ducts were counted on histological sections and the results were expressed as biliary ducts/portal spaces. This quantitative evaluation was compared with that from normal controls and revealed hyperplasia as the main biliary duct change (p<0.007) in schistosomiasis. Hyperplastic changes underwent only mild partial and not statistically significant regression after specific chemotherapy (p>0.05). Infected and untreated animals presented ductal changes that did not differ from those of the treated group. Measurements of serum bilirrubin (total and direct), and gamma-glutamyl-transpeptidase (gamma-GT) did not reveal significant differences when animals from the several groups were compared. Thus, bile ducts exhibit a proliferative response in relation to neighboring S. mansoni injury to portal areas, but although these lesions are histopathologically impressive, they lack a functional or prognostic significance.

Detection of Mycobacterium leprae infection in wild nine-banded armadillos (Dasypus novemcinctus) using the rapid ML Flow test

Mycobaterium leprae infection was investigated in armadillos from the State of Espírito Santo, Brazil. The ML Flow test was performed on 37 nine-banded armadillos and positive results were found in 11 (29.7%). The ML Flow test may be used to identify possible sources of Mycobaterium leprae among wild armadillos.