Determination of oxygen consumption in water by continuous flow injection analysis using potassium permanganate / 预防医学

Objective@#To establish a continuous flow injection analysis with potassium permanganate for determination of oxygen consumption in water.@*Methods@#The water samples and acid potassium permanganate working solutions were mixed using the continuous flow bubble spacing, and subjected to online heating reaction at 97 ℃. The peak height of the electrical signal of potassium permanganate was measured at the maximum absorption wavelength of 520 nm, and the standard substance, sulfuric acid concentration and potassium permanganate concentration were optimized according to the peak height of the electrical signal. The standard curve was plotted to measure the limit of detection, the limit of quantification, and spiked recovery rate of the method. The CODMn concentration was determined in 40 drinking water samples using acid potassium permanganate titration and continuous flow injection analysis using potassium permanganate, and the determination results of the two methods were compared with paired t-test.@*Results@#Glucose was selected as the standard substance, and the mixture of 17.5% sulfuric acid and 3.2 mmol/L potassium permanganate was selected as the working solution. CODMn had a good linear relationship at concentrations of 0 to 6.00 mg/L, with a correlation coefficient of 0.999 and higher, a detection limit of 0.013 mg/L and a quantitation limit of 0.043 mg/L, respectively. The spiked recovery rates were 90.00% to 105.00% in 40 drinking water samples, with relative standard deviations of 0.12% to 1.36%. The determination results of two permanganate index standard substances were all within the range of standard values. The relative errors of CODMn concentration were 1.55% to 9.26% between the continuous flow injection analysis using potassium permanganate and acid potassium permanganate titration, and there was no significant difference (t=2.023, P=0.185). @*Conclusion@#The established continuous flow injection analysis with potassium permanganate is feasible for batch determination of oxygen consumption in water.

Continuous flow Aza-Michael reaction for preparing the fast-acting synthetic opioid drug Remifentanil

Abstract Remifentanil is a modern fentanyl analogue with ultrashort-action granted by an esterase-labile methyl propanoate chain. Here, we present the development of a continuous flow methodology for the key N-alkylation step of remifentanil preparation in a biphasic, "slug-flow" regime. We screened parameters under microwave-assisted reactions, translated conditions to flow settings, and obtained remifentanil under 15-min residence time in a 1-mL microreactor, with a space-time yield of 89 mg/mL·h and 94% yield.

Determination of cyanide in cassava starch by continuous flow online distillation / 公共卫生与预防医学

Objective To explore the determination of cyanide in cassava starch by a continuous flow online distillation method. Methods Cassava starch was extracted with sodium hydroxide solution, filtered and then quantitatively analyzed with a continuous flow analyzer. The effects of extraction concentration, ultrasonic time, sample size and separation method on cyanide determination were investigated. Results 2.0 g samples were directly weighed and added to 100 mL 2 g/L sodium hydroxide solution for ultrasonic extraction for 20 min, and filtered with qualitative filter paper. The filtrate was quantitatively determined with a continuous flow analyzer. The linear relationship between cyanide concentration of 0 mg/L and 0.20 mg/L was good, r ≥ 0.999. The detection limit of the method was 0.01 mg/kg, the limit of quantitation was 0.03 mg/kg, the relative standard deviation was 0.26%-1.52%, and the standard addition recovery rate was 90.36%-104.19%. Conclusion The continuous flow online distillation method has the advantages of low detection limit, good repeatability, automatic operation, reduction of manual errors, and high analysis speed, which is beneficial to improve work efficiency, and can be used for batch detection of cyanide in cassava starch.

Facilitating noncardiac surgery for the patient with left ventricular assist device: A guide for the anesthesiologist

The introduction of left ventricular assist device (LVAD) has improved survival rates for patients with end-stage heart failure. Two categories of VADs exist: one generates pulsatile flow and the other produces nonpulsatile continuous flow. Survival is better for patients with continuous-flow LVADs. With improved survival, more of such patients now present for noncardiac surgery (NCS). This review, written for the general anesthesiologists, addresses the perioperative considerations when the patient undergoes NCS. For best outcomes, a multidisciplinary approach is essential in perioperative management of the patient.

Ventricular assist device in pediatrics / 中国小儿急救医学

Ventricular assist device ( VAD) is the standard of care for intractable heart failure in adults over the last decade with proven benefit. However,the practice of pediatric VAD has lagged behind that of adult patients. The patient-device mismatch is the major factor that precludes its use in pediatrics. The Berlin EXCOR is the only FDA approved pediatric VAD. The aforementioned armamentarium provides a wide range of size of pump fitting variable body weight and pulsatile ventricular assist device. The VAD is commonly used as a bridge to heart transplantation in children with cardiomyopathy, or in rare instances, bridge to recovery. The VAD support for congenital heart defect is rarely reported and the outcome is poor. The continuous flow ventricular device showed advantages including small size,low incidence of thromboem-bolism and being discharged with device when compared to pulsatile one. So the continuous flow ventricular device is expected to open a new era for the VAD support in pediatrics.

Determination of Nitrate in Seawater with Valve-free Continuous Flow Analysis / 分析化学

A valve-free continuous flow method and instrument were established,with only a multi-channel pump for delivering the sample and reagent,and without any injection or solenoid valves and sample loop for selecting and adding the sample or reagent.Nitrate was reduced to nitrite with Cu-Cd reductant column,and then detected with spectrophotometric detector.The proposed method was suitable for determination of nitrate at normal level in most of estuary and coastal seawaters.With the optimum parameters,the linear range and detection limit were 5-180 μmol/L and 0.27 μmol/L,respectively.The samples of 10 and 80 μmol/L nitrate were continually measured for 11 times,and the relative standard deviations were 1.4％ and 1.3％,respectively.The recovery of real samples at different salinity ranged between 99.4％ and 106.1％.There was no significant difference in the analytical results between the proposed method and the flow injection analysis (FIA).In comparison with FIA,the method and instrument were less cost and easy to operate,and was suitable to be applied in general laboratories and field for continuous monitoring.The method was successfully used to measure the nitrate in seawater samples in Xiamen's Western Harbor and monitor nitrate in Jiulongjiang estuary.

Efficiency of biological treatment for the removal of total and thermotolerant coliform bacteria from domestic sewage / Eficiência do tratamento biológico na remoção de coliformes totais e termotolerantes em esgoto humano

Researchers around the world have focused their efforts on devising combinations of technologies that are not only economically feasible but also effective in mitigating the impacts caused by wastes containing pathogens that pose potential risks to human and animal health. The purpose of this study was to evaluate the performance of a biological treatment system for removing total and thermotolerant coliform bacteria with a view to the possible organic recycling of domestic sewage. To this end, a tubular continuous flow anaerobic digester, with hydraulic retention time (HRT) of 25 days and an optional stabilization pond, were used to treat the sewage produced by 150 people in the municipality of Sertãozinho, SP, Brazil. The samples were collected weekly, always on the same day, at three different sampling points (inlet of the treatment system, the outlet of tubular digester, and the optional stabilization pond), totaling 108 samples. The MPN method was employed to determine the total coliform and thermotolerant coliform populations, using multiple series of three tubes (APHA, 2005). The system proved efficient in reducing the number of indicator bacteria of fecal contamination, showing a removal efficiency of 98.76% for total coliforms and of 99.29% for thermotolerant coliforms. However, a third treatment step involving polishing should be included to render the effluent suitable for use in fertigation or discharge into water bodies.

Aliar tecnologias que sejam viáveis e ainda eficientes em mitigar o impacto gerado pelos resíduos, que possuem potencial patogênico à saúde humana e animal, tem sido o propósito das ações de pesquisadores em todo o mundo. Dessa forma, objetivou-se avaliar um sistema de tratamento biológico, quanto a redução de coliformes totais e coliformes termotolerantes, visando a possibilidade de reciclagem orgânica do esgoto doméstico. Para tanto foi utilizado um biodigestor tubular de fluxo contínuo com tempo de retenção hidráulica (TRH) de 25 dias e uma lagoa de estabilização facultativa, responsável pelo tratamento de esgoto produzido por 150 pessoas, no município de Sertãozinho/SP. As amostras foram colhidas, semanalmente e sempre no mesmo dia, em três pontos distintos de colheita (entrada do sistema de tratamento, saída do biodigestor tubular e na lagoa de estabilização facultativa), totalizando 108 amostras. Para as determinações das populações de coliformes totais e termotolerantes foi utilizada a técnica do NMP em tubos múltiplos série de três tubos (APHA, 2005). O sistema foi eficiente quanto a redução no número de micro-organismos indicadores de poluição fecal atingindo 98,75% para coliformes totais e 99,26% para os termotolerantes. Entretanto, deve ser prevista mais uma etapa para polimento do efluente dando condições para sua utilização na fertirrigação ou lançamento em corpos de água.

Evaluación inicial de parámetros de campo en un biodigestor anaeróbico para el tratamiento de aguas residuales / Preliminary evaluation of field parameters at an anaerobic biodigester designed for the treatment of wastewater

El biodigestor anaerobio utilizado en este estudio, se diseñó para tratar agua residual doméstica en un sanitario de prueba, y se caracteriza por ser de: flujo continuo, baja carga orgánica y tener cuatro etapas de proceso. La importancia del prototipo estudiado radicó en las condiciones reales en que se probó. La primera etapa consistió en la selección del sitio, construcción del prototipo en ferrocemento con capacidad de 1m³, impermeabilización y carga. En esta etapa se inoculó el reactor con materia orgánica procedente de las descargas del sanitario, durante el periodo de agosto a diciembre de 2011. La evaluación de este periodo consistió en la medición de parámetros de campo: pH, conductividad eléctrica, sólidos sedimentables, temperatura del influente - efluente y oxígeno disuelto del sistema que permitieron verificar el comportamiento del proceso del digestor durante la fase de arranque. Los resultados obtenidos para estas determinaciones a la entrada y salida del biodigestor respectivamente son los siguientes: pH (8.03; 8.43), conductividad eléctrica (1510.83 µS/cm; 1207.00 µS/cm), temperatura del proceso (19.2°C; 20.1°C), sólidos sedimentables (144.5mL/L; 0.02mL/L), oxígeno disuelto (4.5992 mg/L; 0.1924 mg/L) estos datos proporcionaron un punto de partida para el tratamiento de aguas residuales de tipo doméstica.

The anaerobic biodigester analyzed in the present study was designed for the treatment of domestic wastewater in a test restroom, characterized by its continuous flow, low organic load and a four-stage processing system. The value of the prototype under research consists in the real daily conditions under which it was tested. The first stage consisted of the site selection, and the manufacture of a waterproof iron reinforced cement prototype, with a 1m³ loading capacity. At this stage, during the period from august to december 2011, the reactor was inoculated with organic matter originating from the aforementioned restroom discharges. The evaluation of this stage consisted in taking measurements of the following field parameters: pH, electrical conductivity, sedimentable solids, and inflow and outflow temperature along the system. These records substantiated the behaviour of the processes within the digester during the starting phase. The results obtained through these determinations at both the biodigester entry and exit points are respectively: pH (8.03; 8.43), electrical conductivity (1510.83 µS/cm; 1207.00 µS/cm), inflow and outflow temperatures (19.2°C; 20.1°C), sedimentable solids (144.5mL/L; 0.02mL/L) and dissolved oxygen (4.5992 mg/L; 0.1924 g/L). These data provided a starting point for the treatment of domestic wastewater.

Association of Blood Group O with Gastrointestinal Bleeding in Continuous-Flow LVAD Patients.

Background: Increasing use of mechanical circulatory devices for advanced heart failure therapy has led to challenges in managing complications that arise from device implantation for long term support either as a bridge to transplant or as destination therapy. Patients with continuous flow left ventricular assist devices (CF-LVADS) show increasing incidence of gastrointestinal (GI) bleeds. Lack of pulsatality and narrow pulse pressure result in initiation and progression of arteriovenous malformations. High shear forces generated lead to destruction of von Willebrand factor (vWF) making it functionally inactive predisposing patients to increasing bleeding. Literature suggests that patients with blood type O have lower baseline levels of von Willebrand factor. It therefore seemed relevant to study the role of blood groups in this population. Methodology: Retrospective data analysis of 119 CF-LVADS patients discharged between 01/2005 and 07/2014. This study was approved by the Institutional Review Board on 08/01/2014. Results: Blood type (p=0.23), gender (p=0.16) and the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile (p=0.86) were not associated with significant incidence of GI bleeding. Blood group O was not associated with a higher incidence of GI bleeding (correlation coefficient =0.07) Patients supported on the HeartMate II (HMII) LVAD experienced more GI bleeding than patients supported on the HeartWare LVAD (HVAD) (p=0.009). HMII LVAD patients who experienced GI bleeding had a mean age of 59.8 years vs. 55.7 years for HMII LVAD patients in the Non-GI bleed group. Age was a significant factor for GI bleeding (p=0.016). Conclusion: Blood group and GI bleeding did not show any significant association in our study. Patients with blood group O did not show increased incidence of GI bleeding despite reported lower baseline levels of von Willebrand factor suggesting contribution of additional factors leading to this complication. The HVAD had a decreased incidence of GI bleeding as compared to Heartmate II. This study is limited by the fact that it was a retrospective analysis in a small population.

Reagent-free determination of amikacin content in amikacin sulfate injections by FTIR derivative spectroscopy in a continuous flow system / 药物分析学报

The quantitative estimation of amikacin (AMK) in AMK sulfate injection samples is reported using FTIR-derivative spectrometric method in a continuous flow system. Fourier transform of mid-IR spectra were recorded without any sample pretreatment. A good linear calibration (r40.999, %RSDo 2.0) in the range of 7.7-77.0 mg/mL was found. The results showed a good correlation with the manufacturer's and overall they all fell within acceptable limits of most pharmacopoeial monographs on AMK sulfate.

Anesthesia for gastrointestinal endoscopy in patients with left ventricular assist devices: Initial experience with 68 procedures.

Aims and Objectives: Continuous flow left ventricular assist devices (LVAD) have emerged as a reliable treatment option for heart failure. Because of bleeding secondary to anticoagulation, these patients present frequently for gastrointestinal (GI) endoscopy. The presently available literature on perioperative management of these patients is extremely limited and is primarily based upon theoretical principles. Materials and Methods: Perioperative records of patients with LVAD undergoing (GI) endoscopy between 2008 and 2012 were reviewed. Patient, device and procedure specific information was analyzed. Results: A total of 105 LVADs were implanted, and 68 procedures were performed in 39 patients. The most common indication was GI bleed (48/68), with yearly risk of 8.57% per patient. A total of 63 procedures were performed under deep sedation, with five procedures requiring general anesthesia. Intra‑procedure hypotension was managed by fluids and (or) vasopressors/inotropes (phenylephrine, ephedrine or milrinone) guided by plethysmographic waveform, non‑invasive blood pressure (NIBP) and LVADs pulsatility index (for HeartMate II)/flow pulsatility (for HeartWare). No patient required invasive monitoring and both NIBP and pulse oximeter could be reliably used for monitoring (and guided management) in all patients due to the presence of native heart’s pulsatile output. Conclusion: In the presence of residual heart function, with optimal device settings, non‑invasive hemodynamic monitoring can be reliably used in these patients while undergoing GI endoscopy under general anesthesia or monitored anesthesia care. Transient hypotensive episodes respond well to fluids/vasopressors without the need of increasing device speed that can be detrimental.

Comparação entre a Dopplermetria e o fluxo livre da artéria torácica interna de cães com e sem o uso de noradrenalina / Comparison between the Doppler flowmetry and the free flow of dog's internal thoracic artery with and without use norepinephrine

OBJETIVO: Este trabalho objetiva estudar comparativamente o fluxo livre e a dopplerfluxometria da artéria torácica interna de cães anestesiados com e sem a administração de noradrenalina endovenosa contínua. MÉTODOS: A amostra foi constituída de 10 cães mestiços, nos quais foram dissecadas as artérias torácicas internas direita e esquerda e avaliado seu fluxo; primeiramente, pela dopplerfluxometria e depois pelo fluxo livre. Foram registrados a pressão arterial média e o diâmetro das artérias no início do procedimento. As verificações do fluxo pelos dois métodos ocorreram em três tempos: tempo zero, 10 e 25 minutos. Após a primeira verificação no tempo zero, iniciou-se a infusão contínua de noradrenalina no átrio direito; as avaliações aos 10 e 25 minutos foram feitas da mesma forma que na primeira vez, nas mesmas artérias e pelos dois métodos, anotando-se os resultados, assim como a pressão arterial média correspondente. RESULTADOS: Os resultados da verificação de fluxo, entre Dopplermetria e fluxo livre, apresentaram-se similares; sendo os primeiros, nos tempos zero, 10 e 25 minutos, respectivamente, 183, 237 e 230,1 ml/min, comparados aos segundos, 168,6, 226,8 e 226,4 ml/min (P=0,285). A média das pressões arteriais dos três tempos e o diâmetro médio das artérias não apresentaram diferenças estatisticamente significativas entre os métodos, portanto, não influenciaram na comparação dos resultados. CONCLUSÃO: As avaliações, tanto da dopplerfluxometria quanto do fluxo livre, foram semelhantes nos três tempos verificados.

OBJECTIVE: This work aims to study comparatively the free flow and the Doppler flowmetry of the internal thoracic artery in anesthetized dogs, with and without continuous intravenous administration of norepinephrine. METHODS: The sample was made up of ten mongrel dogs, which dissected the left and right internal thoracic arteries and evaluated your stream; first, by Doppler flowmetry and then by free flow. The mean arterial pressure and the diameter of the arteries at the beginning of the procedure were registered. The workflow checks by two methods occurred in three times: time zero, 10 and 25 minutes. After the first check in time zero, the continuous infusion of norepinephrine in the right atrium; other checks were made in the same way that the first time, to 10 and 25 minutes, in the same arteries and by two methods, each one in his artery, noting the results, as well as the corresponding average blood pressure. RESULTS: The results of the scan of the stream, between Doppler flowmetry and free flow, there were similar; being the first, zero times, ten and twenty-five minutes, respectively, 183, 230.1 and 237 ml/min compared to seconds, 168.6, 226.8 and 226.4 ml/min (P = 0.285). The mean arterial pressures of three times and the average diameter of the arteries, showed no statistically significant differences between the methods, so did not influence on the comparison of the results. CONCLUSION: The evaluations, both from Doppler flowmetry and free flow, were similar in three times checked.

Viabilidade do tratamento de água residuária sintética têxtil em reator aeróbio de leito fixo / Viability of the synthetic textile wastewater treatment in a fixed-bed aerobic reactor

Um reator de escoamento contínuo, inoculado com Aspergillus niger AN400, possuía volume total de 5 L e foi operado a 29ºC, com oito horas de tempo de detenção hidráulica e 150 L.h-1 de vazão de ar, para remover 25 mg.L-1 de corante vermelho do congo de água residuária sintética. A alimentação do reator foi realizada em duas fases: Fase I, com 0,5 g.L-1 de sacarose e Fase II, sem sacarose. Na Fase I, foi possível observar eficiências de remoção de matéria orgânica (mg de DQO.L-1) e de cor (mg PT.L-1) de 80 ± 16 por cento e 82 ± 10 por cento (mg Pt.L-1), respectivamente. Na Fase II, a eficiência de remoção de matéria orgânica foi de 75 ± 13 por cento e de cor (mg Pt.L-1) de 89 ± 7 por cento. As maiores remoções de nutrientes foram alcançadas pelo reator na Fase I, com 25 por cento de amônia, 90 por cento de nitrito, 93 por cento de nitrato e 21 por cento de fósforo. Aparentemente, a presença de sacarose melhorou a remoção dos nutrientes.

A continuous flow reactor, inoculated with Aspergillus niger AN400, with total volume of 5 L was operated at 29oC, with eight hours of retention hydraulic time and 150 L.h-1 of air flow rate in order to remove 25 mg.L-1 of Congo Red dye from a synthetic wastewater. The feeding of the reactor, inoculated with Aspergillus niger AN400, was done in two phases: Phase I, with 0,5 g/L of saccharose and Phase II, with no saccharose. In Phase I, it was possible to verify efficiencies of organic matter and color (mg Pt.L-1) removal of 80 ± 16 percent and 82 ± 10 percent, respectively. In Phase II, the efficiency of organic matter removal was 75 ± 13 percent and color removal was 89 ± 7 percent. The higher removals of nutrients were achieved by the reactor in Phase I with 25 percent to ammonia, 90 percent to nitrite, 93 percent to nitrate and 21 percent to phosphorus. Apparently, the presence of saccharose improved the removal of the nutrients.

Continuous flow apneic ventilation with nitrous oxide-oxygen or oxygen in dogs / 中华麻醉学杂志

To investigate the difference of CO_2 transport during continuous flow apneic ventilation (CFAV) between with 100% 0_2 and with 60%N_2O-40% O_2. Method: Twelve dogs were randomly divided into equally group N_2O and group O_2. A catheter was introduced into each main-stem bronchus using a fiberoptic bronchoscope and endotraeheal tube positioned in place for CFAV. With 60%N_2O-40% O_2 in group N_2O and 100% O_2 in group O_2 lungs were ventilated at flow rate of 1L?kg~(-1)?min~(-1) Blood gas analysis, HR, MAP and SaO_2 were recorded every 30min during period of 180min. Result: In group O_2, PaCO_2 increased from 4.88?0.63kPa to 8.73?1.11kPa. In Group N_2O, PaCO_2 were increased gradually from 5.51?0.94kPa to 6.18?0.67kPa. There was significant difference in PaCO_2 between the two groups (P

Determination of Urea in Swimming Pool Water by Continuous Flow Injection Analysis / 环境与健康杂志

Objective To develop a stable and quick method to determine the urea in swimming pool water.Methods On the conditions of strong acid and calefaction,urea can react on antipyrine and diacetyl monoxime and become yellow which can be determined by colorimetric analysis in 450 nm with the ALLIANCE FUTURA continuous flow injection auto analysis system.Results Determined by this method,the linear range was 0.5-4.0 mg/L,the regression equation was y=0.077 5x+0.021 9,the correlative coefficient r=0.999,the detection limit was 0.07 mg/L.With residual chlorine of 0.3 and 3.0 mg/L,the recovery rates were 98.8%-104.0% and did not disturb the determination.The results determined by the present method were the same as those by the method in GB/T 18204.29-2000(Wilcoxon Signed Ranks Test:Z=0.051,P=0.959).Conclusion Determination of the urea in swimming pool water with continuous flow injection auto analysis,the sensitivity,accuracy and limit of determination can meet to the requirement,moreover,the analysis speed is faster,less reagent will be needed,the present method can be generalized in the laboratory that has the conditions.

Determination of Total Hardness in Water by Air-Segmented Continuous Flow Analysis / 环境与健康杂志

0.999 0, and RSDs were not more than 3.26%. The recovery rates were 94.12%-104.30% .The lowest detected concentration was 1.43 mg/L. There was no significant difference between the results of this method and Na2EDTA titration. Conclusion The method was rapid, accurate and highly sensitive.

Determination of Cyanide in Drinking Water by Continuous Flow-Injection-Photometry / 环境与健康杂志

Objective To establish a simple,accurate and sensitive method for determination of cyanide in drinking water. Methods By means of using flow injection analysis instrument, the cyanide in drinking water was determined on-line. Results The data obtained by this assay accorded with Beer's Law, the range was 2.0-50.0 ?g/L, r≥0.999, the detection limit, relative standard deviation and recovery rate were 0.23 ?g/L, 2.5%-3.8% and 94.9%-98.7% respectively. The sampling frequency was 20 samples per hour. Conclusion The method for determination of cyanide in drinking water employed in the present paper is simple, accurate, sensitive and suitable for the analysis of large number of water samples.

Determination of Potassium in Environmental Water Samples by Continuous Flow Analysis / 环境与健康杂志

Objective To establish a continuous flow analytical method for determination of potassium in environmental water sample.Methods The concentration of patassium in environmental water sample was determined by ALLIANCE auto-matic analyzer,and its data were compared with the data obtained from atomic absorption spectrophotometry.Results The de-tection limit of this method was0.5?g /ml.The method revealed linear relationship at the potassium concentrations of5-1000?g /ml.The recovery rate of standard addition method ranged from to97%to102%.The relative standard deviations were0.82%-1.23%.Conclusion The contents of potassium in environmental water samples could be accurately and rapidly deter-mined by continuous flow analysis.