Evaluation of antioxidant activity, phenolic content, anthocyanins, and flavonoids of fresh and dried 'Biloxi' blueberries / Evaluación de la actividad antioxidante, contenido fenólico, antocianinas y flavonoides de arándanos 'Biloxi' frescos y secos

BACKGROUND: The phytochemical content present in blueberries has generated great interest, especially in the nutra-pharmaceutical industry, where it is known as the "super fruit" due to its prevention and treatment of neurodegenerative diseases (cardiovascular diseases, diabetes, and cancer, among others). OBJECTIVES: This study evaluated the functional potential of fresh blueberries and dried blueberries using forced convection by measuring phytochemical content to conclude if this drying technology is convenient for prolonging the product's shelf life. METHODS: For this purpose, antioxidant activity, phenolic content, total anthocyanins, and total flavonoids of 'Biloxi' blueberry cultivars were determined. Fresh and dried blueberries' results were studied. Fruit extracts were analyzed to determine antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) as a free radical, total phenolic content with Folin-Ciocalteu reagent, total anthocyanins by pH differential method, and total flavonoids by Aluminum Chloride method. RESULTS: Results for fresh blueberries yielded ranges of antioxidant activity (90.8-93.9% Free radical scavenging rate), total phenolic content (275 to 645mgGAE/100gFW), total anthocyanins content (28.55 to 43.75mgCy3G/100gFW) and total flavonoids content (159.92 to 335.75mgQE/100gFW). For the forced convection oven process, ranges of antioxidant activity (85.5-92.6% Free radical scavenging rate), total phenolic content (261 to 308mgGAE/100gFW), total anthocyanins content (4.74 to 5.12mgCy3G/100gFW) and total flavonoids content (30.66±0.38mgQE/100gFW) were obtained. CONCLUSIONS: In general, blueberries studied proved to have similar concentrations of functional properties compared to a wide variety of cultivars grown around the globe. Furthermore, higher concentrations of phytochemical content than those reported previously for strawberries, blackberries, and raspberries were evidenced. Although dried blueberries studied proved to have diminished phytochemical content, this functional component content stands out among the fruits market and give nutritional value to end consumers. Drying processes could potentially increase the commerce of blueberries by significantly reducing their perishable nature

CONTEXTO: El contenido fitoquímico presente en los arándanos ha generado gran interés, especialmente en la industria nutra-farmacéutica donde es conocido como una "super fruta" debido a su ayuda en la prevención y tratamiento de enfermedades neurodegenerativas, enfermedades cardiovasculares, diabetes, cáncer, entre otras. OBJETIVOS: Este estudio evaluó el potencial funcional de arándanos frescos y deshidratados por convección forzada mediante la determinación de su contenido fitoquímico con el objetivo de concluir si esta tecnología de secado es conveniente para aumentar la vida útil del producto. MÉTODOS: Para este propósito, se determinó la actividad antioxidante, el contenido fenólico, las antocianinas totales y los flavonoides totales de cultivos de arándanos 'Biloxi' La información recopilada de la literatura fue analizada. Se estudió el contenido en compuestos funcionales en arándanos frescos y deshidratados. Los extractos de fruta fueron analizados para determinar actividad antioxidante por medio de 2,2-Difenil-1-Picrilhidrazilo (DPPH) como radical libre, fenólicos totales con el reactivo Folin-Ciocalteu, antocianinas totales usando el método diferencial de pH y flavonoides totales con el método de Cloruro de Aluminio. RESULTADOS: Para los arándanos frescos se obtuvieron rangos de actividad antioxidante de 90.8-93.9% Tasa de captación de radicales libres, contenido fenólico total de 275-645mgEAG/100gPF, contenido de antocianinas totales de 28.55-43.75mgCy3G/100gPF y contenido total de flavonoides de 159.92-335.75mgEQ/100gPF. Para los arándanos deshidratados por convección forzada, se obtuvieron rangos de actividad antioxidante de 85.5-92.6% Tasa de captación de radicales libres, contenido fenólico total de 261-308mgEAG/100gPF, contenido de antocianinas totales de 4.74-5.12mgCy3G/100gPF y contenido total de flavonoides de 30.24-30.96mgEQ/100gPF. CONCLUSIONES: En general, los arándanos estudiados probaron tener concentraciones similares de propiedades funcionales comparados con una amplia variedad de cultivos alrededor del mundo. Además, fueron evidenciadas concentraciones más altas de contenido fitoquímico comparadas con las reportadas previamente para fresas, moras y frambuesas. Aunque los arándanos secos estudiados demostraron tener menor contenido fitoquímico, la cantidad de estos componentes funcionales destaca dentro del mercado de las frutas y dan valor nutricional a los consumidores. Los procesos de secado pueden potencialmente incrementar el comercio de arándanos derivado de una disminución significativa en su naturaleza perecedera

Assessment of Heat and Mass Transfers by the Evaporation of a Large Impoundment under Dry and Hot Climate: Case of Burkina Faso

This paper aims to report a numerical study of the assessment of heat and mass transfers by evaporation of a large impoundment under Burkina Faso climate conditions. This impoundment is considered as a parallelepiped which upper face, in contact with the ambient environment and subject to solar radiation, is the seat of a natural convection-based evaporation. The intensity of this evaporation is modeled by a correlation in the literature. Transfers into water are made by natural convection. They are caused by temperature differences due to solar radiation and ambient conditions (wind, hygrometry of the air,) on water. These transfers are described by the Navier-Stokes equations and energy and the initial and boundary conditions associated with them. The finite volume method and the SIMPLE algorithm were used for speed-pressure coupling. The systems of algebraic equations deduced from the discretization of transfer equations and boundary conditions associated with them are solved with Thomas’ algorithm, the SIMPLE algorithm and an iterative procedure because evaporated water quantity depends on the temperature and concentration of water vapor at the surface of the impoundment which are the unknowns of the problem. The numerical model developed is validated in relation to previous work and experimental data from Burkina Faso meteorology. The results obtained concern the evolution of the evaporated water flux under dense solar flows, a relative humidity of the air proportional to the wind speed and also the evolution of the evaporated water flux against the solar flux density for high relative moisture content. Also the evolution of the evaporated water flow against the depth of the impoundment for a solar flux density, relative humidity and the temperature of the surface of the body of water is given. The determination of evaporated water flux for typical years was calculated on a 10-year period. The results obtained show that the flux of evaporated water increases with a high solar flux rate and decreases for a high relative humidity level.

Convection combined microwave drying affect quality of volatile oil compositions and quantity of curcuminoids of turmeric raw material

Abstract The aim of the work was to estimate the quality of some compositions in turmeric volatile oil and quantity of individual and total curcuminoids in turmeric powder dried under different conditions. Effect of convection time (0-30 min) and microwave time (20-60 min) on quality of volatile oil compositions and quantity of curcuminoids were investigated using computer software. Quality of volatile oil obtained from the hydrodistillation of dried turmeric was analyzed by gas chromatography-mass spectrometry. The quantity of individual curcuminoids (bisdemethoxycurcumin, demethoxycurcumin, and curcumin) and total curcuminoids were analyzed by high performance liquid chromatography. Ten volatile compounds in turmeric volatile oil were used to estimate the variation of their quality. Results showed that ar-turmerone, turmerone, and curlone were the three major compounds found in turmeric volatile oil. The quality of the ten volatile compounds varied depending on convection time and microwave time. The three principal curcuminoids were found in turmeric dried at long convection time and medium microwave time. However, curcumin was also found in high amount in turmeric dried at short convection time and long microwave time. Total curcuminoids in dried turmeric were equal to or greater than 5% (w/w) as stated in the Thai Herbal Pharmacopoeia. It was found that almost all of the drying procedure achieved the standard of the Thai Herbal Pharmacopoeia except at short convection time and short microwave time. In summary, convection combined with microwave drying affected the quality of volatile oil compositions and quantity of curcuminoids of turmeric raw material.

Plumas em escoamento uniforme com estratificação de duas camadas / Plumes in uniform flow with two-layer stratification

RESUMO Plumas ocorrem quando um fluido é descarregado em outro fluido com densidade diferente, como poluentes na atmosfera. Neste trabalho, desenvolveu-se um estudo experimental em um tanque de água e modelagem matemática usando a abordagem integral com o intuito de investigar o escoamento gerado por plumas salinas em escoamento uniforme e com estratificação de duas camadas. Os resultados indicaram que a altura da camada superior (menos densa) aumentou com a vazão de retirada da camada inferior e diminuiu com o fluxo de empuxo da pluma, corroborando os resultados disponíveis na literatura para sistemas alimentados por fontes pontuais (não uniformes). Após ajuste de parâmetros presentes na teoria clássica para plumas turbulentas, foi possível prever a altura da interface com desvios máximos de ±8% e coeficiente de Nash-Sutcliffe de 0,98. Isso indica que o escoamento uniforme não afetou significativamente a hidrodinâmica das plumas em comparação a estudos anteriores. Por outro lado, diferentemente dos sistemas alimentados por fontes pontuais, as linhas de fluxo obtidas por meio da injeção de corante no escoamento uniforme seguiram padrão de escoamento potencial, com toda a vazão sendo direcionada para a pluma e não havendo, portanto, mistura na interface entre as duas camadas. Dessa forma, partindo do princípio de conservação de massa, foram propostas equações para gerar as linhas de fluxo ao redor das plumas, as quais foram confirmadas com os dados experimentais. Finalmente, foram apresentadas aplicações práticas do modelo proposto em sistemas de ventilação natural em edifícios e descarga de poluentes na atmosfera sob condição de inversão térmica.

ABSTRACT Plumes occur when a fluid is discharged into another fluid with different density, such as pollutants in the atmosphere. In this work, an experimental study was carried out in a water tank and a mathematical modelling using the integral approach was performed to investigate the flow generated by saline plumes in uniform flow with two-layer stratification. The results indicated that the upper layer's height (less dense) increased with the outflow from the lower layer, and decreased with the buoyancy flux of the plume, confirming the results available in the literature for systems supplied by point sources (non-uniform sources). After fitting the parameters of the classical theory for turbulent plumes, it was possible to predict the interface's height with a maximum deviation of ±8%, and a Nash-Sutcliffe coefficient of 0.98. This indicates that the uniform flow did not affect significantly the plumes' hydrodynamics compared to previous studies. On the other hand, unlike the systems supplied by point sources, the streamlines obtained through the injection of dye into the uniform flow followed a potential flow pattern, with all the flow being directed to the plume, therefore not mixing at the interface between the two layers. Thus, based on the principle of mass conservation, equations were proposed to generate the streamlines around the plumes, which were validated with the experimental data. Finally, practical applications of the proposed model in natural ventilation in buildings and pollutant discharges in the atmosphere were presented.

Optimization of ultra-fast convection polymerase chain reaction conditions for pathogen detection with nucleic acid lateral flow immunoassay

Recently, the importance of on-site detection of pathogens has drawn attention in the field of molecular diagnostics. Unlike in a laboratory environment, on-site detection of pathogens is performed under limited resources. In this study, we tried to optimize the experimental conditions for on-site detection of pathogens using a combination of ultra-fast convection polymerase chain reaction (cPCR), which does not require regular electricity, and nucleic acid lateral flow (NALF) immunoassay. Salmonella species was used as the model pathogen. DNA was amplified within 21 minutes (equivalent to 30 cycles of polymerase chain reaction) using ultra-fast cPCR, and the amplified DNA was detected within approximately 5 minutes using NALF immunoassay with nucleic acid detection (NAD) cassettes. In order to avoid false-positive results with NAD cassettes, we reduced the primer concentration or ultra-fast cPCR run time. For singleplex ultra-fast cPCR, the primer concentration needed to be lowered to 3 µM or the run time needed to be reduced to 14 minutes. For duplex ultra-fast cPCR, 2 µM of each primer set needed to be used or the run time needed to be reduced to 14 minutes. Under the conditions optimized in this study, the combination of ultra-fast cPCR and NALF immunoassay can be applied to on-site detection of pathogens. The combination can be easily applied to the detection of oral pathogens.

Study on Mathematical Model and Simulation of Competition-type Lateral Flow Immunoassay / 分析化学

A mathematical model of competition-type lateral flow immunoassay (LFIA) was developed to describe the dynamic process of LFIA.The competition-type LFIA was divided into two categories: TwA-competition-type LFIA and TnA-competition-type LFIA.On the basis of the developed model, the COMSOL software was exploited to simulate the dynamic process of LFIA.The simulation result demonstrated the relationships between the concentrations of substances on the test and control lines and the influence factors.In particular, the influence factors in the TwA-competition-type LFIA included the concentrations of target analyte A (0-20 mol/L) and reporter particle P (0.01-100 mol/L), and the position of the test line (5-20 mm).On the other hand, the influence factors in the TnA-competition-type LFIA included the concentrations of target analyte A (0-20 mol/L) and reporter particle P (0.01-100 mol/L), and the porosity.Experiment result showed that the developed model could be used to explore the influence of the parameters on the test results, and optimize the performance of LFIA.

Soft Collagen-Gelatine Sponges by Convection Drying

This study showed that thermally labile fibrillar collagen could be processed continuously in combination with gelatine as foaming additive by convection drying. The procedure led to stable sponges with similar structural and physical properties as found for freeze-dried collagen samples. The fibrillar collagen remained native, while gelatine acted as foaming additive. The absorbency of the sponges was improved by opening the surface with abrasives. A use as medical device with hemostyptic properties would be possible.

PARAMETRIC ANALYSIS OF DRUG DISTRIBUTION DURING INFUSIONS INTO THE BRAIN USING AN AXISYMMETRIC MODEL WITH BACKFLOW / ANÁLISIS PARAMÉTRICO DE LA DISTRIBUCIÓN DE DROGA DURANTE INFUSIONES EN EL CEREBRO CON UN MODELO AXISIMÉTRICO CON REFLUJO / A ANÁLISE PARAMÉTRICA DE DISTRIBUIÇÃO DE DROGAS NO CÉREBRO DURANTE INFUSÕES COM UM MODELO AXISYMMETRIC COM REFLUXO

Convection-enhanced delivery as a means to deliver therapeutic drugs directly to the brain has shown limited clinical efficacy, primarily attributed to the phenomena of backflow, in which the infused fluid flows preferentially along the shaft catheter rather than forward into the tissue. We have previously developed a finite element model of backflow that includes both material and geometric nonlinearities and the free boundary conditions associated with the displacement of the tissue away from the external surface of the catheter. However, that study was limited to predictions of the tissue deformation and resulting convective fluid velocity in the interstitial space. In this study, we use results from that model to solve for the distribution of the infused therapeutic agent. We demonstrate that a significant percentage of the infused drug is not transported into the region of tissue located forward from the catheter tip, but instead is transported into the region along the lateral sides of the catheter. For lower flow rates, this study suggests that the use of a catheter with a larger radius may be preferable since it will provide the higher amount of drug to be transported to the tissue in front of the catheter. In contrast, for higher flow rates consistent with clinical infusions, the radius of the infusion catheter had minimal effect on the distribution of the infused drug, with most being transported into the tissue around the shaft of the catheter.

Convection-enhanced delivery es una técnica que permite transportar drogas directamente en el cerebro para el tratamiento de enfermedades del sistema nervioso central. Este método ha mostrado una eficacia limitada debido principalmente al fenómeno de reflujo (backflow), según el cual, el fluido inyectado fluye preferiblemente a lo largo del catéter y no hacia el tejido delante de la punta. Previamente desarrollamos un modelo de elementos finitos para representar el reflujo, el cual incluye las no linealidades geométricas y del material y las condiciones de borde libre asociadas con el desplazamiento del tejido en la superficie externa del catéter. Sin embargo, ese modelo solo predice la deformación del tejido y el campo de velocidades en el espacio intersticial. En este estudio, hemos utilizado los resultados provenientes del mencionado modelo bifásico para resolver la ecuación de transporte de masa y predecir la distribución de droga suministrada. Se pudo demostrar que un porcentaje significativo de droga no penetra en el tejido ubicado delante de la punta del catéter, sino que es transportado hacia el tejido ubicado alrededor del catéter. Para bajo caudales, este estudio sugiere que el uso de un catéter con un radio mayor permitiría transportar una mayor cantidad de droga hacia el tejido al frente de la punta. Por otro lado, para los mayores caudales usados en la práctica clínica, el radio del catéter tiene un efecto marginal en la distribución del fármaco, y la mayor cantidad de droga se transporta hacia el tejido ubicado alrededor del catéter.

Convection-enhanced delivery é uma técnica para o transporte de drogas directamente no cérebro para tratar doenças do sistema nervoso central. Este método tem demonstrado eficácia limitada devido, principalmente, ao fenómeno de refluxo (refluxo), através do qual, de preferência, o fluido injectado flui através do cateter para o tecido e não à frente da ponta. Anteriormente desenvolvido um modelo de elementos finitos para representar a refluxo, que inclui geométricas e não-linearidades do material e as condições associadas com a extremidade livre de deslocamento da trama na superfície exterior do cateter. No entanto, este modelo apenas prevê deformação do tecido e campo de velocidades no espaço intersticial. Neste estudo, foram utilizados os resultados do modelo de duas fases acima referidas, para resolver a equação de transporte e prever a distribuição de massa de medicamentos fornecidos. Demonstrou-se que uma percentagem significativa da droga não penetra no tecido localizado em frente da ponta do cateter, que é transportado para o tecido que rodeia o cateter. Para as taxas de fluxo baixas, este estudo sugere que o uso de um cateter com um raio maior do que transportar uma maior quantidade de droga para o tecido em frente da ponta. Além disso, para taxas de fluxo mais elevadas utilizadas na prática clínica, o raio do cateter tem um efeito marginal sobre a distribuição da droga, e tanto fármaco é transportado para o tecido que rodeia o cateter.

Estudo da variabilidade da cobertura de nuvens altas na Amazônia Central / Study of the variability of high cloud covering over Central Amazon region

Foram estudados os fenômenos meteorológicos que ocorrem na Amazônia Central (Manaus) utilizando-se um conjunto de imagens de satélites, com o objetivo de identificar as oscilações que mais contribuem para a variabilidade da cobertura de nuvens, e verificar se há modificações nestas oscilações em anos de El Niño e La Niña. O ciclo anual e o ciclo semi-anual são os principais responsáveis pela variabilidade da cobertura de nuvens altas na região. As oscilações interanuais associadas aos fenômenos El Niño/La Niña também contribuem fortemente para a variabilidade total da cobertura de nuvens altas. As oscilações intra-sazonais e interdiurnas apresentam uma variabilidade menor. Estendendo-se a análise para uma região compreendida de 1,5°S a 6°S e 68°W a 54°W, centrados em Manaus, observa-se que os períodos de 60, 45 e 30 dias possuem maior porcentagem de potência a leste de Manaus; o período de 20 dias possui maior porcentagem de potência no centro (próximo de Manaus); e os períodos de 8, 6 e 4 dias possuem maior porcentagem de potência a oeste de Manaus. As frentes frias que alcançam a janela de 10° de longitude e 2,5° de latitude centrada em Manaus, modulam de alguma forma a atividade convectiva na região de Manaus atuando como uma forçante das oscilações interdiurnas (47 por cento dos casos), das oscilações intra-sazonais, (15 por cento) e das oscilações de 55 a 65 dias (13 por cento). Convém ressaltar que não necessariamente as frentes frias causaram as oscilações. As frentes podem favorecer ou induzir a convecção no local.

The meteorological phenomena that occur in the Central Amazonia (Manaus) are studied from ISCCP-C1 Satellite- based data. The oscillations that contribute more significantly to the cloud cover variability and its relation to El Niño and La Niña events case identified. The annual and semi-annual oscillation times scales are the main responsible for the variability of the high cloud cover over Manaus. The inter-annual oscillations associated with El Niño and La Niña events also contribute significantly to the total variability of the high cloud cover, while intraseasonal and day-to-day oscillations show a reduced contribution. However, the intraseasonal and day-to-day oscillations are important since they do influence the predictability on short and medium range forecast. The studied region was extended to 21 sections, centered in Manaus. The 60, 45 and 30 day-oscillations exhibited a higher spectral power density percentage over eastern Manaus; the 20 day-oscillations, over the central Manaus; and the 8, 6 and 4 day-oscillations, over western Manaus. The cold fronts that reach central Amazonia modulate convective activity over Manaus region, acting as a forcing for day-to-day oscillations (47 percent of the cases), intraseasonal oscillations (15 percent), and 55 to 65 day- oscillations (13 percent). It is important to point out that the cold fronts did not necessarily establish the oscillations, but they may have favored or induced convection over Manaus region.

Diurnal variability of rainfall in southwest Amazonia during the LBA-TRMM field campaign of the austral summer of 1999 / Variação diurna da chuva no sudoeste da Amazônia durante a campanha de campo do experimento LBA-TRMM no verão austral de 1999

The TRMM-LBA field campaign was held during the austral summer of 1999 in southwestern Amazonia. Among the major objectives, was the identification and description of the diurnal variability of rainfall in the region, associated with the different rain producing weather systems that occurred during the January-February season. By using a network of 40 digital rain gauges implemented in the state of Rondônia, and together with observations and analyses of circulation and convection, it was possible to identify details of the diurnal cycle of rainfall and the associated rainfall mechanisms. Rainfall episodes were characterized by regimes of "low-level easterly" and "westerly" winds in the context of the large-scale circulation. The westerly regime is related to an enhanced South Atlantic Convergence Zone (SACZ) and an intense and/or wide Low Level Jet (LLJ) east of the Andes, which can extend eastward towards Rondônia, even though some westerly regime episodes also show a LLJ that remains close to the foothill of the Andes. The easterly regime is related to easterly propagating systems (e.g. squall-lines) with possible weakened or less frequent LLJs and a suppressed SACZ. Diurnal variability of rainfall during westerly surface wind regime shows a characteristic maximum at late afternoon followed by a relatively weaker second maximum at early evening (2100 Local Standard Time LST). The easterly regime composite shows an early morning maximum followed by an even stronger maximum in the afternoon.

O experimento de campo do TRMM-LBA ocorreu conteceu durante o verão austral de 1999, na região do sudeste de Amazonia. Entre os principais objetivos deste trabalho pode-se citar a identificação e descrição da variabilidade diurna da chuva nesta região, associada a diferentes fenômenos meteorológicos e sistemas de tempo que ocorreram durante o período de Janeiro-Fevereiro. Usando uma rede de 40 pluviômetros instalados no estado de Rondônia, ,juntamente com outras observações de circulação atmosférica e convecção, foi possível identificar detalhes do ciclo diurno de chuva e os mecanismos de circulação associados. Os eventos de chuva foram caracterizados por regimes de vento nos níveis baixos e no contexto da circulação de grande escala: ventos de oeste e de leste. O regime "de oeste" se associa a Zona de Convergência do Atlântico Sul (ZCAS) e a episódios intensos de jatos de baixos níveis ao leste dos Andes (LLJ), que podem estender seus efeitos até Rondônia. Episódios de eventos "de leste" se associam a sistemas meteorológicos que se propagam desde a Foz do Rio Amazonas em direção oeste (e.g. linhas de instabilidade) e podem ser acompanhados por episódios fracos de LLJ e de ZCAS. A variabilidade diurna de chuva durante episódios de circulação "de oeste" apresenta um máximo característico á tarde (1200-1400 hora local) com um máximo secundário á noite (2000-2200 hora local). O regime de circulação "de leste" mostra um máximo á tarde (1200-1400 hora local), precedido de um máximo secundário durante a madrugada (0000-0200 hora local).

Continuous Intratumoral Delivery of Chemotherapeutic Agent by Convection-enhanced Technique: Preliminary Clinical Study

OBJECTIVE: Because of the limited penetration into the central nervous system after systemic administration of numerous therapeutic compounds, intratumoral chemotherapy for brain tumors has also been used. However, the efficacy of intratumoral drug administration is restricted by the poor diffusion of drug through tumor and brain interstitium. In order to enhance the diffusion of chemotherapeutic agent and increase the cytotoxicity with minimal dose, the authors report the results of convection-enhanced delivery(CED) of chemotherapeutic agent to the malignant brain tumor as a method of enhancing cerebral drug delivery. METHODS: Authors used "CADD-Micro(R) ambulatory infusion pump" from Deltec, which can be programmed for continuous infusion. Intratumoral injection of chemotherapeutic drug using the pump was applied to eight patients with glioma and one patient with lymphoma. Surgery was done and tumor was removed as much as possible. The tip of catheter was placed in the center of tumor cavity. Adriamycin (0.16~0.32mg) was put in the reservoir which was connected to the proximal catheter and fixed in the pump device. Twenty-four hours after surgery, Adriamycin was infused. RESULTS: There was no adverse reaction of CED technique. Compared with current delivery techniques, the improvement of survival rate has been observed(5 patients: alive, 3 patients: dead, 1 patient: lost(alive to 5 mo.)). CONCLUSION: CED can be useful method for distributing therapeutic molecules in the interstitial space of tumor and can be utilized for chemotherapeutic agents, immunotoxins, and gene etc..

Head Position Dependency of Induced Nystagmus to Ice Water Irrigation in peripheral vestibulopathy

BACKGROUNDS AND OBJECTIVES: The direction of caloric nystagmus depends on the head position as long as vestibular function is remaining but the it does not depend on head position change in the lateral semicircular canal (SCC) plugged ear, which is attributed to thermoconvection in the lateral SCC. So determination of head position dependency using ice water test is recommended in the evaluation of peripheral vestibulopathy in which dead labyrinth is suspected. Since ice water test in prone position is frequently skipped and neglected in many vestibular laboratories, we investigated the importance and necessity of evaluating head position dependency for the candidates of ice water test and estimated the amount of head position non-dependent component in discussion. MATERIALS AND METHOD: From January through September 2003, 25 patients, who showed no nystagmus during warm irrigation, were included in this study. Following forty milliliter of ice water irrigation in supine & prone position, the maximum slow phase eye velocity (SPEV) and direction of nystagmus were assessed using video nystagmography system. RESULT: Eleven cases showed head-position dependency and were interpreted as hypofunction of lateral SCC. Fourteen cases did not show head position dependency suggesting the absence of end organ function. However, in the latter group, 6 patients, who showed definite nystagmus to ice water irrigation in supine position, can be midinterpreted as hypofunction if ice water test in prone position is not performed. CONCLUSION: Evaluation of head position dependency in ice water irrigation is an important procedure in the determination of lateral SCC function and can provide valuable information when vestibular ablative procedures are considered.

A Study of Non-Convective Factor of Caloric Nystagmus in Relationship between Head Position and Maximal Slow Phase Eye Velocity / 대한이비인후과학회지

Background and OBJECTIVE: There are strong evidences that the caloric nystagmus may be due to non-convective factors in addition to the widely accepted Barany's convection theory. The influence of non-convective factor on the caloric nystagmus was interpreted by measuring the maximal slow phase eye velocity according to the head position. MATERIALS AND METHODS: In 18 normal ears, the maximal slow phase eye velocity of the cold caloric nystagmus was measured at five (-15degrees, 05degrees, 305degrees, 455degrees, 605degrees) different head positions. RESULTS: The sine value of the angle of the lateral semicircular canal (LSCC) plotted against the maximal slow phase velocity showed linear relationship without crossing the zero point in linear regression analysis. CONCLUSION: Maximal slow phase eye velocity shows linear relationship with the sine value of the angle of the LSCC. Compared with the curve expected by the convective factor, the curve in this study was biased by a constant amount (about 20%), which can be attributed to non-convective factor.

Significance of Caloric Test in Reversed Position / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Caloric nystagmus has been known since a century ago, and the thermal convection theory proposed by Barany has been widely accepted. Gravity plays an important role in thermal convection. In 1984, caloric nystagmus was reported in weightless space environments and although the response was weak, the nystagmus was found to occur in the same direction as the earth. This implies that factors other than thermal convection might participate in the caloric nystagmus. MATERIALS AND METHODS: Using 50 normal ears as subjects, this study compared the responses of conventional caloric test and reversed caloric test, which places the plane of the lateral semicircular canal upside down. RESULTS: The direction of the nystagmus was reversed, and the maximal slow phase velocity was decreased compared to that of the normal caloric test. CONCLUSION: The reversed direction of the nystagmus observed in this study basically supports the theory by Barany, however, the differences that are noted implicate that other factors with a certain direction maybe involved.

The effect of environment temperature on thermal regulation during prolonged exercise. From the standpoint of individual variation / 体力科学

The purpose of this study was to investigate the possible individual difference in temperature regulating ability during identical relative exercise load under various temperature environments.<BR>Seven healthy males, aged 21 to 26 years, performed bicycle ergometer exercise of 60% VO<SUB>2</SUB>max for 60 minutes. All exercises were carried out in a climatic chamber under the conditions of 15°C (RH=70%), 25°C (RH=55%) or 35°C (RH=45%) . Herat rate, O<SUB>2</SUB> consumption, pulmonary ventilation, rectal temperature, mean skin temperature, local sweat rate at the lower part of scapula and total sweat rate were determined intermittently through the experiments. Moreover, heat loss by evaporation, radiation, convection and effective sweat rate was calculated using the heat valance equations.<BR>The results obtained are as follows :<BR>1. The increase in rectal temperature at the end of exercise was almost identical in 15°C and 25°C but significantly higher in 35°C.<BR>2. A significant positive correlation was observed between mean skin temperature (ΔTsk) at the end of exercise and effective sweat rate (r=0.468, p<0.05) during exercise.<BR>3. Inspite of the equality of relative exercise intensity (60%VO<SUB>2</SUB>max), marked individual variations were observed in rectal temperature during exercise.<BR>4. The subjects who showed marked increase in rectal temperature during exercise showed less marked increase in mean skin temperature in 15°C and 25°C and less marked increase in local sweat rate in 35°C than other subjects.<BR>It would be concluded that the main cause of individual variation in rectal temperature during exercise depends on difference in evaporative heat loss in hot environment and difference in skin temperature in mild or cold environment.