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

Effect of convection enhanced delivery on the microstructure of brain extracellular space in aged rats / 北京大学学报(医学版)

OBJECTIVE@#To compare the changes of extracellular space (ECS) structure and local drug distribution in adult brain and aged brain at different drug delivery rates in minimally invasive treatment of encephalopathy by convection enhanced delivery (CED) via ECS pathway.@*METHODS@#Thirty-six SD male rats were divided into adult rats group (2-8 months, n=18) and aged rats group (18-24 months, n=18) according to the age of the month. According to the drug rates (0.1 μL/min, 0.2 μL/min, and 0.3 μL/min), they were randomly divided into 3 subgroups, 6 in each subgroup. Gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) with a concentration of 10 mmol/L were introduced into the caudate nucleus of each group of rats by stereotactic injection. Tracer-based magnetic resonance imaging (MRI) was used to dynamically monitor the diffusion and distribution images of the Gd-DTPA in the brain interstitial system (ISS). Using the self-developed MRI image measurement and analysis system software to process and analyze the obtained images, the diffusion coefficient, clearance rate, volume fraction, and half-life of each group of rats in the caudate nucleus ECS could be acquired. The effects and differences of drug clearance and ECS structural function in the brain of aged rats and adult rats were compared and analyzed at different drug delivery rates. Magnetic tracer DECS-mapping technique was used to observe the distribution and drainage of tracer in caudate nucleus.@*RESULTS@#At the injection rate of 0.1 μL/min, the volume fraction in the aged rats was increased compared with that in the adult rats (18.20%±0.04% vs. 17.20%±0.03%, t=3.752, P=0.004), and the degree of tortuosity was decreased (1.63±0.04 vs. 1.78±0.09, t=-3.680, P=0.004), the drug clearance rate was decreased [(1.94±0.68) mm2/s vs. (3.25±0.43) mm2/s, t=-3.971, P=0.003], and the molecular diffusion in ECS was increased [(3.99±0.21)×10-4 mm2/s vs. (3.36±0.37)×10-4 mm2/s, t=3.663, P=0.004]. When the rate of injection increased to 0.2 μL/min, the drug clearance in ECS of the aged rats was slowed down [(2.53±0.45) mmol/L vs. (3.37±0.72) mmol/L, t=-1.828, P=0.021]. However, there were no significant differences in volume fraction, molecular diffusion in ECS and macroscopic drug metabolism parameters. When the rate of injection increased to 0.3 μL/min, the volume fraction in the aged rats was decreased (17.20%±0.03% vs. 18.20%±0.05%, t=-0.869, P=0.045), and the drug clearance rate in ECS was significantly accelerated [(4.04±0.76) mmol/L vs. (3.26±0.55) mmol/L, t=1.786, P=0.014], and there was no significant difference in tortuosity and the rate of molecular diffusion in the ECS.@*CONCLUSION@#The drug clearance and ECS structural parameters of brain ECS in aged brain with CED administration were changed at different rates, and it has the least effect on ECS in the aged brain at the injection rate of 0.2 μL/min. For the application of CED for the treatment of encephalopathy, we should consider the influence of factors such as age and injection rate, and provide reference for the development of individualized clinical treatment plan for minimally invasive treatment of encephalopathy via ECS pathway.

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.

Online hemodiafiltration and mortality risk in end-stage renal disease patients: A critical appraisal of current evidence

The life expectancy of end-stage renal disease patients undergoing regular hemodialysis (HD) remains significantly lower than in the general population. Reducing excess mortality by improving renal replacement options is an unmet medical need. Online post-dilution hemodiafiltration (HDF) has been promoted as the gold standard, offering improved clinical outcomes, based on numerous observational studies that suggest a reduced mortality risk and lower morbidity with HDF compared with standard HD. However, most randomized controlled trials (RCTs) have failed to demonstrate a significant beneficial effect of HDF on all-cause mortality. The effects on secondary outcomes were often negligible or absent. Unfortunately, these RCTs were characterized by a moderate to high risk of bias. In post-hoc analyses of the largest RCTs and meta-analysis of individual participant data from four RCTs, HDF patients receiving the highest convection volume consistently and dose-dependently saw superior outcomes. However, as these studies were not designed a priori to clarify this issue, and there are no indisputable mechanisms underlying reduced mortality risks, we cannot exclude the possibility that the health status of patients (with vascular access as a proxy) may affect outcomes more than the convective technique itself. There is currently insufficient evidence to support the contention that high-volume HDF confers relevant benefits to patients over standard HD. The conflicting data of published RCTs reduce confidence in the superiority of high-volume convective therapy. Hopefully, ongoing large RCTs (for example, CONVINCE) may supply an indisputable answer to the crucial question of high-volume HDF.

Evaluation on HACCP prerequisite-program performance within general hospital foodservice operations / 한국영양학회지

PURPOSE: This study was conducted to examine prerequisite-program performance of the hospital foodservice operation and develop measures for improvement of prerequisite-program performance. METHODS: Data were collected through surveys administered to 168 hospital dieticians in the Seoul, Incheon, Gyeonggi-do, Daegu, and North Gyeongsang areas. Out of total questionnaires, 65 questionnaires were usable and the response rate was 38.7%. Statistical analyses were performed using the SPSS program (ver 20.0) for chi2-test and one-way ANOVA. RESULTS: According to the result of the prerequisite-program evaluation, the percentage of 'appropriate', 'needs to be improved', and 'inappropriate' was 44.6%, 47.7%, and 7.7%, respectively. The score for the 'inappropriate' group was significantly lower than that of the 'appropriate' group or 'needs to be improved' group on the food safety management (p < 0.001), preparation facility management (p < 0.001), water management (p < 0.001), and storage.transportation management (p < 0.05) parts. Holding rate of foodservice facility and equipments in the 'appropriate' group were significantly higher than in the others on convection oven (p < 0.01), air conditioner (p < 0.01), three-compartment sink (p < 0.01), hot-holding equipment (p < 0.01), cold-holding equipment (p < 0.05), exclusive thawing refrigerator (p < 0.05), and sterilizer for sanitary shoes (p < 0.05) items. CONCLUSION: To improve the quality of hospital foodservice, foodservice managers and HACCP specialists should develop and implement a prerequisite-program and a HACCP plan considering the characteristics of the hospital foodservice operation.

Investigating the impacts of global environmental evolutions on long-term planning of natural resources in Iran

The main objective of the current study is to investigate the impacts of environmental evolutions at global scale on Iran's environmental planning. Thereby, all political movements towards solving environmental issues in Iran were accurately reviewed to find out the impressibility of the events by the global environmental evolutions. The findings indicated that Iran has joined the conventions and protocols with a time lag. During the period 1948-1993, the mean time lag between holding an international convention until its approval in Iran was eleven years while from 1994 to 2007, the average lag time was shortened to four years. As the results show, attention to environmental issues was improved from one note on First Development Plan of the country [1989-1993], to three notes on the Second Development Plan [1995-1999], and one complete chapter on the Third Development Plan [2000-2005]. Moreover, one of the six chapters of the Fourth Development Plan [2005-2009] [about 20 percent of the whole program] was dedicated to the environmental issues. In the Fifth Development Plan [2011-2015], sixteen topics have been raised at Environment Chapter and thirteen legal articles have been proposed in other chapters with a focus on environmental issues. It can be concluded that there has always been a direct link between international treaties and major political decisions in Iran

Investigation of Water Safety in Non-treated Drinking Water with Trace Toxic Metals

The trace toxic metal copper was assayed using mercury immobilized on a carbon nanotube electrode (MCW), with a graphite counter and a reference electrode. In this study, a macro-scale convection motor was interfaced with a MCW three-electrode system, in which a handmade MCW was optimized using cyclic-and square-wave stripping voltammetry. An analytical electrolyte for tap water was used instead of an expensive acid or base ionic solution. Under these conditions, optimum parameters were 0.09 V amplitude, 40 Hz frequency, 0.01 V incremental potential, and a 60-s accumulation time. A diagnostic working curve was obtained from 50.0 to 350 microg/L. At a constant Cu(II) concentration of 10.0 microg/L, the statistical relative standard deviation was 1.78% (RSD, n = 15), the analytical accumulation time was only 60 s, and the analytical detection limit approached 4.6 microg/L (signal/noise = 3). The results were applied to non-treated drinking water. The content of the analyzed copper using 9.0 and 4.0 microg/L standards were 8.68 microg/L and 3.96 microg/L; statistical values R2 = 0.9987 and R2 = 0.9534, respectively. This method is applicable to biological diagnostics or food surveys.

Analysis of Hospital Foodservice Management and Health Insurance Coverage of Inpatient Meals in Seoul

The objectives of this study were to explore hospital foodservice management and to investigate conditions related to health insurance coverage of inpatient meals. A questionnaire was distributed to the nutrition departments of 44 hospitals in Seoul on July 2009. The average kitchen area was 0.5 m2, and centralized distribution systems were in place. Partition walls from contamination zones, separate work tables to prevent cross-contamination, exclusive areas for preparing tube feeding, and split carts with refrigerated and convection heat settings were largely used in tertiary hospitals. Most dietitians did meal rounds (93.2%) and surveyed for patient satisfaction (86.4%). The major theme of QI (Quality Improvement) was menu management (31.8%). The health insurance fees for meals were 4,938.9 won for a general diet, 5,199.8 won for a therapeutic diet, 4,067.0 won for tube feeding, 9,950.0 won for sterilized diet, and 18,383.4 won for diets not covered by health insurance. The prices for general and therapeutic diets were significantly lower in hospitals compared to tertiary or general hospitals (P<0.001). The cost composed of 48.3% food, 44.0% labor and 7.7% overhead for general diets and 47.9%, 44.5% and 7.6% for therapeutic diets. In the case of health insurance coverage for patient meals, the number of items applied to general diets averaged 2.8 out of 4 and for therapeutic diets it averaged 1.9 out of 3. To reform the health insurance coverage system for patient meals, it is urgent that the qualified level of patient meals is presented from a national viewpoint, and monitoring should be performed consistently by developing the evaluation tools.

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.

The effectiveness of on-line hemodiafiltration on beta-2 microglobulin clearance in end stage renal disease.

OBJECTIVE: To compare beta2-microglobulin (beta2M) clearance between on-line hemodiafiltration (HDF) and high flux hemodialysis (HFHD). MATERIAL AND METHOD: The total, convection/diffusion, and membrane adsorption components of beta2M clearance in 10 hemodialysis patients treated with on-line HDF at the replacement fluid rates of 75 (HDF75) and 125 (HDF125) mL/min, were determined and compared with HFHD. RESULTS: The total beta2M clearance in the HDF 125 group was significantly higher than the HDF75 group (124.5 +/- 4.4 vs 101.3 +/- 4.1 mL/min; p < 0.05); both values were much greater than the HFHD group (p < 0.01). The convection/diffusion was the major portion of total beta2M clearance in all three groups. The values of convection/diffusion and membrane adsorption in both HDF groups were about 2 and 3 times, respectively, of the HFHD group (p < 0.01). Both components of beta2M clearance in the HDF125 group did not statistically differ from the HDF75 group, however; the value of convection/diffusion clearance in HDF125 was more than in the HDF75 group. Regarding Kt/Vurea and phosphate clearance, there were no significant differences among the study groups. CONCLUSION: On-line HDF could provide more beta2M clearance than HFHD by increasing both the convection/ diffusion, and membrane adsorption clearances. HDF125 provided more total beta2M clearance than HDF75 from the convection/diffusion mechanism while the adsorptive mechanisms were equal.

Convección de calor en el flujo de fluidos viscosos a través de un lecho de empaque metálico / Convective heat transfer for viscous fluid flow through a metalic

Se presenta un metodología teórico-experimental para determinar los coeficientes de convección intersticial de calor promedio en el flujo de aceite a través de un lecho de empaque metálico donde el fluido no está en equilibrio térmico con la fase sólida. Los coeficientes de transferencia de calor se obtienen a través del Single Blow Transient Method, combinando los resultados experimentales en un banco de ensayo con las soluciones numéricas del modelo matemático propuesto. El sistema de ecuaciones diferenciales parciales generado en el modelo matemático es resuelto a traves de una metodología numérica basada en el método de volúmenes finitos. Este modelo numérico fue construido en el software de la Dinámica de los Fluidos computacional CFX 4.3TM y se desarrollo en coordenadas cilíndricas axisimétricas usando un esquema de diferencias centrales para aproximar los términos difusivos un esquema híbrido para los términos conectivos y un esquema totalmente implícito para implementar el régimen transitorio. Las pruebas experimentales y las simulaciones numéricas se realizaron para diferentes valores de velocidad superficial del fluido a la entrada del lecho y para diferentes valores de porosidad del medio obteniéndose que los números de Nusselt dependen en gran escala de los números de Reynolds y la porosidad del medio, concordando satisfactorimente con los resultados de investigaciones similares

Clinical Benefits of On-Line Hemodiafiltration in ESRD Patients / 대한신장학회잡지

BACKGROUND: On-line hemodiafiltration (HDF) is a novel extracorporeal renal replacement therapy to increase the removal of middle molecules by convection and diffusion. This study was aimed to investigate the clinical benefit of on-line HDF. METHODS: Fifteen stable chronic renal failure patients who were maintaining on low-flux hemodialysis (HD) were switched to on-line HDF for 4 months. Blood pressure, solute clearance rate, anemia, nutrition, cardiac function, inflammatory markers, brain natriuretic peptide and subjective symptoms were compared. RESULTS: In the patients treated with HDF swiching from HD, the episode of intradialytic symptomatic hypotension was significantly decreased. In addition, KT/Vurea and urea reduction ratio as well as beta2-microglobulin clearance rate and reduction ratio were significantly increased, HDF treatment also decreased the pre-dialysis phosphorus levels and daily requirement of calcium carbonate. Furthermore, HDF treatment contributed to the reduction of erythropoietin dose to maintain similar hematocrit levels. Patients' dry weight was increased during HDF treatment without any change of serum albumin and nPCR levels. HDF treatment increased brain natriuretic peptide reduction ratio and improved subjective symptoms such as itching, headache, cramp and insomnia. Inflammatory markers such as hsCRP, IL-1beta, IL-6 and TNF-alpha were not changed by HDF treatment. CONCLUSION: Compared to conventional HD, on-line HDF may offer additional benefits with improved cardiovascular stability, enhanced middle molecule clearance, improvement of anemia and good control of subjective symptoms.

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 Renal Replacement Therapy in Pediatrics / 소아과

Continous renal replacement therapy(CRRT) is becoming increasingly popular for the support of critically ill patients with acute renal failure, and the development of pump-driven volumetric-control CRRT machines with small extracorporeal volumes has lead to the widespread use of venovenous form of CRRT in pediatric field. Basic principles are diffusion and convection. CRRT is indicated in the hemodynamically unstable pediatric patients for hypervolemic anuric acute renal failure, electrolyte abnormalities, multiorgan failure, catabolic patients with increased nutritional needs and hyperammonemia, etc. To date, experiences are limited for pediatric CRRT, but current reports support that CRRT is feasible and useful in children and even infants, and the survival rate of the patients on CRRT is as same as adults. We describe the basic principles, equipments, methods and complications of CRRT, with special considerations on small children to meet the current need for CRRT.

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.

The convection and diffusion of oxygen and carbon dioxide in the human airway / 生物医学工程学杂志

The convective-diffusive problems of oxygen and carbon dioxide in human airway at normal respiratory status were studied theoretically in the present paper. The human airway was idealized as a bifurcated(two-branch) trachea tree, based on the understanding of the physiological structure of the human airway, and on Horsfield-Wanner optimization analysis about the trachea system status. It was assumed that the gases in the airway were incompressible, viscous fluid, due mainly to the characteristics of the low pressure drop and low rate of the gases within the human airway. One dimensional, non-steady convective-diffusive equations of oxygen and carbon dioxide were solved using Lax-Wendroff finite difference method, i.e., the so called three-legged finite difference method. The boundary conditions were set up according to the two different situations, respectively. The computational results showed the reasonable distributions of the concentration of oxygen and carbon dioxide in the human airway, respectively.

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.