Effects of nutrient (N, P, K) fertilization on the dynamics of fine roots in tropical rain forests with different soil texture in the Colombian Pacific region / Efectos de la fertilización con nutrientes (N, P, K) sobre la dinámica de raíces finas en bosques húmedos tropicales con diferente textura del suelo en la región del Pacífico colombiano

Abstract Introduction: Fine root dynamics include production, turnover and decomposition; they are crucial to forest health, affect the entire biogeochemical complex of the ecosystem, and consequently, they substantially affect carbon balance. However, the influence of environmental factors and soil nutrient limitation on fine roots presents considerable uncertainties and has not been studied in tropical forests with more than 7 000 mm annual rainfall. Objective: To measure the effect of fertilization on fine roots in the high precipitation Chocó forest. Methods: We worked in two sites of the Chocó region, Colombia (August 2014-May 2015), where rainfall exceeds 10 000 mm per year. We applied five fertilization treatments (N, P, K, NPK and Control) to two soil type plots. Soil cylinders were removed at pre-established intervals to measure roots. Results: Phosphorus applications increased fined roots; and more fine roots were produced in sandy than in loam soil. The effects of fertilization were related, but not clearly determined by edaphic conditions. Conclusions: In this Chocó forest, the production of fine roots was higher in sandy and nutrient-rich soils but belowground net primary productivity was limited by the content of edaphic Phosphorus.

Resumen Introducción: La dinámica de las raíces finas incluye producción, rotación y descomposición; son cruciales para la salud de los bosques, afectan todo el complejo biogeoquímico del ecosistema y, en consecuencia, afectan sustancialmente el balance de carbono. Sin embargo, la influencia de los factores ambientales y la limitación de nutrientes del suelo en las raíces finas presenta incertidumbres considerables y no se ha estudiado en bosques tropicales con más de 7 000 mm de precipitación anual. Objetivo: Medir el efecto de la fertilización en las raíces finas en el bosque chocoano de alta precipitación. Métodos: Se trabajó en dos sitios de la región del Chocó, Colombia (agosto 2014-mayo 2015), donde las precipitaciones superan los 10 000 mm anuales. Se aplicaron cinco tratamientos de fertilización (N, P, K, NPK y Control) a dos parcelas por tipo de suelo. Los cilindros de suelo se retiraron a intervalos preestablecidos para medir las raíces. Resultados: Las aplicaciones de fósforo aumentaron las raíces finas; y se produjeron más raíces finas en suelos arenosos que en francos. Los efectos de la fertilización estuvieron relacionados, pero no claramente determinados por las condiciones edáficas. Conclusiones: En este bosque chocoano, la producción de raíces finas fue mayor en suelos arenosos y ricos en nutrientes, pero la productividad primaria neta subterránea estuvo limitada por el contenido de fósforo edáfico.

Research progress of continuous manufacturing and process knowledge system of traditional Chinese medicine / 中国中药杂志

In the past few years, continuous manufacturing(CM) has been put forward by the FDA. Pharmaceutical enterprises are encouraged to promote the implementation of CM, which has become a hot research direction of pharmaceutical technology. In February 2019, the FDA issued a draft guideline for the implementation of CM, which greatly promoted the development of CM and provided reference for continuous manufacturing of traditional Chinese medicine(TCM). The production process of TCM is a complex system. With the innovation of production equipment and the promotion of automation and informatization of TCM production, the exis-ting policies, regulations and traditional production control capacity are difficult to meet the market demand for high-quality TCM pro-ducts. In this paper, we reviewed the new technologies and methods of quality control in accordance with the characteristics of TCM production by referring to modern manufacturing technology, information technology and quality control technology. Based on the "QbD" theory and "PAT" technology, process knowledge system(PKS), an advanced control strategy, was proposed to provide a reference for the implementation of CM in TCM production.

Biodegradabilidad de lixiviados procedentes de un relleno sanitario utilizando un sistema de lodos activados flujo pistón / The biodegradability of leachates from a landfill using an activated sludge processes plug flow reactor system / Biodegradabilidade de lixiviados de um aterro usando um sistema de lodos ativados de fluxo de pistão

Resumen En esta investigación se desarrolló un Reactor Flujo Pistón (RFP) de lodos activados, que fue empleado para determinar el Tiempo de Retención Celular (TRC) óptimo para tratar cargas altas de lixiviado y estimar el comportamiento cinético del sistema con el fin que sirva de base para proyecciones de escalamiento y diseño de reactor de este tipo a escala real. Para ello se realizó el diseño, la construcción y puesta en marcha del RFP a nivel de laboratorio (capacidad de 50L) en condiciones de operación continua con recirculación de lodo y se utilizó como sustrato lixiviado procedente del relleno sanitario El Guayabal de la ciudad de Cúcuta. Se determinó como parámetros de control cuatro TRC diferentes entre 5 y 20 días diferenciada por etapas. Se evaluaron las variables de pH, Temperatura, Oxígeno disuelto y Sólidos Suspendidos Volátiles en el Licor Mixto (SSVLM). En cuanto al control y monitoreo de la eficiencia de remoción se escogió la Demanda Química de Oxígeno (DQO) como parámetro para medir la degradación de materia orgánica, dado que este parámetro a diferencia de la Demanda Bioquímica de Oxígeno (DBO5) puede ser calculado en un menor tiempo. El sistema biológico RFP alcanzó estabilizarse en un período de operación entre 20 y 25 días con remociones promedio mayores a 92% para TRC de 15 y 20 días mientras que TRC menores reportaron remociones promedio por debajo del 86%. Así mismo TRC de 15 permitió un Factor de carga (F/M) óptima promedio de 1.1 KgDQO/KgSSV.d. Las constantes cinéticas obtenidas en esta investigación, representativas para un sistema de RFP operado a escala laboratorio para remoción de materia orgánica carbonacea en lixiviados fueron: KS= 836.5 mg/L DQO, k=4.8123 d1, Y= 0.089 mg SSVLM/mg DQO y kd= 0.018 d-1, ajustados por regresión al modelo matemático de Lawrence y McCarty al poseer una correlación de 0.97 entre los datos experimentales obtenidos y el modelo y amplia aplicación en el campo de diseño de reactores de lodos activados.

Abstract An activated sludge processes (ASP) plug flow reactor (PFR) was developed in this research and used for determining optimal cell residence time (CRT) for treating high leachate loads and estimating the system's kinetic behaviour as a basis for scaling projections and this type of reactor design at full-scale. The RFP was designed, built and put into operation in the laboratory (50L capacity) involving continuous operation conditions with sludge recirculation; leached substrate from the city of Cúcuta's El Guayabal landfill was used. Four 5-day CRTs (ranging from 5 to 20 days) were used as control parameters. Variables were evaluated regarding pH, temperature, dissolved oxygen and mixed liquor volatile suspended solids (MLVSS). Regarding removal efficiency control and monitoring, chemical oxygen demand (COD) was chosen as a parameter for measuring organic matter degradation since COD (unlike biochemical oxygen demand (BOD5)) can be calculated in a shorter time. The RFP biological system became stabilised in a 20- to 25-day operating period, having greater than 92% average removal for 15- and 20-day CRTs, whilst lower CRTs reported lower than 86% average removal. A 15-day TRC gave an average 0.26 kgDQO/kgSSV.d optimal load factor (F/M). The representative kinetic constants obtained in this research for a laboratory-scale PFR system for the removal of carbonaceous organic matter in leachates were KS = 836mg COD / l, k = 4.8123 d1, Y = 0.089 mg SSVLM / mg COD and kd = 0.018 d-1, adjusted by regression using Lawrence and McCarty's mathematical model (having 0.97 correlation between the experimental data and the model). Such model should have broad application in the field of ASP-type PFRs.

Resumo Nesta pesquisa, um Reator de lodo ativado de Fluxo de Pistão (RFP) foi desenvolvido para determinar o Tempo de Retenção Celular (CRT) ideal para tratar altas cargas de lixiviado e estimar o comportamento cinético do sistema, a fim de servir de base para projetar o reator em escala real. Para isso, foram realizados RFP em nível de laboratório (capacidade de 50L) em condições de operação contínua com recirculação de lodo e foi utilizada como substrato lixiviado do aterro El Guayabal na cidade de Cúcuta. Usando quatro diferentes CRTs entre 5 e 20 dias como fatores de bloqueio. Foram avaliadas as variáveis ​​pH, Temperatura, Oxigênio Dissolvido e Sólidos Suspensos Voláteis no Licor Misto (SSVLM). Em relação ao controle e monitoramento da eficiência de remoção, a Demanda Química de Oxigênio (DQO) foi escolhida como parâmetro para medir a degradação da matéria orgânica, uma vez que este parâmetro, ao contrário da Demanda Bioquímica de Oxigênio (DBO5), pode ser calculado em um tempo mais curto. O sistema biológico da RFP se estabilizou em um período de operação entre 20 e 25 dias com remoções médias superiores a 92% para TRC de 15 e 20 dias, enquanto TRC menores mostraram remoções médias abaixo de 86%. Da mesma forma, TRC de 15 dias permitiu um fator de carga ideal médio (F / M) de 0,26 KgDQO / d. As constantes cinéticas obtidas nesta pesquisa, representativas de um sistema RFP operado em escala de laboratório para remoção de matéria orgânica carbonácea em lixiviados foram: KS = 836mg COD / l, k = 4,8123 d1, Y = 0,089 mg SSVLM / mg COD e kd = 0,018 d-1, ajustado por regressão ao modelo matemático de Lawrence e McCarty, tendo uma correlação de 0,97 entre os dados experimentais obtidos e o modelo e ampla aplicação na área de projeto de reatores de lodo ativado.

Características de pacientes con alta clínica post SARS-Cov-2 hospitalizados en EsSalud. Región Lambayeque / Original Characteristics of clinic discharge patients with SARS-Cov-2 hospitalized at EsSalud in the Lambayeque Region

Introducción. La pandemia por Covid 19 ha ocasionado alta letalidad en la región Lambayeque colapsando los hospitales. Objetivos: Describir según genero las características de pacientes con alta clínica post Sars.Cov2 hospitalizados en Essalud de la Región Lambayeque. Material y Métodos: Estudio observacional, retrospectivo, descriptivo, seleccionando una muestra representativa de los casos confirmados COVID 19 entre el 01 de abril al 30 de junio del 2020 en el Hospital Nacional Almanzor Aguinaga Asenjo (HNAAA) y Hospital Luis Heysen Inchaustegui (HLHI); como criterios de exclusión: Aquellos con menos de 48 horas de estancia, los fallecidos y los referidos a otros establecimientos. Se recolectaron los datos de historia clínica en el sistema SGSS, se utilizó el software Excel para el procesamiento de datos. Resultados: se registraron 329 pacientes de los cuales 70% fueron varones, promedio de edad 55,9 +/- 11 años; el diagnóstico fue mediante prueba serológica 80% y Tomografía de tórax 17%. La disnea fue el síntoma predominante 85%, linfopenia 51% y proteína C reactiva alta 39% y LDH alta 35%. El tratamiento fue principalmente oxígeno 89% y enoxaparina 87%, azitromicina 86% y ceftriaxona 70%, las complicaciones hospitalarias fueron el SDRA 88,1% y la neumonía atípica 86,6%, la estancia en hospitalización fue de 7,85 +/- 5,42 días. Conclusiones: La mayoría de hospitalizados en Essalud fueron varones, promedio edad 55,9 años; síntoma principal disnea; predominó la linfopenia con proteína C reactiva y LDH altas; el tratamiento fue en base a oxígeno, y enoxaparina, promedio de estancia en hospitalización de 7,85 días.

Introduction.The Covid 19 pandemic has caused high lethalityintheLambayequeregion,collapsing hospitals.Objectives:describe,bygender,the characteristics of clinic discharge patients with sars-cov2 hospitalized at EsSalud in the Lambayeque region. Material and Methods:Observational, retrospective, descriptive study, selecting a representative sample of confirmed COVID 19 cases between April 1 to June 30, 2020 at the Almanzor Aguinaga Asenjo National Hospital (HNAAA) and the Luis Heysen Inchaustegui Hospital (HLHI) ; as exclusion criteria: those with less than 48 hours of stay, the deceased and those referred to other establishments.Theclinicalhistorydatawere collected in the SGSS system, Excel software was used fordataprocessing.Results:329patientswere registered, of which 70% were male, mean age 55.9 +/- 11 years; Diagnosis was by serological test 80% and chest tomography 17%. Dyspnea was the predominant symptom 85%, lymphopenia 51% and high C-reactive protein 39% and high LDH 35%. Treatment was mainly oxygen 89% and enoxaparin 87%, azithromycin 86% and ceftriaxone 70%, hospital complications were ARDS 88.1% and atypical pneumonia 86.6%, hospital stay was 7.85 + / - 5.42 days. Conclusions:The majority of hospitalized in Essalud were men, average age 55.9 years; main symptom dyspnea; lymphopenia with high C-reactiveproteinandLDHpredominated;the treatment was based on oxygen and enoxaparin, mean hospital stay of 7.85 days.

Formulation And In-Vitro Evaluation Of Theophylline Hydrochloride Effervescent Floating Tablets: Effect Of Polymer Concentration On Tablet Buoyancy

Objective: This study was undertaken to formulate a floating drug delivery system of theophylline hydrochloride using different concentrations of a chosen polymer and then investigate how polymer concentration affects buoyancy and drug release properties of the tablets. Methods: Hydroxypropyl methylcellulose (HPMC) at different concentration levels of 15% (F1), 20% (F2) and 30% (F3) was used to form the three formulation batches of floating tablets. Wet granulation method was used for the granule preparation while Sodium bicarbonate and citric acid were used as the gas generating agent. The physical properties of the granules and the floating tablets were evaluated. Also determined were the physicomechanical properties, buoyancy and swelling characteristics of the tablets. The in vitro drug release study was carried out according to the USP I (basket method) for 8h in 900 ml 0.1N HCl at 50 rpm. Samples withdrawn at the regular predetermined time were analyzed spectrophotometrically at a wavelength of 271 nm and data obtained statistically analyzed by one-way analysis of variance (ANOVA). The differences between means were considered significant at P<0.05. Results: The result showed that polymer (HPMC) concentration significantly (p>0.05) increased swelling index and improved floating lag time, it had no significant effect on the total floating time. Percentage drug release at the end of 8 h was 100%, 98.2% and 96.13% for formulation F1, F2 and F3, respectively. All three formulations followed the Higuchi drug release kinetics model and the mechanism of drug release was the non Fickian diffusion with exponents of 0.46, 0.51 and 0.56 for the respective batch. Conclusion: Batch F3 gave a better-controlled drug release and floating properties in comparison to batch F1 and F2 thus Polymer concentration influenced the onset of floating and controlled the release of Theophylline.

On the origin and residence time of water in the Lima aquifer / Origen y tiempo de residencia del agua en el acuífero de Lima

Abstract Lima, the capital of Peru, and Callao form one of the largest urban centers in South America, with a total population of 10.9 million as of 2017. Three rivers supply water to Lima; however, water for municipal use is mainly taken from the Rimac and Chillon Rivers. Correlating the historic of Rimac flow with the static level of a well in Miraflores, 1 km from Pacific Ocean, was estimated that the residence time, this is the time passing after water infiltrates the ground during a rainfall event until it reaches the Miraflores well, is three years, which agrees with the permeability of the valley, which is in the order of 10-4 ms-1. The average age of water from Lima wells is 6 years, which is consistent with the hypothesis that wells have water from several soil shells. In other hand, the relative abundance of 2H and 18O in wells in the Lima aquifer are in agreement with the hypothesis that the aquifer is recharged with water from rainfall events that occur in the highlands between 3000 and 5000 m above sea level (a.s.l). The contents of 2H,18O, Ca and SO4 of the Graton tunnel sample suggest that it corresponds to water coming from altitudes of 4500 m a.s.l.

Resumen Lima, la capital de Perú, y Callao forman uno de los centros urbanos más grandes de América del Sur, con una población total de 10.9 millones en 2017. Tres ríos abastecen de agua a Lima; sin embargo, el agua para los municipios se toma principalmente de los ríos Rímac y Chillón. Correlacionando el flujo histórico del Rímac con el nivel estático de un pozo en Miraflores, a 1 km del océano Pacífico, se calculó que el tiempo de residencia, esto es el tiempo que transcurre después de que el agua se infiltra en el suelo durante un evento de lluvia, hasta que llega a dicho pozo, es de tres años, lo que está de acuerdo con la permeabilidad del valle, que es del orden de 10-4ms-1. La edad promedio del agua de los pozos de Lima es de 6 años, lo que es consistente con la hipótesis de que los pozos tienen agua de varias capas de suelo. Por otro lado, la abundancia relativa de 2H y 18O en los pozos del acuífero de Lima está de acuerdo con la hipótesis de que el acuífero se recarga con agua de los eventos de lluvia que ocurren en las tierras altas entre 3000 y 5000 m. sobre el nivel del mar (s.n.m). El contenido de 2H, 18O, Ca y SO4 de la muestra del túnel Graton (3100 m.s.n.m.) sugiere que corresponde al agua proveniente de altitudes de 4500 m.s.n.m.

Análise da permanência em maternidade hospitalar / Analysis of staying in hospital maternity

Pesquisa documental, descritiva e quantitativa que objetivou identificar a permanência de pacientes hospitalizadas na maternidade de um hospital universitário público...

Documentary, descriptive and quantitative research that aimed to identify the permanence of hospitalized patients in the maternity hospital of a public university hospital...

Investigación documental, descriptiva y cuantitativa que objetivó identificar la permanencia de pacientes hospitalizados en la maternidad de un hospital universitario público...

Survey of HIV infection in men who have sex with men living for 5 years or less in Wenzhou,Zhejiang province / 中华流行病学杂志

Objective To assess the prevalence of HIV infection and related factors in men who have sex with men (MSM) living for ≤5 years in Wenzhou of Zhejiang province.Methods MSM who were aged ≥ 16 years,had lived in Wenzhou for ≥3 months and had anal sex and/or oral sex with men in the last 12 months were recruited through respondent-driven sampling (RDS) from February to October in 2015.The MSM recruited completed a questionnaire for the information collection on socio-demographic characteristics,sexual behavior,awareness of HIV and related intervention,mental health status.Blood samples were collected from them for serological detection of HIV and syphilis antibodies.Software SPSS 18.0 was used to analyze HIV infection and related factors.Results A total of 454 MSM were investigated,108 of them (23.7％) were HIV positive.There were 267 MSM who lived in Wenzhou for ≤5 years,and 73 of them (27.3％) were HIV positive.Most of them were workers and commercial servants aged ≥ 25 years with personal monthly income ＜4 000 yuan and educational level of junior high school or below.According to multiple logistics regression analysis,age of 25-68 years old (OR=12.19,95％CI:2.29-65.02),heterosexual behavior in recent 6 months (OR=0.42,95％CI:0.18-0.96),believing it was possible to be infected with HIV (OR=0.06,95％CI:0.01-0.95),believing it was impossible to be infected with HIV (OR=0.03,95％CI:0.01-0.35) and syphilis status (OR=3.32,95％CI:1.05-10.52) were the risk factors associated with HIV infection.Conclusion Compared with MSM who lived in Wenzhou for ＞ 5 years,MSM who lived in Wenzhou for ≤ 5 years had higher HIV infection rate and higher prevalence of risk behavior.It is necessary to conduct targeted intervention among them.

Survey of HIV infection in men who have sex with men living for 5 years or less in Wenzhou,Zhejiang province / 中华流行病学杂志

Objective To assess the prevalence of HIV infection and related factors in men who have sex with men (MSM) living for ≤5 years in Wenzhou of Zhejiang province.Methods MSM who were aged ≥ 16 years,had lived in Wenzhou for ≥3 months and had anal sex and/or oral sex with men in the last 12 months were recruited through respondent-driven sampling (RDS) from February to October in 2015.The MSM recruited completed a questionnaire for the information collection on socio-demographic characteristics,sexual behavior,awareness of HIV and related intervention,mental health status.Blood samples were collected from them for serological detection of HIV and syphilis antibodies.Software SPSS 18.0 was used to analyze HIV infection and related factors.Results A total of 454 MSM were investigated,108 of them (23.7％) were HIV positive.There were 267 MSM who lived in Wenzhou for ≤5 years,and 73 of them (27.3％) were HIV positive.Most of them were workers and commercial servants aged ≥ 25 years with personal monthly income ＜4 000 yuan and educational level of junior high school or below.According to multiple logistics regression analysis,age of 25-68 years old (OR=12.19,95％CI:2.29-65.02),heterosexual behavior in recent 6 months (OR=0.42,95％CI:0.18-0.96),believing it was possible to be infected with HIV (OR=0.06,95％CI:0.01-0.95),believing it was impossible to be infected with HIV (OR=0.03,95％CI:0.01-0.35) and syphilis status (OR=3.32,95％CI:1.05-10.52) were the risk factors associated with HIV infection.Conclusion Compared with MSM who lived in Wenzhou for ＞ 5 years,MSM who lived in Wenzhou for ≤ 5 years had higher HIV infection rate and higher prevalence of risk behavior.It is necessary to conduct targeted intervention among them.

Analysis on status and determinants of outpatient service utilization of rural floating population in Beijing at different residence time / 北京大学学报(医学版)

Objective: To study the status and identify the determinants of outpatient service utilization of rural floating population in Beijing who have different accumulated residence time.Methods: The survey data of rural floating population health and health care services in Beijing in 2014 were used, and the migrant population aged 18 years and above were taken as the research object.Whether to use outpatient service within two weeks was taken as dependent variable, gender, age, education level, self-assessment score of socioeconomic status, accumulated residence time in Beijing, health insurance, average household income, suffering from high blood pressure or diabetes as independent variables.Logistic regression model was used to analyze the influencing factors.Results: The average age of the research object was 36.7 years, with mostly secondary education.The average accumulated residence time in Beijing was 8.4 years.The two-week prevalence rate was 10.3%, the two-week visiting rate calculated by person-time was 6.0%.The Logistic regression model suggested that, socioeconomic status, accumulated residence time and suffering from high blood pressure or diabetes were statistically significant determinants of outpatient service utilization.Conclusion: The research object is a younger and less educated population, their health status is better and outpatient service utilization is lower.It is found that people who have longer accumulated residence time in Beijing have lower outpatient service utilization.This is because people with longer residence time have lower age-adjusted two-week prevalence rate.This is also because people with longer residence time have larger proportion of taking continuous measures under doctor's advice.It does not mean people with longer residence time have lower utilization of medical service.The residence time variable plays the role of proxy variable.It can solve the problem of variables' endoge-neity.At the same time, it can reflect the influence to outpatient services utilization of some determinants,which are not included in the model but varies with residence time.

New perspectives on the computational characterization of the kinetics of binding-unbinding in drug design: implications for novel therapies / Nuevas perspectivas sobre la caracterización computacional de la cinética de unión-desunión en el diseño de fármacos: implicaciones para terapias de vanguardia

Abstract: The efficiency and the propensity of a drug to be bound to its target protein have been inseparable concepts for decades now. The correlation between the pharmacological activity and the binding affinity has been the first rule to design and optimize a new drug rationally. However, this argument does not prove to be infallible when the results of in vivo assays have to be confronted. Only recently, we understand that other magnitudes as the kinetic rates of binding and unbinding, or the mean residence time of the complex drug-protein, are equally relevant to draw a more accurate model of the mechanism of action of a drug. It is in this scenario where new computational techniques to simulate the all-atom dynamics of the biomolecular system find its valuable place on the challenge of designing new molecules for more effective and less toxic therapies.

Resumen: La eficiencia de un fármaco se ha relacionado habitualmente con su constante de afinidad, magnitud que puede ser medida experimentalmente in vitro y que cuantifica la propensión mostrada por la molécula ligando para interaccionar con su proteína diana. Este modo de entender el mecanismo de acción ha guiado durante años el desarrollo de nuevas moléculas con potencial farmacológico. Sin embargo, dicho modelo o criterio no es infalible cuando se confronta con los resultados de ensayos in vivo. Otras magnitudes, como las constantes cinéticas de asociación o disociación o el tiempo de residencia del ligando acoplado a su proteína diana, demuestran ser igualmente necesarias para comprender y predecir la capacidad farmacológica del compuesto químico. En este nuevo escenario, con ayuda de las técnicas computacionales de simulación molecular, la correcta caracterización del proceso dinámico de unión y desunión del ligando y receptor resulta imprescindible para poder diseñar racionalmente nuevas moléculas que permitan terapias más eficaces y menos tóxicas.

Water residence time affecting phytoplankton blooms: study case in Ibitinga Reservoir (São Paulo, Brazil) using Landsat/TM images / Efeito de variações no tempo de residência hidráulica sobre a ocorrência de florações de fitoplâncton: estudo de caso no Reservatório de Ibitinga (SP) com o uso de imagens Landsat/TM

Abstract Satellite images are an effective tool for the detection of phytoplankton blooms, since they cause striking changes in water color. Bloom intensity can be expressed in terms of chlorophyll-a concentration. Previous studies suggest the use of Landsat TM4/TM3 reflectance ratio to retrieve surface chlorophyll-a concentration from aquatic systems. In this study we assumed that a remote sensing trophic state index can be applied to investigate how changes in HRT along the hydrologic year affect the spatial distribution of the phytoplankton blooms at Ibitinga’s reservoir surface. For that, we formulated two objectives: (1) apply a semi-empirical model which uses this reflectance ratio to map chlorophyll-a concentration at Ibitinga reservoir along the 2005 hydrologic year and (2) assess how changes in hydraulic residence time (HRT) affect the spatial distribution of phytoplankton blooms at Ibitinga Reservoir. The study site was chosen because previous studies reported seasonal changes in the reservoir limnology which might be related to the reservoir seasonality and hydrodynamics. Six Landsat/TM images were acquired over Ibitinga reservoir during 2005 and water flow measurements provided by the Brazilian Electric System National Operator - ONS were used to compute the reservoir´s residence time, which varied from 5.37 to 52.39 days during 2005. The HRT in the date of image acquisition was then compared to the distribution of chlorophyll-a in the reservoir. The results showed that the HRT increasing implies the increasing of the reservoir surface occupied by phytoplankton blooms.

Resumo As imagens de satélite são frequentemente usadas para a identificação de florações de fitoplâncton porque sua presença causa mudanças significativas na cor da água. A abundância das florações pode ser quantificada por medidas de concentração de clorofila-a. Diversos estudos sugerem o uso da razão de reflectância das bandas TM4/TM3 Landsat, para determinar as concentrações de clorofila-a em sistemas aquáticos. Este trabalho tem como objetivos: (1) aplicar um modelo semi-empírico que usa essa razão para mapear a concentração de clorofila-a no reservatório de Ibitinga ao longo do ano hidrológico de 2005; (2) avaliar como as mudanças no tempo de residência hidráulica afetaram a distribuição de florações na superfície do reservatório. O reservatório de Ibitinga foi selecionado porque estudos prévios indicavam mudanças sazonais nas propriedades limnológicas do reservatório, as quais poderiam estar relacionadas à sazonalidade e à hidrodinâmica. Seis imagens TM/Landsat foram adquiridas sobre o reservatório de Ibitinga durante o ano de 2005. Foi então usada uma tabela associando intervalos de razão de banda a intervalos de concentração de clorofila-a. Medidas de vazão fornecidas pelo Operador Nacional do Sistema Elétrico – ONS foram utilizadas para calcular o tempo de residência hidráulica do reservatório, que variou entre 5,37 e 52,39 dias durante 2005. O tempo de residência hidráulica em cada data de aquisição da imagem foi então comparado com a área ocupada pelas florações de fitoplancton. Os resultados indicaram uma forte relação entre o tempo de residência hidráulica e a área ocupada por florações. Em junho de 2005, quando o reservatório atingiu seu menor tempo de residência hidráulica, apenas 20% de sua área estiveram ocupadas por florações. Em setembro e outubro, quando a residência hidráulica atinge o seu máximo, mais que 80% da superfície do reservatório foram ocupadas por florações de fitoplancton.

Contact lenses as drug controlled release systems: a narrative review / As lentes de contacto como sistema de libertação controlada de fármacos: uma revisão narrativa

ABSTRACT Topically applied therapy is the most common way to treat ocular diseases, however given the anatomical and physiological constraints of the eye, frequent dosing is required with possible repercussions in terms of patient compliance. Beyond refractive error correction, contact lenses (CLs) have, in the last few decades emerged as a potential ophthalmic drug controlled release system (DCRS). Extensive research is underway to understand how to best modify CLs to increase residence time and bioavailability of drugs within therapeutic levels on the ocular surface.These devices may simultaneously correct ametropia and have a role in managing ophthalmic disorders that can hinder CL wear such as dry eye, glaucoma, ocular allergy and cornea infection and injury. In this narrative review the authors explain how the ocular surface structures determine drug diffusion in the eye and summarize the strategies to enhance drug residence time and bioavailability. They synthesize findings and clinical applications of drug soaked CLs as DCRS combined with delivery diffusion barriers, incorporation of functional monomers, ion related controlled release, molecular imprinting, nanoparticles and layering. The authors draw conclusions about the impact of these novel ophthalmic agents delivery systems in improving drug transport in the target tissue and patient compliance, in reducing systemic absorption and undesired side effects, and discuss future perspectives.

RESUMO A forma mais frequente de aplicação terapêutica em oftalmologia consiste na instilação de gotas oculares, mas dadas as limitações anatómicas e fisiológicas do olho, é necessária dosagem frequente com possível repercussão na adesão do paciente à terapêutica. Nas últimas décadas, as lentes de contacto (CLs) têm surgido como um potencial sistema de libertação controlada de fármacos na superfície ocular (DCRS) para correção do erro refrativo. Está em curso uma extensa investigação para entender a melhor forma de modificar as CLs, de modo a aumentar o tempo de residência e a biodisponibilidade do medicamento na superfície ocular dentro de níveis terapêuticos. Ao corrigirem a ametropia, estes dispositivos poderão simultaneamente desempenhar um papel na gestão de perturbações oftalmológicas, tais como a síndrome do olho seco, glaucoma, alergia ocular e infecção corneana, que podem comprometer o porte seguro e confortável das CLs. Nesta revisão narrativa, os autores explicam como as estruturas da superfície ocular determinam a difusão de fármacos no olho e sintetizam as estratégias para aumentar a permanência e biodisponibilidade dos mesmos. Em seguida, apresentam os resultados e as aplicações clínicas das CLs embebidas em fármacos, como DCRS, através da incorporação de barreiras de difusão, de monómeros funcionais, da liberação controlada por iões, da impressão molecular, de nanopartículas e pelo processo camada sobre camada. Os autores concluem avaliando o impacto destes novos sistemas de entrega de agentes farmacológicos ao melhorar o seu transporte no tecido alvo, reduzindo a sua absorção sistémica e os seus efeitos colaterais indesejáveis, e discutem perspectivas futuras.

Vulnerabilidade à eutrofização de dois lagos tropicais de climas úmido (Cuba) e semiárido (Brasil) / Vulnerability towards eutrophication of two tropical lakes in both humid (Cuba) and semiarid (Brazil) climates

RESUMO: Este artigo compara o estado de eutrofização e suas prováveis causas em dois reservatórios tropicais, um em clima úmido (La Juventud, Cuba) e o outro em clima semiárido (Marengo, Brasil). Após estimar o estado trófico dos dois reservatórios nas estações chuvosa e seca, avaliou-se a influência hidrológica e de uso do solo sobre o grau de trofia dos lagos. Concluiu-se que os lagos são, em média, mesotróficos. Porém, o lago tropical semiárido encontra-se eutrófico, enquanto que o úmido está oligotrófico. Considerando que há similitude entre os usos do solo nas duas bacias e que, na estação chuvosa, o aporte de nutrientes na bacia úmida é consideravelmente superior ao da semiárida, o maior estado trófico da bacia seca surpreende. A variável que melhor explica esse fenômeno é o tempo de residência da água, que influencia diretamente o tempo de residência do fósforo no lago. O elevado tempo de residência da água na bacia semiárida (três vezes superior ao do lago úmido) deve-se tanto ao reduzido coeficiente de escoamento superficial (93 versus 595 mm anuais na bacia úmida) quanto à excessiva evaporação da água armazenada no reservatório seco (quatro vezes superior à do reservatório úmido). Esses resultados indicam que lagos semiáridos são mais vulneráveis à eutrofização que os úmidos nos períodos de estio e que, portanto, o manejo de suas bacias deve ser mais restritivo à produção de nutrientes.

ABSTRACT: This manuscript compares the eutrophication status and its possible causes in two tropical reservoirs, one in humid climate (La Juventud, Cuba) and the other in semi-arid climate (Marengo, Brazil). After estimating the trophic state of the two reservoirs in rainy and dry seasons, we evaluated the influence of hydrology and of land use on reservoir trophic level. It was found that the semi-arid tropical reservoir was eutrophic, while the reservoir on humid climate was mesotrophic. Considering that there is similar land use in the two basins and that, in the rainy season, the nutrient input in the wet basin is considerably higher than the nutrient input in the semiarid basin, the higher trophic state of the semi-arid basin is surprising. The variable that best explains this phenomenon is the water residence time, which directly influences the phosphorus residence time in the reservoir. The high water residence time in the semiarid basin reservoir (three times that of the reservoir in humid climate) is due as much to the low runoff coefficient (93 versus 595 mm per year in the reservoir in humid climate) as to the excessive water evaporation in the semiarid reservoir (1.2 times that of the reservoir in humid climate). These results indicate that semiarid reservoirs are more vulnerable to eutrophication than reservoirs in humid climate in summer periods and, therefore, the management of their basins should be more restrictive to nutrient production.

Development of a new single unit dosage form of propranolol HCl extended release non-effervescent floating matrix tablets: In vitro and in vivo evaluation.

The objective of the present investigation was to develop extended release non-effervescent floating matrix tablets of Propranolol Hydrochloride (PPH) to extend the gastric residence time (GRT) and prolong the drug release after oral administration. Different viscosity grades of Hydroxypropyl methylcellulose (HPMC) polymers such as HPMC K4M, HPMC K15M and HPMC K100M were used as drug release retardants. Glyceryl behinate (Compritol 888 ATO) and Glyceryl monosterate (Precirol ATO 5) were used as low density lipids in order to get the desired buoyancy over a prolonged period of time. The drug excipients compatibility study was carried out by using Differential Scanning Calorimetry (DSC). All the formulations were prepared by direct compression technique. The prepared tablets were evaluated for their physical characters, in vitro drug release and in vitro buoyancy. The release and floating property depends on the polymer type, polymer proportion, lipid type and lipid proportions. The drug release profiles of all the formulations were subjected to Zero order, First order, Higuchi and Peppas kinetic models, and the optimized formulation (F7) followed the Peppas model (R2= 0.987) with non-Fickian diffusion mechanism(n>0.5). The optimized formulation was subjected for in vivo radiographic studies in healthy human volunteers (n=3). These studies revealed a mean gastric residence time of 5±1.73 h (n=3).

A review on gastroretentive drug delivery system.

Oral controlled release and site specific drug delivery system has been of great interest in pharmaceutical field to achieve improved therapeutic advantage. Concept of novel drug delivery system arose to overcome certain aspect related to physicochemical properties of drug molecule and the related formulations. Gastro retentive drug delivery system is one of such novel approaches to prolong gastric residence time, thereby targeting site specific drug release in the stomach for local or systemic effects. This approach is useful particularly for the drugs which have narrow absorption window in the upper part of gastro intestinal tract. In this review we have been discussed various approaches of gastro retentive drug delivery system, such as floating and non-floating systems.

Estimation of radiation dose to patients from 18FDG whole body PET/CT investigations using dynamic PET scan protocol.

Background & objectives: There is a growing concern over the radiation exposure of patients from undergoing 18FDG PET/CT (18F-fluorodeoxyglucose positron emission tomography/computed tomography) whole body investigations. The aim of the present study was to study the kinetics of 18FDG distributions and estimate the radiation dose received by patients undergoing 18FDG whole body PET/CT investigations. Methods: Dynamic PET scans in different regions of the body were performed in 49 patients so as to measure percentage uptake of 18FDG in brain, liver, spleen, adrenals, kidneys and stomach. The residence time in these organs was calculated and radiation dose was estimated using OLINDA software. The radiation dose from the CT component was computed using the software CT-Expo and measured using computed tomography dose index (CTDI) phantom and ionization chamber. As per the clinical protocol, the patients were refrained from eating and drinking for a minimum period of 4 h prior to the study. Results: The estimated residence time in males was 0.196 h (brain), 0.09 h (liver), 0.007 h (spleen), 0.0006 h (adrenals), 0.013 h (kidneys) and 0.005 h (stomach) whereas it was 0.189 h (brain), 0.11 h (liver), 0.01 h (spleen), 0.0007 h (adrenals), 0.02 h (kidneys) and 0.004 h (stomach) in females. The effective dose was found to be 0.020 mSv/MBq in males and 0.025 mSv/MBq in females from internally administered 18FDG and 6.8 mSv in males and 7.9 mSv in females from the CT component. For an administered activity of 370 MBq of 18FDG, the effective dose from PET/CT investigations was estimated to be 14.2 mSv in males and 17.2 mSv in females. Interpretation & conclusions: The present results did not demonstrate significant difference in the kinetics of 18FDG distribution in male and female patients. The estimated PET/CT doses were found to be higher than many other conventional diagnostic radiology examinations suggesting that all efforts should be made to clinically justify and carefully weigh the risk-benefit ratios prior to every 18FDG whole body PET/CT scan.

Pacientes de cuidados intensivos em leito de retaguarda na recuperação pós-anestésica / Pacientes en cama de cuidados intensivos en recuperación posterior postanestésica / Patients in intensive care bed in rear recovery postanesthetic

Objetivo: Identificar o tempo de permanência e as principais dificuldades na assistência de enfermagem a pacientes graves em leito de retaguarda na Recuperação Pós-Anestésica. Método: Trata-se de um relato de experiência da pesquisadora enquanto enfermeira da Recuperação Pós-Anestésica deum hospital universitário na zona sul da cidade de São Paulo. Resultados: Em 12 meses, foram admitidos 8.395 pacientes, sendo que 129 eram pacientes graves que permaneceram em leito de retaguarda em média por 41,4 horas aguardando liberação de leitos na unidade de terapia intensiva. As dificuldades na assistência se referem à admissão, diluição e instalação de drogas em bombas de infusão, mudança de decúbito, banho no leito, administração de dieta, curativos, sondagens, e transporte para exames. Conclusão: Ressalta-se a necessidade da utilização adequada do setor para a recuperação pós-operatória dos pacientes, e que a presença de pacientes graves em leito de retaguarda requer adequação do quadro de profissionais em número e especificidade.

Objetivo: Identificar la duración de la estancia y de las principales dificultades en la atención de enfermería de los pacientes críticamente enfermos en cama Anestésico Recuperación. Método: se trata de un relato de experiencia de un investigador, mientras que la enfermera Publicar Anestésico Recuperación de un hospital universitario de la ciudad del sur de São Paulo. Resultados: 12 meses 8.395 pacientes fueron ingresados , de los cuales 129 eran pacientes graves que se quedaron en la cama trasera en un promedio de 41,4 horas a la espera de la liberación de camas en la unidad de cuidados intensivos. Las dificultades en la asistencia se refiere a la admisión, la dilución y la instalación de bombas de infusión de medicamentos, posiciones cambiantes, baño en la cama, la administración de la dieta, la curación, las encuestas, y el transporte para los exámenes. Conclusión: Hacemos hincapié en la necesidad de un uso adecuado de sector para la recuperación postoperatoria de los pacientes, y que la presencia de los pacientes críticamente enfermos en la cama trasera requiere una adaptación del personal profesional en número y especificidad.

Objective: To identify the length of stay and the main difficulties in the nursing care of critically ill patients in bed in rear Post Anesthetic Care Unit. Method: it is an experience report of a researcher while Nurse Post Anesthetic Recovery of a university hospital in the southern city of São Paulo. Results: In 12 months 8,395 patients were admitted, of which 129 were severe patients who remained in the rear bed on average by 41.4 hours awaiting release of beds in the intensive care unit. Difficulties in assisting refer to admission, dilution and installation of drug infusion pumps, changing positions, bed bath, administration of diet, healing, polls, and transportation for exams. Conclusion: We emphasize the need for appropriate use of sector for post-operative recovery of patients, and that the presence of critically ill patients in rear bed requires adaptation of the professional staff in number and specificity.

Bioadhesive buccal gels impregnated with fluconazole: formulation, in vitro and ex vivo characterization.

This study describes the formulation of bioadhesive buccal gels for fluconazole delivery via buccal mucosa. In the present study the polymer with well-defined mucoadhesive properties like Carbopol 934 was used. Carbopol- Poloxamer gels of 1% fluconazole was formulated with various absorption enhancers like polyethylene glycol, propylene glycol, glycerol, phosphatidylcholine, mannitol and sodium lauryl sulphate by cold method. The gels were characterised for gelation temperature, bioadhesive force, pH, viscosity, drug release profile, ex vivo permeation across goat buccal mucosa and stability profile. The percent drug permeated through the buccal mucosa was in the range of 62-76%. Polyethylene glycol and propylene glycol were found to be better absorption enhancers as compared to others and followed zero order release kinetics.

An algorithmic method for mean residence time in central compartment / 中国药学杂志

OBJECTIVE: To provide a method for calculating mean residence time of drugs in central compartment (MRTC).