Reflections on the fundamental nature of homeopathic potencies: Plasma, Langmuir Adsorption and Vitalism

There is a pressing need to develop methods and approaches that will identify the fundamental nature of homeopathic potencies. Aims: To bring together recent basic research on potencies, especially that using solvatochromic dyes, and to supplement these results with reliable observations made by Hahnemann and his contemporaries from the very beginnings of homeopathy, together with a detailed examination of the process of trituration and succussion coupled to dilution, in order to significantly limit the number of possible explanations as to the identity of potencies. Methodology: A mixture of lab based and literature studies such that as far as possible all verified and substantiated observations about homeopathic potencies have been examined. Results and Discussion: An understanding of the fundamental nature of homeopathic potencies that includes all known and accepted observations (in vitro, in vivoand clinical) is not realistic without embracing hypotheses involving the emergent properties of complex systems and in particular, vitalistic concepts. Using a vitalistic model it is possible to explain a wide range of seemingly unrelated phenomena -such as the polarising effect of potencies on solvatochromic dyes, the ability to use a range of materials such as water, lactose and cellulose as carriers of potencies, the administering of potencies by olfaction, the antidoting effect of camphor on potency action, the non-linear dependence of potency strength on volume as well as succussion level, the oscillatory behaviour of potencies and experimenter/observer/practitioner effects. Conclusion: A hypothesis in which homeopathic potencies can be seen as self-actuating and autonomous plasma generated by trituration and/or succussion and carried according to Langmuir adsorption models fits the known observations about potencies.

Characterization of the biosorption of fast black azo dye K salt by the bacterium Rhodopseudomonas palustris 51ATA strain

BACKGROUND: Removal of dyes from wastewater by microorganisms through adsorption, degradation, or accumulation has been investigated. Biological methods used for dye treatment are generally always effective and environmentally friendly. In this study, biosorption of the Fast Black K salt azo dye by the bacterium Rhodopseudomonas palustris 51ATA was studied spectrophotometrically, at various pH (2­10), temperatures (25°C, 35°C, and 45°C) and dye concentrations (25­400 mg L-1). RESULTS: The bacterial strain showed extremely good dye-removing potential at various dye concentrations. IR studies at different temperatures showed that the dye was adsorbed on the bacterial surface at lower temperatures. Characteristics of the adsorption process were investigated by Scatchard analysis at 25°C and 35°C. Scatchard analysis of the equilibrium binding data for the dye on this bacterium gave rise to linear plots, indicating that the Langmuir model could be applied. The regression coefficients obtained for the dye from the Freundlich and Langmuir models were significant and divergence from the Scatchard plot was observed. CONCLUSION: The adsorption behavior of the dye on this bacterium was expressed by the Langmuir, Freundlich, and Temkin isotherms. The adsorption data with respect to various temperatures provided an excellent fit to the Freundlich isotherm. However, when the Langmuir and Temkin isotherm models were applied to these data, a good fit was only obtained for the dye at lower temperatures, thus indicating that the biosorption ability of R. palustris 51ATA is dependent on temperature, pH, and dye concentration.

Cinética de la adsorción de fluoruro y arsénico usando nano-fibras de alúmina / Kinetics of the fluoride and arsenic adsorption using alumina nanofibers

Resumen En muchos países del mundo, incluido México, la presencia de elementos tóxicos, como el arsénico y flúor por encima de los niveles máximos permitidos en el agua potable (0.01 mg/L y 1.5 mg/L), respectivamente está generando problemas a la salud, como el cáncer y la fluorosis esquelética, respectivamente. El objetivo de este trabajo fue determinar la cinética del proceso de adsorción del fluoruro y arsénico en soluciones sintéticas, utilizando gamma alúmina (γ-Al2O3) para establecer si el proceso se desarrolla espontáneamente. Se sintetizó γ-Al2O3 nano-fibrilar, con alta área superficial /g), por precipitación homogénea, y se (352 m2 secó por espray. El nanomaterial adsorbente obtenido se usó para eliminar el fluoruro y el arsénico total de soluciones sintéticas. La morfología de la nano-fibra de γ-Al2O3 mesoporosa se analizó usando microscopía electrónica de transmisión y de barrido. El área superficial se determinó por adsorción-desorción a pH 7 de nitrógeno. Las isotermas de adsorción del proceso de remoción coincidieron con el modelo de Langmuir para ambos elementos. La γ-Al2O3 eliminó hasta 96 % de iones flúor y 92 % de arsénico total a pH 5, mientras que a pH 7 se alcanzó una remoción del 90 % y 94.2 % de fluoruro y arsénico, respectivamente. La cinética de remoción siguió el modelo de seudo-segundo orden, y el parámetro de equilibrio adimensional y la energía libre estándar de Gibbs confirmaron que el proceso se desarrolló espontáneamente. La gamma alúmina nano-fibrilar permitió la remoción natural y espontánea de arsénico y fluoruro presente en las soluciones utilizadas en este estudio.

Abstract In many countries of the world including Mexico, the presence of toxic elements such as arsenic and fluoride on the maximum levels permitted in drinking water (0.01 mg/L and 1.5 mg/L) is causing health problems such as cancer and skeletal fluorosis, respectively. For this reason, the objective of this work was to determine the kinetics of adsorption process of the fluoride and arsenic in synthetic water using gamma alumina (γ-Al2O3) and to determine whether the process develops spontaneously. Nanofiber γ-Al2O3 with high surface area was synthesized by homogeneous precipitation and spray dry method. This adsorbent nanomaterial was used to remove fluoride and total arsenic from synthetic water. Nanofiber morphology of the mesoporous γ-Al2O3 was analyzed by transmission and scanning electron microscopy. The high surface area (352 m2/g) was determined by nitrogen adsorption-desorption. The adsorption isotherms of the removal process concur by the Langmuir model for both toxic elements. γ-Al2O3 removes up to 96 % of fluoride ions and 92 % of total arsenic at pH5, while a removal of 90 % and 94.2 % at pH7 of fluoride and arsenic, respectively, is achieved. The removal kinetics follows the pseudo-second order model, and the dimensionless equilibrium parameter and Gibbs standard free energy confirm that the process is performed spontaneously. The gamma nano-fibrillar alumina is a good material for the natural and spontaneous removal of arsenic and fluoride present in synthetic water used in this study.

Adsorción de un complejo de hierro sobre nanocristales de dióxido de titanio utilizando un residuo piridina / Adsorption of an iron complex on nanocrystals of titanium dioxide using a pyridine residue / Adsorção de um complexo de ferro em nanocristais de dióxido de titânio usando um resíduo de piridina

Resumen Debido a que los fenómenos de adsorción de tinturas sobre óxidos metálicos son de gran importancia en la búsqueda de sistemas de conversión de energía solar, en este trabajo se presenta el comportamiento espectroscópico y electroquímico del complejo [Fe(pytpy2)] (PF6)2 (donde pytpy es 4'-(piridin-4-il)-2,2':6',2"-terpiridina) en solución fluida y anclado sobre una película delgada de nanocristales de dióxido de titanio. La constante de formación del aducto se estimó utilizando el modelo isotérmico de Langmuir y se encontró un valor de 1,03x105 M-1 para dicho complejo. El anclaje del complejo sobre la superficie del óxido metálico semiconductor se debe a la interacción del residuo de piridina con los sitios ácidos de Lewis presentes en la superficie del TiO2. Se observó que las propiedades espectroscópicas y electroquímicas del complejo no se ven modificadas por la adsorción.

Abstract Because the phenomena of adsorption of tinctures on metal oxides are of great importance in the search for solar energy conversion systems, this paper presents the spectroscopic and electrochemical behavior of the complex [Fe(pytpy2)](PF6)2 (where pytpy is 4'-(4-pyridyl)-2,2':6',2''-terpyridine) in a fluid solution and anchored on a thin film of nanocrystals of titanium dioxide. The adduct formation constant was estimated using the Langmuir isothermal model, with a value of 1.03x105 M-1 for the complex. The anchoring of the complex on the surface of the semiconductor metal oxide is due to the interaction of the pyridine residue with the Lewis acid sites presented on the TiO2 surface. Results indicated that the spectroscopic and electrochemical properties of the complex are not modified by the adsorption.

Resumo Os fenômenos de adsorção de tinturas em óxidos metálicos são de grande importância na busca por sistemas de conversão de energia solar, motivo pelo qual neste trabalho o comportamento espectroscópico e eletroquímico do complexo [Fe(pytpy2)] (PF6)2 (onde pytpy é 4'-(piridin-4-il)-2,2':6',2"-terpiridina) em uma solução fluida e ancorada em um filme fino de nanocristais de dióxido de titânio. A constante de formação de aduto foi estimada pelo modelo isotérmico de Langmuir, com valor de 1.03x105 M-1 para o referido complexo. A ancoragem do complexo na superfície do óxido de metal semicondutor é devida à interação do resíduo de piridina com os sítios de ácido de Lewis presentes na superfície do TiO2, observando que as propriedades espectroscópicas e eletroquímicas do complexo não são modificadas pela adsorção.

Adsorption of molybdenum by melanin

BACKGROUND@#Melanin is detectable in various sense organs including the skin in animals. It has been reported that melanin adsorbs toxic elements such as mercury, cadmium, and lead. In this study, we investigated the adsorption of molybdenum, which is widely recognized as a toxic element, by melanin.@*METHODS@#Molybdenum level of the mouse skin was measured by inductively coupled plasma mass spectrometry. The pigmentation level of murine skin was digitalized as the L* value by using a reflectance spectrophotometer. An in vitro adsorption assay was performed to confirm the interaction between molybdenum and melanin.@*RESULTS@#Our analysis of hairless mice with different levels of skin pigmentation showed that the level of molybdenum increased with an increase in the level of skin pigmentation (L* value). Moreover, our analysis by Spearman's correlation coefficient test showed a strong correlation (r = - 0.9441, p < 0.0001) between L* value and molybdenum level. Our cell-free experiment using the Langmuir isotherm provided evidence for the adsorption of molybdenum by melanin. The maximum adsorption capacity of 1 mg of synthetic melanin for molybdenum was 131 μg in theory.@*CONCLUSION@#Our in vivo and in vitro results showed a new aspect of melanin as an adsorbent of molybdenum.

Estudio de la adsorción de 4-nitrofenol desde solución acuosa sobre un carbón activado con heteroátomos nitrogenados en la superficie: aplicación del Modelo de Sips / Adsorption study of 4-nitrophenol from aqueous solution on activated carbon with nitrogen heteroatoms on its surface: application of the Sips Model / Estudo da adsorção de 4-nitrofenol a partir de solução aquosa de carvão ativado com heteroátomos azotados na superfície: aplicação do Modelo de Sips

Resumen Se evaluó la aminación de un carbón activado preoxidado con ácido nítrico en la adsorción de 4-nitrofenol. Se aplicó el modelo de Sips a la adsorción desde solución acuosa, utilizando Sigmoidal Logistic 3 Parameter del programa SigmaPlot 12. Los parámetros obtenidos se compararon con los calculados con el programa Statistica 7 para los modelos de Sips y Langmuir. Se encontró que la modificación realizada sobre el carbón activado incrementó la adsorción de 4-nitrofenol de 2,16 a 2,19 mmolg-1, aumentando, a su vez, la afinidad adsorbente-adsorbato. El parámetro para la energía característica del sistema determinado con el modelo de Langmuir toma un valor de 377,47 L mmol-1 al no considerar la heterogeneidad energética, mientras que a partir del modelo de Sips se presenta un valor de 8,32 (Lmmol-1)1/n. Adicionalmente, se encontró que en la ecuación matemática Sigmoidal Logistic 3 Parameter del programa SigmaPlot el valor de 1/x0 corresponde a la constante KLF del modelo Langmuir-Freundlich, mientras que el valor del parámetro Ks del modelo de Sips es igual a (1/x0)-b. Se concluye que la adsorción de 4-nitrofenol sobre el carbón activado se favorece por el incremento de grupos nitrogenados sobre su superficie.

Abstract The amination of a nitric acid pre oxidized activated carbon in the adsorption of 4-nitrophenol was evaluated. The Sips model application to the aqueous solution adsorption data, using Sigmoidal Logistic 3 Parameter formula, in the SigmaPlot 12 program was applied. The obtained parameters were compared with those calculated with Statistica 7 program for Sips and Langmuir models. It was found that the activated carbon increases the adsorption from 2.16 to 2.19 mmol g-1, showing good adsorbent-adsorbate affinity. The system's characteristic energy parameter calculated with the Langmuir model was 377.47 L mmol-1, when not considering energy heterogeneity, while from the Sips model was 8.32 (L.mmol-1)1/n. Additionally, it was found that in the mathematical equation Sigmoidal Logistic 3 Parameter of the SigmaPlot program, the 1/x0 value corresponds to the Langmuir-Freundlich model constant KLF, while the parameter value KS in the Sips model is equal to (1/x0)-b in this program. It was concluded that the 4-nitrophenol adsorption on activated carbon is favored by the presence of nitrogen groups on their activated carbon surface.

Resumo Foi avaliada a aminação de um carvão ativado preoxidado com ácido nítrico na adsorção do 4-nitrofenol. Foi aplicado o modelo de Sips à adsorção desde solução aquosa usando Logística Sigmoidal 3 do programa Sigmaplot 12. Os parâmetros obtidos foram comparados com os calculados com o programa Statistica 7, para os modelos de Sips e Langmuir. Foi encontrado que a modificação do carvão ativado incrementou a adsorção de 4-nitrofenol de 2,16 até 2,19 mmolg-1, acrescentando a afinidade adsorvente-adsorvato. O parâmetro para a energia característica do sistema calculado com o modelo Langmuir teve um valor de 377,47 Lmmol-1 porque não considerou a heterogeneidade energética, enquanto que no modelo de Sips este parâmetro teve um valor de 8,32 (Lmmol-1)1/n. Além disso, foi encontrado que na equação matemática Sigmoidal Logistic 3 Parameter do programa Sigmaplot 3 o valor de 1/x0 corresponde à constante KLF do modelo Langmuir-Freundlich, enquanto o valor do parâmetro KS do modelo de Sips é igual a (1/x0)-b. Conclui-se que a adsorção do 4-nitrofenol sobre carvão ativado é favorecida pela presença de grupos nitrogenado na superfície destes.

Potassium adsorption in soil cultivated with sugarcane

ABSTRACT Vinasse is a byproduct of the process of distillation of sugarcane juice for the manufacture of sugar and alcohol. Because it is rich in nutrients, mainly potassium (K), is used as fertilizer and applied via fertigation, without concerning for the fate of this compound in the soil. Thus, the objective of the study was to evaluate the interactions of the potassium ion (K+), applied via vinasse in a soil representative of the sugarcane zone of the State of Pernambuco using adsorption isotherms. The methodology was based on physical, chemical and soil mineralogical characterization, as well as equilibrium batch tests, where the experimental curves were fitted by Langmuir and Freundlich isotherm models. The results allowed to infer that the Freundlich model showed better fit of the curve in both forms: linear and non-linear (direct fit); the non-linear model was selected due to the values ​​of coefficient of determination (R²). The interaction between potassium and soil occurred mainly with organic matter and the presence of soil kaolinite, because they showed negative ions on the external surface, thereby promoting potassium adsorption. Soil potassium adsorption capacity was higher for the first layer (0-20 cm) and decreased along the depth profile.

Adsorption and availability of phosphorus in response to humic acid rates in soils limed with CaCO3 or MgCO3 / Adsorção e disponibilidade de fósforo em resposta a doses de ácido húmico em solos corrigidos por CaCO3 ou MgCO3

ABSTRACT Humic acid (HA) may reduce adsorption and increase soil P availability, however, the magnitude of this effect is different when Ca2+ prevails over Mg2+ in limed soils. The objective of this study was to evaluate the effects of HA rates and carbonate sources on the adsorption, phosphate maximum buffering capacity (PMBC), and P availability in two contrasting soils. Oxisol and Entisol samples were firstly incubated with the following HA rates: 0, 20, 50, 100, 200 and 400 mg kg-1, combined with CaCO3 or MgCO3, to evaluate P adsorption. In sequence, soil samples were newly incubated with P (400 mg kg-1) to evaluate P availability. The least P adsorption was found when 296 mg kg-1 of HA was added to Oxisol. Applying HA rates decreased maximum adsorption capacity, increased P binding energy to soil colloids and did not alter PMBC of Entisol. Available P contents in Oxisol increased with HA rates, but it did not change in Entisol. Choosing the right HA rate can decrease PMBC up to 40% and increase the Oxisol P availability by 17%. Application of MgCO3 instead of CaCO3 decreased P adsorption in both soils. Thus, a positive correlation between Ca2+ content and PMBC was verified. Optimum rate of HA and the preponderance of Mg2+ instead of Ca2+ in soil volume fertilized with P are effective practices to reduce adsorption and increase P availability, especially in clayey Oxisol.

RESUMO O ácido húmico (AH) pode reduzir a adsorção e aumentar a disponibilidade de P nos solos, entretanto, a magnitude desse efeito é diferente quando o Ca2+ prevalece sobre Mg2+ em solos com acidez corrigida. Objetivou-se avaliar os efeitos de doses de AH e fontes de carbonato na adsorção, fator capacidade de P máximo (FCPm) e disponibilidade de P em solos contrastantes. Amostras de Latossolo e Gleissolo foram primeiramente incubadas com as seguintes doses de AH: 0, 20, 50, 100, 200 e 400 mg kg-1, combinadas com CaCO3 ou MgCO3, para avaliar a adsorção de P. Em sequência, as amostras de solo foram novamente incubadas com P (400 mg kg-1), para determinar a disponibilidade de P. A aplicação de doses de AH reduziu a capacidade máxima de adsorção, aumentou a energia de ligação do P e não alterou a FCPm do Gleissolo. O teor de P disponível aumentou com o acréscimo das doses de AH no Latossolo, contudo, não foram alterados no Gleissolo. A escolha correta da dose de AH reduziu a FCPm em até 40% e aumentou a disponibilidade de P no Latossolo em 17%. A aplicação de MgCO3 em vez do CaCO3 reduziu a adsorção de P em ambos os solos. Assim, houve correlação positiva entre o teor de Ca2+ e a FCPm. A dose ótima de AH e a predominância de Mg2+ sobre Ca2+ no volume de solo adubado com P são práticas efetivas para reduzir a adsorção e aumentar a disponibilidade de P, especialmente, no Latossolo argiloso.

Enzymes immobilized in Langmuir-Blodgett films: Why determining the surface properties in Langmuir monolayer is important?

ABSTRACT In this review we discuss about the immobilization of enzymes in Langmuir-Blodgett films in order to determine the catalytic properties of these biomacromolecules when adsorbed on solid supports. Usually, the conformation of enzymes depends on the environmental conditions imposed to them, including the chemical composition of the matrix, and the morphology and thickness of the film. In this review, we show an outline of manuscripts that report the immobilization of enzymes as LB films since the 1980's, and also some examples of how the surface properties of the floating monolayer prepared previously to the transfer to the solid support are important to determine the efficiency of the resulting device.

Capacidad de adsorción de plomo con intercambiadores catiónicos de carbón xantado / Adsorption capacity of lead with cationics exchangers of xanted coal

En este estudio, se describe la adsorción de plomo (Pb2+) en soluciones acuosas, a partir de carbón modificado, mediante tratamiento con CS2 y NaOH, empleando una relación 16,6:1 NaOH/Carbón p/p y 4,08:1 CS2/carbón p/p. Se realizaron pruebas de pH, cinéticas e isotermas de adsorción, para evaluar la capacidad de adsorción del carbón xantado y carbón no xantado. Los grupos azufre en el carbón xantado fueron identificados por espectroscopia infrarroja de reflectancia difusa (FTIR) y comparados con los espectros del carbón no xantado. Los resultados muestran que la mejor remoción de plomo en la solución con una concentración de 100mg de Pb2+/L y dosis de 50mg de adsorbente/10mL, respectivamente, fue a un valor de pH 5,0, logrando un porcentaje de adsorción de 98%. Los estudios cinéticos indican que el proceso de adsorción puede alcanzar el equilibrio alrededor de 120min, siguiendo una cinética de pseudo-segundo orden, para ambos materiales. El estudio de las isotermas indica que el carbón se ajusta mejor a una isoterma de tipo Langmuir y cuando se somete a la xantación, se ajusta a una isoterma de tipo Freundlich.

This study describes the adsorption of lead (Pb2+) in aqueous solutions of modified coal by treatment with CS2 and NaOH, using a ratio of 16,6:1 NaOH/coal (w/w) and 4,08 CS2/coal (w/w). Different tests such as acidity, kinetic and adsorption isotherms were carried out in order to assess the adsorption capacity of xanted and non-xanted coal. The sulfur groups presented in the xanted coal were identified by infrared spectroscopy(FTIR) and they were compared with non-xanted coal spectrum. The results show that the best lead removal in the solution (with a concentration of 100mg Pb2+/L and 50mg of adsorbent) was obtained at pH 5.0 for both coal (xanted and non-xanted) with an adsorption percentage of 98%. The kinetic studies indicate that the adsorption process can reach the equilibrium in about 120 minutes, following a pseudo-second order kinetics for both materials. The isotherms study indicates that the coal fits best to a Langmuir-type isotherm, however when the coal is xanted, it fits best to a Freundlich-type isotherm.

ADSORCIÓN DE PLOMO (II) EN SOLUCIÓN ACUOSA CON TALLOS Y HOJAS DE Eichhornia crassipes / ADSORPTION OF LEAD (II) WITH STEMS AND LEAVES OF Eichhornia crassipes IN AQUEOUS SOLUTION

La presencia de metales pesados, como el plomo (Pb+2), en los cuerpos de agua genera alteraciones sobre la calidad ambiental y la salud pública, debido a su solubilidad y su capacidad de acumulación en la cadena trófica, problemática que se puede incrementar por la acumulación de Eichhornia crassipes, una maleza acuática con alta capacidad invasora, cuya presencia en los ecosistemas acuáticos favorece los procesos de eutrofización y crecimiento de microorganismos patógenos, vectores de enfermedades. Como alternativa para la eliminación de metales pesados y el aprovechamiento de tallos TEC y hojas HEC de E. crassipes, se evaluó la capacidad de adsorción y de eficiencia de remoción de Pb+2 en solución acuosa, de dicha biomasa. Inicialmente, se realizaron ensayos batch, para analizar la influencia de la dosis de adsorbente, tiempo de contacto y pH de la solución. Como método de disposición final, se analizó la calcinación, a temperaturas de 700 y 800°C. Los datos experimentales de equilibrio fueron correlacionados, utilizando los modelos de Langmuir y Freundlich. El modelo que mejor se ajustó fue el de Langmuir, con R² = 0,9816 TEC y R² = 0,9854 HEC, lográndose una máxima capacidad de adsorción de 172,41mg/g TEC y 131,58mg/g HEC, con 0,2g de biomasa/200mL, pH 5,5 y 3h de contacto. En todos los ensayos, se lograron remociones de Pb+2 superiores al 97%. Los ensayos de calcinación indican que, a temperaturas ≥800°C, es posible estabilizar la biomasa residual, impidiendo que los cationes metálicos removidos sean liberados de la matriz biológica, por efectos de soluciones lixiviantes de bajo pH.

The presence of heavy metals such as lead (Pb+2) in water bodies causes alterations in environmental quality and public health due to their solubility and capacity of accumulation in the food chain. Problems that can be increased by the accumulation of Eichhornia crassipes an aquatic weed with high invasive capacity whose presence in the aquatic ecosystems favors the processes of eutrophication and growth of pathogenic microorganisms vectors of diseases. As an alternative for the removal of heavy metals and the use of TEC stems and HEC leaves of E. crassipes, the adsorption capacity and removal efficiency of Pb+2 in aqueous solution of this biomass were evaluated. Initially batch tests were performed to analyze the influence of the adsorbent dose, contact time and solution pH. As final disposal method, the calcination was analyzed at temperatures of 700 and 800°C. The equilibrium experimental data were correlated using the Langmuir and Freundlich models. The best fit model was the Langmuir model with R²=0.9816 TEC and R²=0.9854 HEC, achieving a maximum adsorption capacity of 172.41mg/g TEC and 131.58mg/g HEC with 0.2 g Of biomass/200mL, pH 5.5 and 3h of contact. Pb+2 removals above 97% were achieved in all tests. Calcination tests indicate that at temperatures ≥800°C it is possible to stabilize the residual biomass by preventing the removed metal cations from being released from the biological matrix by the effects of low pH leaching solutions.

Panus tigrinus as a potential biomass source for Reactive Blue decolorization: isotherm and kinetic study

Background: Textile and dye industries pose a serious threat to the environment. Conventional methods used for dye treatment are generally not always effective and environmentally friendly. This drove attention of scores of researchers to investigate alternative methods for the biodegradation of dyes using fungal strains. In this work, white-rot fungus (Panus tigrinus) was used as a biosorbent for the decolorization of Reactive Blue 19. The process parameters that were varied were initial concentration (50­150 mg/L), contact time (30­90 min), and pH (2­6). In addition, to gain important data for the evaluation of a sorption process, the equilibrium and kinetics of the process were determined. Results: White-rot fungus showed great potential in decolorizing Azo dyes. The strain showed the maximum decolorization of 83.18% at pH 2, a contact time of 90 min, and an initial concentration of 50 mg/L. The Langmuir isotherm described the uptake of the Reactive Blue 19 dye better than the Freundlich isotherm. Analysis of the kinetic data showed that the dye uptake process followed the pseudo second-order rate expression. Conclusion: The biosorption process provided vital information on the process parameters required to obtain the optimum level of dye removal. The isotherm study indicated the homogeneous distribution of active sites on the biomass surface, and the kinetic study suggested that chemisorption is the rate-limiting step that controlled the biosorption process. According to the obtained results, P. tigrinus biomass can be used effectively to decolorize textile dyes and tackle the pollution problems in the environment.

Evaluation of surface properties of erythrocyte membranes in liver diseases.

Background: The physicochemical properties of Red Blood Cell membranes (RBC) are altered in liver diseases. Langmuir monolayers offer an excellent model system to study biological membrane surface properties. The aim of this study was to evaluate surface properties of erythrocyte membranes in liver diseases. Methods: Sixty-one patients with various liver diseases and fifteen controls were enrolled. Surface properties of RBC membrane were evaluated using Langmuir monolayers. Surface pressure area isotherms were recorded at body temperature using RBC membrane lipid extract. Student‟s t-test and Analysis of variance tests were performed. Results: Mean maximum surface pressure and hysteresis area were significantly higher in cirrhotic and non-cirrhotic liver disease groups compared to controls. Within cirrhotics, mean maximum surface pressure and lift off area was significantly lower in the Child C group as compared to the Child A, B and A-B groups. The mean hysteresis area was significantly lower in the Child C group as compared to the Child B and A-B groups. Conclusion: The results of our study confirmed high rigidity of RBC membrane in mild and moderate liver cirrhosis and high fluidity in severe liver cirrhosis. This study may pave the way to the development of a surface activity based biophysical tool for therapeutic implication in liver diseases.

Adsorción de Cr(VI) por Cocos nucífera L. en residuales de Fibrocemento en Santiago de Cuba / Cr(VI) adsorption by Cocos nucífera L. in wastewater of fibrocement from Santiago de Cuba

La adsorción y/o formación de complejos de metales pesados basados en la actividad química de la biomasa, es el proceso conocido como biosorción y es la base de una nueva tecnología para su remoción en efluentes industriales y su posterior recuperación. En esta tecnología se pueden utilizar diferentes tipos de biomasas tales como: algas, microorganismos y sub-productos agrícolas. Este trabajo estudió la adsorción de Cr(VI) utilizando la cáscara del fruto de la planta Cocos nucífera L. como biomasa orgánica. Los valores óptimos de adsorción de Cr(VI) son: pH de 3 unidades; tamaño de partícula menor que 0,074 mm; dosis de adsorbente de 5 g.dm-3 y tiempo contacto de 1 hora. A valores bajos de concentración del metal (1,0; 1,5 y 1,84 mg.dm-3) se obtuvo porcentaje de remoción superiores a 90, sin embargo a altos valores de concentración (2,5 y 3 mg.dm-3), se obtienen valores inferiores al 90 %. El proceso pudo ser estudiado a través de los modelos de Langmuir y de Freundlich, ya que el coeficiente de correlación para ambos modelos fue de 0,994 y 0,991 respectivamente. Se logra remover los iones Cr(VI) a valores de pH de 3 y 7 unidades en una matriz real, alcanzando valores de remoción de 96,85 % y 93,71 % respectivamente.

Adsorption and/or formation of complexes of heavy metals based on the chemical activity of the biomass, it is the process known as biosorption and it is the base of a new technology for its removal in industrials effluent and its posterior recuperation. In this technology, different kinds of biomasses can be utilized such as: algae, microorganisms and agricultural subproducts. In this work, the adsorption of Cr(VI) was studied utilizing the nutshell of the fruit of the plant Cocos nucífera L as organic biomass. The optimal values of adsorption of Cr(VI) are: pH of 3 units, size of particle smaller than 0.074 mm, doses of adsorbent of 5 g.dm-3 and contact time of 1 hour. At low values of concentration of the metal (1.0, 1,5 and 1.84 mg.dm-3) percentage of removal superior to 90% were obtained, however, at high values of concentration (2.5 and 3 mg.dm-3) values inferior to 90 % are obtained. The process can be studied by the models of both, Langmuir and of Freundlich, because the , coefficient of correlation for these two models was 0.994 and 0.991 respectively. The ions Cr(VI) can be removed at values of 3 and 7 units in a real matrix, reaching removal values of 96.85% and 93.71% respectively.

Preparation, properties and anti-tumor effect of the self-assemblies of a phosphoryl N-tetradecanoyl gemcitabine derivative / 国际药学研究杂志

Objective: To prepare the self-assemblies of a phosphoryl N-tetradecanoyl gemcitabine (CPTG) derivative and evaluate the properties and anti-tumor effect. Methods: CPTG derivative was synthesized. The prodrug membrane was investigated using a Langmuir trough. The self-assembly was prepared using the injection method. The morphology of self-assemblies was observed by a transmission electron microscope. The particle distribution was measured by a dynamic light scattering instrument. The pharmacodynamic effect was evaluated on HepG2 cells and tumor-bearing mice. Results: The prodrug was synthesized with gemcitabine as the raw material. The surface pressure-molecular area (π-a) curves at the air/water interface indicated that the prodrug was amphiphilic and formed the stable monolayer. The self-assemblies formed the vesicles with the mean size of 93.52 nm and the Zeta potential of -31 mV. The inhibitory effects of self-assemblies were significantly higher than those of gemcitabine on the models of HepG2 cells and the tumor-bearing mice. Conclusion: The self-assemblies of the amphiphilic prodrug of gemcitabine might be a promising novel nanomedicine for targeted therapy of liver cancer.

Low cost single-step purification of endoglucanase from Aspergillus fumigatus ABK-9.

Low cost agro-waste was used as adsorption support for single-step purification of endoglucanase from the culture filtrate of A. fumigatus ABK-9. Among various agro-waste substrates, 1% NaOH pretreated rice bran was proved to be the best for adsorbing about 74.8 and 71.1% of endoglucanase at 4 °C and 10 °C respectively. Langmuir type adsorption isotherm at 4 °C showed maximum adsorption of enzyme at pH 5.0, which was in the range of optimum pH of the enzyme. The rice bran column bound enzyme was maximally eluted by a mixture of acetate buffer (0.05 M, pH 5.5) and ethanol (40%, v/v) at a ratio of 3:2 and a flow rate of 1 mL/min. A 5.52-fold purification of the enzyme was achieved from culture supernatant. The specific activity and recovery yield after purification were 294.0 U/mg and 40.15%, respectively, which were comparable with other contemporary protocols. The homogeneity of the enzyme was tested through sodium dodecyl sulphate polyacrylamide gel electrophoresis and a single band of 56.3 kDa was observed. Zymogram analysis finally confirmed the occurrence of endoglucanase in the single band.

Study on Thermodynamics and Adsorption kinetics of Purified endoglucanase (CMCase) from Penicillium notatum NCIM NO-923 produced under mixed solid-state fermentation of waste cabbage and Bagasse

In the current study, one thermostable endoglucanase was purified from Penicillium notatum NCIM NO-923 through mixed solid state fermentation of waste cabbage and bagasse. The molecular weight of the purified enzyme was 55kDa as determined by SDS polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme had low activation energy (Ea) of 36.39KJ mol-1 for carboxymethyl cellulose hydrolysis and the enthalpy and entropy for irreversible inactivation was 87 kJ mol −1 and 59.3 J mol −1 K−1 respectively. The enzyme was quite thermostable with a Tm value of 62.2˚C. The pKa1 and pKa2 of ionizable groups of the active sites were 2.5 and 5.3 respectively. Apparent Km, Vmax and Kcat of the enzyme were found to be 5.2 mg mL-1, 80 U/gds and 322.4 sec-1 respectively. The enzyme showed about 1.4 fold increased activity in presence of 10mM MgSO4. Adsorption of endoglucanase on Avicel at wide pH range was studied at different temperatures. Langmuir type adsorption isotherm at 10˚C showed maximum adsorption strength of enzyme at pH 3.0, which was in a range of optimum pH of the enzyme.

Remoción de crooo hexavalente de aguas contamindas usando quitosano obtenido dde exoesqueleto de camarón / Removalof hexavaalent chromium from contaminated water sing chitosan oobtained from shrimp exoskeleton / Remoção de cromo hexavalente de aguas contaminadas usando quitosaa obtido de exooesqueleto de camarão

El exoesqueleto de camarón desechado por la industria puede ser aprovechado para la obtención de quitina y quitosano con la utilización de reactivos comerciales de muy bajo costo. El quitosano es un biopolímero que tiene diversos usos, entre ellos, la remoción de metales pesados a partir de aguas residuales. En este estudio se utilizó quitosano para la remoción de cromo hexavalente a partir de muestras de aguas residuales del proceso de galvanizado (cromado) de una industria de Cartagena. La remoción de cromo se realizó por un proceso discontinuo, a un pH óptimo encontrado en este estudio de 2.0 y una temperatura de 26 °C. La cinética de adsorción fue estudiada mediante el uso de la isoterma de Langmuir, siendo la capacidad máxima de adsorción (Qmax) de 200 mg/g. La remoción de cromo hexavalente a partir de las muestras de aguas residuales fue del 99.98 %.

The exoskeleton of shrimp discarded by the industry, can be used for the production of chitin and chitosan with the use of very low cost commercial reagents. Chitosan is a biopolymer that has many uses, including heavy metals removal from wastewater. In this study, chitosan was used to remove hexavalent chromium from wastewater samples from the galvanizing process (chrome) of an industry in the city of Cartagena. The chromium removal was performed by a batch process at an optimum pH found in this study of 2.0 and a temperature of 26 °C. The adsorption kinetics was studied by using the Langmuir isotherm, being the maximum adsorption capacity (Qmax.) of 200 mg/g. The removal of hexavalent chromium from wastewater samples was 99.98 %.

O exoesqueleto de camarão desperdiçado pela indústria pode ser aproveitado para a obtenção de quitina e quitosana usando reagentes comerciais de baixo custo. A quitosana é um biopolimero que tem diversos usos como a remoção de metais pesados de aguas residuais. Neste estudo se usou quitosana para a remoção de cromo hexavalente de amostras de aguas residuais do processo de galvanizado (cromado) de uma indústria da cidade de Cartagena (Colômbia). A remoção do cromo se realizou através de um processo continuo em um pH de 2.0 como condição ótima encontrada durante a realização deste estudo e uma temperatura de 26 °C. A cinética de adsorção foi estudada através do uso da isoterma de Langmuir, sendo a capacidade máxima de adsorção (Qmax) de 200 mg/g. A remoção de cromo hexavalente a partir das amostras residuais foi de 99.98 %.

Equilibrium isotherm studies of methylene blue from aqueous solution unto activated carbon prepared form strychnos potatorum seed.

Methylene blue adsorption from aqueous solution onto activated carbon prepared from strychnos potatorum seed was investigated under various experimental conditions. Batch mode experiments and equilibrium isotherm studies were conducted to assess the potential of the above activated carbon for the removal of Methylene blue from aqueous solution by varying the following three parameters: initial concentration of Methylene blue dye solution, adsorbent dose on the uptake of dye from the solution, and pH. The equilibrium data obtained were fitted to Langmuir and Freundlich isotherm models.

"A wild and wondrous ride": CDC field epidemiologists in the east Pakistan smallpox and cholera epidemics of 1958 / "Uma louca e maravilhosa jornada": epidemiologistas de campo do CDC nas epidemias de varíola e cólera do Paquistão Oriental em 1958

In mid-April of 1958 the Government of Pakistan summoned the press to announce a grave need for international aid to cope with smallpox and cholera epidemics in East Pakistan. In response, and with the backing of the US State Department, Dr. Alexander D. Langmuir, chief epidemiologist of the CDC, led a team of epidemiologists to assist authorities in Dacca strengthen their immunization programs. Langmuir's superiors hoped for a Cold War advantage, but he saw an opportunity for trainees in the Epidemic Intelligence Service to learn about public health in a developing country. Langmuir later described the episode as a "wild and wondrous ride," but it had been more like a nightmare: the East Pakistan health department had collapsed; a popular movement had taken over vaccination and squandered vaccine supplies; hostile journalists had questioned the Americans' deeper motives; and a professional rivalry opened between the Americans and a British epidemiologist named Aidan Cockburn. By the time the epidemic subsided in July 1958, 30 million Bengalis had been vaccinated for smallpox but another 20,000 had succumbed to the disease. This episode was CDC's first sustained foreign intervention, a precursor to its extensive role in the 1970s helping WHO eradicate smallpox from Bangladesh.

Em meados de abril de 1958, o Governo do Paquistão convocou a imprensa para anunciar a urgente necessidade de auxílio internacional para lidar com epidemias de varíola e cólera no Paquistão Oriental. Em resposta, e com o apoio do Departamento de Estado dos Estados Unidos, Dr. Alexander D. Langmuir, chefe de epidemiologia do CDC em Atlanta, liderou um time de epidemiologistas para auxiliar as autoridades em Dacca a reforçar seus programas de imunização. Os superiores de Langmuir ansiavam por demonstrações de capacidade dos EUA na Guerra Fria, mas ele vislumbrou uma chance para o Serviço de Inteligência Epidemiológica aprender sobre saúde pública em países em desenvolvimento. Langmuir descreveu o episódio como uma "jornada louca e maravilhosa", porém pareceu mais um pesadelo: o departamento de saúde do Paquistão Oriental entrou em colapso; um movimento popular assumiu a vacinação e desperdiçou suprimentos de vacinas; jornalistas hostis questionaram as motivações ocultas dos americanos; e iniciou-se uma rivalidade profissional entre americanos e o epidemiologista britânico Aidan Cockburn. No final da epidemia, em julho de 1958, tinham sido vacinados trinta milhões de bengalis contra varíola, mas outros vinte mil sucumbiram. Esse episódio foi a primeira intervenção sistemática do CDC no exterior.