Effect of sulfonated block copolymer on the equilibrium and thermal properties of sulfonated fluoroblock copolymer blend membrane / Efecto del copolímero en bloque sulfonado sobre las propiedades térmicas y de equilibrio de una membrana sulfonada mezclada con un fluoropolímero en bloque

Polymeric membrane technologies demand the synthesis of new polymers to enhance their equilibrium, thermal, and transport properties. Therefore, the focus of this investigation was the evaluation of the equilibrium and thermal properties of a sulfonated fluoroblock copolymer blend membrane composed of sulfonated poly(styre-ne-isobutylene-styrene) (SIBS SO3H) and a novel sulfonated fluoroblock copolymer composed of poly(4-fluo-rostyrene) (P4FS), poly(styrene) (PS) and poly(isobutylene) (PIB). The fluoroblock copolymer was synthesized using Atom Transfer Radical Polymerization (ATRP) and cationic polymerization. First, the molecular weight and the thermal stability of the block copolymer were determined using Gel Permeation Chromatography (GPC) and Thermogravimetric Analysis (TGA). Second, the chemical composition was monitored utilizing Fourier Transform Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The molecular weight of P4FS-b-PS was Mn ~ 36,100; this value increased 8% after the cationic polymerization. The equilibrium properties of the membrane were evaluated using the water uptake and Ion-Exchange Capacity. The degradation behavior and the thermal transitions were determined using TGA and Differential Scanning Calorimetry (DSC), respectively. This newly membrane exhibited water uptake higher than 608% related to the improvement of 36% in the ion-exchange capacity and the increment of 25.31% and 25.24% in the energy required to produce the thermal transitions induced by the addition of the sulfonated fluoroblock copolymer.

La tecnología de membranas poliméricas requiere de la síntesis de nuevos polímeros que mejoren sus propiedades de equilibrio, térmicas y de transporte. Esta investigación tuvo como objetivo determinar las pro-piedades de equilibrio y térmicas de una membrana compuesta de poli(estireno-isobutileno-estireno) sulfonado (SIBS SO3H) y un fluoropolímero en bloque sulfonado compuesto de poli(4-fluorostireno) (P4FS), poli(estireno) (PS) y poli(isobutileno) (PIB). El fluoropolímero en bloque se sintetizó utilizando la técnica de polimerización radical por transferencia atómica (ATRP por sus siglas en inglés) y polimerización catiónica. El peso molecular y la estabilidad térmica del fluoropolímero en bloque fueron determinadas por medio de Cromatografía de Permeación en Gel (GPC) y un análisis termogravimétrico (TGA). La composición química se monitorizó utilizando espectroscopía infrarroja por transformada de Fourier (FTIR) y espectroscopía de Resonancia Magnética Nuclear (RMN). El peso molecular de P4FS-b-PS fue Mn ~ 36,100; este valor aumentó un 8% después de la polimerización catiónica. Las propiedades de equilibrio de la membrana fueron evaluadas por medio de la absorción de agua y la capacidad de intercambio iónico. El comportamiento de degradación y las transiciones térmicas se determinaron utilizando TGA y Calorimetría Diferencial de Barrido (DSC). Esta nueva membrana exhibió una absorción de agua mayor del 608% relacionada con la mejora del 36% en la capacidad de intercambio iónico y el incremento en 25.31% y 25.24% en la energía requerida para producir las transiciones termales inducidas por la adición del fluoropolímero sulfonado en bloque.

Cholestyramine Use for Rapid Reversion to Euthyroid States in Patients with Thyrotoxicosis

Cholestyramine (CS) is an ion exchange resin, which binds to iodothyronines and would lower serum thyroid hormone level. The use of CS added to conventional antithyroid drugs to control thyrotoxicosis has been applied since 1980's, and several studies indicate that using CS in combination with methimazole (MZ) produces a more rapid decline in serum thyroid hormones than with only MZ treatment. Our recent retrospective review of five patients taking high dose MZ and CS, compared to age-, gender-, initial free thyroxine (T4) level-, and MZ dose-matched 12 patients with MZ use only, showed more rapid decline of both free T4 and triiodothyronine levels without more adverse events. CS could be safely applicable short-term adjunctive therapy when first-line antithyroid medications are not enough to adequately control severe thyrotoxicosis or side effects of antithyroid drug would be of great concern.

Isotope effects of neodymium in different ligands exchange systems studied by ion exchange displacement chromatography

The isotope effects of neodymium in Nd-glycolate ligand exchange system were studied by using ion exchange chromatography. The separation coefficients of neodymium isotopes, epsilon's, were calculated from the observed isotopic ratios at the front and rear boundaries of the neodymium adsorption band. The values of separation coefficients of neodymium isotopes, epsilon's, for the Nd-glycolate ligand exchange system were compared with those of Nd-malate and Nd-citrate, which indicated that the isotope effects of neodymium as studied by the three ligands takes the following direction Malate > Citrate > Glycolate. This order agrees with the number of available sites for complexation of each ligand. The values of the plate height, HETP of Nd in Nd-ligand exchange systems were also calculated

A Case of Red Blood Cell Exchange Transfusion in a Patient with Hemoglobin S/beta-Thalassemia / 대한수혈학회지

Sickle cell disease and beta-thalassemia are caused by abnormal hemoglobin (Hb) derived from mutation of the HBB gene encoding beta-globin. Compound heterozygous status for both mutations results in Hb S/beta-thalassemia (sickle-beta-thalassemia). Vaso-occlusive phenomena and hemolysis are the clinical hallmarks and major causes of mortality. Due to the limited availability of hematopoietic stem cell transplantation with or without gene therapy, red blood cell (RBC) exchange transfusion is the first-line adjunctive therapy. Here we report on a successful reduction of Hb S level in a Tunisian male sickle-beta-thalassemia patient by RBC exchange transfusion for primary prophylactic transfusion therapy before flying to his country. Results of both Ion exchange high-performance liquid chromatography and HBB gene mutation analysis indicated sickle-beta-thalassemia. Pre-erythrocytapheresis Hb S level was 80.6% of total Hb. Two volumes of RBC exchange were performed using automated erythrocytapheresis with the COBE Spectra Apheresis System (Version 7.0, Caridian BCT, CO, USA). Post-erythrocytapheresis Hb S level was 23.4% of total Hb and hematocrit level was 32.6%, both of which met the target end points. This is the first case report in Korea on successful RBC exchange transfusion in a patient with sickle-beta-thalassemia for rapid reduction of pathologic RBCs with Hb S.

A Case of Red Blood Cell Exchange Transfusion in a Patient with Hemoglobin S/beta-Thalassemia / 대한수혈학회지

Sickle cell disease and beta-thalassemia are caused by abnormal hemoglobin (Hb) derived from mutation of the HBB gene encoding beta-globin. Compound heterozygous status for both mutations results in Hb S/beta-thalassemia (sickle-beta-thalassemia). Vaso-occlusive phenomena and hemolysis are the clinical hallmarks and major causes of mortality. Due to the limited availability of hematopoietic stem cell transplantation with or without gene therapy, red blood cell (RBC) exchange transfusion is the first-line adjunctive therapy. Here we report on a successful reduction of Hb S level in a Tunisian male sickle-beta-thalassemia patient by RBC exchange transfusion for primary prophylactic transfusion therapy before flying to his country. Results of both Ion exchange high-performance liquid chromatography and HBB gene mutation analysis indicated sickle-beta-thalassemia. Pre-erythrocytapheresis Hb S level was 80.6% of total Hb. Two volumes of RBC exchange were performed using automated erythrocytapheresis with the COBE Spectra Apheresis System (Version 7.0, Caridian BCT, CO, USA). Post-erythrocytapheresis Hb S level was 23.4% of total Hb and hematocrit level was 32.6%, both of which met the target end points. This is the first case report in Korea on successful RBC exchange transfusion in a patient with sickle-beta-thalassemia for rapid reduction of pathologic RBCs with Hb S.

Enzymatic and toxinological activities of Hypnale hypnale (hump-nosed pit viper) venom and its fractionation by ion exchange high performance liquid chromatography

Hypnale hypnale (hump-nosed pit viper) has been recently identified as one of the medically important venomous snakes in Sri Lanka and on the southwestern coast of India. The characterization of its venom is essential for understanding the pathophysiology of envenomation and for optimizing its management. In the present study, the biological properties of Hypnale hypnale venom and venom fractions obtained using Resource Q ion exchange chromatography were determined. The venom exhibited toxic activities typical of pit viper venom, comparable to that of its sister taxon, the Malayan pit viper (Calloselasma rhodostoma). Particularly noteworthy were its high activities of thrombin-like enzyme, proteases, phospholipase A2, L-amino acid oxidase and hyaluronidase. The thrombin-like enzyme was mainly acidic and distributed over several chromatography fractions, indicating its existence in multiple isoforms. The hemorrhagic and necrotic activities of the venom were likely associated with the proteolytic enzyme found mainly in the basic fraction. Phospholipase A2 and phosphomonoesterase exist in both acidic and basic isoforms, while L-amino acid oxidase and hyaluronidase are highly acidic. The venom clotting activity on fibrinogens showed distinct species specificity in the following increasing order for clotting time: bovine < rabbit < goat < human < horse < < dog, and was comparable to that of C. rhodostoma venom. Its clot formation on human fibrinogen is gradual and prolonged, a phenomenon suggestive of consumptive coagulopathy as a complication observed clinically. At an intramuscular sublethal dose, the venom did not cause acute kidney injury in a rodent model, contrary to the positive control group treated with Daboia russelii venom. Nephrotoxicity may result from higher venom doses in the context of coagulopathy, as a complication provoked by venom hematoxicity.(AU)

Nitrate removal from drinking water by point of use ion exchange

A laboratory study was conducted to investigate the ability of a special type of strongly basic resin MP500WS for the removal of nitrate from different waters. Two different types of Point-of-Use [POU] devices containing an identical resin were used. MP500WS known as macro porous was used in POU devices for removal of high concentrations of nitrate and sulfate ions from water. Sulfate and chloride ions are considered the most important interferences in the treatment process of nitrate by most anion exchange resins. The results obtained by treatment of water samples having different ranges of nitrate [20 to 150 mg/L], sulfate [50, 100 and 800 mg/L] and chloride [50 and 500 mg/L] have shown that the method was suitable for delivering water with NO[3] concentrations in less than its maximum contaminant level [MCL=45 mg/L] as long as the initial NO[3], SO[4] and CI concentration has remained in less than 150, 100 and 500 mg/L, respectively. For this purpose, POU systems that utilize a suitable tested resin may be considered as an economical and effective alternative to conventional systems. This study shows this strategy very effective for nitrate reduction to acceptable levels when macro porous type strongly basic resin is used as the resin

Investigation of clinoptilolite natural zeolite regeneration by air stripping followed by ion exchange for removal of ammonium from aqueous solutions

The purpose of this study was to regenerate clinoptilolite natural zeolite by air stripping followed by removal of ammonium from aqueous solutions. The research was carried out in continuous system. The characteristics of graded clinoptilolite from Semnan [one of the central provinces in Iran] mines were determined and then regeneration tests were done by contacting of 1 N NaC1 solution with given weights of ammonium saturated zeolite. Then the brine of column was transferred to the air stripping column for regeneration. The pH of brine solution before entrance to a stripping column was increased to 11. Air stripped ammonia from the brine was converted to the ammonium ion by using acid scrubber. The outlet effluent from stripping column was collected for reuse. The results showed that the cation exchange capacities were 17.31 to 18.38mg NH[4+]/g of zeolite weight. Regeneration efficiency of zeolite by NaC1 solution and air stripping was in the range of 92%-97% under various operational conditions. However, the efficiency of acid absorption of released ammonia in stripping process was 55% with a major rejection of the surplus ammonia to the atmosphere. It could be concluded that the method studied may be considered as an advanced and supplementary process for treating effluents of aqueous solution and fishponds in existing treatment plants

Hydrogeochemistry of thirumanimuttar basin: an indication of weathering and anthropogenic impact

A total of 148 groundwater samples were collected from bore wells from Thirumanimuttar sub-basin for two seasons to identify major geochemical process activated to alter groundwater chemistry. The study revealed relationships with the lithology and anthropogenig process. Groundwater in the region was domnated by Na- Ca - Mg and Cl and HCO[3] types. The [Ca + Mg] Versus TZ[+] plot for both seasons reveals higher Ca and Mg due to leaching due to silicate mineral weathering from aquifer matrix of the study area. The plot for [Na+K] versus TZ[+] indicates weathering process of both alkali and alkali earth from feldspars along with additional sources like contribution from alkali/saline soil and residence time. Saturation index of silicate, carbonate and fluoride minerals indicates oversaturation and equilibrium state and sulfate minerals were at undersaturated state during both the seasons. Lithology and anthropogenic activity plays a significant role in controlling groundwater chemistry of the study area

beast available technology for small electroplating plants applying analytical hierarchy process

In this study analytical hierarchy process approach which uses expert's knowledge, was applied for selection of the best wastewater treatment alternative for electroplating workshops, located in Tehran province, Iran. This method can be applied for complicated multi-criteria decision making to obtain scientific and reasonable results. Four wastewater treatment alternatives including reverse osmosis, nano filtration, ion exchange, and chemical precipitation were evaluated and ranked based on economical, technical, environmental/ social aspects. Each criterion includes different indices such as land area, capital cost, sludge disposal issues, operating and maintenance, local suppliers and warranty, system flexibility, required skilled and non skilled man power safety, and etc. The results showed that reverse osmosis achieved the maximum general profits and can be the best choice. Sensitivity analysis can shows the effect of inputs parameters change on the results. Sensitivity analysis was applied for each criterion. The results illustrated that for economic and technical criterion, chemical precipitation and for environment criterion, reverse osmosis were qualified

Iron and manganese contamination: sources, adverse effects and control methods.

This article discusses the problem of iron and manganese contamination, the adverse effects and available control methods. The presence of iron and manganese in water causes serious commercial and health problems. Various treatment methods are available to treat water contaminated with these elements. However, catalytic media is an excellent choice particularly increasing given the preference for non-chemical water treatment. INDION ISR and BIRM are the most popularly used synthetically manufactured catalytic media.

Avaliação da utilização de membranas de troca-iônica na purificação de eritropoetina humana recombinante / Evaluation of the use of membrane ion exchange purification of recombinant human erythropoietin

Nesta avaliação, realizaram-se ensaios cromatográficos de purificação de eritropoetina humana recombinante, a partir do sobrenadante de cultura de células de mamíferos da linhagem CHO (células de ovário de hamster chinês), produtoras deste biofármaco. Compararam-se as membranas comerciais de troca iônica Sartobind (MA) Q e D, com o objetivo de avaliar a sua aplicabilidade a processos de purificação de EPO. Ambas as membranas apresentaram-se capazes de adsorver EPO nas condições avaliadas. EPO foi detectada nas amostras de eluído de ambas as membranas, tendo-se verificado que o imunoensaio do tipo dot-blot foi aquele que forneceu as informações mais conclusivas. Já nas análises de eletroforese, verificou-se um perfil difuso das bandas do eluído das membranas, o que foi creditado à heterogeneidade glicídica da EPO, como anteriormente demonstrado na literatura.

Chemical modification of some cellulosic wastes for increasing their efficiencies as ion exchangers

The affinity of some agricultural wastes, e.g. sunflower stalks, cotton stalks and rice straw toward metal ions uptake is investigated. The effect of chemical modifications, e.g. phosphorylation, sulfonation and phosphosulfonation of these wastes on their efficiency as cation exchangers is also studied. Different variables which affect these chemical modifications, e.g. particle size of residues, quantity of pyridine in reaction medium and percent of chlorosulfonic in the used acid for chemical modification are also evaluated. The prepared cation exchanger from phosphosulfonated of alkali treated sunflower stalks [particle size 125micro m] in presence of pyridine [30 ml] and acids mixture [30% cholorosulfonic acid and 70% phosphorus oxychloride] has the highest efficiency towards metal ions uptake. Modified and nonmodified sunflower stalks have higher efficiency toward metal ions uptake than cotton stalks and rice straw. Infrared spectra of sunflower phosphorylated, sulfonated and phosphosulfonated sunflower stalks are also investigated. New bands at 1200 and 965 cm[-1] and at 1400 cm[-1] are characteristic to C-O-P and C-O-S, respectively. The fragments that obtained from mass spectra are characteristic of six carbon sugar mono ester which produces copious hydroxymethyl furfural group

Drug release mechanism of famotidine time-controlled release pellets / 药学学报

<p><b>AIM</b>To study the drug release mechanism of famotidine time-controlled release pellets and to explore the mechanism of "organic acid-induced type drug delivery system".</p><p><b>METHODS</b>The effects of dissociated and undissociated forms of succinic acid on the drug release behavior of famotidine time-controlled release pellets were studied from the following aspects: ion-exchange reaction, hydration, etc.</p><p><b>RESULTS</b>The dissociated succinic acid created new ionic circumstances by ion-exchange reaction with Eudragit RS100. Whereas undissociated succinic acid increased the flexibility of the film by distribution in the hydrophobic segment of Eudragit RS100. Effects of both forms of the succinic acid could improve the hydration of Eudragit RS film. As a result, the permeability of the film was improved evidently.</p><p><b>CONCLUSION</b>The lag time of famotidine time-controlled release pellets is induced by the hydrophobicity of the film. After water dissolve the organic acid, the dissociated and undissociated forms of succinic acid interact with the film through different ways. These interactions can change the structure of the film. Therefore the permeability of the film will be improved markedly.</p>

Influencia de factores ambientales en la distribución de especies arbóreas en las selvas del sureste de México / Influence of environmental factors on the distribution of tree species in the forests of south-eastern Mexico

We studied the relationship between the distribution of tree species and environmental factors in the Sian Ka’an Biosphere Reserve, south-eastern Mexico. Our main objective was to examine how changes in microtopography and edaphic factors influence the distribution of tree species of medium and low-statured forests. We established 17 plots of 625 m2 and collected data on spatial distribution of individuals with dbh > 5 cm, and the following soil variables: electric conductivity (CE), cationic exchange capacity (CEC), textural class, pH, organic matter (MO), total nitrogen (Nt) and phosphorus availability (P). We used Twinspan to classify the plots and applied indirect (DCA) and direct (CCA) gradient analysis. We found 84 species and 4 433 individuals. MO, texture and CEC varied significantly (p < 0.05) between the high and low parts. DCA and CCA indicated that the species distribution is strongly influenced by the microtopography gradient and the textural class. Using DCA and CCA exclusively on the data of the low parts, two low statured forest types were identified: one characteristic of low zones (soil slightly basic and high percentage of clay), the other surrounded by medium statured forest (soil slightly acid, high CEC, MO and clay).

Se estableció la relación entre la distribución de las especies arbóreas de la selva mediana y baja y los factores edáficos y microtopográficos en la Reserva de la Biosfera de Sian Ka’an. En 17 sitios de muestro de 625 m2 cada uno, se registró la presencia y disposición espacial de los individuos que presentaron un DAP > a 5 cm y las variables edáficas de conductividad eléctrica (CE), capacidad de intercambio catiónico (CIC), clase textural, pH, materia orgánica (MO), nitrógeno total (Nt) y fósforo disponible (P). Para la clasificación de los sitios de muestreo por similitud florística, se empleó el análisis de Twinspan y para la ordenación, los análisis de gradiente indirecto y directo (ACD y ACC, respectivamente). Se registró un total de 4 433 individuos en 84 especies. Aunque la microtopografía es moderada en el área de estudio, diferentes factores edáficos (CIC,arcilla y MO) variaron significativamente (P < 0.05) entre las zonas altas y bajas. Una primera aproximación del ACD y ACC con el total de los datos establece que la distribución de las especies esta determinada por el gradiente microtopográfico y la clase textural. Al realizar una segunda aproximación del ACD y ACC, empleándose solo datos de la zona baja, se muestran dos grupos florísticamente diferentes, uno influenciado por pH ligeramente ácido, alta CIC, MO y arcilla, rodeado de una selva mediana; el otro grupo registra pH básico y alto porcentaje de limo, y se localiza cerca de una selva baja inundable. Las condiciones microtopográficas y edáficas son ecológicamente significativas, ya que están altamente correlacionados con la distribución de las especies vegetales y con las características de la estructura de las comunidades tropicales

Visualization of the Gastric Calcification due to Cancer on Tc-99m DPD and Abdominal CT Images / 대한핵의학회잡지

A 69-year-old woman was presented with progressed dysphagia, gastric soreness and weight loss during 2 months. She was performed abdomen x-ray, EGDS and abdomen CT. Abdomen x-ray demonstrated punctuate calcification on LUQ. EGDS showed an ulceroinfiltrative mass with bleeding on cardia to antrum of stomach. And CT showed diffuse gastric wall thickness with multiple calcifications. Biopsy of the stomach and esophagus during EGDS examination revealed an adenocarcinoma, with signet ring cell type, infiltrating the wall of the stomach and the distal esophagus. Then Bone scan was performed a few days later. It revealed intense uptake in LUQ, corresponding to the calcium containing neoplasm seen on the abdomen x-ray, EGDS and abdomen CT. And there was no evidence of any metastatic lesion and thyroid uptake on the bone scan. There are many reports about accumulation of the tracer in extraosseous lesion, but only a few literatures were reported about gastric calcification in stomach cancer. More over, no reports showed CT images. We are performed many diagnostic examinations and found well correlation between them. The reason of gastric calcification is considered with calcium deposition within extracellular space due to hemorrhage or necrosis. Other possibility offered to explain gastric calcification have been increased blood flow and/or increased neovascularity with capillary leaks of tracer, and specific enzymatic (phosphatases) receptor binding of tracer. So, it was happened ion exchange between intracellular calcium and phosphate groups of tracer.

El ion calcio: su regulación y función en la célula ß pancreática / Ion calcium: its regulation and function in the pancreatic cell

En el presente trabajo se realiza una revisión del conocimiento actual sobre la regulación de las concentraciones intracelulares del ion calcio, los principales mecanismos de entrada y salida de este a través de la membrana plasmática, con especial atención en el intercambiador Na+/Ca2+, y la función de este importante segundo mensajero en la secreción de insulina, así como la muerte celular programada de las células ß pancreáticas(AU)

Clinical placement of glass-ionomer

Glass ionomer cement [GIC] currently available in the market has a similar placement technique but differ in mixing ratio from manufacturer to manufacturer. The property of bioactivity makes it different from all other restorative materials. Special considerations are must for its clinical handling which are discussed in this article

Importância de compostos organossulfurados em sementes de leguminosas e em outros vegetais / Importance of organosulfur compounds in seeds of legumes and in other vegetables

Os compostos organossulfurados, representados pelos peptídeos ´GAMA`-glutamilsulfurados, são encontrados em grande quantidade em vegetais das famílias Alliaceae, Cruciferae e Leguminosae. A seus produtos de metabolização se atribui propriedades organolépticas típicas e quando são ingeridos por mamíferos, causam efeitos biológicos diversos. Estes efeitos são diferentes nestas três famílias, devido à formação de metabólitos secundários que dependem da presença ou ausência de enzimas específicas nestes vegetais. Na família Alliaceae, representada pelo alho e pela cebola, são produzidos compostos sulfurados, que além de serem precursores de aroma e de flavor característicos após a ruptura do tecido vegetal e a ação enzimática, se tornaram conhecidos pelos efeitos benéficos para a saúde humana. A via metabólica percorrida pelos compostos organossulfurados na família Cruciferae, dá origem, além do flavor, a compostos secundários diversos, incluindo o metanotiol e dissulfetos, altamente tóxicos para ruminantes, causando anemia hemolítica. Na família Leguminosae, os dipeptídeos sulfurados são encontrados principalmente nas sementes, sendo que o feijão Phaseolus vulgaris, L., dentre os gêneros estudados, os possui em maior concentração. A ´BETA’-glutamil-S-metil-L-cisteina e a S-metil-L-cisteina livre, podem em conjunto, representar ate ´50 POR CENTO1’ do conteúdo total de metionina presente no feijão, desaparecendo somente por ocasião da sua germinação...