Spontaneous calf hematoma in a patient with diabetic nephropathy receiving maintenance hemodialysis: A case report and review of the literature

We report the outcome of a 52‐year‐old patient with diabetic nephropathy and receiving maintenance hemodialysis (HD) using low molecular weight heparin (LMWH) as an anticoagulant for 2 years. He presented right lower limb pain accompanied with difficulty in walking for 2 months, and had no history of bleeding tendency or trauma. Physical examination revealed marked swelling and tenderness on his right lower limb. By ultrasound and magnetic resonance imaging (MRI) diagnoses, the calf hematoma was diagnosed and identified with venous thrombosis. Following treatment with heparin‐free HD, the swelling regressed and pain subsided, and a follow‐up MRI showed complete dissolution of hematoma. However, similar symptoms recurred in the right upper limb after 2 months without any predisposition, he was just placed on HD with LMWH, and symptoms regressed following the aforementioned therapy. This suggests that HD patients, especially with diabetic nephropathy having extremity hematoma, should be watched for the development of spontaneous hemorrhage that can be differentially diagnosed by imaging tests, such as MRI, and can be effectively treated with heparin‐free HD.     

Separation of strontium from low level radioactive waste solutions using hydrous manganese dioxide composite materials

⁹⁰Sr is one of the major isotopes present in the low level radioactive liquid waste (LLW) generated during operation of nuclear reactors and spent fuel reprocessing plants. A composite ion exchange material consisting of hydrous manganese oxide and poly methyl methacrylate (PMMA) was developed for removal of strontium from aqueous radioactive waste. The prepared composite material showed very good strontium adsorption properties in aqueous solutions. Sorption of strontium on the composite material as a function of pH, equilibration time and strontium ion concentrations were studied. The process of sorption of strontium from solution was analysed using different isotherm models like Langmuir, D-R and Freundlich. Four different error functions were employed to find out the most suitable isotherm model to represent the experimental data and it was found that Freundlich model best fits the sorption of strontium on the composite material. Analysis of the data obtained from the sorption kinetics studies showed that the data fitted better to the pseudo-second order kinetic model. Lab scale column performance study of the composite material revealed that the material could be effectively used in column operations to remove strontium from LLW solutions.     

Synthesis and characterization of cobalt ferrocyanides loaded on organic anion exchanger

Transition metal ferrocyanides have important applications in the selective removal of radioactive caesium from low level and intermediate level radioactive liquid waste streams. The microcrystalline nature of these materials renders them useless for application in column mode operations. Special preparation procedures have been developed to prepare granular solids by in situ precipitation of metal ferrocyanides on organic anion exchangers, which is suitable for column mode operations. The elemental compositions of the metal ferrocyanides precipitated inside the pores of anion exchanger were determined by analysing the dissolved samples using ICP-AES system and flame photometer. From the XRD and EDX analyses and the elemental composition of the synthesized materials, the nature of the compound formed inside the anion exchanger was found to be cobalt ferrocyanide. From SEM analysis of the samples, the particle size of the cobalt ferrocyanide precipitated inside the anion exchanger was found to be much less than that of cobalt ferrocyanide precipitated outside. The efficiency of these materials for removal of Cs was evaluated by measuring the distribution coefficient (Kd), ion exchange capacity and kinetics of Cs uptake. The Kd of the materials loaded on anion exchanger was found to be of the order of 10⁵ ml/g. The Cs uptake kinetics of the materials loaded on anion exchanger was slower than that of precipitated materials. The ion exchange capacity of the cobalt ferrocyanide loaded on anion exchanger was found to be much higher than that of the precipitated cobalt ferrocyanide.     

Photogalvanic conversion of solar energy into electrical energy by using NaLS-xylose-methylene blue system

Photogalvanic cells having different surfactants, reductants and photosensitizers have been tried to get the better electrical output and storage capacity. Through literature survey shows that system having NaLS as a surfactant, xylose as a reductant and methylene blue as a photosensitizer has not been explored to get the required results and achievements so the efforts have been made by the system in photogalvanic cell to get better electrical output (i.e. photopotential 834 mV, photocurrent 90 μA, power and power at power point are 75.06 μW and 32.72 μW) and also good storage capacity i.e. 55 min in dark. The observed conversion efficiency and fill factor for this is 0.31%, 0.363%. The effect of different parameter like pH, diffusion length on electrical output of the cell was also studied and tentative mechanism for the generation of photocurrent was also purposed.     

Study of different approaches for management of contaminated emulsified aqueous secondary waste

The underlying objective governing the management of radioactive waste is protection of human being and the environment, now as well as in the future. As a waste management philosophy, utmost emphasis is given to waste volume minimization at all stages of design, operation and maintenance [1]. The development of innovative treatment processes for low and intermediate level wastes (LLW and ILW) in recent times has focused on volume reduction as one of the main objectives [2]. During reprocessing of spent fuel, an optimized mixture of tri-n-butyl phosphate (TBP) and dodecane is used as an extracting agent for actinides. During their repeated use, solvent undergoes chemical/radiolytic degradation, loosing its efficiency and hence to be discarded as spent organic solvent waste. This waste is presently being treated by alkaline hydrolysis process where spent solvent is refluxed with concentrated sodium hydroxide solution at 110°C [3]. TBP component of the spent solvent waste gets hydrolyzed and is converted into sodium salt of di-butyl phosphate (DBP). The other products obtained during hydrolysis include sodium salt of mono-butyl phosphate (MBP), butanol and phosphoric acid. Dodecane component of the spent solvent waste does not take part in the hydrolysis reaction and appears as a clear phase. The dodecane waste thus separated is subjected for thermal destruction by incineration. The emulsified aqueous layer thus obtained retains most of the activity present in the spent solvent waste. The present paper describes experimental studies performed to look for various approaches for management of this type of waste.     

Application of lipase immobilized on nylon‐6 for the synthesis of butyl acetate by transesterification reaction in n‐heptane

A purified alkaline thermotolerant bacterial lipase from Bacillus coagulans BTS‐3 was immobilized on nylon‐6 matrix activated by glutaraldehyde. The matrix showed ～ 70% binding efficiency for lipase. The bound lipase was used to perform transesterification in n‐heptane. The reaction studied was conversion of vinyl acetate and butanol to butyl acetate and vinyl alcohol. Synthesis of butyl acetate was used as a parameter to study the transesterification reaction. The immobilized enzyme achieved ～ 75% conversion of vinyl acetate and butanol (100 mmol/L each) into butyl acetate in n‐heptane at 55°C in 12 h. When alkane of C‐chain lower or higher than n‐heptane was used as an organic solvent, the conversion of vinyl acetate and butanol to butyl acetate decreased. During the repetitive transesterification under optimal conditions, the nylon bound lipase produced 77.6 mmol/L of butyl acetate after third cycle of reuse. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007