Hepatoblastoma in an Adult with Biliary Obstruction and Associated Portal Venous Thrombosis

We present a case of adult hepatoblastoma. This young female presented with severe acute cholangitis. Preoperative diagnosis was common bile duct (CBD) obstruction with portal vein thrombosis. On exploration she had a tumor mass in the CBD. The unusual features of this case are discussed in this report

Microwave-assisted crystallization for improved process control during crystallization

status: publishe

Microwave assisted direct nucleation control for batch crystallization: Crystal size control with reduced batch time

© 2015 American Chemical Society. Direct nucleation control (DNC) is a feedback control strategy, based on an in situ measurement of the number of particles. In batch cooling crystallization processes, the DNC approach utilizes temperature cycling to control the supersaturation profile during the batch. As a result of this cycling, product crystals with a large mean size and a narrow size distribution can be achieved due to the dissolution of undesired fines. However, implementing the temperature cycles may come at the expense of significantly prolonged batch times due to conventional heat transfer limitations and practical limitations for implementing actuation for both conventional heating and cooling. In this work, microwave heating in combination with DNC is presented to eliminate limitations of conventional heating and further improve the effectiveness of DNC. The results show a very rapid response when using microwave heating, which allowed for improved effectiveness of DNC. In particular, batch times under DNC could be reduced by 50% using microwave heating compared to conventional heating, producing crystals with a narrow distribution similar to experiments with conventionally heated DNC.status: publishe

Extracellular polymeric substances govern the surface charge of biogenic elemental selenium nanoparticles

International audienc

Multiparameter Investigation of Laser-Induced Nucleation of Supersaturated Aqueous KCl Solutions

Various mechanisms have been proposed to explain the nonphotochemical laser-induced nucleation (NPLIN). Identifying the dominant mechanism requires addressing a large set of experimental parameters with a statistically significant number of samples, forced by the stochastic nature of nucleation. In this study, with aqueous KCl system, we focus on the nucleation probability as a function of laser wavelength, laser intensity, and sample supersaturation, whereas the influence of filtration and the laser-induced radiation pressure on NPLIN activity is also studied. To account for the nucleation stochasticity, we used 80–100 samples. The NPLIN probability showed an increase with increasing laser intensity. The results are different from the previous report, as a supersaturation independent intensity threshold is not observed. No dependence of the NPLIN probability on the laser wavelength (355, 532, and 1064 nm) was observed. Filtration of samples reduced the nucleation probability suggesting a pronounced role of impurities on NPLIN. The magnitude and the propagation velocity of the laser-induced radiation pressure were quantified using a pressure sensor under laser intensities ranging from 0.5 to 80 MW/cm². No correlation was found between the radiation pressure and NPLIN at our unfocused laser beam intensities ruling out the radiation pressure as a possible cause for nucleation

Extracellular Polymeric Substances Govern the Surface Charge of Biogenic Elemental Selenium Nanoparticles

The origin of the organic layer covering colloidal biogenic elemental selenium nanoparticles (BioSeNPs) is not known, particularly in the case when they are synthesized by complex microbial communities. This study investigated the presence of extracellular polymeric substances (EPS) on BioSeNPs. The role of EPS in capping the extracellularly available BioSeNPs was also examined. Fourier transform infrared (FT-IR) spectroscopy and colorimetric measurements confirmed the presence of functional groups characteristic of proteins and carbohydrates on the BioSeNPs, suggesting the presence of EPS. Chemical synthesis of elemental selenium nanoparticles in the presence of EPS, extracted from selenite fed anaerobic granular sludge, yielded stable colloidal spherical selenium nanoparticles. Furthermore, extracted EPS, BioSeNPs, and chemically synthesized EPS-capped selenium nanoparticles had similar surface properties, as shown by ζ-potential versus pH profiles and isoelectric point measurements. This study shows that the EPS of anaerobic granular sludge form the organic layer present on the BioSeNPs synthesized by these granules. The EPS also govern the surface charge of these BioSeNPs, thereby contributing to their colloidal properties, hence affecting their fate in the environment and the efficiency of bioremediation technologies