Adsorption onto fluidized powdered activated carbon flocs-pACF

This work presents a new adsorption technique where the adsorbent (powdered activated carbon-PAC) is in the form of suspended flocs formed with water-soluble polymer flocculants. Thus, the adsorption of a typical dye, methylene blue (MB), was studied onto polyacrylamide flocs of PAC (PACF) in a fluidized bed reactor. The technique is based on the fact that the adsorption capacity of PAC does not decrease after flocculation because the adsorbed polymer occupies only a few surface sites, in the form of trains, loops, and tails. Moreover, the adsorption was found to proceed through a rapid mass transfer of MB to the adsorbing PAC flocs, in the same extent as onto PAC. Because of the rapid settling characteristics of the aggregates formed, the two phase separations, loaded PAC and solution, become easier. Thus, the technique offers the advantages of conducting simultaneously both adsorption and solid/liquid separation all in one single stage. Results obtained showed that high MB removal values can be attained in a fluidized bed reactor (>90%) and that PACF presents a much higher adsorption capacity (breakthrough points) than granulated activated carbon (GAC) in the same adsorbing bed. It is believed that this technique highly broadens the potential of the use of powdered activated carbon or other similar ultrafine adsorbents.     

Effect of light on the electrocatalytic reduction of furfural on copper electrode in N,N-dimethylformamide

Electrocatalytic reduction of furfural (2-furan-carboxaldehyde) has been investigated on copper electrode in N,N-dimethylformamide. The onset of the electron transfer process starts at around −0.80 V (SCE). Linear correlation has been found between the cathodic current peak (j_P) and furfural concentration. The influence of the incidence of light on the charge transfer process is also discussed. Spectroscopic evidences obtained by NMR indicate that the main product of electrocatalytic reduction of furfural was furfuryl alcohol in the dark and under illumination.     

Quantitative effects of acquisition duration and temporal resolution on the measurement accuracy of prostate dynamic contrast-enhanced MRI data: a phantom study

Objectives

The aim of this study was to investigate the effect of the temporal resolution (T _res) and acquisition duration (AD) on the measurement accuracy of contrast concentration–time curves (CTCs), and derived phenomenological and pharmacokinetic parameter values, in a dynamic contrast-enhanced MRI experiment using a novel phantom test device.

Materials and methods

‘Ground truth’ CTCs were established using a highly precise optical imaging system. These precisely known CTCs were produced in an anthropomorphic environment, which mimicked the male pelvic region, and presented to the MRI scanner for measurement. The T _res was varied in the range [2–24.4 s] and the AD in the range [30–600 s], and the effects on the measurement accuracy were quantified.

Results

For wash-in parameter measurements, large underestimation errors (up to 40%) were found using T _res values ≥16.3 s; however, the measured wash-out rate did not vary greatly across all T _res values tested. Errors in derived K ^trans and v _e values were below 14 and 12% for acquisitions with {T _res ≤ 8.1 s, AD ≥ 360 s} and {T _res ≤ 16.3 s, AD ≥ 360 s}, respectively, but increased dramatically outside these ranges.

Conclusions

Errors in measured wash-in, wash-out, K ^trans, and v _e parameters were minimised using T _res ≤ 8.1 s and AD ≥ 360 s, with large errors recorded outside of this range.

     

A nonbalanced translocation (10;16) demonstrated by FISH analysis in a case of alveolar adenoma of the lung

Trans-fatty acids increase serum LDL-cholesterol and decrease HDL-cholesterol levels in humans when substituted for cis unsaturated fatty acids in the diet. Trans-fatty acids also increase lipoprotein (a) levels relative to other fatty acids. The effects on LDL and HDL may be mediated by the cholesteryl ester transfer protein.     

Broadmark: A Testing Framework for Broad-Phase Collision Detection Algorithms

Research in the area of collision detection permeates most of the literature on simulations, interaction and agents planning, being commonly regarded as one of the main bottlenecks for large-scale systems. To this day, despite its importance, most subareas of collision detection lack a common ground to test and validate solutions, reference implementations and widely accepted benchmark suites. In this paper, we delve into the broad-phase of collision detection systems, providing both an open-source framework, named Broadmark, to test, compare and validate algorithms, and an in-deep analysis of the main techniques used so far to tackle the broad-phase problem. The technical challenges of building this framework from the software and hardware perspectives are also described. Within our framework, several original and state-of-the-art implementations of CPU and GPU algorithms are bundled, alongside three benchmark scenes to stress algorithms under several conditions. Furthermore, the system is designed to be easily extensible. We use our framework to bring out an extensive performance comparison among assembled solutions, detailing the current CPU and GPU state-of-the-art on a common ground. We believe that Broadmark encompasses the principal insights and tools to derive and evaluate novel algorithms, thus greatly facilitating discussion about successful broad-phase collision detection solutions.     

Comparison of Methodologies for the Extraction of Bacterial DNA from Mussels—Relevance for Food Safety

The control of the microbiological quality of bivalve molluscs assumes particular importance because they are among the most produced seafood products and mostly consumed as a whole, raw, or lightly cooked. The composition of the bacterial community associated with bivalves depends mostly on the microbiology of the surrounding environment at growing sites. Once the relationship between microbiology of bivalves and environment is established, a better classification and monitoring of the shellfish beds and evaluation of depuration strategies can be achieved. In this work, we tested if the methods of DNA extraction commonly used for the culture-independent microbiological analysis of sediment and water could be used directly, or with modifications, for the analysis of bacteria in mussels. The commercial kits Genomic DNA Purification Kit (MBI Fermentas, Vilnius, Lithuania), UltraClean^TM Soil DNA Isolation Kit (MOBIO Laboratories, Inc., Carlsbad, CA) and the method described by Griffiths and collaborators for DNA/RNA co-extraction were compared. The efficiency of extraction was assessed by DNA fluorescence and the denaturing gradient gel electrophoresis gel patterns of 16S ribosomal RNA gene fragments were used to compare the reproducibility and representativeness of the extraction methods. Results showed that the DNA/RNA co-extraction method with modifications was the most suitable. However, the results must be interpreted in the light of the purpose of the study and the relevance of maximizing extraction yield or diversity estimate, without compromising reproducibility. To our knowledge, this was the first attempt to transpose the procedure currently used for DNA extraction from sediments or waters, to the analysis of whole mussels.