Polyurethane from kraft lignin

The condensation of lignin with hexamethylene diisocyanate (HDI) or of a mixture of lignin-poly(ethylene oxide) (PEO) with HDI was investigated. The lignin used in this study was a kraft lignin from Pinus maritima, and was obtained from black liquor by acidification, filtration and vacuum drying. Thermogravimetric analysis was carried out to compare the weight loss against temperature of polyurethanes based on kraft lignin and hexamethylene diisocyanate, or of mixed polyurethanes lignin-PEO-HDI, with that of kraft lignin alone. It was shown that lignin can react with isocyanates in rather mild conditions to give polyurethanes, confirming previous results performed with model molecules. Some mechanical properties (Young's modulus and rupture strength) and glass transition temperature were also measured on the various above materials. In all cases it was concluded that lignin participates to the polycondensation reaction. As to rigid foams, it was found that polyurethanes prepared with oxypropylated glycerol, ethylene glycol and kraft lignin, in the weight proportions of 100/30/15, and HDI had good dimensional stability, and thermal and mechanical properties comparable to those of equivalent industrial materials.     

Comments on "Call Blocking Probability and Bandwidth Utilization of OFDM Subcarrier Allocation in Next-generation Wireless Networks"

We claim that the Markovian model proposed by J.-C. Chen and W.-S.E. Chen (2006) is not suitable for the intended physical system. A more adequate model is proposed, which additionally offers important advantages that are discussed in this letter.     

Physical and sensory properties of low-salt phosphate-free frankfurters composed with various ingredients

The physical properties and sensory attributes of phosphate-free frankfurters were examined using response surface methodology by varying the amounts of five compositional variables: salt, modified tapioca starch-, sodium citrate (NaC)- and wheat bran and fat in the batter. Altogether, 20 different types of frankfurters were prepared. When the frankfurters were made without phosphate, additional non-meat ingredients were needed at salt contents of less than 1.5%. Modified tapioca starch and sodium citrate decreased frying loss, with the former also improving water and fat binding.     

Real-time PCR-based methods for detection of Mycobacterium avium subsp. paratuberculosis in water and milk

A real-time PCR assay for quantitative detection of Mycobacterium avium paratuberculosis has been developed. It targets and amplifies sequences from the IS900 insertion element which is specific for this bacterium, and includes an internal amplification control. The assay was tested against 18 isolates of M. avium paratuberculosis, 17 other mycobacterial strains, and 25 non-mycobacterial strains, and was fully selective. It is capable of detecting <3 genomic DNA copies with 99% probability or alternatively, using cells directly in the reaction, 12 cells can be detected with 99% probability. Using prior centrifugation, the assay was able to consistently and quantifiably detect 10(2) M. avium paratuberculosis cells in 20 ml artificially contaminated drinking water. With a simple detergent and enzymatic sample pretreatment before centrifugation and nucleic acid extraction, the assay was able to consistently detect 10(2) M. avium paratuberculosis in 20 ml artificially contaminated semi-skimmed milk. The assay will be a useful addition to the range of diagnostic tools available for the study of M. avium paratuberculosis.     

Evaluation of the functional efficacy of an antioxidative probiotic in healthy volunteers

Background  

In persons without clinical symptom it is difficult to assess an impact of probiotics regarding its effect on health. We evaluated the functional efficacy of the probiotic Lactobacillus fermentum ME-3 in healthy volunteers by measuring the influence of two different formulations on intestinal lactoflora, fecal recovery of the probiotic strain and oxidative stress markers of blood and urine after 3 weeks consumption.     

High-pressure processing applied to cooked sausages: bacterial populations during chilled storage

Vacuum-packaged cooked sausages were pressurized at 500 MPa for 5 or 15 min at mild temperature (65 degrees C) and later stored at 2 and 8 degrees C for 18 weeks. Counts of aerobic mesophiles and psychrotrophs, lactic acid bacteria, enterobacteria, Baird-Parker microbiota, and Listeria spp. were determined 1 day and 3, 6, 9, 12, 15, and 18 weeks after treatment and compared with those of cooked sausages treated at 80 to 85 degrees C for 40 min. Pressurization generated reductions of about 4 log CFU/g in psychrotrophs and lactic acid bacteria. Enterobacteria and Listeria proved the most pressure sensitive; insignificant or no growth was detected throughout the study. Heat treatment inactivated psychrotrophs and enterobacteria similarly to pressure treatment. Listeria monocytogenes and enterotoxigenic Staphylococcus aureus were not found in treated samples. In general, there was no significant difference in counts of any bacterial populations either among treatments or between storage temperatures. High-pressure processing at mild temperature is an effective preservation method that can replace heat pasteurization applied to some cooked meat and poultry products after packaging.     

Immuno-allergic hemolytic anemia connected with streptomycin

The distribution volume of 125l-diatrizoate in rat tissues was studied 5 seconds to 5 minutes after intravenous injection and 5 seconds to 2 minutes after intra-arterial injection. Immediately after injection, diatrizoate was distributed into a larger volume than plasma. Marked temporal changes in the distribution volume of individual tissues occurred during the first 2 minutes. At 5 minutes, the diatrizoate space approached the total extracellular fluid volume, with more than 80% of the contrast agent remaining outside the blood vessels. Thus the relative magnitude of contrast enhancement of a tissue appears to be related to the volume of the rapidly equilibrating extracellular space. Intra-arterial administration can significantly overload muscle with contrast material for about 2 minutes. This and other temporal changes in contrast distribution may prove useful in contrast-enhanced computed tomography using short scanning times.     

Two Triangulation Methods Based on Edge Refinement

In this paper two curvature adaptive methods of surface triangulation are presented. Both methods are based on edge refinement to obtain a triangulation compatible with the curvature requirements. The first method applies an incremental and constrained Delaunay triangulation and uses curvature bounds to determine if an edge of the triangulation is admissible. The second method uses this function also in the edge refinement process, i.e. in the computation of the location of a refining point, and in the re-triangulation needed after the insertion of this refining point. Results are presented, comparing both approaches.     

Corrosion protection with polyaniline and polypyrrole as anticorrosive additives for epoxy paint

Accelerated immersion tests have been carried out in the laboratory to investigate the performance of polyaniline emeraldine salt and polypyrrole composite with carbon black as additives of an epoxy paint coating. The steel panels coated with paint modified with polyaniline emeraldine salt presented the best protection after 720 h of exposure in 3.5% NaCl solution. The results indicated that this conducting polymer might works as both corrosion inhibitor and adhesion promoter. The protective mechanism imparted by conducting polymers is also discussed.