Towards a global historical emission inventory for selected PCB congeners--a mass balance approach 3. An update

Previously published estimates of the global production, consumption and atmospheric emissions of 22 individual PCB congeners [Breivik K, Sweetman A, Pacyna JM, Jones KC. Towards a global historical emission inventory for selected PCB congeners - a mass balance approach. 1. Global production and consumption. Sci Total Environ 2002a; 290: 181-198.; Breivik K, Sweetman A, Pacyna JM, Jones KC. Towards a global historical emission inventory for selected PCB congeners--a mass balance approach. 2. Emissions. Sci Total Environ 2002b; 290: 181-198.] have provided useful information for later studies attempting to interpret contaminant levels in remote areas as well as in the global environment. As a result of the need for more contemporary emission data (following the year 2000), an update of this emission database is presented. This exercise takes into account new information on PCB production in Poland, as well as new data on the chemical composition of various technical mixtures for which less information had been available. The methodology to estimate temporal trends of PCB emissions associated with various types of PCB usage is improved. Projected emissions up to year 2100 are presented to facilitate predictions of future environmental exposure. The national emission data for each of the 114 countries considered is spatially resolved on a 1 degrees x1 degrees grid for each congener and year, using population density as a surrogate.     

Axisymmetric impinging jet excited by a synthetic jet system

A controlled impinging jet is a promising tool for various heat/mass transfer applications, such as drying technologies or cooling of highly loaded electronic devices or gas turbine blades. An axisymmetric air jet was excited using a system of four synthetic jets distributed around the circumference of the primary nozzle. First, the control synthetic jets were measured alone. After an adjustment, the primary axisymmetric jet was excited to the helical or bifurcating modes, and its behavior was studied experimentally including an impingement effect to the wall. For comparison purposes, a reference steady (unforced) jet from the same nozzle was also measured. The flow visualization, hot-wire anemometry, PIV, and naphthalene sublimation techniques were used. The main purpose was to investigate the influence of the actuation on the impingement heat transfer at the Reynolds numbers 1600 and 5000.The effects of the Strouhal number and nozzle-to-wall spacing on a distribution of the local heat transfer were evaluated. The most significant effects were found at the Strouhal numbers 0.14–0.32 at the ratio of the control to primary jet momentum rates only 0.24–2.4%. Under small nozzle-to-wall spacing H/D = 2, the excitation led to heat transfer increase in the stagnation area – the most prominent enhancement 40% was found at the stagnation point. Under moderate nozzle-to-wall spacing H/D = 6, the excitation made more uniform the Nusselt number distribution by means of a substantial reduction of the stagnation heat transfer rate.     

Biodegradable nanocomposites of amyloid fibrils and graphene with shape-memory and enzyme-sensing properties

Graphene has exceptional mechanical and electronic properties, but its hydrophobic nature is a disadvantage in biologically related applications. Amyloid fibrils are naturally occurring protein aggregates that are stable in solution or under highly hydrated conditions, have well-organized supramolecular structures and outstanding strength. Here, we show that graphene and amyloid fibrils can be combined to create a new class of biodegradable composite materials with adaptable properties. This new composite material is inexpensive, highly conductive and can be degraded by enzymes. Furthermore, it can reversibly change shape in response to variations in humidity, and can be used in the design of biosensors for quantifying the activity of enzymes. The properties of the composite can be fine-tuned by changing the graphene-to-amyloid ratio.     

Determination of citric and isocitric acids in fruit juices by capillary isotachophoresis

An isotachophoretic method was developed to determine directly citric and isocitric acids in juice samples. Isotachophoretic separations were performed using a Villa Labeco ZKI 02 column-coupling isotachophoretic analyzer equipped with a conductivity detector. The analytical capillary (160 mmǴ.3 mm I.D.) was connected with a preseparation capillary (80 mmǴ.8 mm I.D.). The leading electrolyte contained hydrochloric acid (10 mmol/l), #-alanine (pH 3.0), and hydroxyethylcellulose (0.1%). The terminating electrolyte was 5 mmol/l acetic acid. Limit of quantitation for citric acid in the preseparation capillary was 20 mg/l and for isocitric acid in the analytical capillary was 1.2 mg/l.     

Influence of Paclitaxel and Doxorubicin Therapy of ßIII-Tubulin,Carbonic Anhydrase IX,and Survivin in Chemically Induced Breast Cancer in Female Rat

Breast cancer is the most common cancer in females. The aim of this study was to determine the effect of paclitaxel (PTX) and doxorubicin (DOX) therapy on the βIII-tubulin, carbonic anhydrase IX (CA IX), and survivin expression in chemically-induced rat mammary tumors. Animals with induced mammary carcinogenesis were randomly divided into treatment groups and an untreated group. The total proportion of tumors, the proportion of carcinoma in situ (CIS), and invasive carcinoma (IC) were evaluated. Protein expression in tumor tissue was determined using IHC. Statistical analysis of the data, evaluated by Fisher-exact test and unpaired t-test. Significantly increased levels of proteins in the tumor cells were confirmed using the IHC method for all studied proteins. The expression of βIII-tubulin, CA IX, and survivin increased significantly after treatment with both cytostatics (PTX and DOX). Depending on the type of tumor, a significant increase in all proteins was observed in IC samples after PTX treatment, and CA IX expression after DOX treatment. In CIS samples, a significant increase of βIII-tubulin and survivin expression was observed after a DOX treatment. The results suggest that βIII-tubulin, survivin, and CA IX may be significant drug resistance markers and the clinical regulation of their activity may be an effective means of reversing this resistance.     

A neural network approach for safety and collision avoidance in robotic systems

A major factor which has limited the application of robots in industrial and human service applications has been the lack of robust sensing and control algorithms for detection and prevention of collision conditions. This paper discusses an approach to the collision avoidance control of robots using a neural network methodology for the integration of sensory input data from the robot's environment. The paper presents a formulation of the collision avoidance problem using the occupancy grid formulation, and discusses the use of a combination of Dempster-Shafer inference and neural networks in fusing the sensory information and making robot movement decisions. Initial studies have shown this approach to be both robust and computationally tractable in providing enhanced safety capabilities.     

Kinetics of phosphorus segregation in 2.7Cr-0.7Mo-0.3V steels with different phosphorus contents

The phosphorus grain boundary segregation kinetics during tempering at 680°C and aging at 500°C of 2.7Cr-0.7Mo-0.3V steels with phosphorus mass contents of 0.004, 0.014, and 0.027 % was investigated. To determine the grain boundary concentrations of phosphorus the Auger electron spectroscopy was used. Chemical compositions of carbide particles were determined by means of EDX/STEM. Xu Tingdong's and McLean's models of non-equilibrium and equilibrium segregations, respectively, were used to analyze experimental data. It was shown that a phosphorus grain boundary enrichment during tempering was mainly caused by non-equilibrium segregation. During aging the mechanism of the equilibrium grain boundary segregation was prevalent. Slow phosphorus segregation kinetics was observed in the experimental steels during aging.     

Yeast sequencing reports. Genes of the linear mitochondrial DNA of Williopsis mrakii: Coding sequences for a maturase-like protein,a ribosomal protein VAR1 homologue,cytochrome oxidase subunit 2 and methionyl tRNA

The mitochondrial DNA (mtDNA) in some yeasts has a linear structure with inverted terminal repeats closed by a single-stranded loop. These mtDNAs have generally a constant gene order, beginning with a small ribosomal RNA gene at the right end and terminating with a cytochrome oxidase subunit 2 gene (COX2) at the left end, independently of the wide variation in genome size. In the mtDNAs from several species of the genus Williopsis, we found an additional open reading frame, ORF1, which was homologous to the Saccharomyces cerevisiae RF1 gene encoding a group I intron maturase-like protein. ORF1 genes from W. mrakii and W. suaveolens were mapped and sequenced. Next to ORF1, COX2 and methionyl tRNA genes were present on the opposite strand. The same relative positions of genes in the mtDNAs so far examined suggests that the constancy of gene order is generally conserved also at the level of individual tRNA genes. We identified another open reading frame, ORF2, in W. mrakii mtDNA. It was mapped next to the cytochrome oxidase subunit 3 gene. Rich in adenine-thymine bases, ORF2 appears to be a homologue of the VAR1 gene which codes for a small ribosomal subunit protein in S. cerevisiae mitochondria. Nucleotide sequences data have been deposited in the EmBL data library under the following Accession Numbers: X66594 (Apocytochrome b and ORF2 genes of W. mrakii), X66595 (ORF1, tRNA-Met and COX2 genes of W. mrakii), X73415 (tRNA-Met and COX2 genes of W. suaveolens), X73416 (ORF1 gene of W. suaveolens) and X73414 (tRNA-Met and COX2 genes of P. jadinii).