Adsorption of Pentane Insoluble Organic Matter from Oilsands Bitumen onto Clay Surfaces

The effectiveness of commercial oilsands separation processes relies on the water wettability of the solids. Consequently, the interaction between the mineral and organic matter types present in oilsands is of interest. In this work, we report results related to the adsorption of a pentane insoluble fraction from bitumen on kaolinite and illite, the major clay types present in oilsands. We determined adsorption from toluene solution by illite and kaolinite and use a combination of spectroscopic techniques to probe the organic coated clay surfaces to different depths. The results are compared with similar data for equivalent natural fractions from oilsands.     

Anatomy and histology of the A5 pulley

Sustained iontophoresis of NMDA potentiated visual responses for minutes after the application in 16 of 38 cells (42%), peaking 3 min after the end of the application and declining to control levels within 12 min. Potentiation was also seen after application of ACPD (36%, n = 14) and AMPA (29%, n = 14), but not after application of ACh (n = 20). ACh also excites dLGN cells, but does not interact with amino acid receptors, and ACh receptors are not directly involved in the transmission of visual information. We suggest that this modulation is a form of visually induced potentiation which permits dynamic modification of the strength of visual information to be relayed to the cortex depending upon the history of previous activity levels.     

Synergistic effect of compatibilizer in organo‐modified layered silicate reinforced butadiene rubber nanocomposites

We have prepared nanocomposites of intercalated and exfoliated organosilicates in butadiene rubber (BR) by using a two‐stage melt blending process. We used X‐ray diffraction and transmission electron microscopy to examine, respectively, the intergallery spacing of the organosilicates and their dispersion in the BR. Marked enhancements in the mechanical and thermal properties of BR occurred when it incorporated <10 parts of organosilicates and the loading ratio of the organosilicate to dicarboxylic acid‐terminated butadiene oligomer was approximately three. In particular, the addition of 10 parts of organosilicate and 3 parts of compatibilizer in the BR led to a more than four‐fold increase in the tensile strength, a 150% increase in modulus at 100% elongation (M100), and 232 and 410% enhancements in the tear strength and elongation at break, respectively, relative to those of neat BR. The degradation temperature for the BR nanocomposite containing only a 10‐part loading of organosilicate was 51°C higher than that of neat BR; these increases reduced, however, to 9–13°C upon the addition of the CTB compatibilizer. In addition, the relative water vapor permeabilities of the BR nanocomposites containing 10 parts of organosilicate—both in the presence and absence of the compatibilizer—reduced to 20% of that of the neat BR. POLYM. ENG. SCI. 46:80–88, 2006. © 2005 Society of Plastics Engineers     

All-Raman ultralong-haul single-wideband DWDM transmission systems with OADM capability

In this paper, we present a comprehensive experimental investigation of an all-Raman ultrawide single-band transmission system for both 10 and 40 Gb/s line rates. Enabling technologies include forward-Raman pumping of the transmission fiber, counter-Raman pumping of the fiber spans and dispersion compensation modules, wideband dispersion, and dispersion-slope compensation, and modulation formats resistant to both linear and nonlinear impairments. Ultralong-haul (ULH) 128/spl times/10 Gb/s return-to-zero (RZ) and ultrahigh-capacity (UHC) 64/spl times/40 Gb/s carrier-suppressed (CS) RZ transmission are demonstrated for commercially deployed fiber types, including both standard single-mode fiber (SSMF) and nonzero dispersion shifted fibers (NZDSF). The span losses of 23 dB (NZDSF) and 20 dB (SSMF) are consistent with those encountered in terrestrial networks. The optical reaches for 10 Gb/s rate are 4000 km (NZDSF) and 3200 km (SSMF). Using the same distributed Raman amplification (DRA) scheme, UHC over 2.5 Tb/s at a 40-Gb/s per channel rate is also demonstrated for all of the tested fiber types and for optical reaches exceeding 1300 km. We then study the impact of including optical add/drop modules (OADMs) in the transmission system for both 10 and 40 Gb/s channel rates. System performance is characterized by the system margin and the transmission penalty. For all of the experiments shown in this paper, industrial margins and small transmission penalties consistent with operation in commercially deployable networks are demonstrated, showing the feasibility of practical implementation of all-Raman amplified systems for ULH and UHC optical backbones. Attractive features of single-wideband transmission enabled by DRA include simplicity of design, flexible gain and gain-ripple control, good noise performance, and a small system footprint.     

Quantification and segmentation of brain tissues from MR images: aprobabilistic neural network approach

This paper presents a probabilistic neural network based technique for unsupervised quantification and segmentation of brain tissues from magnetic resonance images. It is shown that this problem can be solved by distribution learning and relaxation labeling, resulting in an efficient method that may be particularly useful in quantifying and segmenting abnormal brain tissues where the number of tissue types is unknown and the distributions of tissue types heavily overlap. The new technique uses suitable statistical models for both the pixel and context images and formulates the problem in terms of model-histogram fitting and global consistency labeling. The quantification is achieved by probabilistic self-organizing mixtures and the segmentation by a probabilistic constraint relaxation network. The experimental results show the efficient and robust performance of the new algorithm and that it outperforms the conventional classification based approaches     

Protective effects of a recombinant N-terminal fragment of bactericidal/permeability increasing protein on endotoxic shock in conscious rabbits

Endotoxin (lipopolysaccharide, LPS) can induce shock, multiple organ failure, and death. A recombinant N-terminal fragment of bactericidal/permeability increasing protein, rBPI23, binds with high affinity to gram-negative bacterial LPS and neutralizes its biological activity. We sought to determine the effect of rBPI23 on LPS-induced respiratory dysfunction and cardiovascular depression in conscious rabbits. Rabbits were injected with Escherichia coli O113 LPS (6 micrograms/kg) and treated with rBPI23 (2 mg/kg), vehicle, or control protein after recovery from surgery performed to implant catheters for hemodynamic assessments and intravenous injections. LPS challenge caused respiratory dysfunction including tachypnea, significant decreases in arterial O2 tension (PO2), arterial oxygen content, and an increase in alveolar-arterial O2 gradient (A-aDO2). LPS administration also resulted in profound and prolonged decreases in mean arterial blood pressure and cardiac index. Treatment with rBPI23 prevented LPS-induced respiratory dysfunction and significantly ameliorated the cardiovascular depression. 5 of 16 LPS-challenged animals died of respiratory failure and acidosis, whereas none died in the rBPI23 treated group (p = .11). The results demonstrate that rBPI23 protects animals against LPS-induced cardiopulmonary depression in endotoxic shock.     

Adeno-associated viral vector-mediated gene transfer of human blood coagulation factor IX into mouse liver

Recombinant adeno-associated virus vectors (AAV) were prepared in high titer (10(12) to 10(13) particles/mL) for the expression of human factor IX after in vivo transduction of murine hepatocytes. Injection of AAV-CMV-F.IX (expression from the human cytomegalovirus IE enhancer/promoter) into the portal vein of adult mice resulted in no detectable human factor IX in plasma, but in mice injected intravenously as newborns with the same vector, expression was initially 55 to 110 ng/mL. The expression in the liver was mostly transient, and plasma levels decreased to undetectable levels within 5 weeks. However, long-term expression of human F.IX was detected by immunofluorescence staining in 0.25% of hepatocytes 8 to 10 months postinjection. The loss of expression was likely caused by suppression of the CMV promoter, because polymerase chain reaction data showed no substantial loss of vector DNA in mouse liver. A second vector in which F.IX expression was controlled by the human EF1alpha promoter was constructed and injected into the portal vein of adult C57BL/6 mice at a dose of 6.3 x 10(10) particles. This resulted in therapeutic plasma levels (200 to 320 ng/mL) for a period of at least 6 months, whereas no human F.IX was detected in plasma of mice injected with AAV-CMV-F.IX. Doses of AAV-EF1alpha-F. IX of 2.7 x 10(11) particles resulted in plasma levels of 700 to 3, 200 ng/mL. Liver-derived expression of human F.IX from the AAV-EF1alpha-F.IX vector was confirmed by immunofluorescence staining. We conclude that recombinant AAV can efficiently transduce hepatocytes and direct stable expression of an F.IX transgene in mouse liver, but sustained expression is critically dependent on the choice of promoter.     

Characterization of a Gas Oil Fraction and Its Hydrotreated Products

In this work we explore the chemistry of a gas oil fraction in the mid-boiling range (433-483°C) and its products after hydrotreating at 375, 385, and 400°C. Each sample was fractionated by high performance liquid chromatography (HPLC) based on the elution times for saturate, mono-, di-, and poly-aromatic standards. The HPLC saturate fraction is practically free of aromatic components. The nominal mono- and di-aromatics fractions differ in that the former has a higher molecular weight and H/C ratio cbut lower aromaticity and heteroatom content. The H/C atomic ratios, aromaticities, and average structural parameters of the HPLC poly-aromatic subfractions are virtually the same. Regardless of their structural resemblances they differ substantially in their HPLC elution behavior. This can be attributed to the differences in their oxygen and, especially, nitrogen contents. Hydrogenation produced a significantly greater amount of saturate material having a higher H/C ratio than the original feed. A large part of this increase must result from dealkylation, saturation, or opening of aromatic molecules. This mechanism also produced nominally mono-aromatic compounds from the poly-aromatic species originally present. The effect of hydrogenation on heteroatoms was mixed. While the overall amount of nitrogen was reduced, its concentration in the poly-aromatic fractions actually increased. Overall, oxygen concentration in the product was not much affected by hydrogenation, except that its distribution became skewed towards the more easily eluted HPLC front-fractions. Both thiophenic and sulphide sulphur were significantly reduced in all of the separated fractions.