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Selected AbstractsAutomated ultrasound-assisted method for the determination of the oxidative stability of virgin olive oilEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 2 2007José Platero-López Abstract A fast and automated method is proposed for determining the oxidative stability of virgin olive oil by using ultrasound. The ultrasound microprobe (3,mm in diameter) was directly immersed into the olive oil sample contained in a test tube. The most influential variables in the oxidation process, namely pulse amplitude, duty cycle, irradiation time, and sample amount, were optimized. The oil absorbance at 270,nm was continuously monitored by oil recirculation through a 0.1-mm path length flow cell connected to a fiber optic microspectrometer. This short path length allowed the direct monitoring of absorbance without needing any sample dilution. The ultrasound energy was applied during 35,min, and the resulting increase in absorbance was continuously monitored. The difference between the final and the initial absorbance at 270,nm of a set of virgin olive oil samples was closely correlated with their oxidative stability calculated by the Rancimat method (R2,=,0.9915). The resulting equation enabled the prediction of the oxidative stability of virgin olive oil in a short period of time (35,min), by using a simple, inexpensive, automatic and easy-to-use system. [source] Organic Field-Effect Transistors: Planarization of Polymeric Field-Effect Transistors: Improvement of Nanomorphology and Enhancement of Electrical Performance (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 14 2010Mater. Contact geometry plays an important role in charge injection and transport in organic field-effect transistors. On page 2216, T. Kowalewski, L. M. Porter, et al. show a dramatic effect of electrode planarization on the polymer morphology at the contact edges and a resulting increase in fi eld-effect mobility in short channel length devices, and a corresponding decrease in contact resistance. The cover image shows atomic force micrograph of individual polymer nanofi brils spanning the length of a 10 µm channel transistor with planarized contacts. [source] Carbon sequestration under Miscanthus: a study of 13C distribution in soil aggregatesGCB BIOENERGY, Issue 5 2009MARTA DONDINI Abstract The growing of bioenergy crops has been widely suggested as a key strategy in mitigating anthropogenic CO2 emissions. However, the full mitigation potential of these crops cannot be assessed without taking into account their effect on soil carbon (C) dynamics. Therefore, we analyzed the C dynamics through four soil depths under a 14-year-old Miscanthus plantation, established on former arable land. An adjacent arable field was used as a reference site. Combining soil organic matter (SOM) fractionation with 13C natural abundance analyses, we were able to trace the fate of Miscanthus -derived C in various physically protected soil fractions. Integrated through the whole soil profile, the total amount of soil organic carbon (SOC) was higher under Miscanthus than under arable crop, this difference was largely due to the input of new C. The C stock of the macroaggregates (M) under Miscanthus was significantly higher than those in the arable land. Additionally, the C content of the micro-within macroaggregates (mM) were higher in the Miscanthus soil as compared with the arable soil. Analysis of the intramicroaggregates particulate organic matter (POM) suggested that the increase C storage in mM under Miscanthus was caused by a decrease in disturbance of M. Thus, the difference in C content between the two land use systems is largely caused by soil C storage in physically protected SOM fractions. We conclude that when Miscanthus is planted on former arable land, the resulting increase in soil C storage contributes considerably to its CO2 mitigation potential. [source] The benefits of switching smoking cessation drugs to over-the-counter statusHEALTH ECONOMICS, Issue 5 2002Theodore E. Keeler This paper provides an analysis of the benefits to society from the conversion of nicotine replacement drugs (nicotine patches and gum) in 1996 from sale by prescription only in the United States to over-the-counter (OTC) sales. To estimate these benefits, we first estimate statistical demand functions for nicotine patches and gum. Second, we calculate the effects of OTC conversion on sales of each type of nicotine replacement drug. Third, we survey the literature on the effects of nicotine replacement drugs on total quits of cigarette smoking. Fourth, we survey the literature on the effects of quits achieved on expected lifespan, and on the estimated monetary value of longer lives from smoking cessation. Finally, we use all this evidence to calculate the value of the social benefits of the OTC conversion to the US. As a result of the OTC conversion, consumption of nicotine replacement drugs has increased substantially, by 78,92% for nicotine patches and 180% for nicotine gum. We estimate that the resulting increase in smoking cessation generated annual net social benefits of the order of magnitude of $1.8,2 billion, based on conservative estimates both of the number of quits achieved and the value of added quality-adjusted life years from the reduced smoking. Copyright © 2002 John Wiley & Sons, Ltd. [source] A pseudospectral Fourier method for a 1D incompressible two-fluid modelINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 6 2008H. Holmås Abstract This paper presents an accurate and efficient pseudospectral (PS) Fourier method for a standard 1D incompressible two-fluid model. To the knowledge of the authors, it is the first PS method developed for the purpose of modelling waves in multiphase pipe flow. Contrary to conventional numerical methods, the PS method combines high accuracy and low computational costs with flexibility in terms of handling higher order derivatives and different types of partial differential equations. In an effort to improve the description of the stratified wavy flow regime, it can thus serve as a valuable tool for testing out new two-fluid model formulations. The main part of the algorithm is based on mathematical reformulations of the governing equations combined with extensive use of fast Fourier transforms. All the linear operations, including differentiations, are performed in Fourier space, whereas the nonlinear computations are performed in physical space. Furthermore, by exploiting the concept of an integrating factor, all linear parts of the problem are integrated analytically. The remaining nonlinear parts are advanced in time using a Runge,Kutta solver with an adaptive time step control. As demonstrated in the results section, these steps in sum yield a very accurate, fast and stable numerical method. A grid refinement analysis is used to compare the spatial convergence with the convergence rates of finite difference (FD) methods of up to order six. It is clear that the exponential convergence of the PS method is by far superior to the algebraic convergence of the FD schemes. Combined with the fact that the scheme is unconditionally linearly stable, the resulting increase in accuracy opens for several orders of magnitude savings in computational time. Finally, simulations of small amplitude, long wavelength sinusoidal waves are presented to illustrate the remarkable ability of the PS method to reproduce the linear stability properties of the two-fluid model. Copyright © 2008 John Wiley & Sons, Ltd. [source] The effect of nitric oxide on cyclooxygenase-2 (COX-2) overexpression in head and neck cancer cell linesINTERNATIONAL JOURNAL OF CANCER, Issue 5 2003Seok-Woo Park Abstract The overexpression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) has been previously reported in head and neck squamous cell carcinoma (HNSCC), as well as in many cancers. We hypothesized that endogenous nitric oxide (NO) might increase the expression of COX-2 in cancer cells. Therefore, we investigated the cross-talk between NO and the prostaglandin (PG) pathways in HNSCC cell lines. We found that COX-2 and iNOS expressions were elevated simultaneously. On adding the NO donor, SNAP, the PGE2 level was increased 2,20 times due to increased COX-2 expression. This increase of COX-2 expression by SNAP or PMA (potent inducer of both iNOS and COX-2) was blocked to various degrees by NO scavengers and NOS inhibitors (L-NAME and 1400W). Also, the expression of COX-2 in resting cells was inhibited by NOS inhibitors. Moreover, COX-2 expression, induced by SNAP, was inhibited by ODQ, a soluble guanylate cyclase (sGC) inhibitor. The effect of dibutyryl-cGMP on COX-2 expression was similar to that of SNAP. These results imply that endogenous or exogenous NO activates sGC and that the resulting increase of cGMP induces a signaling that upregulates the expression of COX-2 in HNSCC cell lines. We also observed that NO increased COX-2 expression in different cancer cell lines, including cervic and gastric cancer cell lines. These findings further support the notion that NO can be associated with carcinogenesis through the upregulation of COX-2, and that NOS inhibitor may be also useful for cancer prevention. © 2003 Wiley-Liss, Inc. [source] The four mammalian splice variants encoded by the p21-activated kinase 3 gene have different biological propertiesJOURNAL OF NEUROCHEMISTRY, Issue 3 2008Patricia Kreis Abstract The p21-activated kinases (PAK1), PAK2, and PAK3 are members of the PAK group I and share high sequence identity and common biochemical properties. PAK3 is specifically implicated in neuronal plasticity and also regulates cell cycle progression, neuronal migration, and apoptosis. Loss of function of PAK3 is responsible for X-linked non-syndromic mental retardation whereas gain of PAK3 function is associated with cancer. To understand the functional specificities of PAK3, we analyzed the structure of PAK3 gene products. We report here the characterization of a new alternatively spliced exon called c located upstream of the previously identified exon b. Exon b is detected in all tetrapods and not in fish, exon c is only present in mammals. Mammalian PAK3 genes encode four splice variants and the corresponding proteins were detected with specific antibodies in brain extracts. All PAK3 transcripts are specifically expressed in brain and in particular in neurons. The presence of the exons b and c renders the kinase constitutively active and decreases interaction with GTPases. The expression of the new splice variants in COS7 cells alters cell morphology and modifies the structure of focal adhesions. We propose that the appearance of new alternatively spliced exons during evolution and the resulting increase of complexity of PAK3 gene products may confer new functions to this kinase and contribute to its specific roles in neuronal signaling. [source] Mechanism of foaming on polymer-paperboard compositesAICHE JOURNAL, Issue 2 2008S. Kiran Annapragada Abstract Foamed paperboard is a composite material with applications in the consumer products industry. The composite is comprised of paperboard sandwiched between two layers of polymers. One layer foams upon heating while the other acts as a barrier layer. Foaming is caused by the vaporization of the small amount of moisture present in the board and the resulting increase in pressure. The mechanism of foaming was investigated with a combination of high-speed photography, scanning electron microscopy, and infrared thermography using foamed paperboard of different compositions prepared both in the laboratory and on a commercial machine. The surface uniformity of the paper was found to be the overriding paper-related property controlling bubble formation. © 2007 American Institute of Chemical Engineers AIChE J, 2008 [source] Choline kinase overexpression increases invasiveness and drug resistance of human breast cancer cellsNMR IN BIOMEDICINE, Issue 6 2010Tariq Shah Abstract A direct correlation exists between increased choline kinase (Chk) expression, and the resulting increase of phosphocholine levels, and histological tumor grade. To better understand the function of Chk and choline phospholipid metabolism in breast cancer we have stably overexpressed one of the two isoforms of Chk-, known to be upregulated in malignant cells, in non-invasive MCF-7 human breast cancer cells. Dynamic tracking of cell invasion and cell metabolism were studied with a magnetic resonance (MR) compatible cell perfusion assay. The MR based invasion assay demonstrated that MCF-7 cells overexpressing Chk-, (MCF-7-Chk) exhibited an increase of invasion relative to control MCF-7 cells (0.84 vs 0.3). Proton MR spectroscopy studies showed significantly higher phosphocholine and elevated triglyceride signals in Chk overexpressing clones compared to control cells. A test of drug resistance in MCF-7-Chk cells revealed that these cells had an increased resistance to 5-fluorouracil and higher expression of thymidylate synthase compared to control MCF-7 cells. To further characterize increased drug resistance in these cells, we performed rhodamine-123 efflux studies to evaluate drug efflux pumps. MCF-7-Chk cells effluxed twice as much rhodamine-123 compared to MCF-7 cells. Chk-, overexpression resulted in MCF-7 human breast cancer cells acquiring an increasingly aggressive phenotype, supporting the role of Chk-, in mediating invasion and drug resistance, and the use of phosphocholine as a biomarker of aggressive breast cancers. Copyright © 2010 John Wiley & Sons, Ltd. [source] Pilot-scale demonstration of in situ capping of PCB-containing sediments in the lower Grasse RiverREMEDIATION, Issue 1 2003James D. Quadrini A fish-consumption advisory is currently in effect in a seven-mile stretch of the Grasse River in Massena, New York, due to elevated levels of PCBs in fish tissue. One remedial approach that is being evaluated to reduce the PCB levels in fish from the river is in situ capping. An in-river pilot study was conducted in the summer of 2001 to assess the feasibility of capping PCB-containing sediments of the river. The study consisted of the construction of a subaqueous cap in a seven-acre portion of the river using various combinations of capping materials and placement techniques. Optimal results were achieved with a 1:1 sand/topsoil mix released from a clamshell bucket either just above or several feet below the water surface. A longer-term monitoring program of the capped area commenced in 2002. Results of this monitoring indicated: 1) the in-place cap has remained intact since installation; 2) no evidence of PCB migration into and through the cap; 3) groundwater advection through the cap is not an important PCB transport mechanism; and 4) macroinvertebrate colonization of the in-place cap is continuing. Additional follow-up monitoring in the spring of 2003 indicated that a significant portion of the cap and, in some cases, the underlying sediments had been disturbed in the period following the conclusion of the 2002 monitoring work. An analysis of river conditions in the spring of 2003 indicated that a significant ice jam had formed in the river directly over the capping pilot study area, and that the resulting increase in river velocities and turbulence in the area resulted in the movement of both cap materials and the underlying sediments. The pilot cap was not designed to address ice jam,related forces on the cap, as the occurrence of ice jams in this section of the river had not been known prior to the observations conducted in the spring of 2003. These findings will preclude implementation of the longer-term monitoring program that had been envisioned for the pilot study. The data collected immediately after cap construction in 2001 and through the first year of monitoring in 2002 serve as the basis for the conclusions presented in this article. It should be recognized that, based on the observation made in the spring of 2003, some of these conclusions are no longer valid for the pilot study area. The occurrence of ice jams in the lower Grasse River and their importance on sediments and PCBs within the system are currently under investigation. © 2003 Wiley Periodicals, Inc. [source] Verlustfaktor-Korrektur der Schalldämmung bei gefülltem ZiegelmauerwerkBAUPHYSIK, Issue 1 2010Martin Schneider M.Sc. Dipl.-Ing. (FH) Elastically wall junction; Experimental set-up; Internal damping; Rigidly wall junction Schall; Technische Regelwerke Sound protection and acoustics; Technical standards Abstract In einem gemeinsamen Forschungsvorhaben der Hochschule für Technik Stuttgart und des Fraunhofer-Instituts für Bauphysik wurden die akustischen Eigenschaften von mit Dämmstoffen gefüllten Lochziegeln systematisch untersucht. Hierbei zeigte sich, dass sich die gefüllten Steine in ihrem Verhalten nicht wesentlich von ungefüllten Ziegeln unterscheiden. Der wichtigste Unterschied besteht in einer größeren inneren Dämpfung und als Folge davon einer gegenüber gleichartigen ungefüllten Ziegeln um etwa 1 bis 2 dB erhöhten Schalldämmung. Auf Grundlage der Untersuchungsergebnisse wurde ein modifiziertes Verfahren zur Verlustfaktor-Korrektur der Schalldämmung von Hochlochziegel-Mauerwerk entwickelt, das für gefüllte und ungefüllte Steine gleichermaßen anwendbar ist. Loss factor correction for hollow bricks filled with insulation material. The acoustic properties of hollow bricks filled with insulation material were systematically investigated in a joint research project by the University of Applied Sciences in Stuttgart and the Fraunhofer Institute for Building Physics. The findings showed that the acoustic performance of filled bricks differs only slightly from that of non-filled bricks. The main difference is greater inner damping and a resulting increase in sound insulation of about 1 to 2 dB compared to non-filled bricks of the same type. Based on the results of the investigation a modified procedure for the loss factor correction of the sound insulation of vertically perforated hollow brick masonry was developed, which applies equally to filled as well as non-filled bricks. [source] Inhibition of angiotensin-converting enzyme protects endothelial cell against hypoxia/reoxygenation injuryBIOFACTORS, Issue 4 2000Noriko Fujita Abstract Cardiovascular tissue injury in ischemia/reperfusion has been shown to be prevented by angiotensin-converting enzyme (ACE) inhibitors. However, the mechanism on endothelial cells has not been assessed in detail. Cultured human aortic endothelial cells (HAEC) were exposed to hypoxia with or without reoxygenation. Hypoxia enhanced apoptosis along with the activation of caspase-3. Reoxygenation increased lactate dehydrogenase release time-dependently, along with an increase of intracellular oxygen radicals. ACE inhibitor quinaprilat and bradykinin significantly lessened apoptosis and lactate dehydrogenase release with these effects being diminished by a kinin B2 receptor antagonist and a nitric oxide synthase inhibitor. In conclusion, hypoxia activated the suicide pathway leading to apoptosis of HAEC by enhancing caspase-3 activity, while subsequent reoxygenation induced necrosis by enhancing oxygen radical production. Quinaprilat could ameliorate both apoptosis and necrosis through the upregulation of constitutive endothelial nitric oxide synthase via an increase of bradykinin, with the resulting increase of nitric oxide. [source] Water balance modelling of (Sub-)Arctic rivers and freshwater supply to the Barents Sea BasinPERMAFROST AND PERIGLACIAL PROCESSES, Issue 3 2005Eduard Koster Abstract Recently, changes in the freshwater supply by rivers to the Arctic Ocean have attracted a great deal of attention. However, quantitative assessments of changes in the annual and seasonal discharge regime of (Sub-)Arctic rivers resulting from climate change are still far from accurate. The sensitivity of discharge to potential changes in climate in two river catchments of intermediate size (104,105,km2), the Tana River in northern Fennoscandia and the Usa River in northern Russia, both draining into the Barents Sea Basin, was evaluated using a spatially distributed water balance model. The tentative results show that discharge amounts during peak flow might remain more or less the same or show a slight increase. However, peakflow events are expected to occur about 20 days or more earlier in spring. Concerning annual discharge amounts a strong increase of 25% for the Usa River and even 39% for the Tana River is simulated in conformity with projected increases in precipitation. Obviously, the resulting increases of the annual freshwater influx from the Tana River (from 5.3 to 7.3,km3) and that of the Usa River (from 42 to 52,km3) into the Barents Sea are insignificant in absolute terms. But in relative terms they agree remarkably well with earlier estimates of changes in freshwater inflow by the very large (Sub-)Arctic rivers. Copyright © 2005 John Wiley & Sons, Ltd. [source] Interactive effects of increased temperature and CO2 on the growth of Quercus myrsinaefolia saplingsPLANT CELL & ENVIRONMENT, Issue 10 2001T. Usami Abstract The interactive effects of increased temperature and CO2 enrichment on the growth of 2-year-old saplings of Quercus myrsinaefolia, an evergreen broad-leaved oak, were studied throughout an entire year in the vicinity of their northernmost distribution. Saplings were grown under different conditions in two chambers: (1) a temperature gradient chamber at ambient temperature, 3 and 5 °C warmer conditions with an ambient CO2 concentration, and (2) in a CO2 temperature gradient chamber at 3 °C warmer conditions with 1·5 times the normal CO2 concentration, and 5 °C warmer conditions with doubled CO2 concentration. The 3 and 5 °C warmer conditions enhanced the relative growth rate during almost the entire year, producing 53 and 47% increases in annual biomass production, 27 and 44% enhancement of root growth during shoot dormancy and 3 and 5 week prolongation of the shoot growing period, respectively. However, a daily mean air temperature exceeding 30 °C under the 5 °C warmer condition caused a marked reduction in net assimilation rate (NAR) from July to September. The CO2 enrichment further enhanced the positive effects of warming in spring and the resulting increases in NAR almost completely compensated for the negative effect of warming during summer. From autumn to winter, attenuation of the effects of CO2 was compensated by the increased sink strength produced by the warming. The annual biomass production was more than doubled by the combination of temperature elevation and CO2 enrichment. [source] | ||||||||||||||||