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Lead-free piezoceramics based on the (Ba, Ca)(Zr, Ti)O3 (BCZT) system exhibit excellent electromechanical properties for low-temperature actuation applications, but suffer from relatively high processing temperatures. Here we demonstrate an approach for the reduction of the sintering temperature and simultaneous increase of the electromechanical strain response of (Ba, Ca)(Zr, Ti)O3 piezoceramics by aliovalent doping with Ce. The samples were prepared by solid state synthesis and their crystallographic structure, dielectric, ferroelectric, and electromechanical properties were investigated. The highest d*33 value of 1189 pm/V was obtained for the sample with 0.05 mol% Ce, substituted on the A-site of the perovskite lattice. The results indicate a large potential of these materials for off-resonance piezoelectric actuators.

International audience; Mineralogical compositions and grain-size distributions combined with 87Sr/86Sr and εNd values of the detrital fraction were studied on cores recovered from the Gulf of Aden (MD92-1002) and the Red Sea (MD92-1008) basins in order to document past changes in Indian monsoon and northwesterly winds during the last glacial-interglacial transition (the last 20 ka), encompassing the African Humid Period (AHP). The εNd vs. 87Sr/86Sr plot indicates that sediments result from the mixing of two main sedimentary sources corresponding to the Afar volcanic rocks in Ethiopia and to the Arabian-Nubian Shield. Variations of sediment isotopic and mineralogical composition point to a diminution of the volcanic source contribution during the last deglaciation. Changes of mineral-accumulation rates and grain-size distributions denote a decline in the aridity of the source regions during the Holocene, particularly of the Afar volcanic region. In this area, the reduction of detrital supply, from 15 cal ka BP, can be explained by an increase of precipitations during the AHP, which resulted in an expansion of the vegetation cover and lake extensions in East Africa. In the Arabian Peninsula, precipitations were confined to the south, allowing sediments to be transported even during the Holocene. Our data suggest that the southwest monsoon was not the main carrier of aeolian sediments to the Red Sea and Gulf of Aden basins, but the Northwesterlies. In the Red Sea, the isotopic and mineralogical tracers reveal a contribution from Saharan dust between 16 and 12 cal ka BP, transported from the Nile catchment after aridification during Heinrich event 1.

The Ediacaran-Cambrian transition is marked by the diversification of metazoans in the marine realm. However, this is not recorded by the Ediacaran-Cambrian Bambuí Group of the São Francisco basin, Brazil. Containing the sedimentary record of a partially confined foreland basin system, the Bambuí strata bear rare metazoan remnants and a major carbon isotope positive excursion decoupled from the global record. This has been explained by changes in the paleogeography of the basin, which became a restricted epicontinental sea in the core of the Gondwana supercontinent, promoting episodes of shallow water anoxia. Here, we report new δ15Nbulk data from the two lowermost second-order transgressive-regressive sequences of the Bambuí Group. The results show a rise of δ15N values from +2 to +5‰ in the transgressive system tract of the basal sequence, which was deposited when the basin was connected to other marginal seas. Such excursion is interpreted as an oxygenation event in the Bambuí sea. Above, in the regressive systems tract, δ15N values vary from +2 to +5‰, pointing to instabilities in the N-cyle that are concomitant with the onset of basin restrictions, higher sedimentary supply/accommodation ratios, and the episodic anoxia. In the transgressive systems tract, the δ15N values stabilise at ∼+3.5‰, pointing to the establishment of an appreciable nitrate pool in shallow waters in spite of the basin full restriction as marked by the onset of a positive carbon isotope excursion. In sum, our data show that the N-cycle and its fluctuations were associated with variations in sedimentary supply/accommodation ratios induced by tectonically-related paleogeographic changes. The instability of the N-cycle and redox conditions plus the scarcity of nitrate along regression episodes might have hindered the development of early benthic metazoans within the Bambuí seawater and probably within other epicontinental seas during the late Ediacaran-Cambrian transition.

When employed appropriately, ferroelectric materials present themselves as one of the most efficient means of waste (thermal/mechanical) energy scavenging. A large conversion potential can be obtained when appropriate materials are combined with high-field actuation (Ericsson cycle). However, waste energy rarely presents itself in an isolated form (heat or vibration). There is also a distinct lack of systems capable of simultaneous thermomechanical energy conversion, especially in the low-frequency range. In this regard a systematic approach to the concept of combined energy harvesting and storage potential of a singular material system is presented. Polarization versus electric field hysteresis loops were gathered as a function of temperature, uniaxial compressive stress, and electric field. Thereafter, a theoretical assessment was made to the effect of the biased and unbiased energy conversion potential of 0.50Ba(Zr0.2Ti0.8)O3– 0.50(Ba0.7Ca0.3)TiO3 bulk lead-free ferroelectric material. Maximum energy conversion potentials of 150 and 210 kJm@3 were obtained for thermal (5 MPa, 24–96 8C) and mechanical cycles (24 8C, 5–160 MPa), respectively. A slightly improved performance of 220 kJm@3 was obtained under simultaneous depolarization, despite performance degradation through individual biasing. However, the energy-storage density improved by 100% (80 kJm@3) and 50% (60 kJm@3), respectively, when operated under elevated stress (60 MPa) and temperature (90 8C). Results are indicative of a singular material system that could be used for combined thermomechanical energy conversion and on-board storage capacity.

© 2017 The American Ceramic Society Surface chemistry and topo-physical properties determine the interactions of biomaterials with their physiological environment. Ferroelectrics hold great promise as the next generation of scaffolds for tissue repair since they feature tunable surface electrical charges, piezoelectricity, and sensing capabilities. We investigate the topography, wettability, chemical stability, and cytotoxicity in salient ferroelectric systems such as (1−x) (Na1/2Bi1/2)TiO3–xBaTiO3, (1−x)Ba(Zr0.2Ti0.8)O3−x(Ba0.7Ca0.3)TiO3, and Pb(Zr,Ti)O3 to test their suitability as biomaterials. The lead-free ferroelectrics promote in vitro cell viability and proliferation to a considerably high extent. 0.94 mol % (Na1/2Bi1/2)TiO3–0.06 mol% BaTiO3 showed the greatest potential leading to a cell viability of (149 ± 30)% and DNA synthesis of (299 ± 85)% in comparison to the reference. Lead leaching from Pb(Zr,Ti)O3 negatively affected the cultured cells. Wettability and chemical stability are key factors that determine the cytotoxicity of ferroelectrics. These variables have to be considered in the design of novel electroactive scaffolds based on ferroelectric ceramics.

Lead-free Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-0.5BCT) ceramics have drawn attention in recent years because of their outstanding dielectric and electromechanical properties, such as a piezoelectric coefficient d33 ∼ 620 pC N−1 and a large signal of d 33 * ∼ 1100 pm V−1 at 0.5 kV mm−1 at room temperature (RT). These particular properties are relevant to a range of applications. However, the structural origin of this high piezoelectric coefficient is still a subject of discussion. An in-depth understanding of the ferroelectric domain evolution of BZT-0.5BCT ceramics is crucial for probing the underlying mechanisms and for guiding practical applications. Using piezoresponse force microscopy (PFM), we have directly visualized the evolution of the BZT-0.5BCT domain structure using temperature and electric field stimulation on micrometer and nanometer scales. The PFM results unambiguously evidence the coexistence of wedge-shaped and lamellar domains with miniaturized nanodomain structures at RT. The temperature- and electric-field-dependent PFM study presented here highlights the critical role of wedge-shaped domains in domain evolution. Wedge-shaped domains turn into small domains with curved domain walls after the heating cycle and then become lamellar domains after the poling cycle at RT. Transitional domain structures with an increased density of nanodomains appear in both the thermal and poling cycles. More interestingly, the electric-field-dependent domain structure evolution at different temperatures shows better domain structure reversibility at high temperatures than at temperatures close to the phase boundary. This demonstrates that the BZT-0.5BCT ceramic has superior stability at medium temperatures (40 °C–60 °C), implying excellent stability for applications.

Lead-free Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) piezoceramics with Bi2O3 additive were synthesized using solid-state ceramic processing. Various amounts of Bi2O3 (0.05, 0.1, 0.5, and 1.0 mol%) were added after calcination, milled, compacted, and sintered with no compensation at A- or B-sites. Addition of up to 0.5 mol% Bi2O3 was found to greatly enhance the densification and increase the piezoelectric properties, while higher amounts decreased the grain size and induced relaxor-like electrical behavior, obeying the Vogel-Fulcher model. The highest properties were obtained for the BCZT with 0.1 mol% Bi2O3 sintered at 1350 °C: d33 = 325 pC/m, d33* = 509 pm/V (at 3 kV/mm), kp = 0.42, and Pr = 10.4 μC/cm2. The microstructure, phase composition, and local structure were investigated by scanning electron microscopy, X-ray diffraction, and Raman spectroscopy. The appearance of the A1g vibration mode in the Raman spectra and the shift of diffraction peaks to lower 2θ values indicate the incorporation of Bi3+ into the B-site of the perovskite BCZT structure.

International audience; Clay mineralogy, siliciclastic grain-size, major elements, 87Sr/86Sr, and εNd analyses of deep-sea sediments cored in the north-eastern Bay of Bengal are used to reconstruct evolution of detrital sources and sediment transport to the proximal part of the Bengal deep-sea fan during the last climatic cycle. εNd values (−13.3 to −9.7) and 87Sr/86Sr ratios (0.721–0.733) indicate a mixture of sediments originating from the Ganges-Brahmaputra rivers and the Indo-Burman ranges. Interglacial Marine Isotopic Stages (MIS) 5 and 1 are associated with a higher contribution of sediments from the Ganges-Brahmaputra river system than is the case for glacial MIS 6, 4, 3, and 2. Siliciclasitic grain-size combined with Si/Al and Si/Fe ratios indicate coarser glacial sediments with numerous turbidite layers. Glacial turbidite layers display similar clay mineralogical compositions to hemipelagic sediments. Only few of turbidite layers (MIS 6, 4, and 2) are slightly unradiogenic (εNd −13.3), suggesting a higher contribution of Ganges-Brahmaputra river sediments. Independently of changes in the sedimentary sources, the smectite/(illite + chlorite) ratio of cores located on the NE Bengal Fan indicates higher inputs of primary minerals (illite and chlorite) from the highlands of the river basins (relief) during glacial MIS 6, 4, 3, and 2 and an increased contribution of pedogenic minerals (smectite and kaolinite) during interglacial MIS 5 and 1. Maximum smectite/(illite + chlorite) ratios during the warm sub-stages of MIS 5 suggest an intensification of summer monsoon rainfall associated with higher rates of physical erosion of the Indo-Gangetic flood-plain and/or dominant summer hydrological conditions transporting a higher proportion of sediments deriving from the Ganges-Brahmaputra rivers to the NE Bengal Fan. In addition, a higher production of smectite in soils of the Indo-Gangetic flood-plain during periods of intensification of monsoon rainfall cannot be excluded.

The Bi1/2Na1/2TiO3-based materials exhibit the largest electric-field-induced strains among lead-free piezoceramics and are considered as promising candidates for actuation applications. A typical representative of this group is (1-x)Bi1/2Na1/2TiO3-xSrTiO3, where its excellent electromechanical properties were recently related to the existence of a core–shell microstructure. Although the latter was also reported in other Bi1/2Na1/2TiO3-based ceramics, the formation mechanism remains unknown. In the present work we therefore first investigated the solid-state reaction occurring during calcination using simultaneous thermogravimetric analysis, X-ray diffraction, scanning and transmission electron microscopy. The reaction occurred in two steps, whereby the cores and shells had different formation reaction temperatures, which resulted in a metastable heterogeneous microstructure. Furthermore, a series of sintered samples with different relative densities, grain sizes, and core densities was prepared. Modifications of these microstructural parameters resulted in variation of the maximal strain by 17% and in the electric-field required to trigger the phase transitions by 38%.

Contiene además supplementary material.-- This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited., We have developed a wine fermentation procedure that takes advantage of the metabolic features of a previously characterized Metschnikowia pulcherrima strain in order to reduce ethanol production. It involves the use of M. pulcherrima/Saccharomyces cerevisiae mixed cultures, controlled oxygenation conditions during the first 48 h of fermentation, and anaerobic conditions thereafter. The influence of different oxygenation regimes and initial inoculum composition on yeast physiology and final ethanol content was studied. The impact of oxygenation on yeast physiology goes beyond the first aerated step and influences yields and survival rates during the anaerobic stage. The activity of M. pulcherrima in mixed oxygenated cultures resulted in a clear reduction in ethanol yield, as compared to S. cerevisiae. Despite relatively low initial cell numbers, S. cerevisiae always predominated in mixed cultures by the end of the fermentation process. Strain replacement was faster under low oxygenation levels. M. pulcherrima confers an additional advantage in terms of dissolved oxygen, which drops to zero after a few hours of culture, even under highly aerated conditions, and this holds true for mixed cultures. Alcohol reduction values about 3.7 % (v/v) were obtained for mixed cultures under high aeration, but they were associated to unacceptable volatile acidity levels. In contrast, under optimized conditions, only 0.35 g/L acetic acid was produced, for an alcohol reduction of 2.2 % (v/v), and almost null dissolved oxygen during the process., Authors would like to thank Cristina Juez Ojeda andMiguel Ángel Fernández Recio for excellent technical assistance, the YeSVitE consortium (EU project, 7FP-IRSES-GA no. 612441) for helpful discussions, and Laura López Ocaña (CECT) for help with yeast species confirmation. This work was supported by grants MINECO AGL2012-32064 and INIA RM2012-00007-00-00 from the Spanish Government. M.Q. was the recipient of a CSIC training contract, JAEDoc, co-funded by the European Social Fund of the EU.

This is an open access article under the CC BY-NC-ND license., Respiration of sugars by non-Saccharomyces yeasts has been recently proposed for lowering alcohol levels in wine. Development of industrial fermentation processes based on such an approach requires, amongst other steps, the identification of yeast strains which are able to grow and respire under the relatively harsh conditions found in grape must. This work describes the characterization of a collection of non-Saccharomyces yeast strains in order to identify candidate yeast strains for this specific application. It involved the estimation of respiratory quotient (RQ) values under aerated conditions, at low pH and high sugar concentrations, calculation of yields of ethanol and other relevant metabolites, and characterization of growth responses to the main stress factors found during the first stages of alcoholic fermentation. Physiological features of some strains of Metschnikowia pulcherrima or two species of Kluyveromyces, suggest they are suitable for lowering ethanol yields by respiration. The unsuitability of Saccharomyces cerevisiae strains for this purpose was not due to ethanol yields (under aerated conditions they are low enough for a significant reduction in final ethanol content), but to the high acetic acid yields under these growth conditions. According to results from controlled aeration fermentations with one strain of M. pulcherrima, design of an aeration regime allowing for lowering ethanol yields though preserving grape must components from excessive oxidation, would be conceivable., This work was funded by the AGL2012-32064 and RM2012-00007-00-00 projects from the Spanish Government. M.Q. was the recipient of a CSIC training JAE-Doc contract, co-funded by the European Social Fund of the EU.

The affiliation of author “Raziye HAYATI” in the original version of this article was unfortunately wrongly written on page 186, instead of Semiconductor Division, Materials and Energy Research Center, Karaj 31787/316, Iran It should read Department of Materials Engineering, Yasouj University, Yasouj, 75918-74934, Iran

© 2017 The American Ceramic Society The lead-free (1−x)Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 system is considered as promising candidate for the replacement of lead-based piezoceramics in actuation applications, during which electric fatigue is a major concern. This issue was addressed in this work, where the unipolar fatigue resistance of three (1−x)Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 compositions with different crystallographic structures (rhombohedral, orthorhombic, and tetragonal) was evaluated. Strain asymmetry and development of an internal bias field were observed in all compositions. The decrease in the remanent polarization and the large signal piezoelectric coefficient after 107 unipolar cycles was found to lie between 6%-12% and 2%-13%, respectively. The most pronounced fatigue was observed for the orthorhombic composition, which has the largest extrinsic contribution to strain. On the other hand, the best fatigue resistance was observed for the tetragonal composition, which has a predominantly intrinsic strain response. The correlation of fatigue resistance with strain mechanism was corroborated with determination of the Rayleigh parameters and changes in the domain morphology after cycling as confirmed by piezoresponse force microscopy.

Gas hydrates attracted intense research interest when it was first recognised some 70 years ago that they were responsible for the blockage of flow lines, valves and well heads, thereby causing great loss of production and other severe safety hazards to the oil and gas industry. After many decades, these compounds are still the topic of research activities in various multi-disciplinary fields, including chemical and petroleum engineering, earth and geophysics, chemistry and environmental sciences. This is not only due to the great impact that these compounds have on the oil and gas industry, but also to the potential applications they have in many evolving areas, including, but not only, natural gas storage and transportation, carbon dioxide sequestration, and sea-water desalination. It is generally accepted that gas hydrates represent the largest source of hydrocarbons on earth, something which has not been appreciated until only recently. Management, either prevention or application or both, of gas hydrates requires a complete knowledge and understanding of the formation, decomposition and inhibition mechanisms of gas hydrates, which in turn demands advanced experimental methods and instrumental techniques for gas hydrate characterisation. This paper reviews a broad range of techniques that have been used for natural gas hydrate characterisation. It includes the basic physical science principles of each method and the gas hydrate properties that each method is capable of detecting, including some modern instrumental analyses that enable direct determination of gas hydrate phases and possible measurement of molecular interactions within the fluid phases. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.

The adsorption of poly(N-vinylcaprolactam/N-vinylpyrrolidone/N,N-dimethylaminoethyl methacrylate), a commercial product with the trade name of Gaffix® VC-713 and currently used as a kinetic inhibitor for natural gas hydrates, has been experimentally studied at the air–liquid interface using surface tension measurements. The influence of polymer concentration and temperature on the adsorption of the polymer was analysed. The equilibrium experimental data obtained at both 293 K and 278 K has been fitted using the analogous surface equation of state for the Langmuir isotherm. Dynamic adsorption has been modelled using both diffusion-controlled and asymptotic models. The values of the surface tension and the surface excess at saturation showed that the polymer was very active at the air–liquid interface. Equilibrium surface tension indicated that temperature has a weak influence on the number of moles of Gaffix® VC-713 adsorbed on the interface. The dynamic adsorption was controlled by diffusion process initially, in which a rapid reduction in surface tension was observed. It was then followed by a slow polymer reorganization process. A strong dependence of the dynamic adsorption on both the temperature and the polymer concentrations was well demonstrated.

The macroscopic electromechanical behavior of lead-free bilayer composites was characterized at room temperature. One layer consisted of a nonergodic relaxor, (Bi1/2Na1/2)TiO3–7BaTiO3, with an electric-field-induced longrange ferroelectric order, whereas the other is understood to be an ergodic relaxor [(Bi1/2Na1/2)TiO3–25SrTiO3] that undergoes a reversible electric-field-induced macroscopic nonpolar-to-polar transition. Microstructural evidence of a bilayer with low diffusion between the two components is also demonstrated. By taking advantage of the different macroscopic strain– and polarization–electric-field responses of the two constituents, internal mechanical and electrical fields can be developed that enhance the unipolar strain over that expected by a rule of mixtures approximation, thereby improving the properties needed for application of such materials to actuator systems. It is possible through further tailoring of the volume fractions and macroscopic properties of the constituents to optimize the electromechanical properties of multilayer lead-free ferroelectrics.

Two non-Saccharomyces wine yeast strains, Hanseniaspora guilliermondii 11104 and Pichia anomala 10590, selected as good producers of acetate esters when grown on synthetic microbiological medium, have been tested in wine fermentations as mixed cultures together with Saccharomyces cerevisiae. Wines produced using mixed cultures showed levels of acetaldehyde, acetic acid, glycerol and total higher alcohols within the ranges described for wine, whereas an increase in acetate ester concentrations was found. Ethyl acetate was the main ester produced, and isoamyl acetate and 2-phenylethyl acetate made up the next largest group of ester compounds in the wines analysed. H. guilliermondii 11104 was found to be a strong producer of 2-phenylethyl acetate in both pure and mixed cultures whereas S. cerevisiae was the best producer of ethyl esters. Mixed cultures did not influence ethyl ester levels at all.

We present a critical review that encompasses the fundamentals and state-of-the-art knowledge of barium titanate-based piezoelectrics. First, the essential crystallography, thermodynamic relations, and concepts necessary to understand piezoelectricity and ferroelectricity in barium titanate are discussed. Strategies to optimize piezoelectric properties through microstructure control and chemical modification are also introduced. Thereafter, we systematically review the synthesis, microstructure, and phase diagrams of barium titanate-based piezoelectrics and provide a detailed compilation of their functional and mechanical properties. The most salient materials treated include the (Ba,Ca)(Zr,Ti)O3, (Ba,Ca)(Sn,Ti)O3, and (Ba,Ca)(Hf,Ti)O3 solid solution systems. The technological relevance of barium titanate-based piezoelectrics is also discussed and some potential market indicators are outlined. Finally, perspectives on productive lines of future research and promising areas for the applications of these ma...

A method has been developed for measurement in vitro of the simultaneous activities alcohol acetyltransferase (AATase) and ester hydrolase (EHase) in yeast extracts taking into account the possibility of interaction between the two opposite activities or the rapid inactivation of the AATase activity. A mathematical model, including as parameters a first order kinetic constant corresponding to the EHase activity and the inactivation constant of AATase, is proposed for the evaluation of AATase activity. To determine ester concentrations, the Headspace-SPME-GC technique has been used. The method has been successfully applied to three yeast strains belonging to the species Pichia anomala, Pichia heedii and Saccharomyces cerevisiae and the corresponding parameters for AATase and EHase have been calculated.

Replication-deficient lentiviral vectors (LV) have been shown to enable the stable genetic modification of multiple cell types in vivo. We demonstrate here that vascular and hepatic delivery of a third-generation HIV-derived lentiviral vector encoding human Factor IX (LV-hFIX) produced potentially therapeutic serum levels of hFIX protein with no vector-mediated local or systemic toxicity of adult mice. Portal vein administration produced the highest serum levels of hFIX and demonstrated proportionally higher levels of gene transfer to the liver with up to 4% of hepatocytes expressing hFIX. Vascular delivery of a lentiviral vector encoding GFP resulted in genetic modification of up to 12% of liver cells. Cell proliferation was not required for hepatocyte transduction with either vector. Serum hFIX levels reached 4% of normal levels following vascular LV-mediated hFIX gene transfer and remained stable for months following vector administration.

Summary β-D-glucosidase activity in 53 yeast strains belonging to the genera Candida, Dekkera, Hanseniaspora, Metschnikowia, Pichia, Rhodotorula, Schizosaccharomyces and Zygosaccharomyces, mainly isolated from grapes and wines, has been detected on the basis of its hydrolytic activity on 4-methylumbelliferyl-β-D-glucoside (MUG) and ρ-nitrophenyl-β-D-glucoside (pNPG). Only yeast species belonging to the genera Dekkera, Rhodotorula and Schizosaccharomyces did not produce the enzyme. The nine yeast strains demonstrating greatest β-D-glucosidase activity on pNPG at pH 3.5 in the presence of 10% (v/v) ethanol belong to the genera Candida, Hanseniaspora and Pichia and exhibited mainly cell wall bound activity. Anthocyanin-β-D-glucosidase activity was checked using an anthocyanin extract by following loss of absorbance at 520 nm. Whilst the nine yeast strains studied degraded the anthocyanin extract, H’spora osmophila 11207 and P. anomala 10590 were selected as the best producers of β-D-glucosidase with the lowest decolorizing activity.

The influence of the uniaxial preload on the off-resonance actuation performance of piezoelectric ceramics was investigated for compressive preload values up to −80 MPa. The study was performed on soft-type lead zirconate titanate (PZT), being the most widely used piezoelectric material. The samples were analysed using the proportional loading method, which enables the simultaneous application of electrical and mechanical loads, thereby mimicking the real operation conditions over the full stress–strain range. An increase of the blocking stress and the longitudinal piezoelectric stress coefficient was observed for all the applied preload values. The optimum properties, a blocking stress of −56 MPa and a free strain of 0.23%, were obtained at a preload value of −40 MPa and electric field of 2 kV mm − 1. This represents an increase of 16% and 20%, respectively, as compared to the values obtained at the smallest preload. In addition, the maximum work output was increased by about 28%. Finally, the results obtained at the lowest preload of −4 MPa using the proportional loading method were compared to the operational ranges determined by other methods. The comparison revealed large discrepancies between the methods, originating from the different order of the application of electrical and mechanical fields and the inherent nonlinearity of ferroelectric materials. This discrepancy results in decreased actuator performance due to impedance mismatching, demonstrating the need for accurate determination of the actuator's operational range.

Adenovirus has been used widely as a gene transfer vector in the laboratory and clinic for the purpose of gene therapy. Conditionally replication-competent oncolytic adenoviruses are capable of multiplying up to a thousand old in target cells, a property that might prove to be of tremendous potential in the area of cancer therapy. Intravesicular therapy of refractory superficial bladder cancer employing an oncolytic adenovirus would allow for local administration and efficient delivery of virus to bladder tumor. The glycosaminoglycan layer on the surface of the bladder urothelium acts as a nonspecific antiadherence barrier and may be a significant roadblock to efficient infection of the urothelium by adenoviruses. Several laboratories have investigated the potential utility of bladder pretreatment with chemical agents to enhance the adenovirus infection of bladder urothelium but with limited success. A class of compounds has been identified that is effective for pretreatment of urothelium, permitting efficient adenoviral infection. In a murine model, pretreatment of the bladder with 0.1% dodecyl-beta-D-maltoside (DDM) or sodium dodecyl sulfate (SDS) for 5 min resulted in >90% transduction of the urothelial layer within 15 min after exposure to a replication-defective adenovirus compared to

A double coupling bioreactor system was used to fast screen yeast strains for the production of acetate esters. Eleven yeast strains were used belonging to the genera Candida, Hanseniaspora, Metschnikowia, Pichia, Schizosaccharomyces and Zygosacharomyces, mainly isolated from grapes and wine, and two wine Saccharomyces cerevisiae strains. The acetate ester forming activities of yeast strains belonging to the genera Hanseniaspora (Hanseniaspora guilliermondii and H. uvarum) and Pichia (Pichia anomala) showed different substrate specificities and were able to produce ethyl acetate, geranyl acetate, isoamyl acetate and 2-phenylethyl acetate. The influence of aeration culture conditions on the formation of acetate esters by non-Saccharomyces wine yeast and S. cerevisiae was examined by growing the yeasts on synthetic microbiological medium. S. cerevisiae produced low levels of acetate esters when the cells were cultured under highly aeration conditions, while, under the same conditions, H. guilliermondii 11104 and P. anomala 10590 were found to be strong producers of 2-phenylethyl acetate and isoamyl acetate, respectively.

Cancer of the bladder is a good target for oncolytic virotherapy because the bladder has several unique features that allow for facile instillation of virus with minimal systemic exposure. CG8840 is a conditionally replication competent oncolytic adenovirus (OAV) designed to preferentially replicate and kill uroplakin II-positive bladder tumors. CG8840 replicates in and kills bladder transitional carcinoma cells (TCC) in vitro, with highly attenuated cytotoxicity in other cell types and human primary cells. In vivo, CG8840 elicits reproducible and dose-dependent anti-tumor effects in subcutaneous human xenograft tumor models in nude mice. We have developed an orthotopic bladder tumor model in nude mice to closely mimic the location and behavior of bladder tumors in humans. Employing the human bladder transitional cell carcinoma cell line SW780 we established tumors on the luminal surface of the nude mice bladder. In order to visualize the tumor growth and anti-tumor effect following virus infection, the TCC cell line SW780 was stably transduced to express the luciferase gene product. The bladder lumen was initially seeded with 1 × 106 SW780-luc tumor cells in a volume of 100 μl after which the mouth of the urethra was closed with a purse string for 1hr to allow for tumor cell attachment to the bladder wall. Following IP injection of luciferin, the orthotopic tumors were visualized in vivo by luminescence imaging. Measurement of the photon counts emitted from the tumors following luciferin injection allowed us to monitor the growth of the orthotopic tumors. Within 2 weeks tumor size was large enough to initiate efficacy studies. Immuno-histochemical analyses of the orthotopic tumor-bearing bladder with human anti-cytokeratin staining confirmed the human origin of the tumors. Histologically the SW780-Luc orthotopic tumors closely resembled superficial bladder tumors in humans. The need for pretreatment with dodecyl-β-D-maltoside to enhance infectivity of bladder epithelium with adenovirus was demonstrated earlier employing a beta galactosidase-expressing non-replicative adenovirus (Ramesh et al., 2003). For efficient infection of orthotopic tumors with adenovirus similar pretreatment was found to be essential. Following intravesical instillations of the uroplakin-II positive bladder tumor-specific OAV CG8840 we studied the anti-tumor efficacy of the virus. Three doses of CG8840 (1 × 1010 vp/treatment weekly for 3 consecutive weeks) were efficacious in reducing the tumor burden. Similar antitumor activity was not observed following intravesical instillation of a non-bladder tumor specific OAV. Six weeks after the initiation of OAV treatment, immuno-histochemical examination of the bladder showed complete absence of tumor cells in CG8840-treated mice. This simplified technique consistently produced a high incidence of orthotopic tumors in mice. This will be a useful model to conduct intravesical anti-tumor efficacy studies of OAV or other viruses both as single agents and in combination with other therapeutic agents.