bluuebunny/crossref_metadata_2025 huggingface dataset:
Thulium Doped Phosphors Under VUV Excitation
Authors: Moine Bernard , Beauzamy Léna , Meltzer Richard S.
Published: February 2009

Development of highly efficient mercury free fluorescent lamps and plasma display panels has been a challenging task due to the need for a combination of phosphor properties that are difficult to obtain in a single material (high efficiency, short emission lifetime and weak sensitivity to aging process under VUV excitation). Quantum cutting mechanism is a way to improve the fluorescence efficacy. Here we describe quantum cutting involving pairs of Tm3+ ions in KY3F10. Efficient excitation in the vacuum UV is initiated to the 5d state of Tm3+. This is followed by a cross relaxation energy transfer (CRET) involving the excited ion in the 5d state and nearby Tm3+ in the ground state, producing a pair of Tm3+ in excited states of the 4f13 configuration. Both ions can then emit photons. The excitation and reflection spectra are studied as a function of Tm3+ concentration and temperature. An unusual enhancement of the reflectivity at excitation wavelengths corresponding to the Tm3+ 5d absorption peaks is shown to arise from strong 5d→4f emission which is confirmed from the VUV emission spectra. The strong reduction of the integrated 5d emission intensity and shortening of its lifetime with Tm3+ concentration indicates the effective presence of the desired CRET process that is required for the first step of the quantum cutting. High Tm3+ concentrations are required for efficient quantum cutting. Whereas the CRET from the 5d state is estimated to be quite efficient, the 4f13 states of Tm3+ also undergo a strong CRET and therefore, emission from the 4f13 excited states that are created from the first step are strongly quenched at high Tm3+ concentrations. As a result, quantum yields greater than unity are not achieved.
Influence of the Evolution of the Surface Area Value on the Spent Nuclear Fuel Dissolution Rate for Performance Assessment Studies
Authors: Quiñones Javier , Iglesias Eduardo , Rodriguez Nieves , Nieto Juan Manuel
Published: February 2009

This paper focuses on how to extrapolate current knowledge of spent fuel matrix alteration processes from laboratory to repository conditions, i.e., the influence of changes in both the initial surface oxidation level and the evolution of the specific surface area during the alteration process. Therefore, a spent fuel matrix alteration model allowing the alteration rate evolution to be predicted as a function of both the host rock considered and evaluation time scale of interest is described. At present, the model assumes that alteration of the spent fuel will start when the groundwater reaches the solid surface and that only the radiolytic species of the groundwater (oxidants generated by a-radiation of spent fuel) will produce the surface oxidation process and subsequent matrix dissolution; O2, H2O2 and OH are the species that react with UO2(s) for oxidation of the pellet surface. The dissolution process of the surface sites that are oxidized is modelled in two steps: first, a surface co-ordination of the oxidized layer with aqueous ligands and, second, detachment (dissolution) of the product species. Taking this mechanism into account, the model gives the evolution of the spent fuel matrix alteration rate over periods as long as 1,000,000 years. In this work is focussed on input the experimental results obtained of UO2 surface area behaviour (presented in previous MRS conference), on the MAM model. The matrix alteration rate results obtained, with MAM model, for repository granitic environment will be presented and compared to those performed for SFS project. Furthermore, a sensitivity analysis study has been performed on the influence of the following variables: Influence of the initial power size distribution and the initial oxidation state
A New Criterion for the Degradation of a Defective Spent Fuel Rod under Dry Storage Conditions Based on Nuclear Ceramic Cracking
Authors: Desgranges Lionel , Charollais François , Felines Isabelle , Ferry Cécile , Radwan Jean
Published: February 2009

Experimental results using environmental SEM on intentionally defected fuel particles showed that oxidation induced cracking could lead to the degradation of HTR coated particles. The interpretation proposed for the swelling resulting from cracking can be extended to irradiated nuclear fuels. That is why a new criterion was proposed to defined safe handling of defective fuel in dry storage condition. This criterion defines the time needed to create an oxidized layer thickness leading to significant cracking.
Electron Energy-loss Near-edge Structure of Zircon
Authors: Jiang Nan
Published: February 2009

This work demonstrates that absorption near-edge structures of the O K-edge in zircon are directly related to atom structure, including bond length, bond angle and coordination. Small variations in the structure can induce measurable changes in absorption spectrum.
HIPed Tailored Pyrochlore-Rich Glass-Ceramic Waste Forms for the Immobilization of Nuclear Waste
Authors: Carter Melody Lyn , Li Hui , Zhang Yingjie , Gillen Andrew L , Vance Eric R
Published: February 2009

Hot isostatically pressed (HIPed) glass-ceramics for the immobilization of uranium-rich intermediate-level wastes and Hanford K-basin sludges were designed. These were based on pyrochlore-structured Ca(1-x)U(1+y)Ti2O7in glass, together with minor crystalline phases. Detailed microstructural, diffraction and spectroscopic characterization of selected glass-ceramic samples has been performed, and chemical durability is adequate, as measured by both MCC-1 and PCT-B leach tests.
Identification of Oxygen-Depleting Components in MX-80 Bentonite
Authors: Carlsson Torbjörn , Muurinen Arto
Published: February 2009

After closure, the near-field of a nuclear waste repository contains large amounts of oxygen in tunnels and deposition holes. The bentonite buffer/backfill will contain oxygen as a gas phase in unsaturated pores as well as dissolved gas in porewater. The redox conditions in the bentonite filling after post-closure will change towards reducing conditions. In the initial stage, the development of the redox state is mainly governed by the depletion of oxygen. The main mechanisms of oxygen depletion in the bentonite are: 1) diffusion into the surrounding rock and 2) reactions with accessory minerals and by microbial aerobic consumption of organic matter [1,2]. The reactions leading to oxygen depletion are not, however, well understood. The objective of this work was to gather new information concerning oxygen depletion in MX-80. This was done by measuring oxygen depletion and changes in the redox state in suspensions of 1) MX-80, 2) a heavy fraction of MX-80, or 3) a light fraction of MX-80.
Soft X-ray Spectroscopic Characterization of Montmorillonite
Authors: Rubensson Jan-Erik , Hennies Franz , Werme Lars O , Karnland Ola
Published: February 2009

Soft X-ray spectroscopy was applied to study a calcium bentonite from the Kutch area in India. We recorded the X-ray absorption spectra from the L-edge of calcium, silicon, and aluminum, and from K-edge of oxygen. The Ca absorption spectrum shows a quasi-atomic behavior, while the Si spectrum closely simulates the absorption spectrum of a pure silicon oxide. The O K spectrum shows a pre-peak, which is absent in the spectra of both the pure, bulk aluminum and silicon oxides. The Al L spectrum is complex and shows almost no resemblance to the absorption spectrum of aluminum oxides. The chemical state of the Al atoms (in octahedral coordination) must, thus, be quite different from what is common in the oxides. The obtained data show that soft X-ray spectroscopy is a promising technique for studying clay minerals. It is capable of supplying unique information that is complementary to information accessible using other techniques; especially, it can be used to determine the local electronic structure at various atomic sites in the complex samples.
Experimental Study and Modeling of Uranium (VI) Sorption onto a Spanish Smectite
Authors: Missana Tiziana , Alonso Ursula , Garcia-Gutierrez Miguel , Albarran Nairoby , Lopez Trinidad
Published: February 2009

Adsorption of uranium onto a Spanish smectite was studied, analyzing the effects of the most important parameters such as pH, ionic strength, radionuclide concentration and solid to liquid ratio. Batch sorption studies, in anoxic conditions under N2 atmosphere, were carried out on the bentonite previously purified and converted into the homoionic Na-form.
In the sorption edges, two regions could be clearly distinguished. At pH lower than 5, sorption depended strongly on the ionic strength, possibly indicating the predominance of the uranyl ionic exchange process. At higher pH, sorption did not depend on the ionic strength but only on pH. The sorption behavior in this region suggested the predominance of a surface complexation mechanism. Sorption isotherms showed a non linear behavior in the concentration range used.
Sorption data were interpreted using a non electrostatic standard model combining surface complexation, with the weak and strong SOH sites of the clay, and ionic exchange. The acid – base properties of the weak SOH sites were determined by potentiometric titrations. The model used was able to reproduce, in a very satisfactory way, all the data in a wide range of experimental conditions.
General Corrosion Behavior of N06022 in Super Concentrated Brines at Temperatures Higher than 100°C
Authors: Rebak Raul B.
Published: February 2009

Alloy 22 (N06022) is a highly corrosion resistant nickel based alloy. Extensive research has been conducted in the last eight years on the corrosion behavior of Alloy 22, mainly regarding its resistance to localized corrosion. Less attention has been paid to the general corrosion resistance in highly concentrated brines that may result from the deliquescence of salts contained in dust. Salts such as mixtures of NaCl, KCl, CaCl2, NaNO3, and KNO3 may deliquesce at temperatures above 100°C through absorption of moisture from the air. Electrochemical tests were used to assess the general corrosion behavior of Alloy 22 in brines with chloride and nitrate concentrations ranging from 8 molal to 100 molal in the temperature range 100 to 160°C. The effect of mixed anions and cations was also studied. Results show that, even for short-term immersion periods, the corrosion rate of Alloy 22 in high temperatures super concentrated brines is generally below 10 μm/year.
Hydrogen Storage Properties, Metallographic Structures and Phase Transitions of Mg-based Alloys Prepared by Super Lamination Technique
Authors: Takeichi Nobuhiko , Tanaka Koji , Tanaka Hideaki , Kuriyama Nobuhiro , Ueda Tamotsu T , Tsukahara Makoto , Miyamura Hiroshi , Kikuchi Shiomi
Published: February 2009

We have prepared Mg/Pd laminate composites with (Mg/Pd)=6, 3 and 2.5 atom ratios, by a super lamination technique. The homogeneous Mg-Pd intermetallic compounds, Mg6Pd, Mg3Pd and Mg5Pd2, are formed during the initial activation process. We investigated the hydrogen storage properties of these materials. The compounds can reversibly absorb and desorb a large amount of hydrogen, up to 1.46˜0.9 H/M, at 573 K. Except for the Mg5Pd2-hydrogen system, the pressure composition-isotherms show two plateaux. The mechanism of the phase transition during hydrogenation/dehydrogenation was analyzed by in-situ XRD measurements. These intermetallic compounds absorb and desorb hydrogen through reversible multistage disproportionation and recombination processes.
Alloying Effect on Mechanical and Chemical Properties of Cold-rolled Ni3(Si,Ti) Foils
Authors: Fujimoto Y. , Kaneno Yasuyuki , Takasugi Takayuki
Published: February 2009

Four kinds of L12-type Ni3(Si,Ti) intermetallic alloys with a quaternary element X (X: Al, Cr, Co and Mo) were warm rolled accompanied by intermediate annealing and then cold rolled to thin foils. The effects of alloying element on microstructure, tensile properties and oxidation resistance of the cold-rolled Ni3(Si,Ti) foils were investigated. The Al-added Ni3(Si,Ti) alloy showed an L12 single-phase microstructure, while the Cr-, Co- and Mo-added Ni3(Si,Ti) alloys exhibited a two-phase microstructure consisting of L12 and fcc Ni solid solution phases. Room-temperature strength of the Ni3(Si,Ti) foils was slightly enhanced by the addition of quaternary element, whereas high-temperature strength was significantly enhanced especially by the addition of Mo and Co. High-temperature tensile elongation was remarkably improved by the addition of all the elements investigated. On the other hand, oxidation resistance was improved by the addition of Al and Cr.
Fracture and Fatigue of Niobium Silicide Alloys
Authors: Herman David M. , Bewlay Bernard P , Cretegny Laurent , DiDomizio Richard , Lewandowski John
Published: February 2009

The fracture and fatigue behavior of refractory metal silicide alloys/composites is significantly affected by the mechanical behavior of the refractory metal phase. This paper reviews some of the balance of properties obtained in the alloys/composites based on the Nb-Si system. Since some of the alloy/composite properties are dominated by the behavior of the refractory metal phase, the paper begins with a review of data on monolithic Nb and its alloys. This is followed by presentation of results obtained on Nb-Si alloys/composites and a comparison to behavior of some other high temperature systems.
Modeling of Microstructure Evolution in Nb-Si Eutectic Alloy Using Cellular Automaton Method
Authors: Ohsasa Kenichi , Miura Seiji
Published: February 2009

A numerical model was developed for the simulation of microstructure evolution during the solidification of Nb-Si eutectic alloy. In this model, the cellular automaton method was used to simulate the eutectic growth of Nb solid solution and Nb3Si intermetallics. Diffusion in liquid, mass conservation at the solid/liquid interface and local equilibrium at the solid/liquid interface with consideration of curvature undercooling were solved to determine the positions of the Nb/liquid and Nb3Si/liquid interfaces. In the alloy with eutectic composition of 0.18at%Nb, irregular eutectic growth morphology was observed in relatively lower undercooling region. On the other hand, in higher undercooling region over 50K, dendrite morphology of Nb3Si was observed. An alloy with hypo-eutectic composition, cell and dendrite morphology were observed in lower undercooling region, while coupling eutectic morphology was formed in higher undercooling region over 25K.The growth velocity of the coupling growth increased with increase in the degree of undercooling of melt.
High-temperature Deformation Kinetics of Gold at 473K to 773K
Authors: Bhakhri Vineet , Klassen Robert J.
Published: February 2009

High-temperature constant-force indentation creep tests of 200 seconds duration were performed on an annealed gold specimen at 473K to 773K, to investigate the dependence of the micro-/nano-indentation deformation kinetics upon indentation stress, temperature and time. The indent stress displayed a clear indentation size effect at 473 K. An analysis of the measured indentation creep rate, and its dependence upon temperature and stress, indicate that the strength of the deformation rate limiting obstacles increases with temperature. This is consistent with the expected temperature dependent evolution of the dislocation cell structure whose boundaries become the primary obstacles to dislocation glide.
The Role of Defects in Carbon Nanostructures Probed through Ion Implantation and Electrochemistry
Authors: Hoefer Mark , Nichols Jeffrey , Bandaru Prabhakar
Published: February 2009

As carbon nanotubes (CNTs) inevitably contain defects, an understanding of their effect on the electrochemical behavior is crucial. We consider, through Cyclic Voltammetry and Raman Spectroscopy, the influence of both intrinsic and extrinsically introduced defects. Bamboo and hollow multi-walled carbon nanotube morphologies provided examples of the former while the controlled addition of Argon and Hydrogen ions was used for studying extrinsic defects. We show that the electrocatalytic response of the hollow type CNTs can be tailored significantly, while bamboo type CNTs have innately high reactive site densities and are less amenable to modification. Argon irradiation also differs greatly from that of Hydrogen irradiation. CNT irradiation with Argon appears to positively charge CNTs, while Hydrogen irradiation neutralizes defects further allowing for the tuning of CNT defect density. The work has implications in the design of nanotube and nanowire based chemical sensors.
Effect of the powering frequency on the synthesis of carbon nanostructures by AC arc discharge at atmospheric pressure
Authors: Vittori Antisari Marco , Mirabile Gattia Daniele , Marazzi Renzo , Piscopiello Emanuela , Montone Amelia
Published: February 2009

In this paper we report about the synthesis of single wall carbon nanohorns and highly convoluted graphite sheets by AC powered arc discharge carried out between pure graphite electrodes. The arc is ignited in air and the arched electrodes are surrounded by a cylindrical collector which collects the synthesized material and contributes to control the synthesis environment. With the purpose of studying the effect of the process variables, in this work we have explored the effect of the powering frequency on the structure of the synthesized material and on the yield of the process. Preliminary experimental results on tests carried out at constant voltage, show that the process yield is strongly influenced by the powering frequency and that higher yields are obtained at low frequency. The structure of the resulting soot has been characterized by transmission electron microscopy. Two kinds of microstructures are found by TEM observation constituted by highly convoluted graphene sheets, having locally the nanohorn morphology, and better organized nano-balls where also graphite nano-sheets can be locally found. The relative abundance of the two kinds of particles appears to depend on the powering frequency with a larger amount of the latter observed in samples synthesized at high frequency.
Fabrication of Highly Porous Zinc and Zinc Oxide Nanostructures
Authors: LaForge Joshua Michael , Brett Michael J.
Published: February 2009

Glancing angle deposition (GLAD) is a physical vapor deposition technique that depends on a highly oblique flux angle to create porous, large surface area thin films via self-shadowing. Control of the deposition parameters may provide a means to tune film porosity for zinc oxide sensors and photovoltaic devices. However, the self-shadowing mechanism requires a collimated particle flux, and therefore GLAD performs best under high vacuum. Creating structured films with sputtered GLAD is difficult since the high chamber pressure (>1 mTorr) necessary to maintain the sputter plasma reduces the mean-free-path of flux particles to less than 100 mm. By using an aperture to reduce the angle subtended by the target from the perspective of the substrate, maintaining an argon plasma pressure of 1.4 mTorr, and reducing the throw distance to less than 50 mm we were able to produce structured, polycrystalline, zinc thin films via GLAD. At oblique flux angles, highly porous films consisting of randomly oriented nanorods are grown. The nanorods have diameters between 10-100 nanometers with lengths up to several micrometers. Annealing at temperatures up to 250 °C in air produces polycrystalline zinc oxide with minimal changes to the film structure. We present details of the thin film fabrication process for the convoluted nanorod film morphology. We report characterization results for films produced at several deposition angles before and after annealing using scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM).
Growth and survival of northern leopard frog (Rana pipiens) tadpoles exposed to two common pesticides
Authors: Shenoy Kausalya , Cunningham B. Thomas , Enfroe James W. R. , Crowley Philip H.
Published: February 2009

Aquatic pollution is an important factor implicated in global amphibian declines. Often amphibians are exposed to sublethal levels of agrochemicals continuously throughout their larval period either because of application regimes or persistence of the chemicals in the larvae's environment. Although most studies have examined the effects of one-time or short-term exposure to contaminants on amphibian larvae, few have investigated the implications of continuous exposure over a substantial interval during larval development. We examined the effects of continuous exposure to environmentally relevant concentrations of two common pesticides—endosulfan (0.2, 1, and 5 μg/L) and mancozeb (16, 80, and 400 μg/L)—on the growth and survival of leopard frog tadpoles. The concentrations used are comparable to those estimated to be found in waterbodies near agricultural fields. The exposure period was seven weeks. Mortality was recorded daily, and length was measured photographically once before and twice during the exposure period. Both chemicals greatly reduced survival at these concentrations. Hazard ratios were significantly positive for all treatments. Growth rates of tadpoles exposed to endosulfan were not significantly reduced, but exposure to all three levels of mancozeb resulted in reduced growth rates. These results underscore the importance of further investigation into the effects of endosulfan and mancozeb on environmental and wildlife health.
Sorption of nitroaromatics to soils: Comparison of the importance of soil organic matter versus clay
Authors: Zhang Dongmei , Zhu Dongqiang , Chen Wei
Published: February 2009

Nitroaromatic compounds are produced and used in large quantities worldwide and are frequently detected contaminants in the environment. Sorption is one of the fundamental processes controlling the transport and availability of nitroaromatics, but previous studies have focused mainly on sorption to model clay minerals, whereas little attention has been paid to the sorptive interactions with natural soils. Findings in this study show that soil organic matter (SOM) was the predominant soil component controlling sorption of 2,4-dinitrotoluene and nitrobenzene to three typical Chinese soils, and sorption to clay minerals was much less important. The weak sorption to clay minerals was due to the type of exchangeable cations of the soils, and after saturating the soil clay minerals with K+ and Cs+, sorption to clay minerals increased significantly. Compared with the apolar phenanthrene, 2,4-dinitrotoluene and nitrobenzene exhibited much higher nonhydrophobic affinity to SOM, likely because of the π-π electron donor-acceptor interaction between the nitroaromatic molecules and the aromatic structure of the SOM. Moreover, the polarity and aromaticity of SOM might also have important effects on sorption of nitroaromatics. Sorption of nitroaromatics to natural soils appears to be more complicated than sorption of apolar hydrophobic organic compounds, and this complexity should be taken into account in environmental management such as risk calculation and transport modeling.
Development of a New Polymer Inhibitor Chemistry for Downhole Squeeze Applications
Authors: Montgomerie Harry , Chen Ping , Hagen Thomas , Vikane Olav , Matheson Rozenn , Leirvik Vibeke , Frøytlog Cato , Sæten Jens Olav
Published: February 2009

Scale inhibitor squeeze treatments have regularly been conducted to prevent both sulphate and carbonate scale depositions in a specific North Sea field for more than 10 years. However, some wells, in which the fluid is producing from the "clean" sandstone formation, have experienced relatively short squeeze lives, when squeezing a conventional phosphonate scale inhibitor treatment. A research program has been conducted to develop a novel polymer scale inhibitor chemistry, which combines performance in a number of laboratory static and dynamic tests, with improved scale inhibitor adsorption properties on "clean" sandstone formations. Field trials have also been conducted with satisfactory results.

This paper outlines the concept of how novel scale inhibitor chemistry was developed by incorporating a special monomer to make the final copolymer scale inhibitor. The monomer was introduced to enhance the inhibitor adsorption properties, because it carries a special functional group to improve the scale inhibitor affinity for the reservoir rock. This special functional group plays a key role for the newly developed scale inhibitor, to give improved and acceptable squeeze lives. A critical aspect of the program included optimizing the monomer content to achieve a good adsorption/desorption balance, to ensure that the scale inhibitor would be desorbed/released from the reservoir rock to meet the requirements of an acceptable squeeze program. An added bonus was that the environmental properties of the scale inhibitor polymer were also improved because of the introduction of the special monomer. A number of beaker and dynamic loop tests were conducted and the inhibitor showed an excellent efficiency in both sulphate and carbonate scale inhibition performance tests under the test conditions adopted.

This paper also presents detailed laboratory and field data; the treatment design strategy and deployment method adopted for the scale inhibitor.
Predicting Influent Estradiol and Estrone Concentrations for Wastewater Treatment Facilities
Authors: Jarvie Michelle E. , Hand David W.
Published: February 2009

An externally validated model was developed to predict influent concentrations of natural estrogens at municipal wastewater plants. The model kinetic constant for the first‐order biotransformation of estradiol into estrone, k E2, was calculated as 0.030 hour −1 (ranging from −0.080 to 0.49 hour −1, with a standard deviation of 0.23) and the model value for the biodegradation k of estrone, k E1, was −0.18 hour −1(ranging from −0.44 to 0.38 hour −1, with a standard deviation of 0.3). The k values were not found to be temperature‐sensitive within the range 12 to 24.5°C and displayed a weak trend of increasing with total suspended solids within the range 0.103 to 0.450 g/L. The new model improved on the predictions of a previous model for influent estrone concentrations, but gave comparable results for estradiol.
Arsenite Oxidation by Immobilized Cells of Alcaligenes faecalis Strain O1201 in a Fluidized‐Bed Reactor
Authors: Wang Yi‐Tin , Suttigarn Arthon , Dastidar Aniruddha
Published: February 2009

Arsenic(III) oxidation was evaluated in a continuous‐flow fluidized‐bed reactor (FBR) with Alcaligenes faecalis strain O1201 immobilized in gel beads. The FBR was operated under 300 mg/L citrate and a range of influent As(III) concentrations (75 to 3000 mg/L) at short hydraulic retention times (1.06 to 3.17 hours). The pH and temperature in the FBR were maintained at optimal growth conditions for strain O1201 (pH 7 and 30°C) throughout the study. A total of 10 quasi‐steady‐state operating conditions were obtained after 54 days of operation under an As(III) concentration of 441 mg/L (10 000 mg/L/d loading rate), with As (III) removal efficiency ranging from 76% to near complete. Material balance analysis over the FBR revealed that the difference between the cumulative influent As (III) and the sum of cumulative effluent As(III) and As(V) was insignificant. The major mechanism of As(III) removal from the FBR is biological oxidation to As(V).
Altered Carbon Flow by Polyphosphate‐Accumulating Organisms During Enhanced Biological Phosphorus Removal
Authors: Ahn Chang Hoon , Park Jae Kwang , Whang Liang‐Ming
Published: February 2009

The effect of carbon source availability during enhanced biological phosphorus removal (EBPR) was evaluated. To assess the EBPR activity of polyphosphate‐accumulating organisms (PAOs), PAO‐enriched sludge from a laboratory‐scale sequencing batch reactor and activated sludge from a full‐scale municipal wastewater treatment plant were used, and their EBRP performances were compared. Spiking with acetate (1000 mg/L chemical oxygen demand) during the aerobic phase disrupted the EBPR performance of both types of sludge; however, when the carbon source was removed, still in the aerobic phase, the EBPR performance of both types of sludge was restored. The PAO‐enriched sludge showed 3 to 5 times greater glycogen restoration activity per biomass than the full‐scale activated sludge. During high acetate loading in the anaerobic phase, PAOs are supposed to deplete internally stored polyphosphate, causing a “poly‐phosphate limited condition”. Under such a condition, unlike the full‐scale activated sludge, the PAO‐enriched sludge produced a higher fraction of poly‐hydroxylvalerate. It was proposed that PAOs can use the glyoxylate pathway and the methymalonyl‐CoA pathway through a full or partial tricarboxylic acid cycle under the anaerobic condition.
Benthic Macroinvertebrate Susceptibility to Trout Farm Effluents
Authors: Roberts Lenn , Boardman Gregory , Voshell Reese
Published: February 2009

The direct effects of a Virginia trout farm on benthic macroinvertebrates were examined using multiple approaches. Static laboratory tests with the amphipod, Hyallela azteca, were conducted with exposures to water taken from a spring and from effluent both above and below a sedimentation basin. Onsite mesocosms were constructed to expose previously colonized artificial substrates to the same treatments as the laboratory tests. Flat‐headed mayflies also were collected from a nearby stream and transported to the mesocosms for a 10‐d exposure. There was no significant difference between treatments in the laboratory tests after 20 d, but after 28 d the control was significantly lower than the above‐sedimentation basin treatment in one test. In the multispecies field tests, a clear decrease in total invertebrate and Ephemeroptera, Plecoptera, and Trichoptera (EPT) abundance was seen in the effluent treatments compared to spring water treatments. There was, however, a slight improvement in survival in treatment below the sedimentation basin. Only total invertebrate abundance after 21 d produced statistically significant differences. A significant difference was detected between the effluent and the spring treatments in the flat‐headed mayfly field test. We suggest that in this study, the effluent alone does not explain the lack of taxa richness in the receiving stream. The main cause of mortality from trout effluents appears to be solids accumulating upon the organisms. Well operated and designed sedimentation basins are expected to, in part, reduce any effects on macroinvertebrates.
Investigation of Antihyperglycemic Activity of Glycine max (L.) Merr. on Serum Glucose Level in Diabetic Mice
Authors: Badole Sachin L. , Bodhankar Subhash L.
Published: February 2009

Glycine max (Soybean) is being used as fresh, fermented or dried food. Petroleum ether (GM-PEE), alcoholic (GM-ALE) and aqueous extract (GM-AQE) of seeds of Glycine max were prepared and evaluated for antihyperglycemic activity. GM-PEE (100 mg/kg), GM-ALE (100 mg/kg, p.o.), GM-AQE (100, 200 and 400 mg/kg, p.o) and glyburide (10 mg/kg, p.o) were administered orally in alloxan-induced(80 mg/kg, i.v.) diabetic mice. Serum glucose level was estimated after acute and chronic treatment with extracts. Oral glucose tolerance test (OGTT) was performed in GM-AQE pretreated animals. GM-PEE (100 mg/kg) and GM-EE (100 mg/kg) did not reduce serum glucose level. GM-AQE (100, 200 and 400 mg/kg) significantly reduced serum glucose level (antihyperglycemic effect) in acute and chronic studies. The antihyperglycemic effect of GM-AQE (100, 200 and 400 mg/kg) showed onset at the 2nd h; peak effect at the 4th h and the antihyperglycemic effect was sustained till the 24th h. In chronic study, reduction in serum glucose level was observed on the 28th day and also after withdrawal for next 7 days. In OGTT, increased glucose tolerance was observed in GM-AQE (100 and 200 mg/kg) treated non-diabetic as well as diabetic mice. It is concluded that GM-AQE but not GM-PEE and GM-ALE showed antihyperglycemic activity.
Kainic acid lesion-induced spatial memory deficits of rats
Authors: Hritcu Lucian , Nabeshima Toshitaka
Published: February 2009

The effects of lesioning the ventral tegmental area (VTA) or substantia nigra (SN) neurons by means of bilateral stereotaxic microinjections of kainic acid (KA) (0.4 mM) were investigated to clarify the role of the VTA and the SN neurons in learning and memory processes. The present study demonstrates that KA in the SN and the VTA lesioned rats significantly decreased spontaneous alternation in Y-maze task, working memory and reference memory in radial 8 arm-maze task, suggesting effects on spatial memory performance. Our findings provide further support for the role of the VTA and the SN neurons in processing and storage of information.
Hydrogen peroxide-induced response in E. coli and S. cerevisiae: different stages of the flow of the genetic information
Authors: Semchyshyn Halyna
Published: February 2009

Adaptation to oxidative stress is a major topic in basic and applied research. Cell response to stressful changes is realized through coordinated reorganization of gene expression. E. coli and S. cerevisiae are extremely amenable to genetic or molecular biological and biochemical approaches, which make these microorganisms suitable models to study stress response at a molecular level in prokaryotes and eukaryotes, respectively. The main focus of this review is (i) to discuss transcriptional control of global response to hydrogen peroxide in E. coli and S. cerevisiae, (ii) to summarize recent literature data on E. coli and S. cerevisiae adaptive response to oxidative stress at different stages of the flow of the genetic information: from transcription and translation to functionally active proteins and (iii) to discuss possible reasons for a lack of correlation between the expression of certain antioxidant genes at different levels of cellular organization.
In vivo effects of N/OFQ(1–13)NH2 and its structural analogue [ORN9]N/OFQ(1–13)NH2 on carrageenan-induced inflammation: rat-paw oedema and antioxidant status
Authors: Zamfirova Rositsa , Tzvetanova Elina , Alexandrova Albena , Petrov Lubomir , Mateeva Polina , Pavlova Almira , Kirkova Margarita , Todorov Simeon
Published: February 2009

The effects of nociceptin(1–13)NH2 (N/OFQ(1–13)NH2) and its structural analogue [Orn9]N/OFQ(1–13)NH2 on acute carrageenan (CG)-induced peripheral inflammation and paw antioxidant status were studied. CG was injected intraplantarly in the right hind paw of rats and the volume of the inflamed paw was measured each 30 min for a period of 4h. When administered simultaneously with CG, N/OFQ(1–13)NH2 decreased the paw volume, whereas if injected 15 min before CG it had no effect. [Orn9]N/OFQ(1–13)NH2 produced the opposite effects at the same time-intervals of its administration. We also investigated whether these neuropeptides influence CG-induced changes in cell antioxidant system, especially at the 4th hour of CG administration. CG alone decreased the glutathione level and superoxide dismutase activity, as measured in post-nuclear homogenate of the inflamed paw. However, CG injection increased glutathione peroxidase and glucose-6-phospate dehydrogenase activities, while the activity of glutathione reductase was unchanged. The peptides themselves did not change all measured parameters. Moreover, neither N/OFQ(1–13)NH2 nor [Orn9]N/OFQ(1–13)NH2 modified CG-induced changes in the antioxidant status, regardless of the time of their injection (simultaneously or 15 min before CG). The present results suggest that N/OFQ(1–13)NH2 and [Orn9]N/OFQ(1–13)NH2 most likely affect the neuronal inflammation, rather than act as pro- or antioxidants.
The effects of disodium pamidronate on human polymorphonuclear leukocytes and platelets: An in vitro study
Authors: Salvolini Eleonora , Orciani Monia , Vignini Arianna , Primio Roberto , Mazzanti Laura
Published: February 2009

Recent reports have indicated that, as well as having antiresorptive effects, bisphosphonates could have an application as anti-inflammatory drugs. Our aim was to investigate whether this anti-inflammatory action could be mediated by the nitric oxide (NO) released by the leukocytes migrating to the site of inflammation. In particular, we investigated in vitro the intracellular calcium concentration ([Ca2+]i), the level of NO released by PMN and platelets, and the PMN myeloperoxidase activity after incubation with disodium pamidronate, since there was a postulated modulatory effect of this aminosubstituted bisphosphonate on leukocytes both in vitro and in vivo. Our data shows that the pamidronate treatment provoked a significant increase in the [Ca2+]i parallel to the enhancement in NO release, suggesting a possible activation of constitutive nitric oxide synthase, while the myeloperoxidase activity was significantly reduced. In conclusion, we hypothesized that treatment with pamidronate could stimulate NO-production by cells present near the bone compartment, thus constituting a protective mechanism against bone resorption occurring during inflammation. In addition, PMN- and platelet-derived NO could act as a negative feed-back signal to restrict the inflammatory processes.
The expression of protein kinase B in gastric cancer cell apoptosis induced by 12-O-tetradecanoylphorbol-1, 3-acetate
Authors: Zhang Bing , Xia Chun
Published: February 2009

Protein kinase B (PKB/Akt) is a serine-threonine kinase functioning downstream of phosphatidylinositol 3-kinase (PI-3 kinase) in response to mitogen or growth factor stimulation. In several cell types, it plays an important anti-apoptotic role. TPA is a potent regulator of the growth of many different cell types. Here, we detected that TPA could induce cell apoptosis in the gastric cancer cell line, BGC-823. We also found that TPA inhibited the expression of PKB/Akt in a TPA concentration- and time-dependent manner. Furthermore, TPA inhibited the phosphorylation of PKB at Ser473, but did not affect the phosphorylation of Thr308. It only attenuated the expression of PKB/Akt and the phosphorylation of Ser473 in the cell nucleus, whereas it did not change the PKB/Akt distribution in BGC-823 cells. These results suggest that PKB/Akt inhibition by TPA may be the important factor in the mechanism of effect of TPA on gastric cell lines.
Calcium aluminate cement hydration in a high alkalinity environment
Authors: Pastor C. , Fernández-Jiménez A. , Vázquez T. , Palomo Á.
Published: February 2009

The present paper forms part of a broader research project that aims primarily to devise new cementitious products via the alkali activation of silico-aluminous materials. This work addresses the possibility of using small percentages of calcium aluminate cement (CAC) as a source of reactive aluminium. For this reason, a preliminary review was needed of the behaviour of CACs in highly alkaline media (2, 8 and 12M NaOH solutions). Two, 28- and 180-day mechanical strength was determined and the reaction products were characterized with XRD and FTIR. The water-hydrated CAC was used as the control.The results obtained showed that CAC hardening took place much more slowly in highly alkaline media than in water. Nonetheless, the 28-day compressive strength obtained, ≥80MPa. As main reaction products, to ambient temperature and from the two days of cured, cubic aluminate C3AH6), and AH3 polymorphs are formed, instead of the usual hexagonal aluminatos (CAH10 and C2AH8) that are formed in the normal hydrate with water.
Towards optimum permeability reduction in porous media using biofilm growth simulations
Authors: Pintelon T.R.R. , Graf von der Schulenburg D.A. , Johns M.L.
Published: February 2009

While biological clogging of porous systems can be problematic in numerous processes (e.g., microbial enhanced oil recovery—MEOR), it is targeted during bio‐barrier formation to control sub‐surface pollution plumes in ground water. In this simulation study, constant pressure drop (CPD) and constant volumetric flow rate (CVF) operational modes for nutrient provision for biofilm growth in a porous system are considered with respect to optimum (minimum energy requirement for nutrient provision) permeability reduction for bio‐barrier applications. Biofilm growth is simulated using a Lattice‐Boltzmann (LB) simulation platform complemented with an individual‐based biofilm model (IbM). A biomass detachment technique has been included using a fast marching level set (FMLS) method that models the propagation of the biofilm–liquid interface with a speed proportional to the adjacent velocity shear field. The porous medium permeability reduction is simulated for both operational modes using a range of biofilm strengths. For stronger biofilms, less biomass deposition and energy input are required to reduce the system permeability during CPD operation, whereas CVF is more efficient at reducing the permeability of systems containing weaker biofilms. Biotechnol. Bioeng. 2009;103: 767–779. © 2009 Wiley Periodicals, Inc.
Localized expression profiles of rpoS in Escherichia coli biofilms
Authors: Ito Akinobu , May Thithiwat , Taniuchi Asami , Kawata Koji , Okabe Satoshi
Published: February 2009

Although importance of the rpoS gene on biofilm formation by Escherichia coli has been suggested, there has not been any report showing where the rpoS is expressed during biofilm formation process. Since physiological state of the cells in the biofilms is considerably heterogeneous, the expression of the rpoS gene must be heterogeneous. In this study, in situ spatial expression of the rpoS gene during biofilm formation was investigated with an rpoS‐gfp transcriptional fusion mutant strain. A ribosomal binding site and a gene encoding a green fluorescent protein were introduced into the downstream of the rpoS gene, which enabled us to observe the in situ spatial expression of the rpoS gene during biofilm formation processes without any disturbance of the rpoS expression. In the early stages of the biofilm formation process, the rpoS gene was expressed in the most of the cells. On the other hand, the rpoS expression was observed only at the outside of the biofilms during the late stages of the biofilm formation process. The in situ spatial expression of the rpoS gene in the biofilm was verified by quantifying the expression levels of the rpoS at the outside and the inside of the biofilms with the real time RT‐PCR. In addition, global gene expression analysis was performed with DNA microarray to investigate physiological difference between the outside and the inside of the biofilms. This heterogeneous rpoS expression profile suggested that the cells at the outside of the biofilm need to express the rpoS to shift the physiological state to the stationary growth mode such as induction of various stress responses and suppression of the motility. Biotechnol. Bioeng. 2009;103: 975–983. © 2009 Wiley Periodicals, Inc.
Evaluation of the ERETIC method as an improved quantitative reference for 1H HR‐MAS spectroscopy of prostate tissue
Authors: Albers Mark J. , Butler Thomas N. , Rahwa Iman , Bao Nguyen , Keshari Kayvan R. , Swanson Mark G. , Kurhanewicz John
Published: February 2009

The Electronic REference To access In vivo Concentrations (ERETIC) method was applied to 1H HR‐MAS spectroscopy. The accuracy, precision, and stability of ERETIC as a quantitative reference were evaluated in solution and human prostate tissue samples. For comparison, the reliability of 3‐(trimethylsilyl)propionic‐2,2,3,3‐d4 acid (TSP) as a quantitation reference was also evaluated. The ERETIC and TSP peak areas were found to be stable in solution over the short‐term and long‐term, with long‐term relative standard deviations (RSDs) of 4.10% and 2.60%, respectively. Quantification of TSP in solution using the ERETIC peak as a reference and a calibrated, rotor‐dependent conversion factor yielded results with a precision ≤2.9% and an accuracy error ≤4.2% when compared with the expected values. The ERETIC peak area reproducibility was superior to TSP's reproducibility, corrected for mass, in both prostate surgical and biopsy samples (4.53% vs. 21.2% and 3.34% vs. 31.8%, respectively). Furthermore, the tissue TSP peaks exhibited only 27.5% of the expected area, which would cause an overestimation of metabolite concentrations if used as a reference. The improved quantification accuracy and precision provided by ERETIC may enable the detection of smaller metabolic differences that may exist between individual tissue samples and disease states. Magn Reson Med 61:525–532, 2009. © 2009 Wiley‐Liss, Inc.
Is There a Survival Benefit to Neoadjuvant Versus Adjuvant Chemotherapy, Combined with Surgery for Resectable Colorectal Liver Metastases?
Authors: Lubezky Nir , Geva Ravit , Shmueli Einat , Nakache Richard , Klausner Joseph M. , Figer Arie , Ben‐Haim Menahem
Published: February 2009

Background

The benefits of adding chemotherapy to surgery in patients with hepatic colorectal metastases at moderate and high risk for recurrence and the optimal sequence of administration are undetermined.

Methods

We followed the overall‐survival and event‐free survival rates after operation in patients with resectable colorectal metastases confined to the liver. The adjuvant patients first underwent surgery and then treatment, whereas the neoadjuvant patients underwent treatment, surgery, and re‐treatment. Assignment was by oncologist and patient preferences. Chemotherapy was oxaliplatin (FOLFOX) or irinotecan (FOLFIRI) based.

Results

Fifty‐six of 105 patients who underwent liver resections for colorectal metastases (2002–2005) are included. The two groups were comparable for demographics, characteristics of disease (including recurrence risk), treatment protocols, and follow‐up. The respective 1‐, 2‐, and 3‐year overall survival rates were 91%, 91%, and 84%, and the event‐free survival rates were 63%, 49%, and 49% for the 19 adjuvant patients, and 95%, 91%, and 70%, and 94%, 50%, and 50% for the 37 neoadjuvant patients.

Conclusions

The midterm overall survival and disease‐free survival rates in this group of patients with resectable colorectal metastases to the liver, who were treated with combination of resection and chemotherapy, were similar, regardless of the sequence of treatment.
Membrane activity of a C‐reactive protein
Authors: Harrington John M. , Chou Hui-Ting , Gutsmann Thomas , Gelhaus Christoph , Stahlberg Henning , Leippe Matthias , Armstrong Peter B.
Published: February 2009

C‐reactive protein (CRP) from the American horseshoe crab, Limulus polyphemus, exhibits complex membrane activities. Here, we describe the behavior of protein and lipid as CRP interacts with model liposomes and bacterial membranes. Limulus C‐reactive protein (L‐CRP) forms extended fibrilar structures that encapsulate liposomes in the presence of Ca2+. We have observed structures consistent in size and shape with these fibers bound to the surface of Gram‐negative bacteria. The membranes of Limulus CRP‐treated bacteria exhibit significantly different mechano‐elastic properties than those of untreated bacteria. In vitro, bilayer lipids undergo a rigidification and reorganization of small domains. We suggest that these interactions reflect the protein's role as a primary defense molecule, functioning in the entrapment and killing of potential pathogens.
Structure and dynamics of the human muscle LIM protein
Authors: Schallus Thomas , Fehér Krisztina , Ulrich Anne S. , Stier Gunter , Muhle-Goll Claudia
Published: February 2009

The family of cysteine rich proteins (CRP) comprises three closely homologous members that have been reported to interact with α‐actinin. Muscular LIM protein (MLP/CRP3), the skeletal muscle variant, was originally discovered as a positive regulator of myogenesis and is suggested to be part of the stretch sensor of the myofibril through its interaction with telethonin (T‐Cap). We determined the structure of both LIM domains of human MLP by nuclear magnetic resonance spectroscopy. We confirm by 15N relaxation measurements that both LIM domains act as independent units and that the adjacent linker regions are fully flexible. With the published structures of CRP1 and CRP2, the complete family has now been structurally characterized.