bluuebunny/crossref_metadata_2025 huggingface dataset:
The Immunophenotype of Blood and Cerebrospinal Fluid Mononuclear Cells in Dogs
Authors: Duque C. , Parent J. , Bienzle D.
Published: May 2009

Inflammatory neurologic diseases are common in dogs, but establishing a definitive diagnosis often is difficult. Nucleated cell number and type in cerebrospinal fluid (CSF) rarely are suggestive of an etiologic agent. We speculated that CSF leukocyte immunophenotyping would be a useful adjunct in the investigation of canine inflammatory neurologic diseases by yielding more specific etiologic information. The goals of this study were to establish the feasibility of flow cytometric evaluation of individual canine CSF samples and to identify the cell distribution in healthy dogs. The mononuclear cell populations of paired blood and CSF samples from 23 healthy dogs were characterized by labeling of cells with antibodies against CD4, CD8α, CD21, and CD14 molecules and by flow cytometric analysis of their expression. The mean proportion of CD4+ and CD21+ cells was significantly higher in blood than in the CSF (P< .002 andP< .001, respectively). In contrast, the mean proportion of CD14+ and CD8α+ cells was not significantly different between blood and CSF (P= .5 andp= .9, respectively). These findings demonstrate differences in the distribution and function of mononuclear cells in the circulating venous and subarachnoid compartments in the dog.
Liposome‐Encapsulated Doxorubicin (Doxil) and Doxorubicin in the Treatment of Vaccine‐Associated Sarcoma in Cats
Authors: Poirier Valerie J. , Thamm Douglas H. , Kurzman Ilene D. , Jeglum K. Ann , Chun Ruthanne , Obradovich Joyce E. , O'Brien Maura , Fred Rogers M. , Phillips Brenda S. , Vail David M.
Published: May 2009

The purpose of this randomized, multicenter study was to evaluate the toxicity and efficacy of liposome‐encapsulated doxorubicin (LED) and doxorubicin (DOX) in the treatment of feline vaccine‐associated sarcoma (VAS). Cats were divided according to their disease status into a microscopic arm (no evidence of gross disease) and a macroscopic arm (evidence of gross disease). Each arm was randomized to receive either LED (1–1.5 mg/kg IV q3weeks) or DOX (1 mg/kg IV q3weeks). Thirty‐three cats were entered in the macroscopic arm of the study with an overall response rate of 39% (5 complete response and 8 partial response) and a median time to progression of 84 days. Response rates were not different between LED and DOX. Seventy‐five cats were entered into the microscopic arm. When compared to a similar historical control population treated with surgery alone, the cats receiving chemotherapy had a prolonged median disease‐free interval (388 days versus 93 days). No difference in efficacy was detected between LED and DOX. LED at 1.5 mg/kg induced delayed nephrotoxicosis in 23%, necessitating a decrease in the recommended dosage to 1 mg/kg, and cutaneous toxicosis in 21.7% of treated cats. This study showed that both DOX and LED are efficacious in the treatment of VAS and should be considered in the treatment of this tumor.
Intravenous Lidocaine and Small‐Intestinal Size, Abdominal Fluid, and Outcome after Colic Surgery in Horses
Authors: Brianceau P. , Chevalier H. , Karas A. , Court M.H. , Bassage L. , Kirker‐Head C. , Provost P. , Paradis MR.
Published: May 2009

Twenty‐eight horses with the diagnosis of an intestinal disorder requiring surgical intervention were randomly assigned to lidocaine (n = 13) or saline (control, n = 15) treatment groups. After induction of anesthesia, treated horses received a loading dose of 2% lidocaine (0.65 mg/kg) intravenously, followed by a continuous rate of infusion of 1% lidocaine (0.025 mg/kg/min) until the discontinuation of anesthesia. Upon recovery from anesthesia, a 2nd loading dose of 2% lidocaine (1.3 mg/kg) was administered, followed by an infusion of 1% lidocaine (0.05 mg/kg/min) for 24 hours postoperatively. The control group received equivalent volumes of saline. Lidocaine‐treated horses had significantly better minimum jejunal cross‐sectional area scores (P= .011), minimum jejunal diameter scores (P= .002), and intestinal ultrasound index (IUI) (P= .007). Peritoneal fluid was detected by percutaneous ultrasound examination in 8 of the 15 control animals but in none of the treated animals (P= .003). Failure to obtain fluid via abdominocentesis was significantly more frequent for lidocaine‐treated horses (P= .025). No significant differences between the groups were found in the presence of gastrointestinal sounds, time to passage of 1st feces, number of defecations in the 1st 24 hours, presence of gastric reflux, duodenal or jejunal wall thickness, maximum duodenal or jejunal diameter or cross‐sectional area, minimum duodenal diameter or cross‐sectional area, duodenal and jejunal intraluminal echogenicity, small‐intestinal contractions per minute, rate of complications, or outcome. On the basis of this study, lidocaine infusion may have some desirable effects on jejunal distension and peritoneal fluid accumulation and was well tolerated perioperatively in horses with colic. The low incidence of small‐intestinal lesions and gastric reflux in the study makes it difficult to assess the use of lidocaine in the prevention of postoperative ileus (POI).
Treatment with Pergolide or Cyproheptadine of Pituitary Pars Intermedia Dysfunction (Equine Cushing's Disease)
Authors: Donaldson Mark T. , LaMonte Bemadette H. , Morresey Peter , Smith Gary , Beech Jill
Published: May 2009

Medical records of 27 horses (including 13 ponies) treated with pergolide or cyproheptadine for pituitary pars intermedia dysfunction were reviewed to determine the effect of treatment on plasma ACTH, insulin, and glucose concentrations and clinical signs. Prior to treatment, the most common clinical signs were laminitis, hirsutism, and abnormal body fat distribution. The median pergolide dose was 3.0 μLg/kg PO q24h (range, 1.7–5.5 ±g/kg). All horses treated with cyproheptadine were given 0.25 mg/kg PO q24h. After pergolide treatment, ACTH concentrations (n = 20; median = 30.4 pg/ml; range, 4.2–173) were significantly lower (P< .01) than those in horses treated with cyproheptadine (n = 7; median = 141.0 pg/ml; range, 10–1,230). Among horses treated with pergolide, there was a correlation between ACTH concentration after treatment and the duration of treatment (P< .001) and pergolide dose (P= .04). Significantly (P= .02) more owners of horses treated with pergolide (85%, 17/20) reported an improvement in clinical signs compared to owners of horses treated with cyproheptadine (28%, 2/7).
Adrenaline but not noradrenaline is a determinant of exercise‐induced lipid mobilization in human subcutaneous adipose tissue
Authors: De Glisezinski I. , Larrouy D. , Bajzova M. , Koppo K. , Polak J. , Berlan M. , Bulow J. , Langin D. , Marques M. A. , Crampes F. , Lafontan M. , Stich V.
Published: May 2009

The relative contribution of noradrenaline (norepinephrine) and adrenaline (epinephrine) in the control of lipid mobilization in subcutaneous adipose tissue (SCAT) during exercise was evaluated in men treated with a somatostatin analogue, octreotide. Eight lean and eight obese young men matched for age and physical fitness performed 60 min exercise bouts at 50% of their maximal oxygen consumption on two occasions: (1) duringi.v.infusion of octreotide, and (2) during placebo infusion. Lipolysis and local blood flow changes in SCAT were evaluated usingin situmicrodialysis. Infusion of octreotide suppressed plasma insulin and growth hormone levels at rest and during exercise. It blocked the exercise‐induced increase in plasma adrenaline while that of noradrenaline was unchanged. Plasma natriuretic peptides (NPs) level was higher at rest and during exercise under octreotide infusion in lean men. Under placebo, no difference was found in the exercise‐induced increase in glycerol between the probe perfused with Ringer solution alone and that with phentolamine (an α‐adrenergic receptor antagonist) in lean subjects while a greater increase in glycerol was observed in the obese subjects. Under placebo, propranolol infusion in the probe containing phentolamine reduced by about 45% exercise‐induced glycerol release; this effect was fully suppressed under octreotide infusion while noradrenaline was still elevated and exercise‐induced lipid mobilization maintained in both lean and obese individuals. In conclusion, blockade of β‐adrenergic receptors during exercise performed during infusion of octreotide (blocking the exercise‐induced rise in adrenaline but not that of noradrenaline) does not alter the exercise‐induced lipolysis. This suggests that adrenaline is the main adrenergic agent contributing to exercise‐induced lipolysis in SCAT. Moreover, it is the combined action of insulin suppression and NPs release which explains the lipolytic response which remains under octreotide after full local blockade of fat cell adrenergic receptors. For the moment, it is unknown if results apply specifically to SCAT and exercise only or if conclusions could be extended to all forms of lipolysis in humans.
Location and properties of respiratory neurones with putative intrinsic bursting properties in the rat in situ
Authors: St.‐John Walter M. , Stornetta Ruth L. , Guyenet Patrice G. , Paton Julian F.R.
Published: May 2009

Using the in situ arterially perfused preparations of both neonatal and juvenile rats, we provide the first description of the location, morphology and transmitter content of a population of respiratory neurones that retains a bursting behaviour after ionotropic receptor blockade. All burster neurones exhibited an inspiratory discharge during eupnoeic respiration. These neurones were predominantly glutamatergic, and were located within a region of the ventral respiratory column that encompasses the pre‐Bötzinger complex and the more caudally located ventral respiratory group. Bursting behaviour was both voltage and persistent sodium current dependent and could be stimulated by sodium cyanide to activate this persistent sodium current. The population of burster neurones may overlap with that previously described in the neonatal slice in vitro. Based upon the present and previous findings, we hypothesize that this burster discharge may be released when the brain is subject to severe hypoxia or ischaemia, and that this burster discharge could underlie gasping.
Precise and high-speed control of partial pressures of multiple gas species in plasma process chamber using pulse-controlled gas injection
Authors: Morishita Sadaharu , Goto Tetsuya , Nagase Masaaki , Ohmi Tadahiro
Published: May 2009

Multiprocesses in a single plasma process chamber with high throughput require precise, sequential, high-speed alteration of partial pressures of multiple gas species. A conventional gas-distribution system cannot realize this because the system seriously overshoots gas pressure immediately following valve operation. Furthermore, chamber volume and conductance of gas piping between the system and chamber should both be considered because they delay the stabilizing time of gas pressure. Therefore, the authors proposed a new gas-distribution system without overshoot by controlling gas flow rate based on pressure measurement, as well as a method of pulse-controlled gas injection immediately following valve operation. Time variation of measured partial pressure agrees well with a calculation based on an equivalent-circuit model that represents the chamber and gas piping between the system and chamber. Using pulse-controlled gas injection, the stabilizing time can be reduced drastically to 0.6s for HBr added to pure Ar plasma, and 0.7s for O2 added to Ar∕HBr plasma; without the pulse control, the stabilizing times are 3 and 7s, respectively. In the O2 addition case, rapid stabilization can be achieved during the period of line/space pattern etching of poly-Si on a thin SiO2 film. This occurs without anomalous etching of the underlying SiO2 film or the Si substrate near the sidewall, thus obtaining a wide process margin with high throughput.
Deep Modification of materials by thermal stress wave generated by irradiation of high-current pulsed electron beams
Authors: Qin Ying , Dong Chuang , Song Zhenfei , Hao Shengzhi , Me Xianxiu , Li Jingan , Wang Xiaogang , Zou Jianxin , Grosdidier Thierry
Published: May 2009

High-current pulsed electron beams generate modifications in materials over a depth range of a few hundred micrometers, far beyond the heat-affected zone. In this article, the authors presented relevant experimental results in a stainless steel substrate and described the associated transient thermal and stress processes. They attributed the deep modification to an intense stress wave arising from drastic heating of the materials about 2∼3μm below the surface as a result of the deep penetration of electrons. Thanks to the large amplitude at several gigapscals the stress wave exerted intense impacts over a long distance. They also revealed that the interactions were dependent on the grain orientation.
Transport and structural properties of silicon films in the amorphous-to-microcrystalline transition region
Authors: Mukhopadhyay Sumita , Goswami Romyani , Ray Swati
Published: May 2009

Undoped hydrogenated microcrystalline silicon (μc-Si:H) thin films have been deposited by plasma enhanced chemical vapor deposition (PECVD) at low temperature with different hydrogen dilutions and rf powers. Large complexity of microstructure in hydrogenated microcrystalline silicon and the existence of different sizes of crystallites are demonstrated by different characterizations. The authors correlate the transport properties with the structural properties of the rf PECVD grown μc-Si:H in the amorphous-to-crystalline transition region. For chamber pressure of 2.0Torr and rf power density of 310mW∕cm2, the onset of crystallinity is observed for the film deposited at a hydrogen dilution of 94%. At a hydrogen dilution of 95%, amorphous-to-microcrystalline transition have been observed. This film exhibits a dark conductivity of 2.7×10−7Scm−1 and a crystalline volume fraction of 21%. The mobility-lifetime product for these films are 3.8×10−6cm2∕V and hole diffusion length is 70nm. Fourier transform infrared study shows mainly monohydride bonding in this film. This film becomes stable after 30h of light soaking.
Investigation of interfacial layer development between thin Al2O3 films grown using atomic layer deposition and Si(100), Ge(100), or GaAs(100)
Authors: Lamagna L. , Scarel G. , Fanciulli M. , Pavia G.
Published: May 2009

The uncontrolled formation of an interfacial layer between high-κ oxides and semiconductors is a major concern in advanced microelectronics not only for Si-based devices but also for those exploiting the higher mobility of Ge and GaAs. Using transmission electron microscopy, the authors investigate the interfacial layer formed between as-grown thin Al2O3 films, deposited using atomic layer deposition, and oxide free Si(100), Ge(100), and GaAs(100). In particular, they compare the effects of two different oxygen sources (H2O and O3) on interfacial layer formation during the growth process. They show that no interfacial layer can be distinguished unambiguously between the Al2O3 films, grown using TMA and H2O or O3, and all the semiconductor substrates.
Differential etching behavior between semi-insulating and n-doped 4H-SiC in high-density SF6/O2 inductively coupled plasma
Authors: Okamoto Naoya
Published: May 2009

The author investigated the etching characteristics of semi-insulating (SI) and n-doped (n-) 4H-SiC substrates at a high etch rate of about 2 μm/min using high-density SF6/O2 inductively coupled plasma. The etch rate of SI-SiC was found to be lower than that of n-SiC, and the etching profile of SI-SiC showed retrograde features with a larger sidewall angle and a rounder etched bottom compared to n-SiC. These characteristics are attributed to the difference in wafer heating and negative charging of the sidewall during plasma etching between both substrates. The temperature of n-SiC increases by radiative heating from the high-density plasma during etching because of the higher free-carrier absorption compared to SI-SiC. Furthermore, the negative charge buildup at the sidewall of SI-SiC becomes stronger because of the lower electrical conductivity compared to n-SiC.
Auger electron spectroscopy study of reactor walls in transition from an O2 to a Cl2 plasma
Authors: Guha Joydeep , Donnelly Vincent M.
Published: May 2009

In plasma etching processes, the reactor wall conditions can change over time due to a number of intentional and unintentional reasons, leading to a variability in the radical number densities in the plasma, caused by changes in the probabilities for reactions such as recombination at the walls. This leads to loss of reproducibility in the etching process. Here the authors isolated one such effect in which the feed gas was changed in the absence of a substrate. The transient surface composition of an anodized aluminum surface was determined for inductively coupled plasmas as the gas was switched from Cl2 to O2 and vice versa. The study was carried out with the spinning wall method and Auger electron spectroscopy. When the surface was first conditioned in an O2 plasma and then exposed to Cl2 plasmas, a rapid uptake of Cl was found in the first tens of seconds, followed by a slow approach to a steady-state value within ∼5min of plasma exposure. Conversely, when the surface was exposed to a Cl2 plasma for a long time and then switched to an O2 plasma, the anodized aluminum surface underwent a rapid dechlorination in the first few seconds and then a slow approach to steady state over ∼3min. Throughout these treatments, the coverages of Si (from erosion of the quartz discharge tube) and O were nearly constant.
Rarefied gas flow through a thin slit into vacuum simulated by the Monte Carlo method over the whole range of the Knudsen number
Authors: Sharipov Felix , Kozak Dalton V.
Published: May 2009

A rarefied gas flow through a thin slit into vacuum is studied on the basis of the direct simulation Monte Carlo method. The mass flow rate and flow field are calculated over the whole range of the gas rarefaction from the free-molecular regime to the viscous one. A comparison to other results on the same problem available in literature is performed. An interpolating formula for the reduced flow rate is obtained.
Addition of yttrium into HfO2 films: Microstructure and electrical properties
Authors: Dubourdieu C. , Rauwel E. , Roussel H. , Ducroquet F. , Holländer B. , Rossell M. , Van Tendeloo G. , Lhostis S. , Rushworth S.
Published: May 2009

The cubic phase of HfO2 was stabilized by addition of yttrium in thin films grown on Si∕SiO2 by metal-organic chemical vapor deposition. The cubic phase was obtained for contents of 6.5at.% Y or higher at a temperature as low as 470°C. The complete compositional range (from 1.5to99.5at.% Y) was investigated. The crystalline structure of HfO2 was determined from x-ray diffraction, electron diffraction, and attenuated total-reflection infrared spectroscopy. For cubic films, the continuous increase in the lattice parameter indicates the formation of a solid-solution HfO2–Y2O3. As shown by x-ray photoelectron spectroscopy, yttrium silicate is formed at the interface with silicon; the interfacial layer thickness increases with increasing yttrium content and increasing film thickness. The dependence of the intrinsic relative permittivity εr as a function of Y content was determined. It exhibits a maximum of ∼30 for ∼8.8at.% Y. The cubic phase is stable upon postdeposition high-temperature annealing at 900°C under NH3.
Optimization of cell geometry for a conventional sputter ion pump by a particle-in-cell simulation
Authors: Ha Taekyun , Chung Sukmin , Park C. D.
Published: May 2009

The authors performed simulations of Penning discharge at the low magnetic field using a particle-in-cell computer code to derive the optimum cell geometry of a sputter ion pump (SIP). The energy and angle distributions of incident ions on the cathode of a Penning cell were directly obtained from the simulation. Based on these data, the authors calculated the amount of deposited Ti on the inner surface of the cell, which was found to be proportional to intrinsic pumping speed of a SIP, and then estimated the effective pumping speed for various cell geometries. In this calculation, the incident ions on the outer region of the cathode as well as those at the center were analyzed, and the effect of the ionizationless region on Penning discharge was also taken into account. The calculated values agreed well with the existing experimental data, especially in the region of a small cell radius. The results also show that the cell radius should be at least 5 mm for effective pumping, and the optimum geometrical parameters for a conventional sputter ion pump have the radius of 8.5 mm and the gap of 7 mm at the applied voltage of 5600 V.
Influence of deposition pressure and pulsed dc sputtering on pumping properties of Ti–Zr–V nonevaporable getter films
Authors: Malyshev O. B. , Valizadeh R. , Colligon J. S. , Hannah A. , Middleman K. J. , Patel S. , Vishnyakov V. M.
Published: May 2009

The performance of a UHV vessel can be improved with a new CERN technology nonevaporable getter (NEG) coating, which is already widely used for accelerator vacuum chambers. Better understanding of the processes involved in NEG film deposition, activation, and poisoning should allow optimization and engineering of the film properties, which are necessary for a particular application. Ti–Zr–V NEG films were created by magnetron sputtering from a single Ti–Zr–V target, and the NEG performance and morphology dependence on deposition pressure, sputtering conditions, and substrate surface roughness have been investigated. It was found that the average grain size of the Ti–Zr–V film was 5–6 nm and was broadly independent of the substrate material and deposition conditions. However, film topography and density were shown to depend very much on the substrate surface roughness and deposition conditions. Rough substrates, high working pressures, and the absence of ion bombardment produced open columnar structures, whereas smooth substrates, ion assistance, and low pressures produced much denser layers. X-ray photoelectron spectroscopy studies have shown that full regeneration occurred at 300 °C but film activation started at temperatures of as low as 160 °C. The CO sticking probability reaches its maximum after activation at 250 °C and is found to be up to 0.3 with a pumping capacity in the range of 0.8–1.2 ML. The samples activated at 160 °C have a reduced pumping speed and capacity by an order of magnitude.
Efficiency derivation for the Knudsen pump with and without thermal losses
Authors: Copic Davor , McNamara Shamus
Published: May 2009

This article describes the derivation of the efficiency for the Knudsen pump for two cases. First, by neglecting the thermal losses to calculate the maximum efficiency, and second, by including the thermal losses along the length of the channel. The Knudsen pump is a thermally driven pump with no moving parts and which functions on the principle of thermal transpiration. Diffusion is the main mode of mass transport, as opposed to bulk fluid motion. The pump functions when the gases are in a rarefied state. The efficiency without thermal losses is shown to asymptotically approach the value of the ideal gas constant divided by the specific heat capacity, while the efficiency with thermal losses is given for rectangular and circular cross sections and is shown to be independent of length.
Sputter-deposited (Pb,La)(Zr,Ti)O3 thin films: Effect of substrate and optical properties
Authors: Nordseth Ørnulf , Tybell Thomas , Grepstad Jostein K. , Røyset Arne
Published: May 2009

Optically transparent (Pb,La)(Zr,Ti)O3 (PLZT) thin films were sputter-deposited on SrTiO3(001) and MgO(001) substrates with a SrRuO3(110) bottom electrode. X-ray diffraction analysis showed epitaxial growth of monocrystalline PLZT, with (001) rocking curve full width at half maxima of ∼0.03° and ∼0.3° for films deposited on SrTiO3 and MgO, respectively. In-plane epitaxial alignment of the SrRuO3 and PLZT epilayers was verified from φ-scans. It was established from atomic force microscopy measurements that the PLZT surface roughness meets the requirement for optical waveguide applications. Recorded P-E loops for films grown on both substrates showed a remanent polarization of ∼36 μC/cm2. The refractive index of the PLZT layer was estimated from rutile prism coupling measurements at ∼2.56 for λ=633 nm, consistent with data obtained by spectroscopic ellipsometry. The ferroelectric and optical characteristics of the films, as well as their surface roughness, were not appreciably different for the two substrates. This makes MgO the preferred choice of substrate for optical waveguide devices due to its low refractive index compared to that of SrTiO3.
Evolution of metal-compound residues on the walls of plasma etching reactor and their effect on critical dimensions of high-k/metal gate
Authors: Iwakoshi Takehisa , Ono Tetsuo , Aoyama Takayuki , Nara Yasuo , Ohji Yuzuru
Published: May 2009

It was found that critical dimensions of high-k/metal gates obey the multivariate linear approximation with the precision of 3σ=±0.86nm, whose explanatory variables are amounts of metal compounds remaining on the plasma reactor walls. To measure their amounts, the authors assumed they are proportional to amounts of atoms sputtered out by Ar plasma and falling onto a Si wafers placed on a wafer stage. In this study, effects of metal compounds of W, Ti, Ta, and Hf, which are used to construct full-metal/high-k gates, were measured. It was found that Ti and Ta compounds dominate the fluctuation of critical dimensions and the dependency of their amount on wafer numbers being etched obeys a simple difference equation. From these results, they can estimate and minimize the fluctuations of critical dimensions in mass fabrications.
Influence of reactive sputter deposition conditions on crystallization of zirconium oxide thin films
Authors: Sethi Guneet , Sunal Paul , Horn Mark W. , Lanagan Michael T.
Published: May 2009

Zirconium oxide thin films were prepared through reactive magnetron sputtering with a zirconium target using pulsed-dc and radio frequency (rf) sources. The film crystallization was studied with respect to sputtering growth variables such as sputtering power, sputtering pressure, source frequency, oxygen pressure, substrate temperature, and substrate material. The crystallization was studied through x-ray diffraction (XRD) 2θ scans and was quantified with peak full width at half maximum and crystallite size. Crystallization of the films was found to occur over a broad range of sputter deposition parameters, while the amorphous phase was produced only at high sputtering pressure and low sputtering power. With a decrease in sputtering pressure or power, the crystallite size decreased. Energy dispersive x-ray spectroscopy, electron microscopy, and XRD analysis revealed that at very low pressures, these films are polyphase assemblages of cubic phases of oxygen deficient zirconium oxides such as ZrO and Zr2O. When the sputtering oxygen content of these films is increased above 25%, monoclinic-ZrO2 phase is stabilized in the films and the deposition rate decreases. However, in the case of rf sputtering, an additional peak corresponding to tetragonal phase of ZrO2 is observed. The sputtering parameters were related to physical parameters such as sputtering mode, ion energy, and substrate temperature, which influence crystallinity.
On the effect of Ta on improved oxidation resistance of Ti–Al–Ta–N coatings
Authors: Pfeiler M. , Scheu C. , Hutter H. , Schnöller J. , Michotte C. , Mitterer C. , Kathrein M.
Published: May 2009

Formation of protective oxide scales is the main reason for the high oxidation resistance of TiAlN based coatings. Here the authors report on further improvement in the oxidation resistance of TiAlN by Ta alloying. An industrial-scale cathodic arc evaporation facility was used to deposit Ti–Al–Ta–N coatings from powder metallurgically produced Ti38Al57Ta5 targets. After oxidation in ambient air, a significantly reduced oxide layer thickness in comparison to unalloyed TiAlN reference material was observed. Energy-dispersive x-ray spectroscopy line scans and secondary ion mass spectroscopy depth profiling showed that the oxide scale consists of an Al-rich top layer without detectable amount of Ta and a Ti–Ta-rich sublayer. Transmission electron microscopy investigations revealed α-Al2O3, rutile-type TiO2, and anatase-type TiO2 as the scale forming oxides. Furthermore, the Ti–Ta-rich sublayer consists of a porous layer at the oxide-nitride interface but appears dense toward the Al-rich top layer. The improved oxidation resistance is explained by doping the TiO2 lattice by replacing Ti4+ with Ta5+ in the rutile lattice, which decreases the oxygen mass transport. This leads to reduced oxidation of Ti under formation of TiO2 at the oxide-nitride interface and is the reason for the excellent oxidation behavior of Ti–Al–Ta–N coatings.
Interactions between organic photoconductor and plasma discharge within an electrophotographic environment
Authors: Nauka K. , Chang Seongsik , Ng Hou T.
Published: May 2009

Structural and chemical compositional changes occurring within the surface region of an organic photoconductor electrically charged with Paschen discharge over an extended period of time have been investigated with the help of attenuated total reflectance Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy. Experimental conditions were selected to simulate interactions between the photoconductor and the plasma discharge occurring in a typical electrophotographic printing environment. A long time exposure of the photoconductor to energetic charged and neutral species, and UV photons impinging upon the photoconductor caused oxidation of the surface, substantial chemical bond breakage, and the reformation of bonding configurations within the region below the surface. These resulted in the formation of a thin surface region with properties different from those of the original photoconductor. Since this study closely follows a modern electrophotographic process, the obtained conclusions are applicable to any electrophotographic printing engine.
Atomic layer deposition growth of a novel mixed-phase barrier for seedless copper electroplating applications
Authors: Kumar Sumit , Greenslit Daniel , Chakraborty Tonmoy , Eisenbraun Eric T.
Published: May 2009

A novel plasma-enhanced atomic layer deposition-grown mixed-phase/nanolaminate Ru–TaN barrier has been investigated, and it was confirmed that the copper diffusion barrier and direct-plate characteristics of the mixed-phase barrier can be modulated by varying the metal ratio in the film. This liner was subsequently optimized to yield a composition that combines the robust barrier properties of TaN with direct-plate characteristics of Ru. It was found that the deposited multicomponent system consists of individual crystalline and amorphous phase regions distributed across the barrier. The resulting optimized mixed-phase barrier was found to exhibit excellent copper diffusion barrier characteristics in layers as thin as 2 nm. A high degree of (111) texture (>84%) was observed for the direct-plated copper on this Ru–TaN barrier, which was very similar to the electroplated Cu deposited on a physical vapor deposition copper-seed control sample. Additionally, the filling characteristics in sub-50-nm features were found to be equivalent to those of conventionally copper-seeded interconnect structures.
Sound fields in generally shaped curved ear canals
Authors: Hudde H. , Schmidt S.
Published: May 2009

The sound field in the external ear can be subdivided into a distinctly three-dimensional part in front of pinna and concha, a fairly regular part in the core region of ear canals, and a less regular part in the drum coupling region near the tympanic membrane. The different parts of the sound field and their interaction have been studied using finite elements. A “pinna box” enclosing the pinna provides both a realistic coupling of the external space to the ear canal and the generation of sound. The sound field in the core region turns out to be not that regular as mostly assumed: near pressure minima and maxima “one-sided” isosurfaces (surfaces of equal pressure magnitude) occur, which are inconsistent with the notion of a middle axis, in principle. Nevertheless such isosurfaces can be seen as part of a “fundamental sound field,” which is governed by the principle of minimum energy. Actually, the sound transformation through narrow ducts is little affected by one-sided isosurfaces in between. As expected, the beginning of the core region depends on frequency. If the full audio range up to 20 kHz is to be covered, a location in the first bend of the ear canal is found.
Three-dimensional source tracking in an uncertain environment
Authors: Tollefsen Dag , Dosso Stan E.
Published: May 2009

This paper develops an approach to three-dimensional source tracking in an uncertain ocean environment using a horizontal line array (HLA). The tracking algorithm combines matched-field focalization for environmental (seabed and water column) and source-bearing model parameters with the Viterbi algorithm for range-depth estimation and includes physical constraints on source velocity. The ability to track a source despite environmental uncertainty is examined using synthetic test cases for various track geometries and with varying degrees of prior information for environmental parameters. Performance is evaluated for a range of signal-to-noise ratios in terms of the probability of estimating a track within acceptable position/depth errors. The algorithm substantially outperforms tracking with poor environmental estimates and generally obtains results close to those obtained with exact environmental knowledge. The approach is also applied to measured narrowband data recorded on a bottom-moored HLA in shallow water (the Barents Sea) and shown to successfully track both a towed submerged source and a surface ship in cases where simpler tracking algorithms failed.
Microbubble tunneling in gel phantoms
Authors: Caskey Charles F. , Qin Shengping , Dayton Paul A. , Ferrara Katherine W.
Published: May 2009

Insonified microbubbles were observed in vessels within a gel with a Young’s modulus similar to that of tissue, demonstrating shape instabilities, liquid jets, and the formation of small tunnels. In this study, tunnel formulation occurred in the direction of the propagating ultrasound wave, where radiation pressure directed the contact of the bubble and gel, facilitating the activity of the liquid jets. Combinations of ultrasonic parameters and microbubble concentrations that are relevant for diagnostic imaging and drug delivery and that lead to tunnel formation were applied and the resulting tunnel formation was quantified.
Thermoacoustic mixture separation with an axial temperature gradient
Authors: Geller D. A. , Swift G. W.
Published: May 2009

The theory of thermoacoustic mixture separation is extended to include the effect of a nonzero axial temperature gradient. The analysis yields a new term in the second-order mole flux that is proportional to the temperature gradient and to the square of the volumetric velocity and is independent of the phasing of the wave. Because of this new term, thermoacoustic separation stops at a critical temperature gradient and changes direction above that gradient. For a traveling wave, this gradient is somewhat higher than that predicted by a simple four-step model. An experiment tests the theory for temperature gradients from 0 to 416 K/m in 50–50 He–Ar mixtures.
Fluid loading effects for acoustical sensors in the atmospheres of Mars, Venus, Titan, and Jupiter
Authors: Leighton T. G.
Published: May 2009

This paper shows that corrections for fluid loading must be undertaken to Earth-based calibrations for planetary probe sensors, which rely on accurate and precise predictions of mechanical vibrations. These sensors include acoustical instrumentation, and sensors for the mass change resulting from species accumulation upon oscillating plates. Some published designs are particularly susceptible (an example leading to around an octave error in the frequency calibration for Venus is shown). Because such corrections have not previously been raised, and would be almost impossible to incorporate into drop tests of probes, this paper demonstrates the surprising results of applying well-established formulations.
Spherical loudspeaker array for local active control of sound
Authors: Rafaely Boaz
Published: May 2009

Active control of sound has been employed to reduce noise levels around listeners’ head using destructive interference from noise-canceling sound sources. Recently, spherical loudspeaker arrays have been studied as multiple-channel sound sources, capable of generating sound fields with high complexity. In this paper, the potential use of a spherical loudspeaker array for local active control of sound is investigated. A theoretical analysis of the primary and secondary sound fields around a spherical sound source reveals that the natural quiet zones for the spherical source have a shell-shape. Using numerical optimization, quiet zones with other shapes are designed, showing potential for quiet zones with extents that are significantly larger than the well-known limit of a tenth of a wavelength for monopole sources. The paper presents several simulation examples showing quiet zones in various configurations.
A simple method avoiding non-uniqueness in the boundary element method for acoustic scattering problem
Authors: Hirosawa Kunikazu , Ishizuka Takashi , Fujiwara Kyoji
Published: May 2009

The boundary element method (BEM) is widely used for sound field analysis problems; however, it has a non-uniqueness problem in the exterior domain. Various methods to avoid this problem have been developed; however, these are not easily applied to the BEM. In this paper, a simple method called the “ICA-Ring (inner cavity ringing) method” is proposed for avoiding the non-uniqueness problem, and this method is applied to the BEM in both single and plural domains. The concept of the ICA-Ring method is that a scatterer in free space is hollowed as a shell and the volume is smaller; the eigenfrequencies are shifted to a higher range. Next, the mechanism of the non-uniqueness problem in plural domains and a reason of the application of the ICA-Ring method to the case of plural domains are explained. Finally, some results calculated by the BEM using the ICA-Ring method are shown. The calculational condition is that a cylinder with radius 0.125m floats in two-dimensional free space. In this case, no calculational errors exist in 1–6000Hz in both single and plural domains, when the thickness of the shell is 20mm. The ICA-Ring method does not need to modify an existing computer program of conventional BEM.
Escherichia coli
O157:H7 and Other
E. coli
Strains Share Physiological Properties Associated with Intestinal Colonization
Authors: Jacobsen Lisa , Durso Lisa , Conway Tyrell , Nickerson Kenneth W.
Published: May 2009

Escherichia coli
isolates (72 commensal and 10 O157:H7 isolates) were compared with regard to physiological and growth parameters related to their ability to survive and persist in the gastrointestinal tract and found to be similar. We propose that nonhuman hosts in
E. coli
O157:H7 strains function similarly to other
E. coli
strains in regard to attributes relevant to gastrointestinal colonization.
New Insights into γ-Aminobutyric Acid Catabolism: Evidence for γ-Hydroxybutyric Acid and Polyhydroxybutyrate Synthesis inSaccharomyces cerevisiae
Authors: Bach Benoît , Meudec Emmanuelle , Lepoutre Jean-Paul , Rossignol Tristan , Blondin Bruno , Dequin Sylvie , Camarasa Carole
Published: May 2009

The γ-aminobutyrate (GABA) shunt, an alternative route for the conversion of α-ketoglutarate to succinate, involves the glutamate decarboxylase Gad1p, the GABA transaminase Uga1p and the succinate semialdehyde dehydrogenase Uga2p. This pathway has been extensively described in plants and animals, but its function in yeast remains unclear. We show that the flux through Gad1p is insignificant during fermentation in rich sugar-containing medium, excluding a role for this pathway in redox homeostasis under anaerobic conditions or sugar stress. However, we found that up to 4 g of exogenous GABA/liter was efficiently consumed by yeast. We studied the fate of this consumed GABA. Most was converted into succinate, with a reaction yield of 0.7 mol/mol. We also showed that a large proportion of GABA was stored within cells, indicating a possible role for this molecule in stress tolerance mechanisms or nitrogen storage. Furthermore, based on enzymatic and metabolic evidence, we identified an alternative route for GABA catabolism, involving the reduction of succinate-semialdehyde into γ-hydroxybutyric acid and the polymerization of γ-hydroxybutyric acid to form poly-(3-hydroxybutyric acid-co-4-hydroxybutyric acid). This study provides the first demonstration of a native route for the formation of this polymer in yeast. Our findings shed new light on the GABA pathway and open up new opportunities for industrial applications.
Clonal Population Structure and Antimicrobial Resistance ofCampylobacter jejuniin Chicken Meat from Belgium
Authors: Habib Ihab , Miller William G. , Uyttendaele Mieke , Houf Kurt , De Zutter Lieven
Published: May 2009

Campylobacter jejuniis one of the most important causes of human diarrhea worldwide. In the present work, multilocus sequence typing was used to study the genotypic diversity of 145C. jejuniisolates from 135 chicken meat preparations sampled across Belgium. Isolates were further typed by pulsed-field gel electrophoresis, and their susceptibilities to six antimicrobials were determined. Fifty-seven sequence types (STs) were identified; 26.8% of the total typed isolates were ST-50, ST-45, or ST-257, belonging to clonal complex CC-21, CC-45, or CC-257, respectively. One clonal group comprised 22% (32/145) of all isolates, originating from five different companies and isolated over seven sampling months. Additionally, 53.1% ofC. jejuniisolates were resistant to ciprofloxacin, and 48.2% were resistant to tetracycline; 28.9% (42/145) of all isolates were resistant to both ciprofloxacin and tetracycline. The correlation between certainC. jejuniclonal groups and resistance to ciprofloxacin and tetracycline was notable.C. jejuniisolates assigned to CC-21 (n= 35) were frequently resistant to ciprofloxacin (65.7%) and tetracycline (40%); however, 90% (18/20) of the isolates assigned to CC-45 were pansusceptible. The present study demonstrates that certainC. jejunigenotypes recur frequently in the chicken meat supply. The results of molecular typing, combined with data on sample sources, indicate a possible dissemination ofC. jejuniclones with high resistance to ciprofloxacin and/or tetracycline. Whether certain clonal groups are common in the environment and repeatedly infect Belgian broiler flocks or whether they have the potential to persist on farms or in slaughterhouses needs further investigation.
bdhA-patD
Operon as a Virulence Determinant, Revealed by a Novel Large-Scale Approach for Identification of
Legionella pneumophila
Mutants Defective for Amoeba Infection
Authors: Aurass P. , Pless B. , Rydzewski K. , Holland G. , Bannert N. , Flieger A.
Published: May 2009

Legionella pneumophila
, the causative agent of Legionnaires' disease, is an intracellular parasite of eukaryotic cells. In the environment, it colonizes amoebae. After being inhaled into the human lung, the bacteria infect and damage alveolar cells in a way that is mechanistically similar to the amoeba infection. Several
L. pneumophila
traits, among those the Dot/Icm type IVB protein secretion machinery, are essential for exploiting host cells. In our search for novel
Legionella
virulence factors, we developed an agar plate assay, designated the scatter screen, which allowed screening for mutants deficient in infecting
Acanthamoeba castellanii
amoebae. Likewise, an
L. pneumophila
clone bank consisting of 23,000 transposon mutants was investigated here, and 19 different established
Legionella
virulence genes, for example,
dot
/
icm
genes, were identified. Importantly, 70 novel virulence-associated genes were found. One of those is
L. pneumophila bdhA
, coding for a protein with homology to established 3-hydroxybutyrate dehydrogenases involved in poly-3-hydroxybutyrate metabolism. Our study revealed that
bdhA
is cotranscribed with
patD
, encoding a patatin-like protein of
L. pneumophila
showing phospholipase A and lysophospholipase A activities. In addition to strongly reduced lipolytic activities and increased poly-3-hydroxybutyrate levels, the
L. pneumophila bdhA-patD
mutant showed a severe replication defect in amoebae and U937 macrophages. Our data suggest that the operon is involved in poly-3-hydroxybutyrate utilization and phospholipolysis and show that the
bdhA-patD
operon is a virulence determinant of
L. pneumophila
. In summary, the screen for amoeba-sensitive
Legionella
clones efficiently isolated mutants that do not grow in amoebae and, in the case of the
bdhA-patD
mutant, also human cells.
Selected
Pseudomonas putida
Strains Able To Grow in the Presence of High Butanol Concentrations
Authors: Rühl Jana , Schmid Andreas , Blank Lars Mathias
Published: May 2009

Adapted
Pseudomonas putida
strains grew in the presence of up to 6% (vol/vol) butanol, the highest reported butanol concentration tolerated by a microbe.
P
.
putida
might be an alternative host for biobutanol production, overcoming the primary limitation of currently used strains—insufficient product titers due to low butanol tolerance.
Regulation of the Display Ratio of Enzymes on the
Saccharomyces cerevisiae
Cell Surface by the Immunoglobulin G and Cellulosomal Enzyme Binding Domains
Authors: Ito Junji , Kosugi Akihiko , Tanaka Tsutomu , Kuroda Kouichi , Shibasaki Seiji , Ogino Chiaki , Ueda Mitsuyoshi , Fukuda Hideki , Doi Roy H. , Kondo Akihiko
Published: May 2009

We constructed a novel cell surface display system to control the ratio of target proteins on the
Saccharomyces cerevisiae
cell surface, using two pairs of protein-protein interactions. One protein pair is the Z domain of protein A derived from
Staphylococcus aureus
and the Fc domain of human immunoglobulin G. The other is the cohesin (Coh) and dockerin (Dock) from the cellulosome of
Clostridium cellulovorans
. In this proposed displaying system, the scaffolding proteins (fusion proteins of Z and Coh) were displayed on the cell surface by fusing with the 3′ half of α-agglutinin, and the target proteins fused with Fc or Dock were secreted. As a target protein, a recombinant
Trichoderma reesei
endoglucanase II (EGII) was secreted into the medium and immediately displayed on the yeast cell surface via the Z and Fc domains. Display of EGII on the cell surface was confirmed by hydrolysis of β-glucan as a substrate, and EGII activity was detected in the cell pellet fraction. Finally, two enzymes, EGII and
Aspergillus aculeatus
β-glucosidase 1, were codisplayed on the cell surface via Z-Fc and Dock-Coh interactions, respectively. As a result, the yeast displaying two enzymes hydrolyzed β-glucan to glucose very well. These results strongly indicated that the proposed strategy, the simultaneous display of two enzymes on the yeast cell surface, was accomplished by quantitatively controlling the display system using affinity binding.
Genomic and Biochemical Analysis of N Glycosylation in the Mushroom-Forming BasidiomyceteSchizophyllum commune
Authors: Berends Elsa , Ohm Robin A. , de Jong Jan F. , Rouwendal Gerard , Wösten Han A. B. , Lugones Luis G. , Bosch Dirk
Published: May 2009

N-linked glycans ofSchizophyllum communeconsist of Man5-9GlcNAc2structures. Lack of further glycan maturation is explained by the absence of genes encoding such functions in this and other homobasidiomycetes. N-linked glycans in vegetative mycelium and fruiting bodies ofS. communeare mainly Man7GlcNAc2and Man5GlcNAc2, respectively, suggesting more efficient mannose trimming in the mushroom.