bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forced‐response in online surveys: Bias from reactance and an increase in sex‐specific dropout
Authors: Stieger Stefan , Reips Ulf‐Dietrich , Voracek Martin 
Published: July 2007

AbstractDue to computer technology, a forced‐response can be easily achieved in online questionnaires and is frequently used to gather complete datasets. An Internet‐based quasi‐experiment was conducted on the student server at the University of Vienna to study the influence of forced‐response on dropout, demographic reports, and the content of the results. Forced‐response was shown to substantially increase dropout. In addition, forced‐response interacted with reported sex in eliminating a naturally occurring sex difference in dropout that was observed for the questionnaire whenever responses did not need to be enforced. Also reported sex turned out to have a mediating effect on time of dropout: Men dropped out earlier than did women. Further analyses revealed a reactance effect, as predicted by reactance theory. It is concluded that data from online questionnaires with forced‐response designs are in danger of being hampered by dropout and reactance.
Nitroxide radicals protect cultured rat embryos and yolk sacs from diabetic‐induced damage
Authors: Ryu Seonghun , Kohen Roni , Samuni Amram , Ornoy Asher 
Published: July 2007

AbstractBACKGROUND: Diabetic teratogenicity relates, partly, to embryonic oxidative stress and the extent of the embryonic damage can apparently be reduced by antioxidants. We investigated the effects of superoxide dismutase‐mimics nitroxides, 2,2,6,6‐tetramethyl piperidine‐N‐oxyl (TPL) as an effective antioxidant, on diabetes‐induced embryopathy. METHODS: Embryos (10.5 day old) and their yolk sacs from Sabra female rats were cultured for 28 h in the absence or in the presence of nitroxides at 0.05–0.4 mM in control, diabetic subteratogenic, or diabetic teratogenic media, and monitored for growth retardation and congenital anomalies. The oxidant/antioxidant status was examined by oxygen radical absorbance capacity and lipid peroxidation assays, whereas the yolk sac function was evaluated by endocytosis assay. RESULTS: Diabetic culture medium inhibited embryonic and yolk sac growth, induced a high rate of NTDs, reduced yolk sac endocytosis and embryonic antioxidant capacity, and increased lipid peroxidation. These effects were more prominent in the embryos with NTD compared to those without NTD. TPL added to diabetic teratogenic medium improved embryonic and yolk sac growth, reduced the rate of NTDs, and improved yolk sac function. The oxidant/antioxidant status of embryos was also improved. TPL at 1 mM did not damage the embryos cultured in control medium. CONCLUSIONS: In diabetic culture medium, oxidative damage is higher in the malformed rat embryos compared to those without anomalies; the nitroxide provides protection againstdiabetes‐induced teratogenicity in a dose‐dependent manner. The yolk sac damage, apparently caused by the same mechanism, might be an additional contributor to the embryonic damage observed in diabetes. Birth Defects Research (Part A), 2007. © 2007 Wiley‐Liss, Inc.
Zeolite‐based cataluminescence sensor for the selective detection of acetaldehyde
Authors: Yang Ping , Lau Choiwan , Liang Jian‐Ying , Lu Jian‐Zhong , Liu Xia 
Published: July 2007

AbstractThe reactions of acetaldehyde with O atoms in the cages of large‐pore zeolites have been discovered to result in light emission. The luminescence characteristics of acetaldehyde vapours passing through the surface of chosen zeolites were studied using a cataluminescence‐based detection system. To demonstrate the feasibility of the method, the detection of acetaldehyde using catalysts was studied systematically and a linear response of 0.06–31.2 µg/mL acetaldehyde vapour was obtained. Methanol, ethanol, isopropanol, methylbenzene, chloroform, dichlormethane and acetonitrile did not interfere with the determination of acetaldehyde. Acetaldehyde vapour could also be distinguished from some homologous series such as formaldehyde, cinnamaldehyde, glutaraldehyde and benzaldehyde on this catalyst, possibly due to the stereoselectivity of the zeolite and its specific reaction mechanism. Moreover, acetaldehyde was quantified without detectable interference from formaldehyde in four artificial samples. Thus, this kind of cataluminescence‐based sensor could be potentially extended to the analysis of volatile organic compounds in air, and the simple and portable properties of cataluminescence‐based sensors could also make them beneficial in many areas of analytical science. Copyright © 2007 John Wiley & Sons, Ltd.
Development of cell‐free protein synthesis platforms for disulfide bonded proteins
Authors: Goerke Aaron R. , Swartz James R. 
Published: July 2007

AbstractThe use of cell‐free protein synthesis (CFPS) for recombinant protein production is emerging as an important technology. For example, the openness of the cell‐free system allows control of the reaction environment to promote folding of disulfide bonded proteins in a rapid and economically feasible format. These advantages make cell‐free protein expression systems particularly well suited for producing patient specific therapeutic vaccines or antidotes in response to threats from natural and man‐made biological agents and for pharmaceutical proteins that are difficult to produce in living cells. In this work we assess the versatility of modern cell‐free methods, optimize expression and folding parameters, and highlight the importance of rationally designed plasmid templates for producing mammalian secreted proteins, fusion proteins, and antibody fragments in our E. coli‐based CFPS system. Two unique CFPS platforms were established by developing standardized extract preparation protocols and generic cell‐free reaction conditions. Generic reaction conditions enabled all proteins to express well with the best therapeutic protein yield at 710 µg/mL, an antibody fragment at 230 µg/mL, and a vaccine fusion protein at 300 µg/mL; with the majority correctly folded. Better yields were obtained when cell‐free reaction conditions were optimized for each protein. Establishing general CFPS platforms enhances the potential for cell‐free protein synthesis to reliably produce complex protein products at low production and capital costs with very rapid process development timelines. Biotechnol. Bioeng. 2008;99: 351–367. © 2007 Wiley Periodicals, Inc.
On‐line near infrared monitoring of glycerol‐boosted anaerobic digestion processes: Evaluation of process analytical technologies
Authors: Holm‐Nielsen Jens Bo , Lomborg Carina Juel , Oleskowicz‐Popiel Piotr , Esbensen Kim H. 
Published: July 2007

AbstractA study of NIR as a tool for process monitoring of thermophilic anaerobic digestion boosted by glycerol has been carried out, aiming at developing simple and robust Process Analytical Technology modalities for on‐line surveillance in full scale biogas plants. Three 5 L laboratory fermenters equipped with on‐line NIR sensor and special sampling stations were used as a basis for chemometric multivariate calibration. NIR characterisation using Transflexive Embedded Near Infra‐Red Sensor (TENIRS) equipment integrated into an external recurrent loop on the fermentation reactors, allows for representative sampling, of the highly heterogeneous fermentation bio slurries. Glycerol is an important by‐product from the increasing European bio‐diesel production. Glycerol addition can boost biogas yields, if not exceeding a limiting 5–7 g L−1 concentration inside the fermenter—further increase can cause strong imbalance in the anaerobic digestion process. A secondary objective was to evaluate the effect of addition of glycerol, in a spiking experiment which introduced increasing organic overloading as monitored by volatile fatty acids (VFA) levels. High correlation between on‐line NIR determinations of glycerol and VFA contents has been documented. Chemometric regression models (PLS) between glycerol and NIR spectra needed no outlier removals and only one PLS‐component was required. Test set validation resulted in excellent measures of prediction performance, precision: r2 = 0.96 and accuracy = 1.04, slope of predicted versus reference fitting. Similar prediction statistics for acetic acid, iso‐butanoic acid and total VFA proves that process NIR spectroscopy is able to quantify all pertinent levels of both volatile fatty acids and glycerol. Biotechnol. Bioeng. 2008;99: 302–313. © 2007 Wiley Periodicals, Inc.
Radial flow hepatocyte bioreactor using stacked microfabricated grooved substrates
Authors: Park Jaesung , Li Yawen , Berthiaume François , Toner Mehmet , Yarmush Martin L. , Tilles Arno W. 
Published: July 2007

AbstractBioartificial liver (BAL) devices with fully functioning hepatocytes have the potential to provide temporary hepatic support for patients with liver failure. The goal of this study was to optimize the flow environment for the cultured hepatocytes in a stacked substrate, radial flow bioreactor. Photolithographic techniques were used to microfabricate concentric grooves onto the underlying glass substrates. The microgrooves served to protect the seeded hepatocytes from the high shear stresses caused by the volumetric flow rates necessary for adequate convective oxygen delivery. Finite element analysis was used to analyze the shear stresses and oxygen concentrations in the bioreactor. By employing high volumetric flow rates, sufficient oxygen supply to the hepatocytes was possible without an integrated oxygen permeable membrane. To implement this concept, 18 microgrooved glass substrates, seeded with rat hepatocytes cocultured with 3T3‐J2 fibroblasts, were stacked in the bioreactor, creating a channel height of 100 µm between each substrate. In this bioreactor configuration, liver‐specific functions (i.e., albumin and urea synthesis rates) of the hepatocytes remained stable over 5 days of perfusion, and were significantly increased compared to those in the radial flow bioreactor with stacked substrates without microgrooves. This study suggests that this radial flow bioreactor with stacked microgrooved substrates is scalable and may have potential as a BAL device in the treatment of liver failure. Biotechnol. Bioeng. 2008;99: 455–467. © 2007 Wiley Periodicals, Inc.
Degradation of toluene by a mixed population of archetypal aerobes, microaerophiles, and denitrifiers: Laboratory sand column experiment and multispecies biofilm model formulation
Authors: Kim Hyun‐su , Jaffé Peter R. 
Published: July 2007

AbstractAn experiment was conducted in a saturated sand column with three bacterial strains that have different growth characteristics on toluene, Pseudomonas putida F1 which degrades toluene only under aerobic conditions, Thauera aromatica T1 which degrades toluene only under denitrifying conditions, and Ralstonia pickettii PKO1 has a facultative nature and can perform nitrate‐enhanced biodegradation of toluene under hypoxic conditions (DO <2 mg/L). Steady‐state concentration profiles showed that oxygen and nitrate appeared to be utilized simultaneously, regardless of the dissolved oxygen concentration and the results from fluorescent in‐situ hybridization (FISH) indicated that PKO1 maintained stable cells numbers throughout the column, even when the pore water oxygen concentration was high. Since PKO1's growth rate under aerobic condition is much lower than that of F1, except under hypoxic conditions, these observations were not anticipated. Therefore these observations require a mechanistic explanation that can account for localized low oxygen concentrations under aerobic conditions. To simulate the observed dynamics, a multispecies biofilm model was implemented. This model formulation assumes the formation of a thin biofilm that is composed of the three bacterial strains. The individual strains grow in response to the substrate and electron acceptor flux from bulk fluid into the biofilm. The model was implemented such that internal changes in bacterial composition and substrate concentration can be simulated over time and space. The model simulations from oxic to denitrifying conditions compared well to the experimental profiles of the chemical species and the bacterial strains, indicating the importance of accounting for the biological activity of individual strains in biofilms that span different redox conditions. Biotechnol. Bioeng. 2008;99: 290–301. © 2007 Wiley Periodicals, Inc.
Salt‐induced changes in plasmid DNA transmission through ultrafiltration membranes
Authors: Latulippe David R. , Zydney Andrew L. 
Published: July 2007

AbstractRecent studies have demonstrated the feasibility of using ultrafiltration for the purification of plasmid DNA, but there is still little understanding of the factors governing DNA transmission. Experimental data were obtained for the transmission of a 3.0 kbp supercoiled plasmid DNA through composite regenerated cellulose ultrafiltration membranes as a function of solution ionic environment in a stirred ultrafiltration cell. The dependence on salt concentration was quite dramatic, with the sieving coefficient increasing by more than 80‐fold as the NaCl concentration increased from 1 to 150 mM at a fixed filtrate flux. At the same total ionic strength, the sieving coefficient in an MgCl2 solution was significantly larger than that evaluated in NaCl. The sieving results are consistent with independent studies showing a reduction in the effective plasmid size due to salt specific shielding of intramolecular electrostatic interactions. DNA transmission was also a strong function of the filtrate flux, with negligible transmission below a critical value of the flux. The predicted values of the critical filtrate flux determined using a modified elongational flow model were in excellent agreement with the experimental data. These results clearly demonstrate that salt‐induced changes in plasmid DNA structure have a significant effect on plasmid DNA transmission through ultrafiltration membranes. Biotechnol. Bioeng. 2008;99: 390–398. © 2007 Wiley Periodicals, Inc.
Protein assembly onto patterned microfabricated devices through enzymatic activation of fusion pro‐tag
Authors: Lewandowski Angela T. , Yi Hyunmin , Luo Xiaolong , Payne Gregory F. , Ghodssi Reza , Rubloff Gary W. , Bentley William E. 
Published: July 2007

AbstractWe report a versatile approach for covalent surface‐assembly of proteins onto selected electrode patterns of pre‐fabricated devices. Our approach is based on electro‐assembly of the aminopolysaccharide chitosan scaffold as a stable thin film onto patterned conductive surfaces of the device, which is followed by covalent assembly of the target protein onto the scaffold surface upon enzymatic activation of the protein's “pro‐tag.” For our demonstration, the model target protein is green fluorescent protein (GFP) genetically fused with a pentatyrosine pro‐tag at its C‐terminus, which assembles onto both two‐dimensional chips and within fully packaged microfluidic devices in situ and under flow. Our surface‐assembly approach enables spatial selectivity and orientational control under mild experimental conditions. We believe that our integrated approach harnessing genetic manipulation, in situ enzymatic activation, and electro‐assembly makes it advantageous for a wide variety of bioMEMS and biosensing applications that require facile “biofunctionalization” of microfabricated devices. Biotechnol. Bioeng. 2008;99: 499–507. © 2007 Wiley Periodicals, Inc.
Differential organization of γ‐aminobutyric acid type A and glycine receptors in the somatic and dendritic compartments of rat abducens motoneurons
Authors: Lorenzo Louis‐Etienne , Russier Michaël , Barbe Annick , Fritschy Jean‐Marc , Bras Hélène 
Published: July 2007

AbstractPremotor inhibitory neurons responsible for the decrease in the firing discharge during fast or slow eye movements selectively target the cell bodies and the dendrites of abducens motoneurons. γ‐Aminobutyric acid (GABA) and glycine, the main inhibitory synaptic neurotransmitters in the central nervous system, act via glycine and GABAA receptors, assembled from various types of subunits, which determine the kinetics of the currents mediated. Therefore, our hypothesis was that the expression of the inhibitory receptors on the somatic and the dendritic compartments, involved in different functions, may differ. In this study, we compared the subcellular patterns of expression of the main GABAA receptor subunits (GABAARα1, α2, α3, α5), glycine receptors (GlyRα1), and gephyrin in the somatic and dendritic compartments of rat abducens motoneurons, using double or triple immunocytochemical experiments with confocal microscopy. Significant differences exist in the patterns of organization and the synaptic expression of the GlyR and GABAAR subunits in the cell bodies and dendrites of abducens motoneurons. In the somata, only the GABAARα1 subunit was expressed, whereas both GABAARα1 and GABAARα3 were present in the dendrites. The GlyRα1 to GABAARα1 density ratio was reversed in the somatic and dendritic compartments (0.9 vs. 2.3). A quantitative electron microscopy study showed that the modes whereby gephyrin reaches its postsynaptic inhibitory synaptic target differ between the somata and the dendrites. Therefore, our results support the idea that a structure‐function adaptation occurs at the single‐neuron level. J. Comp. Neurol. 504:112–126, 2007. © 2007 Wiley‐Liss, Inc.
Discharge Development in ac Plasma Displays
Authors: Röpcke J. , Zahn R.‐J. 
Published: July 2007

AbstractThe discharge development in ac plasma displays is quantitatively assessed on the basis of comparatively great data quantities under well defined parameter conditions by means of computer controlled equipment. Investigated are ac plasma displays of three different sizes: PAF 58, 90 and PAF 128.The development of an individual discharge in a stationary pulse sequence is described by analyzing the light emitted by the discharge and by comparing the data obtained with theoretical calculations.Essential characteristics of the pulsed light emission of an ac plasma display discharge are the build‐up time tA, i.e. the period from cell voltage switch‐on to the discharge maximum, and the characteristic time τ, which is the time constant describing the exponential growth of the discharge in its amplification range.The theoretical model shows the transition, during discharge build up, from directionization of neon atoms, mainly at low τ values, to ionization essentially via the Penning effect at high τ values. Therefore the effective Townsend ionization coefficient is dependent on τ. The measured time constants of the discharge build up are in good agreement with the calculated values. Adaption between measurement and calculation is achieved by variation of the secondary emission coefficient γ of the cathode.
Plasma‐Screening Effects upon Energy Levels and Electron Scattering from Neutral and Ionized Caesium
Authors: Chin Y. J. , Radtke R. , Zimmermann R. 
Published: July 2007

AbstractUsing interaction potentials screened with the Debye‐Hückel length, the effects of plasma shielding on energy levels and electrons scattering from neutral and ionized caesium are estimated. Both energy levels and atomic scattering cross‐sections are found to be sensitive to the inclusion of screening. Relating to the scattering by the Cs+ ion, a low‐energy resonance near E = 0.3 Ryd is found which arises from the f‐wave phase shift and reflects the individual behaviour of the scattering ion.
Properties of the Tokamak Edge Plasma
Authors: Wolff H. 
Published: July 2007

AbstractA short review of some features of the edge plasma in limiter tokamaks is given. The limits of the simple 1‐D SOL model and the relation between the core plasma are discussed. MARFE phenomena and detached plasma are closely connected with the particle and energy balance of the SOL. Their occurrence is based on the relation of plasma parameters of the edge plasma to those of the core. Important problems of plasma wall interactions are the detection of the impurity sources and sinks and the study of the impurity transport and shielding. The non‐uniform character of plasma wall interactions and their dependence on the discharge performance still renders difficult any theoretical forecast of impurity distribution and transport and calls for better diagnostics.
On the Temperature Dependence of Plasma Polymerization
Authors: Deutsch H. , Kersten H. , Klagge S. , Rutscher A. 
Published: July 2007

AbstractA simple model is developed to explain the measured temperature dependence of the growth rate of polymerfilms in a C6H6‐Ne‐glow discharge.The negative Arrhenius‐behaviour obtained that means a decreasing growth rate with increasing temperature — is determined by an adsorption‐desorption‐equilibrium of the monomer particles on the surface.From the fitting of the temperature behaviour experimentally obtained by probe measurements some characteristic parameters (activation energy, residence time) were calculated by means of the model.
Nonlinear Effects of a Gaussian Laser Beam on Megagauss Magnetic Field Generation in Laser Produced Plasma
Authors: Prabhakar M. V. H. V. , Srivastava M. P. 
Published: July 2007

AbstractThe generation of megagauss magnetic field due to the time dependent part of the ponderomotive force of a self‐focused Gaussian laser beam indicent on a plasma has been studied. Defocusing of the laser beam becomes possible due to diffraction divergence in the case of a weakly nonlinear medium. The influence of defocusing of a laser beam on magnetic field generation has also been investigated. It is found that the magnitude of the magnetic field due to self focusing of the beam is enhanced and is comparable with the observed values, while there is a reduction in the magnitude of the magnetic field when the beam defocuses due to diffraction divergence in the presence of weak nonlinearity.
Hollow Cathode Effect with Double Axial Electron Injection
Authors: Bratescu G. G. , Ciobotaru D. , Dima G. 
Published: July 2007

AbstractThe paper presents a new type of HCE glow discharge obtained with double plane‐conical cathodes. The two identical cathodes are tronconical and screened with 1 mm2 mailed wire net with a 3.5 mm diameter central washer each. The discharge is obtained between the two cathodes and a ring shaped anode equally distant from both. Optimum intercathodic span is 4 mm, allowing for maximum amplifications at the optimum pressure values for the two gases. Employed helium and argon are spectral pure. At the given distance and depending on voltage and gas pressure, a double axial electron self injection cathode effect is obtained between the electrodes, consisting of very large increase of current and radiations.
Experience with Measuring of the Spectral Line Profile by Means of the Fabry‐Perot Interferometer
Authors: Brablec A. , Kapicka V. , Stastny F. 
Published: July 2007

AbstractResults of plasma diagnostics by means of the Fabry‐Perot interferometer are very sensitive to a right adjustment, a choice of both the working diaphragm and exposition time, etc. Furthermore, a choice of adequate methods applied to the calculation of plasma parameters from experimental data is very important. As it is very difficult to verify the validity of measured results in this case, a sufficient attention was not given to these problems and at present we find only few really useful information in literature, which would correspond with conterporary level of technique. In this paper there is summarized our experience obtained during many years use of the Fabry‐Perot interferometer in plasma diagnostics.
The Hβ Line Dip Shift
Authors: Djurović S. , Mijatović Z. , Kobilarov R. 
Published: July 2007

AbstractThe Hβ line dip shift was measured and compared with experimental and theoretical results of the other authors. Our results are in a good agreement with the experimental results but in a disagreement or even discrepancy with GRIEM'S theory. Plasmas were produced in the wall stsbilized arc.