bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of magnetic field on electrical properties of nanocrystalline poly(vinylidene fluoride) samples
Authors: Shukla Prashant , Gaur Mulayam Singh 
Published: September 2009

AbstractBACKGROUND: The electrical properties of nanocrystalline poly(vinylidene fluoride) (PVDF) samples of 20 µm in thickness were measured in terms of thermally stimulated current (TSC), conduction current and dielectric constant after application of a magnetic field.RESULTS: TSC shows the release of trapped charges inside the material that enhances the current with magnetic field. The reason for the polarity reversal of the current with reversal of the magnetic field polarity is due to the change in spin of electrons depending upon the direction of the magnetic field.CONCLUSION: The magnetic field causes trapping of charge carriers in different traps, as the reason for the increase of activation energy with increasing field. The flow of conduction current at constant temperature in magnetically polarized PVDF is governed by Poole–Frenkel and Schottky–Richardson mechanisms. The decrease in dielectric constant at a certain alternating current (AC) frequency and magnetic field with temperature is caused by magnetic polarization in addition to the AC field. Copyright © 2009 Society of Chemical Industry
The effects of antiepileptic drugs on classroom performance
Authors: Titus Jeffrey B. , Thio Liu Lin 
Published: September 2009

AbstractEpilepsy is one of the most common neurological disorders in children, and it has been associated with an increased risk of cognitive, psychiatric, and learning problems. Although side effects of antiepileptic drugs (AEDs) have been long studied in adults, an understanding of how they manifest in children is only beginning to emerge. Careful clinical considerations must be made to accurately determine the potential contribution of AEDs to learning problems, and this includes understanding the complex role played by multiple medical, developmental, and psychosocial factors. The present review provides information on common cognitive and psychiatric side effects of AED treatment in children, with consideration of classroom accommodations and strategies that may be helpful to circumvent these difficulties. © 2009 Wiley Periodicals, Inc.
The properties of hub proteins in a yeast‐aggregated cell cycle network and its phase sub‐networks
Authors: Wu Xiaomei , Guo Jie , Zhang Da‐Yong , Lin Kui 
Published: September 2009

AbstractCurrently, most researches on the properties of interacting proteins, hubs in particular, are mainly based on an aggregated network of binary interactions. Here, by projecting a yeast‐aggregated cell cycle network into four phase (G1, S, G2 and M) sub‐networks, we explored the properties of the hubs of the aggregated network. We found, as expected that only 69% (103 of 149) of hubs still act as hubs in at least one of the four sub‐networks. Interestingly, those (19%) that are not hubs in any phase tend to perform multiple functions and differ from the others in their network positions. We also analyzed the potential biological features among the dynamic and static hubs. Finally, we investigated the dynamic properties of two complexes, the anaphase‐promoting complex and the chromatin‐remodeling complex. The dynamic function of the anaphase‐promoting complex is represented by its interactions with CDC28 at different stages of mitotic cell cycle. The chromatin‐remodeling complex is assembled when its dynamic component, ARP7, is periodically expressed in S phase to function in chromatin remodeling, which could reflect the just‐in‐time assembly of protein complexes. In conclusion, the study of decomposing the aggregated network and characterizing the hubs in decomposed sub‐networks is useful for further understanding the dynamic functions of yeast cell cycle.
Inoculation‐density‐dependent responses and pathway shifts in Saccharomyces cerevisiae
Authors: Cheng Jing‐Sheng , Ding Ming‐Zhu , Tian Hong‐Chi , Yuan Ying‐Jin 
Published: September 2009

AbstractThe cell‐density‐dependent responses of Saccharomyces cerevisiae to inoculation sizes were explored by a proteomic approach. According to their gene ontology, 100 protein spots with differential expression, corresponding to 67 proteins, were identified and classed into 17 different functional groups. Upregulation of eight heat shock, oxidative response and amino acid biosynthesis‐related proteins (e.g. Hsp78p, Ssa1p, Hsp60p, Ctt1p, Sod1p, Ahp1p, Met6p and Met17p), which may jointly maintain the cell redox homeostasis, was dependant on inoculation density. Significant increases in the levels of five proteins involved in glycolysis and alcohol biosynthesis pathways (e.g. Glk1p, Fba1p, Eno1p, Pdc1p and Adh1p) might play critical roles in improving ethanol productivity of the fermentation process and shortening the fermentation time when inoculation sizes were increased. Cell‐density‐dependent glycolytic variations of proteins involved in trehalose, glycerol biosynthesis and pentose phosphate pathway revealed shifts among metabolic pathways during fermentation with different inoculation sizes. Upregulation of three signal transduction proteins (Bmh1p, Bmh2p and Fpr1p) indicated that adequate cell–cell contacts improved cellular communication at high inoculation sizes. These findings provide insights into yeast responses to inoculation size and optimizing the direct inoculation of active dry yeast fermentation, so as to improve the ethanol production.
Yeast proteome map (last update)
Authors: Perrot Michel , Moes Suzette , Massoni Aurélie , Jenoe Paul , Boucherie Hélian 
Published: September 2009

AbstractThe identification of proteins separated on 2‐D gels is essential to exploit the full potential of 2‐D gel electrophoresis for proteomic investigations. For this purpose we have undertaken the systematic identification of Saccharomyces cerevisiae proteins separated on 2‐D gels. We report here the identification by mass spectrometry of 100 novel yeast protein spots that have so far not been tackled due to their scarcity on our standard 2‐D gels. These identifications extend the number of protein spots identified on our yeast 2‐D proteome map to 716. They correspond to 485 unique proteins. Among these, 154 were resolved into several isoforms. The present data set can now be expanded to report for the first time a map of 363 protein isoforms that significantly deepens our knowledge of the yeast proteome. The reference map and a list of all identified proteins can be accessed on the Yeast Protein Map server (www.ibgc.u‐bordeaux2.fr/YPM).
Dispersion interactions in density‐functional theory
Authors: Johnson Erin R. , Mackie Iain D. , DiLabio Gino A. 
Published: September 2009

AbstractDensity‐functional theory (DFT) allows for the calculation of many chemical properties with relative ease, thus making it extremely useful for the physical organic chemistry community to understand and focus on various experiments. However, density‐functional techniques have their limitations, including the ability to satisfactorily describe dispersion interactions. Given the ubiquitous nature of dispersion in chemical and biological systems, this is not a trivial matter. Recent advances in the development of DFT methods can treat dispersion. These include dispersion‐corrected DFT (using explicit, attractive dispersion terms), parameterized functionals, and dispersion‐correcting potentials, all of which can dramatically improve performance for dispersion‐bound species. In this perspective, we highlight the achievements made in modeling dispersion using DFT. We hope that this will provide valuable insight to both computational chemists and experimentalists, who aim to study physical processes driven by dispersion interactions. Copyright © 2009 John Wiley & Sons, Ltd.
Enols of 2‐nitro‐ and related 2‐substituted malonamides
Authors: Basheer Ahmad , Mishima Masaaki , Rappoport Zvi 
Published: September 2009

AbstractThe structures of 2‐substituted malonamides, YCH(CONR1R2)CONR3R4 (Y = Br, SO2Me, CONH2, COMe, and NO2) were investigated. When Y = Br, R1R2 = R3R4 = HEt; Y = SO2Me, R1–R4 = H and for Y = CONH2 or CONHPh, R1–R4 = Me, the structure in solution is that of the amide tautomer. X‐ray crystallography shows solid‐state amide structures for Y = SO2Me or CONH2, R1–R4 = H. Nitromalonamide displays an enol structure in the solid state with a strong hydrogen bond (O…O distance = 2.3730 Å at 100 K) and d(OH) ≠ d(O…H). An apparently symmetric enol was observed in solution, even in appreciable percentages in highly polar solvents such as DMSO‐d6, but Kenol values decrease on increasing the solvent polarity. The N,N′‐dimethyl derivative is less enolic. Acetylmalonamides display a mixture of enol on the acetyl group and amide in non‐polar solvents, and only the amide in DMSO‐d6. DFT calculations gave the following order of pKenol values for Y: H > CONH2 > COMe ≥ COMe (on acetyl) ≥ MeSO2 > CN > NO2 in the gas phase, CHCl3, and DMSO. The enol on the CO group is preferred to the aci‐nitro compound, and the NOH…OC is less favored than the COH…OC hydrogen bond. Copyright © 2009 John Wiley & Sons, Ltd.
The Role of Surface Chemistry at Ceramic/Electrolyte Interfaces in the Generation of Pulsed Corona Discharges in Water Using Porous Ceramic‐Coated Rod Electrodes
Authors: Lukes Petr , Clupek Martin , Babicky Vaclav , Sunka Pavel 
Published: September 2009

AbstractEffects associated with the electrical breakdown of water using porous ceramic‐coated rod electrodes were investigated for two types of ceramics, oxide (corundum) and silicates (almandine). Properties of the ceramic layer and its interaction with the electrolyte were found as important factors in the generation of electrical discharges in water. Initiation of the discharge depended not only on the permittivity and porosity of the ceramic, but also the surface charge formed on the ceramic, which was determined by the polarity of the applied voltage, and the pH and chemical composition of aqueous solution. An electrical double layer associated with the buildup of surface charge at ceramic/electrolyte interface affected the electric field distribution on the ceramic electrode. Using monopolar high voltage pulses, this layer became polarized, which, under certain experimental conditions, eventually quenched the electrical discharge in water. Applying bipolar pulses eliminated these effects.magnified image
Influence of Substrate Biasing on the Structural and Electrical Properties of Sputtered Zirconia Thin Films
Authors: Rebib Farida , Bousquet Angélique , Tomasella Eric , Micheli Victor , Gottardi Gloria , Laidani Nadhira 
Published: September 2009

AbstractZrOx thin films were deposited by sputtering a pure zirconia target under argon–oxygen atmosphere and soft conditions: low substrate temperature and applied power. An anode biasing was added for different time durations in order to modify the substrate/layer interface. Auger profiling showed a sub‐stochiometric character that increases with the ion bombardment. The latter treatment led to the formation of an oxygen rich interface. XPS analysis revealed that all the zirconium was bonded to oxygen. Moreover, using the energy loss from the O 1s photoelectron signal, the optical band gap was found to increase with the biasing time. Capacitance–voltage measurement showed a high dielectric constant for all the deposits and defect formation in the film bulk when the ion bombardment was added during the layer growth.
Evolving understanding of the evolution of herbicide resistance
Authors: Gressel Jonathan 
Published: September 2009

AbstractA greater number of, and more varied, modes of resistance have evolved in weeds than in other pests because the usage of herbicides is far more extensive than the usage of other pesticides, and because weed seed output is so great. The discovery and development of selective herbicides are more problematic than those of insecticides and fungicides, as these must only differentiate between plant and insect or pathogen. Herbicides are typically selective between plants, meaning that before deployment there are already some crops possessing natural herbicide resistance that weeds could evolve. The concepts of the evolution of resistance and the mechanisms of delaying resistance have evolved as nature has continually evolved new types of resistance. Major gene target‐site mutations were the first types to evolve, with initial consideration devoted mainly to them, but slowly ‘creeping’ resistance, gradually accruing increasing levels of resistance, has become a major force owing to an incremental accumulation of genetic changes in weed populations. Weeds have evolved mechanisms unknown even in antibiotic as well as other drug and pesticide resistances. It is even possible that cases of epigenetic ‘remembered’ resistances may have appeared. Copyright © 2009 Society of Chemical Industry
Mechanical relaxation in tetragonal and orthorhombic phases of (Ba,Sr)TiO3 ceramics
Authors: Wang H. Y. , Chen L. , Meng H. , Xiong X. M. , Zhang J. X. 
Published: September 2009

AbstractTwo broad relaxation peaks in the tetragonal and orthorhombic phases, respectively, of BaxSr1–xTiO3 (x = 0.8 and 1) ceramics were investigated via internal friction and modulus measurements. The activation energy calculated from the Arrhenius relation shows that the relaxation process depends on the thermal history. A possible explanation is proposed that the relaxation during heating is associated with the motion of domain walls, the migration of oxygen vacancies and the interaction between oxygen vacancies and domain walls. In addition, the activation energies of Ba0.8Sr0.2TiO3 are smaller than those of BaTiO3, possibly resulting from the larger interspaces of the two neighbouring Ba2+ and Sr2+ along the c‐axis.
Cooling‐field dependence of exchange bias and asymmetric reversal modes in a nanoparticles system with ferromagnetic core and antiferromagnetic matrix morphology
Authors: Hu Yong , Du An 
Published: September 2009

AbstractInterest in exchange bias (EB) in magnetic nanoparticles has increased in the past few years by virtue of its potential for application in fields such as ultrahigh‐density magnetic recording. A modified Monte Carlo Metropolis method is performed to simulate the effect of cooling field on EB and asymmetric reversal modes of a granular system of ferromagnetic (FM) nanoparticles embedded in an antiferromagnetic (AFM) matrix, based on three‐dimensional classical Heisenberg model. The results show that the EB first decreases slightly due to the energy barriers in the antiferromagnet, while the coercivity and vertical magnetization shift increase with the increase of cooling field, finally, they all level off as the cooling field is strong enough. Whereas the cooling‐ and measuring‐field angular dependence of asymmetric reversal modes reveal asymmetric reversal mechanism and interesting rotation process of FM spins, confirming the existence of the net magnetization on the surface of AFM matrix. The reason may be due to the energy competition and geometric frustration of system. However, the strong interfacial coupling may change the intrinsic atomic configuration of antiferromagnet to influence the EB and reversal modes.
Engineering of the Fluorescent‐Energy‐Conversion Arm of Phi29 DNA Packaging Motor for Single‐Molecule Studies
Authors: Lee Tae Jin , Zhang Hui , Chang Chun‐Li , Savran Cagri , Guo Peixuan 
Published: September 2009

AbstractThe bacteriophage phi29 DNA packaging motor contains a protein core with a central channel comprising twelve copies of re‐engineered gp10 protein geared by six copies of packaging RNA (pRNA) and a DNA packaging protein gp16 with unknown copies. Incorporation of this nanomotor into a nanodevice would be beneficial for many applications. To this end, extension and modification of the motor components are necessary for the linkage of this motor to other nanomachines. Here the re‐engineering of the motor DNA packaging protein gp16 by extending its length and doubling its size using a fusion protein technique is reported. The modified motor integrated with the eGFP‐gp16 maintains the ability to convert the chemical energy from adenosine triphosphate (ATP) hydrolysis to mechanical motion and package DNA. The resulting DNA‐filled capsid is subsequently converted into an infectious virion. The extended part of the gp16 arm is a fluorescent protein eGFP, which serves as a marker for tracking the motor in single‐molecule studies. The activity of the re‐engineered motor with eGFP‐gp16 is also observed directly with a bright‐field microscope via its ability to transport a 2‐µm‐sized cargo bound to the DNA.
Laser therapy of twin‐to‐twin transfusion syndrome in triplet pregnancies
Authors: Diemert A. , Diehl W. , Huber A. , Glosemeyer P. , Hecher K. 
Published: September 2009

AbstractObjectiveLaser coagulation of placental anastomoses in twin pregnancies complicated by severe twin‐to‐twin transfusion syndrome (TTTS) has been shown to be superior to serial amniodrainage, and has emerged as the standard therapy for this condition. We report the outcome of triplet pregnancies treated with laser therapy for severe TTTS.MethodsFrom a database containing information on all multiple pregnancies referred to our center we identified 20 triplet pregnancies with severe TTTS. Sixteen of them were dichorionic, four monochorionic and all cases were triamniotic. Perinatal outcome was obtained in all cases.ResultsFetoscopy was performed in 18 out of 20 cases at a median gestational age of 19.7 (range, 17.0–23.3) weeks. Delivery occurred at a median of 31.9 (range, 24.7–36.4) weeks with an overall fetal survival rate of 65%, at least one surviving fetus in 83% of cases and all three fetuses surviving in 39%.ConclusionLaser coagulation is an effective treatment for severe TTTS in triplets. However, survival rates are lower than in twin pregnancies. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Wind climate from the regional climate model REMO
Authors: Larsén Xiaoli Guo , Mann Jakob , Berg Jacob , Göttel Holger , Jacob Daniela 
Published: September 2009

AbstractSelected outputs from simulations with the regional climate model REMO from the Max Planck Institute, Hamburg, Germany were studied in connection with wind energy resource assessment. It was found that the mean wind characteristics based on observations from six mid‐latitude stations are well described by the standard winds derived from the REMO pressure data. The mean wind parameters include the directional wind distribution, directional and omni‐directional mean values and Weibull fitting parameters, spectral analysis and interannual variability of the standard winds. It was also found that, on average, the wind characteristics from REMO are in better agreement with observations than those derived from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) re‐analysis pressure data. The spatial correlation of REMO surface winds in Europe is consistent with that of the NCEP/NCAR surface winds, as well as published observations over Europe at synoptic scales. Therefore, REMO outputs are well suited for wind energy assessment application in Northern Europe. Copyright © 2009 John Wiley & Sons, Ltd.
Systematic Review and Meta‐Analysis of Chewing‐Gum Therapy in the Reduction of Postoperative Paralytic Ileus Following Gastrointestinal Surgery
Authors: Fitzgerald J. Edward F. , Ahmed Irfan 
Published: September 2009

AbstractBackgroundPostoperative ileus has long been considered an inevitable consequence of gastrointestinal surgery. It prolongs hospital stay, increases morbidity, and adds to treatment costs. Chewing is a form of sham feeding reported to stimulate bowel motility. This analysis examines the value of chewing‐gum therapy in treatment of postoperative ileus.MethodsA search for randomized, controlled trials studying elective gastrointestinal surgery was undertaken using MEDLINE, Embase, Cochrane Controlled Trials Register, and reference lists. Outcomes were extracted including time to first flatus and bowel motion, length of stay, and complications. Statistical analysis was undertaken using the weighted mean difference (WMD) and random‐effects model with 95% confidence intervals (CI).ResultsSeven studies with 272 patients were included. For time to first flatus the analysis favored treatment with a WMD of 12.6 h (17%) reduction (95% CI −21.49 to −3.72; P = 0.005). For time to first bowel motion, treatment was favored with a WMD of 23.11 h (22%) reduction (95% CI −34.32 to −11.91; P < 0.001). For length of stay, the analysis showed a nonsignificant trend toward treatment with WMD of 23.88 h (12%) reduction (95% CI −53.29 to +5.53; P = 0.11). There were no significant differences in complication rates.ConclusionsChewing‐gum therapy following open gastrointestinal surgery is beneficial in reducing the period of postoperative ileus, although without a significant reduction in length of hospital stay. These outcomes are not significant for laparoscopic gastrointestinal surgery.
Simple Methods to Detect Triacylglycerol Biosynthesis in a Yeast‐Based Recombinant System
Authors: Siloto Rodrigo M. P. , Truksa Martin , He Xiaohua , McKeon Thomas , Weselake Randall J. 
Published: September 2009

AbstractStandard methods to quantify the activity of triacylglycerol (TAG) synthesizing enzymes DGAT and PDAT (TAG‐SE) require a sensitive but rather arduous laboratory assay based on radio‐labeled substrates. Here we describe two straightforward methods to detect TAG production in baker's yeast Saccharomyces cerevisiae. First we demonstrate that a quadruple knockout yeast strain deficient in storage lipids has a reduced growth rate in a medium supplemented with fatty acids. This phenotype is rescued by restoring TAG biosynthesis and can be thus used to select yeast cells expressing a recombinant TAG‐SE. In the second method, the activity of the recombinant enzyme is measured in a fluorescent in situ assay using Nile red dye that is specific for neutral lipids. Correlation between Nile red fluorescence and enzyme activity is demonstrated with several mutants of a TAG synthesizing enzyme. This yeast live‐cell‐based assay is rapid, inexpensive, sensitive, and is amenable to high‐throughput applications. The methods can be used for a variety of applications such as isolation of novel genes, directed evolution, gene‐specific drug screening and will facilitate novel approaches in the research of TAG‐SE.
The Effect of Phospholipids on Butter Physical and Sensory Properties
Authors: Fedotova Yuliya , Lencki Robert W. 
Published: September 2009

AbstractThe addition of phospholipids (PL), either in the form of the milk fat globule membrane (MFGM) or soy lecithin, had a significant influence on butterfat crystal morphology. At low concentrations, PL addition increased spherulite size, but as PL levels reached 2 wt%, spherulite formation was inhibited and the microstructure consisted of well dispersed individual crystals. This change in crystal structure made the butter harder, less grainy at low temperatures, and less prone to oiling‐off above room temperature. PL addition was also shown to affect the relative concentrations of the various species created during crystallization. Of the two 2L β′ species that form at crystallization onset, the presence of PL shifted the balance towards the first species at the expense of the second. PL also facilitated the polymorphic transition of the 3L α species to a 2L β′ structure. It is unclear, however, whether the inhibition of spherulite formation was due directly to the inhibition of secondary nucleation by PL at the crystal surface, or indirectly by the reduction of supercooling resulting from a more rapid polymorphic transition. Evidently, PL concentration must be properly controlled during manufacturing in order to optimize butter functional properties.