bluuebunny/crossref_metadata_2025 huggingface dataset:
In situ cross‐linking of the shell of self‐assembled peptide nanotubes
Authors: Gokhale Rhishikesh , Couet Julien , Biesalski Markus
Published: March 2010

Peptide polymer nanotubes (PPNTs) were prepared by in situ surface‐initiated atom transfer radical polymerization (ATRP) from self‐assembled cyclic peptide nanotubes. PPNT dimensions, i.e., height (i.e. diameter) and length, as derived from AFM measurements of surface‐adsorbed, dry PPNT are a function of the molar mass of the peptide‐attached polymer molecules, and the overall structure is determined by subtle interplay of peptide–peptide and polymer–polymer interactions. As shown in previous communications, a PPNT length reduction occurs with increasing grafted mass of polymer chains. The latter may be attributed to strong segment–segment interactions of the nanotube‐grafted macromolecules. Here, we introduce a possible strategy to chemically stabilize PPNT. Peptide‐polymer nanotubes are prepared by in situ cross‐linking of the polymeric shell using the bi‐functional monomer ethylene glycol dimethacrylate (EGDMA) during surface‐initiated polymerization. PEGDMA‐PPNTs were characterized with respect to chemical identity, chemical stability and structure in the dry state, using FTIR, dissolution assays, and atomic force microscope (AFM) cross‐section analysis, respectively. The use of the cross‐linkable monomer yields chemically stable rigid‐rod like hybrid materials, where the overall length of the nano‐objects remains at a constant value of about 100 nm regardless of the adsorbed mass of the nanotube‐surrounding polymer material.
Capacitive electrolyte–insulator–semiconductor structures functionalised with a polyelectrolyte/enzyme multilayer: New strategy for enhanced field‐effect biosensing
Authors: Abouzar Maryam H. , Poghossian Arshak. , Siqueira José R. , Oliveira Osvaldo N. , Moritz Werner , Schöning Michael J.
Published: March 2010

A novel strategy for enhanced field‐effect biosensing using capacitive electrolyte–insulator–semiconductor (EIS) structures functionalised with pH‐responsive weak polyelectrolyte/enzyme or dendrimer/enzyme multilayers is presented. The feasibility of the proposed approach is exemplarily demonstrated by realising a penicillin biosensor based on a capacitive p‐Si–SiO2 EIS structure functionalised with a poly(allylamine hydrochloride) (PAH)/penicillinase and a poly(amidoamine) dendrimer/penicillinase multilayer. The developed sensors response to changes in both the local pH value near the gate surface and the charge of macromolecules induced via enzymatic reaction, resulting in a higher sensitivity. For comparison, an EIS penicillin biosensor with adsorptively immobilised penicillinase has been also studied. The highest penicillin sensitivity of 100 mV/dec has been observed for the EIS sensor functionalised with the PAH/penicillinase multilayer. The lower and upper detection limit was around 20 µM and 10 mM, respectively. In addition, an incorporation of enzymes in a multilayer prepared by layer‐by‐layer technique provides a larger amount of immobilised enzymes per sensor area, reduces enzyme leaching effects and thus, enhances the biosensor lifetime (the loss of penicillin sensitivity after 2 months was 10–12%).
Molecular rectification in metal–bridge molecule–metal junctions
Authors: Liu Yaqing , Offenhäusser Andreas , Mayer Dirk
Published: March 2010

Molecular bridged nanocontacts allow direct electrical addressing of electroactive molecules, which is of interest for the development of molecular based electronic devices. In the present paper, the electroactive molecule 6‐ferrocenyl‐1‐hexanethiol (Fc‐HT) was integrated into metal–bridge–metal (MBM) junctions assembled in a scanning tunneling microscope (STM) setup. A diode‐like behavior was observed from the current/bias (It/Vb) signal through Au (substrate)/Fc‐HT/Au (tip) junction, which presented an asymmetric current response due to the resonant tunneling between metal electrode and ferrocenylthiol molecules. With gate electrode modulation, the enhancement of the tunneling current can be controlled, which allows to tune the direction of the current rectification. Our investigations demonstrated that ferrocenylthiol bridged MBM nanostructure has potential applications in the future design of higher‐order heterojunctions components in combination with electrochemical logic gates.
Comprehensive plasma‐screening for known and unknown substances in doping controls
Authors: Thomas Andreas , Guddat Sven , Kohler Maxie , Krug Oliver , Schänzer Wilhelm , Petrou Michael , Thevis Mario
Published: March 2010

Occasionally, doping analysis has been recognized as a competitive challenge between cheating sportsmen and the analytical capabilities of testing laboratories. Both have made immense progress during the last decades, but obviously the athletes have the questionable benefit of frequently being able to switch to new, unknown and untested compounds to enhance their performance. Thus, as analytical counteraction and for effective drug testing, a complementary approach to classical targeted methods is required in order to implement a comprehensive screening procedure for known and unknown xenobiotics. The present study provides a new analytical strategy to circumvent the targeted character of classical doping controls without losing the required sensitivity and specificity. Using 50 µL of plasma only, the method potentially identifies illicit drugs in low ng/mL concentrations. Plasma provides the biological fluid with the circulating, unmodified xenobiotics; thus the identification of unknown compounds is facilitated. After a simple protein precipitation, liquid chromatographic separation and subsequent detection by means of high resolution/high accuracy orbitrap mass spectrometry, the procedure enables the determination of numerous compounds from different classes prohibited by the World Anti‐Doping Agency (WADA). A new hyphenated mass spectrometry technology was employed without precursor ion selection for higher collision energy dissociation (HCD) fragmentation experiments. Thus the mass spectra contained all the desired information to identify unknown substances retrospectively. The method was validated for 32 selected model compounds for qualitative purposes considering the parameters specificity, selectivity, limit of detection (<0.1–10 ng/mL), precision (9–28%), robustness, linearity, ion suppression and recovery (80–112%). In addition to the identification of unknown compounds, the plasma samples were simultaneously screened for known prohibited targets. Copyright © 2010 John Wiley & Sons, Ltd.
Production and isolation of ligated metal(IV)‐oxo ions by tandem mass spectrometry
Authors: Taylor Ivan F. , Blanksby Stephen J. , Colbran Stephen B. , Willett Gary D.
Published: March 2010

High valent metal(IV)‐oxo species, [M(O)(MeIm)n(OAc)]+ (M = Mn–Ni, MeIm = 1‐methylimidazole, n = 1–2), which are relevant to biology and oxidative catalysis, were produced and isolated in gas‐phase reactions of the metal(II) precursor ions [M(MeIm)n(OAc)]+ (M = Mn–Zn, n = 1–3) with ozone. The precursor ions [M(MeIm)(OAc)]+ and [M(MeIm)2(OAc)]+ were generated via collision‐induced dissociation of the corresponding [M(MeIm)3(OAc)]+ ion. The dependence of ozone reactivity on metal and coordination number is discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Surface‐activated chemical ionization time‐of‐flight mass spectrometry and labeling‐free approach: two powerful tools for the analysis of complex plant functional proteome profiles
Authors: Finiguerra Alessandro , Spadafora Antonia , Filadoro Dina , Mazzuca Silvia
Published: March 2010

Surface‐activated chemical ionization (SACI) has been widely used in recent years to analyze a range of different compounds (e.g., peptides, street drugs, amino acids). The main benefits of this technology are its high sensitivity and its effectiveness under different chromatographic conditions. Here, we used SACI in conjunction with a highly selective quadrupole time‐of‐flight mass analyzer to characterize a complex proteome pattern after separation by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE). The data obtained were compared with those obtained using the micro‐electrospray ionization (ESI) approach, which showed that using SACI strongly increased the number of detectable proteins. The higher sensitivity is mainly due to the ability of SACI to selectively produce singly charged species of high intensity under full‐scan conditions and doubly charged species for tandem mass spectrometric (MS/MS) peptide characterization by simply changing the ionization conditions during data acquisition. Copyright © 2010 John Wiley & Sons, Ltd.
Stable ion complexes of vitamin A species (retinol) in solution as detected by mass spectrometry
Authors: Sánchez‐Guijo Alberto , Montero Olimpio
Published: March 2010

Mechanisms of retinol (ROL) transport in plasma alternative to that involving the Retinol‐Binding Protein (RBP) have been hypothesized after RBP‐knockout mice were shown to be viable and fertile. Accordingly, the possibility of a ROL fraction circulating free in plasma has been suggested. In this study, stable complex formation between ROL and the physiological relevant ions Na+, Li+, and K+ was investigated by using mass spectrometry and assessed in regard to the aforementioned alternative mechanism. The ROL‐Na complex was found to be kinetically favoured with respect to the ROL‐Li and ROL‐K complexes. Fragmentation of the [ROL‐Na]+ adduct rendered the carbocation [ROL+H–H2O]+ (m/z 269) and NaOH as neutral loss. In consonance with these results, it is hypothesized on the possibility of the complex [ROL‐Na]+ being an alternative way of ROL transport to cells, as well as an intermediate in cis/trans isomerism. Copyright © 2010 John Wiley & Sons, Ltd.
Direct quantification of 11‐nor‐Δ9‐tetrahydrocannabinol‐9‐carboxylic acid in urine by liquid chromatography/tandem mass spectrometry in relation to doping control analysis
Authors: Chebbah C. , Pozo O. J. , Deventer K. , Van Eenoo P. , Delbeke F. T.
Published: March 2010

An accurate and precise method for the quantification of 11‐nor‐Δ9‐tetrahydrocannabinol‐9‐carboxylic acid (THCA) in urine by liquid chromatography/tandem mass spectrometry (LC/MS/MS) for doping analysis purposes has been developed. The method involves the use of only 200 µL of urine and the use of D9‐THCA as internal standard. No extraction procedure is used. The urine samples are hydrolysed using sodium hydroxide and diluted with a mixture of methanol/glacial acetic acid (1:1). Chromatographic separation is achieved using a C8 column with gradient elution. All MS and MS/MS parameters were optimised in both positive and negative electrospray ionisation modes. For the identification and the quantification of THCA three product ions are monitored in both ionisation modes. The method is linear over the studied range (5–40 ng/mL), with satisfactory intra‐and inter‐assay precision, and the relative standard deviations (RSDs) are lower than 15%. Good accuracy is achieved with bias less than 10% at all levels tested. No significant matrix effects are observed. The selectivity and specificity are satisfactory, and no interferences are detected. The LC/MS/MS method was applied for the analysis of 48 real urine samples previously analysed with a routine gas chromatography/mass spectrometry (GC/MS) method. A good correlation between the two methods was obtained (r2 > 0.98) with a slope close to 1. Copyright © 2010 John Wiley & Sons, Ltd.
Gas‐fragmentation study of the novel synthetic zwitterionic drug 3‐methyl‐9‐(2‐oxa‐2λ5‐2H‐1,3,2‐oxazaphosphorine‐2‐cyclohexyl)‐3,6,9‐triazaspiro[5,5]undecane chloride (SLXM‐2) by electrospray ionization tandem mass spectrometry
Authors: Wang Siting , Song Yan , Wang Jiao , Ling Xiaomei , Ge Zemei , Li Runtao , Cui Jingrong
Published: March 2010

The zwitterionic drug 3‐methyl‐9‐(2‐oxa‐2λ5‐2H‐1,3,2‐oxazaphosphorine‐2‐cyclohexyl)‐3,6,9‐triazaspiro[5,5]undecane chloride (SLXM‐2) is a novel synthetic compound which has shown anticancer activity and low toxicity in vivo. In this study, the various gas‐phase fragmentation routes were analyzed by electrospray ionization mass spectrometry (positive ion mode) in conjunction with tandem mass spectrometry (ESI‐MSn) for the first time. In ESI‐MS the fragment ion at m/z 289 (base peak) was formed by loss of the chlorine anion from the zwitterionic precursor SLXM‐2. The fragment ion at m/z 232 was formed from the ion at m/z 289 by loss of 1‐methylaziridine. The detailed gas‐phase collision‐induced dissociation (CID) fragmentation mechanisms obtained from the various precursor ions extracted from the zwitterionic SLXM‐2 drug was obtained by tandem mass spectrometry analyses. Copyright © 2010 John Wiley & Sons, Ltd.
Characterization of complex assemblages of organic acids in geological samples by negative electrospray ionization mass spectrometry using a double‐focusing magnetic sector field mass spectrometer
Authors: Pötz Stefanie , Wilkes Heinz , Witt Matthias , Horsfield Brian
Published: March 2010

Four different geological sample types (a crude oil, a crude oil asphaltene, a reservoir core extract and a reservoir core asphaltene) have been characterized by negative ionization electrospray mass spectrometry at low and high mass resolution using a double‐focusing magnetic sector field mass spectrometer. The mass range, shape of the spectra and the signal distribution of the acidic constituents as well as the average molecular weights, the total ion abundance and signal intensity in the spectra were compared for the different sample types. Nominal mass classes have been evaluated and Kendrick mass plots were generated in order to identify homologous series. For the crude oil sample, accurate mass assignments were made by high‐resolution double‐focusing magnetic sector field mass spectrometry (DFMSFMS) and were compared with those obtained by negative ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). With both instrument types, compounds with the molecular composition CnH2n+zO2, among which carboxylic acids predominated, were the main acidic compound class detectable in negative ESI mass spectra. Good agreement was achieved for the double bond class distribution and the carbon number distribution of the O2 class. In addition, minor compound classes could be identified using FTICRMS. Copyright © 2010 John Wiley & Sons, Ltd.
Exploring rearrangements along the fragmentation of glutaric acid negative ion: a combined experimental and theoretical study
Authors: Kanawati Basem , Schmitt‐Kopplin Philippe
Published: March 2010

Glutaric acid, a common short‐chain aliphatic dicarboxylic acid, was investigated in the negative ion mode by subjecting its [M–H]− ion to collision‐induced dissociation (CID) experiments in an infinity ion cyclotron resonance (ICR) cell coupled to a hexapole–quadrupole–hexapole ion guide. A 12 Tesla magnet was used for high‐resolution measurements. Two distinctive main pathways were observed in the MS/MS spectrum. The fragmentation pathways were also thoroughly investigated in a density functional theory (DFT) study involving a B3LYP/6‐311+G(2d,p)//B3LYP/6‐311+G(d,p) level of theory. Elimination of CO2 from the [M–H]− ion of the dicarboxylic acid takes place in a concerted mechanism, by which a 1,5 proton shift occurs from the intact carboxyl group to the methylene moiety located in the α position relative to the deprotonated carboxyl group. This concerted mechanism stabilizes the terminal negative charge and deprotonates the second carboxylic acid group. Water elimination from the [M–H]− ion does not take place by means of a simple proton removal from the α methylene group – and OH− release from the carboxylate group to abstract an additional α proton thus leading to the formation of a deprotonated ketene anion. In the case of this dicarboxylic acid, a new mechanism was found for water elimination, which differs from that known for aliphatic monocarboxylic acids. An intramolecular interaction between the deprotonated and the intact carboxyl groups plays a key role in making a new energetically favourable mechanism. The DFT study also reveals that a combined loss of CO2 and H2O in the form of H2CO3 is possible. Copyright © 2010 John Wiley & Sons, Ltd.
The performance implications of intra‐ and inter‐regional geographic diversification
Authors: Qian Gongming , Khoury Theodore A. , Peng Mike W. , Qian Zhengming
Published: March 2010

Engaging the debate regarding the appropriate level of geographic diversification for multinational enterprises (MNEs), we examine a critical, yet unresolved, question: How is performance impacted by the MNE's level of intra‐ and inter‐regional diversification versus the total level of geographic diversification? Using data from 123 U.S.‐based MNEs over a seven‐year period and leveraging both sales‐based and subsidiary‐based measures for diversification, we find that performance increases at an increasingly higher rate as firms concentrate more heavily on intra‐regional diversification. Regarding inter‐regional diversification and total geographic diversification, we find inverted‐U relationships to exist between firm performance and the level of geographic diversification. Different from recent research on multinationality, our robustness checks indicate no evidence of a sigmoidal relationship between the degree of regional diversification and performance. Copyright © 2010 John Wiley & Sons, Ltd.
FDI spillovers in an emerging market: the role of foreign firms' country origin diversity and domestic firms' absorptive capacity
Authors: Zhang Yan , Li Haiyang , Li Yu , Zhou Li‐An
Published: March 2010

Prior literature on foreign direct investment (FDI) spillovers has mainly focused on how the presence of FDI affects the productivity of domestic firms. In this study, we advance the literature by examining the effect of the diversity of FDI country origins on the productivity of domestic firms. We propose that the diversity of FDI country origins can facilitate FDI spillovers by increasing the variety of technologies and management practices brought by foreign firms, to which domestic firms are exposed and that they can potentially utilize. Further, the extent to which domestic firms can utilize these technologies and practices depends upon their absorptive capacity. Using panel data on Chinese manufacturing firms during the period 1998–2003, our results support these propositions. We find that the diversity of FDI country origins in an industry has a positive relationship with the productivity of domestic firms in the industry. This positive relationship is stronger when domestic firms are larger, and when the technology gap between FDI and the domestic firms is intermediate. Copyright © 2010 John Wiley & Sons, Ltd.
One step further towards the dematerialization of building envelopes — the new European Investment Bank building in Luxembourg
Authors: Sobek Werner , Tarazi Frank
Published: March 2010

The new office building for the European Investment Bank in Luxembourg was built to a design by Dusseldorf‐based architect Christoph Ingenhoven. The particular features of this building are its cable façades as well as the curving glass envelope spanning over the whole structure. This article provides a detailed description of the steel‐and‐glass structures to the façades and barrel vault, which are the main elements determining the building’s appearance. Particular attention is paid to the very high safety standards applied to all structures. Thanks to a sophisticated combination of various loadbearing elements it was possible to unite maximum transparency with remarkable robustness.
The “general method” for assessing the out‐of‐plane stability of structural members and frames and the comparison with alternative rules in EN 1993 — Eurocode 3 — Part 1‐1
Authors: Bijlaard Frans , Feldmann Markus , Naumes Johannes , Sedlacek Gerhard
Published: March 2010

The key to harmonizing the rules for the assessment of in‐plane and out‐of‐plane stability of structural steel members is a common definition of equivalent geometric imperfections. The nature of these is given by the elastic‐critical buckling mode and their amplitudes are obtained from the evaluation of test results for member resistance according to EN 1990 — Annex D — Basis of structural design.

EN 1993 — Part 1‐1 — Design of steel structures — contains a set of alternative rules for stability checks. Of these, the “general method” could potentially function as a consistent and reliable set of rules for assessing both flexural and lateral‐torsional buckling for any loading and support conditions, and also cover the case of combined compression, biaxial bending and torsion. This report describes the basis of the “general method” and its extension to the treatment of any stability problems in bar structures.

The reliability of the method is verified by test evaluations. This means it can be used as reference method for checking the accuracy of the other alternative stability rules in EN 1993‐1‐1. A comparison shows that the other alternative rules meet the requirements on the whole, with deviations of about ±10 %, which define their modelling uncertainty.
Non‐linear seismic dynamic response of curved steel bridges equipped with LRB supports
Authors: Galindo Carlos Mendez , Belda Javier Gil , Hayashikawa Toshiro
Published: March 2010

The susceptibility of horizontally curved steel highway bridges to seismic damage increases substantially when subjected to Level II Earthquake Ground Motions. The growing need for safer bridges has stimulated the replacement of vulnerable steel bearing supports with seismic isolation devices. The purpose of the present study is to analyse the overall performance of highway bridges, with an emphasis on the effectiveness of seismic isolation based on Lead Rubber Bearings (LRB). The analysis of the bridges was performed on three‐dimensional models using a numerical method based on the dynamic response analysis, considering both geometric and material non‐linearities. The non‐linear bridge models were subjected to strong ground motion records from the 1995 Kobe earthquake. The efficiency of using LRB supports on curved highway viaducts is demonstrated in this study. The results show that seismic isolation improves the seismic response of curved bridges and reduces excessive seismic damage.
Stresses in the zone of process openings in the shell of a vertical cylindrical steel tank
Authors: Ziólko Jerzy , Supernak Ewa , Mikulski Tomasz
Published: March 2010

Diverse process openings have to be provided in the bottom parts of cylindrical tanks for the storage of liquids. Pipelines have to be connected to each tank product. These are mostly 700 mm in diameter in the case of tanks with a capacity of 50 000 m3 and more. An opening in the tank shell for a pipeline of such a diameter weakens the shell significantly. Furthermore, this occurs in the region where the material is exposed to the greatest stresses — in the zone of boundary disturbances at the junction between the cylindrical shell and the bottom plate.

In the shells of tanks for the storage of crude oil, a large opening in the form of a rectangle, joined at the top to a half‐ellipse, have to be formed in the same zone of boundary disturbances, directly at the shell/bottom junction. Very often such openings are more than 900 mm high, and they can be up to 1500 mm wide (depending on tank capacity). The opening is required for a so‐called cleanout door, designed for the removal of deposits precipitating from crude oil and lying on the tank bottom. To be effective during the cleaning of a tank, such clean‐out doors should have their lower edge flush with the tank bottom. That causes a large change of stresses in the zone of boundary disturbances both in the shell and in the tank bottom. For that reason, both of these structural components have to be significantly strengthened in the proximity of the clean‐out door.

This paper is concerned with the analysis of stresses in the region of strengthening at both the aforementioned openings in the tank shell. Since the nature of stress changes — and therefore also the strengthening around these openings — is different, this paper has been divided into two parts, each of them having a separate introduction and presenting separate conclusions. Those conclusions are fit for practical applications.
Endoplasmic reticulum stress responses differ in meninges and associated vasculature, striatum, and parietal cortex after a neurotoxic amphetamine exposure
Authors: Thomas Monzy , George Nysia I. , Saini Upasana T. , Patterson Tucker A. , Hanig Joseph P. , Bowyer John F.
Published: March 2010

Amphetamine (AMPH) is used to treat attention deficit and hyperactivity disorders, but it can produce neurotoxicity and adverse vascular effects at high doses. The endoplasmic reticulum (ER) stress response (ERSR) entails the unfolded protein response, which helps to avoid or minimize ER dysfunction. ERSR is often associated with toxicities resulting from the accumulation of unfolded or misfolded proteins and has been associated with methamphetamine toxicity in the striatum. The present study evaluates the effect of AMPH on several ERSR elements in meninges and associated vasculature (MAV), parietal cortex, and striatum. Adult, male Sprague–Dawley rats were exposed to saline, environmentally induced hyperthermia (EIH) or four consecutive doses of AMPH that produce hyperthermia. Expression changes (mRNA and protein levels) of key ERSR‐related genes in MAV, striatum, and parietal cortex at 3 h or 1 day postdosing were monitored. AMPH increased the expression of some ERSR‐related genes in all tissues. Atf4 (activating transcription factor 4, an indicator of Perk pathway activation), Hspa5/Grp78 (Glucose regulated protein 78, master regulator of ERSR), Pdia4 (protein disulfide isomerase, protein‐folding enzyme), and Nfkb1 (nuclear factor of kappa b, ERSR sensor) mRNA increased significantly in MAV and parietal cortex 3 h after AMPH. In striatum, Atf4 and Hspa5/Grp78 mRNA significantly increased 3 h after AMPH, but Pdia4 and Nfkb11 did not. Thus, AMPH caused a robust activation of the Perk pathway in all tissues, but significant Ire1 pathway activation occurred only after AMPH treatment in the parietal cortex and striatum. Ddit3/Chop, a downstream effector of the ERSR pathway related to the neurotoxicity, was only increased in striatum and parietal cortex. Conversely, Pdia4, an enzyme protective in the ERSR, was only increased in MAV. The overall ERSR manifestation varied significantly between MAV, striatum, and parietal cortex after a neurotoxic exposure to AMPH. Synapse 2010. Published 2010 Wiley‐Liss, Inc.
Cocaine enhancement of long‐term potentiation in the CA1 region of rat hippocampus: Lamina‐specific mechanisms of action
Authors: Stramiello Michael , Wagner John J.
Published: March 2010

There is an expanding body of work characterizing dopaminergic modulation of synaptic plasticity in the hippocampus CA1 region, an area known to be involved in learning and memory. However, in vitro studies to date have focused almost exclusively on the proximal and distal apical dendritic layers (strata radiatum and lacunosum moleculare, respectively). In this report, we establish that dopaminergic activity can enhance long‐term potentiation (LTP) in the basal dendritic layer (stratum oriens) of CA1 in the rat hippocampal slice preparation. Application of the D1/5 agonist SKF38393 (20 μM) significantly increased the magnitude of basal LTP of the fEPSP response following high‐frequency stimulation of the Schaffer collateral/commissural inputs in the stratum oriens layer. In addition, endogenous dopamine (DA) activity facilitated by the presence of cocaine (6 μM) was also capable of enhancing the magnitude of basal LTP. Prior application of the D1/5 antagonist SKF83566 (2 μM) prevented this effect of cocaine, indicating that endogenously released dopamine was exerting its LTP‐enhancing effect in stratum oriens via activation of D1/5 receptors. This final result stands in contrast with the previously characterized effects of cocaine on apical LTP in the stratum radiatum, which instead have been shown to require D3 receptor activation. These observations demonstrate that dopaminergic mechanisms resulting in the enhancement of hippocampal LTP are lamina specific at Schaffer collateral/commissural synapses in the CA1 region. Synapse 2010. © 2010 Wiley‐Liss, Inc.
Changes in dendritic morphology and spine density in motor cortex of the adult rat after stroke during infancy
Authors: Hartle Kelly D. , Jeffers Matthew S. , Ivanco Tammy L.
Published: March 2010

Cognitive and motor deficits are pervasive in children that suffer early brain injury. The aim of this study was to determine the impact that early damage has on dendritic spine density and other aspects of dendritic morphology of neurons in the motor cortex. Also of interest was how changes in dendritic structure evolved across the lifespan. Ischemia was induced in 10‐day‐old Long Evans rats by injection of Rose Bengal dye and a laser positioned over right motor cortex. Animals were sacrificed at two and six months of age, and brains were processed for Golgi‐Cox staining. Animals exposed to early damage exhibited increases in length of basilar dendrites at two months of age, however no differences in spine density were found across groups at this age. At six months of age, injured animals demonstrated an overall decrease in apical and basilar spine density. Our results suggest that the changes in dendritic length and spine density observed after early damage are unable to be maintained as the animal ages. The observation that increases in spine density do not necessarily coincide with increases in dendritic length suggests that the two processes may not be dependent on one another and suggest two independent plasticity processes responding to damage. Synapse 2010. © 2010 Wiley‐Liss, Inc.
Decreased Beta2*‐nicotinic acetylcholine receptor availability after chronic ethanol exposure in nonhuman primates
Authors: Cosgrove Kelly P. , Kloczynski Tracy , Bois Frederic , Pittman Brian , Tamagnan Gilles , Seibyl John P. , Krystal John H. , Staley Julie K.
Published: March 2010

Ethanol associated behaviors have been linked to the β2‐subunit containing nicotinic acetylcholine receptors (β2*‐nAChR); however, there is conflicting evidence on ethanol‐induced changes in nAChR expression during and after chronic ethanol consumption. In this study, five male animals orally self‐administered ethanol for 18 ± 1 weeks. Animals were scanned with [123I]5‐IA‐85380 and SPECT prior to ethanol self‐administration, and at 24 h and 5‐13 wks withdrawal. β2*‐nAChR availability was not significantly different from baseline at 24 h withdrawal, but was significantly decreased compared to baseline at 5‐13 wks withdrawal throughout the cortex and in the thalamus, but not the midbrain. The percent decrease in β2*‐nAChR availability from baseline to 5‐13 wks withdrawal in the parietal cortex was negatively correlated with total grams of ethanol consumed in lifetime and in the midbrain was negatively correlated with average daily ethanol consumption (g/kg). Prolonged withdrawal from chronic ethanol consumption is associated with a decrease in β2*‐nAChR availability. The decrease in β2*‐nAChR availability is influenced by alcohol consumption, suggesting the chronicity and severity of alcohol consumption may underlie persistent changes in β2*‐nAChR availability. Synapse 64:729–732, 2010. © 2010 Wiley‐Liss, Inc.
Integrated general education: A brief look back
Authors: Wehlburg Catherine M.
Published: March 2010

By tracing the historical roots of general education, we can make many of our current issues and problems in general education more understandable. This chapter is an overview of historical trends that have taken general education from the concept of a unified curriculum with no distinction between “specialized” and “general” education to the current distribution requirement that many institutions use.
Making general education matter: Structures and strategies
Authors: Hawthorne Joan , Kelsch Anne , Steen Tom
Published: March 2010

When the University of North Dakota began working to improve general education, two concerns were recognized. The first issue, which faculty and administrators across campus found immediately engaging, was how to change general education so that it would be a better program, more likely to yield clear student learning benefits. A second concern, less obvious but ultimately more significant, was how to make general education really matter. This cross‐campus faculty engagement in general education goals has been extremely energizing, essentially making the program matter to faculty across disciplines; and this heightened faculty interest is already translating to students as faculty engage more purposefully with the program.
Unifying the undergraduate curriculum through inquiry‐guided learning
Authors: Lee Virginia S. , Ash Sarah
Published: March 2010

At North Carolina State University, inquiry‐guided learning offered a compelling framework for integrating the undergraduate curriculum across general education and the major. Rather than adopting a definition of inquiry‐guided learning as a prescribed set of approaches, participating faculty and staff members agreed on four overarching intended learning outcomes as the distinctive feature of inquiry‐guided learning: critical thinking, habits of independent inquiry, taking responsibility for one's own learning, and intellectual growth and maturity. Regardless of discipline, faculty members were able to translate the outcomes readily into terms that had meaning within their disciplinary context. As a result the outcomes offered a common language that provided unity to the undergraduate experience for faculty members and ultimately for students.
University of the Pacific's bookend seminars on a good society
Authors: Matz Lou
Published: March 2010

University of the Pacific is a private, comprehensive university with a College of Arts and Sciences and six professional schools, and with a population of more than four thousand students on its main campus in the ethnically diverse central valley city of Stockton, California. The signature component of Pacific's general education program is the required three Pacific Seminars (PACS) that focus on the question “What is a Good Society?” PACS 1 and 2 are writing‐intensive, discussion‐oriented seminars taken in sequence in the first year, and each course consists of some forty sections of about twenty students per section. PACS 3 is a culminating educational experience taken in the senior year and consists of thirty‐one sections of twenty‐five students per section spread throughout the entire year.
Creating an integrative general education: The Bates experience
Authors: Reich Jill , Head Judy
Published: March 2010

A college education has never been so necessary, or so expensive. It is incumbent upon us, the educators, to do it the best we can. The products of our work are not the buildings on our campuses but our students who go out into this complicated and exciting world to serve as its leaders, its citizens, and its workers. The Bates College general education curriculum is used in this chapter to articulate the importance of several integrative goals and processes that make up our new general education curriculum.
Synthesis and Characterization of trans‐PdII Trimethylsilylchalcogenolates
Authors: Niebel Tobias , MacDonald Daniel G. , Khadka Chhatra B. , Corrigan John F.
Published: March 2010

The trans‐bis(trimethylsilyl)chalcogenolate palladium complexes, trans‐[Pd(ESiMe3)2(PnBu3)2] [E = S (1) and Se (2)] were synthesized in good yields and high purity by reacting trans‐[PdCl2(PBu3)2] with LiESiMe3 (E = S, Se), respectively. These complexes were characterized by 1H, 13C{1H}, 31P{1H} (and 77Se{1H}) NMR spectroscopy and single‐crystal X‐ray analysis. The reaction of 2 with propionyl chloride led to the formation of trans‐[Pd(SeC(O)CH2CH3)2(PnBu3)2] (3), a trans‐bis(selenocarboxylato) palladium complex and thus established a new method for the formation of this type of complex. Complex 3 was characterized by 1H, 13C{1H}, 31P{1H} and 77Se{1H} NMR spectroscopy and a single‐crystal X‐ray structure analysis.
Ternary Silicides Sc3TSi3 (T = Ru, Rh, Ir, Pt) – Structure, Chemical Bonding, and Solid State NMR
Authors: Harmening Thomas , Mohr Daniel , Eckert Hellmut , Al Alam Adel , Matar Samir F. , Pöttgen Rainer
Published: March 2010

New complex silicides Sc3TSi3 (T = Ru, Rh, Ir, Pt) were prepared by arc‐melting of the elements. They crystallize with a new orthorhombic structure type, space group Pnma. The four structures were refined from single crystal diffractometer data: a = 1167.6(3), b = 398.20(9), c = 1026.9(2) pm, wR2 = 0.0559, 923 F2 values for Sc3RuSi3, a = 1166.8(1), b = 401.85(5), c = 1019.7(1) pm, wR2 = 0.0355, 819 F2 values for Sc3RhSi3, a = 1160.7(2), b = 402.84(6), c = 1015.1(2) pm, wR2 = 0.0352, 905 F2 values for Sc3IrSi3, and a = 1166.3(1), b = 403.18(5), c = 1019.3(2) pm, wR2 = 0.0465, 917 F2 values for Sc3PtSi3 with 44 variables per refinement. The Sc3TSi3 structures contain complex three‐dimensional [TSi3] polyanionic networks with slightly distorted tetrahedral silicon coordination of the transition metal atoms, e.g. 237–254 pm Ru–Si in Sc3RuSi3. The RuSi4 tetrahedra share common corners along the short unit cell axis and these rows are connected by Si–Si bonds, leading to Si3 units (243–244 pm Si–Si) within the [RuSi3] polyanion. Ab initio electronic structure investigations point to dominating Ru–Si interactions and show strong electron localization around the Si3 units, underlining the polyanionic character. Significant differences in the 45Sc quadrupolar interaction strengths between the three distinct scandium sites in the Sc3TSi3 silicide were detected by lineshape analyses of field dependent 45Sc MAS as well as 2D TQMAS NMR spectroscopic data. By comparing the experimentally obtained quadrupole interaction parameters with theoretically calculated ones a site assignment of the equal intense signals is possible.
Magnetic and Structural Properties of Heusler Compounds with 27.8 Valence Electrons
Authors: Graf Tanja , Barth Joachim , Jung Verena , Gloskovskii Andrei , Balke Benjamin , Felser Claudia
Published: March 2010

Co2‐based Heusler compounds with 27.8 valence electrons exhibit an exceptional electronic structure that makes them interesting materials for the application in spintronics. Co2Cr0.6Fe0.4Al is the most prominent example of this particular family of compounds. In this article new materials of this class are tested with respect to their structural and magnetic properties. X‐ray diffraction, Mössbauer spectroscopy, energy dispersive X‐ray spectroscopy, and SQUID magnetometry were carried out to characterize the compounds. The use of Co2Fe0.45Ti0.55Ge as a new material in spintronic devices is suggested.
Untersuchungen zu Reaktionen des Diphosphanylsilans iPr2Si(PH2)2 mit Erdalkalimetallsilazaniden
Authors: von Hänisch Carsten , Kopecky Peter
Published: March 2010

The reaction of iPr2Si(PH2)2 (1) with [Ca{N(SiMe3)2}2(THF)2] at 25 °C in molar ratio 1:1 yields the compound [Ca3{iPr2Si(PH)2}3(THF)6] (2). Compound 2 consists of two Ca2P3 trigonal bipyramids with one conjoint calcium corner and SiiPr2 bridged phosphorus atoms. In contrast, the same reaction at 60 °C yield the complex [Ca({P(SiiPr2)2PH}2(THF)4] (3). The isotype strontium compound [Sr({P(SiiPr2)2PH}2(THF)4] (4) was obtained from the reaction of iPr2Si(PH2)2 with [Sr{N(SiMe3)2}2(DME)2]. The Compounds 2–4 were characterised by single crystal X‐ray diffraction, elemental analysis as well as IR and NMR spectroscopic techniques.
Extraction and Analysis of Tomato Seed Oil
Authors: Eller F. J. , Moser J. K. , Kenar J. A. , Taylor S. L.
Published: March 2010

Tomato seeds represent a very large waste by‐product from the processing of tomatoes into products such as tomato juice, sauce and paste. One potential use for these seeds is as a source of vegetable oil. This research investigated the oil content of tomato seeds using several extraction techniques as well as an examination of the oil extracts to determine the composition of the minor constituents such as phytosterol and antioxidant composition. The oxygen radical absorbance capacity (ORAC) of the tomato seed oils were also measured and correlated with antioxidant contents. This research demonstrated that tomato seed oil yield was highest using hot ethanol and followed by hot hexane and finally SC‐CO2. The SC‐CO2 treatment, however, had the highest total phytosterol content as well as highest individual phytosterol content. Sitosterol, cycloartanol, and stigmasterol were the most abundant phytosterols present in the extracts. The highest concentrations of antioxidants were found in the hexane extract. The most abundant antioxidants found in the tomato seed oils were all‐trans‐lycopene, cis‐3‐lycopene and β‐carotene. ORAC was highest for the hexane extract. Oil yield was inversely proportional to both α‐tocopherol and γ‐tocopherol content and positively correlated with cis‐3‐lycopene content. ORAC values were positively correlated with only all‐trans‐lycopene and cis‐3‐lycopene demonstrating their role as antioxidants in the tomato seed oil.
Supercritical Carbon Dioxide Extraction of Sorghum Bug (Agonoscelis pubescens) Oil Using Response Surface Methodology
Authors: Mariod Abdalbasit Adam , Abdelwahab Siddig Ibrahim , Gedi Mohamed Abdulkadir , Solati Zeinab
Published: March 2010

Supercritical fluid extraction (SFE) of sorghum bug oil (SBO) with carbon dioxide was performed and compared with Soxhlet extraction using hexane. Response surface methodology (RSM) was used to determine the effects of pressure (200–400 bar) and temperature (50–70 °C) on the sorghum bug oil yield in SC‐CO2. The high extraction yield (more than 45.0%) was obtained at 300 bar and 60 °C followed by 400 bar and 70 °C, while the lower yield was obtained at 159 bar and 60 °C. At low pressure levels (159 and 200 bar), the oil yield decreased due to the reduced density of CO2 at higher temperatures. Gas chromatography was used to characterize the fatty acids of the oils obtained while α‐tocopherol was quantified by HPLC. No differences were found in the fatty acid compositions of the various extracts, while the α‐tocopherol extracted from sorghum bug oil by the conventional solvent method was less than that extracted by the SFE process using CO2. It can be observed that the conventional solvent extraction method exhibited notable DPPH radical‐scavenging activity, with an efficacy slightly lower (IC50 7.45 ± 0.3) than that of the SFE extracts.
Nanoprobe measurements of materials at megabar pressures
Authors: Wang Lin , Ding Yang , Yang Wenge , Liu Wenjun , Cai Zhonghou , Kung Jennifer , Shu Jinfu , Hemley Russell J. , Mao Wendy L. , Mao Ho-kwang
Published: March 2010

The use of nanoscale x-ray probes overcomes several key limitations in the study of materials up to multimegabar (> 200) pressures, namely, the spatial resolution of measurements of multiple samples, stress gradients, and crystal domains in micron to submicron size samples in diamond-anvil cells. Mixtures of Fe, Pt, and W were studied up to 282 GPa with 250–600 nm size synchrotron x-ray absorption and diffraction probes. The probes readily resolve signals from individual materials, between sample and gasket, and peak pressures, in contrast to the 5-μm-sized x-ray beams that are now becoming routine. The use of nanoscale x-ray beams also enables single-crystal x-ray diffraction studies in nominally polycrystalline samples at ultrahigh pressures, as demonstrated in measurements of (Mg,Fe)SiO
3
postperovskite. These capabilities have potential for driving a push toward higher maximum pressures and further miniaturization of high-pressure devices, in the process advancing studies at extreme conditions.
Nanofluidics in hollow nanowires
Authors: Sköld Niklas , Hällström Waldemar , Persson Henrik , Montelius Lars , Kanje Martin , Samuelson Lars , Prinz Christelle N , Tegenfeldt Jonas O
Published: March 2010

We present a novel scheme for producing nanotube membranes using free-standing hollow nanowires, with easily controllable dimensions. GaAs–AlInP core–shell nanowires were grown by metal–organic vapor phase epitaxy and were partially embedded in a polymer film. The GaAs core and substrate were etched selectively, leaving tubes with open access to both sides of the membrane. Electrophoretic transport of T4-phage DNA through the hollow nanowires was demonstrated using epifluorescence microscopy.
Description of Undibacterium oligocarboniphilum sp. nov., isolated from purified water, and Undibacterium pigrum strain CCUG 49012 as the type strain of Undibacterium parvum sp. nov., and emended descriptions of the genus Undibacterium and the species Undibacterium pigrum
Authors: Eder Wolfgang , Wanner Gerhard , Ludwig Wolfgang , Busse Hans-Jürgen , Ziemke-Kägeler Frank , Lang Elke
Published: March 2010

A Gram-negative, oxidase- and catalase-positive, flagellated, rod-shaped bacterium, designated strain EM 1T, was isolated from purified water. 16S rRNA gene sequence analysis indicated that the novel strain belonged to the family Oxalobacteraceae within the class Betaproteobacteria; the closest phylogenetic relative was Undibacterium pigrum DSM 19792T (96.7 % gene sequence similarity). The new isolate could be distinguished from the type strain of U. pigrum DSM 19792T (=CCUG 49009T=CIP 109318T) and from strain CCUG 49012T, which has been described as a second genomovar of this species, on the basis of genotypic data and several phenotypic properties. An S-layer was present in the cell envelope in U. pigrum DSM 19792T, but was absent in strains EM 1T and CCUG 49012T. Test conditions were established that enabled strain CCUG 49012T to be distinguished from U. pigrum DSM 19792T. As found for U. pigrum, the main fatty acids of strains EM 1T and CCUG 49012T were summed feature 3 (including unsaturated C16 : 1
ω7c), straight-chain C16 : 0 and unsaturated C18 : 1
ω7c (low percentage in strain CCUG 49012T), and C10 : 0 3-OH was the sole hydroxylated fatty acid. The polar lipid profile consisted of the predominant lipids phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The polyamine profile was mainly composed of the major compound putrescine and moderate amounts of 2-hydroxyputrescine. In contrast to U. pigrum and strain CCUG 49012T, where ubiquinone Q8 was reported as the sole quinone component, the quinone system of strain EM 1T consisted of ubiquinone Q-8 (64 %) and Q-7 (36 %). The 16S rRNA gene sequence similarity, the polar lipid profile and the absence of C12-hydroxylated fatty acids all indicated that strain EM 1T was affiliated with the genus Undibacterium. 16S rRNA gene sequence similarity values lower than 97.0 % and several differentiating phenotypic traits demonstrated that strain EM 1T represents a novel species for which the name Undibacterium oligocarboniphilum sp. nov. is proposed (type strain EM 1T=DSM 21777T=CCUG 57265T). In addition, based on previously published results and this study, a separate species, Undibacterium parvum sp. nov., is proposed with strain CCUG 49012T (=DSM 23061T=CIP 109317T) as the type strain.