bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of particle strain in stirred bioreactors by drop breakage investigations
Authors: Maaß Sebastian , Buscher Susanne , Hermann Stephanie , Kraume Matthias
Published: July 2011

Understanding of particle strain and drop breakage is relevant for various technical applications. To analyze it, single drop experiments in a breakage cell and evolving drop size distributions in an agitated system are studied. The mechanisms for particle strain and drop breakage are assumed to be comparable for the investigated turbulent flow regime. The agitation process is simulated using a population balance model. This model provides transient prediction capacities at different scales and can be used for scale‐up/down projects. The number and the size distributions of daughter fragments for single drops have been studied. The results clearly support the assumption of binary breakage. The most common assumption of a Gaussian distribution for the daughter drop size distribution could not be supported. The evolution of a breakage‐dominated toluene/water system was then simulated using different daughter drop size distributions from literature. The computational results were compared with experimental values. All simulations were able to predict the transient Sauter mean diameter excellently but varied strongly in the results on the shape of the distribution. In agreement with the experimental single drop results, the use of a bimodal or a very broad bell‐shaped distribution of the daughter drops is proposed for the simulations. Although these results were obtained in a particular vessel for a specific phase system, it can be applied to simulate transient multiphase systems at different scales. We would expect that the general trends observed in this study are comparable to various applications in multiphase bioreactors.
Development and validation of a method for the determination of buprenorphine and norbuprenorphine in breast milk by gas chromatography–mass spectrometry
Authors: Nikolaou Panagiota , Papoutsis Ioannis , Athanaselis Sotirios , Pistos Constantinos , Dona Artemis , Spiliopoulou Chara
Published: July 2011

Buprenorphine (BUP) is used for the maintenance of opioid‐addicted pregnant women. Because BUP and its main metabolite nor‐BUP are excreted into breast milk, a sensitive and specific GC/MS method has been developed, optimized and validated for their determination in breast milk. BUP‐d4 was used as internal standard. The sample preparation includes combination of protein precipitation with solid‐phase extraction and derivatization (acetylation). The absolute recovery for both analytes was found to be higher than 87.3%. The limits of detection and quantification were 0.07 and 0.20 µg/L, respectively. The calibration curves were linear within the dynamic range 0.20–20.0 µg/L, with a correlation coefficient higher than 0.996. Intra‐ and inter‐day accuracies were ranged from −7.06 to 4.50 and from −5.88 to 7.00%, respectively, while intra‐ and inter‐day precision were less than 5.7 and 6.1%. The analytes were found to be stable in breast milk at 4°C for one week, at −20°C for one month, and after three freeze–thaw cycles. The method can be used for the determination of BUP and nor‐BUP in breast milk of BUP‐maintained mothers, in order to calculate the amount of drug that could pass to the newborn via breast milk and to avoid toxic consequences of breastfeeding. Copyright © 2011 John Wiley & Sons, Ltd.
Ion‐Channel Modulators: More Diversity Than Previously Thought
Authors: Dilly Sébastien , Lamy Cédric , Marrion Neil V. , Liégeois Jean‐François , Seutin Vincent
Published: July 2011

Ion‐channel function can be modified in various ways. For example, numerous studies have shown that currents through voltage‐gated ion channels are affected by pore block or modification of voltage dependence of activation/inactivation. Recent experiments performed on various ion channels show that allosteric modulation is an important mechanism for affecting channel function. For instance, in KCa2 (formerly SK) channels, the prototypic “blocker” apamin prevents conduction by an allosteric mechanism, while TRPV1 channels are prevented from closing by a tarantula toxin, DkTx, through an interaction with residues located away from the selectivity filter. The recent evidence, therefore, suggests that in several ion channels, the region around the outer mouth of the pore is rich in binding sites and could be exploited therapeutically. These discoveries also suggest that the pharmacological vocabulary should be adapted to define these various actions.
Noncovalent Water‐Based Materials: Robust yet Adaptive
Authors: Krieg Elisha , Rybtchinski Boris
Published: July 2011

The adaptive properties of noncovalent materials allow easy processing, facile recycling, self‐healing, and stimuli responsiveness. However, the poor robustness of noncovalent systems has hampered their use in real‐life applications. In this Concept Article we discuss the possibility of creating robust noncovalent arrays by utilizing strong hydrophobic interactions. We describe examples from our work on aqueous assemblies based on aromatic amphiphiles with extended hydrophobic cores. These arrays exhibit fascinating properties, including robustness, multiple stimuli‐responsiveness, and pathway‐dependent self‐assembly. We have shown that this can lead to functional materials (filtration membranes) rivaling covalent systems. We anticipate that water‐based noncovalent materials have the potential to replace or complement conventional polymer materials in various fields, and to promote novel applications that require the combination of robustness and adaptivity.
Novel Silicon‐Containing Analogues of the Retinoid Agonist Bexarotene: Syntheses and Biological Effects on Human Pluripotent Stem Cells
Authors: Bauer Jennifer B. , Lippert W. Peter , Dörrich Steffen , Tebbe David , Burschka Christian , Christie Victoria B. , Tams Daniel M. , Henderson Andrew P. , Murray Bridgid A. , Marder Todd B. , Przyborski Stefan A. , Tacke Reinhold
Published: July 2011

Twofold sila‐substitution (C/Si exchange) of the clinically used RXR‐selective retinoid agonist bexarotene leads to disila‐bexarotene, which displays pharmacological potency similar to that of the parent carbon compound, as shown in a HeLa‐cell‐based RXR assay. Formal exchange of the SiCH2CH2Si group in disila‐bexarotene with a SiCH2Si or SiOSi moiety leads to the disila‐bexarotene analogues 8 and 9. The silicon compounds 8 and 9 were synthesized in multistep syntheses, starting from HCC(CH3)2SiCH2Si(CH3)2CCH and HCC(CH3)2SiOSi(CH3)2CCH, respectively. The key step in the syntheses of 8 and 9 is a cobalt‐catalyzed [2+2+2] cycloaddition reaction that affords the 1,3‐disilaindane and 2‐oxa‐1,3‐disilaindane skeletons. Disila‐bexarotene and its analogues 8 and 9 were studied for their biological effects relative to all‐trans retinoic acid in cultured human pluripotent stem cells. The parent carbon compound bexarotene was included in some of these biological studies. Although the silicon‐containing bexarotene analogues disila‐bexarotene, 8, and 9 appear not to regulate the differentiation of TERA2.cl.SP12 stem cells, preliminary evidence indicates that these compounds may possess enhanced functions over the parent compound bexarotene, such as induction and regulation of cell death and cell numbers. The biological data obtained indicate that bexarotene, contrary to the silicon‐containing analogues disila‐bexarotene, 8, and 9, may partially act to induce cell differentiation.
Stable‐path multi‐channel routing with extended level channel assignment
Authors: Mustafa Saad , Madani Sajjad A. , Bilal Kashif , Hayat Khizar , Khan Samee U.
Published: July 2011

Wireless mesh networks (WMNs) have gained considerable popularity in recent times thanks to their self‐healing, self‐organizing, and self‐configuring nature. Because of their ability to provide high throughput and minimum packet delay, WMNs are considered to be favorable for broadband applications. For such applications, WMNs employ multiple channels, which give rise to issues like channel assignment, load balancing, and interference avoidance. Most of these issues fall into two broad categories, namely routing and channel assignment. For routing, we propose a novel proactive protocol, the stable‐path multi‐channel routing protocol (SMRP). Our proposed solution, to address channel assignment, is the extended level‐based channel assignment (ELCA) scheme. SMRP is designed to work in combination with ELCA in order to minimize interference and balance the load among the underlying nodes. Simulation results show enhanced throughput and minimal packet delay as compared with the contemporary schemes. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of Well‐Dispersed Aqueous‐Phase Magnetite Nanoparticles and Their Metabolism as an MRI Contrast Agent for the Reticuloendothelial System
Authors: Song Yujun , Wang Ruixue , Rong Rong , Ding Jie , Liu Jing , Li Runsheng , Liu Zhenghua , Li Hao , Wang Xiaoying , Zhang Jue , Fang Jing
Published: July 2011

Aqueous‐phase Fe3O4 nanoparticles (NPs), with a size of 9.8 ± 3.0 nm, are directly synthesized by a modified iron salt coprecipitation process, stabilized by the synergistic effect of a combination of poly(vinylpyrrolidone) (PVP), trisodium citrate (TSC), and maleic anhydride (MAH). These NPs show good aqueous‐phase dispersion stability and excellent superparamagnetic properties with a saturation magnetization of 48.0 emu/g at a low magnetic field of 0.5 T. Their biocompatibility and metabolism for application in magnetic resonance reticuloendothelial system examinations are investigated by using rabbits as animal models for the determination of optimized dosage and diagnosis time for the enhanced imaging contrast for the early diagnosis of diseases. Results indicate that a significant darkening effect on the liver epithelial net lymph tissue can be observed in less than 30 min, with about 20 % reduction of the spin–spin relaxation time of T2 after injection. A metabolism study on the NPs indicates that they show little toxicity to the living organs examined, and finally enter into the spleen without obvious retention in any related organs after recycling for more than 2 d.
All else being equal: Are men always higher in social dominance orientation than women?
Authors: Batalha Luisa , Reynolds Katherine J. , Newbigin Carolyn A.
Published: July 2011

The belief in the gender invariance of many traits is a view that dominates much of psychology. In social psychology, this position is clearly represented by social dominance theory and the construct of social dominance orientation (SDO) where it is argued that, all else being equal, men will be higher in SDO than women. In other domains, though, these assumptions are being questioned, and researchers are arguing for a gender similarities hypothesis. The argument is that men and women are more similar than different, and where there are effects for gender, these are small. In this investigation, men and women are compared under similar cultural (Study 1), ideological, (Study 2) and status (Study 3) contexts to examine whether, all else being equal, men really are higher in SDO than women. In an additional study (Study 4), a meta‐analysis is conducted aggregating the effect sizes of the previous studies. Results demonstrated either no effect for gender or an interaction between gender and the relevant social context and only a small effect size of gender—findings that disconfirm the ceteris paribus assumption of social dominance theory. In conclusion, the implications of the findings for understanding gender effects in social psychology are discussed. Copyright © 2011 John Wiley & Sons, Ltd.
A practice‐oriented estimation of the failure probability of building structures
Authors: Fajfar Peter , Dolšek Matjaž
Published: July 2011

In the presented practice‐oriented probabilistic approach for the seismic performance assessment of building structures, the SAC‐FEMA method, which is a part of the broader PEER probabilistic framework and permits probability assessment in closed form, is combined with the pushover‐based N2 method. The most demanding part of the PEER probabilistic framework, that is incremental dynamic analysis, is replaced by the much simpler N2 method, which requires considerably less input data and much less computational time, but which can, nevertheless, often provide: acceptable estimates for the mean values of the structural response. Using some additional simplifying assumptions that are consistent with seismic code procedures, an explicit equation for a quick estimation of the annual probability of “failure” (i.e. the probability of exceeding the near collapse limit state) of a structure can be derived, which is appropriate for practical applications, provided that predetermined default values for the dispersion measures are available. In the paper, this simplified approach is summarized and applied to the estimation of the “failure” probability of reinforced concrete frame buildings representing both old structures, not designed for earthquake resistance, and new structures designed according to Eurocode 8. The results of the analyses indicate a high probability of the “failure” of buildings, which have not been designed for seismic loads. For a building designed according to a modern code, the conservatively determined probability of “failure” is about 30 times less but still significant (about 1% over the lifetime of the structure). Copyright © 2011 John Wiley & Sons, Ltd.
Using a historical aerial photograph analysis to inform trout habitat restoration efforts
Authors: Baillie Marshall B. , Salant Nira L. , Schmidt John C.
Published: July 2011

Restoration of the upper Strawberry River included bank stabilization techniques because it was assumed that excessive bank erosion was degrading spawning habitat for Bonneville cutthroat trout (BCT). Using a long‐term aerial photograph record, the historical range of variability in bank erosion rates and channel geometry was determined, and this information was used to assess present‐day conditions and the rationale for restoration. Relative to historical variability, the channel planform was relatively stable and bank erosion rates were the lowest recorded in the post‐disturbance era. Although a historical loss of riparian vegetation coincided with a shift to a wider and more sinuous channel, lateral migration rates declined and the channel narrowed as riparian cover increased in the decades before restoration, indicating a process of natural recovery. Furthermore, it was found that the percentage of fine sediment in the streambed before restoration was insufficient to affect BCT spawning success. Together these results suggest that bank erosion and fine sediment did not affect the quality of spawning habitat or the abundance of BCT on the upper Strawberry River. The results highlight how a historical analysis can be used to identify the sources of habitat degradation and inform the selection of restoration goals and strategies. Copyright © 2011 John Wiley & Sons, Ltd.
Modelling time varying scouring at bed sills
Authors: Tregnaghi Matteo , Marion Andrea , Bottacin‐Busolin Andrea , Tait Simon J.
Published: July 2011

In this paper a modelling approach is presented to predict local scour under time varying flow conditions. The approach is validated using experimental data of unsteady scour at bed sills. The model is based on a number of hypotheses concerning the characteristics of the flow hydrograph, the temporal evolution of the scour and the geometry of the scour hole. A key assumption is that, at any time, the scour depth evolves at the same rate as in an equivalent steady flow. The assumption is supported by existing evidence of geometrical affinity and similarity of scour holes formed under different steady hydraulic conditions. Experimental data are presented that show the scour hole development downstream of bed sills due to flood hydrographs follow a predictable pattern. Numerical simulations are performed with the same input parameters used in the experimental tests but with no post‐simulation calibration. Comparison between the experimental and model results indicates good correspondence, especially in the rising limb of the flow hydrograph. This suggests that the underlying assumptions used in the modelling approach are appropriate. In principle, the approach is general and can be applied to a wide range of environments (e.g. bed sills, step‐pool systems) in which scouring at rapid bed elevation changes caused by time varying flows occurs, provided appropriate scaling information is available, and the scour response to steady flow conditions can be estimated. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and antibacterial activity of some novel N2‐hydroxymethyl and N2‐aminomethyl derivatives of 4‐aryl‐5‐(3‐chlorophenyl)‐2,4‐dihydro‐3H‐1,2,4‐triazole‐3‐thione
Authors: Plech Tomasz , Wujec Monika , Kaproń Barbara , Kosikowska Urszula , Malm Anna
Published: July 2011

In this investigation, several novel N2‐hydroxymethyl and N2‐aminomethyl derivatives of 5‐(3‐chlorophenyl)‐4‐(4‐methylphenyl)‐2,4‐dihydro‐ 3H‐1,2,4‐triazole‐3‐thione and 4‐(4‐bromophenyl)‐ 5‐(3‐chlorophenyl)‐2,4‐dihydro‐3H‐1,2,4‐triazole‐3‐ thione were prepared. All synthesized compounds were screened for their antibacterial activity against six Gram‐positive and four Gram‐negative bacterial strains. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:737–743, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20737
Synthesis of alkylcarbazole aminoderivatives
Authors: Garman Krzysztof , Olewnik Ewa , Czerwinski Wojciech
Published: July 2011

New alkylcarbazole aminoderivatives were prepared with various alkyl chain lengths. Syntheses were evaluated and procedures simplified. Producing alkylcarbazole aminoderivatives is a two‐step process, where—in the first step—alkycarbazol is obtained in the alkyl chain substitution reaction and the appropriate aminoderivative of alkylcarbazole is synthesized in direct amination of aromatic compounds as the second step. The products were verified with nuclear magnetic resonance analysis, and general thermal properties were determined by thermogravimetric analysis. Alkylcarbazole aminoderivatives are amphiphilic molecules, therefore expanding the list of known surfactants, compatibilizing agents, and other surface modifiers. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:1–4, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/.20742
Novel poly (ADP-ribose) polymerase 1 binding motif in hepatitis B virus core promoter impairs DNA damage repair
Authors: Ko Hui-Ling , Ren Ee-Chee
Published: July 2011

It is well-established that hepatitis B virus (HBV) infection is associated with the development of hepatocellular carcinoma (HCC), but patients with high viral DNA load have significantly higher risk. As host factors are required for efficient viral replication and may, therefore, contribute to high viral DNA load, we screened for host factors that can transcriptionally activate the HBV core promoter (HBVCP). We report here that poly (ADP-ribose) polymerase 1 (PARP1), which is known for its DNA repair activity, binds prominently to an octamer motif in the HBVCP and increases transcriptional efficiency. By utilizing a series of single base substitutions at each nucleotide position of the octamer, the PARP1 binding motif can be defined as “RNNWCAAA.” Intriguingly, introduction of a vector construct bearing tandem repeats of the octamer motif was able to impair the DNA repair function of PARP1. This finding suggests that HBV viral DNA contains specific sequence motifs that may play a role in disrupting the DNA repair pathways of infected hepatocytes.

Conclusion:

This study has identified a novel octamer motif in the HBVCP that binds PARP1, and this interaction increases the replication efficiency of HBV. The presence of this octamer motif in hepatocytes was shown to inhibit the DNA repair capacity of PARP1, potentially contributing to the development of HCC. (Hepatology 2011;)
Reversal of hepatitis B virus-induced immune tolerance by an immunostimulatory 3p-HBx-siRNAs in a retinoic acid inducible gene I–dependent manner
Authors: Han Qiuju , Zhang Cai , Zhang Jian , Tian Zhigang
Published: July 2011

It is extensively accepted that hepatitis B virus (HBV) escapes from innate immunity by inhibiting type I interferon (IFN) production, but efficient intervention to reverse the immune tolerance is still not achieved. Here, we report that 5′-end triphosphate hepatitis B virus X gene (HBx)-RNAs (3p-HBx-short interfering [si]RNAs) exerted significantly stronger inhibitory effects on HBV replication than regular HBx-siRNAs in stably HBV-expressing hepatoplastoma HepG2.2.15 cells through extremely higher expression of type I IFNs, IFN-induced genes and proinflammatory cytokines, and retinoic acid inducible gene I (RIG-I) activation. Also, 3p-HBx-siRNA were more efficient to stimulate type I IFN response than HBx sequence-unrelated 3p-scramble-siRNA in HepG2.2.15 cells, indicating that a stronger immune-stimulating effect may partly result from the reversal of immune tolerance through decreasing HBV load. In RIG-I-overexpressed HepG2.2.15 cells, 3p-HBx-siRNAs exerted stronger inhibitory effects on HBV replication with greater production of type I IFNs; on the contrary, in RIG-I-silenced HepG2.2.15 cells or after blockade of IFN receptor by monoclocnal antibody, inhibitory effect of 3p-HBx-siRNAs on HBV replication was largely attenuated, indicating that immunostimulatory function of 3p-HBx-siRNAs was RIG-I and type I IFN dependent. Moreover, in HBV-carrier mice, 3p-HBx-siRNA more strongly inhibited HBV replication and promoted IFN production than HBx-siRNA in primary HBV+ hepatocytes and, therefore, significantly decreased serum hepatitis B surface antigen and increased serum IFN-β.

Conclusion

: 3p-HBx-siRNAs may not only directly inhibit HBV replication, but also stimulate innate immunity against HBV, which are both beneficial for the inversion of HBV-induced immune tolerance. (Hepatology 2011;)
Vanadium pentoxide induces activation and death of endothelial cells
Authors: Montiel‐Dávalos Angélica , Gonzalez‐Villava Adriana , Rodriguez‐Lara Vianey , Montaño Luis Felipe , Fortoul Teresa I. , López‐Marure Rebeca
Published: July 2011

Vanadium is a transition metal released into the atmosphere, as air‐suspended particles, as a result of the combustion of fossil fuels and some metallurgic industry activities. Air‐suspended particle pollution causes inflammation‐related processes such as thrombosis and other cardiovascular events. Our aim was to evaluate the effect of vanadium pentoxide (V2O5) on endothelial cells since they are key participants in the pathogenesis of several cardiovascular and inflammatory diseases. Cell adhesion, the expression of adhesion molecules and oxidative stress, as well as proliferation, morphology and cell death of human umbilical vein endothelial cells (HUVECs) exposed to V2O5, were evaluated. Vanadium pentoxide at a 3.12 µg cm−2 concentration induced an enhanced adhesion of the U937 macrophage cell line to HUVECs, owing to an increased expression of late adhesion molecules. HUVECs exposed to V2O5 showed an increase in ROS and nitric oxide production, and a diminished proliferation. These changes in vanadium‐treated HUVECs were accompanied by severe morphological changes and apoptotic cell death. Vanadium pentoxide induced serious endothelial cell damage, probably related to the increased cardiovascular morbidity and mortality observed in individuals living in highly air‐polluted areas. Copyright © 2011 John Wiley & Sons, Ltd.
Cloning, expression and functional characterization of carp, Cyprinus carpio, estrogen receptors and their differential activations by estrogens
Authors: Katsu Yoshinao , Lange Anke , Miyagawa Shinichi , Urushitani Hiroshi , Tatarazako Norishisa , Kawashima Yukio , Tyler Charles R. , Iguchi Taisen
Published: July 2011

Sex‐steroid hormones are essential for normal reproductive activity in both sexes. Estrogens are necessary for ovarian differentiation during a critical developmental stage in vertebrates and promote the growth and differentiation of the female reproductive system. Importantly, environmental estrogens can influence the reproductive system and have been shown to disrupt gametogenesis in males. To understand the molecular mechanisms of estrogen actions and to evaluate estrogen receptor ligand interactions in the carp, Cyprinus carpio, a species used widely for both field‐ and laboratory‐based studies, we cloned all three carp estrogen receptors (ER; ERα, ERβ1 and ERβ2) and applied an estrogen‐responsive (ERE)‐luciferase reporter assay system to characterize the interactions of these receptors with steroidal and synthetic estrogens. DNA fragments encoding all three ERs in carp, ERα, ERβ1 and ERβ2, were obtained from the ovary using degenerate primer sets and PCR techniques, and full‐length carp ER (cER) cDNAs were then obtained using RACE (rapid amplification of the cDNA end) techniques. Amino acid sequences of cERs showed overall homology of 46% (α vs β1), 49% (α vs β2) and 53% (β1 vs β2). In the transient transfection ERE‐luciferase reporter assay system (using mammalian cells) the cER proteins displayed estrogen‐dependent activation of transcription and cERβ2 showed a higher sensitivity to the natural steroid oestrogen, 17β‐estradiol, than cERα. The assay system developed is a powerful assay for toxicology and provides a tool for future studies examining the receptor–environmental chemical interactions and estrogen‐disrupting mechanisms in carp. The data presented also expand our knowledge of estrogen receptor evolution. Copyright © 2011 John Wiley & Sons, Ltd.
Radiosynthesis of C‐11 labeled auxin (3‐indolyl[1‐11C]acetic acid) and its derivatives from gramine
Authors: Reid Alicia E. , Kim Sung Won , Seiner Brienne , Fowler Frank W. , Hooker Jacob , Ferrieri Richard , Babst Benjamin , Fowler Joanna S.
Published: July 2011

3‐Indolylacetic acid (IAA) is the major auxin in higher plants and plays a key role in plant growth and development. We report the rapid radiolabeling of the important plant hormone using carbon‐11 (half life: 20.4 min) enabling in vivo imaging of its distribution and movement in whole plants. 3‐Indolyl[1‐11C]acetic acid was synthesized in 2‐steps: (1) reaction of gramine with [11C]cyanide to give 3‐indolyl[1‐11C]acetonitrile in >99% radiochemical purity; (2) hydrolysis of the intermediate in aqueous sodium hydroxide solution to give 3‐indolyl[1‐11C]acetic acid in >98% radiochemical purity after HPLC purification. The overall nondecay corrected radiochemical yield was 28%, synthesis time was 68 min and specific activity was (0.7 mCi/nmol). Hydrolysis proceeded through the formation of 3‐indolyl[1‐11C]acetamide and by varying the temperature of this step, either C‐11 labeled acid or amide were obtained. This procedure provides unexpectedly high C‐11 incorporation in a short time and using a simple and selective hydrolysis without the need of an indole‐nitrogen protecting group or a typical leaving group. Since 3‐indolylacetonitrile and 3‐indolylacetamide are also intermediates in the biosynthesis of IAA, and also function as auxins, this versatile reaction makes all three of these labeled compounds available for imaging studies in whole plants in vivo. Copyright © 2011 John Wiley & Sons, Ltd.
General and specific measures in organizational behavior research: Considerations, examples, and recommendations for researchers
Authors: Judge Timothy A. , Kammeyer‐Mueller John D.
Published: July 2011

Deliberation over and relative preference for general or specific (broad or narrow) constructs has long been an important issue in organizational behavior research. In this article, we provide a review of this general issue and some specific recommendations for researchers. We begin by discussing whether the general versus specific issue is an important debate and by discussing other underlying issues (the role of researcher preferences, distinction between reflective and formative indicators, and distinction between constructs and measures of constructs). Building on Chen's (this issue) analysis of core self‐evaluations, we first discuss how the general–specific debate has progressed in core self‐evaluations research. We then discuss three other important areas in which this debate has played out: intelligence, five‐factor model of personality, and job attitudes. Finally, we offer a framework to help guide decisions about whether to utilize general measures, specific measures, or both and conclude by providing recommendations for the use of general and specific measures in organizational behavior research. Copyright © 2011 John Wiley & Sons, Ltd.
Long‐term‐fertilization effects on soil organic carbon, physical properties, and wheat yield of a loess soil
Authors: Yang Xueyun , Li Pingru , Zhang Shulan , Sun Benhua , Xinping Chen
Published: July 2011

The large dryland area of the Loess Plateau (China) is subject of developing strategies for a sustainable crop production, e.g., by modifications of nutrient management affecting soil quality and crop productivity. A 19 y long‐term experiment was employed to evaluate the effects of fertilization regimes on soil organic C (SOC) dynamics, soil physical properties, and wheat yield. The SOC content in the top 20 cm soil layer remained unchanged over time under the unfertilized plot (CK), whereas it significantly increased under both inorganic N, P, and K fertilizers (NPK) and combined manure (M) with NPK (MNPK) treatments. After 18 y, the SOC in the MNPK and NPK treatments remained significantly higher than in the control in the top 20 cm and top 10 cm soil layers, respectively. The MNPK‐treated soil retained significant more water than CK at tension ranges from 0 to 0.25 kPa and from 8 to 33 kPa for the 0–5 cm layer. The MNPK‐treated soil also retained markedly more water than the NPK‐treated and CK soils at tensions from 0 to 0.75 kPa and more water than CK from 100 to 300 kPa for the 10–15 cm layer. There were no significant differences of saturated hydraulic conductivity between three treatments both at 0–5 and 10–15 cm depths. In contrast, the unsaturated hydraulic conductivity in the MNPK plot was lower than in the CK plot at depths of 0–5 cm and 10–15 cm. On average, wheat yields were similar under MNPK and NPK treatments and significantly higher than under the CK treatment. Thus, considering soil‐quality conservation and sustainable crop productivity, reasonably combined application of NPK and organic manure is a better nutrient‐management option in this rainfed wheat–fallow cropping system.
Laser‐Raman and atomic force microscopy assessment of the chlorococcalean affinity of problematic microfossils
Authors: Kremer Barbara , Bauer Michael , Stark Robert W. , Gast Norbert , Altermann Wladyslaw , Gursky Hans‐Jürgen , Heckl Wolfgang M. , Kazmierczak Józef
Published: July 2011

Organic‐walled microfossils of uncertain origin, classified to an informal group named acritarchs, are most commonly interpreted as the resting cysts of marine eukaryotic phytoplankton. Some acritarchs have recently been interpreted as vegetative cells of chlorococcalean green algae, based on internal bodies that have been interpreted as their asexual reproductive structures (spores). To verify this interpretation, we applied confocal Raman spectroscopy and atomic force microscopy (AFM) to study the ultrastructure and nanostructure of exceptionally preserved acritarchs with internal bodies from the early Silurian cherts (ca 430 Ma‐old) of Frankenwald (Germany). Three‐dimensional Raman mapping showed the spatial distribution of carbonaceous material and other minerals in the walls of the analysed internal bodies and confirmed that these structures are comparable with spores of chlorococcalean microalgae. Our findings document therefore the oldest thus far known vegetative cells of sporulating green algae. The combination of confocal Raman and AFM techniques yielded detailed information about the nanostructure and fossilisation mode of the mineralised organic walls of both the central vesicles and the enclosed spore‐like bodies. Copyright © 2011 John Wiley & Sons, Ltd.
Metal‐nanoparticle‐coating‐induced enhancement and weakening of resonant Raman scattering in ZnO: effect of surface electric field
Authors: Liu H. F. , Huang A. , Tripathy S. , Chua S. J.
Published: July 2011

Effects of Ag and Ti nanoparticle coatings on resonant Raman scattering in various ZnO thin films are presented. The longitudinal optical (LO) phonons, irrespective of the ZnO quality, exhibit an enhancement and a weakening by the Ag and Ti nanoparticle coatings, respectively. The enhancement (weakening) is always accompanied by a reduced (an increased) intensity ratio of the second to first‐order LO phonons, which can be associated with changes in the electron‐phonon coupling strength in the probed area of ZnO. Angle‐resolved X‐ray photoelectron spectroscopy provides evidence for the bending of the surface energy bands and their changes induced by the metal coatings. The effect of metal nanoparticle coatings on the Raman scattering of ZnO is thus attributed to the changes in the surface electric field. Copyright © 2011 John Wiley & Sons, Ltd.
Conformational polymorphism of the antidiabetic drug chlorpropamide
Authors: Ayala A. P. , Caetano M. W. C. , Honorato S. B. , Mendes Filho J. , Siesler H. W. , Faudone S. N. , Cuffini S. L. , Martins F. T. , da Silva C. C. P. , Ellena J.
Published: July 2011

In this paper, the main features of Raman spectroscopy, one of the first choice methods in the study of polymorphism in pharmaceuticals, are presented taking chlorpropamide as a case of study. The antidiabetic drug chlorpropamide (1‐[4‐chlorobenzenesulphonyl]‐3‐propyl urea), which belongs to the sulfonylurea class, is known to exhibit, at least, six polymorphic phases. These forms are characterized not only by variations in their molecular packing but also in their molecular conformation. In this study, the polymorphism of chlorpropamide is discussed on the basis of Raman scattering measurements and quantum mechanical calculations. The main spectroscopic features that fingerprint the crystalline forms are correlated with the corresponding crystalline structures. Using a theoretical approach on the energy dependence of the conformers, simulated molecular torsion angles are plotted versus the formation energy, which provides a satisfactory agreement between the torsion angles at the energy minima and the experimental values observed in the different solid forms of chlorpropamide. Copyright © 2011 John Wiley & Sons, Ltd.
The use of chromium minerals in the 4th–3rd century BC China? A preliminary study of a bronze Pan unearthed from Jiuliandun Graves, Hubei Province, central southern China
Authors: Luo Wugan , Li Tao
Published: July 2011

A bronze Pan (water vessel), dating back to the 4th–3rd century BC, was excavated at Jiuliandun in Hubei Province, central southern China, in 2002. The Pan attracts wide attention among the Chinese archaeologists and conservators for its uniqueness in style and color, which turns out to be due to a black‐brown film of about 1 mm thickness. In the present work, a combined use of X‐ray fluorescence (XRF), micro‐Raman, and X‐ray diffraction (XRD) was employed to determine both chemical and physical compositions of the Pan's film.

The results are summarized as follows: (1) The film, as XRF analysis indicates, has high concentrations of chromium (Cr) and iron (Fe); (2) Both Raman and XRD analyses suggest that the element Cr probably exists in the film mainly in the form of chromium oxide (Cr2O3). Raman analysis also implies the presence of PbCrO4·PbO in the film; (3) XRD analysis suggests that the element Fe exists in the film in the form of magnetite (Fe3O4).

Based on these analytical results and Chinese historical records, we propose that, as early as in the 3rd century BC, people in central southern China might have discovered and intentionally used chromium minerals for bronze surface treatment (such as coating). The source of chromium minerals used in this period was likely Cr‐spinel minerals from meteorites. More work remains to be done to test the possibility of using Cr‐spinel minerals for bronze production and decoration. Other issues, such as the possibility of forming a chromium‐rich film during the underground burial, also need to be solved. Copyright © 2011 John Wiley & Sons, Ltd.
Rocket salad (Diplotaxis and Eruca spp.) sensory analysis and relation with glucosinolate and phenolic content
Authors: Pasini Federica , Verardo Vito , Cerretani Lorenzo , Caboni Maria Fiorenza , D'Antuono Luigi Filippo
Published: July 2011

BACKGROUND: Salad crops of the Brassicaceae family, such as Diplotaxis tenuifolia and Eruca vesicaria, commonly referred to as ‘rocket salads’, have attracted considerable interest as culinary vegetables because of their strong flavour and their content of putative health‐promoting compounds. Among such compounds, glucosinolates and phenolics are well‐known phytochemicals with an important role also in determining the characteristic flavour of these species. In this study, to identify potentially high‐value rocket salads, 37 cultivated types were examined for sensory characters and their relations with glucosinolate and phenolic contents, which ranged from 0.76 to 3.03 g kg−1 dry weight (DW) and from 4.68 to 31.39 g kg−1 DW, respectively.

RESULTS: The perception of bitter taste was significantly affected by specific glucosinolates, namely progoitrin/epiprogoitrin and dimeric glucosativin. Aroma intensity was negatively related to glucoalyssin content, whereas pungency was significantly related to total glucosinolate content. Kaempferol‐3‐(2‐sinapoyl‐glucoside)‐4′‐glucoside was positively and significantly related to all flavour trait perceptions. Aroma intensity, pungency, crunchiness and juiciness were positively related to typical rocket salad flavour perception through a prominent direct effect.

CONCLUSION: Aroma intensity, pungency, crunchiness and juiciness were strong determinants of overall rocket salad flavour perception. Visual traits also characterised sensory components. Bitterness, usually considered a negative flavour trait, was moderately perceived in the examined material, without negatively affecting typical flavour perception. In the range of the examined material, glucosinolate content did not contrast with typical flavour, demonstrating that good taste and putative health‐promoting properties may coexist. Copyright © 2011 Society of Chemical Industry
Counter‐current chromatographic method for preparative scale isolation of picrosides from traditional Chinese medicine Picrorhiza scrophulariiflora
Authors: Chen Zhe , Wu Jianbing , Shen Wei , Liu Pei , Cao Yi , Lu Yanbin
Published: July 2011

Apocynin, androsin, together with picroside I, II and III from crude extracts of Picrorhiza scrophulariiflora were isolated by means of high‐speed counter‐current chromatography (CCC) combining elution‐extrusion (EE) and cycling‐elution (CE) approach. The EECCC took full advantages of the liquid nature of the stationary phase for a complete sample recovery and extended the solute hydrophobicity window, while CECCC showed its unique advantage in achieving effective separation of special compounds through preventing stationary phase loss. In the present work, the biphasic liquid system composed of n‐hexane/ethyl acetate/methanol/water (1:2:1:2, v/v/v/v) was used for separation of apocynin and androsin, ethyl acetate/n‐butanol/water/formic acid (4:1:5:0.005, v/v/v/v) for picroside I, II and III. However, due to the extremely similar K values (K1/K2≈1.2), picroside I and III were always eluted together by several biphasic solvent systems. In this case, the CECCC exhibited great superiority and baseline separated in the sixth cycle using ethyl acetate/water (1:1, v/v) as biphasic liquid system. Each fraction was analyzed by UPLC‐UV and ESI‐MS analysis, and identified by comparing with the data of reference substances. Compared with classical elution, the combination of EE and CE approach exhibits strong separation efficiency and great potential to be a high‐throughput separation technique in the case of complex samples.
Evaluation of matrix effects in analysis of estrogen using liquid chromatography–tandem mass spectrometry
Authors: Nguyen Hien P. , Li Li , Nethrapalli Imam S. , Guo Ningning , Toran‐Allerand C. Dominique , Harrison David E. , Astle C. Michael , Schug Kevin A.
Published: July 2011

Matrix effects of different biological samples, including phosphate‐buffered saline–bovine serum albumin (PBS‐BSA), gelded horse serum, mouse serum, and mouse brain, were investigated for the determination of 17α‐ and β‐estradiol using derivatization with dansyl chloride prior to LC‐MS/MS. Matrix effects were evaluated based on the slopes of regression lines plotted from results obtained in biological matrices versus pure standard solutions. Such plots indicate the enhancement or suppression of signal based on the presence of a particular biological fluid for a particular method. The matrix effects from PBS‐BSA were similar to those of mouse serum. In contrast, analyses performed from horse serum and mouse brain yielded significant ion suppression, especially for 17β‐estradiol. Precipitation during derivatization was observed when pre‐concentrated samples were processed with ethyl acetate as an extraction solvent. This was overcome with the use of methyl tert‐butyl ether; however, matrix effects from this preparation were still present, evidenced by signal suppression and poor linearity in the standard curve. This work affirms that caution should be taken in the transfer of methods for use with different biological matrices, especially in the case where surrogate matrices are necessary for calibration purposes.
Optimization of micro‐HPLC peak focusing for the detection and quantification of low hepcidin concentrations
Authors: Mansion François , Chiap Patrice , Houbart Virginie , Crommen Jacques , Servais Anne‐Catherine , Fillet Marianne
Published: July 2011

Micro‐high‐performance liquid chromatography is a miniaturized, economic and ecological chromatographic system allowing the use of reduced size chromatographic columns. Coupled with electrospray ionization tandem mass spectrometry, this technique can be used to detect and quantify low concentrations of peptides. In this study, hepcidin was used as the model compound and analysed using octadecylsilica stationary phase by means of a gradient elution mode at a flow rate of 4 μL/min. Several parameters were studied to optimize peak focusing. Using the methodology of experimental design, the mobile‐phase gradient conditions and the sample composition were optimized in order to maximize the sensitivity and minimize retention time. Stability of the target peptide in solution was also demonstrated.
Hydrophilic diol monolith for the preparation of immuno‐sorbents at reduced nonspecific interactions
Authors: Gunasena Dilani N. , El Rassi Ziad
Published: July 2011

A polar organic polymer monolith (M1) was introduced for performing immunoaffinity chromatography (IAC) at reduced nonspecific interactions. The M1 monolith was prepared by the in situ polymerization of glyceryl methacrylate (GMM) and pentaerythritol triacrylate (PETA). Through its surface diol groups, M1 provided the functionalities to immobilize antibodies. Anti‐haptoglobin antibody was used as the model antibody to study the overall behavior of the immuno monolith M1 in terms of its binding to the antigen and to evaluate its nonspecific binding with other proteins, especially the high‐abundance human serum proteins. To better assess the suitability of M1 for IAC, other immuno monoliths were prepared and compared with the immuno monolith M1. Two monoliths were of the traditional ones: copolymers of (i) glycidyl methacrylate and ethylene glycol dimethacrylate (EDMA) and (ii) GMM and EDMA, referred to as M2 and M3, respectively. A fourth monolith involving the copolymerization of N‐(3‐aminopropyl)methacrylamide hydrochloride and EDMA (M4) was introduced to allow the site‐directed immobilization of antibodies. Owing to its hydroxyl groups, the M1 exhibited negligible nonspecific hydrophobic interactions with proteins. On the other hand, M4 exhibited extensive electrostatic interactions, while the M2 and to a lesser extent M3 exhibited hydrophobic interactions.
Dextran‐Based Polycations: Thermodynamic Interaction with Water as Compared With Unsubstituted Dextran, 1 – Volumetric Properties and Light Scattering
Authors: Morariu Simona , Eckelt John , Wolf Bernhard A.
Published: July 2011

Dextran and random dextran‐based copolymers containing different molar fractions f of charged units are studied in aqueous solution and in the pure state. The specific volumes of the solutions decrease linearly with increasing weight fraction of the polymer. Extrapolation to the pure state yields information on the hypothetical liquid polymers, exhibiting a pronounced minimum at f ≈ 0.1. A similar dependence is also observed for the pure solid polymers; however, the specific volumes at low f are considerably larger and at high f are slightly smaller. These differences are discussed in terms of the non‐equilibrium structures formed during sample preparation. The thermal expansivities of the solutions pass through a maximum at f ≈ 0.1. Light scattering shows that the thermodynamic quality of water has a minimum at f ≈ 0.1.

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Fluorene‐Containing Poly(ester imide)s and their Application to Positive‐Type Photosensitive Heat‐Resistant Materials
Authors: Hasegawa Masatoshi , Tominaga Azumi
Published: July 2011

Poly(ester imide)s (PEsIs) were prepared from fluorene (FL)‐containing ester‐linked tetracarboxylic dianhydrides and various diamines. The PEsI films achieved excellent combined properties: very high Tg's exceeding 300 °C in some cases, relatively low water absorption, good thermoplasticity, and excellent solubility in common aprotic organic solvents [even when rigid diamines such as p‐phenylenediamine and trans‐1,4‐cyclohexanediamine (CHDA) were used]. In particular, the PEsI film obtained from CHDA also displayed good optical transparency owing to inhibited charge‐transfer interactions. The partial incorporation of the FL‐containing unit into a colorless polyimide system with an extremely low dielectric constant enabled us to form a fine positive‐tone pattern by a photolithograghic technique.

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Magnetoactive Humic‐Based Nanocomposites
Authors: Pomogailo Anatolii D. , Kydralieva Kamila A. , Zaripova Anar A. , Muratov Vladimir S. , Dzhardimalieva Gulzhian I. , Pomogailo Svetlana I. , Golubeva Nina D. , Jorobekova Sharipa J.
Published: July 2011

Summary: We have elaborated several approaches for the preparation of magneto‐active nano‐hybrid composites, including i) ex situ method, which consists of the precipitation of magnetic particles from Fe(II) and Fe(III) salts followed by their incorporation into the humic acids matrix and ii) a chemical precipitation method in situ where the magnetic particles are grown within the humic acids matrix. It was proven that adsorption of humic acids on the magnetic particle surface leads to an enhanced electrostatic and steric stabilization of particles, due to the absorbed layer of highly charged macromolecular compounds. The sorbents under study were found to reveal a high sorption capacity towards uranyl ions. Using the adsorption isotherm, in the linear form of the Langmuir equation, the adsorption parameters were estimated. The results obtained show that the adsorption of uranyl ions by the magneto‐active nanocomposite is enhanced in comparison with the free HA.