bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Dibenzothiophene‐Containing Ladder Polysilsesquioxane as a Blue Phosphorescent Host Material
Authors: Ren Zhongjie , Sun Dianming , Li Huihui , Fu Qiang , Ma Dongge , Zhang Jianming , Yan Shouke 
Published: February 2012

AbstractA ladder polysilsesquioxanes with side chain of dibenzothiophene groups (BS‐LPSQ) was successfully synthesized. The ladder structure of BS‐LPSQ was characterized by MALDI‐TOF MS, XRD, and 1H NMR spectroscopy. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), atomic force microscopy (AFM), and spectroscopic analyses revealed that the BS‐LPSQ has good film‐forming ability, high thermal and morphological stability, and good miscibility to the dopant iridium bis(4,6‐difluorophenyl)pyridinato‐N,C2‐picolinate (FIrpic), high triplet energy, and a wide bandgap. In addition, compared with the ringed polysiloxane BS‐PSQ phosphorescent host material reported previously, the ladder structure of BS‐LPSQ has not only a higher thermal resistance, but also could prevent molecular aggregation and effectively avoid quenching of fluorescence. Thus, the BS‐LPSQ may be used as a better host for the blue‐light‐emitting iridium complex FIrpic. The performance of the electrophosphorescent device, based on the ladder BS‐LPSQ as the active layer, is superior to that of ringed BS‐PSQ and any other polyhedral oligomeric silsesquioxane (POSS)‐based or polymer host materials.
Solution‐phase synthesis and evaluation of tetraproline chiral stationary phases
Authors: Dai Zhi , Ye Guozhong , Pittman Charles U. , Li Tingyu 
Published: February 2012

AbstractA protocol was developed for the solution‐phase synthesis of multigram amounts of two 9‐fluorenylmethoxycarbonyl (Fmoc)‐protected tetraproline peptides. These tetraproline peptides were then attached to amino derivatized silica gel. The replacement of the Fmoc group with the trimethylacetyl group lead to two tetraproline chiral stationary phases (CSPs). A comparison of the chromatographic behavior of these two solution‐phase‐synthesized tetraproline CSPs with that prepared by stepwise solid‐phase synthesis revealed that all three had similar chromatographic performance for resolving 53 model analytes. This suggests that the solution‐phase synthesis of oligoprolines, which allows for the specific benefits of good batch reproducibility, selector homogeneity, and possibly low cost, is a feasible alternative to the solid‐phase synthesis of oligoproline CSPs. Chirality, 2012. © 2012 Wiley Periodicals, Inc.
Force Fields for Studying the Structure and Dynamics of Ionic Liquids: A Critical Review of Recent Developments
Authors: Dommert Florian , Wendler Katharina , Berger Robert , Delle Site Luigi , Holm Christian 
Published: February 2012

AbstractClassical molecular dynamics simulations are a valuable tool to study the mechanisms that dominate the properties of ionic liquids (ILs) on the atomistic and molecular level. However, the basis for any molecular dynamics simulation is an accurate force field describing the effective interactions between all atoms in the IL. Normally this is done by empirical potentials which can be partially derived from quantum mechanical calculations on simple subunits or have been fitted to experimental data. Unfortunately, the number of accurate classical non‐polarizable models for ILs that allow a reasonable description of both dynamical and statical properties is still low. However, the strongly increasing computational power allows one to apply computationally more expensive methods, and even polarizable‐force‐field‐based models on time and length scales long enough to ensure a proper sampling of the phase space. This review attempts to summarize recent achievements and methods in the development of classical force fields for ionic liquids. As this class of salts covers a large number of compounds, we focus our review on imidazolium‐based ionic liquids, but show that the main conclusions are valid for non‐imidazolium salts, too. Insight obtained from recent electronic density functional results into the parametrization of partial charges and on the influence of polarization effects in bulk ILs is highlighted. An overview is given of different available force fields, ranging from the atomistic to the coarse‐grained level, covering implicit as well as explicit modeling of polarization. We show that the recently popular usage of the ion charge as fit parameter can looked upon as treating polarization effects in a mean‐field matter.
Does Corporate Social Responsibility Pay Off in Times of Crisis? An Alternate Perspective on the Relationship between Financial and Corporate Social Performance
Authors: Ducassy Isabelle 
Published: February 2012

ABSTRACTThere are numerous studies analyzing the relationship between corporate social performance (CSP) and financial performance, and even if recent surveys give the upper hand to a generally positive relationship, this question still gives rise to debate. I have chosen to approach this theme from a different angle in order to provide an alternate perspective on this issue: does CSP play a role during periods of uncertainty? I test this hypothesis of CSP acting as an insurance‐like protection on a sample of French listed companies, over several reference periods around the current financial crisis. My findings show a significant positive link between CSP and financial performance for the period corresponding to the beginning of the crisis (second‐half of 2007), but in early 2007 and after the first six months of turmoil, there is no longer a significant connection between the two variables. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.
Use of Industrial Waste for the Manufacturing of Sustainable Building Materials
Authors: Sugrañez Rafael , Cruz‐Yusta Manuel , Mármol Isabel , Martín Francisco , Morales Julián , Sánchez Luis 
Published: February 2012

AbstractPresently, appropriate waste management is one of the main requisites for sustainable development; this task is tackled by the material construction industry. The work described herein is focused on the valorization of granite waste through incorporation, as a filler‐functional admixture, into cement‐based mortar formulations. The main components of the waste are SiO2 (62.1 %), Al2O3 (13.2 %), Fe2O3 (10.1 %), and CaO (4.6 %). The presence of iron oxides is used to develop the photocatalytic properties of the waste. Following heating at 700 °C, α‐Fe2O3 forms in the waste. The inclusion of the heated sample as a filler admixture in a cement‐based mortar is possible. Moreover, this sample exhibits a moderate ability in the photodegradation of organic dye solutions. Also, the plastering mortars, in which the heated samples have been used, show self‐cleaning properties. The preparation of sustainable building materials is demonstrated through the adequate reuse of the granite waste.
Diversity order analysis of orthogonal space–time block coding over keyhole fading channels with antenna selection
Authors: Yang Liang 
Published: February 2012

SUMMARYAlthough there are many research results for the keyhole fading channels in the current literature, fewer results have investigated the antenna selection scheme and quantified the diversity order. In this letter, we first derive some simple statistics of the output signal‐to‐noise ratio for the orthogonal space–time block coding over keyhole fading channels. On the basis of these results, we derive an approximate BER expression for the keyhole MIMO channels with receive antenna selection scheme. Results show that the diversity order with receive antenna selection is min{nR,nT}for nR ≠ nT, which means that the full diversity order with antenna selection is maintained. Finally, numerical results demonstrate the accuracy of our analytical expressions and the tightness of approximate formulas. Copyright © 2012 John Wiley & Sons, Ltd.
Polyphenolic fractions improve the oxidative stability of microencapsulated linseed oil
Authors: Rubilar Mónica , Morales Eduardo , Sáez Roberto , Acevedo Francisca , Palma Barbara , Villarroel Mario , Shene Carolina 
Published: February 2012

AbstractThe main objective of this study was to evaluate the effect of incorporating polyphenolic‐enriched fractions from murta leaves on the oxidative stability of linseed oil microencapsulated by spray drying. For this purpose, polyphenol‐enriched fractions from murta leaves were separated by gel permeation chromatography and chemically characterized. The oxidative stability of microencapsulated linseed oil (MLO) with antioxidants was evaluated in storage conditions at 25°C for 40 days. The antioxidant effects of the polyphenolic fractions and commercial antioxidants (BHT and trolox) on microencapsulated oil were evaluated by the value of conjugated dienes, peroxide, and p‐anisidine. In the initiation step of the oxidation, no significant oxidation delay (p>0.05) in MLO containing fractions F6, F8, or BHT and trolox was observed. However, in the termination step of the oxidation, the addition of fractions F6, F8, and BHT and trolox decreases significantly (p ≤ 0.05) the rancidity in MLO. Furthermore, the results of this study demonstrated the importance of the addition of natural antioxidants such as fractions of murta leaf extract in microencapsulated linseed oil to increase its resistance to oxidation.Practical applications: For incorporating linseed oil, a source of omega‐3 fatty acids, in the diet it is necessary to protect it against oxidative rancidity, the main cause of deterioration that affects food with a high unsaturated fat content. Microencapsulation is effective in retarding or suppressing the oxidation of unsaturated fatty acids and natural plants extracts are effective in inhibiting the lipid oxidation of microencapsulated oil. The use of process technology and a natural additive is expected to increase storage stability and enable its use in dry foods such as instant products. Linseed oil can be used in human nutrition as well as in animal feed as a replacement for fish oil.
Interaction of Ferrocene Mediators with Gluconobacter oxydans Immobilized Whole Cells and Membrane Fractions in Oxidation of Ethanol
Authors: Indzhgiya E. Yu. , Ponamoreva O. N. , Alferov V. A. , Reshetilov A. N. , Gorton L. 
Published: February 2012

AbstractGluconobacter oxydans whole cells and membrane fractions in combination with ferrocene mediators were used to study oxidation of ethanol. The efficiency of mediatorenzyme interaction was assessed by the ratio of maximum current to the apparent Michaelis constant (Imax/KM) for saturating mediator concentrations. The bioelectrocatalytic processes were found to be more efficient with membrane fractions. The highest Imax/KM value of 120 and 3200 µA g/mol for, respectively, cells and fractions was obtained for ferrocene carboxylic acid. In test measurements of biological oxygen demand for rye distillers’ grains, the values obtained by a biosensor based on Gluconobacter membrane fractions and ferrocene were found to correlate with the reference data.
Gold‐Decorated Carbon Composite Electrodes for Enzymatic Oxygen Reduction
Authors: Luckarift Heather R. , Ivnitski Dmitri M. , Lau Carolin , Khripin Constantine , Atanassov Plamen , Johnson Glenn R. 
Published: February 2012

AbstractFunctional composites of carbon and gold nanoparticles create a hierarchical architecture that facilitates high enzyme loading. Subsequent immobilization of the multicopper oxidase, Trametes versciolor laccase, was optimal with dithiobis‐ (succinimidyl propionate), due to the formation of thiol bonds between the protein molecules and gold. The immobilized laccase catalyzed oxygen reduction, with an onset potential of ∼0.6 V (vs. Ag/AgCl), indicated effective orientation of the enzyme redox center to enable direct electron transport between enzyme and the composite electrode. Current densities in half‐cell configurations provide scalable outputs of 50–80 µA/cm2 with the optimized electrode design. The methodology herein describes a rapid, facile preparation of gold‐decorated carbon composite materials for use as electrode scaffolds that can be integrated into a range of bioelectronic devices.
Platinum‐Based and Carbon‐Based Screen Printed Electrodes for the Determination of Benzidine by Differential Pulse Voltammetry
Authors: Falciola Luigi , Pifferi Valentina , Mascheroni Elisabetta 
Published: February 2012

AbstractCarbon‐ and platinum‐based screen‐printed electrodes have been tested, in comparison with standard GC and Pt electrodes, for detecting benzidine, an organic carcinogenic synthetic compound mainly used as intermediate in production of azo‐dyes. The methodology consists in a DPV in acidic media and offers excellent results in terms of large dynamic concentration ranges, high accuracy and precision and low limits of detection (1.2×10−9 M) and quantification (3.7×10−9 M). The use of disposable electrodes eliminates the problems of fouling and surface regeneration of the device. The use of Nafion membrane to further protect Pt‐SPE from fouling is also discussed. The new methodology was also tested on a real water sample.
Differential effects of diazepam, tandospirone, and paroxetine on plasma brain‐derived neurotrophic factor level under mental stress
Authors: Tamaji Ai , Iwamoto Kunihiro , Kawamura Yukiko , Takahashi Masahiro , Ebe Kazutoshi , Kawano Naoko , Kunimoto Shohko , Aleksic Branko , Noda Yukihiro , Ozaki Norio 
Published: February 2012

ObjectivesSerum brain‐derived neurotrophic factor (BDNF) levels are reduced in depressed patients, and successful antidepressant treatment leads to increases in BDNF levels. However, little is known about how psychotropic drugs affect the mechanism of the human response to mental stress. We investigated the influence of psychotropic drugs on plasma BDNF levels under mental stress using a driving simulator (DS) task.MethodsFourteen healthy male volunteers received one of four drugs, diazepam (5 mg), tandospirone (20 mg), paroxetine (10 mg), and matched placebo, in a double‐blind, crossover manner. Subjects were asked to perform the DS task 4 h post‐dosing. Plasma BDNF levels were measured before and after the DS task.ResultsPlasma BDNF levels under the placebo, diazepam, and tandospirone conditions significantly decreased after the DS task compared with before the task. Conversely, no significant differences in plasma BDNF levels were detected under the paroxetine condition.ConclusionAs these three psychotropic drugs have differential effects on plasma BDNF levels under mental stress after 4 h post‐dosing, antidepressants, unlike anxiolytics, might have a prompt positive effect on the mental stress response. Copyright © 2012 John Wiley & Sons, Ltd.
How parents make sense of their young children's expressions of everyday pain: A qualitative analysis
Authors: Liossi C. , Noble G. , Franck L.S. 
Published: February 2012

AbstractBackgroundLittle is known about the communication of everyday pain between young children and their parents, i.e. when children experience pain resulting from minor injury or illness that occur in everyday life. This study aimed to gain an in‐depth understanding of how parents make sense of their young children's expression of everyday pains and how they respond.MethodsParents (n = 48) of children (1–5 years inclusive) participated in focus group discussions at seven children's centres across England where they were asked to describe their children's communication of everyday pain. Thematic analysis was used to analyse the data.ResultsSix main themes were identified in the parents' discourse. Parents described children's pain communication as (1) sharing common elements, but unique to each child; (2) having multifaceted pain and non‐pain‐related purposes; (3) challenging to interpret; (4) influenced by their own pain‐related communication; (5) requiring a variety of pharmacological, psychological and physical strategies to manage. The sixth theme that emerged from the data related to parents' dissatisfaction with health care providers, particularly general practitioners' sometimes quick dismissal of parental concerns about their children's pain and illness complaints.ConclusionsThese findings suggest that parents have well developed, although personal, ways of recognizing and responding to their children's communication of pain, but also experience uncertainty in their judgments. Parents would benefit from information about the developmental aspects of pain and should be included as active partners in their children's pain assessment and management.
Different involvement of autophagy in human malignant glioma cell lines undergoing irradiation and temozolomide combined treatments
Authors: Palumbo Silvia , Pirtoli Luigi , Tini Paolo , Cevenini Gabriele , Calderaro Francesco , Toscano Marzia , Miracco Clelia , Comincini Sergio 
Published: February 2012

AbstractGlioblastoma (GB) has a poor prognosis, despite current multimodality treatment. Beside surgical resection, adjuvant ionizing radiation (IR) combined with Temozolomide (TMZ) drug administration is the standard therapy for GB. This currently combined radio‐chemotherapy treatment resulted in glial tumor cell death induction, whose main molecular death pathways are still not completely deciphered. In this study, the autophagy process was investigated, and in vitro modulated, in two different GB cell lines, T98G and U373MG (known to differ in their radiosensitivity), after IR or combined IR/TMZ treatments. T98G cells showed a high radiosensitivity (especially at low and intermediate doses), associated with autophagy activation, assessed by Beclin‐1 and Atg‐5 expression increase, LC3‐I to LC3‐II conversion and LC3B‐GFP accumulation in autophagosomes of irradiated cells; differently, U373MG cells resulted less radiosensitive. Autophagy inhibition, using siRNA against BECN1 or ATG‐7 genes, totally prevented decrease in viability after both IR and IR/TMZ treatments in the radiosensitive T98G cells, confirming the autophagy involvement in the cytotoxicity of these cells after the current GB treatment, contrary to U373MG cells. However, rapamycin‐mediated autophagy, that further radiosensitized T98G, was able to promote radiosensitivty also in U373MG cells, suggesting a role of autophagy process in enhancing radiosensitivity. Taken together, these results might enforce the concept that autophagy‐associated cell death might constitute a possible adjuvant therapeutic strategy to enhance the conventional GB treatment. J. Cell. Biochem. 113: 2308–2318, 2012. © 2012 Wiley Periodicals, Inc.
Involvement of hnRNP A1 in the matrix metalloprotease‐3‐dependent regulation of Rac1 pre‐mRNA splicing
Authors: Pelisch Federico , Khauv Davitte , Risso Guillermo , Stallings‐Mann Melody , Blaustein Matías , Quadrana Leandro , Radisky Derek C. , Srebrow Anabella 
Published: February 2012

AbstractRac1b is an alternatively spliced isoform of the small GTPase Rac1 that includes the 57‐nucleotide exon 3b. Rac1b was originally identified through its over‐expression in breast and colorectal cancer cells, and has subsequently been implicated as a key player in a number of different oncogenic signaling pathways, including tumorigenic transformation of mammary epithelial cells exposed to matrix metalloproteinase‐3 (MMP‐3). Although many of the cellular consequences of Rac1b activity have been recently described, the molecular mechanism by which MMP‐3 treatment leads to Rac1b induction has not been defined. Here we use proteomic methods to identify heterogeneous nuclear ribonucleoprotein (hnRNP) A1 as a factor involved in Rac1 splicing regulation. We find that hnRNP A1 binds to Rac1 exon 3b in mouse mammary epithelial cells, repressing its inclusion into mature mRNA. We also find that exposure of cells to MMP‐3 leads to release of hnRNP A1 from exon 3b and the consequent generation of Rac1b. Finally, we analyze normal breast tissue and breast cancer biopsies, and identify an inverse correlation between expression of hnRNP A1 and Rac1b, suggesting the existence of this regulatory axis in vivo. These results provide new insights on how extracellular signals regulate alternative splicing, contributing to cellular transformation and development of breast cancer. J. Cell. Biochem. 113: 2319–2329, 2012. © 2012 Wiley Periodicals, Inc.
Conjugated circuits currents in hexabenzocoronene and its derivatives formed by joining proximal carbons
Authors: Randić Milan , Vukičević Damir , Balaban Alexandru T. , Vračko Marjan , Plavšić Dejan 
Published: February 2012

AbstractWe report on calculated CC bond currents for a dozen derivatives of hexabenzocoroenene in which one or more proximal carbon atoms at the molecular periphery have been bridged. The approach that we use is graph‐theoretical in nature, following our outline of this method in 2003, which is based on finding all conjugated circuits in all Kekulé valence structures of these molecules. To the π‐electrons having 4n + 2 π‐electrons are assigned anticlockwise π‐electron currents and to conjugated circuits having 4n π‐electrons are assigned π‐electron currents. One may summarize the results reported in this work by stating that CC bond currents in the compounds considered decrease on going from peripheral rings to the central ring of the molecule, and also that CC bond currents decrease by insertion of bridges to proximal peripheral benzenoid rings. © 2012 Wiley Periodicals, Inc.
Metronidazole photodegradation in aqueous solution by using photosensitizers and hydrogen peroxide
Authors: Sánchez‐Polo Manuel , Rivera‐Utrilla José , Prados‐Joya Gonzalo , Ocampo‐Pérez Raúl 
Published: February 2012

AbstractBACKGROUND: The effectiveness of UV radiation on the indirect photodegradation of metronidazole (MNZ) conducting a kinetic study of the process in the presence of radical promoter (H2O2) and photosensitizer (Sens) promoters (duroquinone, tetrahydroxyquinone, tetrachloro‐1,4‐benzoquinone, 4‐carboxy‐benzophenone, 2,4‐dihydroxybenzophenone, 4‐hydroxybenzophenone, and 4,4′‐dihydroxybenzophenone) was investigated.RESULTS: The electron‐donating groups of photosensitizers may favor MNZ photodegradation through electron transfer. However, the photosensitizers studied showed low effectiveness of MNZ photodegradation in aqueous phase. The presence of H2O2 substantially increased MNZ photodegradation rate, which was enhanced by increasing the concentration of hydrogen peroxide in the system. The contribution of direct photolysis of MNZ in the UV/H2O2 system was drastically decreased with increasing H2O2 concentrations.CONCLUSIONS: The low effectiveness obtained with most of the Sens used demonstrates that metronidazole cannot be photoxidized by indirect photooxidation in aqueous solution. Copyright © 2012 Society of Chemical Industry
Linear models for estimating annual and growing season reference evapotranspiration using averages of weather variables
Authors: Cristea Nicoleta C. , Kampf Stephanie K. , Burges Stephen J. 
Published: February 2012

AbstractWe develop linear regression equations to estimate location‐specific average annual reference evapotranspiration (ETo) using one or more of annual averages of: incoming solar radiation (Rs), air temperature (T), relative humidity (RH), and wind speed (U). We also provide two sets of equations to estimate growing season ETo, either using one or more of annual averages of Rs, T, RH, and U, or using growing season averages of the same variables. The equations are developed using the FAO‐56 Penman–Monteith model ETo estimates as a reference. Supporting weather data to develop the regression equations were from 102 locations (494 station‐years) across the contiguous United States. The models were tested with additional data from 32 stations (114 station‐years). To illustrate potential applications of the regression models, we estimate spatial patterns of annual ETo and growing season ETo across the contiguous United States using existing spatial datasets of annual averages of Rs, T, RH, and U. Other applications of the models provided may include rapid assessments of historical annual and growing season ETo, evaluation of past ETo trends, or evaluation of ETo projected trends based on output from global climate models. Copyright © 2012 Royal Meteorological Society