bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoelectrical Properties and Energetical Structure of Thin Films of Indandione Derivatives
Authors: INDRIKOVA Maira , LATVELS Janis , MUZIKANTE Inta , TUROVSKA Baiba
Published: December 2011

A sandwich type structure of two dimetilaminobenziliden-1,3-indandione (DMABI) derivatives placed between metal electrodes was made to investigate the photoelectrical properties of these derivatives. DMABI is an organic isolator with a wide energy gap and high quantum efficiency of the photogeneration, DMABI derivatives have received also considerable attention because of its large dipole moment and optical nonlinearities. Besides, since it is a photosensitive material, its use in solar systems is very promising. The energy gap of each material and combined system was observed from the spectral dependence of the quantum efficiency of the photoconductivity and results are compared with results of oxidation and reduction potential of the materials. The values showed a good correlation between experimental data of the photoconductivity and voltamperometry and calculated data of the HOMO and LUMO levels of the molecules.http://dx.doi.org/10.5755/j01.ms.17.2.480
Investigation of Density and Velocity of Abrikosov Vortices in YBa2Cu3O7–x Superconducting Thin Films with a Laser-Written Channel for Easy Vortex Motion
Authors: STEPONAVICIENE Lina , SULCAS Jonas , JUKNA Arturas , PLAUSINAITIENE Valentina , ABRUTIS Adulfas , GONG Mufei , SOBOLEWSKI Roman
Published: December 2011

The 0.3-mm-thick, 50-mm-wide and 100-mm-long YBa2Cu3O7-x superconducting bridges with a laser-written, single, Π-shaped channel have been investigated by means of electronic transport measurements at temperatures below the onset of the bridge's superconducting transition temperature. Our results demonstrate that the coherent vortex motion confined in the P-shaped channel can be used for determination of both the density and velocity of Abrikosov magnetic vortices in the channel. The coherent motion of Abrikosov vortices expresses itself as Josephson-like voltage steps, observed on the current-voltage characteristics of our microbridges, measured at zero external magnetic field, in a limited range of temperatures and bias currents. The steps' amplitude corresponds to the entrance of an additional vortex-antivortex pair into the channel's area and change in the vortex velocity. This amplitude also affects the increase of the Lorentz force for energy dissipative drift of the magnetic flux in the channel, but it does not increase, however, with the increase of the biasing current. We present and discuss the results of experimentally measured and calculated energy dissipation, which originated from variations in the vortex density and velocity when the vortices are moving along the channel of the superconducting bridge.http://dx.doi.org/10.5755/j01.ms.17.2.489
Deepwater Horizon Oil Spill: Mental Health Effects on Residents in Heavily Affected Areas
Authors: Osofsky Howard J. , Osofsky Joy D. , Hansel Tonya C.
Published: December 2011

Background:Mental health issues are a significant concern after disasters such as the Deepwater Horizon oil spill in the Gulf of Mexico in 2010. This study was designed to assess the mental health effects on residents of areas of southeastern Louisiana affected by the oil spill.

Methods:Telephone and face-to-face interviews were conducted with residents (N = 452) assessing concerns and direct impact.

Results:The results show that the greatest effect on mental health related to the extent of disruption to participants' lives, work, family, and social engagement, with increased symptoms of anxiety, depression, and posttraumatic stress. Given the location of the oil spill affecting communities that had been devastated by Hurricane Katrina, results also revealed that losses from Hurricane Katrina were highly associated with negative mental health outcomes. Conversely, the ability to rebound after adversity and place satisfaction were highly associated with better mental health outcomes.

Conclusions:Enhanced understanding of mental health effects after the Deepwater Horizon oil spill will help in determining directions for much-needed mental health services after the disaster and in contributing to the knowledge of complex traumatization and the ability to rebound after adversity.

(Disaster Med Public Health Preparedness. 2011;5:280–286)
Genome‐wide SNP genotyping identifies the Stereocilin (STRC) gene as a major contributor to pediatric bilateral sensorineural hearing impairment
Authors: Francey Lauren J. , Conlin Laura K. , Kadesch Hanna E. , Clark Dinah , Berrodin Donna , Sun Yi , Glessner Joe , Hakonarson Hakon , Jalas Chaim , Landau Chaim , Spinner Nancy B. , Kenna Margaret , Sagi Michal , Rehm Heidi L. , Krantz Ian D.
Published: December 2011

Hearing loss is the most prevalent sensory perception deficit in humans, affecting 1/500 newborns, can be syndromic or nonsyndromic and is genetically heterogeneous. Nearly 80% of inherited nonsyndromic bilateral sensorineural hearing loss (NBSNHI) is autosomal recessive. Although many causal genes have been identified, most are minor contributors, except for GJB2, which accounts for nearly 50% of all recessive cases of severe to profound congenital NBSNHI in some populations. More than 60% of children with a NBSNHI do not have an identifiable genetic cause. To identify genetic contributors, we genotyped 659 GJB2 mutation negative pediatric probands with NBSNHI and assayed for copy number variants (CNVs). After identifying 8 mild‐moderate NBSNHI probands with a Chr15q15.3 deletion encompassing the Stereocilin (STRC) gene amongst this cohort, sequencing of STRC was undertaken in these probands as well as 50 probands and 14 siblings with mild‐moderate NBSNHI and 40 probands with moderately severe‐profound NBSNHI who were GJB2 mutation negative. The existence of a STRC pseudogene that is 99.6% homologous to the STRC coding region has made the sequencing interpretation complicated. We identified 7/50 probands in the mild‐moderate cohort to have biallelic alterations in STRC, not including the 8 previously identified deletions. We also identified 2/40 probands to have biallelic alterations in the moderately severe‐profound NBSNHI cohort, notably no large deletions in combination with another variant were found in this cohort. The data suggest that STRC may be a common contributor to NBSNHI among GJB2 mutation negative probands, especially in those with mild to moderate hearing impairment. © 2011 Wiley Periodicals, Inc.
Reinforcement of soy polyol‐based rigid polyurethane foams by cellulose microfibers and nanoclays
Authors: Zhu Min , Bandyopadhyay‐Ghosh Sanchita , Khazabi Mustafa , Cai Hui , Correa Carlos , Sain Mohini
Published: December 2011

Water‐blown rigid polyurethane foams from soy‐based polyol were prepared and their structure–property correlations investigated. Cellulose microfibers and nanoclays were added to the formulations to investigate their effect on morphology, mechanical, and thermal properties of polyurethane foams. Physical properties of foams, including density and compressive strength, were determined. The cellular morphologies of foams were analyzed by SEM and X‐ray micro‐CT and revealed that incorporation of microfibers and nanoclays into foam altered the cellular structure of the foams. Average cell size decreased, cell size distribution narrowed and number fractions of small cells increased with the incorporation of microfibers and nanoclays into the foam, thereby altering the foam mechanical properties. The morphology and properties of nanoclay reinforced polyurethane foams were also found to be dependent on the functional groups of the organic modifiers. Results showed that the compressive strengths of rigid foams were increased by addition of cellulose microfibers or nanoclays into the foams. Thermogravimetric analysis (TGA) was used to characterize the thermal decomposition properties of the foams. The thermal decomposition behavior of all soy‐based polyurethane foams was a three‐step process and while the addition of cellulose microfibers delayed the onset of degradation, incorporation of nanoclays seemed to have no significant influence on the thermal degradation properties of the foams as compared to the foams without reinforcements. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Morphology and mechanical properties of nanocomposites of cellulose acetate and organic montmorillonite prepared with different plasticizers
Authors: de Lima Juliana Aristéia , Augusto Pinotti Caio , Felisberti Maria Isabel , do Carmo Gonçalves Maria
Published: December 2011

Nanocomposites of cellulose acetate and an organically modified montmorillonite (CA/MMTO) were prepared by melt intercalation in a twin‐screw extruder, using two different plasticizers: di‐octyl phthalate (DOP) and triethyl citrate (TEC). The influence of plasticizer type and the organoclay added to the structure, the morphology, and the thermal properties of the nanocomposites was investigated. XRD and SAXS results indicated a significant CA or/and plasticizer intercalation in the clay gallery for the CA/MMTO nanocomposites. In addition, the images obtained by TEM show that the morphology of CA/MMTO nanocomposites is made up of intercalated and exfoliated silicate layers. The glass transition temperature (Tg) of CA with DOP or TEC decreased in at almost same value, which shows the characteristics of both additives as plasticizers for cellulose acetate chains. Tensile tests indicate that the nanocomposites with either of the two plasticizers presented the same performance with respect to material properties. The results demonstrated that, for some applications, TEC is an useful alternative to plasticize CA in order to substitute DOP, a non eco‐friendly plasticizer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
High performance PEEK/AlN micro‐ and nanocomposites for tribological applications
Authors: Goyal R. K. , Tiwari A. N. , Negi Y. S.
Published: December 2011

The tribological properties of poly(ether–ether–ketone) (PEEK)/aluminum nitride (AlN) composites reinforced with micro‐ and nano‐AlN particles were evaluated under dry sliding conditions. The wear resistance of pure PEEK is 10‐fold higher than mild steel. It was further improved by 2‐fold at 20 wt % micro‐AlN and by more than 4‐fold at 30 wt % nano‐AlN composite compared with pure PEEK. The improvement in wear resistance was attributed to a thin and coherent transfer film. However, it was deteriorated on further increasing micro‐AlN. The coefficient of friction of the composites was increased. Scanning electron microscopy and optical microscopy of worn surfaces and transfer films have been explained in detail. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Using an elaboration likelihood approach to better understand the persuasiveness of website privacy assurance cues for online consumers
Authors: Lowry Paul Benjamin , Moody Greg , Vance Anthony , Jensen Matthew , Jenkins Jeff , Wells Taylor
Published: December 2011

Privacy concerns can greatly hinder consumers' intentions to interact with a website. The success of a website therefore depends on its ability to improve consumers' perceptions of privacy assurance. Seals and assurance statements are mechanisms often used to increase this assurance; however, the findings of the extant literature regarding the effectiveness of these tools are mixed. We propose a model based on the elaboration likelihood model (ELM) that explains conditions under which privacy assurance is more or less effective, clarifying the contradictory findings in previous literature. We test our model in a free‐simulation online experiment, and the results of the analysis indicate that the inclusion of assurance statements and the combination, understanding, and assurance of seals influence privacy assurance. Privacy assurance is most effective when seals and statements are accompanied by the peripheral cues of website quality and brand image and when counter‐argumentation—through transaction risk—is minimized. Importantly, we show ELM to be an appropriate theoretical lens to explain the equivocal results in the literature. Finally, we suggest theoretical and practical implications.
Sr–Mg Mixed Oxides as Biodiesel Production Catalysts
Authors: Faungnawakij Kajornsak , Yoosuk Boonyawan , Namuangruk Supawadee , Krasae Pawnprapa , Viriya‐empikul Nawin , Puttasawat Buppa
Published: December 2011

The Sr–Mg basic catalysts were developed for biodiesel production through transesterification of palm oil with methanol. The evidence for synergistic effects between active Sr and Mg species was clearly demonstrated by transesterification tests over a series of Sr–Mg catalysts with varied Sr‐to‐Mg molar ratios. The catalyst properties were characterised by means of temperature‐programmed desorption of CO2 (CO2‐TPD), N2 sorption, XRD, SEM and TEM experiments. The super strong basic site was formed in Sr–Mg catalysts through a partial solid state reaction induced by thermal treatment at 600 °C. The new basic site, together with the original basic site from SrO (average basic site density=757 μmol m−2), effectively catalysed a transesterification reaction at mild conditions. Biodiesel containing 96 % methyl esters was obtained at reaction conditions of 75 min, 60 °C, 0.1 MPa, 3 wt. % catalyst loading and a methanol‐to‐oil ratio of 6:1, and the catalyst exhibited good reusability. Improved surface areas and porosities were also achieved compared to the unsupported SrO. Density functional theory (DFT) calculations of methylpropanoate adsorption on SrO, MgO and Sr/MgO showed that the adsorption energies of all adsorbate–surface complexes corresponded well with the experimental catalytic activity, which increased in the order MgO<SrO<Sr/MgO.
The Inhibition of Liposaccharide Heptosyltransferase WaaC with Multivalent Glycosylated Fullerenes: A New Mode of Glycosyltransferase Inhibition
Authors: Durka Maxime , Buffet Kevin , Iehl Julien , Holler Michel , Nierengarten Jean‐François , Vincent Stéphane P.
Published: December 2011

l,d‐Heptosides (L‐glycero‐D‐manno‐heptopyranoses) are found in important bacterial glycolipids such as lipopolysaccharide (LPS), the biosynthesis of which is targeted for the development of novel antibacterial agents. This work describes the synthesis of a series of fullerene hexa‐adducts bearing 12 copies of peripheral sugars displaying the mannopyranose core structure of bacterial l,d‐heptoside. The multimers were assembled through an efficient copper‐catalyzed alkyne–azide cycloaddition reaction as the final step. The final fullerene sugar balls were assayed as inhibitors of heptosyltransferase WaaC, the glycosyltransferase catalyzing the incorporation of the first L‐heptose into LPS. Interestingly, the inhibition of the final molecules was found in the low micromolar range (IC50=7–45 μM), whereas the corresponding monomeric glycosides displayed high micromolar to low millimolar inhibition levels (IC50 always above 400 μM). When evaluated on a “per‐sugar” basis, these inhibition data showed that, in each case, the average affinity of a single glycoside of the fullerenes towards WaaC was significantly enhanced when displayed as a multimer, thus demonstrating an unexpected multivalent effect. To date, such a multivalent mode of inhibition had never been evidenced with glycosyltransferases.
Guest‐Responsive Covalent Frameworks by the Cross‐Linking of Liquid‐Crystalline Salts: Tuning of Lattice Flexibility by the Design of Polymerizable Units
Authors: Ishida Yasuhiro , Sakata Hiroaki , Achalkumar Ammathnadu S. , Yamada Kuniyo , Matsuoka Yuki , Iwahashi Nobutaka , Amano Sayaka , Saigo Kazuhiko
Published: December 2011

Cross‐linked polymers prepared by the in‐situ polymerization of liquid‐crystalline salts were found to work as solid‐state hosts with a flexible framework. As a component of such hosts, four kinds of polymerizable amphiphilic carboxylic acids bearing alkyl chains with acryloyloxy (A), dienyl (D), and/or nonreactive (N) chain ends (monomeric carboxylic acids; MAAA, MANA, MDDD, and MDND) were used. The carboxylic acids were mixed with an equimolar amount of a template unit, (1R,2S)‐norephedrine (guest amine; GRS), to form the corresponding salts. Every salt exhibited a rectangular columnar LC phase at room temperature, which was successfully polymerized by 60Co γ‐ray‐induced polymerization without serious structural disordering to afford the salt of cross‐linked carboxylic acid (polymeric carboxylic acid; PAAA, PANA, PDDD, and PDND) with GRS. Owing to the noncovalency of the interactions between the polymer framework P and the template GRS, the cross‐linked polymers could reversibly release and capture a meaningful amount of GRS. In response to the desorption and adsorption of GRS, the cross‐linked polymers dramatically switched their nanoscale structural order. A systematic comparison of the polymers revealed that the choice of polymerizable groups has a significant influence on the properties of the resultant polymer frameworks as solid‐state hosts. Among these polymers, PDDD was found to be an excellent solid‐state host, in terms of guest‐releasing/capturing ability, guest‐recognition ability, durability to repetitive usage, and unique structural switching mode.
The Gd3+ complex of 1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetic acid mono(p‐isothiocyanatoanilide) conjugated to inulin: a potential stable macromolecular contrast agent for MRI
Authors: Granato Luigi , Laurent Sophie , Vander Elst Luce , Djanashvili Kristina , Peters Joop A. , Muller Robert N.
Published: December 2011

Reaction of DOTA–NCSA [1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetic acid mono(p‐isothiocyanatoanilide)] with O‐(aminopropyl)inulin (degree of polymerization 25) provided a chelate that formed a kinetically extremely stable Gd3+ complex. No transmetalation was observed with Zn2+. The conjugate has a relaxivity of 21.7 s−1 m m−1 at 20 MHz and 37 °C, and each molecule of the inulin carries on average 35 Gd3+ ions. The parameters governing the relaxivity of this material and of a low‐molecular‐weight model compound prepared by conjugation of DOTA–NCSA and propylamine were evaluated by investigation of their water 1H longitudinal relaxation rate enhancements at different magnetic fields (NMRD) and by studying variable temperature 17O NMR data. The high relaxivity of the inulin conjugate can be ascribed to the efficient slowing down of the molecular tumbling by this carrier. The rotational correlation time at 37 °C of this material is 1460 ps, whereas that of the model compound is 84 ps. Furthermore, both complexes do not interact significantly with human serum albumin, as shown by their NMRD profiles, and do not undergo transmetallation by zinc ions. The inulin conjugate thus has potential for application as a contrast agent for MRI, particularly as a blood pool agent. Copyright © 2011 John Wiley & Sons, Ltd.
Interplay between Defect Structure and Catalytic Activity in the Mo10−xVxOy Mixed‐Oxide System
Authors: Jakes Peter , Blickhan Nina , Jekewitz Tim , Drochner Alfons , Vogel Herbert , Fuess Hartmut , Eichel Rüdiger‐A.
Published: December 2011

The Mo10−xVxOy solid‐solution systems (0≤x≤10) were studied by electron paramagnetic resonance spectroscopy. The results show the existence of paramagnetic vanadyl VO2+ species, whose concentration becomes maximal for Mo5V5Oy. A quantitative analysis of the [VO2+] concentration as a function of the Mo/V ratio allows it to characterize the prevailing defect chemistry in the Mo10−xVxOy system. In this respect, the semi‐conducting properties of Mo10−xVxOy are p‐type in an interval of Mo9V1Oy–Mo5V5Oy and switch into n‐type because of the conduction electrons in a composition range of Mo5V5Oy–Mo1V9Oy. Highest catalytic activity is obtained when vanadium acts as an acceptor center and oxygen vacancies ${\left( {\upsilon _{\rm{O}}^{ \bullet \bullet } } \right)}$ are formed for reasons of charge compensation. In addition to the surface, ${\upsilon _{\rm{O}}^{ \bullet \bullet } }$ and VO2+ centers in the bulk have to be considered too for heterogeneous catalysis.
Oxidative Addition of the CαCβ Bond in β‐O‐4 Linkage of Lignin to Transition Metals Using a Relativistic Pseudopotential‐Based ccCA‐ONIOM Method
Authors: Oyedepo Gbenga A. , Wilson Angela K.
Published: December 2011

A multi‐level multi‐layer QM/QM method, the relativistic pseudopotential correlation‐consistent composite approach within an ONIOM framework (rp‐ccCA‐ONIOM), was applied to study the oxidative addition of the CαCβ bond in an archetypal arylglycerol β‐aryl ether (β‐O‐4 linkage) substructure of lignin to Ni, Cu, Pd and Pt transition metal atoms. The chemically active high‐level layer is treated using the relativistic pseudopotential correlation‐consistent composite approach (rp‐ccCA), an efficient methodology designed to reproduce an accuracy that would be obtained using the more computationally demanding CCSD(T)/aug‐cc‐pCV∞Z‐PP, albeit at a significantly reduced computational cost, while the low‐level layer is computed using B3LYP/cc‐pVTZ. The thermodynamic and kinetic feasibilities of the model reactions are reported in terms of enthalpies of reactions at 298 K (ΔH°298) and activation energies (ΔH‐act). The results obtained from the rp‐ccCA:B3LYP hybrid method are compared to the corresponding values using CCSD(T) and several density functionals including B3LYP, M06, M06 L, B2PLYP, mPWPLYP and B2GP‐PLYP. The energetics of the oxidative addition of CC bond in ethane to Ni, Cu, Pd and Pt atoms are also reported to demonstrate that the rp‐ccCA method effectively reproduces the accuracy of the CCSD(T)/aug‐cc‐pCV∞Z method. Our results show that in the catalytic activation of the CαCβ bond of β‐O‐4, the use of platinum metal catalysts will lead to the most thermodynamically favored reaction with the lowest activation barrier.
ΔNp63 is regulated by BMP4 signaling and is required for early epidermal development in Xenopus
Authors: Tríbulo Celeste , Guadalupe Barrionuevo María , Agüero Tristán H. , Sánchez Sara S. , Calcaterra Nora B. , Aybar Manuel J.
Published: December 2011

Background: It has been established in several models that the p63 gene has an important role in the development of the epidermis and its derivatives. In Xenopus, only the ΔNp63 isoform of this gene has been cloned and its role during epidermal development remains unknown. Results: In this work, we showed that ΔNp63 is expressed in the nonneural ectoderm since the gastrula stage and that it is regulated by the bone morphogenetic protein 4 (BMP4) signaling pathway. Our in vivo and in vitro experiments demonstrated that ΔNp63 is required in the earliest inductive steps of epidermal development. The overexpression of ΔNp63 caused an increase in epidermal markers with a suppression of neural induction while the blocking of ΔNp63 led to the opposite results. Finally, we found that ΔNp63 acts as an anti‐apoptotic gene, regulating the transcription of some apoptotic and anti‐apoptotic factors. Conclusion: The results suggest that ΔNp63 is an essential gene in early epidermal specification under the control of BMP4. Developmental Dynamics 241:257–269, 2012. © 2011 Wiley Periodicals, Inc.
Dynamic expression of Tbx2 subfamily genes in development of the mouse reproductive system
Authors: Douglas Nataki C. , Heng Kathleen , Sauer Mark V. , Papaioannou Virginia E.
Published: December 2011

Background: Tbx2, Tbx3, Tbx4, and Tbx5, members of the Tbx2 subfamily of T‐box transcription factor genes, are important for many aspects of embryonic development and mutations in some human TBX2 subfamily genes cause developmental syndromes. In addition, TBX2 and TBX3 are overexpressed in a variety of cancers, including reproductive system cancers. This study characterizes the expression of Tbx2 subfamily genes during development of the reproductive system. Results: We show that these genes are expressed in both the internal and external reproductive systems. Tbx2 is expressed in gonads and genital ducts, the Wolffian and Müllerian ducts, while Tbx3 is only expressed in genital ducts. Tbx4 is expressed in embryonic and postnatal germ cells. All four genes are expressed in mesenchyme in external genitalia, with Tbx3 and Tbx5 expression in the epithelium as well. Conclusion: This study lays the foundation for investigation of functional requirements for Tbx2 subfamily genes in development of the mammalian reproductive system. Developmental Dynamics 241:365–375, 2012. © 2011 Wiley Periodicals, Inc.
Fibulin‐1 is required during cardiac ventricular morphogenesis for versican cleavage, suppression of ErbB2 and Erk1/2 activation, and to attenuate trabecular cardiomyocyte proliferation
Authors: Cooley Marion A. , Fresco Victor M. , Dorlon Margaret E. , Twal Waleed O. , Lee Nathan V. , Barth Jeremy L. , Kern Christine B. , Iruela‐Arispe M. Luisa , Argraves W. Scott
Published: December 2011

Background: Trabeculation is an integral component of cardiac ventricular morphogenesis and is dependent on the matrix metalloproteinase, ADAMTS1. A substrate of ADAMTS1 is the proteoglycan versican which is expressed in the developing ventricle and which has been implicated in trabeculation. Fibulin‐1 is a versican and ADAMTS1‐binding extracellular matrix protein required for ventricular morphogenesis. Here we investigated the involvement of fibulin‐1 in ADAMTS1‐mediated cleavage of versican in vitro, and the involvement of fibulin‐1 in versican cleavage in ventricular morphogenesis. Results: We show that fibulin‐1 is a cofactor for ADAMTS1‐dependent in vitro cleavage of versican V1, yielding a 70‐kDa amino‐terminal fragment. Furthermore, fibulin‐1‐deficiency in mice was found to cause a significant reduction (>90%) in ventricular levels of the 70‐kDa versican V1 cleavage product and a 2‐fold increase in trabecular cardiomyocyte proliferation. Decreased versican V1 cleavage and augmented trabecular cardiomyocyte proliferation in fibulin‐1 null hearts is accompanied by increased ventricular activation of ErbB2 and Erk1/2. By contrast, versican deficiency was found to lead to decreased cardiomyocyte proliferation and reduced ventricular trabeculation. Conclusion: We conclude that fibulin‐1 regulates versican‐dependent events in ventricular morphogenesis by promoting ADAMTS1 cleavage of versican leading to suppression of trabecular cardiomyocyte proliferation mediated by the ErbB2‐Map kinase pathway. Developmental Dynamics 241:303–314, 2012. © 2011 Wiley Periodicals, Inc.
Effects of climate change on evapotranspiration and soil water availability in Norway spruce forests in southern Finland: an ecosystem model based approach
Authors: Ge Zhen‐Ming , Kellomäki Seppo , Zhou Xiao , Wang Kai‐Yun , Peltola Heli , Väisänen Hannu , Strandman Harri
Published: December 2011

Norway spruce (Picea abies) is sensitive to decreases in soil water availability. In this study, we simulated how the climate change may influence the hydrological processes with impacts on the growth of Norway spruce in three sites located in southern Finland (61oN). The sites differed from each other in regard to the climate and soil water conditions; however, the initial structure of the tree stands was similar. Under the current climate, the canopy surface evaporation (Ec) increased, whereas the transpiration (Et) remained at a constant rate over the simulation period, as the seedlings in the initial stand grew to full maturity. Under the changing climate, on average, the cumulative of Ec and Eg (evaporation from soil surface) were 16% and 14% higher than those under the current climate, respectively, whereas the cumulative Et was 12% lower. The leaf area index (L) increased constantly on the sites with high (SH) and medium (SM) soil moisture, unlike on the site with low (SL) soil moisture. The canopy conductance (gcs) declined rapidly and earlier on the site SL, which implied the acclimation of stomatal behaviour to drought. The increasing water loss through evaporation decreased the water infiltration into the soil profile, resulting in an increasing soil water deficit (Wd), especially on the site SL. It also occurred earlier in all three sites under the changing climate. It was predicted that climate change will create a suboptimal environment for Norway spruce in southern Finland, particularly on the upland sites with lower groundwater table. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of frying on the trans‐fatty acid formation in soybean oils
Authors: Hou Jun‐Cai , Jiang Lian‐Zhou , Zhang Chun‐Wei
Published: December 2011

To evaluate the effects of repeated deep‐frying on the trans‐fatty acid (TFA) formation in soybean oils, simultaneous frying experiments were carried out. French fries were prepared using three different types of soybean oil (pressed soybean oil, PSBO; first‐grade solvent extracted soybean oil, FG‐SESBO; and third‐grade solvent extracted soybean oil, TG‐SESBO). French fries were fried intermittently at 180–185°C for a total frying time of 32 h and at an interval time of 30 min. It was found that the initial amount of total TFAs was 0.29 g/100 g, 0.31 g/100 g, and 0.90 g/100 g in PSBO, TG‐SESBO, and FG‐SESBO, respectively. Before the frying started, the C18:1,t‐9, trans‐linoleic acid (TLA), trans‐linolenic acid (TLNA), and total TFA content of the PSBO and TG‐SESBO were significantly lower than in the FG‐SESBO (p<0.05). However, in the frying oil samples, the final concentration of total TFA in the PSBO, TG‐SESBO, and FG‐SESBO were 1.79 ± 0.17 g/100 g, 1.12 ± 0.10 g/100 g, and 1.70 ± 0.07 g/100 g, which was 6.17‐, 3.61‐, and 1.89‐fold higher that in fresh oil, respectively. The highest increasing slopes of C18:1,t‐9, TLA, TLNA, and total TFA were observed in the PSBO.

Practical applications: A high intake of TFAs has been shown to lead to an increased risk of coronary heart disease. Plant oils, particularly soybean oil, have been widely used in the food industry in China. Frying is one of the most common methods to cook food. The formation of TFAs during frying has been shown to be closely related to the temperature and duration of the frying process. However, the effects of frying on the formation of TFAs in different soybean oils have not been well studied. In the present study, we demonstrated that increasing the number of frying cycles can cause an intensive increase in the concentration of TFAs in different types of soybean oil, but especially in PSBO.
The effects of acyl moiety and temperature on the polymerization of sterols
Authors: Lehtonen Mari , Lampi Anna‐Maija , Agalga Flora , Struijs Karin , Piironen Vieno
Published: December 2011

Unsaturated lipids are prone to oxidize and polymerize when they are exposed to oxygen, heat, and light. Polymerization of the lipids changes the properties of the media, and it is therefore considered a deterioration process. In the present study, the polymerization of steryl esters was investigated. The effects of acyl moiety and temperature were examined by oxidizing neat cholesteryl stearate, oleate, and linoleate and free cholesterol at two temperatures (100 and 140°C). The formed reaction products were characterized by SEC‐RI and silver coordination ion MS (Ag+‐CIS‐MS). Moreover, the secondary oxidation products of sterol were determined by GC‐FID/MS. High‐molecular size compounds could be detected in the steryl esters after the heat treatment, and the presence of oligomers up to pentamers and hexamers could be indicated. In cholesteryl stearate, 79 mg/g of oligomers were measured after 3 days of heating at 100°C, while in cholesteryl oleate and cholesteryl linoleate, the contents were 569 and 809 mg/g, respectively. As the temperature was increased to 140°C, the rate of polymerization increased. After 1 day of heating, 428 mg/g of oligomers were measured in cholesteryl stearate, 552 mg/g in cholesteryl oleate, and 679 mg/g in cholesteryl linoleate. Free cholesterol remained unaltered at 100°C, but at 140°C, 420 mg/g of oligomers were measured after 1 day of heating. In conclusion, polymerization was a considerable reaction as part of the autoxidation of steryl esters. Moreover, the reaction competed with the formation of secondary oxidation products.

Practical applications: Several types of food products are fortified with plant sterols because of their ability to lower serum cholesterol levels. Therefore, it is important to study the oxidation behavior of sterols and their conjugates. The subject is relevant since radicals and oxidation products of sterols may form during the manufacture of the preparations, thus leading to higher contents of oxides and possibly oligomers in the final food products. Polymerization of lipids could affect also the cholesterol‐lowering efficiency of plant sterols in fortified food products. The obtained results improve the knowledge on how the primary and secondary oxidation products react into more stable products that may accumulate during prolonged heating.
Water Management in A PEMFC: Water Transport Mechanism and Material Degradation in Gas Diffusion Layers
Authors: Kandlikar S. G. , Garofalo M. L. , Lu Z.
Published: December 2011

It has now been well recognized that both the performance and durability of proton exchange membrane fuel cells (PEMFCs) are closely related to the water accumulation and transport inside its porous components, particularly in the gas diffusion layer (GDL), and microporous layer (MPL). In this paper, the key GDL and MPL properties that affect water transport through them are first discussed and a review of GDL degradation mechanisms is presented. An intermittent water drainage mechanism across the GDL is discussed. The capillary breakthrough pressure (CBP) and the dynamic capillary pressure (DCP), or recurrent breakthrough dynamics, have been identified as key GDL properties that affect its water management performance and function as indicators of the degradation of GDL material. This work uses a novel ex situ experiment to degrade a GDL by exposing it to an accelerated stress test (AST) that subjects the GDL to elevated operation conditions seen at the cathode side of a PEMFC for an extended period of time. In turn, the effect of the AST on the CBP and DCP is investigated. As a result, a loss of hydrophobicity occurred on the MPL surface. This altered the CBP and DCP, thus decreasing water management in the GDL.
Thermal Effect on Water Transport in Proton Exchange Membrane Fuel Cell
Authors: Thomas A. , Maranzana G. , Didierjean S. , Dillet J. , Lottin O.
Published: December 2011

Adequate water management is critical in proton exchange membrane fuel cells for improving performance and durability. In this paper, we present results of experiments allowing to quantify the effect of a temperature difference between anode and cathode flow field plates on the transport of water. The results confirm the existence of a temperature‐gradient driven flux between the anode and cathode compartments. They show the strong interplay between water management and heat management and they confirm that water flows mostly in vapor form through the porous media of the MEA. Apart from the current density and the difference between the temperature of the electrodes and of the flow field plates, the water flux in the direction perpendicular to the membrane is also (weakly) dependent on the humidification of the gases. No significant effect has been measured as a function of the GDL thickness as well as of the presence or absence of a MPL. However, using a MPL improves significantly the performance of the fuel cell.
Erk1/2 MAPK and mTOR signaling sequentially regulates progression through distinct stages of oligodendrocyte differentiation
Authors: Guardiola‐Diaz Hebe M. , Ishii Akihiro , Bansal Rashmi
Published: December 2011

Myelination is the culmination of a complex process in which oligodendrocyte (OL) progenitors transition through defined stages in a well‐coordinated differentiation program. The signaling mechanisms that regulate this progression are poorly understood. Here we investigate the role of extracellular signal‐regulated‐kinase‐1,‐2 (Erk1/2) and the mammalian target of rapamycin (mTOR), downstream effectors of the Ras/Raf/Mek/Erk and PI3K/Akt/mTOR pathways, at specific stages of OL development in vitro. Using a panel of developmental stage‐specific antigenic markers and pharmacological inhibitors, we provide evidence that Erk1/2 signaling regulates transition of early progenitors to the late progenitor stage and, as a consequence, to the immature OL stage, but not the transition of immature OL to the mature OL stage. In contrast, mTOR signaling is not required for early progenitor transition to late progenitor stage. Surprisingly, it is also not required for the transition of late progenitors to terminally differentiated immature OLs, as has been reported previously, but is required for the next sequential transition of immature OLs to the mature OL stage. Furthermore, mTOR signaling regulates OL cytoskeletal organization and major myelin protein expression. These in vitro findings correlate with our in vivo data showing that inhibition of mTOR by rapamycin injection attenuated the onset of myelination in the early postnatal brain. Thus, these studies demonstrate that Erk1/2 and mTOR signaling sequentially regulates distinct stages of OL progenitor differentiation and suggest that cells in the OL‐lineage require distinct signaling mechanisms to transition through specific stages of their development. © 2011 Wiley Periodicals, Inc.
Glutamate released by Japanese encephalitis virus‐infected microglia involves TNF‐α signaling and contributes to neuronal death
Authors: Chen Chun‐Jung , OU Yen‐Chuan , Chang Cheng‐Yi , Pan Hung‐Chuan , Liao Su‐Lan , Chen Shih‐Yun , Raung Shue‐Ling , Lai Ching‐Yi
Published: December 2011

The substantial activation of microglia in Japanese encephalitis virus (JEV)‐induced Japanese encephalitis found in numerous studies demonstrates that the disease pathogenesis involves bystander damage caused by microglia‐released mediators. Previously, we reported that microglia synthesized and secreted bioactive mediators with neurotoxic potential into the cultured supernatants in response to JEV infection. In this study, we found that the supernatants of JEV‐infected microglia caused MK801‐inhibitable neuronal damage in cultured neurons, indicating a potential excitotoxic mechanism. Infection with JEV was found to elicit the extracellular glutamate accumulation from microglia but not from neuron and astrocyte cultures. The glutaminase inhibitor 6‐diazo‐5‐oxo‐L‐norleucine, cystine/glutamate antiporter inhibitor α‐aminoadipic acid, and the gap junction inhibitor carbenoxolone reduced JEV infection‐induced microglial glutamate release and neurotoxicity. We further demonstrated that tumor necrosis factor‐alpha (TNF‐α) was a key cytokine which stimulated extensive microglial glutamate release by up‐regulating glutaminase expression via signals involving protein kinase C, cAMP responsive element‐binding protein, and CAAT‐enhancer‐binding protein‐beta. Although the elevated expression of excitatory amino acid transporter 1 and 2 was observed in JEV‐infected cells, the glutamate uptake activity was significantly inhibited by TNF‐α. The JEV infection‐induced alterations, such as the extracellular glutamate release and glutamate‐mediated excitoneurotoxicity, also occurred in neuron/glia cultures. Our findings support a potential link between neuroinflammation and the development of excitotoxic neuronal injury in Japanese encephalitis. The link between neuroinflammation and excitotoxic death may involve a mechanism in which TNF‐α released by microglia plays a facilitory role in glutamate excitoneurotoxicity via up‐regulation of glutamate synthesis and down‐regulation of glutamate uptake. © 2011 Wiley Periodicals, Inc.
Impact of multimodal feedback on simulated ergonomic measurements in a virtual environment: A case study with manufacturing workers
Authors: Hu Bo , Zhang Wei , Salvendy Gavriel
Published: December 2011

The purpose of this study was to evaluate the impact of multimodal feedback on ergonomic measurements in a virtual environment (VE) for a typical simulated drilling task. In total, sixty male manufacturing industry workers were divided into five groups. One group performed the working task in a real environment (RE), and ergonomic measurements for this group were used as the baseline for evaluation. The other four groups performed the same task in a virtual environment with different feedback treatments (visual with or without auditory and/or tactile feedback). Five indices – task completion time, maximum force capacity reduction, body part discomfort, rated perceived exertion, and rated task difficulty – were used to evaluate the measurements of each of the four treatments in VE in comparison to the baseline group in RE. The results indicate that the five indices for each of the four treatment groups were significantly higher than those of the RE group. Moreover, the indices of the visual‐only group were significantly higher than those of the other three groups with auditory and/or tactile feedback treatments. The findings of this study can provide a guideline for ergonomic evaluations of work designs in VE and for establishing a virtual reality simulation system. © 2011 Wiley Periodicals, Inc.
Learning From Our Mistakes: What Matters When Incorporating Blogging in the Content Area Literacy Classroom
Authors: Hungerford‐Kresser Holly , Wiggins Joy , Amaro‐Jiménez Carla
Published: December 2011

This manuscript explores the inclusion of blogging as a pedagogical tool with preservice secondary teachers from a variety of content areas. The authors focus on data collected over two and a half years with preservice teachers in the content literacy classroom setting, specifically highlighting the qualitative data collected to determine students’ perceptions of blogging as a pedagogical strategy. Once the study is discussed, and qualitative findings outlined, the authors provide suggestions for other practitioners considering the use of blogging in their classrooms.
Literate Bodies: Multigenerational Participatory Action Research and Embodied Methodologies as Critical Literacy
Authors: Fox Madeline
Published: December 2011

The recent study Polling for Justice (PFJ) used a multigenerational participatory action research approach with embodied methodologies to document youth experiences of education, criminal justice, and public health in New York City. Through an exploration of the PFJ project, this column demonstrates how participatory action research and embodied methodologies can open up new possibilities for developing critical literacies across difference. Youth and adult researchers in PFJ negotiated with each other, with the literature, and with the public to produce new understandings of the language of criminalization and policing through theatre, images, art, and, most fundamentally, through valuing many kinds of expertise. We found that when we included personal experiences as well as survey data, and when we embodied data, through sculptures, images or scenes, we made room for multiple interpretations of language and data to come into our research collective and enrich the overall analysis.
Raman spectroscopy as a detection and analysis tool for in vitro specific targeting of pancreatic cancer cells by EGF‐conjugated, single‐walled carbon nanotubes
Authors: Karmakar Alokita , Iancu Cornel , Bartos Dana Monica , Mahmood Meena W. , Ghosh Anindya , Xu Yang , Dervishi Enkeleda , Collom Samuel L. , Khodakovskaya Mariya , Mustafa Thikra , Watanabe Fumiya , Biris Alexandru R. , Zhang Yongbin , Ali Syed F. , Casciano Dan , Hassen Samar , Nima Zeid , Biris Alexandru S.
Published: December 2011

Single‐walled carbon nanotubes (SWCNTs) were covalently linked to epidermal growth factor (EGF) proteins through an esterification process that was found to be responsible for the docking of SWCNTs on the human pancreatic cancer cells (PANC‐1) surface, thus providing a mechanism for the enhanced delivery and internalization of the nanotubes. Micro Raman spectroscopy and enzyme‐linked immunosorbent assay were used to evaluate the delivery process and kinetics of the SWCNTs. In vitro studies indicated that the delivery kinetics of SWCNT–EGF conjugates, at a concentration of 85 µg ml−1, to the PANC‐1 cell surfaces was significant in the first 30 min of incubation, but reached a plateau with time in accordance with the establishment of equilibrium between the association and the dissociation of EGF with the cell receptors. SWCNT–EGF conjugates could act as strong thermal ablation agents and could induce higher percentages of cellular death compared with the nontargeted SWCNTs alone. Copyright © 2011 John Wiley & Sons, Ltd.
Alder‐ene reaction: Aromaticity and activation‐strain analysis
Authors: Fernández Israel , Bickelhaupt F. Matthias
Published: December 2011

We have computationally explored the trend in reactivity of the Alder‐ene reactions between propene and a series of seven enophiles using density functional theory at M06‐2X/def2‐TZVPP. The reaction barrier decreases along the enophiles in the order H2CCH2> HCCH > H2CNH > H2CCH(COOCH3) > H2CO > H2CPH > H2CS. Thus, barriers drop in particular, if third‐period atoms become involved in the double bond of the enophile. Activation‐strain analyses show that this trend in reactivity correlates with the activation strain associated with deforming reactants from their equilibrium structure to the geometry they adopt in the transition state. We discuss the origin of this trend and its relationship with the extent of synchronicity between H transfer from ene to enophile and the formation of the new CC bond. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Differential nanofiller cluster formations in dental adhesive systems
Authors: Osorio Estrella , Toledano Manuel , Yamauti Monica , Osorio Raquel
Published: December 2011

Nanofillers are added to dental adhesives to improve mechanical properties of the hybrid layer. Ethanol or water added to the demineralized dentin to improve adhesive infiltration may produce filler aggregation. OBJECTIVE: To assess the effect of 5 vol% water or ethanol addition on nanoparticles distribution in dental adhesives. METHODS: Six available commercial adhesives systems were selected: Clearfil SE Bond (CSE), Clearfil Protect Bond (CPB), FL‐Bond (FLB), Clearfil S3 (CS3), Bond Force (BF), One Up Bond F plus (OUB), and an experimental adhesive system without filler (EXP). Polymer films were obtained by adding 0 (control) or 5 vol% water or ethanol into the bonding resins. Preparations were light‐cured (40 s). Three specimens were analyzed for each mixture. Three phases and 3D images were taken from each specimen by means of an atomic force microscope in taping mode (TM/AFM). Cluster sizes and surface nanoroughness were assessed. RESULTS: Control specimens from CSE, FLB, OUB, and BF presented clusters. The addition of solvents lead to particles aggregation in tested bonding resins. Ethanol addition produced more aggregates, particularly in adhesives containing fluoraluminosilicate as fillers. CONCLUSIONS: Nanofillers aggregation occurred in all adhesive systems in presence of additional solvents. In general, aggregate sizes were higher after the addition of ethanol. Formed clusters size values are always above the dimensions of the spaces existing between the demineralized collagen fibers. Microsc. Res. Tech. 75:749–757, 2012. © 2011 Wiley Periodicals, Inc.