bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural Changes Upon Oxidation of (PtBu2)2 and 1,4‐(CH2)2(PtBu)4: Transannular P–P Interactions in Cations of the 1,4‐C2P4 Ring
Authors: Elder Philip J. W. , Roemmele Tracey L. , Taghavikish Mona , Engesser Tobias A. , Scherer Harald , Krossing Ingo , Boeré René T. , Chivers Tristram
Published: June 2014

Density functional theory (DFT) calculations for the six‐membered ring 1,4‐(CH2)2(PtBu)4 (1), the dimer (PtBu2)2 (2) and the 2,5‐chalcogenated derivatives of 1, 3a (E = S) and 3b (E = Se), and the corresponding cation radicals and dications predict significant structural changes upon oxidation. The formation of a transannular P–P single bond (ca. 2.25 Å) in the three cyclic dications 12+, 3a2+, and 3b2+ is indicated by geometry and consideration of the frontier orbitals. The calculations also indicate a weak transannular interaction in the cyclic cation radicals. The nature of these transannular P–P bonding interactions is analyzed through a consideration of the molecular orbitals involved. Cyclic Voltammetry studies of 1 and 2 reveal two well‐separated oxidation processes. Both processes are irreversible for 1 at normal scan rates, whereas for 2 the first process is quasi‐reversible. The cation radical 1+• could not be detected by in situ electron paramagnetic resonance studies of the first electrochemical oxidation, but a spectrum for the radical cation 2+• could be observed. The difference in the redox behavior of 1 and 2 is considered with respect to the structural parameters and DFT calculations. Chemical oxidation of 1 with NO+[Al(ORF)4]− (RF = C(CF3)3) in CH2Cl2 led to a complex mixture; the protonated cation H1+ (1,4‐(CH2)2(PtBu)3(HPtBu)+) was identified as one of the major products on the basis of multinuclear NMR spectra.
Emerging roles of Notch signaling in liver disease
Authors: Geisler Fabian , Strazzabosco Mario
Published: June 2014

This review critically discusses the most recent advances in the role of Notch signaling in liver development, homeostasis, and disease. It is now clear that the significance of Notch in determining mammalian cell fates and functions extends beyond development, and Notch is a major regular of organ homeostasis. Moreover, Notch signaling is reactivated upon injury and regulates the complex interactions between the distinct liver cell types involved in the repair process. Notch is also involved in the regulation of liver metabolism, inflammation, and cancer. The net effects of Notch signaling are highly variable and finely regulated at multiple levels, but also depend on the specific cellular context in which Notch is activated. Persistent activation of Notch signaling is associated with liver malignancies, such as hepatocellular carcinoma with stem cell features and intrahepatic cholangiocarcinoma. The complexity of the pathway provides several possible targets for agents able to inhibit Notch. However, further cell‐ and context‐specific in‐depth understanding of Notch signaling in liver homeostasis and disease will be essential to translate these concepts into clinical practice and be able to predict benefits and risks of evolving therapies. (Hepatology 2015;61:382–392)
Interruption of KLF5 acetylation converts its function from tumor suppressor to tumor promoter in prostate cancer cells
Authors: Li Xin , Zhang Baotong , Wu Qiao , Ci Xinpei , Zhao Ranran , Zhang Zhiqian , Xia Siyuan , Su Dan , Chen Jie , Ma Gui , Fu Liya , Dong Jin‐Tang
Published: June 2014

KLF5 possesses both tumor suppressing and tumor promoting activities, though the mechanism controlling these opposing functions is unknown. In cultured noncancerous epithelial cells, KLF5 converts from proproliferative to antiproliferative activity upon TGFβ‐induced acetylation, which sequentially alters the KLF5 transcriptional complex and the expression of genes such as p15 and MYC. In this study, we tested whether the acetylation status of KLF5 also determines its opposing functions in tumorigenesis using the PC‐3 and DU 145 prostate cancer cell lines, whose proliferation is inhibited by TGFβ. KLF5 inhibited the proliferation of these cancer cells, and the inhibition was dependent on KLF5 acetylation. MYC and p15 showed the same patterns of expression change found in noncancerous cells. In nude mice, KLF5 also suppressed tumor growth in an acetylation‐dependent manner. Furthermore, deacetylation switched KLF5 to tumor promoting activity, and blocking TGFβ signaling attenuated the tumor suppressor activity of KLF5. RNA sequencing and comprehensive data analysis suggest that multiple molecules, including RELA, p53, CREB1, MYC, JUN, ER, AR and SP1, mediate the opposing functions of AcKLF5 and unAcKLF5. These results provide novel insights into the mechanism by which KLF5 switches from antitumorigenic to protumorigenic function and also suggest the roles of AcKLF5 and unAcKLF5, respectively, in the tumor suppressing and tumor promoting functions of TGFβ.
Raman spectrum of NaAlSi2O6 jadeite. A quantum mechanical simulation
Authors: Prencipe Mauro , Maschio Lorenzo , Kirtman Bernard , Salustro Simone , Erba Alessandro , Dovesi Roberto
Published: June 2014

The Raman spectrum of NaAlSi2O6 jadeite is simulated and compared with two recent experimental data sets. In one experiment, only 17 (out of 30 symmetry allowed) peaks and a qualitative estimate of the intensities are provided. In the second case, the digitalized spectrum is available, from which we have been able to extract 20 evident peaks and an estimate of the relative intensities. The present calculation is based on an ab initio quantum mechanical treatment. Using an all‐electron Gaussian‐type basis set, together with the hybrid B3LYP density functional, the full set of 30 active modes and their (polycrystalline and polarized) intensities are obtained. The simulated intensities (not available in a previous study of the same system) permit the two experimental spectra to be reconciled and explain why the missing peaks were not seen. This ultimately leads to excellent agreement between experiment and theory. By artificially varying the mass of the Na +  and Al3 +  cations in the simulations, which can be performed automatically and at essentially no computational cost, the vibrational modes to which these ions contribute are identified. We conclude that quantum mechanical simulation can be a very useful complementary tool for the interpretation of experimental Raman spectra. Copyright © 2014 John Wiley & Sons, Ltd.
Effect of pre‐harvest methyl jasmonate treatments on ethylene production, water‐soluble phenolic compounds and fruit quality of Japanese plums
Authors: Ozturk Burhan , Yıldız Kenan , Kucuker Emine
Published: June 2014

BACKGROUND

The effects of pre‐harvest methyl jasmonate (MJ) treatments on ethylene production, respiration rate, bioactive compounds and physico‐chemical parameters of plum fruits (Prunus salicina Lindell cv. ‘Fortune’ and ‘Friar’) were investigated. Whole trees were sprayed once with an aqueous solution containing MJ (0, 1120 and 2240 mg L−1) 2 weeks before the anticipated commercial harvest for each cultivar.

RESULTS

In both plum cultivars, 1120 mg L−1 MJ significantly increased hue angle of fruits. The fruit mass and geometric mean diameter were lower in MJ treatments while flesh firmness was higher, except at initial harvest date. Soluble solids concentration increased and titratable acidity decreased with MJ treatments. MJ‐treated fruits exhibited higher levels of ethylene production and respiration rate. MJ was more effective in increasing water‐soluble antioxidant activity, water‐soluble phenolics and individual phenolics. Chlorogenic acid, caffeic acid, rutin, ferulic acid, naringenin and kaempferol contents significantly increased with 2240 mg L−1 MJ.

CONCLUSIONS

This study revealed that pre‐harvest MJ treatments were effective in delaying softening of late‐harvested fruits and increasing bioactive compounds of plum fruits. © 2014 Society of Chemical Industry
Comparison of three modifications of fused‐silica capillaries and untreated capillaries for protein profiling of maize extracts by capillary electrophoresis
Authors: Pobozy Ewa , Sentkowska Aleksandra , Piskor Anna
Published: June 2014

In this work, capillary electrophoresis was applied to protein profiling of fractionated extracts of maize. A comparative study on the application of uncoated fused‐silica capillaries and capillaries modified with hydroxypropylmethylcellulose, ω‐iodoalkylammonium salt and a commercially available neutral capillary covalently coated with polyacrylamide is presented. The coating stability, background electrolyte composition, and separation efficiency were investigated. It was found that for zeins separation, the most stable and efficient was the capillary coated with polyacrylamide. Finally, the usefulness of these methods was studied for the differentiation of zein fraction in transgenic and nontransgenic maize. Zeins extracted from maize standards containing 0 and 5% m/m genetic modification were successfully separated, but slight differences were observed in terms of the zein content. Albumin and globulin fractions were analyzed with the use of unmodified fused‐silica capillary with borate buffer pH 9 and the capillary coated with polyacrylamide with phosphate buffer pH 3. In the albumin fraction, additional peaks were found in genetically modified samples.
Simultaneous determination of citrulline and arginine in human blood plasma by capillary electrophoresis with ultraviolet absorption detection
Authors: Forteschi Mauro , Sotgia Salvatore , Pintus Gianfranco , Zinellu Angelo , Carru Ciriaco
Published: June 2014

A new capillary electrophoresis method to measure human blood plasma arginine and citrulline levels in a single run without derivatization was established. After adding homoarginine as internal standard, plasma proteins were removed by a 90:10 v/v acetonitrile/ammonia mixture. Arginine and citrulline were detected by an ultraviolet detector at 190 nm and separated in 11.65 and 20.43 min, respectively, by using a 75 mmol/L Tris phosphate solution at pH 1.2 as a background electrolyte. Limits of detection were 0.8 and 5 μmol/L for arginine and citrulline, respectively. Precision tests indicated a good repeatability of migration times and of peak area both for citrulline (CV% = 0.82 and 3.19) and arginine (CV% = 0.65 and 2.79). The CV% for intra‐ and interassay tests were, respectively, 1.84 and 3.23 for citrulline and 1.25 and 1.50 for arginine. Mean recovery was 101.5 and 98.5% for citrulline and arginine, respectively. The performance of the developed method was assessed by measuring plasma arginine levels in 52 subjects and the data were compared with those obtained by our previous assay. The new method was then applied to assess plasma citrulline and arginine in ten chronic kidney disease patients under hypolipidemic therapy with statin.
Mitigating Gender Inequality in Rural Regions: The Effects of Tourism Employment in Namibia
Authors: Khatiwada Lila Kumar , Silva Julie A.
Published: June 2014

We examine the effects of tourism employment on gender inequality in Namibia. We find that tourism contributes to local livelihoods by providing opportunities for cash income through employment, craft sales and shareholder profits from tourism enterprises. In general, male‐headed households are economically better off. Female‐headed households with tourism employment are better off than those without and are as equally well‐off as male‐headed households. We find no significant statistical difference between male‐headed households with tourism employment and those without it. These findings suggest that tourism provides specific advantages for women and helps mitigate gender inequality in areas where tourism employment is available. Copyright © 2014 John Wiley & Sons, Ltd.
Plasmonic and metamaterial structures as electromagnetic absorbers
Authors: Cui Yanxia , He Yingran , Jin Yi , Ding Fei , Yang Liu , Ye Yuqian , Zhong Shoumin , Lin Yinyue , He Sailing
Published: June 2014

Electromagnetic absorbers have drawn increasing attention in many areas. A series of plasmonic and metamaterial structures can work as efficient narrowband absorbers due to the excitation of plasmonic or photonic resonances, providing a great potential for applications in designing selective thermal emitters, biosensing, etc. In other applications such as solar‐energy harvesting and photonic detection, the bandwidth of light absorbers is required to be quite broad. Under such a background, a variety of mechanisms of broadband/multiband absorption have been proposed, such as mixing multiple resonances together, exciting phase resonances, slowing down light by anisotropic metamaterials, employing high loss materials and so on.
Fabrication of Durable Honeycomb‐Patterned Films of Poly(ether sulfone)s via Breath Figures
Authors: Liu Yuanyuan , Ma Hengyu , Tian Ye , Xie Fucheng , Wang Xiaolin
Published: June 2014

Honeycomb‐patterned porous films of poly(ether sulfone) (PES) are prepared via breath figures (BF), in which dichloromethane (DCM) is used as the solvent, although the solubility of PES in DCM is relatively low. It is found that the use of a DCM suspension of PES as the casting solution and the addition of an amphiphilic block copolymer, poly(styrene‐co‐maleic acid) partial isobutyl ester (PSME), assist the stabilization of water‐droplet arrays during the BF process, contributing to improved pattern regularity, and finally leading to the formation of highly ordered honeycomb‐patterned films of PES. A synergetic effect of concentration and humidity on the film morphology is discovered and systematically investigated. Moreover, the resultant films possess enhanced resistance to strong acid and base solutions under heating, indicating their promising applications under harsh conditions.

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Fully Biobased Unsaturated Aliphatic Polyesters from Renewable Resources: Enzymatic Synthesis, Characterization, and Properties
Authors: Jiang Yi , van Ekenstein Gert O. R. Alberda , Woortman Albert J. J. , Loos Katja
Published: June 2014

Fully biobased saturated and unsaturated aliphatic polyesters and oligoesters are successfully prepared by Candida antarctica lipase B (CALB)‐catalyzed polycondensations of succinate, itaconate, and 1,4‐butanediol. The effects of monomer substrates and polymerization methods on enzymatic polycondensation are investigated. The CALB‐catalyzed polycondensations of succinic acid, itaconic acid, and 1,4‐butanediol only yield oligomers. By replacing the unactivated dicarboxylic acids with the alkyl diesters, polyesters with various chemical compositions are successfully obtained. The molar compositions and molecular weights of poly(butylene succinate‐co‐itaconate) (PBSI) are significantly affected by the applied polymerization method. Compared with the two‐stage enzymatic polymerization in bulk and in diphenyl ether, the enzymatic azeotropic polymerization in the mixture of cyclohexane and toluene is the best method to synthesize high‐molecular‐weight PBSI with tunable molar compositions. The 13C NMR study reveals that CALB is capable of producing more I‐B‐I‐3 microstructures in the mixture of cyclohexane and toluene by azeotropic distillation. Moreover, the crystalline properties of the obtained polyesters are characterized by wide‐angle X‐ray diffraction (WAXD) and DSC. Furthermore, the thermal and mechanical properties of the crosslinked PBSI are studied.

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ADMET Polymerization of Amino‐Acid‐Based Diene
Authors: Führer Felix N. , Schlaad Helmut
Published: June 2014

1,4‐Di(homo)allyl‐2,5‐diketopiperazines are synthesized and polymerized via ADMET using the Hoveyda–Grubbs 2nd generation catalyst. The but‐3‐enylated diketopiperazine can be converted into unsaturated tertiary polyamide with molar mass of <3000 g mol−1, whereas the allylated diketopiperazine cannot. Double‐bond isomerization occurs regardless of whether or not benzoquinone is present. A polyesteramide with a higher molar mass of ca. 4800 g mol−1 is obtained by the alternating copolymerization (ALTMET) of 1,4‐di(but‐3‐enyl)‐2,5‐diketopiperazine and ethylene glycol diacrylate. A post‐polymerization modification of the poly(ester)amides via radical thiol‐ene chemistry, however, fails.

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Novel SiO2‐Supported Silyl‐Chromate(Cr)/Imido‐Vanadium(V) Bimetallic Catalysts Producing Polyethylene and Ethylene/1‐Hexene Copolymers with Bimodal Molecular‐Weight Distribution
Authors: Zhao Ning , Cheng Ruihua , He Xuelian , Liu Zhen , Liu Boping , Zhang Rui , Gao Yuxin , Zou Enguang , Wang Sihan
Published: June 2014

Novel SiO2‐supported silyl‐chromate(Cr)/imido‐vanadium(V) (Cr‐imidoV) bimetallic catalysts for ethylene and ethylene/α‐olefin polymerization are investigated. These catalysts are prepared using the residual surface hydroxyl groups in SiO2‐supported imido‐vanadium catalysts to further support bis(triphenylsilyl) chromate (BC) in order to get the merits from both the SiO2‐supported imido vanadium catalyst and the SiO2‐supported silyl chromate S‐2 catalyst. By investigation of the polymerization behavior and the microstructures of their polymers, several vital factors such as the addition amount of imido vanadium active centers and the dosage of 1‐hexene in the ethylene homopolymerization and ethylene/1‐hexene copolymerization are systematically investigated. Compared with the traditional S‐2 catalyst and our previously reported SiO2‐supported silyl‐chromate(Cr)/vanadium(V)‐oxide (Cr‐V) bimetallic catalyst, the novel Cr‐imidoV bimetallic catalysts show even higher activity and better 1‐hexene incorporation ability, together with higher molecular weight (MW) and bimodal molecular‐weight distribution (MWD).

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A partially penalty immersed interface finite element method for anisotropic elliptic interface problems
Authors: An Na , Chen Huan‐zhen
Published: June 2014

In this article, we develop a partially penalty immersed interface finite element (PIFE) method for a kind of anisotropy diffusion models governed by the elliptic interface problems with discontinuous tensor‐coefficients. This method is based on linear immersed interface finite elements (IIFE) and applies the discontinuous Galerkin formulation around the interface. We add two penalty terms to the general IIFE formulation along the sides intersected with the interface. The flux jump condition is weakly enforced on the smooth interface. By proving that the piecewise linear function on an interface element is uniquely determined by its values at the three vertices under some conditions, we construct the finite element spaces. Therefore, a PIFE procedure is proposed, which is based on the symmetric, nonsymmetric or incomplete interior penalty discontinuous Galerkin formulation. Then we prove the consistency and the solvability of the procedure. Theoretical analysis and numerical experiments show that the PIFE solution possesses optimal‐order error estimates in the energy norm and
norm.© 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1984–2028, 2014
An Improved Rapid Mixing Device for Time‐Resolved Electrospray Mass Spectrometry Measurements
Authors: Zinck Nicholas , Stark Ann-Kathrin , Wilson Derek J. , Sharon Michal
Published: June 2014

Time series data can provide valuable insight into the complexity of biological reactions. Such information can be obtained by mass‐spectrometry‐based approaches that measure pre‐steady‐state kinetics. These methods are based on a mixing device that rapidly mixes the reactants prior to the on‐line mass measurement of the transient intermediate steps. Here, we describe an improved continuous‐flow mixing apparatus for real‐time electrospray mass spectrometry measurements. Our setup was designed to minimize metal–solution interfaces and provide a sheath flow of nitrogen gas for generating stable and continuous spray that consequently enhances the signal‐to‐noise ratio. Moreover, the device was planned to enable easy mounting onto a mass spectrometer replacing the commercial electrospray ionization source. We demonstrate the performance of our apparatus by monitoring the unfolding reaction of cytochrome C, yielding improved signal‐to‐noise ratio and reduced experimental repeat errors.
Differential activation of placental unfolded protein response pathways implies heterogeneity in causation of early‐ and late‐onset pre‐eclampsia
Authors: Yung Hong Wa , Atkinson Daniel , Campion‐Smith Tim , Olovsson Matts , Charnock‐Jones D Stephen , Burton Graham J
Published: June 2014

Based on gestational age at diagnosis and/or delivery, pre‐eclampsia (PE) is commonly divided into early‐onset (<34 weeks) and late‐onset (≥34 weeks) forms. Recently, the distinction between ‘placental’ and ‘maternal’ causation has been proposed, with ‘placental’ cases being more frequently associated with early‐onset and intrauterine growth restriction. To test whether molecular placental pathology varies according to clinical presentation, we investigated stress‐signalling pathways, including unfolded protein response (UPR) pathways, MAPK stress pathways, heat‐shock proteins and AMPKα in placentae delivered by caesarean section for clinical indications at different gestational ages. Controls included second‐trimester, pre‐term and normal‐term placentae. BeWo cells were used to investigate how these pathways react to different severities of hypoxia–reoxygenation (H/R) and pro‐inflammatory cytokines. Activation of placental UPR and stress‐response pathways, including P‐IRE1α, ATF6, XBP‐1, GRP78 and GRP94, P‐p38/p38 and HSP70, was higher in early‐onset PE than in both late‐onset PE and normotensive controls (NTCs), with a clear inflection around 34 weeks. Placentae from ≥ 34 weeks PE and NTC were indistinguishable. Levels of UPR signalling were similar between second‐trimester and term controls, but were significantly higher in pre‐term ‘controls’ delivered vaginally for chorioamnionitis and other conditions. Severe H/R (1/20% O2) induced equivalent activation of UPR pathways, including P‐eIF2α, ATF6, P‐IRE1α, GRP78 and GRP94, in BeWo cells. By contrast, the pro‐inflammatory cytokines TNFα and IL‐1β induced only mild activation of P‐eIF2α and GRP78. AKT, a central regulator of cell proliferation, was reduced in the < 34 weeks PE placentae and severe H/R‐treated cells, but not in other conditions. These findings provide the first molecular evidence that placental stress may contribute to the pathophysiology of early‐onset pre‐eclampsia, whereas that is unlikely to be the case in the late‐onset form of the syndrome. © 2014 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
Adhesive bonding for mechanically stacked solar cells
Authors: Mathews Ian , O'Mahony Donagh , Thomas Kevin , Pelucchi Emanuele , Corbett Brian , Morrison Alan P.
Published: June 2014

Mechanically stacked solar cells formed using adhesive bonding are proposed as a route to high‐efficiency devices as they enable the combination of a wide range of materials and bandgaps. The concept involves adhesive bonding of subcells using polymeric materials widely used in semiconductor processing and outlines how the absolute efficiency can be maximised by optimisation of the adhesive layer thickness and optical matching of the adhesive layer with both the subcells and their anti‐reflection coatings. A dual‐junction, GaAs‐InGaAs, mechanically stacked solar cell is demonstrated using a benzocyclobutene adhesive layer with a measured PV conversion efficiency of 25.2% under 1‐sun AM1.5G conditions. Copyright © 2014 John Wiley & Sons, Ltd.
Employing microsecond pulses to form laser‐fired contacts in photovoltaic devices
Authors: Raghavan Ashwin S. , Palmer Todd A. , Kragh‐Buetow Katherine C. , Domask Anna C. , Reutzel Edward W. , Mohney Suzanne E. , DebRoy Tarasankar
Published: June 2014

Laser‐fired contacts (LFCs) are typically fabricated with nanosecond pulse durations despite the fact that extremely precise and costly control of the process is necessary to prevent significant ablation of the aluminum metallization layer. Microsecond pulse durations offer the advantage of reduced metal expulsion and can be implemented with diffractive optics to process multiple contacts simultaneously and meet production demands. In this work, the influence of changes in laser processing parameters on contact morphology, resistance, and composition when using microsecond pulses has been fully evaluated. Simulated and experimental results indicate that contacts are hemispherical or half‐ellipsoidal in shape. In addition, the resolidified contact region is composed of a two‐phase aluminum–silicon microstructure that grows from the single‐crystal silicon wafer during resolidification. As a result, the total contact resistance is governed by the interfacial contact area for a three‐dimensional contact geometry rather than the planar contact area at the aluminum–silicon interface in the passivation layer opening. The results also suggest that for two LFCs with the same size top surface diameter, the contact produced with a smaller beam size will have a 25–37% lower contact resistance, depending on the LFC diameter, because of a larger contact area at the LFC/wafer interface. Copyright © 2014 John Wiley & Sons, Ltd.
Halogen bond symmetry: the N–X–N bond
Authors: Hakkert Sebastiaan B. , Erdélyi Máté
Published: June 2014

Halogen bonding is the attractive interaction of an electrophilic region of a halogen with a nucleophile. Its geometry, energy, and dominantly electrostatic nature resemble that of the hydrogen bond. Halogen bond strength critically depends on the electron deficiency of the halogen. Accordingly, halonium ions that bear a formal positive charge are the strongest halogen bond donors known so far. Halonium ions, similar to H+, are capable of simultaneously interacting with two Lewis bases. The structure and properties of the resulting three‐center halogen bonds are reviewed herein, based on their spectroscopic and computational data, with the emphasis being placed on one representative example, the [N–X−N]+ interaction. The iodine and bromine‐centered systems form symmetric three‐center‐four‐electron halogen bonds that have comparable orbital and electrostatic contributions and a large extent of charge delocalization. Their formation yields significant stabilization. The [N–Cl–N]+ bond is computationally predicted to resemble the symmetry of the three‐center bond of the heavier halogens, whereas the fluorine‐centered halogen bond is predicted to be asymmetric, and thus behave more similar to the analogous, asymmetric three‐center [N−H−N]+ hydrogen bond. Experimental confirmation of the latter predictions remains to be accomplished, along with studies of the possible influence of the disorder of the local environment on halogen bond symmetry, and investigations in the gaseous phase. The electronic structure and the geometry of three‐center halogen bonds are of fundamental interest, and also of practical importance, for example due to the occurrence of three‐centered halogen bonds in synthetic reagents. Copyright © 2014 John Wiley & Sons, Ltd.
Pyromellitic diimide‐based copolymers for ambipolar field‐effect transistors: Synthesis, characterization, and device applications
Authors: Shao Jinjun , Chang Jingjing , Dai Gaole , Chi Chunyan
Published: June 2014

A pyromellitic diimide building block, 2,6‐bis(2‐decyltetradecyl)−4,8‐di(thiophen‐2‐yl)pyrrolo[3,4‐f]isoindole‐1,3,5,7(2H,6H)‐tetraone (4), is synthesized. Based on this building block and other electron‐rich units such as 2,2′‐bithiophene, thieno[3,2‐b]thiophene and 4,8‐bis(dodecyloxy)benzo[1,2‐b:4,5‐b′]dithiophene, three conjugated polymers P1, P2, and P3 are prepared in good yield via Stille coupling polymerization. These new copolymers have good solubility in common organic solvents and exhibit good thermal stability. The optical, electrochemical, and thermal properties of these polymers P1–P3 are carefully investigated, and their applications in solution‐processed organic field‐effect transistors are also studied. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 2454–2464
Thiol‐ene and thiol‐yne‐based synthesis of glycodendrimers as nanomolar inhibitors of wheat germ agglutinin
Authors: Ghirardello Mattia , Öberg Kim , Staderini Samuele , Renaudet Olivier , Berthet Nathalie , Dumy Pascal , Hed Yvonne , Marra Alberto , Malkoch Michael , Dondoni Alessandro
Published: June 2014

Alkene and alkyne functional polyester‐based dendrimers of generation 1 to 4 have been prepared and reacted under free‐radical conditions with 2‐acetamido‐2‐deoxy‐1‐thio‐β‐D‐glucose (GlcNAc‐SH). As the alkene‐dendrimers underwent the addition of one thiyl radical per ene group whereas each yne group of alkyne‐dendrimers was saturated by two thiyl radicals, a collection of glycodendrimers with glycan density ranging from six to ninety‐six GlcNAc per dendrimer was obtained. The recognition properties of the prepared glycodendrimers toward the wheat germ agglutinin (WGA) were evaluated by enzyme‐linked lectin assay (ELLA). The eight glycodendrimers were excellent ligands showing IC50 values in the nanomolar range and relative potencies per sugar unit up to 2.27 e6 when compared to monosaccharidic GlcNAc used as monovalent reference. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 2422–2433
Patterns and predictors of antidepressant use in ambulatory cancer patients with common solid tumors
Authors: Fisch Michael J. , Zhao Fengmin , Manola Judith , Miller Andrew H. , Pirl William F. , Wagner Lynne I.
Published: June 2014

Purpose

Depressive symptoms and antidepressant use are prevalent among cancer patients. We sought to identify determinants of prescribing commonly used antidepressants.

Patients and methods

This multi‐institutional study enrolled 3106 ambulatory patients with cancer of the breast, prostate, colon/rectum, or lung. Five case‐finding methods were used to identify patients with depressive symptoms. Logistic models were used to examine factors that impact antidepressant use.

Results

Approximately, 47% of patients were defined as having depressive symptoms. Clinicians rated being sad/depressed as one of the top three priority problems for 10.5% of patients. Antidepressants were prescribed in 19% of all patients, 25% with depressive symptoms and 14% nondepressed patients. After adjusting for other covariates, these variable categories were significantly associated with greater use of antidepressants: depressive symptoms, family history of depression, concurrent medication use, cancer treatment status, and certain other clinical and demographic variables. The strongest individual predictors were concurrent use of more than 10 medications (odds ratio [OR] = 3.3), a family history of depression (OR = 2.2), sedative use (OR = 2.1), non‐Hispanic white race (OR = 2.0), and anxiolytics use (OR = 2.0).

Conclusions

Depressive symptoms are found in nearly half of outpatients with cancer, and one‐fourth of patients with depressive symptoms are taking an antidepressant. Patients receiving antidepressants are more often those taking multiple medications, those with a depression diathesis, and those with more extensive cancer treatment. Patients who were younger, white, and female were also more likely to be taking antidepressants. Copyright © 2014 John Wiley & Sons, Ltd.
Assessing the needs of informal caregivers to cancer survivors: a review of the instruments
Authors: Prue Gillian , Santin Olinda , Porter Sam
Published: June 2014

Objective

Cancer may impact negatively on an informal caregiver's health long after treatment has ended. This review identifies the self‐report measures currently in use to measure caregivers need for support and determines their scientific soundness and clinical utility.

Method

A systematic electronic database search of Medline, CINAHL, PsychINFO, BNI ProQuest was conducted. The psychometric properties and clinical utility of needs assessment tools for caregivers of cancer survivors (excluding advanced disease) were extracted and summarised.

Results

Seven cancer survivor caregiver needs assessment tools were identified. Data on instrument development was well reported, although variability was noted in their structure and content. The majority demonstrated some degree of reliability and validity; only two were evaluated for test–retest reliability (CaSPUN and SPUNS) with only the SPUNS showing a high degree of reliability over time. The Health Care Needs Survey (HCNS), Needs Assessment of Family Caregivers‐Cancer (NAFC‐C) and Cancer Caregiving Tasks Consequences and Needs Questionnaire (CaTCoN) have been validated at various stages of the cancer continuum. Minimal data was available on responsiveness.

Conclusion

All assessment tools identified require further psychometric analysis. For research purposes, the use of the SPUNS (with its acceptable test–retest reliability) appears most appropriate; although its length may be of concern for clinical use; therefore, the shorter SCNS‐P&C is likely to be more suitable for use clinically. At present, the NAFC‐C demonstrates a great potential in both the research and clinical environments; however, it requires further psychometric testing before it can be fully recommended. Further analysis is necessary on ideal response formats and the meaning of a total needs score. Copyright © 2014 John Wiley & Sons, Ltd.
Gait Changes with Balance‐Based Torso‐Weighting in People with Multiple Sclerosis
Authors: Gorgas Anna‐Maria , Widener Gail L. , Gibson‐Horn Cynthia , Allen Diane D.
Published: June 2014

Background and Purpose

People with multiple sclerosis (PwMS) commonly have mobility impairments that may lead to falls and limitations in activities. Physiotherapy interventions that might improve mobility typically take several weeks. Balance‐based torso‐weighting (BBTW), a system of strategically placing light weights to improve response to balance perturbations, has resulted in immediate small improvements in clinical measures in PwMS, but changes in spatiotemporal gait parameters are unknown. The purpose was to investigate the effects of BBTW on gait parameters in PwMS and healthy controls.

Methods

Design

This study is a non‐randomized controlled experiment.

Participants

This study included 20 PwMS and 20 matched healthy controls

Procedures

People with multiple sclerosis walked on an instrumented mat at their fastest speed for three trials each in two conditions: without BBTW then with BBTW. Healthy controls walked in both conditions at two speeds: their fastest speed and at velocities equivalent to their matched PwMS.

Results

Averaged gait trials showed that, with BBTW, PwMS had significantly increased velocity (p = 0.002), cadence (p = 0.007) and time spent in single‐limb support (p = 0.014), with decreased time in double‐limb support (p = 0.004). Healthy controls increased velocity (p = 0.012) and cadence (p = 0.015) and decreased support base (p = 0.014) in fast trials with BBTW; at matched velocities, step length (p = 0.028) and support base (p = 0.006) were significantly different from PwMS. All gait variables in healthy controls at fast speeds were significantly different from PwMS walking at their fastest speeds.

Discussion

All participants showed increases in gait velocity and cadence during fast walk with BBTW. Improvements in time spent in single‐limb and double‐limb support by PwMS with BBTW may reflect greater stability in gait. Future research might ascertain if these immediate improvements could enhance effectiveness of longer‐term physiotherapy on functional mobility in PwMS. Copyright © 2014 John Wiley & Sons, Ltd.
Post‐War Migration Flows and Disparities in Mortality from Age 50 Years Onwards: the Case of Turin in Italy
Authors: Zarulli Virginia
Published: June 2014

Compositional changes due to internal migration can modify the distribution of health outcomes, death rates, and socio‐economic characteristics of a specific geographical area. Migration flows may affect patterns of socio‐economic inequalities in mortality as well. However, despite these inequalities being an important social and geopolitical feature of an area, there is still little empirical evidence on this effect. This paper contributes to deepening the knowledge about this phenomenon by investigating whether post‐war internal migration in Italy affected the pattern of mortality inequality by socio‐economic status, from age 50 years onwards, in Turin, one of the main industrial areas of the country, to which many low‐educated individuals from the southern regions migrated, seeking jobs in the car factories. Migrants might be selected in terms of robustness because of the healthy migrant effect. However, low‐educated individuals are employed in heavier and riskier jobs. They thus undergo a faster health selection due to exposure to a higher mortality risk that selects the most robust individuals. This paper hypothesised that the interplay of these mechanisms might have produced a homogenisation process towards robustness of the population by reducing the unobserved heterogeneity in survival chances and that these processes affected men more than women, because women were likely to be more passive actors in the migratory decisions and less heavily involved in the industrialisation process. The results show that women have higher levels of heterogeneity in susceptibility to death and wider differentials mortality by education level than men, which both support the hypotheses. © 2014 The Authors.Population, Space and Place. Published by John Wiley & Sons, Ltd.
Gelidium elegans, an Edible Red Seaweed, and Hesperidin Inhibit Lipid Accumulation and Production of Reactive Oxygen Species and Reactive Nitrogen Species in 3T3‐L1 and RAW264.7 Cells
Authors: Jeon Hui‐Jeon , Seo Min‐Jung , Choi Hyeon‐Son , Lee Ok‐Hwan , Lee Boo‐Yong
Published: June 2014

Gelidium elegans is an edible red alga native to the intertidal area of northeastern Asia. We investigated the effect of G. elegans extract and its main flavonoids, rutin and hesperidin, on lipid accumulation and the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in 3T3‐L1 and RAW264.7 cells. Our data show that G. elegans extract decreased lipid accumulation and ROS/RNS production in a dose‐dependent manner. The extract also inhibited the mRNA expression of adipogenic transcription factors, such as peroxisome proliferator‐activated receptor gamma and CCAAT/enhancer‐binding protein alpha, while enhancing the protein expression of the antioxidant enzymes superoxide dismutases 1 and 2, glutathione peroxidase, and glutathione reductase compared with controls. In addition, lipopolysaccharide‐induced nitric oxide production was significantly reduced in G. elegans extract‐treated RAW264.7 cells. In analysis of the effects of G. elegans flavonoids on lipid accumulation and ROS/RNS production, only hesperidin showed an inhibitory effect on lipid accumulation and ROS production; rutin did not affect adipogenesis and ROS status. The antiadipogenic effect of hesperidin was evidenced by the downregulation of peroxisome proliferator‐activated receptor gamma, CCAAT/enhancer‐binding protein alpha, and fatty acid binding protein 4 gene expression. Collectively, our data suggest that G. elegans is a potential food source containing antiobesity and antioxidant constituents. Copyright © 2014 John Wiley & Sons, Ltd.
Bayesian Control Chart for Nonconformities
Authors: Raubenheimer L. , van der Merwe A.J.
Published: June 2014

The c‐chart or the control chart for nonconformities is designed for the case where one deals with the number of defects or nonconformities observed. A control chart can be developed for the total or average number of nonconformities per unit, which is well modeled by the Poisson distribution. In this paper the c‐chart will be studied, where the usual operation of the c‐chart will be extended by introducing a Bayesian approach for the c‐chart. Control chart limits, average run lengths, and false alarm rates will be determined by using a Bayesian method. These results will be compared with the results obtained when using the classical (frequentist) method. Copyright © 2014 John Wiley & Sons, Ltd.
Kinetics study of orientation‐dependent surface blistering and exfoliation process in hydrogen‐implanted germanium
Authors: Chien C. C. , Chao D. S. , Liang J. H.
Published: June 2014

This study provided a thorough investigation of surface blistering and exfoliation behavior in germanium substrates with different crystal orientation, which is crucial for understanding the mechanism of smart‐cut process in the fabrication of germanium‐on‐insulator. Two hundred‐kilo‐electron‐volt H2+ ions with a fluence of 2.5 × 1016 ions/cm2 were implanted into (100)‐oriented, (111)‐oriented, and (110)‐oriented n‐type germanium wafers. Following ion implantation, the post‐annealing treatments were conducted to drive the formation of blisters and craters in germanium. In conducting the characteristic analysis, hydrogen depth profiles were measured using SIMS. In situ optical microscopy observation was performed to measure the threshold temperature and onset time of the blisters and craters. Cross‐sectional transmission electron microscopy was also employed to examine the micro‐structural properties of hydrogen‐induced radiation defects in the specimens. The kinetics of the thermally activated blistering process was also analyzed to estimate the effective activation energy for blister and crater formation. The results revealed that an obviously different morphology of the optically detectable blisters and craters can be identified in Ge(100), Ge(111), and Ge(110) specimens. Substrate orientation of germanium also makes a great impact on the blistering threshold temperature, the onset time and activation energy for blister and crater formation, and the development of hydrogen implantation‐induced micro‐cracks. Copyright © 2014 John Wiley & Sons, Ltd.
Recycling Bacteria for the Synthesis of LiMPO4 (M = Fe, Mn) Nanostructures for High‐Power Lithium Batteries
Authors: Zhou Yanping , Yang Dan , Zeng Yi , Zhou Yan , Ng Wun Jern , Yan Qingyu , Fong Eileen
Published: June 2014

In this work, a novel waste‐to‐resource strategy to convert waste bacteria into a useful class of cathode materials, lithium metal phosphate (LiMPO4; M = Fe, Mn), is presented. Escherichia coli (E. coli) bacteria used for removing phosphorus contamination from wastewater are harvested and used as precursors for the synthesis of LiMPO4. After annealing, LiFePO4 and LiMnPO4 nanoparticles with dimensions around 20 nm are obtained. These particles are found to be enveloped in a carbon layer with a thickness around 3–5 nm, generated through the decomposition of the organic matter from the bacterial cell cytoplasm. The battery performance for the LiFePO4 is evaluated. A high discharge capacity of 140 mAh g−1 at 0.1 C with a flat plateau located at around 3.5 V is obtained. In addition, the synthesized particles display excellent stability and rate capabilities. Even under a high C rate of 10 C, a stable discharge capacity of 75.4 mAh g−1 can still be achieved.
Brief report: The Utrecht‐Management of Identity Commitments Scale (U‐MICS): Gender and age measurement invariance and convergent validity of the Turkish version
Authors: Morsunbul Umit , Crocetti Elisabetta , Cok Figen , Meeus Wim
Published: June 2014

The purpose of this study was to evaluate the factor structure and convergent validity of the Turkish version of the Utrecht‐Management of Identity Commitments Scale (U‐MICS). Participants were 1201 (59.6% females) youth aged between 12 and 24 years (Mage = 17.53 years, SDage = 3.25). Results indicated that the three‐factor model consisting of commitment, in‐depth exploration, and reconsideration of commitment provided a very good fit to the data and applied equally well to boys and girls as well as to three age groups (early adolescents, middle adolescents, and emerging adults). Significant relations between identity processes and self‐concept clarity, personality, internalizing and externalizing problem behaviors, and parental relationships supported convergent validity. Thus, the Turkish version of U‐MICS is a reliable tool for assessing identity in Turkish‐speaking respondents.
Unique effects of different components of trait emotional intelligence in traditional bullying and cyberbullying
Authors: Baroncelli Andrea , Ciucci Enrica
Published: June 2014

This study investigated whether different components of trait emotional intelligence (or trait emotional self‐efficacy) were uniquely related to traditional bullying and cyberbullying in a sample of 529 preadolescents (mean age of 12 years and 7 months), while controlling for the other forms of bullying/victimization. Binary logistic regressions showed that the dimension of emotional intelligence concerning the regulation and use of emotions was negatively related both to traditional bullying and cyberbullying; however, this association did not emerge when traditional bullying was controlled for cyberbullying, whilst it still emerged when cyberbullying was controlled for traditional bullying and both forms of victimization. Differently, the dimensions concerning appraisal of own and others' emotions were not deficient in children performing bullying and/or cyberbullying behaviors. Despite high co‐occurrence between traditional and electronic bullying, our results suggested that these two forms are distinct phenomena, involving different personality traits. Implications for interventions are discussed.
Clinical Image Quality in Daily Practice of Breast Cancer Mammography Screening
Authors: Guertin Marie-Hélène , Théberge Isabelle , Dufresne Michel-Pierre , Zomahoun Hervé Tchala Vignon , Major Diane , Tremblay Richard , Ricard Carmen , Shumak Rene , Wadden Nancy , Pelletier Éric , Brisson Jacques
Published: June 2014

Objective

To assess the quality of screening mammograms performed in daily practice in the Quebec Breast Cancer Screening Program.

Subjects and Methods

Clinical image quality of a random subsample of 197 screening mammograms performed in 2004-2005 was independently evaluated by 2 radiologists based on the criteria by Canadian Association of Radiologists (CAR). When disagreement occurred for overall judgement or positioning score, the mammograms were reviewed by a third radiologist. Cohen's kappas for interrater agreement were computed. Multivariable robust Poisson regression models were used to study associations of overall quality and positioning with body mass index (BMI) and breast density.

Results

The CAR criteria were not satisfied for 49.7% of the mammograms. Positioning was the quality attribute most often deficient, with 37.2% of mammograms failing positioning. Interrater agreement ranged from slight (kappa = 0.02 for compression and sharpness) to fair (kappa = 0.30 for exposure). For overall quality, women with a BMI ≥ 30 kg/m2 had a failure proportion of 67.5% compared with 34.9% for women with a BMI<25 kg/m2 (risk ratio 2.1 [95% confidence interval, 1.5-3.0]). For positioning, women with a BMI ≥ 30 kg/m2 had a failure proportion of 53.8% compared with 27.9% for women with a BMI < 25 kg/m2 (risk ratio 1.9 [95% confidence interval, 1.2-3.1]). Effects of breast density on image quality differed among radiologists.

Conclusion

Despite measures to ensure high-quality imaging, including CAR accreditation, approximately half of this random sample of screening mammograms failed the CAR quality standards. It would be important to define quality targets for screening mammograms carried out in daily practice to interpret such observations.
X‐chromosome inactivation in development and cancer
Authors: Chaligné Ronan , Heard Edith
Published: June 2014

X‐chromosome inactivation represents an epigenetics paradigm and a powerful model system of facultative heterochromatin formation triggered by a non‐coding RNA, Xist, during development. Once established, the inactive state of the Xi is highly stable in somatic cells, thanks to a combination of chromatin associated proteins, DNA methylation and nuclear organization. However, sporadic reactivation of X‐linked genes has been reported during ageing and in transformed cells and disappearance of the Barr body is frequently observed in cancer cells. In this review we summarise current knowledge on the epigenetic changes that accompany X inactivation and discuss the extent to which the inactive X chromosome may be epigenetically or genetically perturbed in breast cancer.