bluuebunny/crossref_metadata_2025 huggingface dataset:
Partners of USEPA Climate Leaders: an Event Study on Stock Performance
Authors: Keele Denise M. , DeHart Susan
Published: January 2011

This research utilized an event study method to assess how the stocks of publicly traded companies responded before and after announcing their partnership with the United States Environmental Protection Agency (USEPA) Climate Leaders program. Although the stocks exhibited an average non‐significant positive abnormal return of 0.56% on the day of the announcement, the cumulative abnormal returns for the stock prices of the firms for two of the three event windows showed statistically significant negative returns. These results suggest that these firms' public announcements of joining the USEPA Climate Leaders partnership did not have a positive impact on stock performance. While no immediate financial benefit was found in this research, the practices implemented by these firms to reduce their greenhouse gas emissions may still bode well for long‐term corporate earnings and attractiveness to investors. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.
Continuous Separation of an H2SO4/CuSO4 Mixture by Diffusion Dialysis
Authors: Bendová H. , Palatý Z.
Published: January 2011

The separation of a mixture of sulfuric acid and copper sulfate is experimentally investigated in a two‐compartment countercurrent dialyzer at steady state using an anion‐exchange membrane. The dialysis process is characterized by the recovery yield of acid, the rejection coefficient of salt, and the permeability coefficient of the membrane. The simultaneous transport of sulfuric acid and copper sulfate is quantified by four phenomenological coefficients, which are dependent on the acid and salt concentrations in the feed. They are determined by a procedure consisting of (i) the numerical integration of the basic differential equations describing the concentration profiles of both components on both sides of the membrane and (ii) the optimizing method.
Structural and Binding Study of Modified siRNAs with the Argonaute 2 PAZ Domain by NMR Spectroscopy
Authors: Maiti Mohitosh , Nauwelaerts Koen , Lescrinier Eveline , Herdewijn Piet
Published: January 2011

By using high‐resolution NMR spectroscopy, the structures of a natural short interfering RNA (siRNA) and of several altritol nucleic acid (ANA)‐modified siRNAs were determined. The interaction of modified siRNAs with the PAZ domain of the Argonaute 2 protein ofDrosophila melanogasterwas also studied. The structures show that the modified siRNA duplexes (ANA/RNA) adopt a geometry very similar to the naturally occurring A‐type siRNA duplex. All ribose residues, except for the 3′ overhang, show 3′‐endoconformation. The six‐membered altritol sugar in ANA occurs in a chair conformation with the nucleobase in an axial position. In all siRNA duplexes, two overhanging nucleotides at the 3′ end enhance the stability of the first neighboring base pair by a stacking interaction. The first overhanging nucleotide has a rather fixed position, whereas the second overhanging nucleotide shows larger flexibility. NMR binding studies of the PAZ domain with ANA‐modified siRNAs demonstrate that modifications in the double‐stranded region of the antisense strand have some small effects on the binding affinity as compared with the unmodified siRNA. Modification of the 3′ overhang with thymidine (dTdT) residues shows a sixfold increase in the binding affinity compared with the unmodified siRNA (relative binding affinity of 17 % compared with dTdT‐modified overhang), whereas modification of the 3′ overhang with ANA largely decreases the binding affinity.
Predicting the Relative Stability of Simple versus ansa‐Sandwich Systems Across Groups: Structure, Bonding, and (In)Stability in Tris(sandwich)benzene Complexes
Authors: Donald Kelling J. , Bober Matthew
Published: January 2011

We examine theoretically the bonding and thermodynamic stability of a proposed class of tris(sandwich)benzene complexes with the general formula C6(RMR′)3. In these systems, a single central (benzene) ring is flanked by three distorted 18‐electron sandwich fragments with M = Groups 6, 7, or 8 metals, and R and R′ = Ph or cyclopentadienyl (Cp) substituents. Remarkably, the computed free energy changes for the binding of the metal atoms to the organic fragments in 1) the ansa‐(C6(RMR′)3) complexes and 2) the simple (RMR′) sandwich complexes—for all the Groups 6, 7, and 8 metals—conform to the linear relationship: [ΔGbind(C6(RMR′)3)]/3 = ${\beta {{\Delta G\hfill \atop 1\hfill}}}$[ΔGbind(RMR′)]+${\beta {{\Delta G\hfill \atop 2\hfill}}}$ (R=0.989). The bonding and relative stabilities of these unusual tris(sandwich) and simple sandwich complexes are assessed at the B3PW91 level of theory employing small‐core relativistic MDF pseudopotentials and the corresponding basis sets for all the metals. The possible existence of strain‐induced bond localization (the so‐called Mills–Nixon effect) in the C6(RMR′)3 complexes and the aromaticity at the central benzene ring in C6(RMR′)3 are investigated. Despite the strain on the central ring, no bond fixation is observed. The tris(sandwich) complexes of Groups 6, 7, and 8 are all thermodynamically stable, relative to the free M atoms and organic fragments, with increasing stability as M gets heavier (going down the groups). The equation above also enables us to predict, by extrapolation, the (in)stabilities of the C6(RMR′)3 complexes of several other transition metals and helps us to better understand thermodynamic aspects of the ansa effect. Similar functions likely apply for other ansa variants of sandwich complexes.
Critical In Vitro Evaluation of Responsive MRI Contrast Agents for Calcium and Zinc
Authors: Mishra Anurag , Logothetis Nikos K. , Parker David
Published: January 2011

The synthesis of two gadolinium(III) complexes that exhibit an increase in proton relaxivity in the presence of added Ca2+ or Zn2+ ions is reported. The complexes increase their hydration state from zero to one following metal‐ion binding, confirmed by spectral measurements on the corresponding EuIII complexes. At a field of 1.4 T and 310 K, modulation of relaxivity of the order of 30–40 % was observed in mouse serum in each case. The dissociation constants for Ca2+ and Zn2+ binding were sensitive to the presence of added bicarbonate, and were 450 μM (Ca2+) and 200 μM (Zn2+) in serum. Such systems may, therefore, be considered for use as magnetic resonance imaging (MRI) contrast agents to track the restoration of changes in metal‐ion concentration in the cerebrospinal fluid of the brain, following neural stimulation.
Aurophilicity: The Effect of the Neutral Ligand L on [{ClAuL}2] Systems
Authors: Muñiz Jesús , Wang Cong , Pyykkö Pekka
Published: January 2011

The effect of the ligand L on the aurophilic AuI⋅⋅⋅AuI closed‐shell interaction in perpendicular [{ClAuL}2] model systems is investigated. An analogous study of the effect of the halide X (here Cl) exists, and showed a correlation with the softness of the ligand X. In this work, we study the correlation with L=N‐heterocyclic carbenes (NHC), cyclic diphosphinocarbenes (PHC), NF3, CO, methyl isocyanide CNMe, PF3, SH2, NH3, H2O, pyridine, triazene, the carbodiphosphorene model C(PH3)2, C3H2, and the related model systems CN2 or CP2. The NHCs yield stronger interactions than PH3. The spatial orientation of certain ligands in a “paddle” configuration plays an important role on the strength of the interaction. All are examples on aurophilicity.
Efficient Charge Separation in TiO2 Films Sensitized with Ruthenium(II)–Polypyridyl Complexes: Hole Stabilization by Ligand‐Localized Charge‐Transfer States
Authors: Verma Sandeep , Kar Prasenjit , Das Amitava , Ghosh Hirendra N.
Published: January 2011

We have studied the interfacial electron‐transfer dynamics on TiO2 film sensitized with synthesized ruthenium(II)–polypyridyl complexes—[RuII(bpy)2(L1)] (1) and [RuII(bpy)(L1)(L2)] (2), in which bpy=2,2′‐bipyridyl, L1=4‐[2‐(4′‐methyl‐2,2′‐bipyridinyl‐4‐yl)vinyl]benzene‐1,2‐diol, and L2=4‐(N,N‐dimethylaminophenyl)‐2,2′‐bipyridine—by using femtosecond transient absorption spectroscopy. The presence of electron‐donor L2 and electron‐acceptor L1 ligands in complex 2 introduces lower energetic ligand‐to‐ligand charge‐transfer (LLCT) excited states in addition to metal‐to‐ligand (ML) CT manifolds of complex 2. On photoexcitation, a pulse‐width‐limited (<100 fs) electron injection from populating LLCT and MLCT states are observed on account of strong catecholate binding on the TiO2 surface. The hole is transferred directly or stepwise to the electron‐donor ligand (L2) as a consequence of electron injection from LLCT and MLCT states, respectively. This results an increased spatial charge separation between the hole residing at the electron‐donor (L2) ligand and the electron injected in TiO2 nanoparticles (NPs). Thus, we observed a significant slow back‐electron‐transfer (BET) process in the 2/TiO2 system relative to the 1/TiO2 system. Our results suggest that RuII–polypyridyl complexes comprising LLCT states can be a better photosensitizer for improved electron injection yield and slow BET processes in comparison with RuII–polypyridyl complexes comprising MLCT states only.
Identification of Ligands for the Tau Exon 10 Splicing Regulatory Element RNA by Using Dynamic Combinatorial Chemistry
Authors: López‐Senín Paula , Gómez‐Pinto Irene , Grandas Anna , Marchán Vicente
Published: January 2011

We describe the use of dynamic combinatorial chemistry (DCC) to identify ligands for the stem‐loop structure located at the exon 10‐5′‐intron junction of Tau pre‐mRNA, which is involved in the onset of several tauopathies including frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP‐17). A series of ligands that combine the small aminoglycoside neamine and heteroaromatic moieties (azaquinolone and two acridines) have been identified by using DCC. These compounds effectively bind the stem‐loop RNA target (the concentration required for 50 % RNA response (EC50): 2–58 μM), as determined by fluorescence titration experiments. Importantly, most of them are able to stabilize both the wild‐type and the +3 and +14 mutated sequences associated with the development of FTDP‐17 without producing a significant change in the overall structure of the RNA (as analyzed by circular dichroism (CD) spectroscopy), which is a key factor for recognition by the splicing regulatory machinery. A good correlation has been found between the affinity of the ligands for the target and their ability to stabilize the RNA secondary structure.
Dendritic Oligothiophenes Terminated with Tris(alkyloxy)phenylethynyl Tails: Synthesis, Physical Properties, and Self‐Assembly
Authors: Ma Chang‐Qi , Pisula Wojciech , Weber Cornelia , Feng Xin‐Liang , Müllen Klaus , Bäuerle Peter
Published: January 2011

Three‐dimensional (3D) π‐conjugated dendritic oligothiophenes up to a third generation have been functionalized with tris(decyloxy)phenylethynyl tails at the periphery. The first‐generation compounds (3 T‐p‐Ph‐C10 and 6 T‐p‐Ph‐C10) were synthesized by palladium‐catalyzed Sonogashira coupling reactions, whereas the higher generation products were synthesized by palladium‐catalyzed Suzuki coupling reactions in a divergent approach. The optical and electrochemical properties were investigated by UV/Vis absorption, fluorescence spectroscopy, and cyclic voltammetry. The results revealed that the terminal tris(alkyloxy)phenylethynyl groups are conjugated to the branched oligothiophene core, yielding redshifted absorption and fluorescence spectra and reduced optical band gaps relative to the dendritic oligothiophene core. A structural study revealed a close relationship between the type of supramolecular organization and the size of the oligothiophene core. The first‐generation compounds 3 T‐p‐Ph‐C10 and 6 T‐p‐Ph‐C10 displayed columnar phases in the bulk state, which was confirmed by two‐dimensional wide‐angle X‐ray scattering (2D WAXS) measurements. The self‐assembly into columnar stacks has mainly been attributed to phase separation between the rigid thiophene cores and the flexible side‐chains assisted by minor π‐stacking interactions between the conjugated dendritic oligothiophene units. The high‐generation compounds, however, showed less ordered structures in the solid state.
Density Functional Calculations on the Distribution, Acidity, and Catalysis of TiIV and TiIII Ions in MCM‐22 Zeolite
Authors: Yang Gang , Zhou Lijun , Liu Xianchun , Han Xiuwen , Bao Xinhe
Published: January 2011

Isolated Ti species in zeolites show unique catalytic activities for a variety of chemical reactions. In this work, density functional calculations were used to explore three current concerns: 1) the distributions of TiIV and TiIII ions in the MCM‐22 zeolite; 2) the Lewis acidity of the TiIV and TiIII sites; and 3) activation of alkane CH bonds by photocatalysis with Ti‐doped zeolites. Neither the TiIV nor TiIII ions are randomly distributed in the MCM‐22 zeolite. The orders of relative stability are very close for the eight TiIV and TiIII sites, and the T3 site is the most probable in both cases. The wavelengths for TiIV–TiIII excitations were calculated to lie in the range λ=246.9–290.2 nm. The Ti3IV site shows Lewis acidity toward NH3 in two different modes, and these two modes can coexist with each other. The calculated TiIV coordination numbers, TiIVO bond elongations, and charge transfers caused by NH3 adsorption are in good agreement with previous results. Similarly, two different NH3 adsorption modes exist for the Ti3III site; the site that exhibits radical transfer from the lattice O to N atoms is preferred due to the higher adsorption energy. This indicates that the Ti3III site does not show Lewis acidity, in contrast to the Ti3IV site. At the Ti3III site, the energy barrier for activating the methane CH bond was calculated to be 33.3 kJ mol−1 and is greatly reduced by replacing the hydrogen atoms with methyl groups. In addition, the reactivity is improved when switching from MCM‐22 to TS‐1 zeolite. The studies on the various Ti species reveal that lattice O atoms rather than TiIII radicals are crucial to the activation of alkane CH bonds. This work provides new insights into and aids understanding of the catalysis by isolated Ti species in zeolites.
Heuristic Chemistry—Addition Reactions
Authors: Graulich Nicole , Hopf Henning , Schreiner Peter R.
Published: January 2011

Organic chemistry is often considered a difficult subject requiring great effort to achieve expert status. Only once this level has been reached, judging, deciding, and recalling chemical information will be fast and guided by heuristic strategies. These principles, used intuitively, improve the efficiency and speed of problem‐solving and decision‐making procedures. Establishing these strategies in teaching and learning chemistry should significantly help students acquire well‐structured procedural knowledge early in their education. In an attempt to improve conceptual thinking in teaching organic chemistry, in this contribution we develop a heuristic view of addition reactions and propose a new way of perceiving this class of organic reactions.
Development of Fluorescent Glucose Bioprobes and Their Application on Real‐Time and Quantitative Monitoring of Glucose Uptake in Living Cells
Authors: Lee Hyang Yeon , Lee Jae Jeong , Park Jongmin , Park Seung Bum
Published: January 2011

We developed a novel fluorescent glucose bioprobe, GB2‐Cy3, for the real‐time and quantitative monitoring of glucose uptake in living cells. We synthesized a series of fluorescent glucose analogues by adding Cy3 fluorophores to the α‐anomeric position of D‐glucose through various linkers. Systematic and quantitative analysis of these Cy3‐labeled glucose analogues revealed that GB2‐Cy3 was the ideal fluorescent glucose bioprobe. The cellular uptake of this probe competed with the cellular uptake of D‐glucose in the media and was mediated by a glucose‐specific transport system, and not by passive diffusion. Flow cytometry and fluorescence microscopy analyses revealed that GB2‐Cy3 is ten times more sensitive than 2‐NBDG, a leading fluorescent glucose bioprobe. GB2‐Cy3 can also be utilized for the quantitative flow cytometry monitoring of glucose uptake in metabolically active C2C12 myocytes under various treatment conditions. As opposed to a glucose uptake assay performed by using radioisotope‐labeled deoxy‐D‐glucose and a scintillation counter, GB2‐Cy3 allows the real‐time monitoring of glucose uptake in living cells under various experimental conditions by using fluorescence microscopy or confocal laser scanning microscopy (CLSM). Therefore, we believe that GB2‐Cy3 can be utilized in high‐content screening (HCS) for the discovery of novel therapeutic agents and for making significant advances in biomedical studies and diagnosis of various diseases, especially metabolic diseases.
Desilication Mechanism Revisited: Highly Mesoporous All‐Silica Zeolites Enabled Through Pore‐Directing Agents
Authors: Verboekend Danny , Pérez‐Ramírez Javier
Published: January 2011

The role of pore‐directing agents (PDAs) in the introduction of hierarchical porosity in silicalite‐1 in alkaline medium was investigated. By incorporation of various PDAs in aqueous NaOH, homogenously distributed mesopores were introduced in 2.5 μm silicalite‐1 crystals. It was proven for the first time that framework aluminum is not a prerequisite for the introduction of intracrystalline mesoporosity by desilication. The pore‐directing role is not directly exerted by framework trivalent cations metals, but by species on the external surface of the zeolite. The inclusion of metal complexes (Al(OH)4−, Ga(OH)4−) and tetraalkyl ammonium cations (tetramethyl ammonium (TMA+), tetrapropyl ammonium (TPA+)) in the alkaline solution led to distinct mesopore surface areas (up to 286 m2 g−1) and pore sizes centered in the range of 5–20 nm. In the case alkaline treatment was performed in the presence of Al(OH)4−, all aluminum partially integrated in the zeolite giving rise to both Lewis and Brønsted acidity. Apart from the concentration and location, the affinity of the PDA to the zeolite surface plays a crucial role in the pore formation process. If the PDA is attracted too strongly (e.g., TMA+), the dissolution is reduced dramatically. When the pore‐directing agent is not attracted to the zeolite’s external surface, excessive dissolution occurs (standard alkaline treatment). TPA+ proved to be the most effective PDA as its presence led to high mesopore surface areas (>200 m2 g−1) over a broad range of PDA concentrations (0.003–0.1 M). Importantly, our results enable to extend the suitability of desilication for controlled mesopore formation to all‐silica zeolites.
Enzyme‐Inspired Controlled Release of Cucurbit[7]uril Nanovalves by Using Magnetic Mesoporous Silica
Authors: Liu Jinshui , Du Xuezhong , Zhang Xianfeng
Published: January 2011

The controlled release of drugs by biostimuli is highly desirable under physiological conditions for their potential use in advanced applications. The enzyme‐inspired controlled release of cucurbituril nanovalves by using magnetic mesoporous silica nanoparticles (MSNs) in near‐neutral aqueous solutions is reported for the first time. The encirclement of cucurbit[7]uril (CB[7]) onto the protonated 1,4‐butanediamine stalks tethered to the external surfaces of superparamagnetic Fe3O4‐embedded mesoporous silica particles leads to tight blocking of the nanopores. The supramolecular nanovalves are activated by the enzymatic decarboxylation products of lysine, cadaverine (in the protonated form), which has a high affinity for CB[7], so that the encapsulated guest molecules, calcein, in the nanopores are released into the bulk solution. The release of calcein can be controlled in small portions on command by alternating changes in enzymatic decarboxylation products and CB[7]. The amino acid derived polyamines have long been associated with cell growth and cancers. The guest molecules released from the delivery system of magnetic MSNs can act not only on sensing probes for levels of decarboxylases and polyamines, but also on efficacious drugs to specific tissues and cells for regulation of polyamine synthesis.
Nickel‐Catalyzed, Cascade Cycloadditions of 1‐Ethynyl‐8‐halonaphthalenes with Nitriles: Synthesis, Structure, and Physical Properties of New Pyrroloarenes
Authors: Wu Tsun‐Cheng , Tai Chia‐Cheng , Tiao Hsin‐Chieh , Kuo Ming‐Yu , Wu Yao‐Ting
Published: January 2011

The reaction of 1‐ethynyl‐8‐halonaphthalenes 1 with nitriles in the presence of the catalytic system [NiBr2(dppe)]/Zn (dppe=1,2‐bis(diphenylphosphino)ethane) is found to produce unusual pyrroloarenes 2. The carbon–nitrogen triple bond in nitrile is activated twice, and five new bonds are formed in a one‐pot transformation, which causes a pyrrole and two six‐membered rings to be generated simultaneously. The scope and limitations of this reaction are examined. Similarly, alkyl‐bridged diynes also furnish the corresponding polycycles. Diaryl‐substituted cycloadducts 2 (R1=Ar) are fluxional, because of the restriction in rotation of the aryl groups. The rotational barrier is studied by performing 1H NMR experiments at various temperatures. The structures of several compounds are determined by X‐ray crystallographic analysis. The photophysical and electrochemical properties of the pyrroloarenes are also investigated.
Epibranchial placode‐derived neurons produce BDNF required for early sensory neuron development
Authors: Harlow Danielle E. , Yang Hui , Williams Trevor , Barlow Linda A.
Published: January 2011

In mice, BDNF provided by the developing taste epithelium is required for gustatory neuron survival following target innervation. However, we find that expression of BDNF, as detected by BDNF‐driven β‐galactosidase, begins in the cranial ganglia before its expression in the central (hindbrain) or peripheral (taste papillae) targets of these sensory neurons, and before gustatory ganglion cells innervate either target. To test early BDNF function, we examined the ganglia of bdnf null mice before target innervation, and found that while initial neuron survival is unaltered, early neuron development is disrupted. In addition, fate mapping analysis in mice demonstrates that murine cranial ganglia arise from two embryonic populations, i.e., epibranchial placodes and neural crest, as has been described for these ganglia in non‐mammalian vertebrates. Only placodal neurons produce BDNF, however, which indicates that prior to innervation, early ganglionic BDNF produced by placode‐derived cells promotes gustatory neuron development. Developmental Dynamics 240:309–323, 2011. © 2011 Wiley‐Liss, Inc.
Synthesis of a [3Fe2S] Cluster with Low Redox Potential from [2Fe2S] Hydrogenase Models: Electrochemical and Photochemical Generation of Hydrogen
Authors: Gao Weiming , Sun Junliang , Li Mingrun , Åkermark Torbjörn , Romare Kristina , Sun Licheng , Åkermark Björn
Published: January 2011

In the attempted replacement of carbon monoxide by thebis(phosphane) dppv in a dinuclear [2Fe2S] complex, a trinuclear [3Fe2S] complex with two bis(phosphane) ligands was unexpectedly obtained. On protonation, this gave a bridged hydride complex with an unusually low potential for the reduction of protons to molecular hydrogen. The redox potential also appears sufficiently positive for direct electron transfer from an excited [Ru(bpy)3]2+ sensitizer.
Growth and biomass production with enhanced β‐glucan and dietary fibre contents of Ganoderma australe ATHUM 4345 in a batch‐stirred tank bioreactor
Authors: Papaspyridi Lefki‐Maria , Katapodis Petros , Gonou‐Zagou Zacharoula , Kapsanaki‐Gotsi Evangelia , Christakopoulos Paul
Published: January 2011

In this study we maximized biomass production by the basidiomycete Ganoderma australe ATHUM 4345, a species of pharmaceutical interest as it is a valuable source of nutraceuticals, including dietary fibers and glucans. We used the Biolog FF MicroPlate to screen 95 different carbon sources for growth monitoring. The pattern of substrate catabolism forms a substrate assimilation fingerprint, which is useful in selecting components for media optimization of maximum biomass production. Response surface methodology, based on the central composite design was applied to explore the optimum concentrations of carbon and nitrogen sources of culture medium in shake flask cultures. When the improved culture medium was tested in a 20‐L stirred tank bioreactor, using 13.7 g/L glucose and 30.0 g/L yeast extract, high biomass yields (10.1±0.4 g/L) and productivity of 0.09 g L−1 h−1 were obtained. The yield coefficients for total glucan and dietary fibers on biomass formed were 94.82±6 and 341.15±12.3 mg/g mycelium dry weight, respectively.
Asset allocation in the Athens stock exchange: a variance sensitivity analysis
Authors: Diamandis Panayiotis F. , Drakos Anastassios A. , Kouretas Georgios P. , Zarangas Leonidas P.
Published: January 2011

This paper provides an analysis of asset allocation using univariate portfolio GARCH models applied on daily data for the period January 1999 to December 2009 on stocks traded in the Athens Stock Exchange, a recently monitored emerging market. Our analysis adopts the variance sensitivity analysis (VSA) methodology due to Manganelli (2004) and we are able to recover from the univariate approach the multivariate dimension of the portfolio allocation problem. The main results of the analysis are: First, we demonstrate that using a two asset portfolio consisting of blue chips traded in the Greek capital market the estimated variance is a parabolic and convex function of the estimated weights providing evidence that diversification produces significant gains in terms of risk reduction. Second, based on the shape of the first and second derivatives the model misspecification due to the fitting univariate GARCH models is insignificant. Third, we compare the performance of VSA against that of three popular multivariate GARCH models and it is shown that the adopted methodology provides more efficient results than the competing models. The gains in efficiency get larger as the size of the portfolio increases. Finally, with the application of the Kupiec's test for out‐of‐sample forecasting performance we demonstrate that the VSA outperforms all three alternative models at both the 95% and 99% confidence interval independently of the trading position. Copyright © 2011 John Wiley & Sons, Ltd.
A PANEL DATA APPROACH FOR PROGRAM EVALUATION: MEASURING THE BENEFITS OF POLITICAL AND ECONOMIC INTEGRATION OF HONG KONG WITH MAINLAND CHINA
Authors: Hsiao Cheng , Steve Ching H. , Ki Wan Shui
Published: January 2011

We propose a simple‐to‐implement panel data method to evaluate the impacts of social policy. The basic idea is to exploit the dependence among cross‐sectional units to construct the counterfactuals. The cross‐sectional correlations are attributed to the presence of some (unobserved) common factors. However, instead of trying to estimate the unobserved factors, we propose to use observed data. We use a panel of 24 countries to evaluate the impact of political and economic integration of Hong Kong with mainland China. We find that the political integration hardly had any impact on the growth of the Hong Kong economy. However, the economic integration has raised Hong Kong's annual real GDP by about 4%. Copyright © 2011 John Wiley & Sons, Ltd.
Lateral augmentation of the mandible in minipigs with a synthetic nanostructured hydroxyapatite block
Authors: Kirchhoff Mark , Lenz Solvig , Henkel Kai‐Olaf , Frerich Bernhard , Holzhüter Gerd , Radefeldt Sven , Gerber Thomas
Published: January 2011

The purpose of this study was to evaluate biomaterial degradation and new bone formation after implantation of a nanostructured hydroxyapatite (HA) grafting block. Furthermore, physical characteristics of the biomaterial were measured. The biomaterial consists of nanostructured HA embedded in a porous matrix of silica (SiO2) gel. The blocks with two different contents of silica (group A: 24 wt % and group B: 39 wt %) were fixed with titanium screws at the lateral aspect of the mandible of minipigs (n = 5). The specific surface areas of both blocks were measured using Brunauer–Emmett–Teller (BET) equation and mercury intrusion. In all animals, the wound healing was uneventful. After 5 weeks, the biomaterial percentage was 51.5% ± 12.1% for group A and 33.2% ± 5.9% for group B (p = 0.017). New bone formation accounted to 7.6% ± 6.0% for group A and 15.3% ± 8.3% for group B (p = 0.126) after 5 weeks. After 10 weeks, further resorption of the biomaterial led to percentages of 30.6% ± 10.0% for group A and 12.1% ± 6.7% for group B (p = 0.000). After 10 weeks, new bone formations were measured to be 34.1% ± 10.8% in group A and 39.9% ± 13.5% in group B (p = 0.383). The rate of degradation of the biomaterial is controlled by the composition of the material. A higher content of silica gel matrix leads to faster degradation of the biomaterial. The formation of new bone failed to show a significant difference between both groups. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Predicting employee engagement in an age‐diverse retail workforce
Authors: James Jacquelyn Boone , McKechnie Sharon , Swanberg Jennifer
Published: January 2011

The news that the early retirement trend has been reversed and current older workers plan to work past conventional retirement ages has been widely heralded. Managers have been encouraged to make adjustments to differences in job conditions that are important to older workers. We use social exchange theory and the norm of reciprocity as a framework for examining six dimensions of job quality for their impact on employee engagement among several groups of older and younger workers at different points in the cycle of their careers in a large retail setting. Employees (N = 6047) were surveyed as part of a large‐scale research project. Exploratory factor analyses identified commonalities among 27 job quality variables and four reliable factors. Regression analyses estimated the relationship between four job conditions and employee engagement. Although the relative weights of the factors differed by career stage, the same factors: (1) Supervisor Support and Recognition; (2) Schedule Satisfaction; and (3) Job Clarity were significant predictors of employee engagement for all age groups; (4) Career Development was a predictor for all but the retirement‐eligible employees. Findings reveal the importance of recognizing age diversity among both young and old employees. Both theoretical and practical implications are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Maintaining a focus on opportunities at work: The interplay between age, job complexity, and the use of selection, optimization, and compensation strategies
Authors: Zacher Hannes , Frese Michael
Published: January 2011

The concept of focus on opportunities describes how many new goals, options, and possibilities employees believe to have in their personal future at work. This study investigated the specific and shared effects of age, job complexity, and the use of successful aging strategies called selection, optimization, and compensation (SOC) in predicting focus on opportunities. Results of data collected from 133 employees of one company (mean age = 38 years, SD = 13, range 16–65 years) showed that age was negatively, and job complexity and use of SOC strategies were positively related to focus on opportunities. In addition, older employees in high‐complexity jobs and older employees in low‐complexity jobs with high use of SOC strategies were better able to maintain a focus on opportunities than older employees in low‐complexity jobs with low use of SOC strategies. Copyright © 2010 John Wiley & Sons, Ltd.
Influence of shriveling on berry composition and antioxidant activity of Cabernet Sauvignon grapes from Shanxi vineyards
Authors: Fang Yulin , Meng Jiangfei , Zhang Ang , Liu Jinchuan , Xu Tengfei , Yu Weilong , Chen Shuxia , Li Hua , Zhang Zhenwen , Wang Hua
Published: January 2011

BACKGROUND: Berry shrivel (BS), a berry development disorder, appears soon after veraison. It occurs worldwide and affects the quality of grape berries and wine. However, it had not been reported in China until recently. This study aimed to investigate the changes in berry composition and antioxidant activity of Cabernet Sauvignon grapes from Xiangning Valley, Shanxi Province, China, during BS.

RESULTS: Shrinkage contributed to an increase in the concentration of basic grape ingredients such as sugar and acid. An appropriate degree of shrinkage was apparently helpful in improving the phenolic content and increasing the antioxidant activity, but the berries that continued to shrivel showed a low antioxidant activity. Further, the results indicated distinct differences between the berries harvested from the southern side of the canopy and those harvested from the northern side, presumably due to variations in sunlight exposure.

CONCLUSION: Moderate BS was beneficial since it increased berry quality and antioxidant activity of Cabernet Sauvignon grapes from Shanxi vineyards. Copyright © 2011 Society of Chemical Industry
A minimal energy control problem for second‐order linear hyperbolic systems with two independent variables
Authors: Hasanov K. K. , Gasumov T. M.
Published: January 2011

In this paper, we investigate controllability and minimal energy optimal control for Goursat–Darboux problem for the second‐order linear hyperbolic systems with two independent variables. The equation describes a relation between functions u: D→ℝm and z: D→ℝn. We get an integral representation of the Goursat–Darboux problem by means of Riemann's matrix. The first half of the paper considers conditions under which there exists a control u for which the solution z of dynamics satisfies z(x1, y1) = p for any given p. The studied problem is reduced to the moments problem. The optimal control was found in a closed analytic form. Further, degeneracy of the matrix constructed by means of Riemann's matrix is shown to be a necessary and sufficient condition of controllability. Copyright © 2011 John Wiley & Sons, Ltd.
Unveiling the molecular pathogenesis of chordoma: a new paradigm for molecular targeting of rare cancers
Authors: Dei Tos Angelo Paolo
Published: January 2011

‘Chordoma’ represents orphan sarcoma subtypes in which systemic treatments have so far proved ineffective. Two original papers in the Journal of Pathology have recently elucidated important steps of its molecular oncogenesis. The demonstration of gains of copy number of both T (brachyury homologue) and EGFR (epidermal growth factor receptor) genes in chordoma, as well as of their role in promoting cell proliferation, offers a strong preclinical rationale for exploring the inhibition of their products as a credible therapeutic strategy. When dealing with rare cancers, clinical trials based on a frequency‐based statistical methodology are hardly feasible. To override the limitations of rarity, the clinical community is suggesting the adoption of a Bayesian methodology. The success of innovative clinical trials strongly depends upon the availability of preclinical evidences of efficacy. The papers discussed herein represent good examples of what is actually needed to set up a solid prior probability. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Subtype‐specific mutation of PPP2R1A in endometrial and ovarian carcinomas
Authors: McConechy Melissa K , Anglesio Michael S , Kalloger Steve E , Yang Winnie , Senz Janine , Chow Christine , Heravi‐Moussavi Alireza , Morin Gregg B , Mes‐Masson Anne‐Marie ,   Australian Ovarian Cancer Study Group, Carey Mark S , McAlpine Jessica N , Kwon Janice S , Prentice Leah M , Boyd Niki , Shah Sohrab P , Gilks C. Blake , Huntsman David G
Published: January 2011

PPP2R1A mutations have recently been described in 3/42 (7%) of clear cell carcinomas of the ovary. PPP2R1A encodes the α‐isoform of the scaffolding subunit of the serine/threonine protein phosphatase 2A (PP2A) holoenzyme. This putative tumour suppressor complex is involved in growth and survival pathways. Through targeted sequencing of PPP2R1A, we identified somatic missense mutations in 40.8% (20/49) of high‐grade serous endometrial tumours, and 5.0% (3/60) of endometrial endometrioid carcinomas. Mutations were also identified in ovarian tumours at lower frequencies: 12.2% (5/41) of endometrioid and 4.1% (2/49) of clear cell carcinomas. No mutations were found in 50 high‐grade and 12 low‐grade serous carcinomas. Amino acid residues affected by these mutations are highly conserved across species and are involved in direct interactions with regulatory B‐subunits of the PP2A holoenzyme. PPP2R1A mutations in endometrial high‐grade serous carcinomas are a frequent and potentially targetable feature of this disease. The finding of frequent PPP2R1A mutations in high‐grade serous carcinoma of the endometrium but not in high‐grade serous carcinoma of the ovary provides clear genetic evidence that these are distinct diseases. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Conditional β1‐integrin‐deficient mice display impaired pancreatic β cell function
Authors: Riopel M. , Krishnamurthy M. , Li J. , Liu S. , Leask A. , Wang R.
Published: January 2011

β1‐Integrin, a critical regulator of β cell survival and function, has been shown to protect against cell death and promote insulin expression and secretion in rat and human islet cells in vitro. The aim of the present study was to examine whether the knockout of β1‐integrin in collagen I‐producing cells would have physiological and functional implications in pancreatic endocrine cells in vivo. Using adult mice with a conditional knockout of β1‐integrin in collagen I‐producing cells, the effects of β1‐integrin deficiency on glucose metabolism and pancreatic endocrine cells were examined. Male β1‐integrin‐deficient mice display impaired glucose tolerance, with a significant reduction in pancreatic insulin content (p < 0.01). Morphometric analysis revealed a significant reduction in β cell mass (p < 0.001) in β1‐integrin‐deficient mice, along with a significant decrease in β cell proliferation, Pdx‐1 and Nkx6.1 expression when compared with controls. Interestingly, these physiological and morphometric alterations in female β1‐integrin‐deficient mice were less significant. Furthermore, β1‐integrin‐deficient mice displayed decreased FAK (p < 0.05) and ERK1/2 (p < 0.001) phosphorylation, reduced cyclin D1 levels (p < 0.001) and increased caspase 3 cleavage (p < 0.01), while no changes in Akt phosphorylation were observed, indicating that the β1‐integrin signals through the FAK–MAPK–ERK pathway in vivo. Our results demonstrate that β1‐integrin is involved in the regulation of glucose metabolism and contributes to the maintenance of β cell survival and function in vivo. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Prominent expression of sialyl Lewis X‐capped core 2‐branched O‐glycans on high endothelial venule‐like vessels in gastric MALT lymphoma
Authors: Kobayashi Motohiro , Mitoma Junya , Hoshino Hitomi , Yu Shin‐Yi , Shimojo Yasuyo , Suzawa Kenichi , Khoo Kay‐Hooi , Fukuda Minoru , Nakayama Jun
Published: January 2011

High endothelial venule (HEV)‐like vessels have been observed in gastric B cell lymphoma of mucosa‐associated lymphoid tissue type (MALT lymphoma), as well as in its preceding lesion, chronic Helicobacter pylori gastritis. Previously we reported that glycans on HEV‐like vessels in the latter lesion served as L‐selectin ligands, although their function is unclear. We have investigated sialyl Lewis X (sLeX)‐related glycoepitopes and found that MECA‐79−/HECA‐452+/NCC‐ST‐439+ HEV‐like vessels preferentially mark gastric MALT lymphoma compared to chronic H. pylori gastritis. We then constructed CHO cell lines expressing potential MECA‐79−/HECA‐452+/NCC‐ST‐439+ glycans, as well as other sLeX‐type glycans, on CD34 and evaluated L‐selectin binding to those cells, using L‐selectin–IgM chimera binding and lymphocyte adhesion assays. L‐selectin–IgM chimeras bound to CHO cells expressing 6‐sulpho‐sLeX attached to core 2‐branched O‐glycans with or without 6‐sulpho‐sLeX attached to extended core 1 O‐glycans, but only marginally to other CHO cell lines. By contrast, CHO cells expressing 6‐sulpho‐sLeX attached to extended core 1 and/or core 2‐branched O‐glycans, as well as non‐sulphated sLeX attached to core 2‐branched O‐glycans, showed substantial lymphocyte binding, while binding was negligible on lines expressing 6‐sulpho‐ and non‐sulphated sLeX attached to N‐glycans and non‐sulphated sLeX attached to extended core 1 O‐glycans. These results indicate that MECA‐79−/HECA‐452+/NCC‐ST‐439+ glycans, specifically, 6‐sulpho‐ and non‐sulphated sLeXs attached to core 2‐branched O‐glycans, expressed on HEV‐like vessels in gastric MALT lymphoma function as L‐selectin ligands and likely contribute to H. pylori‐specific T cell recruitment in the progression of gastric MALT lymphoma. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Hepatic artery Doppler in trisomy 21 and euploid fetuses at 11–13 weeks
Authors: Zvanca Mona , Gielchinsky Yuval , Abdeljawad Firas , Bilardo Caterina M. , Nicolaides Kypros H.
Published: January 2011

Objective

To determine possible differences in hepatic artery flow between trisomy 21 and euploid fetuses at 11–13 weeks' gestation.

Methods

Hepatic artery pulsatility index (PI) and peak systolic velocity (PSV) were measured in fetuses at low risk of aneuploidies (n = 350) and another group at high risk, including 283 euploid and 47 with trisomy 21. The association of hepatic artery PI and PSV with trisomy 21, fetal nuchal translucency (NT) thickness, tricuspid regurgitation, and reversed a‐wave in the ductus venosus was investigated.

Results

In the low‐risk group, the median hepatic artery PSV was 10.0 cm/s and the 95th centile was 14.3 cm/s. The distribution of hepatic artery PI was skewed, but for PI of 2 or more the distribution was Gaussian. In 325 (92.9%) cases, the PI was 2 or more (high PI) and in 25 (7.1%) it was below 2 (low PI). In 33 (70.2%) of the trisomy 21 pregnancies, the PSV was above the 95th centile and the PI was below 2. Multiple regression analysis showed that in the prediction of hepatic artery PSV there were significant contributions from fetal karyotype, tricuspid regurgitation, and reversed a‐wave in the ductus venosus, but not delta NT, pregnancy‐associated plasma protein‐A, or free β‐human chorionic gonadotrophin.

Conclusion

Trisomy 21 at 11–13 weeks is associated with increased flow in the hepatic artery. Copyright © 2011 John Wiley & Sons, Ltd.
Early prenatal diagnosis of skeletal anomalies
Authors: Khalil Asma , Pajkrt Eva , Chitty Lyn S.
Published: January 2011

Objective

To review experience of early prenatal diagnosis of skeletal dysplasias, and to explore diagnostic accuracy and improve management.

Methods

A retrospective review of fetal medicine unit (FMU) records was performed to identify cases where a skeletal dysplasia was suspected by 14 weeks' gestation. A literature review was undertaken to ascertain cases with a diagnosis of a skeletal dysplasia in the late first or early second trimester.

Results

Fifteen cases were identified from review of FMU records, including ten different dysplasias with a variety of inheritance patterns. Accurate prenatal diagnosis was made only in cases with a positive family history, and in one case each of thanatophoric dysplasia and Roberts syndrome. Review of the literature identified further cases. Increased nuchal translucency was reported in other cases subsequently diagnosed as having a skeletal dysplasia. In early pregnancy, common presenting features included short femora, abnormal skull shape and mineralisation, profile or chest.

Conclusion

Increasing use of first‐trimester combined screening for Down's syndrome, with or without detailed anomaly scanning, will result in early detection of more skeletal dysplasias. Parents must be made aware that detailed postnatal pathological and radiological examination is usually required for accurate diagnosis and prediction of recurrence risks. Copyright © 2011 John Wiley & Sons, Ltd.
First‐trimester screening: dealing with the fall‐out
Authors: Fisher Jane
Published: January 2011

The articles collected together in this issue describe first‐trimester screening for a variety of complications. With the advance of both technology and research, early pregnancy screening is becoming ever more sophisticated and complex. While there are clear benefits to most women receiving early reassurance that their baby is developing as expected, there is no evidence to suggest that an earlier prenatal diagnosis has less long‐term emotional impact than at later gestations. The poignancy of ultrasound images for many parents means that it can be especially difficult to manage the anxiety when an ultrasound marker is highlighted as potential cause for concern. They can then face a journey of anxiety‐laden uncertainty, which can extend through much of the pregnancy, and even beyond. Professionals involved in screening need to recognise and acknowledge such adverse side‐effects and develop the skills necessary to help parents understand and cope with the uncertainties inherent in the process. Copyright © 2011 John Wiley & Sons, Ltd.
From irradiance to output power fluctuations: the PV plant as a low pass filter
Authors: Marcos Javier , Marroyo Luis , Lorenzo Eduardo , Alvira David , Izco Eloisa
Published: January 2011

The power generated by large grid‐connected photovoltaic (PV) plants depends greatly on the solar irradiance. This paper studies the effects of the solar irradiance variability analyzing experimental 1‐s data collected throughout a year at six PV plants, totaling 18 MWp. Each PV plant was modeled as a first order filter function based on an analysis in the frequency domain of the irradiance data and the output power signals. An empiric expression which relates the filter parameters and the PV plant size has been proposed. This simple model has been successfully validated precisely determining the daily maximum output power fluctuation from incident irradiance measurements. Copyright © 2011 John Wiley & Sons, Ltd.
High efficiency low temperature grown Cu(In,Ga)Se2 thin film solar cells on flexible substrates using NaF precursor layers
Authors: Caballero Raquel , Kaufmann Christian A. , Eisenbarth Tobias , Unold Thomas , Klenk Reiner , Schock Hans‐Werner
Published: January 2011

We report a total‐area efficiency of 15.9% for flexible Cu(In,Ga)Se2 thin film solar cells on polyimide foil (cell area 0.95 cm2). The absorber layer was grown by a multi‐stage deposition process at a maximum nominal process temperature of 420°C. The Na was added via evaporation of a NaF layer prior to the absorber deposition leading to an enhanced Voc and FF. Growth conditions and device characterization are described. Copyright © 2011 John Wiley & Sons, Ltd.