bluuebunny/crossref_metadata_2025 huggingface dataset:
Occurrence of an invasive coral in the southwest Atlantic and comparison with a congener suggest potential niche expansion
Authors: Carlos‐Júnior Lélis A. , Neves Danilo M. , Barbosa Newton P. U. , Moulton Timothy P. , Creed Joel C.
Published: May 2015

Tubastraea tagusensis, a coral native to the Galapagos Archipelago, has successfully established and invaded the Brazilian coast where it modifies native tropical rocky shore and coral reef communities. In order to understand the processes underlying the establishment of T. tagusensis, we tested whether Maxent, a tool for species distribution modeling, based on the native range of T. tagusensis correctly forecasted the invasion range of this species in Brazil. The Maxent algorithm was unable to predict the Brazilian coast as a suitable environment for the establishment of T. tagusensis. A comparison between these models and a principal component analysis (PCA) allowed us to examine the environmental dissimilarity between the two occupied regions (native and invaded) and to assess the species' occupied niche breadth. According to the PCA results, lower levels of chlorophyll‐a and nitrate on the Atlantic coast segregate the Brazilian and Galapagos environments, implying that T. tagusensis may have expanded its realized niche during the invasion process. We tested the possible realized niche expansion in T. tagusensis by assuming that Tubastraea spp. have similar fundamental niches, which was supported by exploring the environmental space of T. coccinea, a tropical‐cosmopolitan congener of T. tagusensis. We believe that the usage of Maxent should be treated with caution, especially when applied to biological invasion (or climate change) scenarios where the target species has a highly localized native (original) distribution, which may represent only a small portion of its fundamental niche, and therefore a violation of a SDM assumption.
Breaking down a barrier: increasing perceived out‐group knowledge reduces negative expectancies about intergroup interaction
Authors: Aydogan Adem F. , Gonsalkorale Karen
Published: May 2015

Although intergroup contact is an effective way of reducing prejudice, negative expectancies about interacting with out‐group members often create a barrier to intergroup contact. The current study investigated cognitive appraisals by which negative expectancies may arise. Specifically, we examined whether increasing Anglo Australians' appraisals of their knowledge about Muslims would reduce their negative expectancies about an (ostensible) upcoming interaction with a Muslim Australian. Participants (89 Anglo Australians) completed a test that provided positive feedback either on their knowledge about Muslims or on their general knowledge (control). As predicted, Anglo Australians who received positive feedback on their knowledge about Muslims had a lower threat appraisal and expected to feel less anxious during the intergroup interaction compared with those who were in the control condition. This provides support for the precursory role out‐group knowledge may have as a resource that is appraised upon the prospect of an intergroup interaction.
A Facile Strategy to PdCu Bimetallic Alloy Nanosponges with Highly Porous Features as a High‐Performance Electrocatalytic Activity for Ethanol Electrooxidation in an Alkaline Medium
Authors: Zhai Yanling , Zhu Zhijun , Hong Wei , Dong Shaojun
Published: May 2015

Well‐defined three‐dimensional (3D) PdCu bimetallic alloy nanosponges (BANs) with highly porous structure was reported through a rapid and general strategy. Significantly, the as‐prepared PdCu BANs exhibited greatly enhanced activity and stability than commercial Pd/C catalyst towards ethanol electrooxidation in an alkaline medium. Pd1Cu1 shows higher active area and better electrocatalytic activity than Pd1Cu2 and Pd2Cu1. This result demonstrates the potential of applying these PdCu BANs as effective electrocatalysts for direct alcohol fuel cells (DAFCs).
Electrochemical Deposition and Spectroelectrochemical Response of Bromophenol Blue Films on Gold
Authors: Saydjari A. , Pietron J. J. , Simpkins B. S.
Published: May 2015

Bromophenol blue (BPB) was electropolymerized onto a Au substrate. The effects of voltammetric cycle number, BPB concentration, and pH on film thickness, density, optical absorption, and electrochemical susceptibility were evaluated, and favorable deposition conditions were identified. Quantitative measurement of the film mass via quartz crystal microbalance enabled determination of the molar volume and revealed a strong dependence of film density with deposition pH. Finally, electrochemical control of the optical properties of BPB films was demonstrated via in situ spectroelectrochemistry. We believe this is the first demonstration of electropolymerization of pure BPB on Au, and thus the first demonstration of poly(BPB) as an electrochemically switchable optical coating.
Biotic ligand modeling approach: Synthesis of the effect of major cations on the toxicity of metals to soil and aquatic organisms
Authors: Ardestani Masoud M. , van Straalen Nico M. , van Gestel Cornelis A. M.
Published: May 2015

The biotic ligand model (BLM) approach is used to assess metal toxicity, taking into account the competition of other cations with the free metal ions for binding to the biotic ligand sites of aquatic and soil organisms. The bioavailable fraction of metals, represented by the free metal ion, is a better measure than the total concentration for assessing their potential risk to the environment. Because BLMs are relating toxicity to the fraction of biotic ligands occupied by the metal, they can be useful for investigating factors affecting metal bioaccumulation and toxicity. In the present review, the effects of major cations on the toxicity of metals to soil and aquatic organisms were comprehensively studied by performing a meta-analysis of BLM literature data. Interactions at the binding sites were shown to be species- and metal-specific. The main factors affecting the relationships between toxicity and conditional binding constants for metal binding at the biotic ligand appeared to be Ca2+, Mg2+, and protons. Other important characteristics of the exposure medium, such as levels of dissolved organic carbon and concentrations of other cations, should also be considered to obtain a proper assessment of metal toxicity to soil and aquatic organisms. Environ Toxicol Chem 2015;34:2194–2204. © 2015 SETAC
The metabolomics of asthma control: a promising link between genetics and disease
Authors: McGeachie Michael J. , Dahlin Amber , Qiu Weiliang , Croteau‐Chonka Damien C. , Savage Jessica , Wu Ann Chen , Wan Emily S. , Sordillo Joanne E. , Al‐Garawi Amal , Martinez Fernando D. , Strunk Robert C. , Lemanske Robert F. , Liu Andrew H. , Raby Benjamin A. , Weiss Scott , Clish Clary B. , Lasky‐Su Jessica A.
Published: May 2015

Short‐acting β agonists (e.g., albuterol) are the most commonly used medications for asthma, a disease that affects over 300 million people in the world. Metabolomic profiling of asthmatics taking β agonists presents a new and promising resource for identifying the molecular determinants of asthma control. The objective is to identify novel genetic and biochemical predictors of asthma control using an integrative “omics” approach. We generated lipidomic data by liquid chromatography tandem mass spectrometry (LC‐MS), ­ using plasma samples from 20 individuals with asthma. The outcome of interest was a binary indicator of asthma control defined by the use of albuterol inhalers in the preceding week. We integrated metabolomic data with genome‐wide genotype, gene expression, and methylation data of this cohort to identify genomic and molecular indicators of asthma control. A Conditional Gaussian Bayesian Network (CGBN) was generated using the strongest predictors from each of these analyses. Integrative and metabolic pathway over‐representation analyses (ORA) identified enrichment of known biological pathways within the strongest molecular determinants. Of the 64 metabolites measured, 32 had known identities. The CGBN model based on four SNPs (rs9522789, rs7147228, rs2701423, rs759582) and two metabolites—monoHETE_0863 and sphingosine‐1‐phosphate (S1P) could predict asthma control with an AUC of 95%. Integrative ORA identified 17 significantly enriched pathways related to cellular immune response, interferon signaling, and cytokine‐related signaling, for which arachidonic acid, PGE2 and S1P, in addition to six genes (CHN1, PRKCE, GNA12, OASL, OAS1, and IFIT3) appeared to drive the pathway results. Of these predictors, S1P, GNA12, and PRKCE were enriched in the results from integrative and metabolic ORAs. Through an integrative analysis of metabolomic, genomic, and methylation data from a small cohort of asthmatics, we implicate altered metabolic pathways, related to sphingolipid metabolism, in asthma control. These results provide insight into the pathophysiology of asthma control.
Overexpression of SIX1 is an independent prognostic marker in stage I–III colorectal cancer
Authors: Kahlert Christoph , Lerbs Tristan , Pecqueux Mathieu , Herpel Esther , Hoffmeister Michael , Jansen Lina , Brenner Hermann , Chang‐Claude Jenny , Bläker Hendrik , Kloor Matthias , Roth Wilfried , Pilarsky Christian , Rahbari Nuh N. , Schölch Sebastian , Bork Ulrich , Reissfelder Christoph , Weitz Jürgen , Aust Daniela , Koch Moritz
Published: May 2015

Epithelial‐to‐mesenchymal transition (EMT) contributes significantly to tumor progression and metastasis. The assessment of EMT‐associated transcription factors could be a promising approach to identify biomarkers and potential therapeutic targets in colorectal cancer. In our study, we focused on the transcription factor “Sine oculis homeobox” (SIX) 1, which is a member of the superfamily of the homeobox genes and has been described to promote EMT in different types of tumors. Immunohistochemistry against SIX1 was performed on colorectal mucosa, adenomas, carcinomas‐in situ and primary adenocarcinomas. An expression score was developed and subsequently assessed for its prognostic value in two independent cohorts. Cohort 1 consisted of 128 patients with stage I–III colorectal cancer; cohort 2 included 817 patients with stage I–III colorectal cancer who had participated in the DACHS study. HCT‐116 cells were transfected with SIX1 plasmids and subjected to migration and colony formation assays. The expression of SIX1 increases gradually from mucosa to colorectal adenocarcinomas (p > 0.0001). Univariate and multivariate analyses reveal that high expression of SIX1 is associated with decreased overall survival (cohort 1: HR: 4.01, CI: 1.20–14.07, p = 0.025; cohort 2: HR: 1.43, CI: 1.014–2.02, p = 0.047). Overexpression of SIX1 induces a more mesenchymal‐like phenotype in HCT‐116 cells and enhances tumor migration. High expression of SIX1 is an independent prognostic marker in colorectal cancer. It might be a promising biomarker to stratify patients into different risk groups. Moreover, targeting SIX1 might be a novel therapeutic approach in patients with colorectal cancer.
Expression of Concern: Selective depletion of tumor neovasculature by microbubble destruction with appropriate ultrasound pressure
Authors: Wang Junfen , Zhao Zonglei , Shen Shuxin , Zhang Chuanxi , Guo Shengcun , Lu Yongkang , Chen Yanmei , Liao Wangjun , Liao Yulin , Bin Jianping
Published: May 2015

Low‐intensity ultrasound‐microbubble (LIUS‐MB) treatment is a promising antivascular therapy for tumors. We sought to determine whether LIUS‐MB treatment with an appropriate ultrasound pressure could achieve substantial and persistent cessation of tumor perfusion without having significant effects on normal tissue. Further, we investigated the mechanisms underlying this treatment. Murine S‐180 sarcomas, thigh muscles, and skin tissue from 60 tumor‐bearing mice were subjected to sham therapy, an ultrasound application combined with microbubbles in four different ultrasound pressures (0.5, 1.5, 3.0, 5.0 MPa), or ultrasound at 5.0 MPa alone. Subsequently, contrast‐enhanced ultrasonic imaging and histological studies were performed. Tumor microvessels, tumor cell necrosis, apoptosis, tumor growth, and survival were evaluated in 85 mice after treatment with the selected ultrasound pressure. We found that twenty‐four hours after LIUS‐MB treatment at 3.0 MPa, blood perfusion and microvessel density of the tumor had substantially decreased by 84 ± 8% and 84%, respectively (p < 0.01). Similar reductions were not observed in the muscle or skin. Additionally, an extreme reduction in the number of immature vessels was observed in the tumor (reduced by 90%, p < 0.01), while the decrease in mature vessels was not significant. Further, LIUS‐MB treatment at 3.0 MPa promoted tumor cell necrosis and apoptosis, delayed tumor growth, and increased the survival rate of tumor‐bearing mice (p < 0.01). These findings indicate that LIUS‐MB treatment with an appropriate ultrasound pressure could selectively and persistently reduce tumor perfusion by depleting the neovasculature. Therefore, LIUS‐MB treatment offers great promise for clinical applications in antivascular therapy for solid tumors.
Force field‐dependent solution properties of glycine oligomers
Authors: Drake Justin A. , Pettitt B. Montgomery
Published: May 2015

Molecular simulations can be used to study disordered polypeptide systems and to generate hypotheses on the underlying structural and thermodynamic mechanisms that govern their function. As the number of disordered protein systems investigated with simulations increase, it is important to understand how particular force fields affect the structural properties of disordered polypeptides in solution. To this end, we performed a comparative structural analysis of Gly3 and Gly10 in aqueous solution from all atom, microsecond molecular dynamics (MD) simulations using the CHARMM 27 (C27), CHARMM 36 (C36), and Amber ff12SB force fields. For each force field, Gly3 and Gly10 were simulated for at least 300 ns and 1 μs, respectively. Simulating oligoglycines of two different lengths allows us to evaluate how force field effects depend on polypeptide length. Using a variety of structural metrics (e.g., end‐to‐end distance, radius of gyration, dihedral angle distributions), we characterize the distribution of oligoglycine conformers for each force field and show that each sample conformation space differently, yielding considerably different structural tendencies of the same oligoglycine model in solution. Notably, we find that C36 samples more extended oligoglycine structures than both C27 and ff12SB. © 2015 Wiley Periodicals, Inc.
A review of the role of robotics in bariatric surgery
Authors: Alibhai Mustafa H. , Shah Shinil K. , Walker Peter A. , Wilson Erik B.
Published: May 2015

The epidemic of obesity continues to be a major health issue. It is now almost uniform that surgical procedures for weight loss are performed with minimally invasive techniques. This article reviews the literature regarding obesity‐related health issues, in particular risk of malignancy, and the application of robotic technology in weight loss surgical procedures. With increasing literature and technology in surgical robotics, its application in the field of bariatric surgery continues to evolve. J. Surg. Oncol. 2015; 112:279–283. © 2015 Wiley Periodicals, Inc.
CD44 and CXCL9 serum protein levels predict the risk of clinically significant allograft rejection after liver transplantation
Authors: Raschzok Nathanael , Reutzel‐Selke Anja , Schmuck Rosa Bianca , Morgul Mehmet Haluk , Gauger Ulrich , Prabowo Kukuh Aji , Tannus Laura‐Marie , Leder Annekatrin , Struecker Benjamin , Boas‐Knoop Sabine , Bartels Michael , Jonas Sven , Lojewski Christian , Puhl Gero , Seehofer Daniel , Bahra Marcus , Pascher Andreas , Pratschke Johann , Sauer Igor Maximilian
Published: May 2015

The diagnosis of acute cellular rejection (ACR) after liver transplantation is based on histological analysis of biopsies because noninvasive biomarkers for allograft rejection are not yet established for clinical routines. CD31, CD44, and chemokine (C‐X‐C motif) ligand (CXCL) 9 have previously been described as biomarkers for cross‐organ allograft rejection. Here, we assessed the predictive and diagnostic value of these proteins as serum biomarkers for clinically significant ACR in the first 6 months after liver transplantation in a prospective study. The protein levels were measured in 94 patients immediately before transplantation, at postoperative days (PODs) 1, 3, 7, and 14 and when biopsies were performed during episodes of biochemical graft dysfunction. The CD44 serum protein levels were significantly lower at POD 1 in patients who experienced histologically proven ACR in the follow‐up compared with patients without ACR (P < 0.001). CXCL9 was significantly higher before transplantation (P = 0.049) and at POD 1 (P < 0.001) in these patients. Low CD44 values (cutoff, <200.5 ng/mL) or high CXCL9 values (cutoff, >2.7 ng/mL) at POD 1 differentiated between rejection and no rejection with a sensitivity of 88% or 60% and a specificity of 61% or 79%, respectively. The combination of both biomarker cutoffs at POD 1 had a positive predictive value of 91% and a negative predictive value of 67% for clinically significant ACR. Moreover, CD44 was significantly lower at the time of ACR (P < 0.001) and differentiated the rejection group from patients with graft dysfunction due to other reasons. Our results suggest that CD44 and CXCL9 may serve as predictive biomarkers to identify liver allograft recipients at risk for clinically significant ACR. Liver Transpl 21:1195–1207, 2015. © 2015 AASLD.
Is It Really Love? A Comparative Investigation of the Emotional Nature of Brand and Interpersonal Love
Authors: Langner Tobias , Schmidt Jennifer , Fischer Alexander
Published: May 2015

The use of interpersonal love theories is standard in brand love research. Yet no empirical evidence exists to confirm the equivalence of the emotional nature of these forms of love, which is required to justify the transfer of theories and measures from interpersonal to brand love settings. Building on dimensional emotional theories, this study compared the emotional nature of brand love against interpersonal love, interpersonal liking, and brand liking, using a mixed‐method approach. Qualitative Study 1 revealed emotional differences and similarities between the two love constructs; in particular, unlike interpersonal love, brand love was driven by rational benefits, such as product quality. Study 2 combined physiological and pictographic measures to show that brand love was less arousing than interpersonal love, though loved brands can be as arousing as close friends and induce more positive valence than this interpersonal relationship. According to dimensional emotional theories, interpersonal love and brand love thus differ, and researchers require prudence before transferring interpersonal love theories and scales directly to brand love research, without accounting for differences in the emotional nature of brand love and interpersonal love.
Drivers and Outcomes of Green Tourist Attitudes and Behavior: Sociodemographic Moderating Effects
Authors: Leonidou Leonidas C. , Coudounaris Dafnis N. , Kvasova Olga , Christodoulides Paul
Published: May 2015

This article reports the findings of a study, conducted among 234 foreign tourists who visited Cyprus, that aimed to identify the drivers and outcomes of eco‐friendly attitudes and behavior. Using structural equation modeling, the authors confirmed that deontological status, law obedience, and political action of tourists positively influence the adoption of an environmentally friendly attitude. In turn, these effects are conducive to eco‐friendly behavior, which ultimately enhances tourist satisfaction. Certain sociodemographic characteristics of tourists—namely, gender, age, education, and income—had a moderating effect on the link between deontological status, law obedience, and political action on the one hand and eco‐friendly attitudes on the other hand. Tourist nationality also had a control effect on tourist eco‐friendly attitudes.
Effect Symmetry of Benefit Criteria in Postpurchase Evaluations
Authors: Lee Dong‐Jin , Yu Grace B. , Merunka Dwight R. , Bosnjak Michael , Sirgy M. Joseph , Johar J. S.
Published: May 2015

This research proposes a theoretical model of postpurchase evaluations that incorporates seven sets of benefits: functional, symbolic, economic, safety, hedonic, moral, and leisure benefits. These benefit criteria are well documented in the literature. The study reported here was designed to test the effect symmetry of these benefit criteria in postpurchase evaluations. Effect symmetry refers to whether increases in a benefit are likely to cause proportional increases in postpurchase evaluations. The study tested the hypothesis that “must‐have” benefits (functional, economic, and safety benefits) are negatively asymmetric, whereas the “nice‐to‐have” benefits (symbolic, hedonic, moral, and leisure benefits) are positively symmetric. Five surveys were conducted in relation to five product categories in four countries (computers and automobiles in the United States, banks in France, housing in Korea, and leisure travel in Germany). Respondents completed 2386 questionnaires, of which 2291 were used in the statistical analysis. With respect to effect symmetry, the results indicate that the criterion of functional benefits is negatively asymmetric in predicting postpurchase evaluations, whereas symbolic and moral benefits are positively asymmetric. Hedonic and leisure benefits are symmetric. Managerial implications are discussed.
Disclosure of research results in genetic studies of Parkinson's disease caused byLRRK2mutations
Authors: Pont‐Sunyer Claustre , Bressman Susan , Raymond Deborah , Glickman Amanda , Tolosa Eduardo , Saunders‐Pullman Rachel
Published: May 2015

With the advent of large genetic studies examining both symptomatic and asymptomatic individuals, whether and how to disclose genetic research results have become pressing questions. The need is particularly acute in the case ofLRRK2research: Movement centers worldwide are recruiting cohorts of individuals with Parkinson's disease (PD) and their family members, including asymptomatic carriers. Clinical features and treatment are complex and evolving, and disclosure policies vary at different sites and have been modified during the course of some studies. We present the major ethical principles of autonomy, beneficence, nonmaleficence, and honesty that should guide disclosure policies in studies of families withLRRK2mutations. We make recommendations regarding genetic counseling, policies of either active or passive disclosure, responsibilities of funders to budget for genetic counseling, clinical genetic testing where locally required for disclosure, and aspects of study design to avoid mandatory disclosure whenever feasible. © 2015 International Parkinson and Movement Disorder Society
Virtually Designed Triclosan‐Based Inhibitors of Enoyl‐Acyl Carrier Protein Reductase of Mycobacterium tuberculosis and of Plasmodium falciparum
Authors: Owono Owono Luc C. , Ntie‐Kang Fidele , Keita Melalie , Megnassan Eugene , Frecer Vladimir , Miertus Stanislav
Published: May 2015

We report here new chemical structures of predicted nanomolar triclosan‐based inhibitors (TCLs) of Mycobacterium tuberculosis enoyl‐acyl carrier protein reductase (InhA) virtually proposed by computer‐assisted molecular design. 3D models of InhA‐TCL complexes were prepared by in situ modifications of the reference crystal structure (PDB entry 1P45) for a training set of 15 TCLs with known InhA inhibitory activities. A QSAR model was built leading to linear correlation between the calculated free energies of complexation (ΔΔGcom) and experimental values IC50exp: pIC50=−0.0657×ΔΔGcom+3.0502, R2=0.96. In addition, ligand‐based quantitative pharmacophore model (PH4) was built from bound conformations of the training set compounds and confirmed the correlation between molecular models and observed activities: pIC50exp=0.8929×pIC50pre−0.441, R2=0.95. Structural information from both models helped us to propose new TCL analogues. A virtual library of TCLs with known predicted activities against enoyl‐acyl carrier protein reductase of Plasmodium falciparum (PfENR) was evaluated, revealing dual target TCLs. Moreover, analysis of binding site interactions suggested enriching substitutions, which led to more potent TCLs with predicted pIC50pre as low as 7 nM. The computational approach, which used both free energy estimated from molecular modeling and 3D‐QSAR pharmacophore model, was helpful in virtually proposing the dual‐targeted drugs and provided valuable information for the design of novel potential antituberculotic agents.
Fast iterative pre‐emphasis calibration method enabling third‐order dynamic shim updated fMRI
Authors: Fillmer Ariane , Vannesjo Signe Johanna , Pavan Matteo , Scheidegger Milan , Pruessmann Klaas Paul , Henning Anke
Published: May 2015

Purpose

To calibrate a pre‐emphasis to sufficiently compensate eddy currents for application of dynamic shim updating to fMRI without extension of scan times.

Methods

Eddy current effects induced into all shim terms up to third‐order were characterized by spatiotemporal field monitoring, using a third‐order field camera. Pre‐emphasis settings were derived from the measurements and iteratively evaluated and refined. The calibrated pre‐emphasis was applied to slice‐wise dynamic shim updating in combination with a dynamic excitation frequency (F0) determination and a slice‐wise B0 optimization routine for in vivo echo planar imaging and resting‐state functional MRI.

Results

The described method for pre‐emphasis calibration led to settling times of remaining eddy current effects below 2 ms, allowing for the application of dynamic shim updating to fMRI without extension of scan times or induction of eddy current related artifacts. A dynamic F0 determination compensates frequency shifts induced by the superposition of different shim fields, and therefore, prevents an image shift within the field of view. Hardware limitations necessitate the reduction of the maximum applicable B0 shim field amplitudes and restrict the shim performance.

Conclusion

The proposed method enables accurate pre‐emphasis calibration, and therefore, the application of dynamic shim updating to fMRI. Magn Reson Med 75:1119–1131, 2016. © 2015 Wiley Periodicals, Inc.
An improved moving‐least‐squares reconstruction for immersed boundary method
Authors: Li Dong , Wei Anyang , Luo Kun , Fan Jianren
Published: May 2015

The current work presents an improved immersed boundary method based on the ideas proposed by Vanella and Balaras (M. Vanella, E. Balaras, A moving‐least‐squares reconstruction for embedded‐boundary formulations, J. Comput. Phys. 228 (2009) 6617–6628). In the method, an improved moving‐least‐squares approximation is employed to build the transfer functions between the Lagrangian points and discrete Eulerian grid points. The main advantage of the improved method is that there is no need to obtain the inverse matrix, which effectively eliminates numerical instabilities caused by matrix inversion and reduces the computational cost significantly. Several different flow problems (Taylor‐Green decaying vortices, flows past a stationary circular cylinder and a sphere, and the sedimentation of a free‐falling sphere in viscous fluid) are simulated to validate the accuracy and efficiency of the method proposed in the present paper. The simulation results show good agreement with previous numerical and experimental results, indicating that the improved immersed boundary method is efficient and reliable in dealing with the fluid–solid interaction problems. Copyright © 2015 John Wiley & Sons, Ltd.
A Practical One‐Pot Synthesis of Positron Emission Tomography (PET) Tracers via Nickel‐Mediated Radiofluorination
Authors: Zlatopolskiy Boris D. , Zischler Johannes , Urusova Elizaveta A. , Endepols Heike , Kordys Elena , Frauendorf Holm , Mottaghy Felix M. , Neumaier Bernd
Published: May 2015

Recently a novel method for the preparation of 18F‐labeled arenes via oxidative [18F]fluorination of easily accessible and sufficiently stable nickel complexes with [18F]fluoride under exceptionally mild reaction conditions was published. The suitability of this procedure for the routine preparation of clinically relevant positron emission tomography (PET) tracers, 6‐[18F]fluorodopamine (6‐[18F]FDA), 6‐[18F]fluoro‐l‐DOPA (6‐[18F]FDOPA) and 6‐[18F]fluoro‐m‐tyrosine (6‐[18F]FMT), was evaluated. The originally published base‐free method was inoperative. However, a “low base” protocol afforded protected radiolabeled intermediates in radiochemical conversions (RCCs) of 5–18 %. The subsequent deprotection step proceeded almost quantitatively (>95 %). The simple one‐pot two‐step procedure allowed the preparation of clinical doses of 6‐[18F]FDA and 6‐[18F]FDOPA within 50 min (12 and 7 % radiochemical yield, respectively). In an unilateral rat model of Parkinsons disease, 6‐[18F]FDOPA with high specific activity (175 GBq μmol−1) prepared using the described nickel‐mediated radiofluorination was compared to 6‐[18F]FDOPA with low specific activity (30 MBq μmol−1) produced via conventional electrophilic radiofluorination. Unexpectedly both tracer variants displayed very similar in vivo properties with respect to signal‐to‐noise ratio and brain distribution, and consequently, the quality of the obtained PET images was almost identical.
Effects of surface treatment of carbon fiber: Tensile property, surface characteristics, and bonding to epoxy
Authors: Wang Zike , Huang Xiangyu , Xian Guijun , Li Hui
Published: May 2015

In this article, effects of electrochemical oxidation and sizing treatment of PAN‐based carbon fibers (CFs) on the tensile properties, surface characteristics, and bonding to epoxy were investigated. As found, the electrochemical oxidation improves the tensile strength of single CF by 16.0%, due to weakening the surface stress concentration and smoothing the surface structure. Further sizing treatment shows a negligible effect on the tensile strength. Both oxidation and sizing treatments significantly improve the wettability and surface energies of CFs by introducing oxygen‐containing functional groups. Microbond test was conducted to characterize the interfacial shear strength (IFSS) between a single fiber and an epoxy droplet. The oxidation treatment increases IFSS slightly, which is due to the contradictory effects of the formation of chemical bonds between the resin and CFs, and the reduced mechanical interlocking. Further sizing treatment significantly enhances IFSS from 73.6 to 81.0 MPa, due to the formation of vast chemical bonds. Furthermore, the oxidation and sizing treatment can effectively reduce the degradation of IFSS to the hygrothermal ageing for the CF/epoxy system. POLYM. COMPOS., 37:2921–2932, 2016. © 2015 Society of Plastics Engineers
Crystallized polyarylene ether nitrile blends with improved thermal, mechanical, dielectric properties, and processability
Authors: Zheng Penglun , Pu Zejun , Jia Kun , Liu Xiaobo
Published: May 2015

In this work, the biphenol polyarylether nitrile (BP‐PEN) films with improved processability were prepared by blending low molecular weight (LMW) with high molecular weight (HMW) of BP‐PEN. The hybrid membrane exhibited excellent thermal stability and mechanical strength. The Tid values of the films were as high as 505°C–522°C. Melting behavior studies indicated that the crystallinity of LMW BP‐PEN was higher than that of HMW, which was confirmed by the X‐ray diffraction (XRD) patterns analysis as well. Scanning electron microscope (SEM) provided additional information on morphology and phase adhesion. Additionally, the polymer crystallinity dependent on dielectric properties of blends films is reported. Most importantly, it is found that the combination of LMW and HMW BP‐PEN would be an effective method to simultaneously increase the mechanical, thermal, dielectric properties, and polymer processability. POLYM. COMPOS., 38:126–131, 2017. © 2015 Society of Plastics Engineers
Multi‐gating injection molding to enhance the thermal conductivity of carbon fiber/polysulfone composite
Authors: Sun Deliang , Lin Guoming , Sui Guoxin , Hao Yulin , Yang Rui , Zhang Kai
Published: May 2015

Carbon fiber was blended into the polysulfone matrix by twin screw extruder. The polymer composites samples were prepared using four different processing technologies, the compression molding, edge‐gating injection molding, sprue‐gating injection molding, and the multi‐gating injection molding techniques. Among four techniques, the composite samples manufactured by multi‐gating injection molding technique got a higher value of thermal conductivity, which is due to the carbon fibers orientation and distribution. The experimental result indicated that the fiber orientation have a significant influence on the thermal conductivity of polymer composites. The thermal conductivity of sample made by multi‐gating injection molding was 1.82 W/(m·K) when the fiber content was 26 vol%, which was nearly twice than the values obtained by conventional technologies. POLYM. COMPOS., 38:185–191, 2017. © 2015 Society of Plastics Engineers
Rallying the Troops or Beating the Horses? How Project-Related Demands Can Lead to Either High-Performance or Abusive Supervision
Authors: Gallagher Erin C. , Mazur Alicia K. , Ashkanasy Neal M.
Published: May 2015

In today's high-pressure work environment, project managers are often forced to “do more with less.” We argue that this imperative can lead project managers to engage in either high-performance or abusive supervision behaviors. To understand this process, we develop a model and associated propositions linking a project manager's cognitive appraisal of project-related demands to high-performance work practices versus abusive supervision behaviors—both of which impact three project outcomes: stakeholder relationships, people-related project success factors, and employee well-being. We propose that the choice between high-performance work practices and abusive supervision behaviors is moderated by a project manager's personal resources (psychological capital, emotional intelligence, and dark triad personality).
Strategic and Cultural Misalignment: Knowledge Sharing Barriers in Project Networks
Authors: Solli-Sæther Hans , Karlsen Jan Terje , van Oorschot Kim
Published: May 2015

This article draws on theories from knowledge and project management to develop an understanding of how knowledge sharing is encouraged and hindered in the context of a multifirm network assembled to execute an innovative shipbuilding project. The empirical data are based on a qualitative case study, collected from in-depth face-to-face interviews in China and Norway, with the key people from a ship owner, shipbuilder, and ship technology supplier. The research indicates three interesting findings: First, differences in organizational culture (not national culture) hamper knowledge sharing. Second, a strategic misalignment made knowledge sharing difficult. Third, protecting knowledge by patenting and secrecy barely influenced the knowledge sharing processes. Based on previous research and lessons learned from case study experience, we suggest a framework to analyze challenges and links in project networks.
A Holistic View on Learning in Project-Based Organizations
Authors: Chronéer Diana , Backlund Fredrik
Published: May 2015

Although researchers have over the years highlighted the importance of managing and supporting learning in project-based settings, it still seems to be problematic. New project management capabilities are needed, such as systems thinking, which will allow project-based organizations to better cope with learning in the organizations. This article explores how Swedish project-based organizations within an engineering and construction context manage and support learning activities today and discusses, with the support of process management literature, how an “organizational-wide project learning process” could improve the prerequisites for learning in project-based organizations. Our findings from three project-based organizations indicate a lack of a holistic perspective on project learning. A conceptual model is proposed, with the aim of validating and promoting process thinking by introducing, for example, new roles responsible for intra-and inter-project learning, respectively.
Consideration on formation mechanism of aromatic polyamide hollow spheres prepared by reaction‐Induced phase separation
Authors: Nakayama Hirofumi , Fujitsu Yuji , Uchida Tetsuya , Yamazaki Shinichi , Kimura Kunio
Published: May 2015

Hollow spheres of poly(1,4‐phenylene‐5‐hydroxyisophthalamide) had been obtained by the reaction‐induced phase separation during polymerization of 5‐hydroxyisophthalic acid and 1,4‐phenylene diamine in an aromatic solvent. In this study, formation mechanism of the hollow spheres was considered from the view points of eliminated small molecules, polymer structure, and cross‐linking reaction. With respect to the eliminated small molecules, water was the most desirable to form gas‐bubbles in droplets compared with methanol and acetic acid, due to the insolubility into the polymerization system. Rigid polymer structure was also needed to prepare hollow spheres owing to the rapid solidification of droplets. Further, phenolic hydroxyl group in 5‐hydroxy‐1,3‐phenylene moiety caused the ester‐amide exchange reaction to form cross‐linked skin layer in the droplets. The efficient formation of the skin layer was important to encapsulate gas‐bubbles in the droplets, resulting in the formation of hollow structure. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1966–1974
Fabrication of Cu(In,Ga)Se2 solar cells with a single graded band profile
Authors: Nishimura Takahito , Kasashima Shunsuke , Hirai Yoshiaki , Kurokawa Yasuyoshi , Yamada Akira
Published: May 2015

It was found that Cu(In,Ga)Se2 (CIGS) solar cells with single graded (SG) band profile and average bandgap Eg(avg) of 1.15 eV has higher efficiency than double graded (DG) band profile with the same Eg(avg), despite no intentional bandgap‐widening at a CdS/CIGS interface in SG‐CIGS. To explain this contradiction, we focused on the band structure at the CdS/CIGS interface and proposed that the contradiction can be explained by the formation of an ordered vacancy chalcopyrite compound (OVC) layer on the surface of CIGS. Device simulation using wxAMPS revealed that if an OVC layer exists at the interface, conversion efficiency of SG‐CIGS solar cells overcomes that of DG‐CIGS solar cells due to suppression of surface recombination at the interface, leading to open‐circuit voltage (VOC) improvement. We applied the SG structure to CIGS solar cells with high Ga contents. As a result, the conversion efficiency of 15.1% for the SG‐CIGS solar cell with Eg(avg) of 1.4 eV was achieved, although in contrast, that of the DG‐CIGS solar cells was 12.9%. This efficiency is comparable to the highest efficiency in CIGS solar cells with high Ga contents. Therefore, SG band profile is promising structure and it is expected to achieve high efficiency predicted essentially in CIGS solar cells with high Ga contents.
Kinetic study of MOCVD of NiO films from bis‐(ethylcyclopentadienyl) nickel
Authors: Kondrateva A. S. , Mishin M. , Shakhmin A. , Baryshnikova M. , Alexandrov S. E.
Published: May 2015

NiO films were grown by metal‐organic chemical vapor deposition (MOCVD) using bis‐(ethylcyclopentadienyl) nickel [(EtCp)2Ni] and oxygen or ozone as precursors. The kinetic regularities of MOCVD processes were experimentally studied in the deposition temperature range 600‐820 K for the reaction systems: (EtCp)2Ni–O2–Ar and (EtCp)2Ni–O3–O2–Ar. The results obtained show that the deposition processes in the temperature range 600‐700 K are controlled by kinetics and the value of activation energy of the processes is 80±5 kJ·mol−1 in both cases. The growth process in the temperature region 700–840 K is controlled by mass transport. An introduction of ozone in the reaction gas phase led to nearly twofold decrease of deposition rate probably because of homogeneous reactions with (EtCp)2Ni. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
CVD synthesis and catalytic combustion application of chromium oxide films
Authors: Liang Jing , Pan Guan‐Fu , Fan Shi‐Bin , Cheng Wei‐Liang , Tian Zhen‐Yu
Published: May 2015

Chromiumoxide (Cr2O3) thin films were controllably synthesized by pulsed‐spray evaporation chemical vapor deposition (PSE‐CVD) for deep oxidation of propene. The effect of substrate temperature on the growth kinetics and morphology of the films was investigated. The prepared samples were comprehensively characterized with respect to structure, morphology and surface composition with XRD, SEM and XPS, respectively. An in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was involved to reveal the surface mechanism occurred on Cr2O3. The growth rate exhibited a linear behavior when the temperature increase from 300 to 450 °C. The structural analysis indicated that a pure phase of Cr2O3 was obtained at 425 °C. The catalytic tests showed that Cr2O3 films prepared on flexible substrates exhibited advantages for the catalytic oxidation of C3H6. Based on the DRIFTS observations, the Langmuir‐Hinshelwood (L‐H) mechanism was proposed for C3H6 over Cr2O3 films. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An adaptive covariance relaxation method for ensemble data assimilation
Authors: Ying Yue , Zhang Fuqing
Published: May 2015

For ensemble filters, accounting for unrepresented errors by inflating the ensemble perturbations can help improve filter performance. However, tuning the inflation factor can be costly, thus demanding adaptive covariance inflation (ACI) algorithms that give an online estimate of a temporally varying inflation factor. Additionally, a spatially varying inflation factor should be used to account for an irregular observation network. Anderson's adaptive inflation method offers a spatially and temporally varying inflation factor estimated from innovation statistics using a hierarchical Bayesian approach. In this study, we propose an alternative adaptive covariance relaxation (ACR) method that estimates a relaxation parameter online. Instead of treating inflation parameters as spatially varying random variables as in Anderson's method, the relaxation‐to‐prior‐spread method provides an ensemble spread reduction term that serves as a spatial mask to account for an irregular observation network. We demonstrate with a set of experiments using the 40‐variable Lorenz model that the ACR method is able to improve filter performance with the presence of sampling/model errors over a range of severity. Its reliability and ease of implementation suggest potential for future applications with atmospheric models.
Nanoscale Heterogeneity of the Molecular Structure of Individual hIAPP Amyloid Fibrils Revealed with Tip‐Enhanced Raman Spectroscopy
Authors: vandenAkker Corianne C. , Deckert‐Gaudig Tanja , Schleeger Michael , Velikov Krassimir P. , Deckert Volker , Bonn Mischa , Koenderink Gijsje H.
Published: May 2015

Type 2 diabetes mellitus is characterized by the pathological deposition of fibrillized protein, known as amyloids. It is thought that oligomers and/or amyloid fibrils formed from human islet amyloid polypeptide (hIAPP or amylin) cause cell death by membrane damage. The molecular structure of hIAPP amyloid fibrils is dominated by β‐sheet structure, as probed with conventional infrared and Raman vibrational spectroscopy. However, with these techniques it is not possible to distinguish between the core and the surface structure of the fibrils. Since the fibril surface crucially affects amyloid toxicity, it is essential to know its structure. Here the surface molecular structure and amino acid residue composition of hIAPP fibrils are specifically probed with nanoscale resolution using tip‐enhanced Raman spectroscopy (TERS). The fibril surface mainly contains unordered or α‐helical structures, in contrast to the β‐sheet‐rich core. This experimentally validates recent models of hIAPP amyloids based on NMR measurements. Spatial mapping of the surface structure reveals a highly heterogeneous surface structure. Finally, TERS can probe fibrils formed on a lipid interface, which is more representative of amyloids in vivo.
Die neue Straßenbrücke in Toruń, Polen – Teil 2: Nachweise
Authors: Malinowski Maciej , Banaś Anna , Cywiński Zbigniew , Wąchalski Krzysztof
Published: May 2015

Als Fortsetzung von Teil 1 [1], der über den Entwurf und den Bau der neuen, die Weichsel querenden Straßenbrücke in Toruń (deutsch: Thorn) berichtet, geht es im Folgenden um die theoretischen und experimentellen Nachweise zum Montageprozess und zu Probebelastungen. Somit ist eine umfassende Beurteilung der beschriebenen, herausragenden Ingenieursleistung gegeben.

The new road bridge in Toruń, Poland – Part 2: structural design calculation. As a continuation of part 1 [1], which represents the design and the construction of the road bridge crossing the river Vistula in Toruń (Thorunium), now it will be turned over to the theoretical and experimental procedures that have been applied in the mentioned bridge mounting and load tests. Consequently, a full judgement of the mentioned outstanding engineer achievement is available.
Schubtragfähigkeit und M‐V‐Interaktion von Flachdecken mit integrierten hohlkastenförmigen Stahlprofilen
Authors: Schäfer Markus
Published: May 2015

Flachdecken mit integrierten Stahlprofilen in Verbundbauweise zeichnen sich vor allem durch die schlanke Bauweise mit geringen Deckenhöhen aus. In den letzten Jahren haben sich neben den typischen Querschnitten aus gewalzten Profilen mit untergeschweißter Gurtplatte immer mehr hohlkastenähnliche Profilformen durchgesetzt. Bei diesen Systemen kann zur Steigerung der Querkrafttragfähigkeit ein hybrides Fachwerkmodell abgeleitet werden, bei dem neben der Querkrafttragfähigkeit des Stahlprofils auch die Tragfähigkeit des Betons angerechnet wird. Aufgrund der daraus resultierenden zusätzlichen Spannungen im Stahlprofil muss die Momenten‐Querkraft‐Interaktionsbeziehung erweitert werden.

Shear resistance and M‐V‐Interaction of Slim‐Floor‐systems with integrated steel‐box sections – Approach of a hybrid truss model for the shear design. Shallow‐floor slabs with integrated steel profiles in composite behavior are mainly characterized by the slim design. Parallel to the traditional sections consisting of rolled profiles with an additional bottom plate also floor‐slabs with integrated steel‐box sections have gained widespread adoption in practice in the recent years. Because of the sheathing of the concrete by the steel section a hybrid truss model with a compression strut in the concrete section is developed, increasing the shear resistance of these sections. Due to the additional steel stresses resulting by the truss model, the relationship for the interaction between moment and vertical shear forces is to expand.
Design of triple‐band antenna using S‐shaped patch fed by cross strip line for WLAN and WiMAX applications
Authors: Chawanonphithak Yuktitath , Phongcharoenpanich Chuwong
Published: May 2015

This paper presents a simple triple‐band S‐shaped patch antenna fed by a cross strip line for both WLAN and WiMAX applications. It is operated at the triple bands of 2.4 and 5.2 GHz for WLAN and 3.5 GHz for WiMAX. The antenna, designed on an FR4 substrate with a thickness of 1.6 mm and relative permittivity of 4.4, is fed by a 50‐Ω microstrip line, and is of size 25 × 35 mm. The simulated and measured results of |S11|, gains, and radiation patterns are presented. The measured results show that the triple‐band antenna achieves a broad operating bandwidth of 2.36–2.54, 3.27–3.69, and 5.16–5.48 GHz for a 10‐dB return loss (i.e. |S11|<−10 dB). The gains of the antenna measured at 2.4, 3.5, and 5.2 GHz frequencies are 1.87, 1.95, and 3.82, respectively. The radiation pattern of the antenna is omnidirectional. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.