bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of surface‐grafted poly(N‐isopropylacrylamide) and poly(carboxylic acid)—Iron particles via atom transfer radical polymerization for biomedical applications
Authors: Sutrisno Joko , Fuchs Alan , Evrensel Cahit 
Published: December 2013

ABSTRACTThis research relates to the preparation and characterization of surface grafted poly(N‐isopropylacrylamide) and poly(carboxylic acid)–micron‐size iron particles via atom transfer radical polymerization (ATRP). The surface grafted polymers–iron particles result in multifunctional materials which can be used in biomedical applications. The functionalities consist of cell targeting, imaging, drug delivery, and immunological response. The multifunctional materials are synthesized in two steps. First, surface grafting is used to place polymer molecules on the iron particles surface. The second step is conjugation of the bio‐molecules onto the polymer backbone. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy were used to confirm the presence of polymers on the iron particles. The thickness of the grafted polymers and glass transition temperature of the surface grafted polymers were determined by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The covalent bond between grafted polymers and iron particles caused higher glass transition temperature as compared with nongrafted polymers. The ability to target the bio‐molecule and provide fluorescent imaging was simulated by conjugation of rat immunoglobulin and fluorescein isothiocyanate (FITC) labeled anti‐rat. The fluorescence intensity was determined using flow cytometry and conjugated IgG‐FITC anti‐rat on iron particles which was imaged using a fluorescence microscopy. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40176.
Salt‐free softening by thermo‐reversible ion‐adsorbing hydrogels
Authors: Custers Johannes P. A. , Stemkens Léon F. S. , Sablong Rafael , van Asseldonk Dirk T. A. , Keurentjes Jos T. F. 
Published: December 2013

ABSTRACTIn this article, we demonstrate the properties of a hydrogel capable of adsorbing calcium cations from aqueous streams at ambient temperatures (10–25°C) and showing almost complete desorption of the bound calcium ions at slightly elevated temperatures (40–50°C). Successful breakthrough experiments in a fixed bed column set‐up show the potential of the hydrogel in softening water streams from 150 ppm toward <10 ppm hardness levels. The regeneration ability is based on the thermo‐reversible internal ion pair–formation mechanism of the hydrogel. Additionally, it was shown that the thermo‐reversible adsorption mechanism was successful for magnesium and copper ions too. The exploration of the properties of hydrogel CS‐1B14 is the first step in the development of sustainable water‐softening processes, both at industrial scale as well as for household applications, using low‐grade residual heat to regenerate these gels. In this way, the use of concentrated brine streams, acid/caustic treatment, or high regeneration temperatures is avoided. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40216.
Stable Encapsulation of Acrylate Esters in Networked Molecular Capsules
Authors: Ning Guo‐Hong , Inokuma Yasuhide , Fujita Makoto 
Published: December 2013

AbstractReactive acrylate esters were encapsulated in the cavity of networked molecular capsules in a single‐crystal‐to‐single‐crystal fashion. Owing to the encapsulation effect, acrylates inside the capsules do not undergo polymerization upon irradiation with UV light or heating, while the guest molecules can be quantitatively extracted by treatment with toluene.
The 2.05‐helix in hetero‐oligopeptides entirely composed of Cα,α‐disubstituted glycines with both side chains longer than methyls
Authors: Crisma Marco , Peggion Cristina , Moretto Alessandro , Banerjee Raja , Supakar Subhrangshu , Formaggio Fernando , Toniolo Claudio 
Published: December 2013

ABSTRACTThe existence of the very uncommon, but potentially quite interesting, multiple, consecutive fully‐extended conformation (2.05‐helix) has been already clearly demonstrated in homo‐oligopeptides based on quaternary α‐amino acids with both side chains longer than methyls, but not cyclized on the α‐carbon atom. To extend the scope of this research, in this work we investigated the occurrence of this flat 3D‐structure in hetero‐oligopeptides, each composed of two or three different residues of that class. The synthesis of a terminally protected peptide series to the tetrapeptide level was carried out by solution methods. The resulting oligomers were chemically and conformationally characterized. The data obtained point to an overwhelming population of the fully‐extended conformation in CDCl3. However, a solvent‐driven switch to a predominant 310‐helical structure was seen in CD3CN. A delicate, local balance between these two conformations is confirmed to occur in the crystalline state. Molecular dynamics simulations in CHCl3 on a hetero‐tetrapeptide converged to the fully‐extended conformation even starting from the 310‐helical structure. © 2013 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 145–158, 2014.
MRI-defined height of rectal tumours
Authors: Keller D S , Paspulati R , Kjellmo A , Rokseth K M , Bankwitz B , Wibe A , Delaney C P 
Published: December 2013

Abstract

Background
There is no standard for reporting rectal cancer distances from the distal resection margin in the literature. The objective was to demonstrate the importance of rectal cancer measurement from a standardized point.

Methods
Review of databases at two international institutions identified 50 patients with rectal adenocarcinoma within 15 cm of the anal verge (AV), who had preoperative magnetic resonance imaging (MRI) and underwent surgery with curative intent. Expert radiologists reviewed the magnetic resonance images for anatomical distances from the anorectal ring (ARR) to the AV, from the ARR to the dentate line (DL), and from the DL to the AV. Anatomical measurements were compared with preoperative measurements to assess reporting inconsistencies.

Results
Fifty patients with rectal adenocarcinoma were included in the study. The mean(s.d.) anatomical distance was 1·66(0·61) cm from the ARR to the DL, 3·78(0·61) cm from the ARR to the AV (maximum 5·5 cm) and 2·11(0·10) cm from the DL to the AV. The mean radiological distance from the distal tumour was 2·90(1·60) (median 3·2, range 0–7·5) cm to the ARR, 4·36(3·20) (median 4·2, range −0·5 to 12·8) cm to the DL and 6·13(3·39) (median 6·0, range 0–14·1) cm to the AV. There was a significant difference in the distal tumour margin between measurements made by the expert radiologists and reported preoperative measurements (P &lt; 0·001). Significant differences were also found between the expert radiologists' MRI and rigid proctoscopic measurements (P = 0·025).

Conclusion
There was up to 5·5 cm variation, depending on which landmark was chosen for reporting the distal margin of rectal cancer. This has potential implications for surgical planning, interpreting radiological images and comparative studies.
Boards and Sustainability: the Contingent Influence of Director Interlocks on Corporate Environmental Performance
Authors: Ortiz‐de‐Mandojana Natalia , Aragon‐Correa Juan Alberto 
Published: December 2013

AbstractThis paper highlights the importance of a firm's board with respect to sustainability issues by analysing the relationship between director interlocks, i.e. directors who simultaneously belong to the boards of directors of several companies, and a firm's environmental performance. The previous literature has focused on the influence of firm‐level resources on corporate environmental performance. This study utilizes insights from a resource‐based view and research on social capital to demonstrate that the environmental performance of a firm is also influenced by the difficult‐to‐imitate capabilities that are embedded in the network relationships of its directors. Our results support a contingency perspective of the social capital theory that finds that director interlocks are positively connected with the environmental performance of a firm in two specific situations: (1) when the firm is linked to a larger parent company and (2) in cases of low and high levels of interlock diversity. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment.
In Situ Observation of Cu–Ni Alloy Nanoparticle Formation by X‐Ray Diffraction, X‐Ray Absorption Spectroscopy, and Transmission Electron Microscopy: Influence of Cu/Ni Ratio
Authors: Wu Qiongxiao , Duchstein Linus D. L. , Chiarello Gian Luca , Christensen Jakob M. , Damsgaard Christian D. , Elkjær Christian F. , Wagner Jakob B. , Temel Burcin , Grunwaldt Jan‐Dierk , Jensen Anker D. 
Published: December 2013

AbstractSilica‐supported, bimetallic Cu–Ni nanomaterials were prepared with different ratios of Cu to Ni by incipient wetness impregnation without a specific calcination step before reduction. Different in situ characterization techniques, in particular transmission electron microscopy (TEM), X‐ray diffraction (XRD), and X‐ray absorption spectroscopy (XAS), were applied to follow the reduction and alloying process of Cu–Ni nanoparticles on silica. In situ reduction of Cu–Ni samples with structural characterization by combined synchrotron XRD and XAS reveals a strong interaction between Cu and Ni species, which results in improved reducibility of the Ni species compared with monometallic Ni. At high Ni concentrations silica‐supported Cu–Ni alloys form a homogeneous solid solution of Cu and Ni, whereas at lower Ni contents Cu and Ni are partly segregated and form metallic Cu and Cu–Ni alloy phases. Under the same reduction conditions, the particle sizes of reduced Cu–Ni alloys decrease with increasing Ni content. Estimates of the metal surface area from sulfur chemisorption and from the XRD particle size generally agree well on the trend across the composition range, but show some disparity in terms of the absolute magnitude of the metal area. This work provides practical synthesis guidelines towards preparation of Cu–Ni alloy nanomaterials with different Cu/Ni ratios, and insight into the application of different in situ techniques for characterization of the alloy formation.
One‐Pot Conversion of Carbon Dioxide, Ethylene Oxide, and Amines to 3‐Aryl‐2‐oxazolidinones Catalyzed with Binary Ionic Liquids
Authors: Wang Binshen , Elageed Elnazeer H. M. , Zhang Dawei , Yang Sijuan , Wu Shi , Zhang Guirong , Gao Guohua 
Published: December 2013

AbstractAn effective one‐pot method for the conversion of carbon dioxide, ethylene oxide, and amines to 3‐aryl‐2‐oxazolidinones has been developed. This one‐pot method consists of two parallel reactions and a subsequent cascade reaction between the two products of the corresponding parallel reactions. Notably, the binary ionic liquids of 1‐butyl‐3‐methyl‐imidazolium bromide and 1‐butyl‐3‐methyl‐imidazolium acetate demonstrate a synergistic catalytic effect on this new strategy. 1‐Butyl‐3‐methyl‐imidazolium bromide is essential in two parallel reactions owing to the good nucleophilicity and leaving ability of bromide, and 1‐butyl‐3‐methyl‐imidazolium acetate plays a dominant role in the subsequent cascade reaction owing to the strong basicity of acetate. In addition, the binary ionic liquids can be used thrice without significant loss of catalytic activity.
Functional carbo‐Butadienes: Nonaromatic Conjugation Effects through a 14‐Carbon, 24‐π‐Electron Backbone
Authors: Rives Arnaud , Maraval Valérie , Saffon‐Merceron Nathalie , Chauvin Remi 
Published: December 2013

AbstractA systematic study of carbo‐butadiene motifs not embedded in an aromatic carbo‐benzene ring is described. Dibutatrienylacetylene (DBA) targets R1C(R)CCC(Ph)C≡CC(Ph)CCC(R)R2 are devised, in which R is C≡CSiiPr3 and R1 and R2 are R, H, or 4‐X‐C6H4, with the latter including three known representatives (X: H, NMe2, or NH2). The synthesis method is based on the SnCl2‐mediated reduction of pentaynediols prepared by early or late divergent strategies; the latter allows access to a OMe–NO2 push–pull diaryl‐DBA. If R1 and R2 are H, an over‐reduced dialkynylbutatriene (DAB) with two allenyl caps was isolated instead of the unsubstituted DBA. If R1=R2=R, the tetraalkynyl‐DBA target was obtained, along with an over‐reduced DBA product with a 12‐membered 1,2‐alkylidene‐1H2,2H2‐carbo‐cyclobutadiene ring. X‐ray crystallography shows that all of the acyclic DBAs adopt a planar trans–transoid–trans configuration. The maximum UV/Vis absorption wavelength is found to vary consistently with the overall π‐conjugation extent and, more intriguingly, with the π‐donor character of the aryl X substituents, which varies consistently with the first (reversible) reduction potential and first (irreversible) oxidation peak, as determined by voltammetry.
Highly Curved Bowl‐Shaped Fragments of Fullerenes: Synthesis, Structural Analysis, and Physical Properties
Authors: Chen Min‐Kuan , Hsin Hsin‐Ju , Wu Tsun‐Cheng , Kang Bo‐Yan , Lee Yen‐Wei , Kuo Ming‐Yu , Wu Yao‐Ting 
Published: December 2013

AbstractHighly curved buckybowls 3, 4, and 5 were synthesized from planar precursors, fluoranthenes 8, benzo[k]fluoranthenes 10 and naphtho[1,2‐k]‐cyclopenta[cd]fluoranthenes 12, respectively, using straightforward palladium‐catalyzed cyclization reactions. These fluoranthene‐based starting materials were easily prepared from 1,8‐bis(arylethynyl)naphthalenes 6. Both buckybowls 3 and 4 are fragments of C60, whereas 5 is a unique subunit of C70. The curved structures were identified by X‐ray crystallography, and they are deep bowls. The maximum π‐orbital axis vector (POAV) pyramidalization angle in both 3 and 4 is 12.8°. Such a high curvature is very rarely obtained. Buckybowls 5 are less curved than the others because they have a lower density of five‐membered rings, analogous to the tube portion of C70. Cyclopentaannulation increases the bowl depths of 3 and 4, but not the maximum POAV pyramidalization angle. Among the eight buckybowls studied herein, five form polar crystals. The bowl‐to‐bowl inversion dynamics of these buckybowls can be classified into two types; one has a planar transition structure, whereas the other has an S‐shaped transition structure. A larger longitudinal length of these buckybowls corresponds to a stronger preference for the latter. The photophysical properties of these buckybowls were examined and compared with those of C60 and C70. Buckybowls 5 have absorption bands at wavelengths greater than 450 nm, which are similar to those of C70. The chiral resolution of the mono‐substituted buckybowl 4 ac was also studied by using HPLC with a chiral column.
ChemInform Abstract: Bulk Compound Synthesis and Oxygen Deficiency Effect on Electronic and Magnetic Properties of the Zn‐Based Oxyarsenide LaZnAsO1‐δ.
Authors: Wang Xia , Guo Yanfeng , Li Baoe , Tsujimoto Yoshihiro , Yamaura Kazunari 
Published: December 2013

AbstractOxygen‐deficient title compounds with 0 ≤ δ ≤ 0.35 are synthesized from stoichiometric amounts of LaAs, ZnO, and Zn (belt‐type high‐pressure apparatus, Au capsule, Ar, 6 GPa, 1300 °C, 2 h).
ChemInform Abstract: Electrochemical Synthesis of Ti5Si3 in CaCl2 Melt.
Authors: Jiao Handong , Wang Qiuyu , Ge Jianbang , Sun Haobo , Jiao Shuqiang 
Published: December 2013

AbstractThe titleompound is prepared by electro‐deoxidation of a TiO2/SiO2 composite in molten CaCl2 electrolyte at 900 °C.
Size Resolved Droplet Velocity Measurements in an Electrostatic Precipitator
Authors: Horender Stefan , Schaub Frank , Sommerfeld Martin 
Published: December 2013

AbstractDie Partikelgeschwindigkeiten in einem Plattenelektroabscheider wurden mittels eines Phasen‐Doppler‐Anemometers gemessen. Die Seedingtröpfchen zeigten höhere Driftgeschwindigkeiten als aufgrund der Feldwirkung erwartet und bestätigen damit den Einfluss des Ionenwindes. Die relevanten Gradienten der Seedingpartikelkonzentration erhöhten die Driftgeschwindigkeit. Die Wanderungsgeschwindigkeiten der Wassertröpfchen nahmen linear mit der Topfengröße zu und waren ebenso vom Konzentrationsgradienten beeinflusst. Somit konnte die Summe aus Ionenwind und Drift aufgrund der Gradientendiffusion der Tröpfchen abgeschätzt werden.
SEED: solar energy‐aware efficient scheduling for data centers
Authors: Jing Chao , Zhu Yanmin , Li Minglu 
Published: December 2013

SUMMARYIt is well known that data centers are consuming a large amount of energy that incurs significant financial and environmental costs. Recently, there has been an increasing interest in utilizing green energy for data centers, where green energy sources include solar and wind. This paper studies the crucial problem of maximizing the utilization of green energy through scheduling complex jobs in data centers in order to reduce the use of traditional brown energy. However, it is highly challenging for data centers to make use of green energy. First, the availability of typical green energy is variable to dynamic changes of natural environments, for example, weather. Second, although predictions can be made for the future availability of green energy, it is inevitable that such predictions have errors. Third, jobs are associated with strict deadlines, and it is required that jobs are completed before their deadlines. Finally, because the reliability in a data center relies upon temperature, the awareness of temperature should be taken into account while maximizing the green energy. In this paper, we consider online scheduling of jobs whose arrivals to the data center system dynamically. In addition, we explicitly take the power consumption of switches into account when scheduling jobs onto computing nodes. Two solar energy‐aware algorithms called SEEDMin and SEEDMax have been proposed. Then, we extend SEED to RSEED with the awareness of reliability. To evaluate the effectiveness of the proposed algorithms, comprehensive simulations have been conducted, and the proposed algorithms are compared with other state‐of‐art algorithms. Experimental results demonstrate that both SEEDMin and SEEDMax can significantly increase the utilization of solar energy without violating job deadlines and overall energy budget. The amount of solar energy utilized by SEEDMin and SEEDMax is 33.4%and35.3% larger than that of two traditional scheduling algorithms, MinMin and MinMax, respectively. Also, it can be seen that RSEED greatly improves the reliability by decreasing the temperature. Copyright © 2013 John Wiley & Sons, Ltd.
Poly(ethylene glycol)‐Based Ionic Liquids: Properties and Uses as Alternative Solvents in Organic Synthesis and Catalysis
Authors: Cecchini Martina Maya , Charnay Clarence , De Angelis Francesco , Lamaty Frédéric , Martinez Jean , Colacino Evelina 
Published: December 2013

AbstractPEG‐based ionic liquids are a new appealing group of solvents making the link between two distinct but very similar fluids: ionic liquids and poly(ethylene glycol)s. They find applications across a range of innumerable disciplines in science, technology, and engineering. In the last years, the possibility to use these as alternative solvents for organic synthesis and catalysis has been increasingly explored. This Review highlights strategies for their synthesis, their physical properties (critical point, glass transition temperature, density, rheological properties), and their application in reactions catalyzed by metals (such as Pd, Cu, W, or Rh) or as organic solvent (for example for multicomponent reactions, organocatalysis, CO2 transformation) with special emphasis on their toxicity, environmental impact, and biodegradability. These aspects, very often neglected, need to be considered in addition to the green criteria usually considered to establish ecofriendly processes.
Growing season net ecosystem CO2 exchange of two desert ecosystems with alkaline soils in Kazakhstan
Authors: Li Longhui , Chen Xi , van der Tol Christiaan , Luo Geping , Su Zhongbo 
Published: December 2013

AbstractCentral Asia is covered by vast desert ecosystems, and the majority of these ecosystems have alkaline soils. Their contribution to global net ecosystem CO2 exchange (NEE) is of significance simply because of their immense spatial extent. Some of the latest research reported considerable abiotic CO2 absorption by alkaline soil, but the rate of CO2 absorption has been questioned by peer communities. To investigate the issue of carbon cycle in Central Asian desert ecosystems with alkaline soils, we have measured the NEE using eddy covariance (EC) method at two alkaline sites during growing season in Kazakhstan. The diurnal course of mean monthly NEE followed a clear sinusoidal pattern during growing season at both sites. Both sites showed significant net carbon uptake during daytime on sunny days with high photosynthetically active radiation (PAR) but net carbon loss at nighttime and on cloudy and rainy days. NEE has strong dependency on PAR and the response of NEE to precipitation resulted in an initial and significant carbon release to the atmosphere, similar to other ecosystems. These findings indicate that biotic processes dominated the carbon processes, and the contribution of abiotic carbon process to net ecosystem CO2 exchange may be trivial in alkaline soil desert ecosystems over Central Asia.
Highly Selective H2O2‐Based Oxidation of Alkylphenols to p‐Benzoquinones Over MIL‐125 Metal–Organic Frameworks
Authors: Ivanchikova Irina D. , Lee Ji Sun , Maksimchuk Nataliya V. , Shmakov Alexander N. , Chesalov Yurii A. , Ayupov Artem B. , Hwang Young Kyu , Jun Chul‐Ho , Chang Jong‐San , Kholdeeva Oxana A. 
Published: December 2013

AbstractThe titanium‐based metal–organic framework MIL‐125 and its amine‐functionalized analog, MIL‐125_NH2, have been synthesized and characterized by elemental analysis, XRD, SEM, TEM, N2 adsorption measurements, and spectroscopic techniques, including FTIR, Raman, and DR UV/Vis spectroscopy. Catalytic properties of MIL‐125 and MIL‐125_NH2 were evaluated in the selective oxidation of two representative alkyl‐substituted phenols, 2,3,6‐trimethylphenol and 2,6‐di‐tert‐butylphenol, with the clean oxidant H2O2. With both MIL‐125 and MIL‐125_NH2, the selectivity toward the corresponding p‐benzoquinones was 100 %. Samples of MIL‐125 with different sizes of crystallites (0.5, 1.5, and 5 μm) demonstrated similar reaction rates, thus indicating the absence of diffusion limitations. The efficiency of the oxidant utilization and stability of the MIL‐125 structure increased upon decreasing the amount of water in the reaction mixture. Even if the structural integrity of MIL‐125 was destroyed by the reaction medium, the metal–organic framework acted as a precursor for the highly active, selective, and recyclable catalyst. The MIL‐125‐derived materials were stable toward titanium leaching, behaved as true heterogeneous catalysts, and could easily be recovered by filtration and reused several times without the loss of the catalytic properties.
Phosphorescent C∧C* Cyclometalated PtII Dibenzofuranyl‐NHC Complexes – An Auxiliary Ligand Study
Authors: Tronnier Alexander , Nischan Nicole , Metz Stefan , Wagenblast Gerhard , Münster Ingo , Strassner Thomas 
Published: December 2013

AbstractNeutral C∧C* cyclometalated PtII NHC complexes have recently emerged as a new class of phosphorescent emitters with high quantum efficiencies, short decay lifetimes and high thermal stability, which makes them promising candidates for OLED applications. Herein, we report investigations on the photophysical properties of seven new PtII complexes containing a chelating NHC dibenzofuranyl ligand (3‐methyl‐1‐dibenzo[b,d]furan‐4‐ylimidazole) and a bidentate monoanionic auxiliary ligand. All complexes have been fully characterized including extensive NMR studies (COSY, HSQC, HMBC, NOESY, 195Pt NMR), three of them also by solid‐state structures. The extraordinary influence of the auxiliary ligands on the photoluminescence properties is demonstrated by quantum yields ranging from 0 % to 91 % in amorphous PMMA films at room temperature. DFT calculations were performed in order to investigate the nature of the emissive states in more detail.