bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapidly serum‐degradable hydrogel templating fabrication of spherical tissues and curved tubular structures
Authors: Sakai Shinji , Inagaki Hitomi , Liu Yang , Matsuyama Tomohiro , Kihara Takanori , Miyake Jun , Kawakami Koei , Taya Masahito 
Published: May 2012

AbstractDevelopment of the techniques for fabricating three‐dimensional tissues still poses significant challenges for tissue engineering. We used hydrogels obtained from phenol‐substituted amylopectin (AP‐Ph) as templates for preparing multicellular spherical tissues (MSTs) and endothelialized curved tubular structures in type I collagen gel. AP‐Ph hydrogel microparticles of diameter 200 µm and fibers of diameter 500 µm disappeared within hours of soaking in a serum‐containing medium. HeLa cells and human endothelial cells were enclosed in the microparticles and hydrogel fibers, respectively, and then embedded in Ca‐alginate microcapsules or the collagen gel. The enclosed cells were released in cavities formed by hydrogel degradation in the serum‐containing medium. The released HeLa cells in the spherical cavities grew and formed MSTs, eventually filling the cavities. The spherical tissues were easily harvested by liquefying the Ca‐alginate hydrogel microcapsule membrane by chelation using sodium citrate. The released endothelial cells grew on the tubular cavity surfaces and formed tubular structures. An endothelial cell network was formed by cell migration into the collagen gel. These results demonstrate the potential of serum‐degradable AP‐Ph hydrogels in constructing three‐dimensional tissues. Biotechnol. Bioeng. 2012; 109: 2911–2919. © 2012 Wiley Periodicals, Inc.
Integration of mixing, heat transfer, and biochemical reaction kinetics in anaerobic methane fermentation
Authors: Wu Binxin 
Published: May 2012

AbstractAn extensive investigation of anaerobic methane fermentation requires identifying the relationship between the physical environment and biological process. In this study, a computational fluid dynamics (CFD) technique was used to characterize bacterial fermentation mechanisms intertwined with mixing and heat transfer in anaerobic digesters. The results demonstrate that the methane yield remains almost unchanged while the energy efficiency decreases with increasing mixing power in a complete‐mix digester, and that the energy output increases nonlinearly with the increase in heating energy in a plug‐flow digester. The CFD method can be applied to other bioreactors to gain valuable insights into their behavior as well. Integrating flow and temperature with kinetic behavior for anaerobic digestion not only solves the controversy about how mixing influences the digestive process, but also assists in optimizing the digester design and increasing the efficiency of energy conversion, and additionally, provides a reference for improving the mixing guidelines recommended by the U.S. Environmental Protection Agency. Biotechnol. Bioeng. 2012; 109: 2864–2874. © 2012 Wiley Periodicals, Inc.
An activated sludge modeling framework for xenobiotic trace chemicals (ASM‐X): Assessment of diclofenac and carbamazepine
Authors: Plósz Benedek Gy. , Langford Katherine H. , Thomas Kevin V. 
Published: May 2012

AbstractConventional models for predicting the fate of xenobiotic organic trace chemicals, identified, and calibrated using data obtained in batch experiments spiked with reference substances, can be limited in predicting xenobiotic removal in wastewater treatment plants (WWTPs). At stake is the level of model complexity required to adequately describe a general theory of xenobiotic removal in WWTPs. In this article, we assess the factors that influence the removal of diclofenac and carbamazepine in activated sludge, and evaluate the complexity required for the model to effectively predict their removal. The results are generalized to previously published cases. Batch experimental results, obtained under anoxic and aerobic conditions, were used to identify extensions to, and to estimate parameter values of the activated sludge modeling framework for Xenobiotic trace chemicals (ASM‐X). Measurement and simulation results obtained in the batch experiments, spiked with the diclofenac and carbamazepine content of preclarified municipal wastewater shows comparably high biotransformation rates in the presence of growth substrates. Forward dynamic simulations were performed using full‐scale data obtained from Bekkelaget WWTP (Oslo, Norway) to evaluate the model and to estimate the level of re‐transformable xenobiotics present in the influent. The results obtained in this study demonstrate that xenobiotic loading conditions can significantly influence the removal capacity of WWTPs. We show that the trace chemical retransformation in upstream sewer pipes can introduce considerable error in assessing the removal efficiency of a WWTP, based only on parent compound concentration measurements. The combination of our data with those from the literature shows that solids retention time (SRT) can enhance the biotransformation of diclofenac, which was not the case for carbamazepine. Model approximation of the xenobiotic concentration, detected in the solid phase, suggest that between approximately 1% and 16% of the total solid carbamazepine and diclofenac concentrations, respectively, is due to sorption—the remainder being non‐bioavailable and sequestered. We demonstrate the effectiveness of the model's predictive power over conventional tools in a statistical analysis, performed at four levels of structural complexity. To assess WWTP retrofitting needs to remove xenobiotic trace chemicals, we suggest using mechanistic models, e.g., ASM‐X, in regional risk assessments. For preliminary evaluations, we present operating charts that can be used to estimate average xenobiotic removal rates in WWTPs as a function of SRT and the xenobiotics mass loads normalised to design treatment capacity. Biotechnol. Bioeng. 2012; 109: 2757–2769. © 2012 Wiley Periodicals, Inc.
Implementing a new approach for the design of an e‐learning platform in engineering education
Authors: Violante Maria Grazia , Vezzetti Enrico 
Published: May 2012

ABSTRACTModern corporations, institutions, universities and schools consider e‐education as a way of educating larger groups of students in less time and of reducing the use of various resources. Since setting up a web‐system for e‐education requires a significant amount of time, as well as the necessity of having a computer and other resources, the assessment of the goals and desired effects of the online system should be made in the preparation phase. It is important to highlight that only putting course contents on the web, without using appropriate pedagogical models and principles, without appropriate means of communication between participants and instructors and without the use of modern information technologies to present the learning content is not enough to fulfil educational goals. It should be noted that, after the substantial initial investment and excitement about the possibilities of e‐education, many sources of difficulty and dissatisfaction regarding online learning have emerged. Most e‐learning studies propose possible improvements in course material, with little attempt to explore the learners' dimension, context, pedagogical considerations or technology aspects. In this article, we have analysed the aspects that need to be considered when designing an e‐learning platform for engineering education and we have proposed a methodology, based on the Quality Function Deployment approach, useful for the preparation phase of distance learning systems. Finally, we have explained the impact of new information technologies (Web3D technologies) on online engineering education and highlighted how these tools have been implemented in the e‐learning platforms for mechanical engineering that we have developed.© 2012 Wiley Periodicals, Inc. Comput Appl Eng Educ 22:708–727, 2014; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21564
In Situ Monitoring of Cocrystallization Processes – Complementary Use of Sensing Technologies
Authors: Gagniere E. , Puel F. , Mangin D. , Valour J.‐P. , Rivoire A. , Galvan J.‐M. , Monnier O. , Klein J.‐P. 
Published: May 2012

AbstractTwo in situ process analytical technologies were used to investigate a cocrystallization process: a focused beam reflectance measurement probe and a video probe. The cocrystallizations were conducted batch‐wise in a stirred thermostatted vessel with carbamazepine and nicotinamide. The experiments were started in three domains of the phase solubility diagram. When carbamazepine crystals were also formed, a solution mediated phase transition from carbamazepine crystals towards cocrystals was initiated by the addition of the cocrystallizing agent (nicotinamide crystals). As the carbamazepine crystals and the carbamazepine/nicotinamide cocrystals exhibit prism‐like and needle‐like habits, respectively, it was possible to discriminate between them with the two sensors. The mechanisms involved in the solution mediated phase transition were investigated.
Effect of Supersaturation on Polymorphs of Clopidogrel Hydrogen Sulfate in Drowning‐out Crystallization
Authors: Jim M. , Kim K.‐J. 
Published: May 2012

AbstractTo crystallize selectively forms I and II of clopidogrel hydrogen sulfate (CHS), nucleation behavior and supersaturation level were studied in mixed solvents such as formic acid/isopropanol, N,N‐dimethylformamide/isopropanol, and N‐methylpyrrolidone/isopropanol. The effect of supersaturation on induction time and nucleation rate was evaluated by comparison between nucleation mechanisms of seeded and unseeded crystallizations. Experimental results indicate that the polymorph obtained by crystallization depends on the type of seed crystals, amount of seed crystals, and seeding point. Homogeneous nucleation was desirable for the formation of form I. Form II corresponds to primary nucleation, i.e., homogeneous and heterogeneous nucleations.
Deuterium Quantification through Deuterium‐Induced Remote1H and13C NMR Shifts
Authors: Knorr Rudolf , Stephenson David S. 
Published: May 2012

AbstractPartial labeling by deuterium may be quantified through simple integrations of those1H (200 or 400 MHz) and13C (100.6 MHz) NMR resonances that are split into pairs by chemical shiftsnΔ=δ(deuterated)−δ(nondeuterated) as induced by deuterium acrossn>2 chemical bonds. The relative intensities of the two components of a pair are shown to be influenced to practically equal degrees by relaxation effects, so that a deuterium fraction may be determined from1H and13C integral pairs at more remote molecular positions under the routine conditions of fast accumulative spectral acquisition.
Large Eddy Simulation of Turbulent Reacting Mixing of Liquids in a Coaxial Jet Mixer
Authors: Walter Matthias , Kornev Nikolai , Hassel Egon 
Published: May 2012

AbstractLarge eddy simulation is used to investigate passive and reactive scalar mixing at high Reynolds Re and Schmidt Sc numbers in order to prove capability of the LES‐SGS micromixing approaches based on the eddy dissipation and DQMOM‐IEM models properly simulating liquid reacting flows. Simulations were performed for a fast neutralization reaction in a confined jet reactor. The mean profiles for passive scalar agree well with measurements. It was shown that the most contribution to the scalar variance is made by large scale motions whereas the contribution of fine scales smaller than typical inertial range scales is negligible. Thus, the existing LES models are capable of predicting the scalar variance at large Sc numbers. The results obtained for reactive transport revealed discrepancies in the determination of micromixing rate and product concentration. A special study was performed to investigate the dynamics of fine structures using locally refined box embedded into global grid. Typical statistical properties of fine structures were reproduced numerically.
A mechanistic study of agglomeration in fluidised beds at elevated pressures
Authors: Mansourpour Zahra , Mostoufi Navid , Sotudeh‐Gharebagh Rahmat 
Published: May 2012

AbstractEffect of operating pressure on the hydrodynamics of agglomerating gas–solid fluidised bed was investigated using a combination of discrete element method (DEM) for describing the movement of particles and computational fluid dynamic (CFD) for describing the flow of the gas phase. The inter‐particle cohesive force was calculated based on a time dependent model developed for solid bridging by the viscous flow. Motion of agglomerates was described by the multi‐sphere method. Fluidisation behaviour of an agglomerating bed was successfully simulated in terms of increasing the size of agglomerates. The results showed that increasing the operating pressure postpones de‐fluidisation of the bed. Since the DEM approach is a particle level simulation and study about particle–particle interactions is possible, a micro‐scale investigation in terms of cohesive force and repulsive force during agglomeration at elevated pressures was done. The micro‐scale results showed that although the number of contacts between particles was decreased by increasing operating pressure, stronger solid bridge formed between colliding particles at higher pressures. © 2012 Canadian Society for Chemical Engineering
Crystal Structure and Photoluminescence of a Tetranuclear Cadmium Complex
Authors: Shi Juan , Zhang Zunting 
Published: May 2012

AbstractA novel tetranuclear cadmium complex ([{Cd(C15H8O7S)(H2O)(DMSO)}3{Cd(C15H8O7S)(H2O)2}]·3DMSO·H2O) was obtained by the self‐assembly of Cd(II) with 5,7‐dihydroxyflavone‐6‐sulfonate. The complex was characterized by 1H NMR, IR, elemental analysis and X‐ray single‐crystal diffraction studies. It crystallizes in triclinic, space group $ P {\bar 1} $. In the complex, the chelate atoms of Cd(II) are all from oxygen. Four Cd(II) are connected via the carbonyl and 5‐hydroxyanion of four ligands and form an approximate square. Four ligands locate at two sides of the square, and two of them at the same side are almost parallel and exist aromatic π‐π stacking. Ligands on the opposite side of the square are nearly perpendicular. The result of the luminescent studies indicated that the solid of the complex shwed photoluminescent properties because of a combination of coordination, hydrogen bonding and π‐π stacking interaction in the molecule structure. The complex emits green fluorescence (λem=496 nm) when it is excited at the wavelength of 440 nm.
Synthesis, Characterization, and Highly Selective Ethylene Dimerization to 1‐Butene of [O−NX]Ni(II) Complexes
Authors: Xu Chongjie , Shen Qi , Sun Xiuli , Tang Yong 
Published: May 2012

AbstractA series of nickel(II) complexes have been synthesized and characterized. Molecular structure analysis exhibits that a square planar geometry around nickel is adopted. Upon activation with MAO, these nickel(II) complexes are efficient in catalyzing the ethylene dimerization, providing 1‐butene with an activity of up to 1.4×107 g/(mol·h·atm). The heteroatoms of the sidearm in the complexes were proved to have great impact on the activity and selectivity of 1‐butene.
Synthesis, Characterization, Optical and Electrochemical Properties of Fulleropyrrolidines Containing Trifluoromethyl Group
Authors: Li Xiangzi , Yu Rui , Fang Shu , Wei Xianwen 
Published: May 2012

AbstractFour novel [60]fullerene pyrrolidines containing trifluoromethyl (CF3) group have been synthesized via 1,3‐dipolar cycloaddition reaction, which have been characterized by UV‐Vis spectroscopy, fourier transform infrared spectroscopy, matrix‐assisted laser desorption ionization‐time of flight mass spectroscopy, and1H,13C,19F nuclear magnetic resonance spectrometer (1H NMR,13C NMR,19F NMR). Their optical and electrochemical properties have been studied, and the results show that those fulleropyrrolidines containing CF3group have good fluorescence and electrochemical properties. Compared with C60, they have negative shifts in varying degrees for half‐wave potentials, and may have potential applications for photovoltaic conversion materials since their lowest unoccupied molecular orbital (LUMO) levels are close to that of [6,6]‐phenyl‐C61‐butyric acid methyl ester.
Acyclic Palladium(II)‐N‐heterocyclic Carbene Metallacrown Ether Complexes: Synthesis, Structure and Catalytic Activity
Authors: Zhang Weixi , Zhang Xiaoqin , Luo Meiming 
Published: May 2012

AbstractNovel acyclic Pd(II)‐N‐heterocyclic carbene (NHC) metallacrown ethers 5a, 5b have been synthesized. Reaction of the imidazolium salts bearing a long polyether chain with Ag2O afforded Ag‐NHC complexes, which then reacted as carbene transfer agent with PdCl2(MeCN)2 to give the desired acyclic Pd(II)‐NHC metallacrown ether complexes 5a and 5b. The 1H NMR and 13C NMR spectra show 5a and 5b exist as mixtures of cis and trans isomers in solution. The trans isomer of 5a was characterized by X‐ray diffraction, which clearly demonstrated two pseudo‐crown ether cavities in trans‐5a. Pd(II)‐NHC complexes 5a and 5b have been shown to be highly effective in the Suzuki‐Miyaura reactions of a variety of aryl bromides in neat water without the need of inert gas protection.
Antimicrobial Aromatic Polyketides from Gorgonian‐Associated Fungus, Penicillium commune 518
Authors: Wang Junfeng , Liu Peipei , Wang Yi , Wang Hui , Li Jing , Zhuang Yibin , Zhu Weiming 
Published: May 2012

AbstractSeven new aromatic polyketides, communols A–G (1–7), were isolated and identified from the fermentation broth of Penicillium commune 518, a marine‐derived fungus associated with the Gorgonian, Muricella abnormalis. The new structures of 1–7 were determined by spectroscopic analysis and X‐ray single crystal diffraction. Among them, communol D (4) was the first example of a naturally occurring aromatic polyketide with a sulfoxide group from marine fungi. Compounds 1, 6, and 7 all showed moderate antimicrobial activities against Escherichia coli and Enterobacter aerogenes with MIC values of 4.1/16.4, 6.4/25.8, and 23.8/23.8 µmol·L−1, respectively.
Novel 1D Copper(II) Helical Chain Formed by Weak Coordination‐driven Self‐assembly: Synthesis, Structure, and Magnetic Property
Authors: Huang Wanyun , Chen Zilu , Zou Huahong , Liu Dongcheng , Liang Fupei 
Published: May 2012

AbstractA novel 1D copper(II) helical chain is constructed through the connection of tetranuclear copper(II) units [Cu4(L)(Py)4] (H8L=N,N′‐(BINOL‐3,3′‐dicarboxyl)‐disalicylhydrazide, where BINOL is 1,1′‐binaphthalenyl‐2,2′‐diol, py=pyridine) by weak coordination‐driven self‐assembly, and characterized by IR, single crystal X‐ray diffraction, thermogravimetric analysis, and X‐ray power diffraction analysis. Interestingly, the helical chains are packed in an alternating left‐(M) and right‐handed (P) chirality, the orientation of the helices was determined by the axial chirality of the ligand. The complex shows antiferromagnetic interactions between the copper centers.
Stable Water‐dispersed CdTe Nanocrystals Dependent on Stoichiometric Ratio of Cd to Te Precursor
Authors: Zhang Xurui , Wang Lixin , Guo Jia , Yang Wuli 
Published: May 2012

AbstractThe improved properties of CdTe nanocrystals (NCs) synthesized by hydrothermal method were introduced. The experimental results indicated that the NCs properties could be dramatically influenced by means of changing Cd‐to‐Te molar ratio (the molar ratio of CdCl2 and NaHTe in the precursor) of the MPA‐capped CdTe NCs. With the increase of the ratio from 2:1 to 10:1, the formation time of near‐infrared‐emitting CdTe NCs was shortened. In particular, high Cd‐to‐Te molar ratio brought about MPA‐capped CdTe NCs of superior radical oxidation‐resistance and photostability. As a result, the optimum ratio was found to be 8:1 or 10:1 in the study in order to efficiently attain stable, water‐dispersed CdTe NCs.
A Facile Synthesis of Enantiomerically Pure (R)‐6‐Arylbinols
Authors: Wang Wenling , Long Yuhua , Zou Zhifu , Yang Dingqiao 
Published: May 2012

AbstractThis work reported a convenient method for the preparation of enantiomerically pure 6‐aryl‐2,2′‐dihydroxy‐1,1′‐binaphthyl derivatives starting from the commercially available (R)‐2,2′‐hydroxy‐1,1′‐binaphthyl [(R)‐1] via bromination, hydrolysis and Suzuki cross coupling reaction. This novel synthetic method was characterized with high regioselectivity, simple operation, mild reaction conditions, and excellent yield (up to 73%). On the other hand, we synthesized the target unknown compounds, which were confirmed by IR, 1H NMR, 13C NMR, MS and elementary analysis.
Iron‐Promoted Practical One‐Pot Synthesis of 2,5‐Disubstituted Oxazoles
Authors: Chen Songhui , Bai Donghu , Shi Feng , Li Jian , Li Chunju , Jia Xueshun 
Published: May 2012

AbstractA practical one‐pot protocol for the synthesis of 2,5‐disubstituted oxazoles from 1‐aryl‐2‐nitroethanones was reported. In the presence of iron/AcOH in acetonitrile, the reaction of 1‐aryl‐2‐nitroethanones with trimethyl orthoacetate or trimethyl orthobenzoate delivered the corresponding 2,5‐disubstituted oxazoles in moderate to good yields.
Synthesis and Anti‐tumor Evaluation of Novel C‐37 Modified Derivatives of Gambogic Acid
Authors: Li Xiang , Zhang Xiaojin , Sun Haopeng , Zhang Lei , Gao Yuan , Wang Jinxin , Guo Qinglong , You Qidong 
Published: May 2012

AbstractGambogic acid (GA, 1), the most prominent representative of Garcinia natural products, has been reported to be a promising anti‐tumor agent. In order to further explore the structure‐activity relationship of GA and discover novel GA derivatives as anti‐tumor agents, 17 novel C‐37 modified derivatives of GA were synthesized and evaluated for their in vitro anti‐tumor activities against A549, HCT‐116, BGC‐823, HepG2 and MCF‐7 cancer cell lines. Among them, 11 compounds were found to be more potent than GA against some cancer cell lines. Notably, compound 8 was almost 5–10 folds more active than GA against A549 and BGC‐823 cell lines with the IC50 values of 0.12 µmol·L−1 and 0.57 µmol·L−1, respectively. Chemical modification at C‐37 position of GA by introducing of hydrophilic amines could lead to increased activity and improved drug‐like properties. These findings will enhance our understanding of the structure‐activity relationship (SAR) of GA and lead to the discovery of novel GA derivatives as potential anti‐tumor agents.
Synthesis, Characterization, Antibacterial and Antifungal Activity of Yttrium(III) Complexes Including 1,10‐Phenanthroline
Authors: Cai Mengjun , Chen Jianding , Taha Mohamed 
Published: May 2012

AbstractTwo rare metal coordination complexes of yttrium(III) including 1,10‐phenanthroline, Y(phen)2(NO3)3 and (phenH)2[Y2(pydc)3(NO3)2·6H2O] (phen=1,10‐phenanthroline, pydc=2,6‐pyridinedicarboxylate), and a proton transfer compound (phenH+)2(pydc2−) were synthesized and characterized by elemental analysis, molar conductance, infrared spectra (IR), nuclear magnetic resonance (NMR) and thermal analysis. The proposed structures of yttrium complexes were exhibited. The in vitro biological activities of the newly synthesized complexes have also been investigated against Bacillus coli, Staphylococcus aureus and Candida albicans. The results showed that yttrium(III) complexes including 1,10‐phenanthroline exhibited better antibacterial/antifungal activity than their ligands and corresponding compounds.