bluuebunny/crossref_metadata_2025_split huggingface dataset:
Boron as a Powerful Reductant: Synthesis of a Stable Boron‐Centered Radical‐Anion Radical‐Cation Pair
Authors: Bissinger Philipp , Braunschweig Holger , Damme Alexander , Hörl Christian , Krummenacher Ivo , Kupfer Thomas 
Published: November 2014

AbstractDespite the fundamental importance of radical‐anion radical‐cation pairs in single‐electron transfer (SET) reactions, such species are still very rare and transient in nature. Since diborenes have highly electron‐rich BB double bonds, which makes them strong neutral reductants, we envisaged a possible realization of a boron‐centered radical‐anion radical‐cation pair by SET from a diborene to a borole species, which are known to form stable radical anions upon one‐electron reduction. However, since the reduction potentials of all know diborenes (E1/2=−1.05/−1.55 V) were not sufficiently negative to reduce MesBC4Ph4 (E1/2=−1.69 V), a suitable diborene, IiPr⋅(iPr)BB(iPr)⋅IiPr, was tailor‐made to comply with these requirements. With a halfwave potential of E1/2=−1.95 V, this diborene ranks amongst the most powerful neutral organic reductants known and readily reacted with MesBC4Ph4 by SET to afford a stable boron‐centered radical‐anion radical‐cation pair.
Functionalization of hybrid poly(n‐isopropylacrylamide) hydrogels for Escherichia coli cell capture via adsorbed intermediate dye molecule
Authors: Gregory Jarod , Cannell Jonathon , Kofron Matthew , Yeghiazarian Lilit , Nistor Vasile 
Published: November 2014

ABSTRACTPoly(n‐isopropylacrylamide) Laponite (PNIPAM‐Lap) hybrid hydrogels, which use the synthetic clay Laponite as a crosslinker, permanently adsorb cationic laser dyes out of solution. This proof‐of‐concept expounds on this capability by adsorbing an intermediate dye molecule and using it as the foundation for successfully conjugating microbial antibodies to the surface of a PNIPAM hydrogel. The study involves using acriflavinium chloride molecules, adsorbed by a PNIPAM‐Lap hydrogel from an acriflavine laser dye solution, as an intermediate molecule to attach antibodies raised against E. coli to the hydrogel and demonstrate cell capture. Furthermore, this system exemplifies a novel biotechnological platform for greatly expanding PNIPAM hydrogels' capabilities and applicability through conjugation chemistry to surface‐bound molecules. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41557.
Preparation and characterization of MOF‐PES ultrafiltration membranes
Authors: Sotto Arcadio , Orcajo Gisela , Arsuaga Jesús María , Calleja Guillermo , Landaburu‐Aguirre Junkal 
Published: November 2014

ABSTRACTFouling is one of the main disadvantages of membrane processes. Fouling can be mitigated by incorporating inorganic particles into the membrane. Composite membranes containing the inorganic fillers show higher pore size, porosity, and hydrophilic character than the neat PES membrane, which contributes to a better permeability. In this research, PES ultrafiltration membranes are prepared using both commercial and synthesized metal‐organic framework materials (MOF) as well as ZnO particles as fillers. Among the different fillers used, MOF particles produce a better effect on the permeability of the membrane than ZnO particles. The synthesized Zn/Co‐MOF‐74‐type materials have good structural stability in the polymeric matrix and the MOF‐PES membrane maintains its performance after a series of cycles of BSA water solution. Tested MOF‐PES membrane also shows higher BSA rejections and permeate flux than the neat PES membrane, demonstrating that it is possible to enhance the flux without losing the selectivity of the membrane. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41633.
Fracture toughness of carbon fiber/polyether ether ketone composites manufactured by autoclave and laser‐assisted automated tape placement
Authors: Ray Dipa , Comer Anthony J. , Lyons John , Obande Winifred , Jones David , Higgins Ronan M. O. , McCarthy Michael A. 
Published: November 2014

ABSTRACTA comparative study is presented on the fracture toughness of carbon fiber/PEEK composites manufactured by autoclave and laser‐assisted automated tape placement (LATP). Formation of a good inter‐laminar bond is always a concern in ATP due to the short time available for intimate contact development and polymer healing, yet our double cantilever beam (DCB) tests reveal 60–80% higher Mode I fracture toughness for the LATP processed specimens than for the autoclave processed specimens. This magnitude of difference was unexpected, so specimens were further examined via differential scanning calorimetry, dynamic mechanical analysis, nano‐indentation, and scanning electron microscopy. The results indicate that the LATP process has been very effective in heating and consolidating the surface of plies, creating an excellent bond. However, it has been less effective in processing the interior of plies, where a low crystallinity and poor fiber–matrix bonding are evident. The higher fracture toughness of the LATP processed specimens is also not solely due to a better bond, but is partially due to significant plastic deformation in the interior of plies during the DCB test. The findings indicate there is still considerable scope for optimizing the laser‐assisted ATP process, before the optimum balance between strength and toughness is achieved at favorable lay‐down speeds. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41643.
Antibacterial property on Gram‐positive bacteria of polypyrrole‐coated fabrics
Authors: Varesano Alessio , Vineis Claudia , Tonetti Cinzia , Mazzuchetti Giorgio , Bobba Vittorio 
Published: November 2014

ABSTRACTAntibacterial activity against Gram‐negative bacteria of polypyrrole‐coated fabrics has been demonstrated in the past. In this work, biocidal efficacy of polypyrrole has been evaluated against Gram‐positive bacteria on textiles with different polypyrrole loading. Excellent bacterial reduction (≥99%) was found on cotton fabrics containing more than ∼9 wt % of polypyrrole. Polypyrrole loading can be greatly reduced in presence of silver. Silver‐containing fabrics used in this work alone does not guarantee a complete biocidal effect, but the addition of just 2 wt % of polypyrrole showed a bacteria reduction of 99%. Moreover, stability to different washing procedures of the antibacterial activity was evaluated. Fabrics were characterized by scanning electron microscopy, energy dispersive X‐ray analysis, and infrared spectroscopy. Stability of the coating was assessed by abrasion tests. PPy showed excellent fastness to abrasion. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41670.
Preparation and characterization of grafting styrene onto LLDPE by cyclohexane compatibilization in suspension polymerization
Authors: Meng Fanyu , Zhang Qiaoyun , Wang Guozhi , Wang Hongyan , Gao Yan 
Published: November 2014

ABSTRACTA novel method of grafting styrene onto linear low‐density polyethylene (LLDPE) by suspension polymerization was systematically evaluated. Cyclohexane as a compatibilizer was introduced to swell and activate the surface of LLDPE molecular chain for amplifying the contact point of styrene monomer with LLDPE. A series of copolymer of grafting polystyrene (PS) onto LLDPE, known as LLDPE‐g‐PS, were prepared with different ratios of cyclohexane/styrene monomer and various LLDPE dosages. FTIR and 1H NMR techniques both confirmed successful PS grafting onto the LLDPE chains. In addition, SEM images of LLDPE‐g‐PS particles showed that the cross‐section morphology becomes smooth and dense with suitable cyclohexane dosages, indicating a better compatibility between LLDPE and PS. The highest grafting efficiency was 28.4% at 10 mL/g cyclohexane and styrene monomer when 8% LLDPE was added. In these conditions, the LLDPE‐g‐PS elongation at break increased by about 30 times compared with PS. Moreover, thermal gravimetric analysis (TGA) demonstrated that LLDPE‐g‐PS possesses much higher thermal stability than pure PS. Therefore, the optimal amount of cyclohexane as compatibilizer could increase the grafting efficiency and improve the toughness of PS. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41671.
Enzymatic Synthesis of a DNA Triblock Copolymer that is Composed of Natural and Unnatural Nucleotides
Authors: Mitomo Hideyuki , Watanabe Yukie , Matsuo Yasutaka , Niikura Kenichi , Ijiro Kuniharu 
Published: November 2014

AbstractDNA molecules have come under the spotlight as potential templates for the fabrication of nanoscale products, such as molecular‐scale electronic or photonic devices. Herein, we report an enhanced approach for the synthesis of oligoblock copolymer‐type DNA by using the Klenow fragment exonuclease minus of E. coli DNA polymerase I (KF−) in a multi‐step reaction with natural and unnatural nucleotides. First, we confirmed the applicability of unnatural nucleotides with 7‐deaza‐nucleosides—which was expected because they were non‐metalized nucleotides—on the unique polymerization process known as the “strand‐slippage model”. Because the length of the DNA sequence could be controlled by tuning the reaction time, analogous to a living polymerization reaction on this process, stepwise polymerization provided DNA block copolymers with natural and unnatural bases. AFM images showed that this DNA block copolymer could be metalized sequence‐selectively. This approach could expand the utility of DNA as a template.
TP Model Transformation Via Sequentially Truncated Higher‐Order Singular Value Decomposition
Authors: Pan Junjun , Lu Linzhang 
Published: November 2014

AbstractThe sequentially truncated higher‐order singular value decomposition (ST‐HOSVD) is applied to a tensor product (TP) model transformation instead of the compact form of HOSVD (CHOSVD). The goal is to reduce computational cost in the transformation. By using the ST‐HOSVD, the TP model transformations of systems and the related algorithms are executed and the ST‐HOSVD based canonical form and the weighting functions are given. To see the effectiveness, we take a dynamic system and TORA system as numerical examples. A great reduction of complexity is seen in use of the ST‐HOSVD compared with use of the CHOSVD in TP model transformation. The approximation of the new method seems as good as the original one.
Sampled‐Data Approach to State Estimation Performance for Heterogeneous Distributed System with Fault
Authors: Chen Shun , Ho Daniel W. C. 
Published: November 2014

AbstractThis paper considers the state estimation performance for heterogeneous distributed system with fault based on sampled‐data measurement. Firstly, a performance index for distributed state estimation is proposed. Based on the sampled‐data measurement of the heterogeneous distributed system, distributed state estimators are constructed. It is proved that by analyzing the distributed state estimation error systems, the required performance index for overall state estimation can be obtained using linear matrix inequality method. Finally, a simulation example is used to illustrate the effectiveness of the proposed theoretical scheme.
Globally Stable Adaptive Tracking Control for Uncertain Strict‐Feedback Systems Based on Neural Network Approximation
Authors: Zhao Dong , Chen Weisheng , Wu Jian , Li Jing 
Published: November 2014

AbstractThis paper addresses the problem of globally stable adaptive neural tracking control for a class of strict‐feedback nonlinear systems. Compared with the existing works, the salient properties of the proposed scheme are given as follows. First, a novel switching controller is developed, which consists of a traditional adaptive neural controller and an extra robust controller to pull back the transient outside of the approximation domain. Second, only two adaptive parameters need to be tuned online, and the computational burden is considerably alleviated in practice. Third, to design the desired switching controller via the backstepping technique, a novel switching function, which has continuous derivatives up to the nth order, is constructed. It is shown that the system output converges to a small neighborhood of the reference signal and the closed‐loop system is globally stable. Finally, an example is provided to verify the effectiveness of the proposed control method.
Upregulation of Nanog and Sox‐2 genes following ectopic expression of Oct‐4 in amniotic fluid mesenchymal stem cells
Authors: Wang Kai‐Hung , Kao An‐Pei , Chang Chia‐Cheng , Lin Ta‐Chin , Kuo Tsung‐Cheng 
Published: November 2014

AbstractOctamer‐binding transcription factor 4 (Oct‐4), an important gene regulating stem cell pluripotency, is well‐known for its ability to reprogram somatic cells in vitro, either alone or in concert with other factors. The aim of this study was to assess the effect of ectopic expression of Oct human amniotic fluid stem cells. We developed a novel method for isolation of putative human amniotic fluid‐derived multipotent stem cells. These cells showing mesenchymal stem cell phenotypes (human amniotic fluid‐derived mesenchymal stem cells, hAFMSCs) were transfected with a plasmid carrying genes for Oct‐4 and the green fluorescent protein (GFP). The stably transfected cells, hAFMSCs‐Oct4/GFP, were selected by using G418 and found to express the GFP reporter gene under the control of Oct‐4 promoter. We found that hAFMSCs developed by our method possess very high self‐renewal ability (about 78 cumulative population doublings) and multilineage differentiation potency. Significantly, the hAFMSCs‐Oct4/GFP cells showed enhanced expression of the three major pluripotency genes Oct‐4, Nanog, and Sox‐2, and increased colony‐forming ability and growth rate compared with the parental hAFMSCs. We demonstrated that the ectopic expression of Oct‐4 gene in hAFMSCs with high self‐renewal ability could upregulate Nanog and Sox‐2 gene expression and enhance cell growth rate and colony‐forming efficiency. Therefore, the ectopic expression of Oct‐4 could be a strategy to develop pluripotency in hAFMSCs for clinical applications.
Cell growth behaviors of Clostridium acetobutylicum in a pervaporation membrane bioreactor for butanol fermentation
Authors: Yao Peina , Xiao Zeyi , Chen Chunyan , Li Weijia , Deng Qing 
Published: November 2014

AbstractAcetone–butanol–ethanol fermentation using Clostridium acetobutylicum was studied in the continuous and closed‐circulating fermentation (CCCF) system. The experiment lasting for 192 H was carried out by integrating fermentation with in situ pervaporation. In the entire process, the cell growth profile took place in the following two phases: the logarithmic phase during early 28 H and the linear phase from 130 to 150 H. This was a unique characteristic compared with the curve of traditional fermentation, and the fitting equations of two growth phases were obtained by Origin software according to the kinetic model of cell growth. Besides, the kinetic parameters that include the butanol yield, maximum specific growth rate, average specific formation rate, and volumetric productivity of butanol were measured as 0.19 g g−1, 0.345 H−1, 0.134 H−1 and 0.23 g L−1 H−1, respectively. The C. acetobutylicum in the CCCF system showed good adaptability and fermentation performance, and the prolonged fermentation period and high production were also the main advantages of CCCF technology.
3D bioprinting of biomimetic aortic vascular constructs with self‐supporting cells
Authors: Kucukgul Can , Ozler S. Burce , Inci Ilyas , Karakas Ezgi , Irmak Ster , Gozuacik Devrim , Taralp Alpay , Koc Bahattin 
Published: November 2014

ABSTRACTCardiovascular diseases are the leading cause of deaths throughout the world. Vascular diseases are mostly treated with autografts and blood vessel transplantations. However, traditional grafting methods have several problems including lack of suitable harvest sites, additional surgical costs for harvesting procedure, pain, infection, lack of donors, and even no substitutes at all. Recently, tissue engineering and regenerative medicine approaches are used to regenerate damaged or diseased tissues. Most of the tissue engineering investigations have been based on the cell seeding into scaffolds by providing a suitable environment for cell attachment, proliferation, and differentiation. Because of the challenges such as difficulties in seeding cells spatially, rejection, and inflammation of biomaterials used, the recent tissue engineering studies focus on scaffold‐free techniques. In this paper, the development of novel computer aided algorithms and methods are developed for 3D bioprinting of scaffold‐free biomimetic macrovascular structures. Computer model mimicking a real human aorta is generated using imaging techniques and the proposed computational algorithms. An optimized three‐dimensional bioprinting path planning are developed with the proposed self‐supported model. Mouse embryonic fibroblast (MEF) cell aggregates and support structures (hydrogels) are 3D bioprinted layer‐by‐layer according to the proposed self‐supported method to form an aortic tissue construct. Biotechnol. Bioeng. 2015;112: 811–821. © 2014 Wiley Periodicals, Inc.
Air sparging for prevention of antibody disulfide bond reduction in harvested CHO cell culture fluid
Authors: Mun Melissa , Khoo Stefanie , Do Minh Aline , Dvornicky James , Trexler‐Schmidt Melody , Kao Yung‐Hsiang , Laird Michael W. 
Published: November 2014

ABSTRACTDuring the scale‐up of several Chinese Hamster Ovary (CHO) cell monoclonal antibody production processes, significant reduction of the antibody interchain disulfide bonds was observed. The reduction was correlated with excessive mechanical cell shear during the harvest operations. These antibody reduction events resulted in failed product specifications and the subsequent loss of the drug substance batches. Several methods were recently developed to prevent antibody reduction, including modifying the cell culture media, using pre‐ and post‐harvest chemical additions to the cell culture fluid (CCF), lowering the pH, and air sparging of the harvested CCF (HCCF). The work described in this paper further explores the option of HCCF air sparging for preventing antibody reduction. Here, a small‐scale model was developed using a 3‐L bioreactor to mimic the conditions of a manufacturing‐scale harvest vessel and was subsequently employed to evaluate several air sparging strategies. In addition, these studies enabled further understanding of the relationships between cell lysis levels, oxygen consumption, and antibody reduction. Finally, the effectiveness of air sparging for several CHO cell lines and the potential impact on product quality were assessed to demonstrate that air sparging is an effective method in preventing antibody reduction. Biotechnol. Bioeng. 2015;112: 734–742. © 2014 Wiley Periodicals, Inc.
Percutaneous paravalvular leak closure for symptomatic aortic regurgitation after CoreValve transcatheter aortic valve implantation
Authors: Arri Satpal S. , Poliacikova P. , Hildick‐Smith D. 
Published: November 2014

ObjectivesWe present a case series of five patients in whom percutaneous paravalvular leak closure with the AVP4 device has been undertaken for symptomatic aortic regurgitation after CoreValve TAVI.BackgroundSignificant post‐procedure aortic regurgitation (AR) is often difficult to assess, and is an important predictor of adverse outcome following TAVI. Paravalvular leak closure is an established procedure for surgical aortic prostheses, and has been undertaken for Edwards TAVIs, but has not been described for closure of CoreValve paravalvular leaks.Methods and ResultsFive patients were treated (mean age 81 ± 4 years) with residual grade 3–4 AR following placement of a single CoreValve (n = 2), double CoreValve (n = 2) or CoreValve within a bioprosthetic AVR (n = 1). The mean time post TAVI implantation was 308 ± 269 days. All patients were symptomatic with persistent NYHA Grade III dyspnoea. 6 devices were deployed successfully, with mean procedure time of 109 ± 23 min. There were no procedural complications and all patients were discharged home by Day 2. Residual AR after treatment was grade 0 (n = 2), grade 1 (n = 1), grade 2 (n = 1) and grade 3 (n = 1). Symptomatic improvement was noted in all 4 patients who have been reviewed in clinic since.ConclusionsThis small series demonstrates the feasibility of paravalvular leak closure with the CoreValve TAVI, despite the adverse aortic lattice. The AVP4 device is ideally suited to this situation as it will pass through a 0.038' lumen and can therefore be delivered down standard diagnostic catheters. © 2014 Wiley Periodicals, Inc.
Development of Unique Xanthene–Cyanine Fused Near‐Infrared Fluorescent Fluorophores with Superior Chemical Stability for Biological Fluorescence Imaging
Authors: Chen Hua , Lin Weiying , Cui Haijun , Jiang Wenqing 
Published: November 2014

AbstractThe development of near‐infrared (NIR) functional fluorescent dyes has gained increasing attention over the last few decades. Herein, we describe the development of a unique type of xanthene–cyanine fused NIR fluorophores, XC dyes, formed by reacting chloro‐substituted cyanine with resorcin or its analogues under anhydrous conditions. XC dyes are a hybrid of cyanine and xanthene. The preliminary mechanistic studies indicate that the formation of XC compounds likely includes a sequence of cyclization and oxidation. XC dyes have absorption and emission in the NIR region, and their fluorescence properties can be controlled by modifications of the key hydroxyl and amine groups. The novel XC NIR dyes are advantageous over previously developed merocyanine dyes NIR dyes in their chemical stability against strong nucleophiles. Quantum chemical calculations reveal that the distinct properties of XC and HD dyes can be attributed to their structural differences. By taking advantage of the superior properties of XC dyes, we have further constructed a new NIR fluorescent probe, XC‐H2S, which is capable of monitoring both the concentration‐ and time‐dependent variations of H2S in living animals, highlighting the value of XC NIR dyes. We expect that the unique XC NIR dyes developed herein will find broader applications than HD NIR dyes as fluorescent platforms for the development of a wide variety of NIR fluorescent probes, in particular, those suitable for targets of interest that have strong nucleophilic character.