bluuebunny/crossref_metadata_2025 huggingface dataset:
Stereocontrolled Synthesis of 1,5‐Stereogenic Centers through Three‐Carbon Homologation of Boronic Esters
Authors: Unsworth Phillip J. , Leonori Daniele , Aggarwal Varinder K.
Published: July 2014

Allylic pinacol boronic esters are stable toward 1,3‐borotropic rearrangement. We developed a PdII‐mediated isomerization process that gives di‐ or trisubstituted allylic boronic esters with high E selectivity. The combination of this method with lithiation–borylation enables the synthesis of carbon chains that bear 1,5‐stereogenic centers. The utility of this method has been demonstrated in a formal synthesis of (+)‐jasplakinolide.
Orientation‐Controlled Single‐Molecule Junctions
Authors: Afsari Sepideh , Li Zhihai , Borguet Eric
Published: July 2014

The conductivity of a single aromatic ring, perpendicular to its plane, is determined using a new strategy under ambient conditions and at room temperature by a combination of molecular assembly, scanning tunneling microscopy (STM) imaging, and STM break junction (STM‐BJ) techniques. The construction of such molecular junctions exploits the formation of highly ordered structures of flat‐oriented mesitylene molecules on Au(111) to enable direct tip/π contacts, a result that is not possible by conventional methods. The measured conductance of Au/π/Au junction is about 0.1 Go , two orders of magnitude higher than the conductance of phenyl rings connected to the electrodes by standard anchoring groups. Our experiments suggest that long‐range ordered structures, which hold the aromatic ring in place and parallel to the surface, are essential to increase probability of the formation of orientation‐controlled molecular junctions.
Ligand Modification Transforms a Catalase Mimic into a Water Oxidation Catalyst
Authors: Lee Wei‐Tsung , Muñoz Salvador B. , Dickie Diane A. , Smith Jeremy M.
Published: July 2014

The catalytic reactivity of the high‐spin MnII pyridinophane complexes [(Py2NR2)Mn(H2O)2]2+ (R=H, Me, tBu) toward O2 formation is reported. With small macrocycle N‐substituents (R=H, Me), the complexes catalytically disproportionate H2O2 in aqueous solution; with a bulky substituent (R=tBu), this catalytic reaction is shut down, but the complex becomes active for aqueous electrocatalytic H2O oxidation. Control experiments are in support of a homogeneous molecular catalyst and preliminary mechanistic studies suggest that the catalyst is mononuclear. This ligand‐controlled switch in catalytic reactivity has implications for the design of new manganese‐based water oxidation catalysts.
Synthesis of the Heparin‐Based Anticoagulant Drug Fondaparinux
Authors: Chang Cheng‐Hsiu , Lico Larry S. , Huang Teng‐Yi , Lin Shu‐Yi , Chang Chi‐Liang , Arco Susan D. , Hung Shang‐Cheng
Published: July 2014

Fondaparinux, a synthetic pentasaccharide based on the heparin antithrombin‐binding domain, is an approved clinical anticoagulant. Although it is a better and safer alternative to pharmaceutical heparins in many cases, its high cost, which results from the difficult and tedious synthesis, is a deterrent for its widespread use. The chemical synthesis of fondaparinux was achieved in an efficient and concise manner from commercially available D‐glucosamine, diacetone α‐D‐glucose, and penta‐O‐acetyl‐D‐glucose. The method involves suitably functionalized building blocks that are readily accessible and employs shared intermediates and a series of one‐pot reactions that considerably reduce the synthetic effort and improve the yield.
Synthesis of Densely Phosphorylated Bis‐1,5‐Diphospho‐myo‐Inositol Tetrakisphosphate and its Enantiomer by Bidirectional P‐Anhydride Formation
Authors: Capolicchio Samanta , Wang Huanchen , Thakor Divyeshsinh T. , Shears Stephen B. , Jessen Henning J.
Published: July 2014

The ubiquitous mammalian signaling molecule bis‐diphosphoinositol tetrakisphosphate (1,5‐(PP)2‐myo‐InsP4, or InsP8) displays the most congested three‐dimensional array of phosphate groups found in nature. The high charge density, the accumulation of unstable P‐anhydrides and P‐esters, the lack of UV absorbance, and low levels of optical rotation constitute severe obstacles to its synthesis, characterization, and purification. Herein, we describe the first procedure for the synthesis of enantiopure 1,5‐(PP)2‐myo‐InsP4 and 3,5‐(PP)2‐myo‐InsP4 utilizing a C2‐symmetric P‐amidite for desymmetrization and concomitant phosphitylation followed by a one‐pot bidirectional P‐anhydride‐forming reaction that combines sixteen chemical transformations with high efficiency. The configuration of these materials is unambiguously shown by subsequent X‐ray analyses of both enantiomers after being individually soaked into crystals of the kinase domain of human diphosphoinositol pentakisphosphate kinase 2.
High‐Performance Hole‐Extraction Layer of Sol–Gel‐Processed NiO Nanocrystals for Inverted Planar Perovskite Solar Cells
Authors: Zhu Zonglong , Bai Yang , Zhang Teng , Liu Zhike , Long Xia , Wei Zhanhua , Wang Zilong , Zhang Lixia , Wang Jiannong , Yan Feng , Yang Shihe
Published: July 2014

Hybrid organic/inorganic perovskite solar cells have been rapidly evolving with spectacular successes in both nanostructured and thin‐film versions. Herein, we report the use of a simple sol–gel‐processed NiO nanocrystal (NC) layer as the hole‐transport layer in an inverted perovskite solar cell. The thin NiO NC film with a faceted and corrugated surface enabled the formation of a continuous and compact layer of well‐crystallized CH3NH3PbI3 in a two‐step solution process. The hole‐extraction and ‐transport capabilities of this film interfaced with the CH3NH3PbI3 film were higher than those of organic PEDOT:PSS layers. The cell with a NiO NC film with a thickness of 30–40 nm exhibited the best performance, as a thinner layer led to a higher leakage current, whereas a thicker layer resulted in a higher series resistance. With the NiO film, we observed a cell efficiency of 9.11 %, which is by far the highest reported for planar perovskite solar cells based on an inorganic hole‐extracting layer.
Synthesis and Duplex‐Stabilizing Properties of Fluorinated N‐Methanocarbathymidine Analogues Locked in the C3′‐endo Conformation
Authors: Jung Michael E. , Dwight Timothy A. , Vigant Frederic , Østergaard Michael E. , Swayze Eric E. , Seth Punit P.
Published: July 2014

The efficient synthesis, antiviral activity, and duplex‐stabilizing properties of both isomers of the 2′‐fluoro analogue of Northern methanocarbathymidine (N‐MCT), 2 and 3, are reported. We show that 2′‐F incorporation on the N‐MCT scaffold has a strong stabilizing effect on duplex thermal stability.
Langmuir Analysis of Nanoparticle Polyvalency in DNA‐Mediated Adsorption
Authors: O'Brien Matthew N. , Radha Boya , Brown Keith A. , Jones Matthew R. , Mirkin Chad A.
Published: July 2014

Many nanoparticle adsorption processes are dictated by the collective interactions of surface‐bound ligands. These adsorption processes define how nanoparticles interact with biological systems and enable the assembly of nanoparticle‐based materials and devices. Herein, we present an approach for quantifying nanoparticle adsorption thermodynamics in a manner that satisfies the assumptions of the Langmuir model. Using this approach, we study the DNA‐mediated adsorption of polyvalent anisotropic nanoparticles on surfaces and explore how deviations from model assumptions influence adsorption thermodynamics. Importantly, when combined with a solution‐based van’t Hoff analysis, we find that polyvalency plays a more important role as the individual interactions become weaker. Furthermore, we find that the free energy of anisotropic nanoparticle adsorption is consistent across multiple shapes and sizes of nanoparticles based on the surface area of the interacting facet.
CXCR4‐Targeted and MMP‐Responsive Iron Oxide Nanoparticles for Enhanced Magnetic Resonance Imaging
Authors: Gallo Juan , Kamaly Nazila , Lavdas Ioannis , Stevens Elizabeth , Nguyen Quang‐De , Wylezinska‐Arridge Marzena , Aboagye Eric O. , Long Nicholas J.
Published: July 2014

MRI offers high spatial resolution with excellent tissue penetration but it has limited sensitivity and the commonly administered contrast agents lack specificity. In this study, two sets of iron oxide nanoparticles (IONPs) were synthesized that were designed to selectively undergo copper‐free click conjugation upon sensing of matrix metalloproteinase (MMP) enzymes, thereby leading to a self‐assembled superparamagnetic nanocluster network with T2 signal enhancement properties. For this purpose, IONPs with bioorthogonal azide and alkyne surfaces masked by polyethylene glycol (PEG) layers tethered to CXCR4‐targeted peptide ligands were synthesized and characterized. The IONPs were tested in vitro and T2 signal enhancements of around 160 % were measured when the IONPs were incubated with cells expressing MMP2/9 and CXCR4. Simultaneous systemic administration of the bioorthogonal IONPs in tumor‐bearing mice demonstrated the signal‐enhancing ability of these ‘smart’ self‐assembling nanomaterials.
A new strategy for plasticizing and stabilization of PVC mixtures
Authors: Kalousková Radka , Fartáková Helena , Malinová Lenka , Brožek Jiří
Published: July 2014

This study was undertaken to examine possible use of classic tetravalent tin‐based heat stabilizers for the preparation of a polymer plasticizer: poly(ε‐caprolactone) (PCL) and simultaneous stabilization of PVC in PVC/PCL mixtures. PCL was prepared from ε‐caprolactone (CL) by polymerization initiated by tin‐containing organic compounds and successfully used to simultaneously plasticize and stabilize PVC. Moreover, conditions under which the polymerization of CL took place directly in situ during PVC/CL mixture processing were found. The procedure yielded homogeneous plasticized PVC/PCL mixtures, which were stable and contained >90% of the original monomer content. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41066.
Synthesis and In vitro cytotoxicity of poly(ethylene glycol)–epothilone B conjugates
Authors: Zhang Haiyan , Wang Kun , Cheng Xiaochen , Lu Yuxin , Zhang Qinglin
Published: July 2014

Natural epothilone B (EPOB) is currently in clinical trials for treatment of advanced cancers. In this study, two poly(ethylene glycol) (PEG)–EPOB conjugates were synthesized with carbodiimide chemistry with linear PEG Methoxy‐PEG‐Carboxymethy(mPEG‐COOH) with different molecular weights (5 and 20 kDa). The products were confirmed by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectroscopy and 1H‐NMR, which showed that PEGylation only took place at the 7‐OH site of EPOB. The solubilities of PEG5K–EPOB the conjugate of mPEG‐COOH (MW 5,000) and epothilone B and PEG20K–EPOB the conjugate of mPEG‐COOH (MW 20,000) and epothilone B were determined to be 4.93 × 10−2 and 1.58 × 10−2 mmol/mL; this showed improvements of 35 and 11 times, respectively, over that of free EPOB (1.4 × 10−3 mmol/mL). Moreover, the conjugates were more stable than that of free EPOB in plasma. The cytotoxicity of conjugates was evaluated on human breast cancer MCF‐7 cells with an 3‐(4,5)‐dimethylthiahiazo (‐z‐y1)‐3,5‐di‐ phenytetrazoliumromide(MTT) based assay. The half maximal inhibitory concentration of a substance(IC50) values of EPOB, PEG5K–EPOB, and PEG20K–EPOB were 6.0 × 10−4, 0.57, and 8.4 × 10−3 μM, respectively. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41123.
Nanocomposites based on MWCNT and polystyrene, styrene‐acrylonitrile copolymer, or polymethylmethacrylate, obtained by miniemulsion polymerization
Authors: Donescu Dan , Corobea Mihai Cosmin , Petcu Cristian , Spataru Catalin Ilie , Ghiurea Marius , Somoghi Raluca , Gabor Raluca , Thomassin Jean‐Michel , Alexandre Michaël , Jerome Christine
Published: July 2014

Free radical miniemulsion polymerization of styrene (St), St/acrylonitrile 3 : 1 mixture or methylmethacrylate in the presence of multiwalled carbon nanotubes (MWCNT) was proven as a convenient way to obtain homogenous hybrids with perspectives in associated applications like foams specialties materials. Miniemulsion polymerization was viable up to 2% wt. MWCNT to monomer, without agglomerations. The grafting on MWCNT during the polymerization occurs without the need for supplementary functionalization and the polymer grafted nanotubes showed stable dispersions in the polymer solvent. Monomer polarity affected the grafting ability during the polymerization process. The nanocomposites obtained after purification and drying were used in foaming process. MWCNT presence in the related nanocomposites decreased the pore sizes in foam‐like materials (for all three different matrices). At 1 wt % MWCNT content, low density (< 0.3 g/cm3), low pore size (< 10 μm) and high cell density (>109 cell/cm3) were achieved. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41148.
Mechanical and barrier properties of thermoplastic whey protein isolate/ethylene vinyl acetate blends
Authors: Schmid Markus , Müller Kerstin , Sängerlaub Sven , Stäbler Andreas , Starck Vanessa , Ecker Felix , Noller Klaus
Published: July 2014

Crude oil is becoming scarcer and more expensive, resulting in alternative biobased or partially biobased materials gaining importance in the field of plastic packaging and encouraging the development of naturally derived, protein‐based plastics (Endres, 2009; Jones and McClements, Compreh. Rev. Food Sci. Food Safety 2010, 9, 374; Khwaldia et al., Compreh. Rev. Food Sci. Food Safety 2010, 9, 374). A strategy to improve extrusion processing behavior of proteins is the blending with other polymers. In this study ethylene vinyl acetate (EVA) was used for such purpose. The aim of this study was to determine the properties of blends of thermoplastic whey protein (TPP) and ethylene vinyl acetate (EVA). Mechanical and barrier properties were tested. Blends of differing TPP/EVA ratio were produced and extruded into flat films. Morphological analysis of the blends shows immiscibility of the TPP and EVA, greatly influencing the mechanical properties. Young's modulus measurements shows the values approached that of pure EVA with increasing EVA ratios. At values of about 21 MPa, corresponding to EVA ratios of 30% (w/w) and above, continuous extrusion including material take‐off was possible. At higher whey protein ratios in the blends the water vapor transmission rate increased, i.e., the higher water vapor transmission rate of whey protein compared with EVA dominated this property. This study showed that whey proteins can be utilized for extrusion by blending with EVA. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41172.
Cell morphology, bubbles migration, and flexural properties of non‐uniform epoxy foams using chemical foaming agent
Authors: Wang Lijun , Yang Xu , Jiang Tuanhui , Zhang Chun , He Li
Published: July 2014

Epoxy foams with different densities and microstructures were prepared by changing the process parameters including the foaming temperature, chemical foaming agent (CFA) content and precuring extent. The microstructure of foams reveals a smaller cell size, higher cell density, and more homogeneous distribution of cells at higher precuring extent. However, the cell size and distribution are not affected by the foaming temperature and CFA content without precuring process. In addition, the bubbles migration, which resulted in non‐uniform cell density distribution, was promoted by increasing the foaming temperature and depressed by increasing the CFA content and precuring extent. The flexural properties of the non‐uniform epoxy foams were also studied. Results showed that the flexural modulus was related to the cell morphology, while the flexural strength was affected by both the cell morphology and the position of the specimens during test. It was also found that the relative flexural modulus and strength exhibited a power‐law dependence with respect to the relative density. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41175.
Fabrication of the self‐reinforced composites using co‐extrusion technique
Authors: Andrzejewski Jacek , Szostak Marek , Barczewski Mateusz , Krasucki Janusz , Sterzynski Tomasz
Published: July 2014

The results of this work relate to the use of co‐extrusion technology in the preparation of monocomposite pellets. The low‐melting polypropylene copolymer was used as a matrix material. The high strength polypropylene fibers were used as a fibrous reinforcement. Research confirms the possibility to produce the pellets with fibrous structure. The prepared composite material in the form of pellets was processed and shaped using the injection molding technology. Obtained samples were subjected to mechanical testing in the static tensile test and dynamic mechanical analysis. Research complements microscopic observation of scanning electron microscopy. The measurement results confirm the reinforcing effect of the fibers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41180.
Effect of poly(ethylene glycol) on the properties and foaming behavior of macroporous poly(lactic acid)/sodium chloride scaffold
Authors: Chen Bin‐Yi , Wang Yuan‐Sheng , Mi Hao‐Yang , Yu Peng , Kuang Tai‐Rong , Peng Xiang‐Fang , Wen Jing‐Song
Published: July 2014

In this study, we prepared poly(lactic acid) (PLA)/poly(ethylene glycol) (PEG)/sodium chloride (NaCl) blends by melt blending with a triple‐screw dynamic extruder. The effects of PEG on the thermal property, mechanical property, and morphology of blends were investigated in detail. It was found that the incorporation of PEG and NaCl significantly improved the crystallization rate, elongation at break, surface adhesion, and reduced viscoelasticity of PLA. The blends were further batch‐foamed at different temperatures with supercritical carbon dioxide to study the foaming properties. The results of PLA/PEG/NaCl (50 : 10 : 40 wt %) composites after foaming and particle leaching revealed that an interconnected bimodal porous scaffold with the highest porosity of 89% could be achieved. Furthermore, the addition of PEG can significantly reduce the water contact angle so as to enhance the wetting ability of the scaffolds. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41181.
Meticulous analysis and consequences of microstructure changes on melt rheology and dynamic viscoelasticity of thermoplastic vulcanizates upon reprocessing
Authors: Dey Pranab , Naskar Kinsuk , Nando Golok B. , Dash Biswaranjan , Nair Sujith , Unnikrishnan G.
Published: July 2014

Thermoplastic vulcanizates (TPVs), which are a special class of elastomer alloy, prepared by dynamic vulcanization possess unique morphology of finely dispersed micron‐size cross‐linked elastomeric particles in a continuous thermoplastic matrix. The present study investigates the microstructure formation of elastomeric phase and its associated morphological changes during reprocessing of TPVs based on poly[styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene] triblock co‐polymer (S‐EB‐S) and solution polymerized styrene butadiene elastomer (S‐SBR) by scanning electron microscopy and atomic force microscopy. Semi‐efficient and efficient sulfur‐based curing systems have been adopted to cure the elastomeric phase and a comparative study has been made to demonstrate and explain the effect of reprocessing on the melt rheology and dynamic viscoelasticity of the TPVs. The present work also provides a better insight and guidance to control the microstructure of the cross‐linked elastomeric phase to prepare selectively co‐continuous or dispersed phase morphology. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41182.
The influence of dispersants that contain polyethylene oxide groups on the electrical resistivity of silver paste
Authors: Chiang Tzu Hsuan , Chen Yi‐Fu , Lin Ya Chun , Chen Emi Yun
Published: July 2014

This study investigated the effects of dispersants on the electrical resistivity of silver pastes. The dispersants in the polyoxy ethylene‐p‐(1,1,3,3‐tetramethylbutyl) phenyl ethers system contain several polyethylene oxide (PEO) groups (m), which are affect the viscosity and electrical resistivity of the silver pastes. The morphologies of the cured silver pastes for different dispersants and different content were obtained by scanning electronic microscopy. In this study, octylphenol ethylene oxide condensate, poly(oxyethylene) isooctylphenyl ether (X‐100, the number of PEO groups was m = 9.5) has excellent ability to disperse silver particles. A loading of 75 wt % of silver powder was used to prepare silver paste that contained 0.8 wt % of X‐100. This paste had the lowest viscosity and the lowest electrical resistivity of cured silver paste on the indium tin oxide (ITO) film and ITO glass, i.e., 5.52 × 10−5 and 6.82 × 10−5 Ω cm. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41183.
Impact of salts on polyacrylamide hydrolysis and gelation: New insights
Authors: El Karsani Khalid S. M. , Al‐Muntasheri Ghaithan A. , Sultan Abdullah S. , Hussein Ibnelwaleed A.
Published: July 2014

Polyacrylamide (PAM) and its derivatives are the most commonly used polymers in the preparation of polymeric gels for water control in petroleum reservoirs. This study involved the use of polyethylenimine (PEI) as a crosslinker for PAM. In this study, we investigated PAM alkaline hydrolysis at high temperatures. The effects of salts [sodium chloride (NaCl) and ammonium chloride (NH4Cl)] on the degree of hydrolysis (DH) of PAM were investigated. These salts were used as retarders to elongate the gelation time of the PAM/PEI system. The data obtained from 13C‐NMR was used to understand the retardation mechanisms by salts. We found that NH4Cl accelerated the extent of hydrolysis more in comparison with NaCl. Moreover, the apparent viscosity of the hydrolyzed samples was measured. PAM hydrolysis in the presence of NH4Cl resulted in a lower solution viscosity than that in the presence of NaCl. Therefore, NH4Cl was more effective in shielding negative charges on the carboxylate groups of the partially hydrolyzed polyacrylamide (PHPA) chain. NaCl and NH4Cl were compatible with the PHPA/PEI system, but sodium carbonate showed a white precipitate. In addition, high‐temperature/high‐pressure elastic modulus data were reported for the first time for this system. Differential scanning calorimetry was coupled with rheology to explain the PAM/PEI crosslinking in the presence of salts. Models were developed to assess the impact of the salts on the PAM DH and the induction period before gelation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41185.
Biomineralized hyaluronic acid/poly(vinylphosphonic acid) hydrogel for bone tissue regeneration
Authors: Kim So Yeon , Park Jeong‐Sook
Published: July 2014

Novel biomineralized hydrogels composed of hyaluronic acid (HA) and vinyl phosphonic acid (VPAc) were designed with the aim of developing a biomimetic hydrogel system to improve bone regeneration by local delivery of a protein drug including bone morphogenetic proteins. We synthesized crosslinked hydrogels composed of methacrylated HA and poly(VPAc) [P(VPAc)], which serves as a binding site for calcium ions during the mineralization process. The HA/P(VPAc) hydrogels were biomineralized by a urea‐mediation method to create functional polymer hydrogels that can deliver the protein drug and mimic the bone extracellular matrix. The water content of the hydrogels was influenced by the HA/P(VPAc) composition, crosslinking density, biomineralization, and ionic strength of the swelling media. All HA/P(VPAc) hydrogels maintained more than 84% water content. Enzymatic degradation of HA/P(VPAc) hydrogels was dependent on the concentration of hyaluronidase and the crosslinking density of the polymer network within the hydrogel. In addition, the release behavior of bovine serum albumin from the HA/PVPAc hydrogels was mainly influenced by the drug loading content, water content, and biomineralization of the hydrogels. In a cytotoxicity study, the HA/P(VPAc) and biomineralized HA/P(VPAc) hydrogels did not significantly affect cell viability. These results suggest that biomineralized HA/P(VPAc) hydrogels can be tailored to create a biomimetic hydrogel system that promotes bone tissue repair and regeneration by local delivery of protein drugs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41194.
Role of water as a coporogen in the synthesis of mesoporous poly(divinylbenzenes)
Authors: Hanková Libuše , Holub Ladislav , Meng Xiangju , Xiao Feng‐Shou , Jeřábek Karel
Published: July 2014

The morphology of mesoporous poly(divinylbenzenes) prepared under so called “hydrothermal” conditions and with the monomers diluted in 10 times as much porogen solvent (tetrahydrofuran with 0–20% water) was studied in both dry and swollen states, with nitrogen adsorption/desorption and inverse steric exclusion chromatography, respectively. It was found that the pore volume in the polymer examined just after preparation corresponded to the volume of the porogen used. Such a high porosity can be explained only on the basis of pore formation through microsyneresis rather than the macrosyneresis mechanism that is common in the synthesis of conventional porous polymer materials. Naturally, drying induces a pore collapse and the addition of water to the porogen influences the ability of the polymer to regain the original pore volume by reswelling in tetrahydrofuran. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41198.
CLONING AND EXPRESSION ANALYSIS OF G‐PROTEIN Gαq SUBUNIT AND Gβ1 SUBUNIT FROM Bemisia tabaci GENNADIUS (HOMOPTERA: ALEYRODIDAE)
Authors: Tu Hongtao , Qin Yuchuan
Published: July 2014

The heterotrimeric G proteins play an essential role in a wide variety of signal transduction pathways, mediating the process of chemical signals from the environment in all higher eukaryotic organisms. In this article, two G‐protein subunit genes encoding Gαq and Gβ1 were cloned from Bemisia tabaci Gennadius. The full‐length cDNA sequence of BtGαq consisted of 2,336 bp with an ORF of 1,062 bp encoding 353 amino acids and BtGβ1 had a full length of 1,942 bp with an ORF of 1,023 nucleotides encoding 340 amino acids. The amino acid sequences of BtGαq and BtGβ1 from B. tabaci B biotype were identical to those from the Q biotype. Phylogenetic analysis identified G protein α and β subunit families from insects based on their amino acid sequences. The expression patterns of BtGαq and BtGβ1 at different development stages and in different body regions were analyzed by real‐time quantitative PCR and Western blot. The results show that BtGαq and BtGβ1 are neither developmental stage‐specific nor tissue‐specific. The transcript levels of BtGαq in the B biotype are similar to that in the Q biotype, the transcript levels of BtGβ1 at egg, first instar and pupae in B biotype were significantly higher than that in Q biotype. The transcript levels of BtGαq and BtGβ1 in the head were significantly higher than those in thorax and abdomen indicating that they are involved in nervous system and sensory functions.
Understanding engagement with the privacy domain through design research
Authors: Vasalou Asimina , Oostveen Anne‐Marie , Bowers Chris , Beale Russell
Published: July 2014

This paper reports findings from participatory design research aimed at uncovering how technological interventions can engage users in the domain of privacy. Our work was undertaken in the context of a new design concept, “Privacy Trends”, whose aspiration is to foster technology users' digital literacy regarding ongoing privacy risks and elucidate how such risks fit within existing social, organizational, and political systems, leading to a longer‐term privacy concern. Our study reveals 2 challenges for privacy intervention design: the need to develop technology users' intrinsic motivations with the privacy domain and the importance of framing the concept of privacy within users' interests. Setting our study within a design context enables us to identify 4 design opportunities for fostering engagement with the privacy domain through technology design.
Testing for the fairness and predictive validity of research funding decisions: A multilevel multiple imputation for missing data approach using ex‐ante and ex‐post peer evaluation data from the Austrian science fund
Authors: Mutz Rüdiger , Bornmann Lutz , Daniel Hans‐Dieter
Published: July 2014

It is essential for research funding organizations to ensure both the validity and fairness of the grant approval procedure. The ex‐ante peer evaluation (EXANTE) of N = 8,496 grant applications submitted to the Austrian Science Fund from 1999 to 2009 was statistically analyzed. For 1,689 funded research projects an ex‐post peer evaluation (EXPOST) was also available; for the rest of the grant applications a multilevel missing data imputation approach was used to consider verification bias for the first time in peer‐review research. Without imputation, the predictive validity of EXANTE was low (r = .26) but underestimated due to verification bias, and with imputation it was r = .49. That is, the decision‐making procedure is capable of selecting the best research proposals for funding. In the EXANTE there were several potential biases (e.g., gender). With respect to the EXPOST there was only one real bias (discipline‐specific and year‐specific differential prediction). The novelty of this contribution is, first, the combining of theoretical concepts of validity and fairness with a missing data imputation approach to correct for verification bias and, second, multilevel modeling to test peer review‐based funding decisions for both validity and fairness in terms of potential and real biases.
Simple and robust monitoring of ethanol fermentations by capillary electrophoresis
Authors: Oliver James D. , Sutton Adam T. , Karu Naama , Phillips Michael , Markham Julie , Peiris Paul , Hilder Emily F. , Castignolles Patrice
Published: July 2014

Free‐solution capillary electrophoresis (CE), or capillary zone electrophoresis, with direct UV detection was used for the first time for the determination of mono‐ and disaccharides, sugar alcohols, and ethanol in fermentation broths. Sample preparation proved to be minimal: no derivatization or specific sample purification was needed. The CE conditions can be adapted to the type of fermentation by simply altering the background electrolyte (BGE). KOH (130 mM) or NaOH (130 mM) as the BGE led to the fastest analysis time when monitoring simple fermentations. A mixture of 65 mM NaOH and 65 mM LiOH led to a 19% improvement in resolution for a complex mixture of carbohydrates. Quantification of a simple carbohydrate fermentation by CE showed values in close agreement with that of high‐performance anion exchange chromatography and high‐performance liquid chromatography (HPLC) on a cation exchange resin. For complex fermentations, quantification of carbohydrates by HPLC and CE led to similar results, whereas CE requires an injection volume of only 10–20 nL. Analysis of an ethanol fermentation of hydrolyzed plant fiber demonstrated the robustness of the separation and detection of carbohydrates, as well as ethanol. Ethanol determination is achieved by coupling the CE method to pressure mobilization, using the same instrument and the same sample.
Unraveling recombination rate evolution using ancestral recombination maps
Authors: Munch Kasper , Schierup Mikkel H. , Mailund Thomas
Published: July 2014

Recombination maps of ancestral species can be constructed from comparative analyses of genomes from closely related species, exemplified by a recently published map of the human‐chimpanzee ancestor. Such maps resolve differences in recombination rate between species into changes along individual branches in the speciation tree, and allow identification of associated changes in the genomic sequences. We describe how coalescent hidden Markov models are able to call individual recombination events in ancestral species through inference of incomplete lineage sorting along a genomic alignment. In the great apes, speciation events are sufficiently close in time that a map can be inferred for the ancestral species at each internal branch ‐ allowing evolution of recombination rate to be tracked over evolutionary time scales from speciation event to speciation event. We see this approach as a way of characterizing the evolution of recombination rate and the genomic properties that influence it.
Luminescence and spectroscopic studies of halosulfate phosphors: a review
Authors: Gedam S. C. , Thakre P. S. , Dhoble S. J.
Published: July 2014

This review discusses the photoluminescence (PL) characteristics of halosulfate phosphors developed by us. Halosulfate phosphors KCaSO4Cl:X,Y (X = Eu or Ce; Y = Dy or Mn) and Na6(SO4)2FCl (doped with Dy, Ce or Eu) were prepared using a solid‐state diffusion method. The mechanism of energy transfer from Eu2+→Dy3+, Ce3+→Dy3+ and Ce3+→Mn2+ has also been studied. Dy3+ emission in the host at 475 and 570 nm is observed due to 4F9/2→6H15/2 and 4F9/2→6H13/2 transition, whereas the PL emission spectra of Na6(SO4)2FCl:Ce phosphor shows Ce3+ emission at 322 nm due to 5d→4f transition of the Ce3+ ion. The main property of KCaSO4Cl is its very high sensitivity, particularly when doped by Dy, Mn or Pb activators. This review also discusses the PL characteristics of some new phosphors such as LiMgSO4F, Na6Pb4(SO4)6Cl2, Na21Mg(SO4)10Cl3 and Na15(SO4)5F4Cl. Copyright © 2014 John Wiley & Sons, Ltd.
New evidence on treatments for varicose veins
Authors: Campbell B
Published: July 2014

Still inconclusive
Treating cell culture media with UV irradiation against adventitious agents: Minimal impact on CHO performance
Authors: Yen Sandi , Sokolenko Stanislav , Manocha Bhavik , Patras Ankit , Daynouri‐Pancino Farnaz , Blondeel Eric J.M. , Sasges Michael , Aucoin Marc G.
Published: July 2014

Sterility of cell culture media is an important concern in biotherapeutic processing. In large scale biotherapeutic production, a unit contamination of cell culture media can have costly effects. Ultraviolet (UV) irradiation is a sterilization method effective against bacteria and viruses while being non‐thermal and non‐adulterating in its mechanism of action. This makes UV irradiation attractive for use in sterilization of cell culture media. The objective of this study was to evaluate the effect of UV irradiation of cell culture media in terms of chemical composition and the ability to grow cell cultures in the treated media. The results showed that UV irradiation of commercial cell culture media at relevant disinfection doses impacted the chemical composition of the media with respect to several carboxylic acids, and to a minimal extent, amino acids. The cumulative effect of these changes, however, did not negatively influence the ability to culture Chinese Hamster Ovary cells, as evaluated by cell viability, growth rate, and protein titer measurements in simple batch growth compared with the same cells cultured in control media exposed to visible light. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1190–1195, 2014
Synchronized mammalian cell culture: Part I—A physical strategy for synchronized cultivation under physiological conditions
Authors: Barradas Oscar Platas , Jandt Uwe , Becker Max , Bahnemann Janina , Pörtner Ralf , Zeng An‐Ping
Published: July 2014

Conventional analysis and optimization procedures of mammalian cell culture processes mostly treat the culture as a homogeneous population. Hence, the focus is on cell physiology and metabolism, cell line development, and process control strategy. Impact on cultivations caused by potential variations in cellular properties between different subpopulations, however, has not yet been evaluated systematically. One main cause for the formation of such subpopulations is the progress of all cells through the cell cycle. The interaction of potential cell cycle specific variations in the cell behavior with large‐scale process conditions can be optimally determined by means of (partially) synchronized cultivations, with subsequent population resolved model analysis. Therefore, it is desirable to synchronize a culture with minimal perturbation, which is possible with different yield and quality using physical selection methods, but not with frequently used chemical or whole‐culture methods. Conventional nonsynchronizing methods with subsequent cell‐specific, for example, flow cytometric analysis, can only resolve cell‐limited effects of the cell cycle. In this work, we demonstrate countercurrent‐flow centrifugal elutriation as a useful physical method to enrich mammalian cell populations within different phases of a cell cycle, which can be further cultivated for synchronized growth in bioreactors under physiological conditions. The presented combined approach contrasts with other physical selection methods especially with respect to the achievable yield, which makes it suitable for bioreactor scale cultivations. As shown with two industrial cell lines (CHO‐K1 and human AGE1.HN), synchronous inocula can be obtained with overall synchrony degrees of up to 82% in the G1 phase, 53% in the S phase and 60% in the
phase, with enrichment factors (
) of 1.71, 1.79, and 4.24 respectively. Cells are able to grow with synchrony in bioreactors over several cell cycles. This strategy, combined with population‐resolved model analysis and parameter extraction as described in the accompanying paper, offers new possibilities for studies of cell lines and processes at levels of cell cycle and population under physiological conditions. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:165–174, 2015
Methodological strategies for transgene copy number quantification in goats (Capra hircus) using real‐time PCR
Authors: Batista Ribrio I. T. P. , Luciano Maria C. S. , Teixeira Dárcio I. A. , Freitas Vicente J. F. , Melo Luciana M. , Andreeva Lyudmila E. , Serova Irina A. , Serov Oleg L.
Published: July 2014

Taking into account the importance of goats as transgenic models, as well as the rarity of copy number (CN) studies in farm animals, the present work aimed to evaluate methodological strategies for accurate and precise transgene CN quantification in goats using quantitative polymerase chain reaction (qPCR). Mouse and goat lines transgenic for human granulocyte‐colony stimulating factor were used. After selecting the best genomic DNA extraction method to be applied in mouse and goat samples, intra‐assay variations, accuracy and precision of CN quantifications were assessed. The optimized conditions were submitted to mathematical strategies and used to quantify CN in goat lines. The findings were as follows: validation of qPCR conditions is required, and amplification efficiency is the most important. Absolute and relative quantifications are able to produce similar results. For normalized absolute quantification, the same plasmid fragment used to generate goat lines must be mixed with wild‐type goat genomic DNA, allowing the choice of an endogenous reference gene for data normalization. For relative quantifications, a resin‐based genomic DNA extraction method is strongly recommended when using mouse tail tips as calibrators to avoid tissue‐specific inhibitors. Efficient qPCR amplifications (≥95%) allow reliable CN measurements with SYBR technology. TaqMan must be used with caution in goats if the nucleotide sequence of the endogenous reference gene is not yet well understood. Adhering to these general guidelines can result in more exact CN determination in goats. Even when working under nonoptimal circumstances, if assays are performed that respect the minimum qPCR requirements, good estimations of transgene CN can be achieved. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1390–1400, 2014
Moving through three‐dimensional phase diagrams of monoclonal antibodies
Authors: Rakel Natalie , Baum Miriam , Hubbuch Jürgen
Published: July 2014

Protein phase behavior characterization is a multivariate problem due to the high amount of influencing parameters and the diversity of the proteins. Single influences on the protein are not understood and fundamental knowledge remains to be obtained. For this purpose, a systematic screening method was developed to characterize the influence of fluid phase conditions on the phase behavior of proteins in three‐dimensional phase diagrams. This approach was applied to three monoclonal antibodies to investigate influences of pH, protein and salt concentrations, with five different salts being tested. Although differences exist between the antibodies, this extensive study confirmed the general applicability of the Hofmeister series over the broad parameter range analyzed. The influence of the different salts on the aggregation (crystallization and precipitation) probability was described qualitatively using this Hofmeister series, with a differentiation between crystallization and precipitation being impossible, however. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1103–1113, 2014
A novel approach to monitor clearance of host cell proteins associated with monoclonal antibodies
Authors: Aboulaich Nabila , Chung Wai Keen , Thompson Jenny Heidbrink , Larkin Christopher , Robbins David , Zhu Min
Published: July 2014

Co‐purification of a subset of host cell proteins (HCPs) with monoclonal antibodies (mAbs) during the capture of mAbs on Protein A affinity chromatography is primarily caused by interactions of HCPs with the mAbs. To date, there is limited information about the identity of those HCPs due to the difficulty in detecting low abundance HCPs in the presence of a large amount of the mAb. Here, an approach is presented that allows identification of HCPs that specifically associate with the mAb, while avoiding interference from the mAb itself. This approach involves immobilization of purified mAb onto chromatography resin via cross‐linking, followed by incubation with HCPs obtained from supernatant of non‐mAb producer cells that are representative of the expression systems used in mAb manufacturing. The HCPs that bind to the mAb are recovered and identified using mass spectrometry. This approach has not only allowed a comprehensive comparison of HCP subpopulations that associate with different mAbs, but also enabled monitoring of the effects of a variety of wash modifiers on the dissociation of individual HCP–mAb interactions. The dissociation of HCPs that associated with the mAb was monitored by enzyme‐linked immunosorbent assay and mass spectrometry. This approach can be utilized as a screening tool to assist the development of effective and targeted wash steps in Protein A chromatography that ensures not only reduction of HCP levels copurified with the mAb but also removal of specific HCPs that may have a potential impact on mAb structural stability and patient safety. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1114–1124, 2014
New Derivatives of Nonactic and Homononactic Acids from Bacillus pumilus Derived from Breynia fruticosa
Authors: Han Li , Huo Peiyuan , Chen Huahong , Li Songtao , Jiang Yi , Li Liya , Xu Lihua , Jiang Chenglin , Huang Xueshi
Published: July 2014

Six new nonactic and homononactic acid derivatives, ethyl homononactate (1), ethyl nonactate (2), homononactyl homononactate (6), ethyl homononactyl nonactate (7), ethyl homononactyl homononactate (8), and ethyl nonactyl nonactate (9), as well as four known compounds, homononactic acid (3), nonactic acid (4), homononactyl nonactate (5), and bishomononactic acid (10), were isolated from culture broth of Bacillus pumilus derived from Breynia fruticosa. The structures of new compounds were elucidated by spectroscopic analysis and chemical methods. The optical purities of 1–6 were determined by HPLC/MS after treatment with L‐phenylalanine methyl ester. The dimeric compounds 5–9 showed weak cytotoxic activities against five human cancer cell lines (IC50 19–100 μg/ml).
Suppression of Inflammatory Cytokine Production by ar‐Turmerone Isolated from Curcuma phaeocaulis
Authors: Oh Sera , Han A Rheum , Park Hye Ryeon , Jang Eun Jung , Kim Hyo Kyeong , Jeong Mi Gyeong , Song Hyuna , Park Gun Hwa , Seo Eun Kyoung , Hwang Eun Sook
Published: July 2014

Rhizomes of Curcuma phaeocaulis Valeton (Zingiberaceae) have traditionally been used for controlling inflammatory conditions. Numerous studies have aimed to isolate and characterize the bioactive constituents of C. phaeocaulis. It has been reported that its anti‐inflammatory properties are a result of cyclooxygenase‐2 inhibition; however, its effect on the T‐cell function remains to be elucidated. In this study, four known sesquiterpenoids, viz., ar‐turmerone (TM), germacrone (GM), (+)‐(4S,5S)‐germacrone‐4,5‐epoxide (GE), and curzerenone (CZ), were isolated from C. phaeocaulis rhizomes and evaluated for their effects on the CD4+ T‐cell function. While GM, GE, and CZ had no effect on the activation of splenic T cells or CD4+ T cells, TM suppressed the interferon (IFN)‐γ production, without affecting the interleukin (IL)‐4 expression. TM also decreased the expression of IL‐2 in CD4+ T cells, but did not change their cell‐division rates upon stimulation. These results suggest that TM, a major constituent of C. phaeocaulis rhizomes selectively exerts potent anti‐inflammatory effects via suppression of the inflammatory cytokines IFN‐γ and IL‐2.
MKP‐1 is a target of miR‐210 and mediate the negative regulation of miR‐210 inhibitor on hypoxic hPASMC proliferation
Authors: Jin Youpeng , Pang Tingting , Nelin Leif D. , Wang Wei , Wang Yulin , Yan Jinchun , Zhao Chun
Published: July 2014

Chonic hypoxia, smooth muscle cell (SMC) proliferation and vascular remodeling are hallmark features of pathogenic pulmonary artery hypertension. MicroRNAs (miRNAs), endogenously expressed small noncoding RNAs, regulate gene expression at the post‐transcriptional level. MiR‐210 is considered a “master miRNA” in the control of diverse functions in hypoxic cells and tissues and has a cytoprotective function in pulmonary artery SMCs during hypoxic stress. MiR‐210 is also upregulated in lung tissue of chonically hypoxic mice suffering from pulmonary hypertension. Jin et al. () showed that mice deficient in mitogen‐activated protein kinase phosphatase 1 (MKP‐1) had severe hypoxia‐induced pulmonary hypertension, so MKP‐1 may be important in the progression of hypoxic pulmonary artery hypertension. We investigated the possible interactions between miR‐210 and MKP‐1 and the effect on cell proliferation in hypoxic human pulmonary artery SMCs (hPASMCs). miR‐210 was significantly increased in cultured hPASMCs exposed to 1% O2 hypoxia for 48 h, as was MKP‐1 mRNA and protein expression. Furthermore, inhibiting miR‐210 expression increased MKP‐1 mRNA and protein expression in hPASMCs and decreased cell proliferation under hypoxia. Conversely, overexpressing miR‐210 prevented hypoxia‐induced MKP‐1 expression with no effect on cell proliferation. siRNA knockdown of MKP‐1 abolished the miR‐210‐inhibition prevention of cell proliferation under hypoxia. MKP‐1 is a target of miR‐210 and could mediate the negative regulation of miR‐210 inhibition on hypoxic hPASMCs.
Nano‐ and Microscale Engineering of the Molybdenum Disulfide‐Based Catalysts for Syngas to Ethanol Conversion
Authors: Konarova Muxina , Tang Fengqiu , Chen Jiuling , Wang Geoff , Rudolph Victor , Beltramini Jorge
Published: July 2014

Nickel‐promoted MoS2, unsupported catalysts and laponite‐supported alcohol synthesis catalysts were synthesised by using microemulsion (ME) and hydrothermal (HT) methods. Highly ordered sulfide slabs, consisting of up to seven layers, were visible in the TEM images of HT‐based NiMoS2 catalysts. In contrast, disordered sulfide layers were identified in ME‐based NiMoS2 catalysts. High catalytic activity was observed in ME‐based supported (laponite‐supported NiMoS2) and unsupported catalysts. After the CO hydrogenation reaction, the catalysts were characterised by X‐ray photoelectron spectroscopy and inductively coupled plasma–mass spectrometry elemental analyses, which detected a significant sulfur loss in ME‐based NiMoS2 catalysts and minor sulfur loss in HT‐based NiMoS2 catalysts. In addition to the large surface area (120 m2 g−1), disordered sulfide structure, and exposed active sites, ME‐based NiMoS2 catalysts demonstrated higher alcohol selectivity (61 mol %) than HT‐based NiMoS2 catalysts (15 mol %). Correlations between the catalyst morphology, surface active components, and alcohol selectivity are discussed herein.