bluuebunny/crossref_metadata_2025 huggingface dataset:
The Triple‐Bond Metathesis of Aryldiazonium Salts: A Prospect for Dinitrogen Cleavage
Authors: Lackner Aaron D. , Fürstner Alois
Published: September 2015

The {N2} unit of aryldiazonium salts undergoes unusually facile triple‐bond metathesis on treatment with molybdenum or tungsten alkylidyne ate complexes endowed with triphenylsilanolate ligands. The reaction transforms the alkylidyne unit into a nitrile and the aryldiazonium entity into an imido ligand on the metal center, as unambiguously confirmed by X‐ray structure analysis of two representative examples. A tungsten nitride ate complex is shown to react analogously. Since the bonding situation of an aryldiazonium salt is similar to that of metal complexes with end‐on‐bound dinitrogen, in which {N2}→M σ donation is dominant and electron back donation minimal, the metathesis described herein is thought to be a conceptually novel strategy toward dinitrogen cleavage devoid of any redox steps and, therefore, orthogonal to the established methods.
Excited‐State Dynamic Planarization of Cyclic Oligothiophenes in the Vicinity of a Ring‐to‐Linear Excitonic Behavioral Turning Point
Authors: Park Kyu Hyung , Kim Pyosang , Kim Woojae , Shimizu Hideyuki , Han Minwoo , Sim Eunji , Iyoda Masahiko , Kim Dongho
Published: September 2015

Excited‐state dynamic planarization processes play a crucial role in determining exciton size in cyclic systems, as reported for π‐conjugated linear oligomers. Herein, we report time‐resolved fluorescence spectra and molecular dynamics simulations of π‐conjugated cyclic oligothiophenes in which the number of subunits was chosen to show the size‐dependent dynamic planarization in the vicinity of a ring‐to‐linear behavioral turning point. Analyses on the evolution of the total fluorescence intensity and the ratio between 0–1 to 0–0 vibronic bands suggest that excitons formed in a cyclic oligothiophene composed of six subunits fully delocalize over the cyclic carbon backbone, whereas those formed in larger systems fail to achieve complete delocalization. With the aid of molecular dynamics simulations, it is shown that distorted structures unfavorable for efficient exciton delocalization are more easily populated as the size of the cyclic system increases.
Intramolecular Aminoboration of Unfunctionalized Olefins
Authors: Yang Chun‐Hua , Zhang Yu‐Shi , Fan Wen‐Wen , Liu Gong‐Qing , Li Yue‐Ming
Published: September 2015

A direct and catalyst‐free method for the intramolecular aminoboration of unfunctionalized olefins is reported. In the presence of BCl3 (1 equiv) as the sole boron source, intramolecular aminoboration of sulfonamide derivatives of 4‐penten‐1‐amines, 5‐hexen‐1‐amines, and 2‐allylanilines proceeded readily without the use of any catalyst. The boronic acids obtained after hydrolysis could be converted into the corresponding pinacol borates in a straightforward manner by treatment with pinacol under anhydrous conditions.
Thermoelectricity Generation and Electron–Magnon Scattering in a Natural Chalcopyrite Mineral from a Deep‐Sea Hydrothermal Vent
Authors: Ang Ran , Khan Atta Ullah , Tsujii Naohito , Takai Ken , Nakamura Ryuhei , Mori Takao
Published: September 2015

Current high‐performance thermoelectric materials require elaborate doping and synthesis procedures, particularly in regard to the artificial structure, and the underlying thermoelectric mechanisms are still poorly understood. Here, we report that a natural chalcopyrite mineral, Cu1+xFe1−xS2, obtained from a deep‐sea hydrothermal vent can directly generate thermoelectricity. The resistivity displayed an excellent semiconducting character, and a large thermoelectric power and high power factor were found in the low x region. Notably, electron–magnon scattering and a large effective mass was detected in this region, thus suggesting that the strong coupling of doped carriers and antiferromagnetic spins resulted in the natural enhancement of thermoelectric properties during mineralization reactions. The present findings demonstrate the feasibility of thermoelectric energy generation and electron/hole carrier modulation with natural materials that are abundant in the Earth’s crust.
The Instability of Ni{N(SiMe3)2}2: A Fifty Year Old Transition Metal Silylamide Mystery
Authors: Faust Michelle , Bryan Aimee M. , Mansikkamäki Akseli , Vasko Petra , Olmstead Marilyn M. , Tuononen Heikki M. , Grandjean Fernande , Long Gary J. , Power Philip P.
Published: September 2015

The characterization of the unstable NiIIbis(silylamide) Ni{N(SiMe3)2}2(1), its THF complex Ni{N(SiMe3)2}2(THF) (2), and the stable bis(pyridine) derivative trans‐Ni{N(SiMe3)2}2(py)2(3), is described. Both1and2decompose at ca. 25 °C to a tetrameric NiIspecies, [Ni{N(SiMe3)2}]4(4), also obtainable from LiN(SiMe3)2and NiCl2(DME). Experimental and computational data indicate that the instability of1is likely due to ease of reduction of NiIIto NiIand the stabilization of4through dispersion forces.
Shaped Ceria Nanocrystals Catalyze Efficient and Selective Para‐Hydrogen‐Enhanced Polarization
Authors: Zhao Evan W. , Zheng Haibin , Zhou Ronghui , Hagelin‐Weaver Helena E. , Bowers Clifford R.
Published: September 2015

Intense para‐hydrogen‐enhanced NMR signals are observed in the hydrogenation of propene and propyne over ceria nanocubes, nano‐octahedra, and nanorods. The well‐defined ceria shapes, synthesized by a hydrothermal method, expose different crystalline facets with various oxygen vacancy densities, which are known to play a role in hydrogenation and oxidation catalysis. While the catalytic activity of the hydrogenation of propene over ceria is strongly facet‐dependent, the pairwise selectivity is low (2.4 % at 375 °C), which is consistent with stepwise H atom transfer, and it is the same for all three nanocrystal shapes. Selective semi‐hydrogenation of propyne over ceria nanocubes yields hyperpolarized propene with a similar pairwise selectivity of (2.7 % at 300 °C), indicating product formation predominantly by a non‐pairwise addition. Ceria is also shown to be an efficient pairwise replacement catalyst for propene.
Formation of Ruthenium Carbenes by gem‐Hydrogen Transfer to Internal Alkynes: Implications for Alkyne trans‐Hydrogenation
Authors: Leutzsch Markus , Wolf Larry M. , Gupta Puneet , Fuchs Michael , Thiel Walter , Farès Christophe , Fürstner Alois
Published: September 2015

Insights into the mechanism of the unusual trans‐hydrogenation of internal alkynes catalyzed by {Cp*Ru} complexes were gained by para‐hydrogen (p‐H2) induced polarization (PHIP) transfer NMR spectroscopy. It was found that the productive trans‐reduction competes with a pathway in which both H atoms of H2 are delivered to a single alkyne C atom of the substrate while the second alkyne C atom is converted into a metal carbene. This “geminal hydrogenation” mode seems unprecedented; it was independently confirmed by the isolation and structural characterization of a ruthenium carbene complex stabilized by secondary inter‐ligand interactions. A detailed DFT study shows that the trans alkene and the carbene complex originate from a common metallacyclopropene intermediate. Furthermore, the computational analysis and the PHIP NMR data concur in that the metal carbene is the major gateway to olefin isomerization and over‐reduction, which frequently interfere with regular alkyne trans‐hydrogenation.
Manganese‐Catalyzed Oxidative Azidation of Cyclobutanols: Regiospecific Synthesis of Alkyl Azides by CC Bond Cleavage
Authors: Ren Rongguo , Zhao Huijun , Huan Leitao , Zhu Chen
Published: September 2015

A novel, manganese‐catalyzed oxidative azidation of cyclobutanols is described. A wide range of primary, secondary, and tertiary alkyl azides were generated in synthetically useful yields and exclusive regioselectivity. Aside from linear alkyl azides, otherwise elusive medium‐sized cyclic azides were also readily prepared. Preliminary mechanistic studies reveal that the reaction likely proceeds by a radical‐mediated CC bond cleavage/CN3 bond formation pathway.
A Photoactive Carbon‐Monoxide‐Releasing Protein Cage for Dose‐Regulated Delivery in Living Cells
Authors: Fujita Kenta , Tanaka Yuya , Abe Satoshi , Ueno Takafumi
Published: September 2015

Protein cages can serve as bioinorganic molecular templates for functionalizing metal compounds to regulate cellular signaling. We succeeded in developing a photoactive CO‐releasing system by constructing a composite of ferritin (Fr) containing manganese–carbonyl complexes. When Arg52 adjacent to Cys48 of Fr is replaced with Cys, the Fr mutant stabilizes the retention of 48 Mn–carbonyl moieties, which can release the CO ligands under light irradiation, although wild‐type Fr retains very few Mn moieties. The amount of released CO is regulated by the extent of irradiation. This could reveal an optimized dose for cooperatively activating the nuclear factor κB (NF‐κB) in mammalian cells and the tumor necrosis factor α (TNF‐α). These results suggest that construction of a CO‐releasing protein cage will advance of research in CO biology.
Al2O3 Nanosheets Rich in Pentacoordinate Al3+ Ions Stabilize Pt‐Sn Clusters for Propane Dehydrogenation
Authors: Shi Lei , Deng Gao‐Ming , Li Wen‐Cui , Miao Shu , Wang Qing‐Nan , Zhang Wei‐Ping , Lu An‐Hui
Published: September 2015

In heterogeneous catalysis, supports play a crucial role in modulating the geometric and electronic structure of the active metal phase for optimizing the catalytic performance. A γ‐Al2O3 nanosheet that contains 27 % pentacoordinate Al3+ sites can nicely disperse and stabilize raft‐like Pt‐Sn clusters as a result of strong interactions between metal and support. Consequently, there are strong electronic interactions between the Pt and Sn atoms, resulting in an increase in the electron density of the Pt sites. When used in the propane dehydrogenation reaction, this catalyst displayed an excellent specific activity for propylene formation with >99 % selectivity, and superior anti‐coking and anti‐sintering properties. Its exceptional ability to maintain the high activity and stability at ultrahigh space velocities further showed that the sheet construction of the catalyst facilitated the kinetic transfer process.
Effect of secondary air mass flow rate on the airflow and combustion characteristics and NOx formation of the low‐volatile coal‐fired swirl burner
Authors: Li Song , Li Zhengqi , Jiang Bingkun , Chen Zhichao , Zhang Xiqian
Published: September 2015

Laboratory experiments and industrial‐scale experiments on 300‐MW low‐volatile coal‐fired boiler were performed under deep air staging. Aerodynamic characteristics, gas temperature and concentrations, furnace temperature, and boiler efficiency were measured for various secondary air mass flow rates. Under deep air staging, a steady central recirculation zone forms near the burner nozzle. With a decreasing flow rate, the swirl intensity and maximum axial, radial, and tangential velocities decrease; between X/D = 0–0.8, the velocity decay rate decreases, and the relative reverse flow rate decreases. In the early stage, the maximum axial mixing rate decreases; the primary air concentration increases slightly. A decrease in secondary air‐box damper opening decreases the gas temperature and its increasing rate, generating a farther ignition position. In the initial stage, the O2 consumption rate and CO concentration increase, while the NOx concentration decreases. In the later stage, O2 concentration remains almost constant below 2%, and the CO concentrations exceed 15 000 ppm, which restrain NOx formation notably. Near the water‐cooled wall, flue gas temperature varies slightly, and O2 concentration exceeds 3%. Along radial direction 1.5364 ≤ R0/D0 ≤ 1.8708, the O2 concentrations are below 2%, and CO concentrations exceed 6000 ppm. A decreasing damper opening decreases furnace temperature in the primary combustion zone slightly. NOx emission decreases from 833.4 to 769.9 mg/m3 (6% O2), unburnt carbon increases from 5.18% to 6.84%, and boiler efficiency decreases from 91.53% to 90.99%. Copyright © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Development of a cashew nut shell liquid (CNSL)‐based polymer for antibacterial activity
Authors: Kanehashi Shinji , Masuda Risa , Yokoyama Kota , Kanamoto Taisei , Nakashima Hideki , Miyakoshi Tetsuo
Published: September 2015

A biobased polymer derived from cashew nut shell liquid (CNSL) as a renewable resource was investigated for use as an antibacterial material. CNSL is a mixture of aromatics containing cardanol as the main component and cardol and 2‐methylcardol as minor components. CNSL composition analyses showed that the minor components (i.e., cardol and 2‐methylcardol) in CNSL had higher contents of unsaturated structures than cardanol. These higher unsaturated contents promoted the thermal polymerization in the preparation of an epoxy CNSL prepolymer (ECNP). The biobased polymer film was fabricated by the reaction of amine compounds and ECNP without any organic solvent. The ECNP film took less than 2.0 h to reach a hardened dry condition at room temperature because of the crosslinking reaction between epoxy and amine groups. The antibacterial activities of the biobased polymer against Escherichia coli and Staphylococcus aureus were evaluated. CNSL showed antibacterial activity against S. aureus, whereas epoxy CNSL and ECNP alone showed no significant antibacterial activity against E. coli or S. aureus. This indicated that the antibacterial activity was based on the phenolic and catechol hydroxyl groups of CNSL. In addition, a biobased polymer film derived from CNSL and diamine showed antibacterial activity against both E. coli and S. aureus, even with alcohol conditioning. This suggested that the antibacterial activity was certainly fixed in the structure of the ECNP‐based polymers after the standard antisepsis treatment in medical facilities. Therefore, this biobased polymer could be useful in antibacterial materials as a coating and resin for health care applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42725.
A carbazole–triphenylamine copolymer‐bearing pendant europium complexes: Synthesis and luminescence properties
Authors: Jin Yuxia , Zuo Weiwei , Gao Hongyan , Fu Linfeng , Liu Yingliang , Wu Wenbo , Xu Shengang , Cao Shaokui
Published: September 2015

A novel carbazole–triphenylamine copolymer‐bearing pendant bipyridine PM1TPA and corresponding europium (III) complexed polymer PM1TPA–Eu–x, in which the values of x are 0.1, 0.5, and 1.0 representing the molar ratio of bipyridine ligands complexed with Eu(III), were designed and synthesized. Their chemical structures were confirmed by 1H NMR, FT‐IR, and elemental analysis. Both PM1TPA and PM1TPA–Eu shows good solubility in common organic solvents such as tetrahydrofuran (THF) and CHCl3. The 5% weight loss temperature (Td5%) of PM1TPA and PM1TPA–Eu–1.0 are 363oC and 306oC, respectively. The photoluminescence (PL) spectra of PM1TPA–Eu in solution consists of two emission bands, one in the 400–570 nm region and another at 612 nm, corresponding to the emission of polymer main chain and europium complexes, respectively. When the concentration of PM1TPA–Eu–1.0 in THF solution increases, the PL intensity in the 400–570 nm regions became more and more weaker. And only the characteristic emission of europium complex was observed in the solid film, which indicates that the excited energy absorbed by the polymer backbone was efficiently transferred to the europium complexes. Furthermore, nearly monochromatic red electroluminescence from europium complex was observed from the polymeric light‐emitting diode using PM1TPA–Eu–1.0 as the emissive layer under 25 V forward bias. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42746.
Mechanical and thermal properties of poly(butylene succinate)/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) biodegradable blends
Authors: Phua Y. J. , Pegoretti A. , Araujo T. Medeiros , Ishak Z. A. Mohd
Published: September 2015

Biodegradable polymer blends of poly(butylene succinate) (PBS) and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) were prepared with different compositions. The mechanical properties of the blends were studied through tensile testing and dynamic mechanical thermal analysis. The dependence of the elastic modulus and strength data on the blend composition was modeled on the basis of the equivalent box model. The fitting parameters indicated complete immiscibility between PBS and PHBV and a moderate adhesion level between them. The immiscibility of the parent phases was also evidenced by scanning electron observation of the prepared blends. The thermal properties of the blends were studied through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results showed an enhancement of the crystallization behavior of PBS after it was blended with PHBV, whereas the thermal stability of PBS was reduced in the blends, as shown by the TGA thermograms. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42815.
Urea‐activated 4,4'‐oxibis‐(benzenesulfonyl hydrazide) as foaming agent for low‐density unsaturated polyester resin manufacturing
Authors: Zhang Yi‐Fan , Wang Xiao‐Jun , Pan Zhi‐Gang , Hong Cheng‐Ming , Ji Gao‐Feng
Published: September 2015

The activation of foaming agent is critical to its application. In this study, 4,4′‐oxibis‐(benzenesulfonyl hydrazide) (OBSH) activated by urea was used in the manufacture of low‐density unsaturated polyester resin (LDUPR), and the results were compared with that of OBSH activated by zinc oxide and zinc stearate. The experiment results showed that the activation of OBSH by urea was better than by zinc oxide or by zinc stearate. A novel hydrogen bond activation mechanism of urea is presented in this research. Two stages, including the induction stage and the foaming stage, were proposed in the LDUPR manufacture according to the gas evolution curves of activated OBSH. The decomposition temperature and the decomposition time of OBSH activated by urea were determined to match the gelation time of UPR for the manufacture of LDUPR. The disadvantageous chemical behaviors of activated OBSH were eliminated in the induction treatment. The activated OBSH via induction treatment released gas maximally and distributed gas homogeneously in the resin glue, resulting in a better foaming effect than that of the previous foaming agents. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42824.
Defining a strain‐induced time constant for oriented low shear‐induced structuring in high consistency MFC/NFC‐filler composite suspensions
Authors: Dimic‐Misic Katarina , Maloney Thaddeus C. , Gane Patrick A. C.
Published: September 2015

Micro and nanofibrillated cellulose is an essentially one‐dimensional high aspect‐ratio particle material, which can undergo two‐dimensional layer (band) structuring under shear. Controlling the evolving rheological properties in aqueous suspension is essential for industrial applications in composite materials. This study focuses on an as yet considered to be unreported phenomenon of structure hardening under low shear. The timescale of the quasi gelation‐controlled structure formation under low shear is studied using the large gap vane‐in‐cup geometry of the Brookfield viscometer. It is proposed that localized structure forms within continuous shear bands, similar to quasi liquid‐crystal formation. By extrapolating a characteristic structure growth parameter to the rotation speed at which it becomes zero, the strain‐induced structure time constant, tgel, can be obtained as
(= f (Ω)) = 1/tgel for the range Ω = 10–100/min. The time constant of low shear structure formation is shown to be separable from the static viscoelastic structure build under oscillation in concentrated composite suspension using plate‐plate geometry, which is manifest by a Weissenberg normal force response on switching to applied shear, when the time constant of structuration tgel is long. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42827.
Polystyrene with trifluoromethyl units: Monomer reactivity ratios, thermal behavior, flammability, and thermal degradation kinetics
Authors: Wiacek Malgorzata , Wesolek Dorota , Rojewski Szymon , Bujnowicz Krzysztof , Jurczyk Sebastain , Kurcok Malgorzata , Schab‐Balcerzak Ewa
Published: September 2015

Chemical modification based on incorporation of flame retardants (FR) into the polymer backbone was used in order to reduce polystyrene flammability. 3‐(trifluoromethyl)styrene (StCF3) and 3,5‐bis(trifluoromethyl)styrene (St(CF3)2) were applied as reactive FR. Copolymers were synthesized with different feed ratios and it gave series of copolymers with various amounts of StCF3 and St(CF3)2 (5–50% mol/mol of St). Glass transition temperature (Tg) and thermal stability of obtained (co)polymers were determined from differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. Kinetic parameters such as the thermal decomposition activation energy (E) and frequency factor (A) were estimated by Ozawa and Kissinger models. Pyrolysis combustion flow calorimeter (PCFC) was applied as a tool for assessing the flammability of the synthesized (co)polymers. Relative reactivity ratios were determined by applying the conventional linearization Jaacks method (rSt = 1.34, rStCF3 = 0.54), (rSt = 0.47, rSt(CF3)2 = 0.13). The results suggest that incorporation of fluorinated styrenes into PSt enchance flame retardance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42839.
Solution‐blown SPEEK/POSS nanofiber–nafion hybrid composite membranes for direct methanol fuel cells
Authors: Wang Hang , Zhuang Xupin , Tong Junying , Li Xiaojie , Wang Wei , Cheng Bowen , Cai Zhanjun
Published: September 2015

This study aims to develop novel hybrid composite membranes (NHMs) by impregnating Nafion solution into the porous sulfonated poly(ether ether ketone)/polyhedral oligomeric silsesquioxanes (SPEEK/POSS) nanofibers (NFs). The composite membrane was prepared by solution blowing of a mixture of SPEEK/POSS solution. The characteristics of the SPEEK/POSS NFs and the NHMs, including morphology, thermal stability, and performance of membrane as PEMs, were investigated. The performance of NHMs was compared with that of Nafion117 and SPEEK/Nafion composite membranes. Results showed that the introduction of POSS improved the proton conductivity, water swelling, and methanol permeability of membranes. A maximum proton conductivity of 0.163 S cm−1was obtained when the POSS content was 6 wt % at 80°C, which was higher than that of Nafion117 and SPEEK/Nafion. NHMs could be used as proton exchange membranes (PEMs) for fuel cell applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42843.
Nano‐crystalline cellulose, chemical blowing agent, and mold temperature effect on morphological, physical/mechanical properties of polypropylene
Authors: Yousefian Hajar , Rodrigue Denis
Published: September 2015

Polypropylene (PP)/nano‐crystalline cellulose (NCC) composites and foams were produced through extrusion compounding combined with injection molding. From the samples produced, a complete morphological, physical, and mechanical analysis was performed to study the effect of NCC concentration (0–5wt %), foaming agent content (0 to 2wt %) and mold temperature (30°C and 80°C). NCC was very effective to reduce cell size (42–71%) and increase cell density (5–37 times) of the foams, while slightly increasing the overall density (2–7%). The results showed that NCC addition increased the specific tensile modulus (15–22%), specific tensile strength (1–14%) and specific flexural modulus (13–26%) of PP, but decreased specific impact strength (10–20%) and specific elongation at break (50–96%). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42845.
“The Sinusoid” in the Liver: Lessons Learned from the Original Definition by Charles Sedgwick Minot (1900)
Authors: Wake Kenjiro , Sato Tetsuji
Published: September 2015

The hepatic sinusoid with its associated sinusoidal cells is a multifunctional cell‐complex in the liver. Despite recent advances in research on the hepatic sinusoid, no investigator has played a more basic role in its characterization than Charles Sedgwick Minot (1852–1914), a pioneer who distinguished the sinusoid from the blood‐capillary as early as 1900. According to Minot, sinusoids are typically larger in diameter than capillaries, particularly at the early embryonic stage. They closely approach the parenchymal tissue, are formed passively by the adjacent parenchymal tissue, and are on rare occasion surrounded with connective tissue. Sinusoids (sinus‐like) are small blood‐channels formed by subdivision of the lumen of large blood vessels (sinuses) by the invasion of developing parenchymal cell‐cords. Although some of Minot's definitions may no longer be accepted, he described some fundamental and interesting characteristics of sinusoids, to which we have not paid much attention. Here, we have attempted to illustrate lessons we have learned from Minot's view point of sinusoids at this occasion of centenary of his death. Anat Rec, 298:2071–2080, 2015. © 2015 Wiley Periodicals, Inc.
The Atiahara site revisited: An early coastal settlement in Tubuai (Austral Islands, French Polynesia)
Authors: HERMANN AYMERIC , BOLLT ROBERT , CONTE ERIC
Published: September 2015

The Atiahara site is the first and only excavated site on Tubuai Island (Austral archipelago, French Polynesia). It was accidently discovered in 1994 and has been excavated on several occasions since then, over a surface of 197 m2. This paper aims to present a compilation of the data available from the excavations, with a specific focus on stratigraphy, a spatial analysis of preserved occupations and new radiocarbon dates. We report a short dating sequence running from 1215 to 1390 CE, which makes the Atiahara site one of the earliest settlements in the Austral Islands. Finally, we mention the potential for tackling important topics in Polynesian archaeology through this key site, including the evolution of material culture and fishing strategies, socio‐economic dynamics within a central Polynesian domestic context and possible climate variability in the region.
Design, Synthesis, and Evaluation of Novel 1,2,3‐Triazole‐Tethered Glycolipids as Vaccine Adjuvants
Authors: Bhunia Debabrata , Pallavi Preethi M. C. , Bonam Srinivasa Reddy , Reddy Sandeep A. , Verma Yogesh , Halmuthur M. Sampath Kumar
Published: September 2015

A Cu‐mediated azide–alkyne click chemistry protocol was employed for the synthesis of a focused library of novel 1,2,3‐triazolyl conjugates bearing various carbohydrate‐steroid/triterpenoid entities. The immunogenicity of these compounds was examined initially by ex vivo assays. The lead compound 15g was further subjected to in vivo evaluation in BALB/c mice immunized with ovalbumin. These in vivo biological studies revealed an increase in B cell‐mediated proliferation, higher expression levels of IL‐2, TNF‐α, IL‐12, and IFN‐γ indicating Th1 activation, together with an enhanced OVA‐specific antibody (IgG) response compared to alum, affirming adjuvanticity of these glycolipids. The primary indications of response skewed toward Th1 immunity induced by the new triazoyl analogs indicate the potential of these molecules for possible application as adjuvants.
Abstraction‐Based Verification and Synthesis for Prognosis of Discrete Event Systems
Authors: Yokotani Misato , Kondo Tetsuya , Takai Shigemasa
Published: September 2015

In this paper, we develop a theoretical framework for abstraction‐based failure prognosis of partially observed discrete event systems. The purpose of using abstraction is to verify prognosability and synthesize a prognoser based on the abstracted models with fewer states and transitions. We present conditions under which prognosability can be verified and a prognoser can be synthesized based on the abstracted models of the system and the specification.
Überprüfung der zusätzlichen Regeln für ∅︁40 mm nach EC2
Authors: Schoening Janna , Hegger Josef
Published: September 2015

Die Ausführung von hochbewehrten Stahlbetonbauteilen wird durch die Verwendung von großen Stabdurchmessern erheblich vereinfacht. In der aktuellen europäischen Normung [1, 2] beträgt der maximal zulässige Bewehrungsstabdurchmesser 40 mm. Stabdurchmesser > ∅︁40 mm erfordern eine bauaufsichtliche Zulassung. Allerdings enthält aktuell die Stahlbetonnormung [1, 2] eine Reihe von Zusatzregeln für die Konstruktion mit großen Stabdurchmessern (> ∅︁32 mm). Da nur wenige Untersuchungen zum Tragverhalten von Stahlbetonbauteilen mit großen Stabdurchmessern > ∅︁32 mm vorliegen, wurden das Verbundverhalten und das Tragverhalten von Übergreifungsstößen mit großen Stabdurchmessern in einem Forschungsvorhaben der Arbeitsgemeinschaft industrieller Forschungsvereinigungen (AiF) an der RWTH Aachen untersucht. Die Übertragbarkeit der Bemessungsregeln für Übergreifungen von herkömmlichen Stabdurchmessern auf große Stabdurchmesser und die Erfordernis der Zusatzregeln für große Stabdurchmesser in EC2 [1] und EC2/NA [2] wurden überprüft. Dazu wurden 28 Beam‐End‐Versuche und acht Vierpunkt‐Biegeversuche durchgeführt, um den Einfluss von Stabdurchmesser, Verbundlänge, Betondruckfestigkeit, Querdruck, Querbewehrung und Betondeckung zu bestimmen [3].

In diesem Artikel werden die Versuchsergebnisse von Verbundversuchen und Versuchen an Übergreifungsstößen mit Bewehrungsstäben > ∅︁32 mm zur Beurteilung der Zusatzregeln in EC2 [1] und EC2/NA [2] beschrieben.

Checking of additional rules for ∅︁40 mm according to EC2 – Part 1: Bond and lapped joints

The detailing of reinforcement of high impact structures can be simplified significantly by reinforcing bars with large diameters. According to the current European design and construction standard [1, 2] the valid maximum reinforcing‐bar diameter is 40 mm. Bar diameters ∅︁40 mm are subject to technical approvals. In addition to the detailing rules for conventional bar diameters, tight restrictions regarding construction with large diameter bars (> ∅︁32 mm) exist [1, 2]. Since little investigation for the design and construction of structures with large diameter bars > ∅︁32 mm has been done, the bond behavior and the performance of lapped joints of reinforcing bars with large diameters were investigated at RWTH Aachen University within a research project funded by the German Federation of Industrial Research Associations (AiF). In this study, the transfer of design rules for laps for conventional bar diameters according to EC2 [1] and EC2/NA [2] to large diameter bars and the requirement of tight regulations for large diameter bars were analysed. Therefore, 28 beam‐end tests and eight four‐point bending tests were conducted to determine the effects of bar diameter, bond length, concrete strength, pressure transverse to the potential plane of splitting and confinement by stirrups as well as concrete cover.

This paper presents the test results of bond tests and tests on lapped joints with large diameters > ∅︁32 mm and a comparison with EC2 [1] and EC2/NA [2].
Geognosie versus Geologie: Nationale Denkstile und kulturelle Praktiken bezüglich Raum und Zeit im Widerstreit
Authors: Klemun Marianne
Published: September 2015

Geognosy versus Geology: National Modes of Thought and Cultural Practices Concerning Space and Time in Competition. Natural science investigators at the end of the eighteenth century made use of conflicting labels to position their respective preferred fields of activity in the Earth sciences. This mania for labelling marked their break with natural science and the umbrella term ‘mineralogy’. In this conflict situation of specialist classifications and explanations, two terms in particular were established: geognosy and geology, which covered the very promising project of research in the areas of the ‘origin of the Earth’ and the ‘formation of the Earth’. These and the associated research goals were subsequently accorded a dazzling career. Proceeding from the conceptual core‐meaning in the formation of terms und its semantic spectrum and conceptual shifts in a time of change, my study will look at the identity and heterogeneity functions of geology and geognosy. For whereas in French and English speaking countries the term geology came to be used exclusively (geology, géologie), this was avoided in German, particularly because the term geognosy was preferred. These national differences may be explained with reference to the different cultural and national styles of science: for example the social embedding of geology in the culture of the English gentleman or the French museum culture, and the close connection of ‘German’ geognosy to mining. A further starting point in the analysis of the double use of both geology and geognosy in German speaking countries until 1840 is provided by the different references to temporalization and spatialization of the two terms. And we should also include the practical implications and the epistemic requirements that were bound up with the defence of geognosy in the German speaking world.
Implementation of AMNOG: An industry perspective
Authors: Leverkus Friedhelm , Chuang‐Stein Christy
Published: September 2015

In 2010, the Federal Parliament (Bundestag) of Germany passed a new law (Arzneimittelmarktneuordnungsgesetz, AMNOG) on the regulation of medicinal products that applies to all pharmaceutical products with active ingredients that are launched beginning January 1, 2011. The law describes the process to determine the price at which an approved new product will be reimbursed by the statutory health insurance system. The process consists of two phases. The first phase assesses the additional benefit of the new product versus an appropriate comparator (zweckmäßige Vergleichstherapie, zVT). The second phase involves price negotiation. Focusing on the first phase, this paper investigates requirements of benefit assessment of a new product under this law with special attention on the methods applied by the German authorities on issues such as the choice of the comparator, patient relevant endpoints, subgroup analyses, extent of benefit, determination of net benefit, primary and secondary endpoints, and uncertainty of the additional benefit. We propose alternative approaches to address the requirements in some cases and invite other researchers to help develop solutions in other cases.
Effect of particle size on activation energy and peak temperature of the thermoluminescence glow curve of undoped ZnS nanoparticles
Authors: Chandra B. P. , Chandrakar Raju Kumar , Chandra V. K. , Baghel R. N.
Published: September 2015

This paper reports the effect of particle size on the thermoluminescence (TL) of undoped ZnS nanoparticles. ZnS nanoparticles were prepared using a chemical precipitation method in which mercaptoethanol was used as the capping agent. The nanoparticles were characterized by X‐ray diffraction, field emission gun‐scanning electron microscopy and high‐resolution transmission electron microscopy. When the concentrations of mercaptoethanol used are 0, 0.005, 0.01, 0.015, 0.025, 0.040 and 0.060 M, the sizes of the nanoparticles are 2.86, 2.81, 2.69, 2.40, 2.10, 1.90 and 1.80 nm, respectively. Initially, the TL intensity of UV‐irradiated ZnS nanoparticles increases with temperature, attains a peak value Im for a particular temperature Tm, and then decreases with further increases in temperature. The values of both Im and Tm increase with decreasing nanoparticle size. Whereas the activation energy decreases slightly with decreasing nanoparticle size, the frequency factor decreases significantly as the nanoparticle size is reduced. The order of kinetics for the TL glow curve of ZnS nanoparticles is 2. Expressions are derived for the dependence of activation energy (Ea) and Tm on nanoparticle size, and good agreement is found between the experimental and theoretical results. Copyright © 2015 John Wiley & Sons, Ltd.
Constructing kinetic models of metabolism at genome‐scales: A review
Authors: Srinivasan Shyam , Cluett William R. , Mahadevan Radhakrishnan
Published: September 2015

Constraint‐based modeling of biological networks (metabolism, transcription and signal transduction), although used successfully in many applications, suffer from specific limitations such as the lack of representation of metabolite concentrations and enzymatic regulation, which are necessary for a complete physiologically relevant model. Kinetic models conversely overcome these shortcomings and enable dynamic analysis of biological systems for enhanced in silico hypothesis generation. Nonetheless, kinetic models also have limitations for modeling at genome‐scales chiefly due to: (i) model non‐linearity; (ii) computational tractability; (iii) parameter identifiability; (iv) estimability; and (v) uncertainty. In order to support further development of kinetic models as viable alternatives to constraint‐based models, this review presents a brief description of the existing obstacles towards building genome‐scale kinetic models. Specific kinetic modeling frameworks capable of overcoming these obstacles are covered in this review. The tractability and physiological feasibility of these models are discussed with the objective of using available in vivo experimental observations to define the model parameter space. Among the different methods discussed, Monte Carlo kinetic models of metabolism stand out as potentially tractable methods to model genome scale networks while also addressing in vivo parameter uncertainty.
Engineering of core promoter regions enables the construction of constitutive and inducible promoters in Halomonas sp.
Authors: Li Tingting , Li Teng , Ji Weiyue , Wang Qiuyue , Zhang Haoqian , Chen Guo‐Qiang , Lou Chunbo , Ouyang Qi
Published: September 2015

Halomonas strain TD01, a newly identified halophilic bacterium, has proven to be a promising low‐cost host for the production of chemicals. However, genetic manipulation in Halomonas sp. is still difficult due to the lack of well‐characterized and tunable expression systems. In this study, a systematic, efficient method was exploited to construct both a constitutive promoter library and inducible promoters. Porin, a highly expressed protein in Halomonas TD01, was first identified from the Halomonas TD01 proteome. Subsequent study of the intergenic region upstream of porin led to the identification of a core promoter region, including ‐10 and ‐35 elements. By randomizing the sequence between the ‐35 and ‐10 elements, a constitutive promoter library was obtained with 310‐fold variation in transcriptional activity; an inducible promoter with a >200‐fold induction was built by integrating a lac operator into the core promoter region. As two complementary expression systems, the constitutive and inducible promoters were then employed to regulate the biosynthetic pathway of poly‐3‐hydroxybutyrate (PHB) in Halomonas TD01, demonstrating the usefulness of the expression systems, furthermore, they could be applied in future metabolic engineering of Halomonas TD strains, and the systematic method used in this study can be generalized to other less‐characterized bacterial strains.
Eradication of multidrug‐resistant pseudomonas biofilm with pulsed electric fields
Authors: Khan Saiqa I. , Blumrosen Gaddi , Vecchio Daniela , Golberg Alexander , McCormack Michael C. , Yarmush Martin L. , Hamblin Michael R. , Austen William G.
Published: September 2015

Biofilm formation is a significant problem, accounting for over eighty percent of microbial infections in the body. Biofilm eradication is problematic due to increased resistance to antibiotics and antimicrobials as compared to planktonic cells. The purpose of this study was to investigate the effect of Pulsed Electric Fields (PEF) on biofilm‐infected mesh. Prolene mesh was infected with bioluminescent Pseudomonas aeruginosa and treated with PEF using a concentric electrode system to derive, in a single experiment, the critical electric field strength needed to kill bacteria. The effect of the electric field strength and the number of pulses (with a fixed pulse length duration and frequency) on bacterial eradication was investigated. For all experiments, biofilm formation and disruption were confirmed with bioluminescent imaging and Scanning Electron Microscopy (SEM). Computation and statistical methods were used to analyze treatment efficiency and to compare it to existing theoretical models. In all experiments 1500 V are applied through a central electrode, with pulse duration of 50 μs, and pulse delivery frequency of 2 Hz. We found that the critical electric field strength (Ecr) needed to eradicate 100–80% of bacteria in the treated area was 121 ± 14 V/mm when 300 pulses were applied, and 235 ± 6.1 V/mm when 150 pulses were applied. The area at which 100–80% of bacteria were eradicated was 50.5 ± 9.9 mm2 for 300 pulses, and 13.4 ± 0.65 mm2 for 150 pulses. 80% threshold eradication was not achieved with 100 pulses. The results indicate that increased efficacy of treatment is due to increased number of pulses delivered. In addition, we that showed the bacterial death rate as a function of the electrical field follows the statistical Weibull model for 150 and 300 pulses. We hypothesize that in the clinical setting, combining systemic antibacterial therapy with PEF will yield a synergistic effect leading to improved eradication of mesh infections. Biotechnol. Bioeng. 2016;113: 643–650. © 2015 Wiley Periodicals, Inc.
Engineering of a silica encapsulation platform for hydrocarbon degradation using Pseudomonas sp. NCIB 9816‐4
Authors: Sakkos Jonathan K. , Kieffer Daniel P. , Mutlu Baris R. , Wackett Lawrence P. , Aksan Alptekin
Published: September 2015

Industrial application of encapsulated bacteria for biodegradation of hydrocarbons in water requires mechanically stable materials. A silica gel encapsulation method was optimized for Pseudomonas sp. NCIB 9816‐4, a bacterium that degrades more than 100 aromatic hydrocarbons. The design process focused on three aspects: (i) mechanical property enhancement; (ii) gel cytocompatibility; and (iii) reduction of the diffusion barrier in the gel. Mechanical testing indicated that the compressive strength at failure (σf) and elastic modulus (E) changed linearly with the amount of silicon alkoxide used in the gel composition. Measurement of naphthalene biodegradation by encapsulated cells indicated that the gel maintained cytocompatibility at lower levels of alkoxide. However, significant loss in activity was observed due to methanol formation during hydrolysis at high alkoxide concentrations, as measured by FTIR spectroscopy. The silica gel with the highest amount of alkoxide (without toxicity from methanol) had a biodegradation rate of 285 ± 42 nmol/L‐s, σf = 652 ± 88 kPa, and E = 15.8 ± 2.0 MPa. Biodegradation was sustained for 1 month before it dropped below 20% of the initial rate. In order to improve the diffusion through the gel, polyvinyl alcohol (PVA) was used as a porogen and resulted in a 48 ± 19% enhancement in biodegradation, but it impacted the mechanical properties negatively. This is the first report studying how the silica composition affects biodegradation of naphthalene by Pseudomonas sp. NCIB 9816‐4 and establishes a foundation for future studies of aromatic hydrocarbon biodegradation for industrial application. Biotechnol. Bioeng. 2016;113: 513–521. © 2015 Wiley Periodicals, Inc.
Traits of selected Clostridium strains for syngas fermentation to ethanol
Authors: Martin Michael E. , Richter Hanno , Saha Surya , Angenent Largus T.
Published: September 2015

Syngas fermentation is an anaerobic bioprocess that could become industrially relevant as a biorefinery platform for sustainable production of fuels and chemicals. An important prerequisite for commercialization is adequate performance of the biocatalyst (i.e., sufficiently high production rate, titer, selectivity, yield, and stability of the fermentation). Here, we compared the performance of three potential candidate Clostridium strains in syngas‐to‐ethanol conversion: Clostridium ljungdahlii PETC, C. ljungdahlii ERI‐2, and Clostridium autoethanogenum JA1‐1. Experiments were conducted in a two‐stage, continuously fed syngas‐fermentation system that had been optimized for stable ethanol production. The two C. ljungdahlii strains performed similar to each other but different from C. autoethanogenum. When the pH value was lowered from 5.5 to 4.5 to induce solventogenesis, the cell‐specific carbon monoxide and hydrogen consumption (similar rate for all strains at pH 5.5), severely decreased in JA1‐1, but hardly in PETC and ERI‐2. Ethanol production in strains PETC and ERI‐2 remained relatively stable while the rate of acetate production decreased, resulting in a high ethanol/acetate ratio, but lower overall productivities. With JA1‐1, lowering the pH severely lowered rates of both ethanol and acetate production; and as a consequence, no pronounced shift to solventogenesis was observed. The highest overall ethanol production rate of 0.301 g · L−1 · h−1 was achieved with PETC at pH 4.5 with a corresponding 19 g/L (1.9% w/v) ethanol concentration and a 5.5:1 ethanol/acetate molar ratio. A comparison of the genes relevant for ethanol metabolism revealed differences between C. ljungdahlii and C. autoethanogenum that, however, did not conclusively explain the different phenotypes. Biotechnol. Bioeng. 2016;113: 531–539. © 2015 Wiley Periodicals, Inc.
Postoperative vocal fold palsy in patients undergoing thyroid surgery with continuous or intermittent nerve monitoring
Authors: Schneider R , Sekulla C , Machens A , Lorenz K , Nguyen Thanh P , Dralle H
Published: September 2015

Background

Continuous monitoring of electromyographic (EMG) amplitudes of the vocal muscles detects impending injury of the recurrent laryngeal nerve (RLN) during thyroid operations earlier than intermittent EMG monitoring. This may alert the surgeon to stop a manoeuvre causing stretching or pressure on the RLN, with better recovery of nerve function.

Methods

Patients with intact preoperative RLN function who underwent thyroid surgery for benign disease between January 2011 and September 2014 under continuous intraoperative nerve monitoring (CIONM) or intermittent intraoperative nerve monitoring (IIONM) were included in this observational study conducted at a tertiary surgical centre. For CIONM, combined EMG events indicative of imminent nerve injury were defined as an EMG amplitude decrease of 50 per cent or more and a latency increase of 10 per cent relative to baseline values. The rates of early and permanent palsy for the two groups of patients were compared.

Results

There were 1526 patients, 788 of whom (1314 nerves at risk) underwent thyroid surgery using CIONM and 738 (965 nerves at risk) had IIONM. With the use of CIONM, 63 (82 per cent) of 77 combined events were reversible during the operation. No permanent vocal fold palsy occurred with CIONM, whereas four unilateral permanent vocal fold palsies (0·4 per cent) were diagnosed after IIONM (P = 0·019).

Conclusion

Operation with CIONM resulted in fewer permanent vocal fold palsies compared with IIONM after thyroid surgery in patients with benign disease.