bluuebunny/crossref_metadata_2025 huggingface dataset:
Processing, structure, and properties of multiwalled carbon nanotube–poly(phenylene sulfide) composite fibers
Authors: Zeng Luxian , Mou Hao , Qiao Yunyun , Chen Gong , Xu Jianjun , Liu Pengqing
Published: November 2016

To improve the processability and properties of the poly(phenylene sulfide) (PPS) fibers at room temperature and high temperatures, a series of composite fibers based on PPS and multiwalled carbon nanotubes were prepared by melt spinning. We researched the processability with a high‐pressure capillary rheometer, and the properties of the composite fibers were investigated in detail by scanning electron microscopy, differential scanning calorimetry, fiber sonic velocity measurement, and single‐fiber strength testing. The results show that the carbon nanotubes (CNTs) had good interfacial adhesion with PPS and dispersed homogeneously in the PPS matrix. When the shear rate was higher than 500 s−1, the oriented CNTs induced the orientation of PPS molecular chains; this resulted in a decline in the apparent viscosity and an increase in the orientation degree of the molecular chains. Meanwhile, the CNTs acted as nucleating agents to effectively improve the crystallization of PPS. The strength of the fibers at room temperature were improved by 28.8% after the addition of 0.2% CNTs, and the initial modulus was also significantly enhanced. The strength retention at 160 °C was promoted from 60.58 to 88.32% with the addition of 1.0% CNTs. The shrinking percentage decreased to almost zero from higher than 15%; this suggested that the CNTs could efficiently improve the dimensional stability at high temperatures. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44609.
Dielectric, mechanical and transport properties of bisphenol A polycarbonate/graphene nanocomposites prepared by melt blending
Authors: Oyarzabal Andrea , Cristiano‐Tassi Antonella , Laredo Estrella , Newman Dinorah , Bello Alfredo , Etxeberría Agustín , Eguiazabal José Ignacio , Zubitur Manuela , Mugica Agurtzane , Müller Alejandro J.
Published: November 2016

Nanocomposites based on polycarbonate (PC) and different amounts of untreated graphene nanoplatelets (GnP) (from 1 to 7 wt %) were prepared by melt blending. The nanocomposites were thoroughly characterized employing the following techniques: broad band dielectric spectroscopy, thermally stimulated depolarization currents, differential scanning calorimetry, tensile testing, dynamic mechanical thermal analysis, and water vapor, carbon dioxide and oxygen permeability measurements. The presence of a MWS relaxation mode indicated the accumulation of electrical charges trapped at the interfaces of the polycarbonate with graphene 2D platelets. The addition of GnP produced nanocomposite materials with enhanced mechanical and barrier properties. The melt mixed PC/graphene nanocomposites prepared here exhibit well‐balanced properties, even though unmodified graphene nanoplatelets were used. In addition, the nanocomposites were obtained by a single extrusion process, which is easily scalable for industrial applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44654.
Development and characterization of nanosoy‐reinforced dextran nanocomposite membranes
Authors: Singh Surabhi , Gupta Bhuvanesh
Published: November 2016

Crosslinked nanocomposite membranes were developed by in situ reaction of dextran and soy protein isolate nanoparticles (nanosoy). The formation of a covalent bond between the reducing end of dextran and the amine groups of nanosoy (NS) leads to the in situ crosslinking. The NS particles employed for this study were 5–15 nm in size, as observed in the high‐resolution transmission electron microscopy micrograph. Glycerol addition assisted in the plasticization of the membranes, thus improving their flexibility and handling features. The effect of polymer composition on the extent of crosslinking, morphology, and flexibility of the films was investigated. Field emission scanning electron microscopy and atomic force microscopy revealed that single‐phase, homogeneous membranes are obtained within a specific composition of dextran/NS/glycerol (D/NS/G). The degree of crosslinking was evaluated by Raman spectroscopy and gel content measurements. The crystallinity of the D/NS/G membranes was found to increase monotonically as the NS content in the blend increased. An increase in tensile strength and decrease in Young's modulus was observed with an increase in NS content up to 28%, due to the reinforcing effect of NS and the plasticizing effect of glycerol playing roles simultaneously in the system. The reinforcing effect of the NS assisted in the formation of high‐strength nanocomposite membranes. Furthermore, they were characterized to analyze their thermal behavior. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44655.
Role of bismuth oxide as a reinforcer on gamma shielding ability of unsaturated polyester based polymer composites
Authors: Ambika M. R. , Nagaiah N. , Suman S. K.
Published: November 2016

Unsaturated Polyester resin is reinforced with Bi2O3 up to 60% filler weight. The effect of bismuth oxide on gamma shielding ability of the composites is studied in terms of attenuation parameters using Ba‐133, Cs‐137, and Co‐60 gamma ray sources. The results reveal that, the shielding property of the composite material increases with increase in the filler concentration and decreases with energy. The HVL, TVL, and relaxation length of the composites are found to decrease with increase in the filler concentration. It is found that, the shielding ability of 60% filled polymer composite is comparable to that of barite at low energy. The above polymer composite performs well at all energies and can act as an excellent gamma radiation shield for low energies and also proved to be light weight when compared to the conventional shielding materials. Thus, the gamma shielding ability of the UP resin is enhanced due to the addition of Bi2O3. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44657.
Synthesis of a novel flame retardant containing phosphazene and triazine groups and its enhanced charring effect in poly(lactic acid) resin
Authors: Chen Yajun , Wang Wei , Liu Zhiqi , Yao Yuanyuan , Qian Lijun
Published: November 2016

A novel flame retardant heax‐[N,N′,N″‐tris‐(2‐amino‐ethyl)‐[1,3,5] triazine‐2,4,6‐triamine] cyclotriphosphazene (HTTCP) containing phosphazene and triazine groups was synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), solid‐state 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. HTTCP was applied to PLA matrix. The results of thermal gravimetric analysis (TGA), the limited oxygen index (LOI), and cone calorimeter test indicated that the HTTCP enhanced the thermal stability and flame retardant properties of PLA. When the mass fraction of HTTCP was 25 wt %, the PLA composite acquired a LOI value of 25.2% and the lower pk‐HRR at 290 kW/m2. The excellent flame retardancy of HTTCP was attributed to the group synergistic effect between phosphazene and triazine groups. However, when combined HTTCP with APP (the total amount remaining 25 wt %, the ratio of HTTP to APP are 1:1 and 1:2), high values of LOI (over 40%) and UL94 V‐0 rating without dripping reached simultaneously. Meanwhile, the heat release rate, total heat release and mass loss rate were all decreased dramatically. Scanning electron microscopy (SEM) demonstrated that HTTCP/APP system benefited to the formation of more intumescent, dense, compact char layer on the materials surface which could effectively prevent the underlying material from degradation during burning. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44660.
Degradation of radiation exposed polymethacrylamide (Rohacell® 31) foam used in composite hardware
Authors: Zaldivar R. J. , Labatete‐Goeppinger A. , Easton M. P. , Patel D. N.
Published: November 2016

Rohacell® foam is a critical structural component used to fabricate composite hardware for space applications. The effect of radiation exposure on Rohacell® 31 HFHT has been evaluated to determine the degree of chemical and mechanical degradation that may occur in a space environment. A 60Co source was used for exposure levels ranging from 0 to 8 Mrad. Tensile tests showed significant decreases of 50% in tensile strength and 75% decreases in failure strain, after only a 4‐Mrad exposure. However, the rate of degradation sharply decreased with additional exposure since crosslink density was more affected during the early stages of radiation exposure. Size exclusion chromatography and multiangle light scattering of the extracted material also provided evidence showing an increase in the concentration of lower molecular weight (Mw) fragments after exposure. The average Mw of the extracted material dropped by two orders of magnitude from the control to the 5‐Mrad specimens, however changes in Mw between the 5‐ and 8‐Mrad specimens only varied by 30% similar in trend to mechanical property data. LS analysis showed a structural conformation change from a heavily branched network to a more linear conformation. Dynamic mechanical analysis exhibited increases in the peak height and breadth of the tan δ curve with radiation dose. These increases in damping are a result of chain scission which results in increased segmental motion caused by decreases in the degree of crosslinking within the polymer structure. Gas chromatography–mass spectrometry was used to probe the potential sites of radiation susceptibility within the PMI polymer structure and are discussed. The radiation susceptibility of this polymeric material should be properly evaluated when utilizing this material for space applications since end of life conditions may vary significantly from beginning of life mechanical and thermal behavior. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44670.
Green composites of poly(3‐hydroxybutyrate) and curaua fibers: Morphology and physical, thermal, and mechanical properties
Authors: Scalioni Lucas V. , Gutiérrez Miguel C. , Felisberti Maria I.
Published: November 2016

In this article, we report the morphology and thermal, mechanical and physical properties of poly(3‐hydroxybutyrate) (PHB)/curaua composites containing triethyl citrate (TEC) as the plasticizer. The composites were prepared by mechanical mixing using pristine and chemically treated fibers (10 wt %) and TEC (30 wt %) and characterized by differential scanning calorimetry, dynamic mechanical analysis, X‐ray diffraction, small angle X‐ray scattering, polarized optical microscopy, scanning electron microscopy, tensile tests, impact resistance test, thermodilatometry, and thermal conductivity measurements. The curaua fibers acted as nucleating agent and strongly influenced the morphology of the crystalline phase of PHB, increasing the lamella thickness, decreasing the crystal size and inducing spherulite–axialite transition. These characteristics of the PHB crystalline phase determined all the properties of the composites. The tensile properties of the composites were comparable with those of neat PHB, while the impact resistance of composites was comparable with that of plasticized PHB. The higher heat capacity and thermal expansion coefficient and the lower thermal conductivity of the composites compared with neat PHB reflect the morphological changes in the PHB crystalline phase. The strategy of developing a green polymeric material from ecofriendly components exhibiting a good balance of properties by combining curaua fibers, TEC, and PHB was successful. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44676.
Thermal, mechanical, and acoustic properties of silica‐aerogel/UPVC composites
Authors: Eskandari Navid , Motahari Siamak , Atoufi Zhale , Hashemi Motlagh Ghodratollah , Najafi Mohammad
Published: November 2016

The properties of silica‐aerogel/UPVC composites have been investigated with emphasis on sound and heat insulation. UPVC is a material of construction for window profiles and drainage pipes. Hydrophobic silica aerogels were synthesized using silicate sodium as a precursor through a two‐step sol–gel process. The physical and textural properties of the synthesized silica aerogels such as density, surface area, and particle size were analyzed using SEM and BET analysis. Then, the synthesized aerogels were mixed with Unplastisized Polyvinyl Chloride (UPVC) compound at five different weight ratios in an internal mixer to find out the effects of silica aerogels on the thermal, mechanical, and acoustical characteristics. The prepared UPVC/aerogel composites were characterized for tensile properties, impact strength, hardness, Vicat softening temperature, thermal conductivity, sound absorption, and sound transmission loss. The results revealed that adding silica aerogel in to the matrix of UPVC increases its hardness and softening temperature while decreases impact strength. The thermal conductivity of UPVC was decreased by up to 50% using silica aerogel. The sound absorption property of UPVC was increased up to three times by using silica aerogels due to its high porosity. Silica aerogel increased the maximum sound transmission loss of UPVC in the low frequency range. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44685.
Spectrofluorimetric determination of certain adrenergic agonist drugs in their pure forms and pharmaceutical formulations: Content uniformity test application
Authors: Badr El‐Din Khalid M. , Attia Tamer Z.
Published: November 2016

A new, simple, sensitive and rapid spectrofluorimetric method has been developed for determination of certain adrenergic agonists such as isoxsuprine hydrochloride, ritodrine hydrochloride and etilefrine hydrochloride in their pure forms and pharmaceutical dosage forms. The method depends on micellar enhancement of the native fluorescence of investigated drugs by using 2% w/v sodium dodecyl sulfate (SDS) as an anionic surfactant. The enhanced fluorescence intensity of investigated drugs was measured at 305 nm after excitation at 278 nm. The interaction of studied drugs with SDS was studied, and the enhanced fluorescence intensity was exploited to develop an assay method for the determination of investigated drugs. The relative fluorescence intensity–concentration plots were rectilinear over the range 0.15–3.00 μg ml−1, with low quantification limits of 0.132, 0.123 and 0.118 μg mL−1 for isoxsuprine, ritodrine and etilefrine, respectively. The proposed method was successfully applied for determination of studied drugs in their pharmaceutical formulations. Moreover, the high sensitivity of the proposed method allows performing the content uniformity testing of the studied drugs in their tablets by using the official United States Pharmacopeia (USP) guidelines. Statistical comparisons of the results with those of the reported methods revealed excellent agreement and indicated no significant difference in accuracy and precision.
Sandwich–like Structure of Carbon Fluoride/Graphene Oxide/Polyacrylonitrile Cathode for Lithium and Sodium Batteries
Authors: Liu Wen , Zhan Bin‐Xin , Shi Bin , Li Yong , Guo Rui , Pei Hai‐Juan , Xie Jing‐Ying
Published: November 2016

Carbon fluoride/graphene oxide/polyacrylonitrile (CFx/GO/PAN, denoted as CGP) electrodes are prepared for lithium primary and sodium secondary batteries. The introduction of GO sheets and PAN built a sandwich‐like structure. The rate performances of Li/CGP batteries verify that PAN and GO materials have negligible effects on the electrochemical properties of lithium primary batteries. In Na/CGP batteries, GO sheets have more defects to facilitate sodium ions transfer and offer more active sites for NaF deposition and decomposition. Meanwhile, the GO network coating of the CFx particles confines active fluorine during the cycles. Cubic and nanoscale discharge products of NaF form both on the surface of CFx particles and the GO sheets, respectively. Na/CGF batteries achieve an initial discharge capacity of 507.0 mAh g−1 and a voltage polarization of 0.75 V, except in the first cycle. These results demonstrate that CGP electrodes with a sandwich‐like structure have favorable electrochemical properties, resulting in the synergetic effect of GO sheets and PAN.
Structural Basis for the KlenTaq DNA Polymerase Catalysed Incorporation of Alkene‐ versus Alkyne‐Modified Nucleotides
Authors: Hottin Audrey , Betz Karin , Diederichs Kay , Marx Andreas
Published: November 2016

Efficient incorporation of modified nucleotides by DNA polymerases is essential for many cutting‐edge biomolecular technologies. The present study compares the acceptance of either alkene‐ or alkyne‐modified nucleotides by KlenTaq DNA polymerase and provides structural insights into how 7‐deaza‐adenosine and deoxyuridine with attached alkene‐modifications are incorporated into the growing DNA strand. Thereby, we identified modified nucleotides that prove to be superior substrates for KlenTaq DNA polymerase compared with their natural analogues. The knowledge can be used to guide future design of functionalized nucleotide building blocks.
A convenient and validated enantiomer separation of chiral aliphatic amines as nitrobenzoxadiazole derivatives on polysaccharide‐derived chiral stationary phases under simultaneous ultraviolet and fluorescence detection
Authors: Adhikari Suraj , Kang Jong Seong , Lee Wonjae
Published: November 2016

A convenient method using a fluorogenic agent, 4‐chloro‐7‐nitro‐1,2,3‐benzoxadiazole (NBD‐Cl), was developed for enantiomer separation of chiral aliphatic amines including amino alcohols by normal high‐performance liquid chromatography. The enantiomer separation of chiral aliphatic amines as NBD derivatives was performed on six covalently bonded and four coated‐type polysaccharide‐derived chiral stationary phases (CSPs) under simultaneous ultraviolet (UV) and fluorescence detection (FLD). Among the covalently bonded CSPs, Chiralpak IE showed the best enantiomer separation for most analytes. The other CSPs also showed good enantioselectivity except for Chiralpak IB. On the other hand, Chiralpak AD‐H and Amylose‐1 generally exhibited better enantiomer separation of NBD derivatized chiral amines among the coated CSPs. The developed analytical technique was also applied to determine the optical purity of commercially available (R)‐ and (S)‐leucinol; the impurity was found to be 0.06%. The developed method was validated and proved to be an accurate, precise, sensitive, and selective method suitable for separation of chiral aliphatic amines as NBD derivatives under simultaneous UV and FLD.
Differential in radiosensitizing potency of enantiomers of the fatty acid synthase inhibitor C75
Authors: Rae Colin , Babich John W. , Mairs Robert J.
Published: November 2016

The elevated activity of fatty acid synthase has been reported in a number of cancer types. Inhibition of this enzyme has been demonstrated to induce cancer cell death and reduce tumor growth. In addition, the fatty acid synthase inhibitor drug C75 has been reported to synergistically enhance the cancer‐killing ability of ionizing radiation. However, clinical use of C75 has been limited due to its producing weight loss, believed to be caused by alterations in the activity of carnitine palmitoyltransferase‐1. C75 is administered in the form of a racemic mixture of (−) and (+) enantiomers that may differ in their regulation of fatty acid synthase and carnitine palmitoyltransferase‐1. Therefore, we assessed the relative cancer‐killing potency of different enantiomeric forms of C75 in prostate cancer cells. These results suggest that (−)‐C75 is the more cytotoxic enantiomer and has greater radiosensitizing capacity than (+)‐C75. These observations will stimulate the development of fatty acid synthase inhibitors that are selective for cancer cells and enhance the tumor‐killing activity of ionizing radiation, while minimizing weight loss in cancer patients.
Monoamine Oxidase Inhibitory Activity: Methyl‐ versus Chlorochalcone Derivatives
Authors: Mathew Bijo , Uçar Gülberk , Mathew Githa Elizabeth , Mathew Sincy , Kalatharakkal Purapurath Praseedha , Moolayil Fasil , Mohan Smrithy , Varghese Gupta Sheeba
Published: November 2016

Numerous studies have shown that chalcones are promising scaffolds for the development of new monoamine oxidase‐B (MAO‐B) inhibitors. As a continuation of our ongoing research into the development of reversible human MAO‐B (hMAO‐B) inhibitors, two series of twenty chalcones containing electron‐donating and electron‐withdrawing substituents were synthesized. All compounds were found to be competitive, selective, and reversible inhibitors of hMAO‐B except (2E)‐1‐(4‐methylphenyl)‐3‐(4‐nitrophenyl)prop‐2‐en‐1‐one (P7) and (2E)‐1‐(4‐chlorophenyl)‐3‐(4‐nitrophenyl)prop‐2‐en‐1‐one (P17), which were found to be selective inhibitors of hMAO‐A. The most potent hMAO‐B inhibitor, (2E)‐1‐(4‐chlorophenyl)‐3‐(4‐ethylphenyl)prop‐2‐en‐1‐one (P16), showed a Ki value of 0.11±0.01 μm. Molecular docking simulations were carried out to identify the hypothetical binding mode for the most potent compounds in the active sites of hMAO‐A and B. The ability of the compounds to cross the blood–brain barrier was assessed by parallel artificial membrane permeability assay (PAMPA). Additionally, the most potent hMAO‐B inhibitor P16 showed no toxicity in cultured hepatic cells at concentrations of 5 and 25 μm.
Salt Templating with Pore Padding: Hierarchical Pore Tailoring towards Functionalised Porous Carbons
Authors: Kumar K. Vasanth , Gadipelli Srinivas , Preuss Kathrin , Porwal Harshit , Zhao Tingting , Guo Zheng Xiao , Titirici Maria‐Magdalena
Published: November 2016

We propose a new synthetic route towards nanoporous functional carbon materials based on salt templating with pore‐padding approach (STPP). STPP relies on the use of a pore‐padding agent that undergoes an initial polymerisation/ condensation process prior to the formation of a solid carbon framework. The pore‐padding agent allows tailoring hierarchically the pore‐size distribution and controlling the amount of heteroatom (nitrogen in this case) functionalities as well as the type of nitrogen (graphitic, pyridinic, oxides of nitrogen) incorporated within the carbon framework in a single‐step‐process. Our newly developed STPP method offers a unique pathway and new design principle to create simultaneously high surface area, microporosity, functionality and pore hierarchy. The functional carbon materials produced by STPP showed a remarkable CO2/N2 selectivity. At 273 K, a carbon with only micropores offered an exceptionally high CO2 adsorption capacity whereas a carbon with only mesopores showed promising CO2‐philicity with high CO2/N2 selectivity in the range of 46–60 %, making them excellent candidates for CO2 capture from flue gas or for CO2 storage.
Plasmablastic lymphoma mimicking carcinomatosis: A case report and review of the literature
Authors: Olofson Andrea M. , Loo Eric Y. , Hill Paul A. , Liu Xiaoying
Published: November 2016

First identified as a distinct disease entity in HIV‐positive patients, plasmablastic lymphoma is a rare aggressive disease which arises predominantly in men and is associated with immunodeficiency of all causes. Although its exact etiology is poorly understood, Epstein–Barr virus infection and MYC gene aberrations have been implicated in its development in both HIV‐positive and HIV‐negative patients. The disease typically involves extranodal sites with a predilection for the oral cavity but may occur in other locations. Here we present a case of plasmablastic lymphoma diffusely involving the omentum and peritoneal cavity of an immunocompetent woman, clinically mimicking an ovarian carcinomatosis. To the best of our knowledge, this is the first case in which plasmablastic lymphoma has presented as peritoneal lymphomatosis. Diagn. Cytopathol. 2017;45:243–246. © 2016 Wiley Periodicals, Inc.
Substrate‐Selective Olefin Hydrogenation with a Cavitand‐Based Bis(N‐anisyl iminophosphorane)
Authors: Chavagnan Thierry , Bauder Claude , Sémeril David , Matt Dominique , Toupet Loïc
Published: November 2016

A distally‐substituted resorcin[4]arene cavitand equipped with two remote N‐anisyl‐imino‐phosphoranyl (AIP) units has been synthesised and assessed in the competitive hydrogenation of α‐olefins (rhodium catalyst). A substrate‐selectivity factor of 39.2 in favour of the linear olefin was observed after 1 h in the reduction of stoichiometric amounts of hex‐1‐ene and 3‐ethyl‐pent‐1‐ene. The catalyst was also shown to be suitable for the regioselective reduction of a compound that has two double bonds in different steric environments. The remarkable olefin discrimination probably arises from the ability of the ligand to generate a cavity‐capping N,O‐chelator involving both AIP groups. Chelate formation positions the reactive metal sites inside the receptor moiety, the restricted size of which may retard the coordination of larger α‐olefins. The results of this study encourage the further development of cavitands as shape‐selective catalysts.
A Cu‐Catalysed Radical Cross‐Dehydrogenative Coupling Approach to Acridanes and Related Heterocycles
Authors: Hurst Timothy E. , Taylor Richard J. K.
Published: November 2016

The synthesis of acridanes and related compounds through a Cu‐catalysed radical cross‐dehydrogenative coupling of simple 2‐[2‐(arylamino)aryl]malonates is reported. This method can be further streamlined to a one‐pot protocol involving the in situ fomation of the 2‐[2‐(arylamino)aryl]malonate by α‐arylation of diethyl malonate with 2‐bromodiarylamines under Pd catalysis, followed by Cu‐catalysed cyclisation.
Flavin‐Mediated Visible‐Light [2+2] Photocycloaddition of Nitrogen‐ and Sulfur‐Containing Dienes
Authors: Jirásek Michael , Straková Karolína , Neveselý Tomáš , Svobodová Eva , Rottnerová Zdeňka , Cibulka Radek
Published: November 2016

The [2+2] photocycloaddition mediated by 1‐butyl‐3‐methyl‐7,8‐dimethoxyalloxazine (1) has been found to be an effective tool for cyclising ω‐phenyl‐ and ω,ω′‐diphenyl‐4‐aza‐1,6‐heptadienes, in which the nitrogen atom is protected by acylation or quaternisation, towards the synthesis of a variety of phenyl‐ and diphenyl‐3‐azabicyclo[3.2.0]heptanes and their corresponding quaternary salts. Thia derivatives, with the sulfur atom in the form of a sulfone group, underwent an analogous cyclisation. Advantageously, visible light (400 nm) was used for the cycloadditions in the presence of 1, in contrast to the previously described procedures affording azabicyclo[3.2.0]heptanes by using UV irradiation. Practical applications are demonstrated through the synthesis of bicyclic quaternary ammonium salts, 6‐phenyl‐azabicyclo[3.2.0]heptanes known to exhibit biological activity or chiral spiro ammonium salts. Flavin 1 was also found to promote the efficient E→Z isomerisation of electron‐rich cinnamyl derivatives to produce mixtures enriched with the Z isomer (with Z/E ratios of up to 77:23).
A general approach to testing for pleiotropy with rare and common variants
Authors: Lutz Sharon M. , Fingerlin Tasha E. , Hokanson John E. , Lange Christoph
Published: November 2016

Through genome‐wide association studies, numerous genes have been shown to be associated with multiple phenotypes. To determine the overlap of genetic susceptibility of correlated phenotypes, one can apply multivariate regression or dimension reduction techniques, such as principal components analysis, and test for the association with the principal components of the phenotypes rather than the individual phenotypes. However, as these approaches test whether there is a genetic effect for at least one of the phenotypes, a significant test result does not necessarily imply pleiotropy. Recently, a method called Pleiotropy Estimation and Test Bootstrap (PET‐B) has been proposed to specifically test for pleiotropy (i.e., that two normally distributed phenotypes are both associated with the single nucleotide polymorphism of interest). Although the method examines the genetic overlap between the two quantitative phenotypes, the extension to binary phenotypes, three or more phenotypes, and rare variants is not straightforward. We provide two approaches to formally test this pleiotropic relationship in multiple scenarios. These approaches depend on permuting the phenotypes of interest and comparing the set of observed P‐values to the set of permuted P‐values in relation to the origin (e.g., a vector of zeros) either using the Hausdorff metric or a cutoff‐based approach. These approaches are appropriate for categorical and quantitative phenotypes, more than two phenotypes, common variants and rare variants. We evaluate these approaches under various simulation scenarios and apply them to the COPDGene study, a case‐control study of chronic obstructive pulmonary disease in current and former smokers.
Predictive factors and treatment outcome of laryngeal carcinoma recurrence
Authors: Haapaniemi Aaro , Väisänen Janne , Atula Timo , Alho Olli‐Pekka , Mäkitie Antti , Koivunen Petri
Published: November 2016

Background

Up to 30% of patients with laryngeal squamous cell carcinoma (SCC) present with recurrence after treatment. We analyzed factors associated with the risk of cancer recurrence and prognosis after recurrence.

Methods

A nationwide laryngeal SCC cohort from Finnish university hospitals during 2001 to 2005 with initial successful therapy (n = 316) was analyzed.

Results

Laryngeal SCC recurred in 22% of patients. The median time to recurrence was 9 months, with 90% occurring within 36 months after treatment. The World Health Organization (WHO) performance status >0, neck metastasis at presentation, and nonsurgical treatment were independent prognostic factors for recurrence. Patients with local recurrence had a 5‐year overall survival (OS) of 53% compared with 5% in patients with regional/distant recurrences. OS for glottic and nonglottic laryngeal SCC recurrence was 45% and 0%, respectively.

Conclusion

The type of treatment affected the risk of recurrence in this retrospective series. Local recurrences carried a chance for successful salvage treatment. Routine follow‐up beyond 36 months remains controversial. © 2016 Wiley Periodicals, Inc. Head Neck 39: 555–563, 2017
Investigation of the effects of kisspeptin‐10 in methionine‐induced lipid peroxidation in testicle tissue of young rats
Authors: Akkaya Hatice , Eyuboglu Signem , Erkanlı Senturk Gozde , Yilmaz Bayram
Published: November 2016

Disruption of the balance oxidants, antioxidants cause various pathophysiological conditions such as lipid peroxidation, protein degradation, or DNA damage. We have examined possible effects of kisspeptin‐10 on the structural damage produced by methionine‐induced lipid peroxidation in testicle tissue of young rats. Kisspeptin‐10 did not significantly affect spermatogenic cells in seminiferous tubules. Testosterone levels decreased in the methionine group as compared with the control group but without statistical significance. Luteinizing hormone levels decreased in the methionine group as compared with the control group (P < 0.001). Catalase enzyme activity increased in the kisspeptin‐10 group (P < 0.01) as compared with the other groups. Catalase mRNA expression was decreased in the methionine group as compared with the kisspeptin group (P < 0.001). Total superoxide dismutase enzyme activity and superoxide dismutase mRNA expression were increased in the kisspeptin group as compared with the methionine group (P < 0.05). In conclusion, kisspeptin treatment may protect the structure of spermatogenic cells against methionine‐induced damage.
Characterizing Graphs with Crossing Number at Least 2
Authors: Arroyo Alan , Richter R. Bruce
Published: November 2016

Our main result includes the following, slightly surprising, fact: a 4‐connected nonplanar graph G has crossing number at least 2 if and only if, for every pair of edges having no common incident vertex, there are vertex‐disjoint cycles in G with one containing e and the other containing f.
Is nonabsorbable nasal packing after septoplasty essential? A meta‐analysis
Authors: Kim Jong Seung , Kwon Sam Hyun
Published: November 2016

Objectives

Septoplasty is one of the most frequently performed rhinologic surgeries. Complications include nasal bleeding, pain, headache, septal hematoma, synechia, infection, residual septal deviation, and septal perforation. In this study, we aimed to compare complication rates among patients according to packing method.

Methods

We performed a literature search using PubMed, Embase, and the Cochrane Library through August 2016. Our systematic review followed Preferred Reporting Items for Systematic Reviews and Meta‐analyses guidelines. Random effect models were used to calculate risk differences and risk ratio with 95% confidence intervals (CIs). Cases referred to the nonpacking group included patients treated with transseptal sutures or septal splints. Cases referred to as the packing group included patients treated with nonabsorbable packing such as Merocel or gauze.

Results

Our search included 20 randomized controlled trials (RCTs) with a total of 1,321 subjects in the nonpacking group and 1,247 subjects in the packing group. There were no significant differences between packing methods regarding bleeding, hematoma, perforation, infection, and residual septal deviation. The risk differences of postoperative pain, headache, and postoperative synechia were −0.50 [95% CI: −0.93 to −0.07, P = .02], −0.42 [95% CI: −0.66 to −0.19, P = .0004], and −0.03 [95% CI: −0.06 to −0.01, P = .01], respectively.

Conclusions

Nonabsorbable nasal packing is no more effective than treatments without packing after septoplasty. Septal splints and transseptal sutures reduce postoperative pain, headache, and synechia.

Level of Evidence

1B Laryngoscope, 127:1026–1031, 2017
Spatial Distribution and Management Zones for Sulphur and Micronutrients in Shiwalik Himalayan Region of India
Authors: Shukla Arvind K. , Sinha Nishant K. , Tiwari Pankaj K. , Prakash Chandra , Behera Sanjib K. , Lenka Narendra K. , Singh Vinod K. , Dwivedi Brahma S. , Majumdar Kaushik , Kumar Anil , Srivastava Prakash C. , Pachauri Satya P. , Meena Mahesh C. , Lakaria Brij L. , Siddiqui Sahab
Published: November 2016

Agricultural land degradation due to nutrient deficiencies is a threat to agricultural sustainability. As nutrients availability is influenced by soil heterogeneity, climatic conditions and anthropogenic activities; hence, delineation of nutrient management zones (MZs) based on spatial variability could be an effective management option at regional scale. Thus, the present study was carried out to delineate MZs in the Shiwalik Himalayan region of India by capturing spatial variability of soil properties and secondary and micronutrients status because of the emerging nutrient deficiencies. For the study, a total of 2575 geo‐referenced representative surface (0–15 cm depth) soil samples were collected from the study region covering an area of 53,483 km2. The soils were analysed for pH, electrical conductivity, soil organic carbon, available sulphur (S) and micronutrients (Zn, Fe, Cu, Mn, B and Mo) concentrations. There was a wide variation in soil properties with coefficient of variation values of 14 (for pH) to 86% for available Mo. Geostatistical analysis revealed spherical, Gaussian, exponential, stable, circular and K‐Bessel best‐fit models for soil properties. Most of the soil properties were having moderate spatial dependence except soil pH and S (strong spatial dependence) and Zn (weak spatial dependence). About 49%, 10%, 2%, 13%, 11%, 12% and 8% area of the study region were found to be deficient (including acute and marginal deficiency) in S, Zn, Fe, Cu, Mn, B and Mo, respectively. The principal component analysis and fuzzy c‐mean clustering were performed to develop the MZs. Four principal components with eigenvalues greater than 1 and accounting 65·4% of total variance were retained for further analysis. On the basis of fuzzy performance index and normalized classification entropy, four potential MZs were identified. Analysis of variance confirmed the heterogeneity in most of the studied soil properties among the MZs. The study indicated that the methodology of delineating MZs can be effectively used in site‐specific S and micronutrients management in the Shiwalik Himalayan region of India. Copyright © 2016 John Wiley & Sons, Ltd.
Structure and Properties of New sPEEK/Zirconia/Protic Ionic Liquid Membranes for Fuel Cell Application
Authors: Batalha João Arthur Ferreira Lunau , Dahmouche Karim , Sampaio Rômulo Batista , de Souza Gomes Ailton
Published: November 2016

Hybrid organic–inorganic membranes based on sulfonated poly(ether ether ketone) (sPEEK), zirconium oxide, and the protic ionic liquid (PIL) diethylmethylamine triflate ([dema][TfOH]) have been synthesized. Their structure has been investigated by X‐ray diffraction and small‐angle X‐ray scattering and correlated to their electrical and thermomechanical properties. The membranes present good mechanical and chemical stabilities, as well as thermal stability over 300 °C. Zirconia contents up to 5 wt% (10 wt% PIL) lead to the formation of isolated zirconia‐rich aggregates dispersed in the polymer matrix, constituted of spatially correlated zirconia nanoparticles. This segregation of zirconia species in nanodomains, interacting with sulfonic groups of sPEEK, inhibits conductivity. Differently, zirconia content of 6 wt% (10 wt% PIL) induces a conductivity much higher than pristine sPEEK, due to the formation of an extended fractal structure in the whole sample, constituted of connected zirconia‐rich aggregates. Interaction of PIL molecules with the zirconia aggregates along this extended structure shall form new conducting channels for ion transport, favoring conductivity.

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Stimulus‐Responsive Nanoparticles and Associated (Reversible) Polymorphism via Polymerization Induced Self‐assembly (PISA)
Authors: Pei Yiwen , Lowe Andrew B. , Roth Peter J.
Published: November 2016

Polymerization‐induced self‐assembly (PISA) is an extremely versatile method for the in situ preparation of soft‐matter nanoparticles of defined size and morphologies at high concentrations, suitable for large‐scale production. Recently, certain PISA‐prepared nanoparticles have been shown to exhibit reversible polymorphism (“shape‐shifting”), typically between micellar, worm‐like, and vesicular phases (order–order transitions), in response to external stimuli including temperature, pH, electrolytes, and chemical modification. This review summarises the literature to date and describes molecular requirements for the design of stimulus‐responsive nano‐objects. Reversible pH‐responsive behavior is rationalised in terms of increased solvation of reversibly ionized groups. Temperature‐triggered order–order transitions, conversely, do not rely on inherently thermo‐responsive polymers, but are explained based on interfacial LCST or UCST behavior that affects the volume fractions of the core and stabilizer blocks. Irreversible morphology transitions, on the other hand, can result from chemical post‐modification of reactive PISA‐made particles. Emerging applications and future research directions of this “smart” nanoparticle behavior are reviewed.

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Fast and efficient free induction decay MR spectroscopic imaging of the human brain at 9.4 Tesla
Authors: Chadzynski Grzegorz L. , Bause Jonas , Shajan Gunamony , Pohmann Rolf , Scheffler Klaus , Ehses Philipp
Published: November 2016

Purpose

The purpose of this work was to develop a fast and efficient MRSI‐FID acquisition scheme and test its performance in vivo. The aim was to find a trade‐off between the minimal total acquisition time and signal‐to‐noise ratio of the acquired spectra.

Methods

Measurements were performed on a 9.4 Tesla system. Sequence optimization included redesign of water suppression, optimization of the sequence gradients, and improvement of the sampling efficiency by minimizing the read‐out time. This resulted in an acquisition time of 2:47 and 22:13 minutes for 2D (TR = 57 ms; 3‐mm in‐plane resolution) and 3D MRSI (TR = 57 ms; 16 slices; 3‐mm isotropic resolution), respectively.

Results

Despite strong T1 weighting and first‐order phase problems, it was possible to obtain spectra of an acceptable quality. The average line width calculated for the tCr peak across the entire field of view was 26.9 ± 9.6 Hz for 2D and 30.0 ± 11.3 Hz for 3D MRSI. In 3D measurements, the percent fraction of voxels fitted with Cramer‐Rao lower bounds below 10% was 53.3 ± 4.1%, 63.4 ± 8.4%, and 81.0 ± 2.9% for Glu, tCr, and tNAA, respectively.

Conclusion

Considering the typically long duration of high‐resolution MRSI, the proposed technique may be of interest for clinical applications and/or studies that focus on following the biochemistry of dynamic processes. Magn Reson Med 78:1281–1295, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Bromodomain and extraterminal protein inhibitors in pediatrics: A review of the literature
Authors: Jiménez Irene , Baruchel André , Doz François , Schulte Johannes
Published: November 2016

The last few years have seen the identification of pharmacologic approaches to target bromodomain and extraterminal (BET) proteins for cancer treatment. These proteins have an essential role in gene transcription regulation by binding acetylated lysine residues on histone tails, activating gene transcription. BET inhibitors have been tested in preclinical models including pediatric malignancies and several adult clinical trials are ongoing. Since the development of new drugs in pediatric cancer has long lagged behind programs for adults, the aim of this review is to show the importance of these therapies in pediatric malignancies to support their development in pediatric oncology/hematology.
PROMOTING SECONDARY TEACHERS’ WELL‐BEING AND INTENTIONS TO IMPLEMENT EVIDENCE‐BASED PRACTICES: RANDOMIZED EVALUATION OF THE ACHIEVER RESILIENCE CURRICULUM
Authors: Cook Clayton R. , Miller Faith G. , Fiat Aria , Renshaw Tyler , Frye Megan , Joseph Gail , Decano Polocarpio
Published: November 2016

Teaching is regarded as one of the most challenging yet rewarding professions. Moreover, research has shown that stress and burnout are likely to undermine teacher effectiveness and negatively impact their willingness and intentions to implement evidence‐based practices. The present study sought to contribute to a growing body of research implicating the importance of teacher well‐being by evaluating the efficacy of a theoretically based training that integrates several practices into a single program (e.g., mindfulness, values clarification, gratitude practices, sleep hygiene, etc.) that are designed to promote the well‐being of teachers—the ACHIEVER Resilience Curriculum (ARC). To evaluate the ARC, a randomized block controlled study was conducted with pre–post measurement. Results from the study indicated that, compared with an active control group, teachers who participated in the ARC experienced significantly better outcomes, characterized by medium effect sizes, including reductions in job‐related stress, improvements in teaching self‐efficacy, and stronger intentions to implement evidence‐based classroom practices. The implications of these findings for teacher preparation and professional development, along with the limitations of the study, are discussed.
MINDFULNESS GOES TO SCHOOL: THINGS LEARNED (SO FAR) FROM RESEARCH AND REAL‐WORLD EXPERIENCES
Authors: Semple Randye J. , Droutman Vita , Reid Brittany Ann
Published: November 2016

Mindfulness‐based curricula are being implemented in K‐12 schools across the nation. Many of these programs, although well considered and implemented, have little or no research support for their effectiveness. Recognizing the paucity of published research in this area, a sampling of school‐based programs currently being implemented in the schools is reviewed. The programs reviewed are Inner Explorer, Master Mind and Moment Program, Mindfulness and Mind‐Body Skills for Children, Mindful Schools, Resilient Kids, Still Quiet Place, Stress Reduction and Mindfulness Curriculum and Mindful Moment, and Wellness and Resilience Program. We offer a summary of research support for each program and discussion of unpublished, mostly qualitative indicators of feasibility, acceptability, efficacy, and effectiveness. Strengths and limitations of each program are described, along with suggestions for bolstering informative and useful research. We encourage researchers, educators, and mindfulness practitioners to work collaboratively to conduct rigorous program evaluations.
Influence of main chain on the phase behaviors of side‐chain liquid‐crystalline polymers with triphenylene mesogens of long alkyl tail substituents
Authors: Li Ping , Chen Sheng , Luo Hang , Zhang Dou , Zhang Hailiang
Published: November 2016

A series of side‐chain liquid‐crystalline polymers (SCLCPs) containing triphenylene mesogen, in which the long alkyl tail Tp connected directly with main chain, were synthesized successfully. The chemical structures of the monomers were confirmed by 1H NMR and mass spectrometry. The phase behaviors of polymers were investigated by a combination of techniques, including DSC, POM, 1D/2D WAXD, and SAXS. The experimental results suggested that the type of main chain played an important role in the LC phase structures of these polymers. Because of the steric effects of side chains and the coupling effects between the Tp moieties and the main chains, all the polymers exhibited columnar phase. However, the SCLCPs with poly(vinyl benzene methyl ether) or polynorbornene backbone displayed hexagonal columnar phase, while those with polyacrylate or polymethacrylate backbone presented columnar nematic phase, and the one with poly(vinyl benzoate) main chain showed rectangular columnar phase. Moreover, the clearing temperatures (Ti) changed with change in main chain. Especially, the Ti of the SCLCP with polymethacrylate backbone was above 300 °C. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 754–766
Structural, electronic and optical properties of famatinite and enargite Cu3SbS4 under pressure: A theoretical investigation
Authors: Li Jian , Han Xiuxun , Li Jiajia , Zhao Yun , Fan Changzeng
Published: November 2016

The structural, electronic and optical properties of Cu3SbS4 with different crystalline structures have been investigated by using the PBE generalised gradient approximation and hybrid functional method (HSE06) to density functional theory at ambient and high pressure. The calculated elastic constants and phonon dispersions reveal that both the famatinite and enargite phases are mechanically and dynamically stable, except for the cubic phase. The energy difference between famatinite and enargite is fairly small within the studied pressure range. Calculations on electronic band structure indicate that famatinite and enargite Cu3SbS4 are direct band gap materials with relatively low values of 0.39 and 0.32 eV, respectively, and the band gap increases with the increasing pressure. The optical properties calculations predict a blue‐shift in the absorption edges of famatinite and enargite in response to the applied pressure.