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Jing Li, Guocheng Song, Junrong Yu, Yan Wang, Jing Zhu, Zuming Hu
Solution blow spinning (SBS) is an innovative process for spinning micro/nanofibers. In this paper, polyamic acid (PAA) nanofibers were fabricated via a SBS apparatus and then imidized into polyimide (PI) nanofibers via thermal process. The morphology and diameter distributions of PAA nanofibers were determined by scanning electron microscope (SEM) and Image Tool software, the processing parameters, including PAA concentration, solution feeding rate, gas pressure, nozzle size, and receiving distance were investigated in details...
November 17, 2017: Nanomaterials
Alexander S Ivanov, Christina J Leggett, Bernard F Parker, Zhicheng Zhang, John Arnold, Sheng Dai, Carter W Abney, Vyacheslav S Bryantsev, Linfeng Rao
Amidoxime-functionalized polymeric adsorbents are the current state-of-the-art materials for collecting uranium (U) from seawater. However, marine tests show that vanadium (V) is preferentially extracted over U and many other cations. Herein, we report a complementary and comprehensive investigation integrating ab initio simulations with thermochemical titrations and XAFS spectroscopy to understand the unusually strong and selective binding of V by polyamidoximes. While the open-chain amidoxime functionalities do not bind V, the cyclic imide-dioxime group of the adsorbent forms a peculiar non-oxido V(5+) complex, exhibiting the highest stability constant value ever observed for the V(5+) species...
November 16, 2017: Nature Communications
Jiajing Feng, Wei Jiang, Zhaohui Wang
Rylene imide dyes have been among the most promising organic semiconducting materials for several years due to their remarkable optoelectronic properties and high chemical/thermal persistency. In the past decades, various spendid rylene imide dyes have been developed for optoelectronic devices, such as organic solar cells (OSCs) and organic field-effect transistors (OFETs). Recently, tremendous progress of perylene diimides (PDIs) and the analogues used in OSCs has been witnessed attributed to their ease of functionalization...
November 16, 2017: Chemistry, An Asian Journal
Gulsum Sayin Ozel, Mehmet Burak Guneser, Ozgur Inan, Ayce Unverdi Eldeniz
PURPOSE: Bacterial adhesion on provisional crown materials retained for a long time can influence the duration for which permanent prosthetic restorations can be healthily worn in the oral cavity. The aim of this study was to compare seven different commonly used provisional crown materials with regard to Streptococcus mutans and Candida albicans surface adhesion. MATERIALS AND METHODS: For each group, twenty specimens of the provisional fixed prosthodontic materials TemDent (Schütz), Imıdent (Imıcryl), Tab 2000 (Kerr), Structur Premium (Voco), Systemp (Ivoclar Vivadent), Acrytemp (Zhermack), and Takilon-BBF (Takilon) were prepared (diameter, 10...
October 2017: Journal of Advanced Prosthodontics
Carmela Santangelo, Rosaria Vari, Beatrice Scazzocchio, Patrizia De Sanctis, Claudio Giovannini, Massimo D'Archivio, Roberta Masella
Altered inflammatory response characterizes chronic immune-mediated inflammatory diseases (IMID) such as rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, systemic lupus erythematosus, and psoriasis. Accumulating evidence indicates that regular consumption of extra virgin olive oil (EVOO), the main source of fat in the Mediterranean diet, is associated with a reduced risk of developing chronic degenerative disorders such cardiovascular diseases, type 2 diabetes and cancer. The beneficial effects on health of EVOO have been attributed, besides to the monounsaturated fats content, to the presence of phenolic compounds that have antioxidant, anti-inflammatory and immunomodulatory properties...
November 13, 2017: Endocrine, Metabolic & Immune Disorders Drug Targets
Nicholas Pearce, E Stephen Davies, Raphael Horvath, Constance R Pfeiffer, Xue-Zhong Sun, William Lewis, Jonathan McMaster, Michael W George, Neil R Champness
Varying the degree of thionation of a series of naphthalene diimide (NDI) and naphthalic imide (NI) phenothiazine dyad systems affords a systematic approach for tuning the system's donor-acceptor energy gap. Each dyad was compared to model NDI/NI systems and fully characterised through single crystal X-ray diffraction, NMR, cyclic voltammetry, electron paramagnetic resonance (EPR), transient absorption spectroscopy (TA), time-resolved infra-red spectroscopy (TRIR) and DFT. The measurements reveal that thionation increases both electron affinity of the NDI/NI acceptor dyad component and accessibility of the singly or doubly reduced states...
November 15, 2017: Physical Chemistry Chemical Physics: PCCP
Slimane Merouani, Oualid Hamdaoui, Boumediene Haddad
In this work, a comparison between the temperatures/pressures within acoustic cavitation bubble in an imidazolium-based room-temperature ionic liquid (RTIL), 1-butyl-3-methylimidazolium bis(triflluoromethyl-sulfonyl)imide ([BMIM][NTf2]), and in water has been made for a wide range of cavitation parameters including frequency (140-1000kHz), acoustic intensity (0.5-1Wcm(-2)), liquid temperature (20-50°C) and external static pressure (0.7-1.5atm). The used cavitation model takes into account the liquid compressibility as well as the surface tension and the viscosity of the medium...
March 2018: Ultrasonics Sonochemistry
Luis E Camacho-Forero, Perla B Balbuena
The lithium metal anode is one of the key components of the lithium-sulfur (Li-S) batteries, which are considered one of the most promising candidates for the next generation of battery systems. However, one of the main challenges that have prevented Li-metal anodes from becoming feasible to be used in commercial batteries is the continuous decomposition of the electrolyte due to its high reactivity, which leads to the formation of solid-electrolyte interphase (SEI) layers. The properties of the SEI can dramatically affect the performance of the batteries...
November 14, 2017: Physical Chemistry Chemical Physics: PCCP
Florian Buchner, Jihyun Kim, Christiane Adler, Maral Bozorgchenani, Joachim Bansmann, R Jürgen Behm
The intercalation and deintercalation of lithium (Li) into / out of graphite(0001), which is a highly important process in Li-ion batteries, was investigated under ultrahigh vacuum conditions as a function of temperature, employing X-ray and ultraviolet photoelectron spectroscopy. Both the up-shifts of the core-level binding energy and the lowering of the work function ΔΦ reveal that heating of a monolayer of the battery-relevant ionic liquid (IL) 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide ([BMP](+)[TFSI](-)) adsorbed on lithiated graphite at 80 K to >230 K facilitates an accumulation of partially charged Li(δ+) atoms at the IL-graphite(0001) interface...
November 15, 2017: Journal of Physical Chemistry Letters
Anita Yadav, Siddharth Pandey
Ionic liquids, being composed of ions alone, may offer alternate pathways for molecular aggregation. These pathways could be controlled by the chemical structure of the cation and the anion of the ionic liquids. Intramolecular excimer formation dynamics of a bifluorophoric probe, 1,3-bis(1-pyrenyl)decane [1Py(10)1Py], where the fluorophoric pyrene moieties are separated by a long decyl chain, is investigated in seven different ionic liquids in 10 - 90 °C temperature range. The long alkyl separator allows for ample interaction with the solubilizing milieu prior to the formation of the excimer...
November 13, 2017: Journal of Physical Chemistry. B
Roman Elfgen, Oldamur Hollóczki, Barbara Kirchner
The structure-directing or template effect has been invoked several times for ionic liquids to explain the different outcome in material synthesis, namely, different scaffolds or geometrical arrangements with varying ionic liquids. It is obvious to assume that such an effect can originate from the most likely complex microstructure, being present within the ionic liquid itself. In that regard, ionic liquids have already been shown to undergo a nanosegregation into polar and nonpolar phases, which is commonly known and denoted as microheterogeneity...
November 13, 2017: Accounts of Chemical Research
Konstantinos Dimopoulos, Alexandra Søgaard Helbo, Helga Fibiger Munch-Petersen, Lene Sjö, Jesper Christensen, Lasse Sommer Kristensen, Fazila Asmar, Emil Hermansen, Casey O'Connel, Peter Gimsing, Gangning Liang, Kirsten Grønbaek
Thalidomide and its derivatives, lenalidomide and pomalidomide (also known as IMiDs), have significantly changed the treatment landscape of multiple myeloma, and the recent discovery of cereblon (CRBN) as their direct biological target has led to a deeper understanding of their complex mechanism of action. In an effort to comprehend the precise mechanisms behind the development of IMiD resistance and examine whether it is potentially reversible, we established lenalidomide- (-LR) and pomalidomide-resistant (-PR) human myeloma cell lines from two IMiD-sensitive cell lines, OPM2 and NCI-H929, by continuous culture in the presence of lenalidomide or pomalidomide for 4-6 months, until acquirement of stable resistance...
November 11, 2017: Molecular Oncology
Asma Iqbal, Naila Khalid, Humaira M Siddiqi, O Ok Park, Toheed Akhter
A series of fluorescent donor- acceptor (D-A) alternating copolyimides (P1, P2, P3 and P4) with 4-quinolin-8-yloxy linked triphenylamine main polymer chain have been synthesized by conventional polycondensation. All the synthesized co-polyimides were characterized by elemental, gel permeation chromatography and FTIR spectral analysis. These newly prepared PIs possess HOMO energy levels in range of - 4.74 to - 4.78 eV and have medium optical band gaps. The photoluminescence spectral analysis revealed blue to violet emission with appreciable efficiency with lower onset oxidation potentials suitable for the facile hole injection materials...
November 7, 2017: Journal of Fluorescence
Benjamin James Frogley, Lakshika Perera, L James Wright
The first examples of amino-substituted fused-ring metallabenzenes, the cationic iridabenzofuran [Ir(C7H4O{NH2-2}{OMe-7})(CO)(PPh3)2][O3SCF3] (5) and neutral analogue Ir(C7H4{NH2-2}{OMe-7})Cl(PPh3)2 (6), can be prepared by reduction of the corresponding nitro-substituted iridabenzofurans with zinc and concentrated hydrochloric acid. N-functionalised derivatives of 5 and 6 are formed through alkylation, sulfonylation or acylation. Thus, consecutive treatments with methyl triflate and base gives the corresponding trimethylammonium-substituted iridabenzofurans while sulfonamide derivatives are formed with p-toluenesulfonyl chloride...
November 7, 2017: Chemistry: a European Journal
Katharine L Harrison, Kevin R Zavadil, Nathan T Hahn, Xiangbo Meng, Jeffrey W Elam, Andrew Leenheer, Ji-Guang Zhang, Katherine L Jungjohann
To understand the mechanism that controls low-aspect-ratio lithium deposition morphologies for Li-metal anodes in batteries, we conducted direct visualization of Li-metal deposition and stripping behavior through nanoscale in situ electrochemical scanning transmission electron microscopy (EC-STEM) and macroscale-cell electrochemistry experiments in a recently developed and promising solvate electrolyte, 4 M lithium bis(fluorosulfonyl)imide in 1,2-dimethoxyethane. In contrast to published coin cell studies in the same electrolyte, our experiments revealed low Coulombic efficiencies and inhomogeneous Li morphology during in situ observation...
November 13, 2017: ACS Nano
Baobing Fan, Lei Ying, Peng Zhu, Feilong Pan, Feng Liu, Junwu Chen, Fei Huang, Yong Cao
A novel wide-bandgap conjugated copolymer based on an imide-functionalized benzotriazole building block containing a siloxane-terminated side-chain is developed. This copolymer is successfully used to fabricate highly efficient all-polymer solar cells (all-PSCs) processed at room temperature with the green-solvent 2-methyl-tetrahydrofuran. When paired with a naphthalene diimide-based polymer electron-acceptor, the all-PSC exhibits a maximum power conversion efficiency (PCE) of 10.1%, which is the highest value so far reported for an all-PSC...
November 7, 2017: Advanced Materials
Hirotaka Koga, Masaya Nogi, Akira Isogai
Functional molecules play a significant role in the development of high-performance composite materials. Functional molecules should be well dispersed (ideally dissolved) and supported within an easy-to-handle substrate to take full advantage of their functionality and ensure easy handling. However, simultaneously achieving the dissolution and support of functional molecules remains a challenge. Herein, we propose the combination of a nonvolatile ionic liquid and an easy-to-handle cellulose paper substrate for achieving this goal...
November 13, 2017: ACS Applied Materials & Interfaces
Ahmad Arabi Shamsabadi, Farzad Seidi, Mohammad Nozari, Masoud Soroush
In addition to possessing excellent chemical, mechanical and thermal stability, polyimides and polyetherimides have excellent solubility in many solvents, rendering them suitable for membrane preparation. In this paper, we report the synthesis and characterization of two new monomers [a pentiptycene-based dianhydride (PPDAn) and a pentiptycene imide-containing diamine (PPImDA)], and a pentiptycene-based polyimide [PPImDA-4, 4'-hexafluoroisopropylidene diphthalic anhydride (PPImDA-6FDA)]. The products are characterized using FTIR, 1H NMR, GPC, mass spectroscopy, XPS, TGA, DSC, BET, and XRD...
November 6, 2017: ChemSusChem
R A Marrie, R Walld, J M Bolton, J Sareen, J R Walker, S B Patten, A Singer, L M Lix, C A Hitchon, R El-Gabalawy, A Katz, J D Fisk, C N Bernstein
AIMS: After the diagnosis of immune-mediated inflammatory diseases (IMID) such as inflammatory bowel disease (IBD), multiple sclerosis (MS) and rheumatoid arthritis (RA), the incidence of psychiatric comorbidity is increased relative to the general population. We aimed to determine whether the incidence of psychiatric disorders is increased in the 5 years before the diagnosis of IMID as compared with the general population. METHODS: Using population-based administrative health data from the Canadian province of Manitoba, we identified all persons with incident IBD, MS and RA between 1989 and 2012, and cohorts from the general population matched 5 : 1 on year of birth, sex and region to each disease cohort...
November 3, 2017: Epidemiology and Psychiatric Sciences
Akiko Asano, Shohei Numata, Takeshi Yamada, Katsuhiko Minoura, Mitsunobu Doi
Ascidiacyclamide [ASC, cyclo(-Ile-oxazoline-d-Val-thiazole-)2] is a cyclic octapeptide isolated from tunicates. We designed ASC analogues [cyclo(-Ile-Xxx-d-Val-thiazole-)2] in which Pro or a homologue was substituted for oxazoline: [Pro]ASC (Xxx: proline), [Aze]ASC (Xxx: (S)-Azetidine-2-carboxylic acid), [Pip]ASC (Xxx: (S)-Piperidine-2-carboxylic acid) and [ΔPro]ASC (Xxx: (S)-3-pyrroline-2-carboxylic acid) to explore their potential to serve as substitutes for the oxazoline ring. The conformations of these analogues were examined using X-ray diffraction, (1)H NMR and CD spectroscopy...
October 26, 2017: Bioorganic & Medicinal Chemistry
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