Read by QxMD icon Read


Brendan Luke Wilkinson, Robert Ben, Pierre Moens, Toby Bell, Charl Faul, Charles Jarrett-Wilkins, Michael Beards, Madeleine Katrina Adam, Emiliyan Staykov, Liam MacFarlane, Jacqueline Matthews
Antifreeze glycoproteins (AFGPs) are polymeric natural products that have drawn considerable interest in diverse research fields owing to their potent ice recrystallization inhibition (IRI) activity. Self- assembled materials have emerged as a promising class of biomimetic ice growth inhibitor, yet the development of AFGP-based supramolecular materials that emulate the aggregative behavior of AFGPs have not yet been reported. Here, we demonstrate the first example of the 1D self-assembly and IRI activity of AFGP-functionalized perylene bisimides (AFGP-PBIs)...
April 12, 2018: Chemistry: a European Journal
Lijun Liang, Xin Li
Formation of helical chiroptical self-assemblies via noncovalent interaction is a widely observed phenomenon in nature, the mechanism of which remains insufficiently understood. Employing an amphiphilic perylene-sugar dyad molecule (PBI-HAG) as an example, we report that the modulatable supramolecular helicity may emerge from an aggregating process that is dominated by competition between two types of noncovalent interaction: hydrogen bonding and π-π stacking. The interplay between these two driving forces, which is greatly affected by the solvent environment, determines the morphology the supramolecular assembly of PBI-HAGs...
February 12, 2018: Journal of Molecular Modeling
Dave John Adams, Emily Draper, Lewis Archibald, Michael Nolan, Ralf Schweins, Martijn Zwijnenburg, Stephen Sproules
Perylene bisimides (PBIs) self-assemble in solution. The solubility of the PBIs is commonly changed through the choice of substituents at the imide positions. It is generally assumed this substitution does not affect the electronic properties of the PBI, and that the properties of the self-assembled aggregate are essentially that of the isolated molecule. However, substituents do affect the self-assembly, resulting in potentially different packing in the formed aggregates. Here, we show that the photoconductivity of films formed from a library of substituted PBIs varies strongly with the substituent and demonstrate that this is due to the different ways in which they pack...
February 6, 2018: Chemistry: a European Journal
Ravindra Kumar Gupta, Doddamane S Shankar Rao, S Krishna Prasad, Ammathnadu S Achalkumar
Three new heteroatom bay-annulated perylene bisimides (PBIs) have been synthesized by microwave-assisted synthesis in excellent yield. N-annulated and S-annulated perylene bisimides exhibited columnar hexagonal phase, whereas Se-annulated perylene bisimide exhibited low temperature columnar oblique phase in addition to the high temperature columnar hexagonal phase. The cup shaped bay-annulated PBIs pack into columns with enhanced intermolecular interactions. In comparison to PBI, these molecules exhibited lower melting and clearing temperature, with good solubility...
March 7, 2018: Chemistry: a European Journal
Na Liu, Jongyeol Baek, Seung Min Kim, Seongin Hong, Young Ki Hong, Yang Soo Kim, Hyun-Suk Kim, Sunkook Kim, Jozeph Park
In this study, we propose a method for improving the stability of multilayer MoS2 field-effect transistors (FETs) by O2 plasma treatment and Al2 O3 passivation while sustaining the high performance of bulk MoS2 FET. The MoS2 FETs were exposed to O2 plasma for 30 s before Al2 O3 encapsulation to achieve a relatively small hysteresis and high electrical performance. A MoOx layer formed during the plasma treatment was found between MoS2 and the top passivation layer. The MoOx interlayer prevents the generation of excess electron carriers in the channel, owing to Al2 O3 passivation, thereby minimizing the shift in the threshold voltage (Vth ) and increase of the off-current leakage...
December 13, 2017: ACS Applied Materials & Interfaces
S Andrew Garbacz, Kara Hirano, Kent McIntosh, John W Eagle, Devon Minch, Christopher Vatland
The purpose of this study was to identify barriers and facilitators to family engagement in schools implementing schoolwide positive behavioral interventions and supports (PBIS). Participants consisted of 1 representative member each from 204 school PBIS teams across 3 states. Qualitative analysis guided examination of responses to 1 question regarding barriers and 2 questions about facilitators to family engagement. Survey respondents identified key barriers to family engagement as a lack of resources, inconsistent communication, and reluctance of families and school staff to partner...
November 20, 2017: School Psychology Quarterly
Ji-Eun Lee, Ye Ri Han, Sujin Ham, Chul-Ho Jun, Dongho Kim
We have investigated the fundamental photophysical properties of surface-bound perylene bisimide (PBI) molecules in a solution-phase at the single-molecule level. By efficient immobilization of single PBIs on glass, we were able to simultaneously monitor fluorescence intensity trajectories, fluorescence lifetimes, and emission spectra of individual PBIs in organic and aqueous media using confocal microscopy. We showed that the fluorescence dynamics of single PBIs in the solution phase is highly dependent on their local and chemical environments...
November 8, 2017: Physical Chemistry Chemical Physics: PCCP
Wolfgang Wagner, Marius Wehner, Vladimir Stepanenko, Soichiro Ogi, Frank Würthner
The self-assembly of a new perylene bisimide (PBI) organogelator with 1,7-dimethoxy substituents in the bay position affords non-fluorescent H-aggregates at high cooling rates and fluorescent J-aggregates at low cooling rates. Under properly adjusted conditions, the kinetically trapped "off-pathway" H-aggregates are transformed into the thermodynamically favored J-aggregates, a process that can be accelerated by the addition of J-aggregate seeds. Spectroscopic studies revealed a subtle interplay of π-π interactions and intra- and intermolecular hydrogen bonding for monomeric, H-, and J-aggregated PBIs...
December 11, 2017: Angewandte Chemie
Zongxia Guo, Kun Wang, Ping Yu, Xiangnan Wang, Shusha Lan, Kai Sun, Yuanping Yi, Zhibo Li
The effect of the length of linear alkyl chains substituted at imine positions on the assembly of tetrachlorinated perylene bisimides (1: PBI with -C6 H13 ; 2: PBI with -C12 H25 ) has been investigated. Solvent-induced assembly was performed in solutions of THF and methanol with varying volume ratios. Morphological (SEM, AFM, and TEM) and spectral (UV/Vis, fluorescence, FTIR, and XRD) methods were used to characterize the assembled nanostructures and the molecular arrangement in the aggregates. It was found that uniform structures could be obtained for both molecules in solutions with a high ratio of methanol...
November 2, 2017: Chemistry, An Asian Journal
Marko Kete, Olena Pliekhova, Lev Matoh, Urška Lavrenčič Štangar
A compact reactor for photocatalytic oxidation and photocatalytic ozonation water treatment was developed and evaluated by using four model pollutants. Additionally, combinations of pollutants were evaluated. Specially produced Al2O3 porous reticulated monolith foams served as TiO2 carriers, offering a high surface area support. UV lamps were placed in the interior to achieve reduced dimensions of the reactor (12 cm in diameter × 20 cm in height). Despite its small size, the overall photocatalytic cleaning capacity was substantial...
August 15, 2017: Environmental Science and Pollution Research International
Damla Inan, Rajeev K Dubey, Nick Westerveld, Jorrit Bleeker, Wolter F Jager, Ferdinand C Grozema
We report here the synthesis and photophysical study of a series of electron donor-acceptor molecules, in which electron-donating 4-methoxyphenoxy groups are attached to the 1,7-bay positions of four different perylene tetracarboxylic acid derivatives, namely, perylene tetraesters 1, perylene monoimide diesters 2, perylene bisimides 3, and perylene monobenzimidazole monoimides 4. These perylene derivatives are used because of their increasing order of electron-accepting capability upon moving from 1 to 4. Two additional donor-acceptor molecules are synthesized by linking electron-donating 4-methoxyphenyl groups to the imide position of perylene monoimide diester 2 and perylene bisimide 3...
June 22, 2017: Journal of Physical Chemistry. A
Daniel Görl, Bartolome Soberats, Stefanie Herbst, Vladimir Stepanenko, Frank Würthner
The self-assembly of perylene bisimide (PBI) dyes bearing oligo ethylene glycol (OEG) units in water affords responsive functional nanostructures characterized by their lower critical solution temperature (LCST). Tuning of the LCST is realized by a supramolecular approach that relies on two structurally closely related PBI-OEG molecules. The two PBIs socially co-assemble in water and the resulting nanostructures exhibit a single LCST in between the transition temperatures of the aggregates formed by single components...
November 1, 2016: Chemical Science
Mitsuru Kojima, Akira Tamoto, Naoki Aratani, Hiroko Yamada
We have prepared a series of aniline-linked and fused perylene bisimides (PBIs) for making near-infrared (NIR) fluorophores. During this research, we found an unexpected rearrangement reaction on the PBI core for the first time. The aniline- and phenothiazine-fused PBIs exhibit excellent absorption ability and visible-to-NIR emission owing to their intramolecular charge transfer character.
May 23, 2017: Chemical Communications: Chem Comm
John Okombo, Kawaljit Singh, Godfrey Mayoka, Ferdinand Ndubi, Linley Barnard, Peter M Njogu, Mathew Njoroge, Liezl Gibhard, Christel Brunschwig, Mireille Vargas, Jennifer Keiser, Timothy J Egan, Kelly Chibale
The extensive use of praziquantel against schistosomiasis raises concerns about drug resistance. New therapeutic alternatives targeting critical pathways within the parasite are therefore urgently needed. Hemozoin formation in Schistosoma presents one such target. We assessed the in vitro antischistosomal activity of pyrido[1,2-a]benzimidazoles (PBIs) and investigated correlations with their ability to inhibit β-hematin formation. We further evaluated the in vivo efficacy of representative compounds in experimental mice and conducted pharmacokinetic analysis on the most potent...
June 9, 2017: ACS Infectious Diseases
Katharina Huth, Timm Heek, Katharina Achazi, Christian Kühne, Leonhard H Urner, Kevin Pagel, Jens Dernedde, Rainer Haag
A series of water-soluble, hydroxylated and sulphated, polyglycerol (PG) dendronised, monofunctional perylene bisimides (PBIs) were synthesised in three generations. Their photophysical properties were determined by absorption and emission spectroscopy and their suitability as potential biolabels examined by biological in vitro studies after bioconjugation. It could be shown that the photophysical properties of the PBI labels can be improved by increasing the sterical demand and ionic charge of the attached dendron...
April 6, 2017: Chemistry: a European Journal
Robert H Horner, George Sugai, Dean L Fixsen
Implementing evidence-based practices is becoming both a goal and standard across medicine, psychology, and education. Initial successes, however, are now leading to questions about how successful demonstrations may be expanded to scales of social importance. In this paper, we review lessons learned about scaling up evidence-based practices gleaned from our experience implementing school-wide positive behavioral interventions and supports (PBIS) across more than 23,000 schools in the USA. We draw heavily from the work of Flay et al...
March 2017: Clinical Child and Family Psychology Review
Gunsu Kimyon, Taner Turan, Derman Basaran, Osman Turkmen, Alper Karalok, Tolga Tasci, Gokhan Tulunay, Mehmet Faruk Kose
AIM: The aim of this study was to evaluate the treatment options and post-brain involvement survival (PBIS) of patients with isolated brain involvement from endometrial cancer (EC). MATERIALS AND METHODS: The literature electronic search was conducted from 1972 to May 2016 to identify articles about isolated (without extracranial metastases) brain involvement from EC at recurrence and the initial diagnosis. Forty-eight articles were found. After comprehensive evaluation of case series and case reports, the study included 49 cases...
February 2017: International Journal of Gynecological Cancer
Li Zhang, Dezhi He, Yudong Liu, Kun Wang, Zongxia Guo, Jianbin Lin, Hui-Jun Zhang
A series of 2,5,8,11-tetraalkenyl perylene bisimide (PBI) derivatives were synthesized through Ru(II)- or Rh(III)-catalyzed regio- and steroselective oxidative C-H olefination in one step. The optical electronic and self-assembly of the 2,5,8,11-substituted PBIs were investigated, which showed great potential in optoelectronic applications.
November 18, 2016: Organic Letters
Ming-Shou Ho, Benjamin E Partridge, Hao-Jan Sun, Dipankar Sahoo, Pawaret Leowanawat, Mihai Peterca, Robert Graf, Hans W Spiess, Xiangbing Zeng, Goran Ungar, Paul A Heiney, Chain-Shu Hsu, Virgil Percec
Synthesis, structural, and retrostructural analysis of a library containing 16 self-assembling perylene (PBI), 1,6,7,12-tetrachloroperylene (Cl4PBI), naphthalene (NBI), and pyromellitic (PMBI) bisimides functionalized with environmentally friendly AB3 chiral racemic semifluorinated minidendrons at their imide groups via m = 0, 1, 2, and 3 methylene units is reported. These semifluorinated compounds melt at lower temperatures than homologous hydrogenated compounds, permitting screening of all their thermotropic phases via structural analysis to discover thermodynamically controlled helical crystallization from propeller-like, cogwheel, and tilted molecules as well as lamellar-like structures...
December 12, 2016: ACS Combinatorial Science
Dipankar Sahoo, Mihai Peterca, Emad Aqad, Benjamin E Partridge, Paul A Heiney, Robert Graf, Hans W Spiess, Xiangbing Zeng, Virgil Percec
Perylene bisimide derivatives (PBIs) are known to form only columnar or lamellar assemblies. There is no known example of a PBI self-assembling into a supramolecular sphere. Therefore, periodic and quasiperiodic arrays generated from spherical assemblies produced from PBIs are also not known. Here, a PBI functionalized at its imide groups with a second generation self-assembling dendron is reported to self-assemble into supramolecular spheres. These spheres self-organize in a body-centered cubic (BCC) periodic array, rarely encountered for self-assembling dendrons but often encountered in block copolymers...
November 9, 2016: Journal of the American Chemical Society
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"