bluuebunny/crossref_metadata_2025_split huggingface dataset:
Noncharged and Charged Monodendronised Perylene Bisimides as Highly Fluorescent Labels and their Bioconjugates
Authors: Huth Katharina , Heek Timm , Achazi Katharina , Kühne Christian , Urner Leonhard H. , Pagel Kevin , Dernedde Jens , Haag Rainer 
Published: January 2017

AbstractA 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. Thereby, charged labels show superior suppression of aggregation over charge neutral labels owing to electrostatic repulsion forces on the PG‐dendron. The ionic charges also enabled a reduction in dendron generation while retaining the labels’ outstanding fluorescence quantum yields (FQYs) up to 100 %. These core‐unsubstituted perylene derivatives were successfully applied as fluorescent labels upon bioconjugation to the therapeutic antibody cetuximab. The dye‐antibody conjugates showed a strongly enhanced aggregation tendency compared to the corresponding free dyes. Biological evaluation by receptor‐binding, cellular uptake, and cytotoxicity studies revealed that labelling did not affect the antibody's function, which renders the noncharged and charged dendronised PBIs suitable candidates as fluorescent labels in biological imaging.
Excited State N−H Tautomer Selectivity in the Singlet Energy Transfer of a Zinc(II)‐Porphyrin–Truxene–Corrole Assembly
Authors: Langlois Adam , Xu Hai‐Jun , Karsenti Paul‐Ludovic , Gros Claude P. , Harvey Pierre D. 
Published: January 2017

AbstractAn original corrole‐containing polyad for S1 energy transfer, in which one zinc(II)‐porphyrin donor is linked to two free‐base corrole acceptors by a truxene linker, is reported. This polyad exhibits a rapid zinc(II)‐porphyrin*→free‐base corrole transfer (4.83×1010 s−1; 298 K), even faster than the tautomerization in the excited state processes taking advantage of the good electronic communication provided by the truxene bridge. Importantly, the energy transfer process shows approximately 3‐fold selectivity for one corrole N−H tautomer over the other even at low temperature (77 K). This selectivity is due to the difference in the J‐integral being effective in both the Förster and Dexter mechanisms. The data are rationalized by DFT computations.
Synthesis of the Smallest Member of the Silylketene Family: H3SiC(H)=C=O
Authors: Tarczay György , Förstel Marko , Góbi Sándor , Maksyutenko Pavlo , Kaiser Ralf I. 
Published: January 2017

AbstractExploiting photoionization reflectron time‐of‐flight mass spectrometry (PI‐ReTOF‐MS) combined with electronic structure calculations, it is shown that the hitherto elusive silylketene molecule (H3SiC(H)=C=O)—the isovalent counterpart of the well‐known methylketene molecule—is forming via interaction of energetic electrons with low‐temperature silane–carbon monoxide ices. In combination with the infrared spectroscopically detected triplet dicarbon monoxide reactant, electronic structure calculations suggest that dicarbon monoxide reacts with silane via a de facto insertion of the terminal carbon atom into a silicon–hydrogen single bond. This is followed by non‐adiabatic reaction dynamics triggered by the heavy silicon atom intersystem crossing from the triplet to the singlet manifold, eventually leading to the formation of silylketene. The non‐equilibrium nature of the elementary reactions within the exposed ices results in an exciting and novel chemistry which cannot be explored via traditional preparative chemistry. Since the replacement of hydrogen in silane can introduce side groups such as silyl or alkyl, the reaction of triplet dicarbon monoxide with silane represents the parent system for a previously disregarded reaction class revealing an elegant path to access the largely reactive group of silylketenes.
The Impact of the Interplay between Steric and Electronic Effects on the Synthesis and Optical Properties of Diketopyrrolopyrroles Bearing Pyridine Moieties
Authors: Vakuliuk Olena , Purc Anna , Clermont Guillaume , Blanchard‐Desce Mireille , Gryko Daniel T. 
Published: January 2017

AbstractThe influence of a combination of steric and electronic factors on both the preparation and the optical properties of diketopyrrolopyrroles was investigated. The attachment of a cyano group to the electron‐deficient pyridine ring overcame the negative influence of the flanking methyl group on the efficiency of the synthesis of diketopyrrolopyrroles. Diketopyrrolopyrroles possessing pyridine‐N‐oxide moieties were studied for the first time. We have also shown that reactions of cyanopyridines possessing an additional dialkylamino group were very capricious and depending on the relative position of all substituents, can lead to low yields of diketopyrrolopyrroles. The interplay between the dihedral angle between the diketopyrrolopyrrole core and the pyridyl substituents as well as the presence and position of electron‐donating moieties made it possible to modulate the photophysical properties ofN,N′‐dialkyldiketopyrrolopyrroles. In particular, it was found that pyridine‐N‐oxides as the aryl moieties had a strong influence on the optical properties of diketopyrrolopyrroles, shifting both absorption and emission bands bathochromically. Two‐photon absorption cross‐sections had low values except for those dyes possessing a clear quadrupolar centrosymmetric nature.
Blue‐Light‐Emitting Triazolopyridinium and Triazoloquinolinium Salts
Authors: Carboni Valentina , Su Xin , Qian Hai , Aprahamian Ivan , Credi Alberto 
Published: January 2017

AbstractCompounds that emit blue light are of interest for applications that include optoelectronic devices and chemo/biosensing and imaging. The design and synthesis of small organic molecules that can act as high‐efficiency deep‐blue‐light emitters in the solid state and can be easily processed from solutions represents a significant challenge. Herein we present the preparation and photophysical, photochemical and electrochemical properties of a series of triazolopyridinium and triazoloquinolinium compounds. The compounds are soluble in water or polar organic solvents and exhibit photoluminescence in the blue region of the spectrum in fluid solution, in the solid state and in a frozen matrix.
Sexual selection constrains the body mass of male but not female mice
Authors: Ruff James S. , Cornwall Douglas H. , Morrison Linda C. , Cauceglia Joseph W. , Nelson Adam C. , Gaukler Shannon M. , Meagher Shawn , Carroll Lara S. , Potts Wayne K. 
Published: January 2017

AbstractSexual size dimorphism results when female and male body size is influenced differently by natural and sexual selection. Typically, in polygynous species larger male body size is thought to be favored in competition for mates and constraints on maximal body size are due to countervailing natural selection on either sex; however, it has been postulated that sexual selection itself may result in stabilizing selection at an optimal mass. Here we test this hypothesis by retrospectively assessing the influence of body mass, one metric of body size, on the fitness of 113 wild‐derived house mice (Mus musculus) residing within ten replicate semi‐natural enclosures from previous studies conducted by our laboratory. Enclosures possess similar levels of sexual selection, but relaxed natural selection, relative to natural systems. Heavier females produced more offspring, while males of intermediate mass had the highest fitness. Female results suggest that some aspect of natural selection, absent from enclosures, acts to decrease their body mass, while the upper and lower boundaries of male mass are constrained by sexual selection.
Tri‐trophic ecology of native parasitic nest flies of birds inTobago
Authors: Knutie Sarah A. , Herman Jordan M. , Owen Jeb P. , Clayton Dale H. 
Published: January 2017

AbstractIntroduced parasites threaten host populations around the world. For example, introduced parasitic nest flies (Philornis downsi) have contributed to the decline of several species of Darwin's finches in the Galápagos Islands. Introduced parasites are thought to have severe effects on native hosts because the hosts do not have effective defenses against such parasites and/or because introduced parasites have escaped the native enemies that keep their own populations in check. Studying effects of parasites on native hosts is an essential step in testing these causal hypotheses. We conducted a field experiment to assess the virulence of a native species ofPhilornis(Philornis trinitensis), which parasitizes birds on the island of Tobago. We manipulated flies in nests of black‐faced grassquits (Tiaris bicolor), a close relative of Darwin's finches, as well as tropical mockingbirds (Mimus gilvus), a congener of the Galápagos mockingbird (Mimus parvulus). We predicted thatP. trinitensiswould be relatively avirulent because its native hosts in Tobago have had time to evolve effective defenses against it. We also noted the presence of parasitoids and other enemies ofPhilornisin Tobago nests. Surprisingly, effects of nativeP. trinitensison Tobago birds were similar to the effects of introducedP. downsion birds in the Galápagos. Flies reduced the reproductive success of grassquits, but not mockingbirds, which are also relatively unaffected byPhilornisin the Galapagos. Thus, nativePhilornisflies are not less virulent than introduced flies. The prevalence ofPhilornisin Tobago was lower than the prevalence ofPhilornisin the Galápagos. Presumed enemies ofPhilornis(parasitoid wasps and ants) were relatively common in nests of birds in Tobago, but largely absent from nests in the Galápagos. We suggest that introducedP. downsiin the Galápagos is widespread, not because hosts lack defenses, but because it has left its enemies behind.
Circumpolar analysis of the Adélie Penguin reveals the importance of environmental variability in phenological mismatch
Authors: Youngflesh Casey , Jenouvrier Stephanie , Li Yun , Ji Rubao , Ainley David G. , Ballard Grant , Barbraud Christophe , Delord Karine , Dugger Katie M. , Emmerson Louise M. , Fraser William R. , Hinke Jefferson T. , Lyver Phil O’B. , Olmastroni Silvia , Southwell Colin J. , Trivelpiece Susan G. , Trivelpiece Wayne Z. , Lynch Heather J. 
Published: January 2017

AbstractEvidence of climate‐change‐driven shifts in plant and animal phenology have raised concerns that certain trophic interactions may be increasingly mismatched in time, resulting in declines in reproductive success. Given the constraints imposed by extreme seasonality at high latitudes and the rapid shifts in phenology seen in the Arctic, we would also expect Antarctic species to be highly vulnerable to climate‐change‐driven phenological mismatches with their environment. However, few studies have assessed the impacts of phenological change in Antarctica. Using the largest database of phytoplankton phenology, sea‐ice phenology, and Adélie Penguin breeding phenology and breeding success assembled to date, we find that, while a temporal match between Penguin breeding phenology and optimal environmental conditions sets an upper limit on breeding success, only a weak relationship to the mean exists. Despite previous work suggesting that divergent trends in Adélie Penguin breeding phenology are apparent across the Antarctic continent, we find no such trends. Furthermore, we find no trend in the magnitude of phenological mismatch, suggesting that mismatch is driven by interannual variability in environmental conditions rather than climate‐change‐driven trends, as observed in other systems. We propose several criteria necessary for a species to experience a strong climate‐change‐driven phenological mismatch, of which several may be violated by this system.
Antifouling biocides in German marinas: Exposure assessment and calculation of national consumption and emission
Authors: Daehne Dagmar , Fürle Constanze , Thomsen Anja , Watermann Burkard , Feibicke Michael 
Published: January 2017

Abstract

The authorization of biocidal antifouling products for leisure boats is the subject of the European Union Biocides Regulation 528/2012. National specifics may be regarded by the member states in their assessment of environmental risks. The aim of this survey was to collect corresponding data and to create a database for the environmental risk assessment of antifouling active substances in German surface waters. Water concentrations of current antifouling active substances and selected breakdown products were measured in a single-sampling campaign covering 50 marinas at inland and coastal areas. Increased levels were found for Zn, Cu, and cybutryne. For the latter, the maximum allowable concentration according to Directive 2013/39/EU was exceeded at 5 marinas. For Cu, local environmental quality standards were exceeded at 10 marinas. Base data on the total boat inventory in Germany were lacking until now. For that reason, a nationwide survey of mooring berths was conducted by use of aerial photos. About 206 000 mooring berths obviously used by boats with a potential antifouling application were counted. The blind spot of very small marinas was estimated at 20 000 berths. Seventy-one percent of berths were located at freshwater sites, illustrating the importance of navigable inland waterways for leisure boat activities and underlining the need for a customized exposure assessment in these areas. Moreover, the national consumption of all antifouling products for leisure boats was calculated. The total amount of 794 tonnes/annum (t/a) consisted of 179 t/a of inorganic Cu compounds, 19 t/a of organic cobiocides, and 49.5 t/a of Zn. With regard to weight proportion, 141 t/a Cu and 40 t/a Zn were consumed. Assuming an emission ratio of 50% during service life, 70.5 t/a of Cu amounted to 15% of all external sources for Cu release to German surface waters. These figures highlight the need for mitigation measures. Integr Environ Assess Manag 2017;13:892–905. © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC)

Key Points
Seventy-one percent of the total berths used by leisure boats are situated at German freshwater sites. A survey on antifouling biocides in 50 marinas revealed the actual load situation. Cuprous compounds reached approximately 90% of consumed antifouling agents. Inputs of Cu emissions by leisure boats amount to 15% of all external sources of Cu released to German surface waters.
Little things that count: A call for organizational research on microbusinesses
Authors: Brawley Alice M. , Pury Cynthia L.S. 
Published: January 2017

SummaryThe purpose of this Incubator is to encourage organizational researchers to attend to the most common type of business in the United States—the microbusiness. After defining and describing these businesses, we propose research questions on defining and managing performance, organizational citizenship, and work–family conflict in this novel business setting. Copyright © 2017 John Wiley & Sons, Ltd.
Obesity and radiological severity are associated with viscosupplementation failure in patients with knee osteoarthritis
Authors: Eymard Florent , Chevalier Xavier , Conrozier Thierry 
Published: January 2017

ABSTRACTViscosupplementation (VS) is still controversial. One of the key points is the lack of well‐identified factors of response. We aimed to identify clinical and radiological factors associated with lack of relevant response after intra‐articular (IA) hyaluronic acid (HA) injections in symptomatic knee osteoarthritis patients. A post hoc analysis of the HAV‐2012 trial, a controlled, multicentre, double‐blind, randomized, non‐inferiority trial comparing 3 weekly IA injections of HA (HAnox‐M or BioHA) for symptomatic tibiofemoral OA was performed. At inclusion, demographic, anthropometric, clinical data (WOMAC score, patient global assessment, presence of knee effusion), and radiological data (OARSI grade, patello‐femoral involvement) were recorded. VS response was defined according to OMERACT–OARSI response criteria at month 6. Predictors of response were investigated in univariate then in multivariate analysis. One hundred and sixty‐six patients with full available data were included. As baseline characteristics and treatment effectiveness were similar between the 2 HA groups, their data were pooled. The mean age was 65.2 [63.7–66.8] years; 101 (60.8%) were women; 73 (44.0%) had severe TF space narrowing. At 6 months, 113 patients (68.1%) were responders. Multivariate analysis showed that obesity (BMI ≥30 kg/m2) and radiological severity (OARSI grade 3) were significantly associated with VS failure (p = 0.001 and p = 0.008, respectively). Moreover, the association of obesity and severe TF space narrowing significantly increased the risk of VS failure. Baseline pain intensity and functional impairment were not associated with VS response. Consequently, IA injection of HA for knee OA should mainly be considered in subjects with low BMI and mild TF space narrowing. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2269–2274, 2017.
Transcriptional and posttranscriptional regulation of Shigella shuT in response to host‐associated iron availability and temperature
Authors: Wei Yahan , Kouse Andrew B. , Murphy Erin R. 
Published: January 2017

AbstractLike most bacteria, Shigella must maintain a precise balance between the necessity and toxicity of iron; a balance that is achieved, at least in part, by regulating the production of bacterial iron acquisition systems in response to specific environmental signals. Using the Shigella heme utilization (Shu) system, S. dysenteriae is able to acquire iron from heme, a potentially rich source of nutritional iron within the otherwise iron‐limited environment of the human host. Investigations presented within reveal two distinct molecular mechanisms underlying previously uncharacterized transcriptional and translational regulation of shuT, a gene encoding the periplasmic‐binding component of the Shu system. While shuT transcription is regulated in response to iron availability via a process dependent upon the global regulator Fur and a Fur‐binding site located immediately downstream of the promoter, shuT translation is regulated in response to environmental temperature via the activity of an RNA thermometer located within the 5′ untranslated region of the gene. Such complex regulation likely increases the fitness of S. dysenteriae by ensuring maximal ShuT production when the pathogen is within the iron‐limited and relatively warm environment of the infected host, the only environment in which heme will be encountered as a potential source of essential iron.
MTCH2 is a conserved regulator of lipid homeostasis
Authors: Rottiers Veerle , Francisco Adam , Platov Michael , Zaltsman Yehudit , Ruggiero Antonella , Lee Siu Sylvia , Gross Atan , Libert Sergiy 
Published: January 2017

ObjectiveMore than one‐third of U.S. adults have obesity, causing an alarming increase in obesity‐related comorbidities such as type 2 diabetes. The functional role of mitochondrial carrier homolog 2 (MTCH2), a human obesity‐associated gene, in lipid homeostasis was investigated in Caenorhabditis elegans, cell culture, and mice.MethodsIn C. elegans, MTCH2/MTCH‐1 was depleted, using RNAi and a genetic mutant, and overexpressed to assess its effect on lipid accumulation. In cells and mice, shRNAs against MTCH2 were used for knockdown and MTCH2 overexpression vectors were used for overexpression to study the role of this gene in fat accumulation.ResultsMTCH2 knockdown reduced lipid accumulation in adipocyte‐like cells in vitro and in C. elegans and mice in vivo. MTCH2 overexpression increased fat accumulation in cell culture, C. elegans, and mice. Acute MTCH2 inhibition reduced fat accumulation in animals subjected to a high‐fat diet. Finally, MTCH2 influenced estrogen receptor 1 (ESR1) activity.ConclusionsMTCH2 is a conserved regulator of lipid homeostasis. MTCH2 was found to be both required and sufficient for lipid homeostasis shifts, suggesting that pharmacological inhibition of MTCH2 could be therapeutic for treatment of obesity and related disorders. MTCH2 could influence lipid homeostasis through inhibition of ESR1 activity.
Selective water‐permeable channels induced by polystyrene brushes within hairy nanocellulose/cellulose acetate membrane
Authors: Lessan F. , Karimi M. 
Published: January 2017

Hairy nanocellulose (NC) was prepared by in‐situ admicellar polymerization of styrene on NC surface in the presence of cetyltrimethylammonium bromide through a stepwise fashion. It was also tried to achieve three hairy NCs with different polystyrene (PS) brush contents (i.e. 40, 50, and 80%) through altering monomer initial concentration. Then, NC and three hairy NCs were separately added into cellulose acetate (CA) solutions to fabricate membranes via the phase inversion technique. Transmission electron microscope images show that NC and three hairy NCs are spherical‐shaped nanoparticles. Results of Fourier transform infrared spectra provide clear evidence of PS brush being attached to the NC surfaces. Thermal gravimetric analysis confirms that increasing styrene initial concentration leads to enhanced PS content of hairy NCs. Results also elucidate that dispersions of prepared hairy NCs are highly stable even at high loading levels. It was found that incorporation of 1 wt% hairy NC with optimum brush content of 50% within CA membranes results in the increasing membrane water permeability from 7 to 40 l/m2 hr with no change in its selectivity. Indeed, new interactions induced by PS brushes at hairy NC/CA interfaces result in the creation of connected channels at the interfaces which facilitate water transport through the membrane. This study provides insights into the key role that PS brushes play in overcoming the dispersion problems of NC in nonpolar media and offers guidelines to tailor channels within hairy NC/CA membrane for enhanced filtration performance. Copyright © 2017 John Wiley & Sons, Ltd.
4H‐cyclopenta[2,1‐b:3,4‐b′]dithiophen‐4‐one (CPDTO) homopolymer with side chains on every other CPDTO
Authors: Sun Jianyuan , Venkatesan Swaminathan , Dubey Ashish , Qiao Qiquan , Zhang Cheng 
Published: January 2017

ABSTRACTA soluble 4H‐cyclopenta[2,1‐b;3,4‐b′]dithiophene‐4‐one (CPDTO)‐based polymer (C6‐PCPDTO) has been synthesized from two monomers derived from nonalkylated CPDTO and didodecyl CPDTO (C12‐CPDTO). Proton NMR, thermal analysis, UV–vis absorption, cyclic voltammetry, and XRD are used to characterize the polymer in solution and film. The new polymer has an optical bandgap of 1.28 eV in film, and has strong interchain interaction in chloroform solutions. The polymer contains a significant amount of homocoupled segments. The regular segments and homocoupled CPDTO segments render the polymer highly aggregating in solution. The non‐planar homocoupled C12‐CPDTO segments prevent the polymer from forming regular π‐stacks, resulting in a low SCLC hole mobility (3.88 × 10−7 cm2V−1s−1). CV experiments show that C6‐PCPDTO is stable in its oxidized and reduced states. Solar cell devices were fabricated from C6‐PCPDTO2:PC60BM blends of different weight ratios. High PC60BM loading (80% or greater) was required for the devices to show measurable efficiency, indicating that the limited π‐stacking of the polymer is not sufficient to cause effective phase separation. Further development of synthetic method is still needed to eliminate structural defects so that long‐range ordered pi‐stacking can be realized in the polymer for these applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1077–1085