bluuebunny/crossref_metadata_2025_split huggingface dataset:
Well‐defined polymers containing high density of pendant viologen groups
Authors: Wang Zhaoxu , Tsarevsky Nicolay V. 
Published: February 2017

ABSTRACTAtom transfer radical polymerization (ATRP) of a viologen‐containing methacrylate, 1‐propyl‐1′‐[2‐(methacryloyloxy)ethyl]‐4,4′‐bipyridinium dihexafluorophosphate, is reported. To achieve good polymerization control, it was essential to use the viologen‐based monomer with a hexafluorophosphate instead of halide counterion, and 2,2′‐bipyridine as the ligand for the Cu‐based ATRP catalyst. The solubility of produced cationic polymers could be tuned by anion metathesis: the polymers with hexafluorophosphate counterions were soluble in organic solvents (e.g., acetone, DMF), and those with chloride counterions were water‐soluble. In aqueous solutions, the polymers (chloride salts) formed large aggregates, the sizes of which ranged from about 200 to about 400 nm (based on dynamic light scattering measurements) depending on the molecular weight. Upon addition of electrolytes (e.g., NaCl), the aggregates underwent dissociation. The apparent diffusion coefficients of the aggregates existing in aqueous solutions and the products of their electrolyte‐induced dissociation were measured by diffusion‐ordered NMR spectroscopy. The association–dissociation processes were also studied by fluorescence spectroscopy: the aqueous polymer solutions, which were originally fluorescent (λem = 402 nm at λex = 350 nm), lost their fluorescence in the presence of NaCl. The addition of small amounts of the viologen‐containing polyelectrolytes to solutions of inorganic salts (NaCl) altered the crystal morphology of the salts due to interaction of the multiple charged pendant groups with small ions. In the presence of reducing agents, the pendant viologen groups were converted to viologen radical‐cations, which are prone to dimerize reversibly in aqueous solutions. Indeed, marked dimerization of viologen radical cations (with absorbance maxima at 520 and 870 nm) was observed in relatively dilute aqueous solutions (4 mg mL−1) upon addition of reducing agents (hydrazine). © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 55, 1173–1182
Using cluster analysis of anxiety‐depression to identify subgroups of prostate cancer patients for targeted treatment planning
Authors: Sharpley Christopher F. , Bitsika Vicki , Warren Amelia K. , Christie David R.H. 
Published: February 2017

AbstractBackgroundTo explore any possible subgroupings of prostate cancer (PCa) patients based upon their combined anxiety‐depression symptoms for the purposes of informing targeted treatments.MethodsA sample of 119 PCa patients completed the GAD7 (anxiety) and PHQ9 (depression), plus a background questionnaire, by mail survey. Data on the GAD7 and PHQ9 were used in a cluster analysis procedure to identify and define any cohesive subgroupings of patients within the sample.ResultsThree distinct clusters of patients were identified and were found to be significantly different in the severity of their GAD7 and PHQ9 responses, and also by the profile of symptoms that they exhibited.ConclusionsThe presence of these 3 clusters of PCa patients indicates that there is a need to extend assessment of anxiety and depression in these men beyond simple total score results. By applying the clustering profiles to samples of PCa patients, more focussed treatment might be provided to them, hopefully improving outcome efficacy.
Stereo‐Electronic, Molecular Connectivity, and Geometric Configuration Approaches towards Designing Antibacterial Agents from 1, 3, 4‐Thiadiazole as the Starting Molecular Template
Authors: Yusuf Mohammad , Khan Riaz A. , Khan Maria , Ahmed Bahar 
Published: February 2017

AbstractNew 5‐amino‐1,3,4‐thiadiazole‐2‐thiol derivatives have been synthesized based on molecular target designs derived from various molecular descriptors involving configurational geometry, molecular size, and stereoelectronic effects of the desired sub‐structural templates using molecular connectivity design approach. The approach generated fragment‐based pharmacophore sub‐units in comparison to fluoroquinolone template to yield comparable leads with medium molecular size, and nearly flat‐plane molecular geometry framework. The product, namely, 5‐{[‐1‐(4‐chlorophenyl)‐5‐phenyl penta‐2,4‐dien‐1‐ylidene] amino}‐1,3,4‐thiadiazole‐2‐thiol (2 f) showed potent antibacterial activity against both gram‐positive and, gram‐negative strains to validate the design.
Atomically Precise Noble Metal Clusters Harvest Visible Light to Produce Energy
Authors: Jeseentharani V. , Pugazhenthiran N. , Mathew Ammu , Chakraborty Indranath , Baksi Ananya , Ghosh Jyotirmoy , Jash Madhuri , Anjusree G. S. , Deepak T. G. , Nair A. Sreekumaran , Pradeep T. 
Published: February 2017

AbstractAtomically precise gold and silver clusters are a new class of sensitizers which can be used as substitutes for dyes in the classical dye‐sensitized solar cells (DSCs). Here noble metal clusters protected by proteins and thiols (Au30@BSA, Au25SBB18, and Ag44MBA30) have been used for photovoltaic studies. These metal clusters were used as sensitizers for the photoanodes fabricated using TiO2 nanotubes (NTs) and the commercial P25 TiO2 nanoparticles. The TiO2, clusters and the solar cells were characterized by spectroscopy, microscopy, current‐voltage (I‐V) and incident photon‐to‐current conversion efficiency (IPCE) measurements. A systematic I‐V study revealed a conversion efficiency of 0.35 % for the Au30@BSA sensitized solar cell made from TiO2 NTs which showed an IPCE maximum of 3 % at ∼ 400 nm.
AIE Nanodots Obtained from a Pyrene Schiff Base and Their Applications
Authors: Srinivasan Venkatesan , Jhonsi Mariadoss Asha , Dhenadhayalan Namasivayam , Lin King‐Chuen , Jaccob Madhavan , Kathiravan Arunkumar 
Published: February 2017

AbstractDeveloping the aggregation indcued emission (AIE) nanodots as alternates to the conventional inorganic quantum dots is a contemporary research interest towards assorted applications. Herein, we have designed and synthesized a tripodal structured pyrene Schiff base (PS) and it is characterized by 1H NMR, 13C NMR and ESI‐MS techniques. The developed PS exhibit an excellent AIE property in THF:water (10:90) ratio. The formed PS aggregates were meticulously characterized by HR‐SEM, HR‐TEM and AFM measurements. The results reveal that the PS aggregates are spherical in shape with an average diameter of ∼ 1 nm. Hence, the PS aggregates are expressed as AIE nanodots. Intriguingly, the AIE nanodots has high fluorescence lifetime (4 ns) and quantum yield of 54 %, which are adequate to compete with the commercial fluorophores. In addition, molecular structure dependent nano shapes have also been investigated. The PS based AIE nanodots were successfully utilized as a fluorescent probe for several applications such as in‐vitro bioimaging, detection of picric acid and photoinduced electron transfer studies. The confocal fluorescence images of nanodots in HeLa and HEK live cells exhibit higher fluorescence signal which clearly reveal that AIE nanodots can be used as a promising probe for in‐vitro bio‐imaging application. Moreover, the AIE nanodots are employed to detect the picric acid through fluorescence quenching method. Towards the commercial application, the low‐cost fluorescent test strips have also been developed for the detection of picric acid. We have also investigated the electron transfer nature of AIE nanodots with benzyl viologen towards the energy related applications.
A Case of Folding Pattern in Flexible Tripodal of N‐Substituted Bisethylenamine Bridged Pyridazinone Dimers
Authors: Kumar Ranjeet , Gaurav Archana , Pal Shiv , Tewari Ashish Kumar 
Published: February 2017

AbstractPresent manuscript reports three tripodal molecules for their special structural and conformational properties. Interestingly, X‐ray structure revealed that all these molecules adopt folded conformation in solid state. Further, these molecules are flexible due to linker, may exist in various conformations, the studies have been carried out with different conformers through theoretical calculation in gaseous state.
Olive Biophenols as New Antioxidant Additives in Food and Beverage
Authors: Ciriminna Rosaria , Meneguzzo Francesco , Delisi Riccardo , Pagliaro Mario 
Published: February 2017

AbstractReplacing synthetic phenols, sulfites and other synthetic antioxidants and antimicrobials, olive biophenols can be successfully used as multipurpose additives in foodstuffs and beverages. Are these natural phenolics suitable for large‐scale replacement of synthetic additives? This study aims to provide an answer to this and related questions of significant health and environmental significance.
Silver Nanoparticles Modified Graphitic Carbon Nitride Nanosheets as a Significant Bifunctional Material for Practical Applications
Authors: Veerakumar Pitchaimani , Dhenadhayalan Namasivayam , Lin King‐Chuen , Liu Shang‐Bin 
Published: February 2017

AbstractAmine‐functionalized graphitic carbon nitride (NH2/GCN) nanosheets photoluminescence, catalytic properties and excellent water dispersion stability were prepared and characterized by a variety of different analytical and spectroscopic techniques. The well‐dispersed NH2/GCN nanosheets were found to exhibit remarkable pH sensing sensitivity at an ambient temperature with desirable broad detection range (1 ≤ pH ≤ 12). Moreover, upon incorporating silver nanoparticles (Ag NPs), the Ag‐NH2/GCN nanocomposites showed excellent performances for catalytic reduction of 4‐nitrophenol (4‐NP) in NaBH4 with a superior rate constant (k) of 0.1594 s‐1 within as short as 30 s. The NH2/GCN and Ag‐NH2/GCN nanocomposites reported herein therefore render prospective applications as sensitive pH and practical catalytic applications.
Facile Transformation of Nitriles into Thioamides: Application to C‐Glycosyl Nitrile Derivatives
Authors: Ghosh Tamashree , Si Anshupriya , Kumar Misra Anup 
Published: February 2017

AbstractAn effective reaction condition for the rapid transformation of nitrile derivatives into thioamide derivatives has been developed by the treatment with a combination of carbon disulfide and sodium sulfide. The reaction condition is equally effective for the transformation of alkyl, aryl nitriles. C‐Glycosyl nitriles also furnished C‐glycosyl thioamide derivatives in satisfactory yield under the reported reaction condition. The reaction condition is simple, high yielding and suitable for scaled up.
Microwave‐Assisted Ligand‐Free Nickel‐Catalyzed β‐Boration of α,β‐Unsaturated Carbonyl Compounds with Bis(pinacolato)diboron
Authors: Huang Xi , Wang Mingming , Wu Mengying , Wang Jiayi , Peng Yanqing , Song Gonghua 
Published: February 2017

AbstractA simple and efficient ligand‐free nickel‐based catalytic system has been developed for the β‐boration of α,β‐unsaturated carbonyl compounds with bis(pinacolato)diboron. With catalyst loading of 10–15 mol%, a series of β‐boration products from chalcones and cinnamates was obtained rapidly in moderate to excellent yields within 3–30 minutes under a nitrogen atmosphere and microwave irradiation. The combination of hydroboration with microwave irradiation provided a convenient and rapid method to afford a boronate group at the β‐position of carbonyl.
Nanoescapology: progress toward understanding the endosomal escape of polymeric nanoparticles
Authors: Selby Laura I. , Cortez‐Jugo Christina M. , Such Georgina K. , Johnston Angus P.R. 
Published: February 2017

Using nanoparticles to deliver drugs to cells has the potential to revolutionize the treatment of many diseases, including HIV, cancer, and diabetes. One of the major challenges facing this field is controlling where the drug is trafficked once the nanoparticle is taken up into the cell. In particular, if drugs remain localized in an endosomal or lysosomal compartment, the therapeutic can be rendered completely ineffective. To ensure the design of more effective delivery systems we must first develop a better understanding of how nanoparticles and their cargo are trafficked inside cells. This needs to be combined with an understanding of what characteristics are required for nanoparticles to achieve endosomal escape, along with methods to detect endosomal escape effectively. This review is focused into three sections: first, an introduction to the mechanisms governing internalization and trafficking in cells, second, a discussion of methods to detect endosomal escape, and finally, recent advances in controlling endosomal escape from polymer‐ and lipid‐based nanoparticles, with a focus on engineering materials to promote endosomal escape. WIREs Nanomed Nanobiotechnol 2017, 9:e1452. doi: 10.1002/wnan.1452This article is categorized under:

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
One‐Step Concentration of Highly Unsaturated Fatty Acids from Tuna Oil by Low‐Temperature Crystallization
Authors: Zhang Yu , Wang Xiaosan , Xie Dan , Li Yongru , Wang Xingguo 
Published: February 2017

AbstractHighly unsaturated fatty acids (HUFA), including eicosapentaenoic acid (EPA, 20:5n‐3), docosapentaenoic acid (DPA, 22:5n‐3 and 22:5n‐6) and docosahexaenoic acid (DHA, 22:6n‐3), play an important role in human health and nutrition. In this study, concentration of HUFA in free fatty acids (FFA) form by low‐temperature crystallization was investigated. For this purpose, tuna oil (7.1% EPA, 26.8% DHA) was first converted into corresponding FFA. Subsequently, crystallization conditions of various solvent types, the ratio of FFA to acetonitrile, operation temperature and crystallization time were optimized at a small scale of 2 g tuna oil fatty acids. Taking purity and yield into account, the optimum conditions were a 1:10 ratio of FFA to acetonitrile (w/v), −60 °C, and 1 h. The optimal conditions resulted in concentrations of EPA, DHA and HUFA of 15.1, 58.4 and 79.6%, respectively, with corresponding yields of 61.5, 61.8 and 60.7%, respectively. Crystallization was carried out under the optimal conditions at a large scale of 200 g tuna oil FFA, and a similar concentration result was achieved. After evaporating away the solvent, the residual amount of acetonitrile met the US Pharmacopoeia requirement of <410 ppm. The process for enrichment of HUFA is readily scalable, effective and time‐saving.
A prenatal nicotine exposure mouse model of methylphenidate responsive ADHD‐associated cognitive phenotypes
Authors: Zhu Jinmin , Fan Fangfang , McCarthy Deirdre M. , Zhang Lin , Cannon Elisa N. , Spencer Thomas J. , Biederman Joseph , Bhide Pradeep G. 
Published: February 2017

AbstractPrenatal exposure to nicotine via cigarette smoke or other forms of tobacco use is a significant environmental risk factor for attention deficit hyperactivity disorder (ADHD). The neurobiological mechanisms underlying the link between prenatal nicotine exposure (PNE) and ADHD are not well understood. Animal models, especially rodent models, are beginning to bridge this gap in knowledge. Although ADHD is characterized by hyperactivity, inattention, impulsivity and working memory deficits, the majority of the animal models are based on only one or two ADHD associated phenotypes, in particular, hyperactivity or inattention. We report a PNE mouse model that displays the full range of ADHD associated behavioral phenotypes including working memory deficit, attention deficit and impulsive‐like behavior. All of the ADHD‐associated phenotypes respond to a single administration of a therapeutic equivalent dose of methylphenidate. In an earlier study, we showed that PNE produces hyperactivity, frontal cortical hypodopaminergic state and thinning of the cingulate cortex. Collectively, these data suggest that the PNE mouse model recapitulates key features of ADHD and may be a suitable preclinical model for ADHD research.
Parametric investigation on an industrial electromagnetic continuous casting mould performance
Authors: Zhang Lintao , Deng Anyuan , Cameron Ian , Wang Engang , Sienz Johann 
Published: February 2017

Abstract
This research aimed at conducting a quantitative investigation of process parameters on the magnetic field contribution in an electromagnetic continuous casting mould. The Taguchi method (4 factors and 3 factor value levels: L9 orthogonal array) was adopted to design matrix of the simulation runs and the analysis of variance was used to evaluate the contributions of each control factor. The simulations were conducted based on the finite element method and the numerical set-up was validated by the designed experiment. The results showed that the applied alternating current magnitude contributed most (76.64%) to the magnetic field level in the mould, compared to the other control factors. It was followed by the slit length (17.72%), the alternating current frequency (4.17%) and the slit width (1.57%).
Highlights Numerical system was validated by the designed experiment. A quantitative investigation of process parameter on the magnetic field in contribution an EMCC mould was conducted. The current value was the most influential factor, followed by the slit length, current frequency and the slit width.
Stabilization of second order evolution equations by unbounded nonlinear feedback
Authors: Conrad Francis , Pierre Michel 
Published: February 2017

For an abstract evolution equation of the form

u_{tt} + Au + ∂ψ(u_t) \ni 0

, general conditions on the “unbounded” feedback are given, that ensure strong asymptotic stability. Essentially the directions determined by the convex of the minima of the functional

ψ

should not intersect the eigenspaces of

A

. Equivalently, the feedback on the velocity must dissipate enough energy, in the sense that the kernel of the form

\langle ∂ψ(·), ·\rangle

is not larger than the kernel of a “strategic” observation operator, for the uncontrolled system. The particular case where the control operator is the dual of the observation operator is specifically considered: the condition then corresponds to more classical rank conditions on the observation operator. The interest of the present framework is that it applies to boundary controls and to interior controls on thin sets (of zero measure but positive capacity). Several examples, including wave, beam and plate equations are considered.

Résumé

Pour un problème d’évolution abstrait de la forme

u_{tt} + Au + ∂ψ(u_t) \ni 0

, on donne des conditions générales sur le feedback « non borné » pour assurer la stabilité asymptotique forte. Essentiellement les directions déterminées par le convexe des minima de

ψ

ne doivent pas être des directions propres de l’opérateur

A

. De façon équivalente, il faut que le bouclage sur la vitesse soit suffisamment dissipatif, en ce sens que le noyau de la forme

\langle ∂ψ(·), ·\rangle

ne doit pas être plus gros que le noyau d’un observateur « stratégique », pour le système non contrôlé. Le cas particulier où l’opérateur de contrôle est l’adjoint de l’opérateur d’observation est étudié; la condition se ramène alors à des conditions plus classiques de rang sur l’opérateur d’observation. Le cadre proposé ici englobe le cas de contrôles frontières ou intérieurs, distribués ou ponctuels, ainsi que des contrôles unilatéraux. Divers exemples concernant les équations des ondes, des poutres ou des plaques, éventuellement avec des contrôles sur des ensembles « fins », sont proposés.
The existence of Ginzburg–Landau solutions on the plane by a direct variational method
Authors: Yang Yisong 
Published: February 2017

This paper studies the existence and the minimization problem of the solutions of the Ginzburg-Landau equations in

\mathbf R^2

coupled with an external magnetic field or a source current. The lack of a suitable Sobolev inequality makes it necessary to consider a variational problem over a special admissible space so that the space norms of the gauge vector fields of a minimization sequence can be controlled by the corresponding energy upper bound and a solution may be obtained as a minimizer of a modified energy of the problem. Asymptotic properties and flux quantization are established for finite-energy solutions. Besides, it is shown that the solutions obtained also minimize the original Ginzburg–Landau energy when the admissible space is properly chosen.

Résumé

Le but de ce travail est d’étudier l’existence et le problème de minimisation des solutions des équations de Ginzburg-Landau dans

\mathbf R^2

, couplées avec un champ magnétique externe ou une source de courant. L’absence d’une inégalité convenable de Sobolev amène à considérer un problème variationnel sur un espace admissible spécial. Sur cet espace, les normes des champs de vecteurs de la gauge d’une suite minimisante peuvent être contrôlées par la borne supérieure de l’énergie correspondante. Aussi, une solution peut être obtenue comme un minimiseur d’une énergie modifiée du problème. Des propriétés asymptotiques et une quantification de flux sont établies par des solutions d’énergie finie. Entre autres, il est prouvé que les solutions obtenues minimisent aussi l’énergie originale de Ginzburg–Landau lorsque l’espace admissible est convenablement choisi.
A characterization of families of function sets described by constraints on the gradient
Authors: Esposito Antonio Corbo , De Arcangelis Riccardo 
Published: February 2017

One of the results proved in the paper deals with a characterization of the families

\{K (Ω) : Ω \text{ bounded open set}\}

of subsets of

W_{\mathrm{loc}}^{1,\:p}\:(ℝ^{n})\ (p \in [1, + ∞])

whose elements can be described as

K\:(\mathrm{\Omega }) = \{u \in W_{\mathrm{loc}}^{1,\:p}\:(ℝ^{n}):Du\:(x) \in C \text{ for a.e. }x \text{ in }Ω\}

,

C

being a closed convex subset of

ℝ^n

.

Characterizations similar to the above mentioned but for families of subsets of

BV_{\mathrm{loc}}\:(ℝ^{n})

and

L_{\mathrm{loc}}^{p}\:(ℝ^{n})

are also proved.

These results are deduced by a general characterization theorem for families of subsets of a Hausdorff locally convex topological vector subspace of

L_{\mathrm{loc}}^{1}\:(ℝ^{n})

.

An application to the problem of the homogenization of the elastic-plastic torsion of a cylindrical bar is given.

Résumé

Un des résultats démontrés dans notre travail concerne une caractérisation des familles

\{K (Ω) : Ω, \text{ ensemble ouvert borné}\}

des sous-ensembles de

W_{\mathrm{loc}}^{1,\:p}\:(ℝ^{n})\:\:(p \in [1, + ∞])

dont les éléments peuvent être décrits comme

K(\mathrm{\Omega }) = \{u \in W_{\mathrm{loc}}^{1,\:p}\:(ℝ^{n}):Du\:(x) \in C \text{ pour presque chaque }x \text{ en }Ω\}

,

C

étant un sous-ensemble convexe fermé de

ℝ^{n}

.

On prouve aussi des caractérisations similaires pour des familles de sous-ensembles de

BV_{\mathrm{loc}}\:(ℝ^{n})

et de

L_{\mathrm{loc}}^{p}\:(ℝ^{n})

.

Nos résultats sont dérivés par un théorème général de caractérisation pour des familles de sous-ensembles d’un sous-espace vectoriel topologique de Hausdorff localement convexe de

L_{\mathrm{loc}}^{1}\:(ℝ^{n})

.

On donne une application pour le problème d’homogénéisation de la torsion élastoplastique d’une barre cylindrique.
The Cauchy problem for semilinear weakly hyperbolic equations in Hilbert spaces
Authors: D’Ancona Piero 
Published: February 2017

We consider an abstract nonlinear second order equation, whose principal part satisfies some conditions inspired by Oleinik’s conditions on degenerate hyperbolic equations. We prove local existence and regularity results in suitable scales of abstract Sobolev spaces. Several applications to concrete equations are given.

Résumé
On considère une équation abstraite du second ordre, nonlinéaire, dont la partie principale satisfait à des conditions inspirées par celles de Mme Oleinik pour les équations hyperboliques dégénérées. On obtient des résultats d’existence locale et de régularité dans des échelles d’espaces de Sobolev abstraits. Plusieurs applications aux équations concrètes sont données.