bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Spacer Connecting the Secondary Electron Donor Phenothiazine in Subphthalocyanine–Fullerene Conjugates in Promoting Electron Transfer Followed by Hole Shift Process
Authors: KC Chandra B. , Lim Gary N. , D'Souza Francis 
Published: April 2016

AbstractSequential electron/hole transfer between energetically well‐positioned entities of photosynthetic reaction center models is one of the commonly employed mechanisms to generate long‐lived charge‐separated states. A wealth of information, applicable towards light energy harvesting and building optoelectronic devices, has been acquired from such studies. In the present study, we report on the effect of spacer (direct or via phenoxy linkage) connecting the hole shifting agent, phenothiazine (PTZ), on photoinduced charge stabilization in subphthalocyanine–fullerene donor–acceptor conjugates. In these conjugates, the subphthalocyanine (SubPc) and fullerene (C60) served as primary electron donor and acceptor, respectively, while the phenothiazine entities act as hole shifting agents. The newly synthesized compounds were characterized by optical absorption and emission, computational, and electrochemical methods. The redox potentials measured using differential pulse voltammetry were used to estimate free‐energy changes for charge separation, hole migration, and charge recombination processes. Using femto‐ and nanosecond transient absorption techniques, evidence for charge separation, and kinetics of charge separation and recombination were obtained in polar benzonitrile and nonpolar toluene solvents. In the conjugate where the phenothiazine entities are directly linked to SubPc, evidence for sequential electron transfer followed by hole shift leading to long‐lived charge separated state was weak, primarily due to the delocalization of HOMO on both SubPc and PTZ entities. However, in case of the conjugate where the PTZ and SubPc are linked via phenoxy spacers, sequential electron transfer/hole shift was observed leading to the formation of long‐lived charge‐separated states. The present study brings out the importance of the spacer group connecting the hole shifting agent in model donor–acceptor conjugates to generate long‐lived charge‐separated states.
Ligand‐Free, Cu‐ and Fe‐Catalyzed Selective Ring‐Opening Arylations of Benzoxazoles with Aryl Iodides
Authors: He Yue , Mao Jincheng , Rong Guangwei , Yan Hong , Zhang Guoqi 
Published: April 2016

AbstractCu‐ or Fe‐based catalyst systems have been reported to selectively catalyze the N,N‐diarylation or N‐monoarylation of benzoxazoles ring‐opening with aryl iodides in the absence of additional added ligand in polyethylene glycol under an inert atmosphere. Two types of coupling products (triphenylamines and diphenylamines) have been examined and the reaction routes can be simply controlled by changing the metal salts (Cu or Fe) as catalyst. A range of substrates have been investigated for the diverse reactions, and the corresponding arylation products were achieved in good to high yields. This selective, low‐cost, and environmentally friendly protocol displays great potential for replacing existing methodologies as well as extending the synthetic applications of benzoxazoles.
Trajectory Tracking Control of an Underactuated Underwater Vehicle Redundant Manipulator System
Authors: Korkmaz Ozan , Ider S. Kemal , Ozgoren M. Kemal 
Published: April 2016

AbstractThe purpose of this study is to control the position of an underactuated underwater vehicle manipulator system (U‐UVMS). It is possible to control the end‐effector using a regular 6‐DOF manipulator despite the undesired displacements of the underactuated vehicle within a certain range. However, in this study an 8‐DOF redundant manipulator is used in order to increase the positioning accuracy of the end‐effector. The redundancy is resolved according to the criterion of minimal vehicle and joint motions. The underactuated underwater vehicle redundant manipulator system is modeled including the hydrodynamic forces for the manipulator in addition to those for the autonomous underwater vehicle (AUV). The shadowing effects of the bodies on each other are also taken into account when computing the hydrodynamic forces. The Newton‐Euler formulation is used to derive the system equations of motion including the thruster dynamics. In order to establish the end‐effector trajectory tracking control of the system, an inverse dynamics control law is formulated. The effectiveness of the control law even in the presence of parameter uncertainties and disturbing ocean currents is illustrated by simulations.
Embedded MPC Controller Based on Interior‐Point Method with Convergence Depth Control
Authors: Ding Yi , Xu Zuhua , Zhao Jun , Wang Kexin , Shao Zhijiang 
Published: April 2016

AbstractTo allow the implementation of model predictive control on the chip, we first propose a primal–dual interior point method with convergence depth control to solve the quadratic programming problem of model predictive control. Compared with algorithms based on traditional termination criterion, the proposed method can significantly reduce the computation cost while obtaining an approximate solution of the quadratic programming problem with acceptable optimality and precision. Thereafter, an embedded model predictive controller based on the quadratic programming solver is designed and implemented on a digital signal processor chip and a prototype system is built on a TMDSEVM6678LE digital signal processor chip. The controller is verified on two models by using the hardware in loop frame to mimic real applications. The comparison shows that the whole design is competitive in real‐time applications. The typical computation time for quadratic programming problems with 5 decision variables and 110 constraints can be reduced to less than 2 ms on an embedded platform.
Hierarchical Control of Linear Systems from the Abstraction Feedback Gain
Authors: Kaihong Yang , Haibo Ji 
Published: April 2016

AbstractIn this paper, the problem of hierarchical control for a class of linear systems is addressed. Given a large‐scale linear system, we obtain a stabilizing feedback gain for it from that of an abstract system. And then, we employ this feedback gain to design a new interface between the original system and the abstraction. Furthermore, the synthesis of the new interface can be allowed by a new simulation function characterized by a low‐order matrix associated to the abstraction. Finally, an example is given to illustrate the proposed approach.
Targeted DNA delivery to cancer cells using a biotinylated chitosan carrier
Authors: Darvishi Mohammad H. , Nomani Alireza , Hashemzadeh Hadi , Amini Mohsen , Shokrgozar Mohammad A. , Dinarvand Rassoul 
Published: April 2016

AbstractA novel biotinylated chitosan‐graft‐polyethyleneimine (Bio‐Chi‐g‐PEI) copolymer was synthesized and evaluated as a nonviral gene delivery carrier for improvement of the transfection efficiency, endosomal escape, and targeted gene delivery of a plasmid encoding green fluorescent protein N1 (pEGFP‐N1) into two different biotin‐overexpressing cell lines including HeLa and OVCAR‐3 cells. The structure of the obtained copolymers was confirmed by 1H nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy. Physicochemical properties of the Bio‐Chi‐g‐PEI/plasmid DNA (pDNA) complexes such as complex stability, size, zeta potential, and their morphology were investigated at various weight ratios of copolymer to pDNA. Bio‐Chi‐g‐PEI copolymers could effectively condense pDNA into small particles with average diameters less than 164 nm and the zeta potential of +34.8 mV at the N/P ratio of 40/1. As revealed by flow cytometry, Bio‐Chi‐g‐PEI/pDNA complexes had lower cytotoxicity than that of PEI 25 kDa/pDNA complexes in both cell lines. In vitro experiments revealed that the Bio‐Chi‐gPEI/pDNA complexes not only had much lower cytotoxicity, but also displayed higher transfection efficiency than that of PEI 25kDa/pDNA complexes. High percentage of cancer cells was successfully transfected by Bio‐Chi‐g‐PEI/pDNA and properly expressed GFP protein. This study indicates that this copolymer complex can be a promising gene delivery carrier.
An Expectancy Theory Approach to Group Coordination: Expertise, Task Features, and Member Behavior
Authors: Baumann Michael R. , Bonner Bryan L. 
Published: April 2016

AbstractWorking in a group requires coordination. The current paper examines coordination in terms of member‐level behavioral choices. Extending expectancy theory to a collaborative group setting, we interpret past findings on expertise and hypothesize that component features (specifically their difficulty and worth relative to each other) impact member behavior and hence coordination both directly and by moderating the role of expertise. Findings were largely as predicted, suggesting that an expectancy theory perspective may be a useful tool for the study and understanding of coordination. An exploratory examination of recordings of group interaction suggested that although most of our groups discussed coordination strategies, the strategies discussed did not generally map to the behavioral choices observed. Implications for coordination in general and transactive memory specifically are discussed. Copyright © 2016 John Wiley & Sons, Ltd.
The Selection of Freebies and the Preference for Freebie Promotions—A Perspective on Item Characteristics
Authors: Liu Hsin‐Hsien , Chou Hsuan‐Yi 
Published: April 2016

AbstractResearch on consumer decision making has mainly focused on individual products; however, many products are purchased with other items as part of a promotional package. This paper explores how the characteristics (hedonic versus utilitarian) of the items in freebie promotional packages (e.g., buy one item and get a different item for free) influence consumers' preference for the promotional package. Additionally, the authors examine how the characteristics of the focal item influence consumers' choice of either a hedonic or a utilitarian freebie item. Five experiments, rooted in the concepts of consumer avoidance of overloading negative emotions and motivation to seek hedonic pleasure, show that a package with one utilitarian and one hedonic item generates higher purchase intentions and willingness to pay than a package with either two hedonic or two utilitarian items. Furthermore, consumers who purchase a hedonic (utilitarian) focal item are more likely to choose a utilitarian (hedonic) freebie. These effects exist not only in hypothetical scenarios but also in an incentive‐compatible design. Moreover, the impact of the focal item characteristics on consumer choice of freebie is moderated by acquisition format and time separation. The authors also explore the internal mechanism influencing consumers' freebie choices. The findings have significant implications for both theory and practice. Copyright © 2016 John Wiley & Sons, Ltd.
Invited review: Architectures and mechanisms of ATP binding cassette proteins
Authors: Hopfner Karl‐Peter 
Published: April 2016

ABSTRACTATP binding cassette (ABC) ATPases form chemo‐mechanical engines and switches that function in a broad range of biological processes. Most prominently, a very large family of integral membrane NTPases—ABC transporters—catalyzes the import or export of a diverse molecules across membranes. ABC proteins are also important components of the chromosome segregation, recombination, and DNA repair machineries and regulate or catalyze critical steps of ribosomal protein synthesis. Recent structural and mechanistic studies draw interesting architectural and mechanistic parallels between diverse ABC proteins. Here, I review this state of our understanding how NTP‐dependent conformational changes of ABC proteins drive diverse biological processes. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 492–504, 2016.
Identification of non‐random sequence properties in groups of signature peptides obtained in random sequence peptide microarray experiments
Authors: Kuznetsov Igor B. 
Published: April 2016

ABSTRACTImmunosignaturing is an emerging experimental technique that uses random sequence peptide microarrays to detect antibodies produced by the immune system in response to a particular disease. Two important questions regarding immunosignaturing are “Do microarray peptides that exhibit a strong affinity to a given type of antibodies share common sequence properties?” and “If so, what are those properties?” In this work, three statistical tests designed to detect non‐random patterns in the amino acid makeup of a group of microarray peptides are presented. One test detects patterns of significantly biased amino acid usage, whereas the other two detect patterns of significant bias in the biochemical properties. These tests do not require a large number of peptides per group. The tests were applied to analyze 19 groups of peptides identified in immunosignaturing experiments as being specific for antibodies produced in response to various types of cancer and other diseases. The positional distribution of the biochemical properties of the amino acids in these 19 peptide groups was also studied. Remarkably, despite the random nature of the sequence libraries used to design the microarrays, a unique group‐specific non‐random pattern was identified in the majority of the peptide groups studied. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 318–329, 2016.
Redoubling the ring size of an endomorphin‐2 analog transforms a centrally acting mu‐opioid receptor agonist into a pure peripheral analgesic
Authors: Piekielna Justyna , De Marco Rossella , Gentilucci Luca , Cerlesi Maria Camilla , Calo' Girolamo , Tömböly Csaba , Artali Roberto , Janecka Anna 
Published: April 2016

ABSTRACTThe study reports the synthesis and biological evaluation of two opioid analogs, a monomer and a dimer, obtained as products of the solid‐phase, side‐chain to side‐chain cyclization of the pentapeptide Tyr‐d‐Lys‐Phe‐Phe‐AspNH2. The binding affinities to the mu, delta, and kappa opioid receptors, as well as results obtained in a calcium mobilization functional assay are reported. Tyr‐[d‐Lys‐Phe‐Phe‐Asp]2‐NH2 1 was a potent and selective full agonist of mu with sub‐nanomolar affinity, while the dimer (Tyr‐[d‐Lys‐Phe‐Phe‐Asp]2‐NH2)2 2 showed a significant mixed mu/kappa affinity, acting as an agonist at the mu. Molecular docking computations were utilized to explain the ability of the dimeric cyclopeptide 2 to interact with the receptor. Interestingly, in spite of the increased ring size, the higher flexibility allowed 2 to fold and fit into the mu receptor binding pocket. Both cyclopeptides were shown to elicit strong antinociceptive activity after intraventricular injection but only cyclomonomer 1 was able to cross the blood–brain barrier. However, the cyclodimer 2 displayed a potent peripheral antinociceptive activity in a mouse model of visceral inflammatory pain. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 309–317, 2016.
Conformational flexibility of aspartame
Authors: Toniolo Claudio , Temussi Pierandrea 
Published: April 2016

ABSTRACTL‐Aspartyl‐L‐phenylalanine methyl ester, better known as aspartame, is not only one of the most used artificial sweeteners, but also a very interesting molecule with respect to the correlation between molecular structure and taste. The extreme conformational flexibility of this dipeptide posed a huge difficulty when researchers tried to use it as a lead compound to design new sweeteners. In particular, it was difficult to take advantage of its molecular model as a mold to infer the shape of the, then unknown, active site of the sweet taste receptor. Here, we follow the story of the 3D structural aspects of aspartame from early conformational studies to recent docking into homology models of the receptor. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 376–384, 2016.
Effects of linker sequence modifications on the structure, stability, and biological activity of a cyclic α‐conotoxin
Authors: Carstens Bodil B. , Swedberg Joakim , Berecki Géza , Adams David J. , Craik David J. , Clark Richard J. 
Published: April 2016

AbstractThe cyclic conotoxin analogue cVc1.1 is a promising lead molecule for the development of new treatments for neuropathic and chronic pain. The design of this peptide includes a linker sequence that joins the N and C termini together, improving peptide stability while maintaining the structure and activity of the original linear Vc1.1. The effect of linker length on the structure, activity and stability of cyclised conotoxins has been studied previously but the effect of altering the composition of the linker sequence has not been investigated. In this study, we designed three analogues of cVc1.1 with linker sequences that varied in charge, hydrophobicity and hydrogen bonding capacity and examined the effect on structure, stability, membrane permeability and biological activity. The three designed peptides were successfully synthesized using solid phase peptide synthesis approaches and had similar structures and stability compared with cVc1.1. Despite modifications in charge, hydrophobicity and hydrogen bonding potential, which are all factors that can affect membrane permeability, no changes in the ability of the peptides to pass through membranes in either PAMPA or Caco‐2 cell assay were observed. Surprisingly, modification of the linker sequence was deleterious to biological activity. These results suggest the linker sequence might be a useful part of the molecule for optimization of bioactivity and not just the physiochemical properties of cVc1.1. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 864–875, 2016.
Bioanalysis of antihistamines for clinical or forensic purposes
Authors: Katselou Maria , Papoutsis Ioannis , Nikolaou Panagiota , Spiliopoulou Chara , Athanaselis Sotiris 
Published: April 2016

AbstractAntihistamines are a class of drugs that inhibit the action of histamine and are used to alleviate symptoms associated with allergic reactions, but some of them can cause side effects, the most unpleasant and dangerous of which are the sedative effects that may hinder important psychological functions and impair skilled performance. These side effects could decrease safety in certain common and critical tasks, such as driving or operating machinery, leading to accidents. Antihistamines can also cause intoxications, sometimes lethal, especially when co‐administered with alcohol or other sedative drugs. Thus, the development of analytical methods for their determination in biological fluids is considered to be useful for the investigation of clinical and forensic cases. These methodologies could also be used for pharmacokinetic studies. Several liquid and a few gas chromatographic methods have been developed for the determination of antihistamines in biological matrices after proper pretreatment procedures. This article reviews the published analytical methodologies that were gathered through the search in PubMed database and the recent developments on isolation or determination of antihistamines in biological materials. Current trends and future perspectives on bioanalysis of antihistamines are also discussed. Copyright © 2016 John Wiley & Sons, Ltd.
Compatible stability study of panax notoginseng saponin injection (xueshuantong®) in combination with 47 different injectables
Authors: Wang Meng , Zhang Huijie , Dong Ranran , Tan Lejun , Liu Zhidong , Zhu Yan , Gao Xiumei , Ren Xiaoliang 
Published: April 2016

AbstractPanax Notoginseng Saponin (PNS) injection (Xueshuantong®, XST) plays an important role in acute and chronic treatment of cardiovascular disease in China. XST, a freeze‐dried powder injection of PNS, contains ginsenosides, Rg1, Rb1, Re, Rd. and notoginsenoside, R1. Study of the stability of herbal medicine injections is limited. The degradation products may contribute to adverse drug reactions (ADRs). The stability kinetics and degradation mechanisms of the five ingredients of PNS in XST injection were systematically explored in aqueous solution. The compatible stability of XST injection in combination with 47 injectables was evaluated using biophysical analysis. A principal components analysis model provided a good clustering result after compatibility. The degradation of the five ingredients in aqueous solution was found to be acid, temperature, oxidation and trivalent ion‐dependent. All ingredients were much more stable in XST injection than in aqueous solutions. Nine degradation products were identified by adopting LC‐Q‐TOF/MS. Standards exceeding the osmotic pressure and/or particle size were found to be the probable causes of the ADR, which were related to drug combination. To minimize the risk of ADRs, drug combinations should be avoided until the complicated chemical matrices of the Chinese medicine injections are more clearly understood. Copyright © 2016 John Wiley & Sons, Ltd.
Quantitative determination of regorafenib and its two major metabolites in human plasma with high‐performance liquid chromatography and ultraviolet detection
Authors: Fujita Kazuma , Miura Masatomo , Shibata Hiroyuki 
Published: April 2016

AbstractA simple, highly sensitive and specific high‐performance liquid chromatography (HPLC) method was developed for the simultaneous quantitation of regorafenib, N‐oxidemetabolite (M‐2) and the desmethyl N‐oxide metabolite (M‐5) in human plasma. Regorafenib, M‐2, M‐5 and the internal standard sorafenib were separated using a mobile phase of 0.5% KH2PO4 (pH 3.5)–acetonitrile (30:70, v/v), on a Capcell PAK MG II column at a flow rate of 0.5 mL/min and measurement at UV 260 nm. The lower limits of quantification for regorafenib, M‐2 and M‐5 were 10 ng/mL for each analyte. A procedure using solid‐phase extraction required only a small amount of plasma (100 μL) for one analysis while providing high extraction recovery (>81% for all compounds) and good selectivity. Coefficients of variation for intra‐ and inter‐day assays were <12.2% for regorafenib, <12.3% for M‐2 and <15.1% for M‐5. Accuracies for intra‐ and inter‐day assays were <9.4% for regorafenib, <8.0% for M‐2 and <12.8% for M‐5 over a linear range from 10 to 10,000 ng/mL. This HPLC assay is suitable for clinical pharmacokinetic studies of regorafenib. The present HPLC method is currently in use for our observational studies of patients under treatment. Copyright © 2016 John Wiley & Sons, Ltd.
Predicting human intestinal absorption in the presence of bile salt with micellar liquid chromatography
Authors: Waters Laura J. , Shokry Dina S. , Parkes Gareth M.B. 
Published: April 2016

AbstractUnderstanding intestinal absorption for pharmaceutical compounds is vital to estimate the bioavailability and therefore the in vivo potential of a drug. This study considers the application of micellar liquid chromatography (MLC) to predict passive intestinal absorption with a selection of model compounds. MLC is already known to aid prediction of absorption using simple surfactant systems; however, with this study the focus was on the presence of a more complex, bile salt surfactant, as would be encountered in the in vivo environment. As a result, MLC using a specific bile salt has been confirmed as an ideal in vitro system to predict the intestinal permeability for a wide range of drugs, through the development of a quantitative partition–absorption relationship. MLC offers many benefits including environmental, economic, time‐saving and ethical advantages compared with the traditional techniques employed to obtain passive intestinal absorption values. Copyright © 2016 John Wiley & Sons, Ltd.