bluuebunny/crossref_metadata_2025_split huggingface dataset:
Supramolecular Zinc Phthalocyanine–Imidazolyl Perylenediimide Dyad and Triad: Synthesis, Complexation, and Photophysical Studies
Authors: Céspedes‐Guirao F. Javier , Ohkubo Kei , Fukuzumi Shunichi , Fernández‐Lázaro Fernando , Sastre‐Santos Ángela 
Published: September 2011

AbstractTwo new supramolecular architectures based on zinc phthalocyanine (Pc) and imidazolyl‐substituted perylenediimide (PDI), ZnPc/DImPDI/ZnPc 1 and ZnPc/ImPDI 2, have been prepared. A strong electron‐donor, 8, which contained eight tert‐octylphenoxy groups was synthesized to ensure high solubility, thereby reducing aggregation in solution and providing σ‐donor features while avoiding regioisomeric mixtures. Also, PDI units were functionalized with tert‐octylphenoxy groups at the bay positions, which provide solubility to avoid aggregation in solution, together with one and two imidazole moieties in the amide position, 6 and 4, respectively, to be able to strongly coordinate with the ZnPc complex. Supramolecular complexation studies by 1H NMR spectroscopy and ESI‐MS demonstrate a high coordinative binding constant between imidazole‐substituted 4 or 6 and 8. The same results were confirmed by UV/Vis and fluorescence titration studies. UV/Vis titration studies revealed the formation of a 1:1 complex ZnPc/ImPDI 2 for the systems 8 and 6 and a 2:1 complex ZnPc/DImPDI/ZnPc 1 for the interaction of 8 and 4. The binding constant in both cases was determined to be on the order of 105 M−1. Femtosecond laser flash photolysis measurements provided a direct proof of the charge‐separated state within both supramolecular assemblies by observing the transient absorption band at 820 nm due to the zinc phthalocyanine radical cation. The lifetimes of charge‐separated states are (9.8±3) ns for triad 1 and (3±1) ns for dyad 2. As far as we know, this is the first time that a radical ion pair has been detected in a supramolecular assembled ZnPc–PDI system and has obtained the longest lifetime of a charge‐separated state published for ZnPc–PDI assemblies.
Discrete‐time repetitive controller for time‐delay systems with disturbance observer
Authors: Na Jing , Costa‐Castelló Ramon , Griñó Robert , Ren Xuemei 
Published: September 2011

AbstractA novel discrete‐time repetitive controller design for time‐delay systems subject to a periodic reference and exogenous periodic disturbances is presented. The main idea behind the proposed approach is to take advantage of the plant delay in the controller design, and not to compensate for the effect of this delay. To facilitate this concept, we introduce an appropriate time‐delay and a compensator in a positive feedback connection with the plant, such that a generator for periodic signals is constructed. Then a proportional controller is used to stabilize the closed‐loop system. The tracking control capability is thus guaranteed according to the internal model principle (IMP). In addition, to attenuate external periodic disturbances, a disturbance observer (DO) is developed to simultaneously achieve reference tracking and disturbance rejection. The possible fractional delay due to the digital discretization is handled by using a fractional delay filter approximation. The proposed controller has a simple structure, in which only a proportional parameter and a low‐pass filter are required to be chosen. The closed‐loop stability conditions and a robustness analysis under model uncertainties are studied. Numerical simulations and practical experiments on a servo motor system are conducted to verify the feasibility and simplicity of the proposed controller.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Output regulation of time‐varying nonlinear systems
Authors: Yang Xi , Huang Jie 
Published: September 2011

AbstractThis paper considers the robust output regulation problem for time‐varying nonlinear systems with a time‐varying exosystem. A framework for converting the problem into a stabilization problem of an augmented system is established. The problem is solved for a class of time‐varying output feedback systems with a time‐varying exosystem.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Biofuels: ethics and policy‐making
Authors: Buyx Alena M. , Tait Joyce 
Published: September 2011

AbstractMandatory targets for biofuels have led to their rapid global adoption, but ethical problems with their large‐scale production are widely reported. Research is underway to find new biofuel technologies that mitigate climate change and can be produced sustainably and economically. Following an 18‐month inquiry, the Nuffield Council on Bioethics has developed an ethical framework for biofuels policy‐making. Based on a number of widely held ethical values, six ethical principles are introduced that should be considered in biofuels policy‐making. Many current biofuels policies fail this ethical ‘test’. An overarching ethical standard for biofuels is proposed that includes the protection of human rights and the environment, full life cycle assessment of greenhouse gas emissions, trade principles that are fair, access and benefit‐sharing schemes to encourage equitable distribution of costs and benefits, and instruments to incentivize the development of promising new approaches. The Council goes on to make recommendations for changes to current policy. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Application of an induced field sensor for assessment of electromagnetic exposure from compact fluorescent lamps
Authors: Nadakuduti Jagadish , Douglas Mark , Capstick Myles , Kühn Sven , Kuster Niels 
Published: September 2011

AbstractThe development of scientifically sound instrumentation, methods, and procedures for the electromagnetic exposure assessment of compact fluorescent lamps (CFLs) is investigated. The incident and induced fields from 11 CFLs have been measured in the 10 kHz–1 MHz range, and they are compared with the levels for incandescent and light emitting diode (LED) bulbs. Commercially available equipment was used to measure the incident fields, while a novel sensor was built to assess the induced fields in humans. Incident electric field levels significantly exceed the International Commission on Non‐Ionizing Radiation Protection (ICNIRP) reference levels at close distances for some sources, while the induced fields are within the ICNIRP basic restrictions. This demonstrates the importance of assessing the induced fields rather than the incident fields for these sources. Maximum current densities for CFLs are comparable to the limits (in the range of 9% to 56%), demonstrating the need for measurements to establish compliance. For the frequency range investigated, the induced fields were found to be considerably higher for CFLs than for incandescent light bulbs, while the exposure from the two LED bulbs was low. The proposed instrumentation and methods offer several advantages over an existing measurement standard, and the measurement uncertainty is significantly better than the assessment of electric and magnetic fields at close distances. Bioelectromagnetics 33:166–175, 2012. © 2011 Wiley Periodicals, Inc.
Do bacteria differentiate between degrees of nanoscale surface roughness?
Authors: Bazaka Kateryna , Crawford Russell J. , Ivanova Elena P. 
Published: September 2011

AbstractWhereas the employment of nanotechnology in electronics and optics engineering is relatively well established, the use of nanostructured materials in medicine and biology is undoubtedly novel. Certain nanoscale surface phenomena are being exploited to promote or prevent the attachment of living cells. However, as yet, it has not been possible to develop methods that completely prevent cells from attaching to solid surfaces, since the mechanisms by which living cells interact with the nanoscale surface characteristics of these substrates are still poorly understood. Recently, novel and advanced surface characterisation techniques have been developed that allow the precise molecular and atomic scale characterisation of both living cells and the solid surfaces to which they attach. Given this additional capability, it may now be possible to define boundaries, or minimum dimensions, at which a surface feature can exert influence over an attaching living organism.This review explores the current research on the interaction of living cells with both native and nanostructured surfaces, and the role that these surface properties play in the different stages of cell attachment.
Structure of silk by raman spectromicroscopy: From the spinning glands to the fibers
Authors: Lefèvre Thierry , Paquet‐Mercier François , Rioux‐Dubé Jean‐François , Pézolet Michel 
Published: September 2011

AbstractRaman spectroscopy has long been proved to be a useful tool to study the conformation of protein‐based materials such as silk. Thanks to recent developments, linearly polarized Raman spectromicroscopy has appeared very efficient to characterize the molecular structure of native single silk fibers and spinning dopes because it can provide information relative to the protein secondary structure, molecular orientation, and amino acid composition. This review will describe recent advances in the study of the structure of silk by Raman spectromicroscopy. A particular emphasis is put on the spider dragline and silkworm cocoon threads, other fibers spun by orb‐weaving spiders, the spinning dope contained in their silk glands and the effect of mechanical deformation. Taken together, the results of the literature show that Raman spectromicroscopy is particularly efficient to investigate all aspects of silk structure and production. The data provided can lead to a better understanding of the structure of the silk dope, transformations occurring during the spinning process, and structure and mechanical properties of native fibers. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 322–336, 2012.
A population balance equation model of aggregation dynamics in Taxus suspension cell cultures
Authors: Kolewe Martin E. , Roberts Susan C. , Henson Michael A. 
Published: September 2011

AbstractThe nature of plant cells to grow as multicellular aggregates in suspension culture has profound effects on bioprocess performance. Recent advances in the measurement of plant cell aggregate size allow for routine process monitoring of this property. We have exploited this capability to develop a conceptual model to describe changes in the aggregate size distribution that are observed over the course of a Taxus cell suspension batch culture. We utilized the population balance equation framework to describe plant cell aggregates as a particulate system, accounting for the relevant phenomenological processes underlying aggregation, such as growth and breakage. We compared model predictions to experimental data to select appropriate kernel functions, and found that larger aggregates had a higher breakage rate, biomass was partitioned asymmetrically following a breakage event, and aggregates grew exponentially. Our model was then validated against several datasets with different initial aggregate size distributions and was able to quantitatively predict changes in total biomass and mean aggregate size, as well as actual size distributions. We proposed a breakage mechanism where a fraction of biomass was lost upon each breakage event, and demonstrated that even though smaller aggregates have been shown to produce more paclitaxel, an optimum breakage rate was predicted for maximum paclitaxel accumulation. We believe this is the first model to use a segregated, corpuscular approach to describe changes in the size distribution of plant cell aggregates, and represents an important first step in the design of rational strategies to control aggregation and optimize process performance. Biotechnol. Bioeng. 2012; 109:472–482. © 2011 Wiley Periodicals, Inc.
Value of failure to rescue as a marker of the standard of care following reoperation for complications after colorectal resection
Authors: Almoudaris A M , Burns E M , Mamidanna R , Bottle A , Aylin P , Vincent C , Faiz O 
Published: September 2011

Abstract

Background
Complication management appears to be of vital importance to differences in survival following surgery between surgical units. Failure-to-rescue (FTR) rates have not yet distinguished surgical from general medical complications. The aim of this study was to assess whether variability exists in FTR rates after reoperation for serious surgical complications following colorectal cancer resections in England.

Methods
The Hospital Episode Statistics (HES) database was used to identify patients undergoing primary resection for colorectal cancer between 2000 and 2008 in English National Health Service (NHS) trusts. Units were ranked into quintiles according to overall risk-adjusted mortality. Highest and lowest mortality quintiles were compared with respect to reoperation rates and FTR—surgical (FTR-S) rates. FTR-S was defined as the proportion of patients with an unplanned reoperation who died within the same admission.

Results
Some 144 542 patients undergoing resection for colorectal cancer in 150 English NHS trusts were included. On ranking according to risk-adjusted mortality, rates varied significantly between lowest and highest mortality quintiles (5·4 and 9·3 per cent respectively; P = 0·029). Lowest and highest mortality quintiles had equivalent adjusted reoperation rates (both 4·8 per cent; P = 0·211). FTR-S rates were significantly higher at units within the worst mortality quintile (16·8 versus 11·1 per cent; P = 0·002).

Conclusion
FTR-S rates differed significantly between English colorectal units, highlighting variability in ability to prevent death in this high-risk group. This variability may represent differences in serious surgical complication management. FTR-S represents a readily collectable marker of surgical complication management that is likely to be applicable to other surgical specialties.
Identification and quantification of free radical scavengers in the flower buds of Lonicera species by online HPLC‐DPPH assay coupled with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry
Authors: Li Yan‐Jing , Chen Jun , Li Ying , Li Ping 
Published: September 2011

ABSTRACTFlos Lonicerae, derived from the flower buds of several medicinal Lonicera species, is a commonly used herbal medicine with multiple pharmacological activities, one of the major ones being antioxidant activity. In this study, free radical scavengers in the flower buds of six Lonicera species were screened, identified and quantified by online HPLC‐DPPH (1,1‐diphenyl‐2‐picrylhydrazyl) assay coupled with LC quadrupole time‐of‐flight tandem mass spectrometry (Q‐TOF MS/MS). The antioxidants were firstly screened from the complex plant matrix by the online HPLC‐DPPH assay. Then the active compounds were identified by LC Q‐TOF MS/MS, and the possible fragmentation pathways were proposed. The reactivity of antioxidants available was investigated using an internal standard method by online LC assay. The contents of 12 antioxidants were also determined or estimated by HPLC coupled with diode array detector. The total antioxidant capability determined by the online method was used as the marker to evaluate the quality of Flos Lonicerae. The results were important to clarify the material basis and therapeutic mechanism of Flos Lonicerae. Copyright © 2011 John Wiley & Sons, Ltd.
An anatomical investigation of the cervicothoracic ganglion
Authors: Marcer N. , Bergmann M. , Klie A. , Moor B. , Djonov V. 
Published: September 2011

AbstractAnatomical variability within the autonomic nervous system has long been accepted. This study evaluated the anatomical variability of the cervicothoracic ganglion (CTG) according to its form and, in addition, provided precise measurements between the CTG and the anterior tubercle of the transverse process of the sixth cervical vertebra (C6TP), the first costovertebral articulation, and the vertebral artery. Forty‐two adult cadavers were dissected, 22 male and 20 females. Five main forms of CTG were documented; spindle (31.9%), dumbbell (23.2%), truncated (21.7%), perforated (14.5%), and inverted‐L (8.7%). The means for length, width, and thickness of the CTG were 18.5 mm, 8.2 mm, and 4.5 mm, respectively. The dimensions were found to be slightly larger in the males than females and on the left sides as compared to the right. The mean shortest distance between the CTGs and the vertebral artery was found to be 2.8 mm, whilst the mean shortest distances to C6TP was 25.7 mm and to the first costovertebral articulation was 1.7 mm. There is great variability in the morphology of the CTG with five common forms consistently seen. The relation to the vertebral artery may influence the form of the ganglion. Two previously undocumented forms are recorded; the truncated which describes the important juxtaposition of the CTG and the vertebral artery and the perforated which describes the piercing of the ganglion itself by the artery. The findings are considered to be of clinical importance to anesthetists, surgeons, neurosurgeons, and anatomists. Clin. Anat. 25:444–451, 2012. © 2011 Wiley Periodicals, Inc.
Designing and implementing a constructionist approach for improving the teaching–learning process in the embedded systems and wireless communications areas
Authors: Garcia I. A. , Cano E. M. 
Published: September 2011

AbstractNowadays, there has been a real change in the traditional (Mexican) methodology for learning and teaching; the teaching of electronic sciences needs to identify the real necessities of students to avoid deficiencies in static classrooms. The benefits of the constructionist theory as a learning paradigm are widely recognized, because they support significant learning environments where students are actively related in implementing their own public artifacts; passing through passive to active learning states. Thus, the constructionist theory stresses the need to understand the student's thinking and to encourage them to reflect on their models as a means to improve them. This article aims to show the results derived from developing a constructionist platform for embedded systems and wireless communications education, using a dedicated methodology based on the constructionist theory. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22:481–493, 2014; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.10.1002/cae.20574
Brand personality, self‐congruity, and preference: A knowledge structures approach
Authors: Branaghan Russell J. , Hildebrand Emily A. 
Published: September 2011

AbstractUsing the construct of brand personality to measure automobile and soft drink personalities, two studies represented self‐congruity by combining brands and the self‐image into Pathfinder associative networks (Schvaneveldt et al., 1989). Self‐congruity, the number of links between the self and each brand, was predictive of preference and ideal brand. Because brand personality and self‐image are knowledge structures, and facets of brand personality also describe the self, self‐congruity can be represented and measured in networks. This approach could be helpful to marketers studying how the self is related to each brand and how brands interrelate. Copyright © 2011 John Wiley & Sons, Ltd.
Dynamic‐Light‐Scattering‐Based Sequence‐Specific Recognition of Double‐Stranded DNA with Oligonucleotide‐Functionalized Gold Nanoparticles
Authors: Miao Xiang‐Min , Xiong Cen , Wang Wei‐Wei , Ling Lian‐Sheng , Shuai Xin‐Tao 
Published: September 2011

AbstractAn ultrasensitive and simple dynamic‐light‐scattering (DLS) assay for the sequence‐specific recognition of double‐stranded DNA (dsDNA) was developed based on detection of the average diameter change of Au nanoparticle (AuNP) probes modified with oligonucleotides 5′‐TTTCTCTTCCTT‐ CTCTTC‐(T)12‐SH‐3′ (Oligo 1) and 5′‐TTCTTTCTTTTCTTTTTC‐(T)12‐ SH‐3′ (Oligo 2). The target dsDNA was composed of two complementary oligonucleotides: 5′‐AAAGAGAAGGAAGAGAAGAAGAAAGAAAAGAAAAAG‐3′ (Oligo 3) and 3′‐TTTCTCTTCCTTCTCTTCTTCTTTCTTTTCTTTTTC‐5′ (Oligo 4). Hybridization of the two AuNPs–Oligo probes with the target dsDNA induced aggregation of the target dsDNA by forming triplex DNA, which accordingly increased the average diameter. This diameter change could then be detected by DLS. The average diameter was proportional to the target dsDNA concentration over the range from 593 fM to 40 pM, with a detection limit of 593 fM. Moreover, the assay had good sequence specificity for the target dsDNA.
Photochemical Switching of the Phase‐Transition Temperatures of p‐NIPAM–Pt Nanoparticles Thermosensitive Polymer Composites Associated with Electrodes: Functional Electrodes for Switchable Electrocatalysis
Authors: Zhang Junji , Riskin Michael , Tel‐Vered Ran , Tian He , Willner Itamar 
Published: September 2011

AbstractThe thermosensitive poly(N‐isopropylacrylamide) (p‐NIPAM) is electropolymerized onto Au surfaces. The incorporation of the photoisomerizable N‐carboxyethyl nitrospiropyran compound into p‐NIPAM allows the reversible photochemical control of the gel‐to‐solid phase‐transition temperatures of the polymer. Whereas the gel‐to‐solid phase‐transition temperature of the nitrospiropyran‐modified p‐NIPAM is 33±2 °C, the phase‐transition temperature of the nitromerocyanine‐functionalized p‐NIPAM matrix corresponds to 38±1 °C. Upon the incorporation of Pt nanoparticles (NPs) into the photochemically controlled p‐NIPAM, a hybrid photoswitchable electrocatalytic matrix is formed. At a fixed temperature corresponding to 38 °C, the effective electrocatalytic reduction of H2O2, or the oxidation of ascorbic acid, proceeded in the presence of the nitromerocyanine‐functionalized p‐NIPAM, yet these electrocatalytic transformations were inhibited in the presence of the nitrospiropyran‐modified p‐NIPAM.
Polystyrene‐Supported Diarylprolinol Ethers as Highly Efficient Organocatalysts for Michael‐Type Reactions
Authors: Alza Esther , Sayalero Sonia , Kasaplar Pinar , Almaşi Diana , Pericàs Miquel A. 
Published: September 2011

Abstractα,α‐Diphenylprolinol methyl‐ and trimethylsilyl ethers anchored onto a polystyrene resin have been prepared by a copper‐catalyzed azide–alkyne cycloadditions (CuAAC). The catalytic activity and enantioselectivity displayed by the O‐trimethylsilyl derivative are comparable to those exhibited by the best known homogeneous catalysts for the addition of aldehydes to nitroolefins and of malonates or nitromethane to α,β‐unsaturated aldehydes. The combination of the catalytic unit, the triazole linker, and the polymeric matrix provides unprecedented substrate selectivity, in favor of linear, short‐chain aldehydes, when the organocatalyzed reaction proceeds by an enamine mechanism. High versatility is noted in reactions that proceed via an iminium ion intermediate. The catalytic behavior of polystyrene‐supported α,α‐diphenylprolinol methyl ether was also evaluated in asymmetric Michael addition reactions. As a general trend, the CuAAC immobilization of diarylprolinol ethers onto insoluble polystyrene resins offers important operational advantages, such as high catalytic activity, easy recovery from the reaction mixture by simple filtration, and the possibility of extended reuse.
ChemInform Abstract: Partial Inverse Spinel Structure of Manganese‐Doped Gahnite: XRD and EPR Spectroscopy Studies.
Authors: Popovic J. , Grzeta B. , Rakvin B. , Tkalcec E. , Vrankic M. , Kurajica S. 
Published: September 2011

AbstractMn‐doped ZnAl2O4 with 0, 4.3, 7.6, and 11.7 at.% Mn (substituted for Zn) is synthesized by a sol—gel process starting with a mixture of Al(O‐sBu)3, Zn(NO3)2, Mn(NO3)2 dissolved in sBuOH (calcination in air, 800 °C, 2 h).
ChemInform Abstract: Relativistic Effects and Gold Site Distributions: Synthesis, Structure, and Bonding in a Polar Intermetallic Na6Cd16Au7.
Authors: Samal Saroj L. , Corbett John D. 
Published: September 2011

AbstractThe title compound is synthesized from stoichiometric amounts of the elements (Ta container, 600 °C, 15 h) and characterized by powder and single crystal XRD, and LMTO‐ASA electronic structure calculations.