bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrochemical Monitoring of Nucleic Acid Hybridization by Single‐Use Graphene Oxide‐Based Sensor
Authors: Muti Mihrican , Sharma Surbhi , Erdem Arzum , Papakonstantinou Pagona
Published: December 2010

In this paper, the application of a Graphene oxide (GRPox) integrated on single‐use pencil graphite electrode (PGE) for the enhanced monitoring of nucleic acids and for the sensitive and selective detection of the label free DNA hybridization related to Hepatitis B virus (HBV) sequences is described. Electrochemical behaviors of GRPox modified PGEs were firstly investigated using electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). The sequence selective DNA hybridization was determined voltammetrically in the case of hybridization between amino linked probe and its complementary (target), or, noncomplementary (NC), or target/mismatch (MM) mixtures (1 : 1).
Chemical Speciation of Antimony(III and V) in Water by Adsorptive Cathodic Stripping Voltammetry Using the 4‐(2‐Thiazolylazo) – Resorcinol
Authors: El‐Shahawi M. S. , Bashammakh A. S. , Al‐Sibaai A. A. , Bahaffi S. O. , Al‐Gohani E. H.
Published: December 2010

A simple adsorptive cathodic stripping voltammetry method has been developed for antimony (III and V) speciation using 4‐(2‐thiazolylazo) – resorcinol (TAR). The methodology involves controlled preconcentration at pH 5, during which antimony(III) – TAR complex is adsorbed onto a hanging mercury drop electrode followed by measuring the cathodic peak current (Ip,c) at −0.39 V versus Ag/AgCl electrode. The plot of Ip,c versus antimony(III) concentration was linear in the range 1.35×10−9–9.53×10−8 mol L−1.The LOD and LOQ for Sb(III) were found 4.06×10−10 and 1.35×10−9 mol L−1, respectively. Antimony(V) species after reduction to antimony(III) with Na2SO3 were also determined. Analysis of antimony in environment water samples was applied satisfactorily.
Sex differences in neural responses to stress and alcohol context cues
Authors: Seo Dongju , Jia Zhiru , Lacadie Cheryl M. , Tsou Kristen A. , Bergquist Keri , Sinha Rajita
Published: December 2010

Stress and alcohol context cues are each associated with alcohol‐related behaviors, yet neural responses underlying these processes remain unclear. This study investigated the neural correlates of stress and alcohol context cue experiences and examined sex differences in these responses. Using functional magnetic resonance imaging, brain responses were examined while 43 right‐handed, socially drinking, healthy individuals (23 females) engaged in brief guided imagery of personalized stress, alcohol‐cue, and neutral‐relaxing scenarios. Stress and alcohol‐cue exposure increased activity in the cortico–limbic–striatal circuit (P< 0.01, corrected), encompassing the medial prefrontal cortex (mPFC), orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), left anterior insula, striatum, and visuomotor regions (parietal and occipital lobe, and cerebellum). Activity in the left dorsal striatum increased during stress, while bilateral ventral striatum activity was evident during alcohol‐cue exposure. Men displayed greater stress‐related activations in the mPFC, rostral ACC, posterior insula, amygdala, and hippocampus than women, whereas women showed greater alcohol‐cue‐related activity in the superior and middle frontal gyrus (SFG/MFG) than men. Stress‐induced anxiety was positively associated with activity in emotion‐modulation regions, including the medial OFC, ventromedial PFC, left superior‐mPFC, and rostral ACC in men, but in women with activation in the SFG/MFG, regions involved in cognitive processing. Alcohol craving was significantly associated with the striatum (encompassing dorsal, and ventral) in men, supporting its involvement in alcohol “urge” in healthy men. These results indicate sex differences in neural processing of stress and alcohol‐cue experiences and have implications for sex‐specific vulnerabilities to stress‐ and alcohol‐related psychiatric disorders. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.
Finding your voice: A singing lesson from functional imaging
Authors: Wilson Sarah J. , Abbott David F. , Lusher Dean , Gentle Ellen C. , Jackson Graeme D.
Published: December 2010

Vocal singing (singing with lyrics) shares features common to music and language but it is not clear to what extent they use the same brain systems, particularly at the higher cortical level, and how this varies with expertise. Twenty‐six participants of varying singing ability performed two functional imaging tasks. The first examined covert generative language using orthographic lexical retrieval while the second required covert vocal singing of a well‐known song. The neural networks subserving covert vocal singing and language were found to be proximally located, and their extent of cortical overlap varied with singing expertise. Nonexpert singers showed greater engagement of their language network during vocal singing, likely accounting for their less tuneful performance. In contrast, expert singers showed a more unilateral pattern of activation associated with reduced engagement of the right frontal lobe. The findings indicate that singing expertise promotes independence from the language network with decoupling producing more tuneful performance. This means that the age‐old singing practice of ‘finding your singing voice’ may be neurologically mediated by changing how strongly singing is coupled to the language system. Hum Brain Mapp, 2011. © 2010 Wiley Periodicals, Inc.
Regional variations in medical spending and utilization: a longitudinal analysis of US Medicare population
Authors: Rettenmaier Andrew J. , Wang Zijun
Published: December 2010

One of the perceived symptoms of US Medicare inefficiency is the existence of the dramatic variation in spending and utilization in different areas of the country. This study uses the Continuous Medicare History Sample, a large longitudinal 5% sample of all Medicare beneficiaries from 1974 to 2003, to study the issue. We show that the spending and utilization disparities are significant at the aggregate state level. More importantly, the variation shows signs of narrowing over time, particularly in the earlier years of the sample period and in some cases following major reforms. However, it remains significant even after an array of demographic, demand and supply side factors are controlled for. Copyright © 2010 John Wiley & Sons, Ltd.
Surgical salvage nasopharyngectomy for recurrent nasopharyngeal carcinoma: A multivariate analysis of prognostic factors
Authors: Vlantis Alexander C. , Chan Hing Sang , Tong Michael C. F. , Yu Brian K. H. , Kam Michael K. M. , van Hasselt C. Andrew
Published: December 2010

Background

The purpose of this study was to identify independent prognostic factors that influenced local relapse‐free survival (LRFS) and overall survival (OS) of patients who underwent salvage surgery for residual or recurrent nasopharyngeal carcinoma (NPC).

Methods

Ninety‐seven patients who had been treated with radiotherapy or chemoradiotherapy for NPC underwent a nasopharyngectomy for a residual or recurrent local tumor between November 1987 and June 2007. The subsequent minimum follow‐up was 2 years. Univariate and multivariate analyses were performed to identify prognostic factors for LRFS and OS.

Results

The 5‐year LRFS and OS was 46.7% and 51.9%, respectively. On multivariate analysis for LRFS and OS, respectively, recurrent regional disease (hazard ratio [HR], 3.245; p = .008) and (HR, 4.990; p = .001), and positive surgical margins (HR, 5.963; p = .000), and (HR, 4.912; p = .000) were independent prognostic factors.

Conclusion

In patients undergoing surgical salvage nasopharyngectomy for residual or recurrent NPC, positive surgical margins have an independent negative influence on LRFS and OS. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Triterpenoids and Iridoid Glycosides from Gentiana dahurica
Authors: Fan Hui , Zang Yi , Zhang Yi , Zhang Hong‐Feng , Zhao Zheng , Hu Jin‐Feng
Published: December 2010

One new and six known pentacyclic triterpenoids, 1 and 4–9, resp., along with two new and three known iridoid glycosides, 2 and 3, and 10–12, resp., were isolated from the roots of Gentiana dahurica (‘Qin‐Jiao’). The new structures were elucidated by means of spectroscopic and chemical methods as 1β,2α,3α,24‐tetrahydroxyursa‐12,20(30)‐dien‐28‐oic acid (1), 6′‐O‐acetylgentiopicroside (2), and 3′‐acetylgentiopicroside (3). Isolated compounds were tested for their cytotoxicity against the MCF‐7 human breast cancer cell line using the MTT assay. Among them, triterpenoids 2α,3β,24‐trihydroxyurs‐12‐en‐28‐oic acid (6) and 3β,24‐dihydroxyurs‐12‐en‐28‐oic acid (9) were found to have moderate cytotoxic effects with IC50 values of 20.9 and 21.7 μg/ml, respectively. Additionally, the chemotaxonomic significance of the identified secondary metabolites is briefly discussed.
α‐Cyclodextrin Host–Guest Binding: A Computational Study of the Different Driving Forces
Authors: Riniker Sereina , Daura Xavier , van Gunsteren Wilfred F.
Published: December 2010

Free‐energy differences govern the equilibrium between bound and unbound states of a host and its guest molecules. The understanding of the underlying entropic and enthalpic contributions, and their complex interplay are crucial for the design of new drugs and inhibitors. In this study, molecular dynamics (MD) simulations were performed with inclusion complexes ofα‐cyclodextrin (αCD) and three monosubstituted benzene derivatives to investigate host–guest binding.αCD Complexes are an ideal model system, which is experimentally and computationally well‐known. Thermodynamic integration (TI) simulations were carried out under various conditions for the free ligands in solution and bound toαCD. The two possible orientations of the ligand inside the cavity were investigated. Agreement with experimental data was only found for the more stable orientation, where the substituent resides inside the cavity. The better stability of this conformation results from strongerVan der Waalsinteractions and a favorable antiparallel host–guest dipole–dipole alignment. To estimate the entropic contributions, simulations were performed at three different temperatures (250, 300, and 350 K) and using positional restraints for the host. The system was found to be insensitive to both factors, due to the large and symmetric cavity ofαCD, and the nondirectional nature of the host–guest interactions.
Nucleotides. Part LXXVIII
Authors: Maier Thomas , Pfleiderer Wolfgang
Published: December 2010

Several N(‐hydroxyalkyl)‐2,4‐dinitroanilines were transformed into their phosphoramidites (see 5 and 6 in Scheme 1) in view of their use as fluorescence quenchers, and modified 2‐aminobenzamides (see 9, 10, 18, and 19 in Scheme 1) were applied in model reactions as fluorophors to determine the relative fluorescence quantum yields of the 3′‐Aba and 5′‐Dnp‐3′‐Aba conjugates (Aba=aminobenzamide, Dnp=dinitroaniline). Thymidine was alkylated with N‐(2‐chloroethyl)‐2,4‐dinitroaniline (24) to give 25 which was further modified to the building blocks 27 and 28 (Scheme 3). The 2‐amino group in 29 was transformed by diazotation into the 2‐fluoroinosine derivative 30 used as starting material for several reactions at the pyrimidine nucleus (→31, 33, and 35; Scheme 4). The 3′,5′‐di‐O‐acetyl‐2′‐deoxy‐N2‐[(dimethylamino)methylene]guanosine (37) was alkylated with methyl and ethyl iodide preferentially at N(1) to 43 and 44, and similarly reacted N‐(2‐chloroethyl)‐2,4‐dinitroaniline (24) to 38 and the N‐(2‐iodoethyl)‐N‐methyl analog 50 to 53 (Scheme 5). The 2′‐deoxyguanosine derivative 53 was transformed into 3′,5′‐di‐O‐acetyl‐2‐fluoro‐1‐{2‐[(2,4‐dinitrophenyl)methylamino]ethyl}inosine (54; Scheme 5) which reacted with 2,2′‐[ethane‐1,2‐diylbis(oxy)]bis[ethanamine] to modify the 2‐position with an amino spacer resulting in 56 (Scheme 6). Attachment of the fluorescein moiety 55 at 56 via a urea linkage led to the doubly labeled 2′‐deoxyguanosine derivative 57 (Scheme 6). Dimethoxytritylation to 58 and further reaction to the 3′‐succinate 59 and 3′‐phosphoramidite 60 afforded the common building blocks for the oligonucleotide synthesis (Scheme 6). Similarly, 30 reacted with N‐(2‐aminoethyl)‐2,4‐dinitroaniline (61) thus attaching the quencher at the 2‐position to yield 62 (Scheme 7). The amino spacer was again attached at the same site via a urea bridge to form 64. The labeling of 64 with the fluorescein derivative 55 was straigthforward giving 65. and dimethoxytritylation to 66 and further phosphitylation to 67 followed known procedures (Scheme 7). Several oligo‐2′‐deoxynucleotides containing the doubly labeled 2′‐deoxyguanosines at various positions of the chain were formed in a DNA synthesizer, and their fluorescence properties and the Tms in comparison to their parent duplexes were measured (Tables 1–5).
Towards the Synthesis of 1‐Deoxy‐1‐nitropiperidinoses
Authors: Collin Marie‐Pierre , Vasella Andrea
Published: December 2010

In the course of the first of several attempts to elaborate methods for the synthesis of 1‐nitropiperidinoses, lincosamine was transformed into lactam 6 via hemiacetal 1, lactone 2, amide 3, oxo amide 4, and its cyclic tautomer 5. Treatment of the N‐Boc‐protected lactam oxime 9, obtained from lactam 6, with brominating agents failed to provide the bromonitroso carbamate 10. The N‐Boc‐protected lactam 13 derived from 6 was reduced to hemiacetal 14, but the corresponding N‐Boc‐aminooxime did not tautomerise to the C(1)‐hydroxylamine, and nitrone 17, a potential precursor of the nitropiperidine 12, was not formed. Oxidation of the anomeric azide 20 with HOF⋅MeCN failed to provide the expected nitropiperidine 21. The phosphinimines 22 derived from 20 did not react with O3. In the next approach to 1‐nitropiperidinoses, we treated the N‐Boc‐protected hemiacetal 25, obtained from the known gluconolactam 23 with N‐benzylhydroxylamine. The resulting nitrone 26 exits in equilibrium with the anomeric N‐benzyl‐glycosylhydroxylamine that was oxidized to the anomeric nitrone 28. Ozonolysis of 28 led to the hemiacetal 25, resulting from the desired, highly reactive protected nitropiperidinose 29, that was evidenced by an IR band at 1561 cm−1. Similarly to the synthesis of nitrone 26, reaction of the N‐tosyl‐protected hemiacetal 31 with N‐benzylhydroxylamine and oxidation provided the anomeric N‐benzylhydroxylamines 33 via the p‐toluenesulfonamido nitrone 32. Their oxidation with MnO2 led to the anomeric nitrone 34. Ozonolysis of 34 as evidenced by 1H‐NMR and ReactIR spectroscopy led to the highly reactive nitropiperidinose 35. Like 29, 35 was transformed during workup, and only the hemiacetal 31 was isolated. The similarly prepared lincosamine‐derived nitrone 17 was subjected to ReactIR‐monitored ozonolysis that evidenced the formation of the protected nitropiperidinose 12, but only led to the isolation of 14. The facile transformation of the nitropiperidinoses to hemiacetals is rationalised by heterolysis of the anomeric C,N bond, recombination of the ion pair, and denitrosation of the resulting anomeric nitrite by a nucleophile. Attempts to convert the 1‐deoxy‐1‐nitropiperidinose 35 to uloses 43 by base‐catalysed Michael additions or Henry reactions were unsuccessful.
Two modes of fatty acid binding to bovine β‐lactoglobulin—crystallographic and spectroscopic studies
Authors: Loch Joanna , Polit Agnieszka , Górecki Andrzej , Bonarek Piotr , Kurpiewska Katarzyna , Dziedzicka‐Wasylewska Marta , Lewiński Krzysztof
Published: December 2010

Lactoglobulin is a natural protein present in bovine milk and common component of human diet, known for binding with high affinity wide range of hydrophobic compounds, among them fatty acids 12–20 carbon atoms long. Shorter fatty acids were reported as not binding to β‐lactoglobulin. We used X‐ray crystallography and fluorescence spectroscopy to show that lactoglobulin binds also 8‐ and 10‐carbon caprylic and capric acids, however with lower affinity. The determined apparent association constant for lactoglobulin complex with caprylic acid is 10.8 ± 1.7 × 103 M−1, while for capric acid is 6.0 ± 0.5 × 103 M−1. In crystal structures determined with resolution 1.9 Å the caprylic acid is bound in upper part of central calyx near polar residues located at CD loop, while the capric acid is buried deeper in the calyx bottom and does not interact with polar residues at CD loop. In both structures, water molecule hydrogen‐bonded to carboxyl group of fatty acid is observed. Different location of ligands in the binding site indicates that competition between polar and hydrophobic interactions is an important factor determining position of the ligand in β‐barrel. Copyright © 2010 John Wiley & Sons, Ltd.
Cytogenetic stability of chicken T‐cell line transformed with Marek's disease virus: atomic force microscope, a new tool for investigation
Authors: Di Bucchianico Sebastiano , Giardi Maria Federica , De Marco Patrizia , Ottaviano Luca , Botti Dario
Published: December 2010

The Marek's disease virus (MDV) integration may induce a novel organization of chromatin architecture with a modified genetic expression. In our opinion it is worthwhile trying to relate cytogenetic stability to functional modifications. Recently, atomic force microscopy technique was applied to study the structure of chromosomes at a nanoscale level. This high resolution allows to investigate the different structure of chromatin in order to study cytogenetic stability and chromosome aberrations due to MDV insertion. In this paper data are presented indicating a duplication [78,WZ,dup(1p)(p22–p23)] and a deletion [78,WZ cht del(3)(q2.10)] of Chromosomes 1 and 3 relatively. Relationships between GTG (G‐bands by Trypsin using Giemsa) bands and the topography of chromosomes are also discussed, naming them Topographic Banding. The architecture of chromosomes observed by AFM can be related to the data obtained with classic banding techniques thus overcoming the optical resolution limits. The presence of chromatin bridges between sister chromatids at most of the heterochromatic regions is also evidenced. Besides, we present different studies of the longitudinal and transversal symmetry of the hetero and euchromatic regions to clearly demonstrate a different underlying architecture of these regions. It is indeed evident that the heterochromatic bands are more symmetrical than euchromatic bands. Copyright © 2010 John Wiley & Sons, Ltd.
Insight into molecular imprinting in precipitation polymerization systems using solution NMR and dynamic light scattering
Authors: Long Yuanyuan , Philip Joseph Y. N. , Schillén Karin , Liu Feng , Ye Lei
Published: December 2010

Molecular imprinting is a powerful synthetic technique for generating template‐defined binding sites in cross‐linked polymers. One scientific challenge in molecular imprinting research is to understand the intermolecular interactions leading to molecular complexation and the process of binding site formation during polymerization. In this work, we present a novel method for studying the molecular imprinting process in precipitation polymerization systems. This method employs solution1H NMR and dynamic light scattering (DLS) to investigate the association of template molecules with colloidal particles and the dynamic process of particle growth. Under precipitation polymerization conditions, the colloidal particles formed did not interfere with NMR signals from the soluble components, allowing unreacted monomers and free template to be easily quantified. To examine the process of particle nucleation and growth, DLS was used to measure the hydrodynamic particle size at different reaction times. To corroborate the interpretation of the NMR and DLS results, imprinted nanoparticles were collected at different reaction times and their binding characteristics were evaluated using radioligand‐binding analysis. Our experimental results provide new insights into the molecular imprinting process that will be useful in the development of new imprinted nanoparticles. Copyright © 2010 John Wiley & Sons, Ltd.
Profiles of mature job seekers: Connecting needs and desires to work characteristics
Authors: Nakai Yoshie , Chang Boin , Snell Andrea F. , Fluckinger Chris D.
Published: December 2010

The number of mature job seekers actively pursuing employment is increasing, and it is critical to recognize the variety of needs and desires they want from employment. We hypothesized that mature job seekers would be grouped into meaningful clusters based on their desires for work and that these groups would differ regarding the work features they were looking for in a new job. Using survey data from a sample of 173 mature job seekers over age forty, we identified three clusters: Those who work primarily for monetary and family reasons (which we labeledsatisficers), those who seek personal satisfaction and learning opportunities from employment (free agents), and those who seek employment for a broad variety of reasons (maximizers). These three groups differed in their preferences for work schedule, availability of benefits, and developmental opportunities. We conclude by discussing potential individual‐level interventions and organizational recruitment and staffing strategies for different groups of mature job seekers. Copyright © 2010 John Wiley & Sons, Ltd.
Beyond the red tape: How victims of terrorism perceive and react to organizational responses to their suffering
Authors: Waldman David A. , Carmeli Abraham , Halevi Meyrav Yitzack
Published: December 2010

We use a storyteller perspective to examine how victims of terrorism perceive the way that organizations react and respond to their needs in the aftermath of terrorist attacks. Analysis of the data shows that organizations in Israel are often perceived as ineffective to respond in a humane or compassionate manner to the suffering caused by terrorism. Instead, victims perceive that a more bureaucratic approach is taken. However, to create optimal public value, compassionate responses on the part of organizations in times of trauma, such as terrorist attacks, may be required. We build a theoretical model to show how positive deviance can bring about such responses, as well as positive outcomes for victims. Copyright © 2010 John Wiley & Sons, Ltd.
How and why terrorism corrupts the consistency principle of organizational justice
Authors: Stein Jordan H. , Steinley Douglas , Cropanzano Russell
Published: December 2010

We examined the impact of terrorism on the administration of organizational justice. Based on Terror Management Theory (TMT), it was hypothesized that punishment of deviance would change following an act of terrorism. Specifically, deviant individuals who committed an act high in moral severity would receive more extreme punishment after a terrorist attack than they would have received prior to this incident—thereby compromising consistency in the punishment of deviance, which many organizations seek to maintain. We tested this premise by examining archival punishment data before and after the 9/11 terrorist attacks. The organization we chose was charged with the consistent dispensation of justice and legally constrained in the severity of punishment it could assess—thereby providing a conservative test of our hypotheses. All predictions were supported. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis of Highly Insulated Molecular Wires by Polymerization of Organic‐Soluble Symmetrical Linked Inclusion Complex Monomers
Authors: Terao Jun , Tsuda Susumu , Tsurui Keisuke , Kambe Nobuaki
Published: December 2010

Summary: We developed a new method for synthesizing an organic‐soluble permethylated cyclodextrin‐based insulated molecular wire (IMW); this method involves the polymerization of a symmetrical linked inclusion complex as a monomer. This monomer was synthesized by dimerization of linked inclusion complexes at the terminal alkynyl groups by Glaser coupling. The polyrotaxane thus obtained is highly soluble in a variety of organic solvents and has a high covering ratio, regioregularity, and photoluminescence efficiency.
PVDF Hollow fiber Membrane with High Flux and High Rejection Ratio Prepared by Irradiation Induced Grafting of PAA
Authors: Junfu Wei , Kongyin Zhao , Lei Wang , Huan Zhang , Li Chen , Zhengpu Zhang
Published: December 2010

Summary: A modified poly (vinylidene fluoride) (PVDF) hollow fiber membrane with higher flux and flux recovery rate was prepared by γ‐radiation induced grafting of acrylic acid (AA). The influence of radiation dose and monomer concentration on the grafting degree was investigated. The results indicated that the grafting degree increased in the lower monomer volume fraction until the monomer volume fraction exceeded 20%. The grafting degree increased with the increase of radiation dose. Structural and morphological of the original and grafted membrane surface were characterized by FT‐IR, scanning electron microscopy (SEM). The results indicated that acrylic acid was grafted onto PVDF hollow fiber membrane and the grafted membrane was more hydrophilic than original PVDF. There was a slight increase of breaking strength and yield stress with the increase of the grafting degree of AA. The pure water flux increased initially but decreased subsequently with the raise of grafting degree. When the grafting degree was 4.4%, the maximum pure water flux reached 1496.3 L/m2 × h, 1.79 times of original membrane. The pure water flux, flux recovery rate and rejection ratio for bovine serum albumin could improve simultaneously in a low grafting degree (<4.4%).
Thermosensitive Microparticles Based on Unsaturated Esters of some Poly‐ and Oligosaccharides: Preparation, Characterization, Drug Inclusion and Release
Authors: Hamcerencu Mihaela , Popa Marcel , Desbrieres Jacques , Riess Gerard
Published: December 2010

Summary: The paper concerns the preparation and characterization of hydrogel microparticles based on exopolysaccharide (Gellan, Xanthan) unsaturated derivatives and respectively on cyclodextrin as well as their application for some hydrosoluble and liposoluble drugs inclusion. In the first step the polysaccharide and cyclodextrin unsaturated esters (maleate, acrylate) were synthesized and their hydrogel forming capacity was tested using a grafting‐crosslinking free‐radical reaction with N‐isopropyl acrylamide (NIPAm), at room temperature. For a better control of the crosslinking degree N,N' methylene‐bis‐acrylamide (BIS), replaced by cyclodextrin tri‐acrylate (A‐CD) in a few experiments, was used. The microparticles were obtained by using the method in w/o emulsion, in which the dispersed aqueous phase is the reaction mixture and the oil phase is hexane. The particles containing polysaccharide esters showed an average diameter around 100 µm when crosslinking was achieved with BIS. They were smaller than those crosslinked with A‐CD, which are in the range of 200‐300 µm; the particles based on Xanthan maleate were smaller than Gellan maleate based ones. Even much smaller particles (2‐2.5 µm in diameter) were obtained by starting from A‐CD grafted‐crosslinked systems. The synthesized microparticles are able to include chloramphenicol, as well as progesterone; the drug is slowly released according to diffusion controlled kinetics. The application of these microparticles in emergency ophthalmic treatments is possible as a result of their thermal sensitivity; they can collapse and release the drug instantly when placed in contact with the human eye, at 37 °C.
Electron‐Beam‐Induced Radiation Effects on Siloxane Foam
Authors: Huang Wei , Gao Xiaoling , Xiong Jie , Xiong Liangping , Xu Yunshu , Fu Yibei
Published: December 2010

Summary: Two types of siloxane foam were irradiated by an electron beam at room temperature. Changes in the chemical structure of the samples were determined by Fourier‐transform infrared resonance. The gaseous products from the irradiated samples were analyzed by gas chromatography and mass spectroscopy. Electron spin resonance was used to analyze the free radicals, and the compression properties were determined by a universal material tester. The results indicated that the effect of absorbed dose on the mechanical properties of polymethylvinyl siloxane foam was more pronounced than that for polymethylphenylvinyl siloxane foam. The yield of gases evolved from the radiation degradation of polymethylvinyl siloxane foam was higher than that from polymethylphenylvinyl siloxane foam. The free‐radical signal from polymethylphenylvinyl siloxane foam was stronger and lasted longer than that from polymethylvinyl siloxane foam after irradiation.
The Rebinding Properties of Bovine Serum Albumin Imprinted Calcium Alginate/Phosphate Hybrid Microspheres Via the Adjustment of pH Values and Salt Concentration
Authors: Zhao Kongyin , Cheng Guoxiang , Wei Junfu , Zhou Jinyang , Zhang Jinlong , Chen Li
Published: December 2010

Summary: Bovine serum albumin imprinted calcium phosphate/alginate hydrogel microspheres were prepared with sodium alginate (SA), (NH4)2HPO4, and using CaCl2 as gelling agent, bovine serum albumin (BSA) as template in inverse suspension. The optimized rebinding properties of BSA imprinted hydrogel microspheres were investigated by controlling pH value and ionic concentration from the viewpoint of adjusting the process of gelling, removing template and rebinding. The optimized pH values for the imprinting of BSA in gelling, removing template and rebinding process was 4.1, 8.3 and 4.8, respectively. The effect of NaCl concentration on the BSA rebinding was also determined. We provided a strategy to get the optimized imprinting efficiency by altering pH value and ionic concentration in a weakly ionic cross‐linked hydrogel system on the process of protein's imprinting.
Green as it Gets; Donor‐Acceptor type Polymers as the Key to Realization of RGB Based Polymer Display Devices
Authors: Gunbas Gorkem , Toppare Levent
Published: December 2010

Summary: Polymers that have one of the three complementary colors (red, green, and blue, RGB) in the neutral state and high transmissivity in the oxidized state are the key materials towards use in electrochromic devices and displays. Although many neutral state red and blue polymers have been reported up to date, green polymers with highly transmissive oxidized states, high optical contrasts, fast switching times, and advanced long‐term switching stabilities were essentially missing in the literature. This paper reviews our previous efforts towards realization of neutral state green polymers with highly transmissive oxidized state. The key to this problem was found to be the synthesis of donor‐acceptor polymers bearing benzothiadiazole or quinoxaline derivatives as the acceptor and electron rich 3,4‐ethylenedioxythiophene unit as the donor component. Green neutral state polymeric materials with highly transmissive oxidized state with excellent electrochromic properties have been realized with the design and synthesis of these types of materials. A solution processable green polymeric material has also been realized via chemical polymerization that has shown all superior properties of the electrochemically synthesized counterparts.
Dioxaheteroatom Cyclics as Initiators for Radical Polymerization
Authors: Howell Bob A. , Feng Zeng‐Rui , Cho Young‐Jun
Published: December 2010

Summary: An attractive way to incorporate flame‐retarding moieties into oligomers or polymers is to use strained heterocyclic compounds which contain a thermally‐labile carbon‐carbon bond which will undergo thermolysis at modest temperature to generate a diradical capable of initiating vinyl polymerization. Suitably substituted, they may contain either bromine or phosphorus‐containing moieties, or both. The diol precursors to these heterocycles are generally available from reductive coupling of the corresponding ketones. Conversion of the diols to the heterocycles can be accomplished using standard reagents. Phospholanes generated in this way tend to be quite thermally unstable and often degrade within hours to generate a variety of products. On the other hand, siloles derived from appropriate diols display much greater thermal stability. They can be isolated as crystalline solids and may be used to initiate polymerization at 100‐200 °C. Incorporation of heterocycle‐derived units into the mainchain can impart polymer flame retardancy directly. Alternately, oligomers may be generated for use as flame retardant additives for polymeric materials.
Facilitated temporal summation of pain at spinal level in Parkinson's disease
Authors: Perrotta Armando , Sandrini Giorgio , Serrao Mariano , Buscone Simona , Tassorelli Cristina , Tinazzi Michele , Zangaglia Roberta , Pacchetti Claudio , Bartolo Michelangelo , Pierelli Francesco , Martignoni Emilia
Published: December 2010

Background:

Pain is one of the major nonmotor symptoms of Parkinson's disease. We hypothesized that Parkinson's disease patients could show an early diffuse abnormal processing of the nociceptive inputs also in the absence of clinical pain syndrome and that this could represent the physiopathological substrate to explain the high incidence of diffuse pain symptoms.

Materials and methods:

We used the temporal summation threshold of the nociceptive withdrawal reflex and the related pain sensation to evaluate the facilitation in pain processing at spinal level. Fifteen (7 Women; 8 Men; mean age 63.0 ± 9.1) Parkinson's disease patients without clinical pain and 12 (6 Women, 6 Men; mean age 61.2 ± 4.2) healthy subjects were recruited. Parkinson's disease group has been subdivided into two subgroups, 7 early‐stage Parkinson's disease patients with unilateral signs (Hoehn and Yahr stage 1) and 8 patients in a more advanced stage of the disease showing bilateral parkinsonian signs (Hoehn and Yahr stages 2 and 2.5), both “on” and “off” treatments with levodopa.

Results:

A significant facilitation in temporal summation of pain (reduced temporal summation threshold and increased painful sensation) was found in Parkinson's disease patients when compared with controls. This facilitation is more evident in Parkinson's disease with bilateral signs and on the side more affected in Parkinson's disease with unilateral signs. Levodopa administration failed to significantly modify the neurophysiological abnormalities; however, a slight improvement has been detected.

Conclusions:

The increased gain in pain processing at spinal level in Parkinson's disease patients could be a consequence of the degenerative phenomena involving supraspinal projections implicated in the modulation of pain processing and could make Parkinson's disease patients more predisposed to develop a pain condition. © 2010 Movement Disorder Society
CD36 is involved in lycopene and lutein uptake by adipocytes and adipose tissue cultures
Authors: Moussa Myriam , Gouranton Erwan , Gleize Béatrice , Yazidi Claire El , Niot Isabelle , Besnard Philippe , Borel Patrick , Landrier Jean‐François
Published: December 2010

Scope: Carotenoids are mainly stored in adipose tissue. However, nothing is known regarding the uptake of carotenoids by adipocytes. Thus, our study explored the mechanism by which lycopene and lutein, two major human plasma carotenoids, are transported.

Methods and results: CD36 was a putative candidate for this uptake, 3T3‐L1 cells were treated with sulfosuccinimidyl oleate, a CD36‐specific inhibitor. sulfosuccinimidyl oleate‐treated cells showed a significant decrease in both lycopene and lutein uptake as compared to control cells. Their uptake was also decreased by partial inhibition of CD36 expression using siRNA, whereas the overexpression of CD36 in Cos‐1 cells increased their uptake. Finally, the effect of CD36 on carotenoid uptake was confirmed ex vivo in cultures of adipose tissue explants from CD36−/− mice, which exhibited reduced carotenoid uptake as compared to wild‐type mice explants.

Conclusion: For the first time, we report the involvement of a transporter, CD36, in carotenoid uptake by adipocytes and adipose tissue.
A 6.5–50‐GHz battery‐powered compact rotary joint for polarization ellipticity measurements
Authors: Zürcher J.‐F.
Published: December 2010

A simple, efficient, and compact rotary joint has been designed, realized, and measured.It has been used intensively to perform polarization ellipticity measurements on various circularly polarized antennas (e.g., helical antennas and circularly polarized horns, used either individually or feeding a lens antennas) operating in millimeter‐wave band (∼30 GHz). © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:375–379, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25692
Broadband gap‐coupled assembly of patches forming elliptical patch antenna
Authors: Sharma Vijay , Saxena V. K. , Saini J. S. , Bhatnagar D. , Sharma K. B. , Joshi L. M.
Published: December 2010

The radiation performance of a compact gap‐coupled assembly of patches forming the geometry of elliptical patch antenna is simulated and tested using glass epoxy FR4 substrate material. This assembly is achieved by cutting a conventional elliptical patch antenna geometry into three independent patches through two narrow slits parallel to minor axis of elliptical patch. The two outer patches are identical in shape and size, and the central patch is excited through inset probe feed. Two outer patches are gap coupled to the center patch. This arrangement of antenna elements resonate at three frequencies 3.41, 3.62, and 5.54 GHz, respectively. The first two frequencies are closely spaced and gives an improved bandwidth (>10%). The radiation patterns of antenna at all three frequencies are almost identical in shape and nature. Details of the antenna design approach and experimental results are presented and discussed systematically. Measurements are in excellent agreement with simulation results which make the proposed structure promising for Wi‐Max applications. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:340–344, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25693
High‐frequency low‐power LC divide‐by‐2/3 injection‐locked frequency divider
Authors: Miao Y. N. , Boon C.C. , Do M. A. , Yeo K. S. , Zhang Y. X.
Published: December 2010

An LC divide‐by‐2/3 injection‐locked frequency divider (ILFD) is described, where a pair of switched capacitors is used to select the division ratio between 2 and 3. The locking range analysis of the ILFD based on the gain and phase conditions is discussed. Based on the analysis, the optimized bias current in order to achieve the maximum locking range for the ILFD is obtained and is verified through measurement. The circuit was fabricated in a 0.18 μm CMOS technology. The input frequency of the divide‐by‐2/3 ILFD is from 4.28 to 4.81 GHz with an input power of −0.5 dBm. The power consumption of the ILFD is 3.15 mW at 1.8 V supply voltage. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:337–340, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25694
Dual‐antenna diversity‐gain improvements for even‐odd mode feed network at 755 MHZ
Authors: Kim J. , Kim M. , Jeon S.
Published: December 2010

Improvement in antenna diversity gain due to an even‐odd mode feed network is experimentally estimated at 755 MHz for a closely‐packed dual meander monopole system.The even‐odd mode feed network reduces the mutual coupling between antenna elements from −6 to −16 dB and eliminates the correlation between the radiation patterns. The diversity gain improves from 1.2 to 2.5 dB when the even‐odd mode network replaces the regular separated‐feed network. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:304–306, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25696
Back‐scattering noise reduction using RF tone in RSOA‐based bidirectional optical access link
Authors: Lee Jae‐Min , Won Yong‐Yuk , Han Sang‐Kook
Published: December 2010

The performance of bidirectional optical transmission system using the same wavelength can be easily degraded by Rayleigh backscattering signal.The backscattered signal makes phase noise, and it is detected as intensity noise of baseband in receiver. The unwanted noise interferes with the wanted data signals. The upstream baseband noise can be reduced by frequency chirp induced by RF tone modulation in reflective semiconductor optical amplifier. Verification of the proposed technique has been performed through bidirectional 20‐km transmission experiments at 1.25 Gb/s. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:331–334, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25704
EMFIE and MEFIE formulations for the analysis of scattering from dielectric and composite bodies of revolution
Authors: Resende Úrsula C. , Moreira Fernando J. S. , Pereira‐Filho Odilon M. C.
Published: December 2010

In this article, the electromagnetic scattering from dielectric and composite bodies of revolution are analyzed by the electric‐magnetic field integral equation (EMFIE) and the magnetic‐electric field integral equation (MEFIE), which are customarily overlooked in the literature. A standard method‐of‐moments (MoM) technique is applied for the numerical solution of the surface integral equations. Several dielectric and composite geometries are analyzed through the bandwidth and results are compared with those of well‐established Müller and PMCHWT (a solution proposed by Poggio, Miller, Chang, Harrington, Wu, and Tsai) integral equation formulations. Investigated case studies indicate that the MoM Z‐matrices yielded by the EMFIE and MEFIE are as well‐conditioned as those provided by the Müller and PMCWHT formulations. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:398–402, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25720
High‐gain characteristics of epsilon‐negative first‐order resonator microstrip patch antennas
Authors: Jie X. Y. , Luo C. R. , Liu Y. H. , Tang H. F. , Zhao X. P.
Published: December 2010

A high‐gain microstrip patch antenna based on an epsilon‐negative transmission line is investigated numerically and experimentally. Using the novel resonance of the epsilon‐negative first‐positive‐order resonator, gain of proposed patch antenna could be effectively enhanced. Compared with the conventional patch antenna, the experimental results show that the half‐power beamwidths in the E and H planes of the proposed antenna are both reduced about 16°. As a result, gain of the proposed antenna is enhanced about 2 dB. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:300–303, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25722
Dual‐band antenna design using M‐shaped open stub
Authors: Park Sang Yong , Park Jong Kweon , Kim Jin Suk
Published: December 2010

In this article, we have introduced dual‐band antenna with M‐shaped open stub for wideband local area network (WLAN)/ultra‐wideband (UWB) applications. The M‐shaped open stub is inserted into the proposed antenna for WLAN operation. The proposed antenna is fabricated and measured. Parametric studies and radiation characteristics for the designed antenna was simulated and measured. The designed antenna has the characteristics of wide bandwidth, dual‐band, and negligible dispersion over the UWB band. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:455–458, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25729
TD solution based on UTD‐PO for multiple‐building diffraction with shadowing caused by a wedge‐shaped hill for UWB signals
Authors: Han Tao , Long Yunliang
Published: December 2010

A time domain (TD) solution based on uniform theory of diffraction‐physical optics (UTD‐PO) is presented to analyze the multiple‐building diffraction in urban areas where a wedge‐shaped hill causes shadowing of the transmitter from the receiver.We derive the channel impulse response of the renowned Bertoni's model, which utilizes a recursion relation and does not need to incorporate the slope diffraction in the transition zone. The received signals can be predicted through a simple operation of convolution, which provides a faster and easier final solution for UWB radio propagation and significantly reduces the computational time. The TD result can be applied to analyze the UWB pulse distortion by multiple‐building diffraction in urban areas where the city is surrounded by hilly areas. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:426–429, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25730
A high precision close‐loop programmable CMOS delay generator for UWB and time domain RF applications
Authors: Xu Rui , Nguyen Cam
Published: December 2010

This article presents a novel programmable high precision delay generator with adjustable digital control for ultra‐wideband and time‐domain RF applications.Ring oscillator based phase locked loop (PLL) is embedded to achieve desired propagation delay in the delay cell against process, temperature, and power supply variations. A replica inverter delay line parallel to the PLL offers a separate delay path for input clock. Sub‐nanosecond delay step with high accuracy can be obtained by shaping the input clock slope and keeping a careful matching between the replica delay line and the delay cell in PLL. The prototype of the delay generator is implemented on a 0.18‐μm CMOS process. The measurement results show relative delay error of 0.8%. The circuit consumes 9.5 mA from a 1.8‐V power supply. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:390–392, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25732
A fast domain decomposition method based on orthogonal polynomials approximation for solving electromagnetic scattering problems
Authors: Lü Zhi‐Qing , An Xiang
Published: December 2010

The partial basic solution vector based domain decomposition method (PBSV‐DDM) is well suited for solving large‐scale finite periodic electromagnetic problems.In this work, a new implementation scheme is developed to improve the efficiency of the PBSV‐DDM. A set of orthogonal polynomials is introduced to approximate the transmission condition between adjacent subdomains, which results in solving for the polynomial coefficients instead of the dual unknowns. The major advantages of the proposed method are: (i) the computational cost and the memory requirement for the PBSV matrix are decreased significantly; (ii) the computational efforts of the matrix‐vector multiplication during iterations can also be reduced greatly; (iii) in contrast with the rank‐revealing matrix factorization based DDM, this method does not need to explicitly produce the entire PBSV matrix in advance. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:357–361, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25734
Experimental investigation of resonant frequency of multilayered rectangular and circular microstrip antennas
Authors: Kumar Raj , Malathi P.
Published: December 2010

This article presents the experimental results and verification of design expressions of multilayer rectangular and circular microstrip patch. Three rectangular and circular microstrip patch of different dimension have been fabricated on substrates εr2 = 4.3, thickness 1.53 mm and εr2 = 2.2, thickness 0.787 mm. The measurements have been carried out for simple microstrip patch, covered microstrip patch, space dielectric patch and microtrip patch with two superstrate. The experimental results obtained have been compared with reported design expression of multilayer rectangular and circular Microstrip patch in (Kumar and Malathi, Microwave Opt Technol Lett (2007), 2946‐2950; Microwave Opt Technol Lett 40 (2008), 3206‐3212). The experimental resonant frequency is in close agreement with the calculated resonant frequency. Such experimental validation and results may prove to be more useful for design engineers and further investigation. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:352–356, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25735