bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of dipyrone in pharmaceutical preparations based on the chemiluminescent reaction of the quinolinic hydrazide–H2O2–vanadium(IV) system and flow‐injection analysis
Authors: Pradana Pérez Juan A. , Durand Alegría Jesús S. , Hernando Pilar Fernández , Sierra Adolfo Narros
Published: June 2011

A rapid, economic and sensitive chemiluminescent method involving flow‐injection analysis was developed for the determination of dipyrone in pharmaceutical preparations. The method is based on the chemiluminescent reaction between quinolinic hydrazide and hydrogen peroxide in a strongly alkaline medium, in which vanadium(IV) acts as a catalyst. Principal chemical and physical variables involved in the flow‐injection system were optimized using a modified simplex method. The variations in the quantum yield observed when dipyrone was present in the reaction medium were used to determine the concentration of this compound. The proposed method requires no preconcentration steps and reliably quantifies dipyrone over the linear range 1–50 µg/mL. In addition, a sample throughput of 85 samples/h is possible. Copyright © 2011 John Wiley & Sons, Ltd.
Use of an automated capillary DNA sequencer to investigate the interaction of cisplatin with telomeric DNA sequences
Authors: Paul Moumita , Murray Vincent
Published: June 2011

The determination of the sequence selectivity of DNA‐damaging agents is very important in elucidating the mechanism of action of anti‐tumour drugs. The development of automated capillary DNA sequencers with fluorescent labelling has enabled a more precise method for DNA sequence specificity analysis. In this work we utilized the ABI 3730 capillary sequencer with laser‐induced fluorescence to examine the sequence selectivity of cisplatin with purified DNA sequences. The use of this automated machine enabled a higher degree of precision of both position and intensity of cisplatin–DNA adducts than previously possible with manual and automated slab gel procedures. A problem with artefact bands was overcome by ethanol precipitation. It was found that cisplatin strongly formed adducts with telomeric DNA sequences. Copyright © 2011 John Wiley & Sons, Ltd.
Scale‐up of mouse embryonic stem cell expansion in stirred bioreactors
Authors: Fernandes‐Platzgummer Ana , Diogo Maria M. , Baptista Ricardo P. , Silva Cláudia Lobato da , Cabral Joaquim M.S.
Published: June 2011

The aim of this study was to develop a robust, quality controlled and reproducible large‐scale culture system using serum‐free (SF) medium to obtain vast numbers of embryonic stem (ES) cells as a starting source for potential applications in tissue regeneration, as well as for drug screening studies. Mouse ES (mES) cells were firstly cultured on microcarriers in spinner flasks to investigate the effect of different parameters such as the agitation rate and the feeding regimen. Cells were successfully expanded at agitation rates up to 60 rpm using the SF medium and no significant differences in terms of growth kinetics or metabolic profiles were found between the two feeding regimens evaluated: 50% medium renewal every 24 h or 25% every 12 h. Overall, cells reached maximum concentrations of (4.2 ± 0.4) and (5.6 ± 0.8) ×106 cells/mL at Day 8 for cells fed once or twice per day; which corresponds to an increase in total cell number of 85 ± 7 and 108 ± 16, respectively. To have a more precise control over culture conditions and to yield a higher number of cells, the scale‐up of the spinner flask culture system was successfully accomplished by using a fully controlled stirred tank bioreactor. In this case, the concentration of mES cells cultured on microcarriers increased 85 ± 15‐fold over 11 days. Importantly, mES cells expanded under stirred conditions, in both spinner flask and fully controlled stirred tank bioreactor, using SF medium, retained the expression of pluripotency markers such as Oct‐4, Nanog, and SSEA‐1 and their differentiation potential into cells of the three embryonic germ layers. © 2011 American Institute of Chemical Engineers Biotechnol. Prog.,, 2011
Click‐Dendronized Poly(amide–triazole)s—Effect of Dendron Size and Polymer Backbone Symmetry on Self‐Assembling and Gelation Properties
Authors: Chow Hak‐Fun , Lau Kwun‐Ngai , Chan Man‐Chor
Published: June 2011

Nine dendronized poly(amide–triazole)s 2‐Gm Gn (m=1–3, n=1–3), were prepared by the 1:1 copolymerization between AA‐type dendritic diazides 4‐Gm (m=1–3) and BB‐type dendritic diacetylenes 5‐Gn (n=1–3) under the copper(I)‐mediated click coupling conditions. The degree of polymerization value of the polymers was found to range from 15–50, and decreased with increasing size of the dendron, suggesting steric hindrance had a retardation role on the copolymerization efficiency. Based on FT‐IR and 1H NMR studies, it was found that significantly strong, interchain hydrogen bonding between the amide units was present in the solution state after copolymerization, whereas the monomers 4‐Gm and 5‐Gn were devoid of any intermolecular hydrogen‐bonding interaction. Hence a positive allosteric hydrogen‐bonding effect was observed after polymerization, and could be rationalized by the zip effect. The strength of the interchain association in polymers 2‐Gm Gn was found to decrease with increasing size of the dendron (i.e., 2‐G1 G1>2‐G1 G2>2‐G2 G1≈2‐G2 G2>2‐G1 G3≈2‐G3 G1>2‐G2 G3≈2‐G3 G2>2‐G3 G3). Among the nine polymers, only 2‐G1 G2 and 2‐G2 G1 were good organogelators for aromatic solvents, while the 2‐G2 G2 polymer, bearing the closest structural resemblance to the previously reported organogelator 1‐G2 prepared from the polymerization of AB‐type monomers, was devoid of gelating power. Careful analysis of structures of the present polymer series 2‐Gm Gn and the previously reported series 1‐Gn suggested that the polymer backbone symmetry played a subtle role in controlling their self‐assembling and gelating properties.
ChemInform Abstract: Artificial Selenoenzymes: Designed and Redesigned
Authors: Huang Xin , Liu Xiaoman , Luo Quan , Liu Junqiu , Shen Jiacong
Published: June 2011

Review: ca. 80 refs.
Retraction: Evaluation of Co‐Digestion at a Commercial Dairy Anaerobic Digester
Authors: Frear Craig , Liao Wei , Ewing Tim , Chen Shulin
Published: June 2011

The above article published online on 16 June 2011 in Wiley Online Library (http://www.onlinelibrary.wiley.com), and in Volume 39, pp. 697‐704, has been retracted by agreement between the Editor‐in‐Chief, Prisca Henheik, and Wiley‐VCH Verlag GmbH & Co. KgaA.

The retraction has been agreed following an investigation carried out by Washington State University (WSU) which determined that research misconduct had occurred with respect to fabricating experimental data and falsifying data that formed the basis of a section of this article on the part of the corresponding author. Furthermore, WSU determined that the corresponding author did not declare an existing commercial conflict of interest when submitting the paper to the peer‐‐reviewed journal CLEAN ‐ Soil, Air, Water.
Cytomorphologic features of advanced lung adenocarcinomas tested for EGFR and KRAS mutations: A retrospective review of 50 cases
Authors: Marotti Jonathan D. , Schwab Mary C. , McNulty Nancy J. , Rigas James R. , DeLong Peter A. , Memoli Vincent A. , Tsongalis Gregory J. , Padmanabhan Vijayalakshmi
Published: June 2011

Associations between bronchioloalveolar carcinoma (BAC), mucinous differentiation, and epidermal growth factor receptor (EGFR) and KRAS mutations have been previously reported in studies of surgical specimens. We present the cytomorphology of lung adenocarcinomas, including metastases that were diagnosed by cytologic methods and the relationship to both EGFR and KRAS mutational status. We retrospectively reviewed the clinical and cytomorphologic features of 50 lung adenocarcinomas that were tested for both EGFR and KRAS mutations. Cytomorphologic features evaluated included cell size, architectural pattern, nucleoli, intranuclear cytoplasmic inclusions (INCI), mucin, necrosis, squamoid features, lymphocytic response, and histologic features of BAC differentiation. DNA was extracted from a paraffin‐embedded cell block or frozen needle core fragments. Exon 19 deletions and the L858R mutation in exon 21 of EGFR were detected using PCR followed by capillary electrophoresis for fragment sizing. KRAS mutational analysis was performed by real‐time PCR using a set of seven different Taqman(r) allelic discrimination assays to detect six mutations in codon 12 and one mutation in codon 13. Six cases (12%) showed EGFR mutations, 12 (24%) showed KRAS mutations, and 38 (62%) contained neither EGFR nor KRAS mutations. The majority of patients had stage IV disease (78%); 20 samples (40%) were from metastatic sites. The presence of prominent INCI (P = 0.036), papillary fragments (P = 0.041), and histologic features of BAC on paraffin block (P = 0.039) correlated with the presence of EGFR mutations. The presence of necrosis (P = 0.030), squamoid features (P = 0.048), and poorly differentiated tumors (P = 0.025) were more likely to be identified in the KRAS positive group. Diagn. Cytopathol. 2013. © 2011 Wiley Periodicals, Inc.
Early oogenesis in the short‐tailed fruit bat Carollia perspicillata: Transient germ cell cysts and noncanonical intercellular bridges
Authors: Lechowska Agnieszka , Bilinski Szczepan M. , Rasweiler John J. , Cretekos Chris J. , Behringer Richard R. , Kloc Malgorzata
Published: June 2011

The ovaries of early embryos (40 days post coitum/p.c.) of the bat Carollia perspicillata contain numerous germ‐line cysts, which are composed of 10 to 12 sister germ cells (cystocytes). Variability in the number of cystocytes within the cyst and between the cysts (defying the Giardina rule) indicates that the mitotic divisions of the cystoblast are asynchronous in this bat species. Serial section analysis showed that the cystocytes are interconnected via intercellular bridges that are atypical, strongly elongated, short‐lived, and rich in microtubule bundles and microfilaments. During slightly later stages of embryonic development (44–46 days p.c.), somatic cells penetrate the cyst, and their cytoplasmic projections separate individual oocytes. Separated oocytes surrounded by a single layer of somatic cells constitute the primordial ovarian follicles. The oocytes of C. perspicillata are similar to mouse oocytes and are asymmetric. In both species, this asymmetry is clearly recognizable in the localization of the Golgi complexes. The presence of germ‐line cysts and intercellular bridges (although noncanonical) in the fetal ovaries of C. perspicillata suggest that the formation of germ‐line cysts is an evolutionarily conserved phase in the development of the female gametes in a substantial part of the animal kingdom. Genesis 50:18‐27, 2012. © 2011 Wiley Periodicals, Inc.
Oxygen‐Deficient R2MoO6–δ (R = Tb, Dy, Y, Ho, Er, Tm, Yb) with Fluorite Structure as Potential Anodes in Solid Oxide Fuel Cells
Authors: Aguadero A. , Martínez‐Lope M. J. , Pomjakushin V. , Alonso J. A.
Published: June 2011

The members of the family of oxygen‐defective fluorites R2MoO6–δ (R = Tb, Dy, Y, Ho, Er, Tm, Yb) have been synthesized under reducing conditions and characterized in order to evaluate their potential use as anodes in intermediate‐temperature solid oxide fuel cells (IT‐SOFCs). A neutron powder diffraction (NPD) investigation demonstrates that they are all cubic, in the Fm$\bar {3}$m space group, exhibiting a random distribution of R and Mo cations over the metal sites of the fluorite structure with crystallographic formulaMO2–δ/3 (M = R2/3Mo1/3), Z = 4. These materials are highly oxygen‐deficient fluorites with oxygen stoichiometries ranging from 5.2(1) (R = Y, Tm) to 4.8(1) (R = Tb, Dy, Ho, and Er) oxygen atoms per formula unit, accompanied by high values of the displacement parameters at room temperature (ca. 5 Å2), which suggests a high mobility of the oxygen atoms. An in situ NPD study of the thermal evolution of the crystal structure for Ho2MoO6–δ confirms the absence of phase transitions and a high oxygen‐vacancy concentration and mobility [B(O) = 6.7(1) Å2] in the network under the usual working conditions of an anode in a SOFC (PO2 ≈ 10–6 Torr, 500–700 °C). The thermal expansion coefficients of the sintered samples exhibit values around 9 × 10–6 K–1 from 300 to 900 °C under 5 % H2/95 %N2, which perfectly match the thermal expansions of the other components of a SOFC. The maximum conductivity values are displayed for the fluorite containing Tb, ranging from 0.03 (200 °C) to 1.1 (900 °C) S cm–1 with an activation energy of 0.31 eV.
Stereoselective Synthesis of 2H‐Chromans by Reductive Deoxygenation of Differently Substituted 2‐Sulfinylmethylchroman‐2‐ols
Authors: Hernández‐Torres Gloria , Carreño M. Carmen , Urbano Antonio , Colobert Françoise
Published: June 2011

Good‐to‐excellent diastereoselectivies have been achieved in the synthesis of 2H‐chromans by Et3SiH/TMSOTf reductive deoxygenation of differently substituted 2‐sulfinylmethylchroman‐2‐ols and their methyl ketals. The influence of both electron‐donating and ‐withdrawing substituents on the sulfoxide and on the aromatic dihydobenzopyran core has been studied. SOR1 electron‐donating groups (R1 = pMeOPh and 2‐MeO‐1‐naphthyl) led to a competitive reaction in which the sulfoxide was reduced, thus lowering the yield of the sulfinyl 2H‐chromans. The method allows the presence of different groups on the aromatic dihydrobenzopyran unit. The best results in terms of yield and diastereoselectivity were obtained with 2‐[(p‐tolylsulfinyl)methyl]chroman‐2‐ols. All the results are explained on mechanistic grounds. Synthetic transformations of the enantiopure 2H‐chroman (S,RS)‐21 are reported.
Biocatalyzed Enantioselective Reduction of Activated C=C Bonds: Synthesis of Enantiomerically Enriched α‐Halo‐β‐arylpropionic Acids
Authors: Brenna Elisabetta , Gatti Francesco G. , Manfredi Alessia , Monti Daniela , Parmeggiani Fabio
Published: June 2011

The enantioselective biocatalyzed reduction of the C=C bond of some (Z)‐methyl α‐halo‐β‐arylacrylates was investigated. The reaction was performed by baker's yeast fermentation and Old Yellow Enzymes 1–3 mediated biotransformations. The final products were, respectively, enantiomerically enriched (S)‐α‐halo‐β‐arylpropionic acids and their methyl esters, and ester hydrolysis was promoted in the whole cell system. High conversions and enantioselectivity values were observed when the aromatic ring was substituted by an electron‐withdrawing group. Further manipulation of two of these enantiomerically enriched (S)‐haloacids afforded p‐substituted D‐phenylalanines.
De Novo Synthesis of Racemic 4‐Deoxy‐4,4‐difluoro‐ and 2,4‐Dideoxy‐2,4,4‐trifluorohexosides
Authors: Giuffredi Guy T. , Bernet Bruno , Gouverneur Véronique
Published: June 2011

A range of racemic 4‐deoxy‐4,4‐difluorinated carbohydrates were prepared by using a diversity‐oriented de novo synthesis starting with three commercially available two‐carbon building blocks. A common gem‐difluorinated glycal was prepared in 35 % yield in seven steps, from which five different 4‐deoxy‐4,4‐difluoro‐ and 4‐deoxy‐2,4,4‐trifluorohexopyranosides were accessed using well‐established functional group manipulations.
Enhanced extraction of 3‐demethylated colchicine from fermentation broth of Bacillus megaterium: Optimization of process parameters by statistical experimental design
Authors: Dubey Kashyap K. , Jawed Arshad , Haque Shafiul
Published: June 2011

Biotransformation of colchicine into its pharmacologically active regiospecific derivative 3‐demethylated colchicine (3‐DMC) mediated by microbial monooxygenases is an economic and promising strategy for the production of this inexpensive and potent anti‐cancer drug. Response surface methodology (RSM), with central composite design (CCD) model, was employed with three extraction variables (temperature, pH, and process time) for optimization; which most significantly affected recovery of 3‐DMC. The validity of the model was ascertained by running the predicted values in an individual run; and the optimum parameters, temperature (50°C), pH (10), and process time (120 min) resulted in a maximum recovery of 3‐DMC 4128 mg/L when chloroform (1% v/v) was used as an extraction solvent. RSM in our experiments showed to be a good tool for the extraction of 3‐DMC from the fermentation medium.
Role of prophylactic thyroidectomy in RET 790 familial medullary thyroid carcinoma
Authors: Bihan Hélène , Baudin Eric , Meas Taly , Leboulleux Sophie , Al Ghuzlan Abir , Hannoteaux Véronique , Travagli Jean‐Paul , Valleur Patrice , Guillausseau Pierre‐Jean , Cohen Régis ,   for the French Group of Endocrine Tumors (GTE)
Published: June 2011

Background

We describe a family harboring RET 790 mutation and review the role of prophylactic thyroidectomy for medullary thyroid carcinoma.

Methods

We evaluated in detail both clinical and biological follow‐up and reviewed literature reports.

Results

Among 86 family members, 15 of 22 members screened harbored the 790 mutation. Abnormal calcitonin levels were found in 8/15. Total thyroidectomy with lymph node dissection cured the 5 operated patients (range, 45–76 years). Tumor staging was pT1N0M0. Among 10 carriers who did not undergo surgery, 3 patients had abnormal calcitonin levels. For the others, calcitonin levels remained <30 pg/mL. Two asymptomatic carriers were older than 70 years. Four subjects were lost to follow‐up.

Conclusions

In RET codon 790 mutations families, a case‐by‐case decision instead of systematic prophylactic thyroidectomy should be discussed. Difficulties of follow‐up should be taken into account and represent the main challenge. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Predictors of relapse in a study of duloxetine treatment for patients with generalized anxiety disorder
Authors: Bodkin J. Alexander , Allgulander Christer , Llorca Pierre M. , Spann Melissa E. , Walker Daniel J. , Russell James M. , Ball Susan G.
Published: June 2011

Objective

Data from a relapse prevention study of duloxetine treatment for adults with generalized anxiety disorder (GAD) were examined to identify predictors of relapse.

Methods

Patients responding to 6 months of open‐label duloxetine treatment were randomized to continuation with duloxetine or withdrawal to placebo for a 6‐month double‐blind continuation phase (duloxetine, N = 216; placebo, N = 213). Post hoc analyses compared time to GAD relapse during continuation phase by using predictor variables that included patient demographics, symptom severity measures (Hamilton Anxiety Scale Scores [HAMA], Hospital Anxiety and Depression Scale), functional outcomes, and visual analogue scale (VAS) pain measures. Univariate and multivariate analyses were performed using predictor variables from time of randomization into the continuation, withdrawal phase.

Results

Severity of anxiety symptoms, degree of functional impairment, and severity of pain at time of randomization were significantly predictive of likelihood of relapse during the continuation phase. Multivariate backwards elimination analysis of significant univariate predictors identified HAMA item one (anxious mood) ≥1 and severity of pain while awake (≥30 on VAS) as the strongest predictors of GAD relapse.

Conclusions

For patients with GAD responding to open‐label treatment with duloxetine, residual symptoms related to anxious mood, pain severity, and psychosocial function were associated with increased relapse risk, although the greatest risk was associated with anxious mood and increased severity of pain while awake. Copyright © 2011 John Wiley & Sons, Ltd.
Smad6 is essential to limit BMP signaling during cartilage development
Authors: Estrada Kristine D , Retting Kelsey N , Chin Alana M , Lyons Karen M
Published: June 2011

Bone morphogenetic protein (BMP) signaling pathways regulate multiple aspects of endochondral bone formation. The importance of extracellular antagonists as regulators of BMP signaling has been defined. In vitro studies reveal that the intracellular regulators, inhibitory Smads 6 and 7, can regulate BMP-mediated effects on chondrocytes. Although in vivo studies in which inhibitory Smads were overexpressed in cartilage have shown that inhibitory Smads have the potential to limit BMP signaling in vivo, the physiological relevance of inhibitory Smad activity in skeletal tissues is unknown. In this study, we have determined the role of Smad6 in endochondral bone formation. Loss of Smad6 in mice leads to defects in both axial and appendicular skeletal development. Specifically, Smad6−/− mice exhibit a posterior transformation of the seventh cervical vertebra, bilateral ossification centers in lumbar vertebrae, and bifid sternebrae due to incomplete sternal band fusion. Histological analysis of appendicular bones revealed delayed onset of hypertrophic differentiation and mineralization at midgestation in Smad6−/− mice. By late gestation, however, an expanded hypertrophic zone, associated with an increased pool of proliferating cells undergoing hypertrophy, was evident in Smad6 mutant growth plates. The mutant phenotype is attributed, at least in part, to increased BMP responsiveness in Smad6-deficient chondrocytes. Overall, our results show that Smad6 is required to limit BMP signaling during endochondral bone formation. © 2011 American Society for Bone and Mineral Research
Proteolysis of the matricellular protein hevin by matrix metalloproteinase‐3 produces a SPARC‐like fragment (SLF) associated with neovasculature in a murine glioma model
Authors: Weaver Matt , Workman Gail , Schultz Chad R. , Lemke Nancy , Rempel Sandra A. , Sage E. Helene
Published: June 2011

The matricellular SPARC‐family member hevin (Sparc‐like 1/SPARCL‐1/SC1/Mast9) contributes to neural development and alters tumor progression in a range of mammalian models. Based on sequence similarity, we hypothesized that proteolytic digestion of hevin would result in SPARC‐like fragments (SLF) that affect the activity and/or location of these proteins. Incubation of hevin with matrix metalloproteinase‐3 (MMP‐3), a protease known to cleave SPARC, produced a limited number of peptides. Sequencing revealed the major proteolytic products to be SPARC‐like in primary structure. In gliomas implanted into murine brain, a SLF was associated with SPARC in the neovasculature but not with hevin, the latter prominent in the astrocytes encompassed by infiltrating tumor. In this model of invasive glioma that involves MMP‐3 activity, host‐derived SLF was not observed in the extracellular matrix adjacent to tumor cells. In contrast, it occurred with its homolog SPARC in the angiogenic response to the tumor. We conclude that MMP‐3‐derived SLF is a marker of neovessels in glioma, where it could influence the activity of SPARC. J. Cell. Biochem. 112: 3093–3102, 2011. © 2011 Wiley Periodicals, Inc.
Studies on coupled biological and photochemical treatment of soda pulp bleaching effluents from agro residue based pulp and paper mill
Authors: Dhir Amit , Prakash Nagaraja Tejo , Sud Dhiraj
Published: June 2011

BACKGROUND:The effect of coupled biological and photochemical processes for treatment of bio‐recalcitrant effluents from chlorination (C) and first alkaline extraction (E1) stages of soda pulp bleaching in an agro‐residue based pulp and paper mill has been investigated.

RESULTS:The work aims to evaluate the coupled effect on the extent of degradation in terms of chemical oxygen demand (COD) reduction. Biological treatment of C and E1effluent resulted in 30% and 57% COD, respectively, after 1 day of treatment with acclimatized activated sludge. However, further increase in retention time did not show any significant change in degradation efficiency. Investigations on photocatalytic treatment (at 365 nm and 0.625 W) of C effluent resulted in 47% degradation under optimized conditions (3 g L−1TiO2, pH 6.0 and 0.01 mol L−1NaOCl), and E1effluent showed 37% degradation under optimized conditions (2.5 g L−1, pH 4.0 and 0.03 mol L−1NaOCl) after 6 h of UV irradiation. However, photocatalytic treatment of biotreated (1 day) effluents under similar optimized conditions significantly enhanced the degradation to 81% and 93% in C and E1effluent, respectively, after 2 h irradiation.

CONCLUSION:Coupled biological treatment followed by photocatalysis is an effective method for the reduction of total organic carbon (TOC) of the test effluents and it would facilitate closed circuiting of water used for soda bleaching in an agro pulp and paper mill. Copyright © 2011 Society of Chemical Industry
Degradation of β‐carotene in amorphous polymer matrices. Effect of water sorption properties and physical state
Authors: Ramoneda Ximena A , Ponce‐Cevallos Peggy A , Buera María del Pilar , Elizalde Beatriz E
Published: June 2011

BACKGROUND: The use of encapsulation in amorphous matrices of carbohydrate and/or polymer formed during dehydration processes to enhance the stability and retention of labile compounds is increasing in the food and pharmaceutical industries. Efforts to improve encapsulating properties have been made using mixtures of carbohydrates with proteins or gums in different proportions. The objective of the present work was to study the stability of encapsulated β‐carotene and its degradation kinetics in maltodextrin/gum arabic and maltodextrin/gelatin matrices in relation to the physical properties and state of the dehydrated matrix.

RESULTS: The degradation of β‐carotene followed a first‐order kinetic model of fractional retention for all encapsulating matrices. The Guggenheim–Anderson–de Boer (GAB) model was adequate to describe the sorption isotherms of the studied systems. β‐Carotene losses were observed mainly at relative humidities (RHs) above the glass transition temperatures (Tg) of the corresponding systems, where the matrices were fully plasticised and collapsed (75 and 92% RH). At these high RHs the best β‐carotene retention was obtained in the system containing gum arabic.

CONCLUSION: The results showed that pigment degradation was determined by the physical state of the matrix, related to the degree of collapse. They represent a contribution to the knowledge of physical factors that affect the retention kinetics of labile biomolecules encapsulated in dehydrated matrices. Copyright © 2011 Society of Chemical Industry
Modifying glucose release from high carbohydrate foods with natural polymers extracted from cereals
Authors: Razzaq Hussam AA , Sutton Kevin H , Motoi Lidia
Published: June 2011

BACKGROUND: Sustained elevated blood glucose and insulin levels are linked to many health problems that may be prevented or better managed by controlling glucose availability for uptake. Glucose release from consumed starch may be altered by the processing conditions, particle size and structural features of the food, and by the addition of dietary fibres. Many approaches to lower glucose release are not suitable for all high carbohydrate foods, especially bakery products. Methods to modulate the starch digestion without compromising product quality are required. This study describes an approach to protect the granules and alter the particle size of the starch component using an extract from barley (BE). Wheat starch was suspended in the BE at different ratios and cast dried, milled to 2–3 mm particles, or finely ground to produce different particle sizes.

RESULTS: The BE treatments resulted in the formation of clusters of starch granules embedded in a matrix of fibres and protein. The rate of in vitro starch digestion was decreased, and further reduction occurred when the particle size of the starch material increased.

CONCLUSION: The extract provided a physical barrier that limited the starch exposure to the digestion enzymes and water that led to reduction in starch digestion and the release of glucose Copyright © 2011 Society of Chemical Industry
Synthesis of Collagenase‐Sensitive Polyureas for Ligament Tissue Engineering
Authors: Benhardt Hugh , Sears Nick , Touchet Tyler , Cosgriff‐Hernandez Elizabeth
Published: June 2011

Recently, poly(ester urethanes) were investigated for use as ligament grafts due to their exceptional mechanical properties and highly tunable structure; however, these grafts are susceptible to hydrolytic degradation that occurs independent of tissue regeneration. To address this limitation, polyureas containing collagen‐derived peptides were synthesized which enable cellular release of proteases to dictate degradation rate. It is hypothesized that this cell‐responsive design will facilitate load transfer from the biodegradable scaffold to neotissue at a rate that promotes proper tissue orientation and function while maintaining construct integrity.

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Poly(D,L‐Lactide)‐block‐Poly(2‐Hydroxyethyl Acrylate) Block Copolymers as Potential Biomaterials for Peripheral Nerve Repair: in vitro and in vivo Degradation Studies
Authors: Clément Benoît , Decherchi Patrick , Féron François , Bertin Denis , Gigmes Didier , Trimaille Thomas , Marqueste Tanguy
Published: June 2011

The properties of poly(D,L‐lactide)‐block‐poly(2‐hydroxyethyl acrylate) (PLA‐b‐PHEA) block copolymers by means of in vitro / in vivo (rat) degradation are investigated and compared to those of PLA homopolymer. Over 12 weeks, we observe mass loss and molecular weight decrease. In vitro and in vivo findings are very similar for each polymer tested. When a short PHEA block is used (PLA‐b‐PHEA 15 000–3 000 g · mol−1, 85/15 wt%), the degradation process is found to be very similar to that of homo‐PLA, and to be typical of a bulk erosion mechanism, with no mass loss observed until week 7 and continuous decrease of molar mass within this timeframe. For a longer PHEA block length within the block copolymer (PLA‐b‐PHEA 15 000–7 500 g · mol−1, 65/35 wt%), the degradation mechanism is modified, with a significant mass loss observed at early times and only a slight decrease in molar mass. The latter finding is related to the pronounced hydrophilicity and softness of the material induced by the PHEA block, which allow easy diffusion and rapid leakage of the degradation residues from the material towards the aqueous medium. Schwann cells are found to better adhere on spin‐coated films of PLA‐b‐PHEA (85/15 wt%) than on PLA ones. These results show the potential of such hydrophilized PLA‐based copolymers for use in peripheral nerve repair.

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Enthalpy and Volume Relaxation of Core‐Crosslinked Star Polystyrene/Poly(methyl methacrylate) Blends
Authors: Spoljaric Steven , Genovese Antonietta , Goh Tor Kit , Blencowe Anton , Qiao Greg G. , Shanks Robert A.
Published: June 2011

Blends of linear and core‐crosslinked star (CCS) polymers are prepared. The relaxation and thermal properties of the blends are determined using conventional and modulated‐temperature DSC and modulated‐temperature thermomechanometry. Addition of CCS polymers increase the glass transition temperature while decreasing the enthalpy and the linear coefficient of thermal expansion, suggesting that the hyperbranched polymers restrict matrix chain motions. Isothermal annealing increased the Tg and ΔH and decreased sub‐Tg α due to the reduced free volume and mobility within the polymer films. Volume relaxation during annealing is observed using mT‐TM, while a stretched‐exponential function is utilised to interpret the data.

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Square‐integrable solutions and Weyl functions for singular canonical systems
Authors: Behrndt Jussi , Hassi Seppo , de Snoo Henk , Wietsma Rudi
Published: June 2011

Boundary value problems for singular canonical systems of differential equations of the form

are studied in the associated Hilbert space \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$L^2_\Delta (\imath )$\end{document}. With the help of a monotonicity principle for matrix functions their square‐integrable solutions are specified. This yields a direct treatment of defect numbers of the minimal relation and simultaneously makes it possible to assign certain boundary values to the elements of the maximal relation induced by the system of differential equations in \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$L^2_\Delta (\imath )$\end{document}. The investigation of boundary value problems for these systems and their spectral theory can be carried out by means of abstract boundary triplet techniques. This paper makes explicit the construction and the properties of boundary triplets and Weyl functions for singular canonical systems. Furthermore, the Weyl functions are shown to have a property similar to that of the classical Titchmarsh‐Weyl coefficients for singular Sturm‐Liouville operators: they single out the square‐integrable solutions of the homogeneous systems of canonical differential equations. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Transcriptional down‐regulation of Brca1 and E‐cadherin by CtBP1 in breast cancer
Authors: Deng Yu , Deng Hui , Liu Jing , Han Gangwen , Malkoski Stephen , Liu Bolin , Zhao Rui , Wang Xiao‐Jing , Zhang Qinghong
Published: June 2011

Carboxyl‐terminal binding protein 1 (CtBP1) is a transcriptional co‐repressor with oncogenic potential. Immunohistochemistry staining using human breast cancer tissue arrays revealed that 92% of invasive ductal breast cancer cases have CtBP1‐positive staining compared to 4% CtBP1‐positive in normal breast tissue. To explore the functional impact of CtBP1 in breast cancer, we examined CtBP1's transcriptional regulation of known tumor suppressors, breast cancer susceptibility gene 1 (Brca1), and E‐cadherin. We found CtBP1 was recruited to the promoter regions of Brca1 and E‐cadherin genes in breast cancer cells. Concomitantly, Brca1 loss was detected in 57% and E‐cadherin loss was detected in 76% of human invasive ductal breast cancers, and correlated with CtBP1 nuclear staining in these lesions. Importantly, siRNA knock down of CtBP1 restored Brca1 and E‐cadherin expression in breast cancer cell lines, implying CtBP1 down‐regulates Brca1 and E‐cadherin genes in human breast cancer. This study provides evidence that although genetic loss of Brca1 and E‐cadherin are infrequent in breast cancer, they are down‐regulated at the transcriptional level by CtBP1 expression. Thus, CtBP1 activation could be a potential biomarker for breast cancer development. © 2011 Wiley Periodicals, Inc.
Investigation of ionic conductivity in track‐etched nanoporous polyimide membranes using a microwave technique
Authors: Molenberg I. , Planckaert M. , Jonckheere L. , Ferain E. , Huynen I.
Published: June 2011

The in situ characterization of membranes for fuel cell applications is a rather complex and time‐consuming procedure. It is therefore interesting to develop simple, short, and reproducible characterization tests and to limit in situ measurement only to the most promising materials. In this paper, a new characterization method is proposed to extract the DC ionic conductivity of track‐etched nanoporous polyimide membranes from microwave measurements. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26163
Compact monopole antenna with triple band‐notched characteristics for UWB applications
Authors: Zhao Jin‐Juan , Ren Li‐Shi , Gong Shu‐Xi , Xu Yun‐Xue
Published: June 2011

A novel compact ultrawideband (UWB) antenna with triple band‐notched characteristics is proposed. Triple narrow band‐notched characteristics are achieved by embedding a spade‐shaped slot on the radiating patch as well as adding a separated strip on the front side and a bowl‐shaped resonator on the backed plane of the reference UWB antenna. The measured impedance bandwidth defined by voltage standing wave ratio (VSWR) < 2 of 8.0 GHz (3.0–11.0 GHz), with the triple notched bands of 3.3–3.7, 5.15–5.4, and 5.7–5.9 GHz, are obtained. The proposed antenna with an overall dimension of only 24 mm × 29 mm is successfully designed and measured, showing broadband matched impedance and stable radiation patterns. Moreover, measured group delay and transmission characteristics indicate that the proposed antenna has good transient response. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26167
A novel design of 3‐dB coupler with harmonics suppression using Powell's least square method
Authors: Li Rui , Kim Dong Il , Wu Duo‐Long , Yang Qiang
Published: June 2011

This article presents a simplified design of a compact structure with harmonics suppression. The suggested structure is based on a conventional 3‐dB branch line coupler, and two pairs of open stubs are adopted at the λ/4 branches to suppress harmonics. With this configuration, two finite attenuation poles will be available, which are able to suppress the second and third harmonics simultaneously. A model of transmission line is introduced for tuning the finite attenuation poles, and the optimal condition could be achieved by using Powell's least square method. To assess the effectiveness of the proposed structure, a novel 3‐dB coupler with harmonics suppression is designed, fabricated, and measured. The numerical results demonstrate an excellent match between the numerical analysis and actual measurements. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26171
Analysis of the effect of high‐dielectric substrate size on the directivity of an end‐fire antenna
Authors: Eldek Abdelnasser A. , El‐Hefnawi Fatma
Published: June 2011

Analysis of the effect of the substrate size of the end‐fire double rhombus antenna on its directivity is performed. The purpose is to increase the directivity without increasing antenna width for this antenna to be used in a circular array node as part of a cell phone detection system for post‐disaster search and rescue operations. It was found that the directivity of the antenna can be increased by increasing the length of the dielectric substrate. Different configurations have been studied to obtain high directivity. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26173
Efficient SP‐FDTD algorithm for solving oblique incident plane wave in dispersive materials
Authors: Wang Hui , Huang Zhi‐xiang , Wu Xian‐liang
Published: June 2011

In this letter, an efficient method of introducing plane wave source into finite difference time domain (FDTD) grids, denoted as the method of splitting plane wave FDTD algorithm, is presented for solving oblique incident wave in dispersive material.The details of new equations for one‐dimensional propagators based on spitted‐field of Maxwell's equations are also provided and practical implementations are also included. Numerical examples are presented that demonstrate the valid of the method and reduce a minimal amount of the field leakage error below −300 dB. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26174
Simulation of an operation of zinc oxide light‐emitting diodes
Authors: Kowalczewski Piotr , Kuc Maciej , Piskorski Łukasz , Sarzała Robert P. , Nakwaski Wlodzimierz
Published: June 2011

The self‐consistent thermal–electrical model of the ZnO light‐emitting diode is presented. It may be used to determine the band structure of the diode, its quasi‐Fermi levels and two‐dimensional profiles of temperature, potential, carrier concentrations, and current densities. The model may also enable its structure optimization for various possible applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26175
Design of an internal FM radio antenna for mobile handsets with an arrow‐shaped patch
Authors: Choi Sunho , Kim Gi‐Ho , Seong Won‐Mo , Kwak Kyung‐Sup
Published: June 2011

This article describes the design, fabrication, and measurement of an internal FM radio ferrite sheet flexible antenna using an arrow‐shaped patch to enhance passive gain performance for mobile handsets.To obtain sufficient passive gain performance ≥–20 dBi, an arrow‐shaped patch is inserted in the antenna radiator and monopole type wire is used. The measured result of the fabricated antenna provides passive gain performance (15.6–13.5 dBi) from 86 to 108 MHz with the frequency modulation (FM) bandwidth from 83.20 to 123.72 MHz (≤voltage standing wave ratio (VSWR) 6:1). Also, a good radiation pattern is achieved within the FM bandwidth (86–108 MHz) range. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26180
Design of RF subsystem for dynamic spectrum sharing system in UHF band
Authors: You Changjiang , Zhu Xiaowei , Liu Jing , Zhang Xiaodong , Chen Jia , Cao Zhigang
Published: June 2011

A radio frequency (RF) subsystem used in ultra‐high frequency (UHF) band dynamic spectrum sharing wireless communication system is presented.It is composed of three data RF transceivers and one cognitive RF receiver. Every RF transceiver consists of transmitting chain and receiving chain, and the receiving chain is designed the same as cognitive RF receiver. The measured error vector magnitude (EVM) of transmitting chain is less than 1.5%, when the output signal power is 30 dBm. The measured IMD3 of transmitting chain is less than −50 dBc, when the input signal is two tones with 10 kHz space, and the output signal power is 30 dBm. The measured EVM of cognitive RF receiver and receiving chain is less than 1.0% when the input signal power is −50 dBm. The measured lowest noise figure of cognitive RF receiver and receiving chain is 3.41 dB, and it shows agreement with the analysis result. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26181
Differential six‐port demodulator
Authors: Owais Owais , Östh Joakim , Serban Adriana , Karlsson Magnus , Gong Shaofang
Published: June 2011

A differential six‐port demodulator for the 7–8 GHz band is reported for the first time. It is composed of a differential six‐port correlator on the two sides of the substrate and zero‐bias antiparallel Schottky diodes acting as power detectors. It is theoretically analyzed and also simulated. A prototype has been fabricated and data transmission at 0.8 Gbit/s (but not the maximum) with the 16 quadrature amplitude modulation (QAM) is experimentally demonstrated. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26191
Notched half‐circled planar monopole antenna for ultra‐wide band application
Authors: Thakur Jay Prakash , Kim Won‐Gyum , Kim Yong‐Hoon
Published: June 2011

This article presents the planar ultra‐wide band (UWB) monopole antenna design and its impedance bandwidth improvement.Intially, a planar rectangualr monopole antenna is designed for UWB application. To enhance the impedance bandwidth of the antenna, the planar structure is modified by including a half circle at the right side edge of the rectangular patch and further notched at the other edge. Hence, the three planar monopole antenna designs are introduced namely, rectangular, rectangular plus half circle, and finally rectangular half circled including notch. The finally designed notch‐circled planar antenna has the capability of operating between 3.8 and 10.2 GHz compared to conventionally designed rectangular antenna that performs between 4.6 and 9.9 GHz. It shows about 1 GHz impedance bandwidth improvement. The simulations of the all three antennas have been performed using EM simulators, CST and HFSS. Further, the simulated antenna return losses are compared with the measurements. Also the E‐ and H‐plane radiation patterns of the antenna are measured for the frequencies of 3.9, 6.3, and 10.2 GHz. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26194
Improving the radiation performance of the Sierpinski microstrip fractal patch antenna through novel feed methods
Authors: Church Justin , Sharma Satish K.
Published: June 2011

This article investigates the effect of introducing novel feed methods such as the three‐port and a single‐port corporate feed in the Sierpinski microstrip fractal patch antenna for achieving enhanced radiation performance. It will be shown that by exciting the antenna with these feed methods generates more uniform current distributions across the frequency band (8–18 GHz) than the same antenna fed‐in using the single port, conventional feed mechanism. This leads to enhanced radiation pattern performance including the realized gain. A prototype antenna was fabricated and experimentally verified for both impedance matching and radiation patterns. The simulation and measured results are in reasonable agreement. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26195
Small‐size wideband chip antenna for WWAN/LTE operation and close integration with nearby conducting elements in the mobile handset
Authors: Chen Shu‐Chuan , Wong Kin‐Lu
Published: June 2011

A wideband chip antenna having a small size of 3 × 15 × 35 mm3 for application in the mobile handset to cover eight‐band WWAN/LTE operation is presented. The antenna is mainly formed by a direct‐feed two‐branch strip and a coupled‐fed shorted strip. The two‐branch strip functions as an efficient radiator and also as a coupling feed to capacitively excite the shorted strip. The coupled‐fed shorted strip contributes a wide resonant mode at about 800 MHz to cover the LTE700/GSM850/900 (704∼ 960 MHz) operation. The two‐branch strip and the shorted strip together contribute their fundamental or higher‐order resonant modes to cover the GSM1800/1900/UMTS/LTE2300/2500 (1710∼ 2690 MHz) operation. There are also ground planes located on two side surfaces of the chip antenna, which are grounded to the system ground plane printed on the main circuit board of the mobile handset. This configuration allows the antenna to be closely integrated with nearby conducting or electronic elements such as a universal series bus connector to achieve compact integration of the internal antenna in the mobile handset. Details of the proposed antenna are presented. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26200
Characterization of material anisotropy using microwave ellipsometry
Authors: Gambou F. , Bayard B. , Noyel G.
Published: June 2011

The aim of this article is to propose an original low‐cost new experimental technique for the characterization of anisotropic media.This technique is based on free‐space transmission ellipsometry at microwave frequency (30 GHz). This method allows to obtain the electromagnetic anisotropy in a material through the measurement of microwave polarization states. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26201
A compact coupled radiator antenna with reduced hand effect for mobile handset applications
Authors: Jung Kang‐Jae , Won Jung Chang , Park Myun‐Joo , Chung Young‐Seek , Kim Deokyun , Kim Byeongkwan , Wi Hyunho , Kim Taekyun , Lee Byungje
Published: June 2011

A wideband/multiband antenna with compact coupled radiators is proposed for reduction of the hand effect in mobile phone applications.The impedance bandwidth of the proposed antenna can be twice the bandwidth of a conventional PIFA, so that the measured average gain under the influence of the hand phantom is higher than that of a conventional PIFA over the entire GSM850/EGMS900 bands. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26202