bluuebunny/crossref_metadata_2025 huggingface dataset:
Microanatomy of the paired‐fin pads of ostariophysan fishes (Teleostei: Ostariophysi)
Authors: Conway Kevin W. , Lujan Nathan K. , Lundberg John G. , Mayden, Richard L. , Siegel Dustin S.
Published: July 2012

Members of the teleost superorder Ostariophysi dominate freshwater habitats on all continents except Antarctica and Australia. Obligate benthic and rheophilic taxa from four different orders of the Ostariophysi (Gonorynchiformes, Cypriniformes, Characiformes, and Siluriformes) frequently exhibit thickened pads of skin along the ventral surface of the anteriormost ray or rays of horizontally orientated paired (pectoral and pelvic) fins. Such paired‐fin pads, though convergent, are externally homogenous across ostariophysan groups (particularly nonsiluriform taxa) and have been considered previously to be the result of epidermal modification. Histological examination of the pectoral and/or pelvic fins of 44 species of ostariophysans (including members of the Gonorynchiforms, Cypriniformes, Characiformes, and Siluriformes) revealed a tremendous and previously unrecognized diversity in the cellular arrangement of the skin layers (epidermis and subdermis) contributing to the paired‐fin pads. Three types of paired‐fin pads (Types 1–3) are identified in nonsiluriform ostariophysan fishes, based on differences in the cellular arrangement of the epidermis and subdermis. The paired‐fin pads of siluriforms may or may not exhibit a deep series of ridges and grooves across the surface. Two distinct patterns of unculus producing cells are identified in the epidermis of the paired‐fin pads of siluriforms, one of which is characterized by distinct bands of keratinization throughout the epidermis and is described inAmphilius platychir(Amphiliidae) for the first time. General histological comparisons between the paired fins of benthic and rheophilic ostariophysan and nonostariophysan percomorph fishes are provided, and the possible function(s) of the paired‐fin pads of ostariophysan fish are discussed. J. Morphol. 2012. © 2012 Wiley Periodicals, Inc.
Dimerization in the Grb7 Protein
Authors: Peterson Tabitha A. , Benallie Renee L. , Bradford Andrew M. , Pias Sally C. , Yazzie Jaron , Lor Siamee N. , Haulsee Zachary M. , Park Chad K. , Johnson Dennis L. , Rohrschneider Larry R. , Spuches Anne , Lyons Barbara A.
Published: July 2012

In previous studies, we showed that the tyrosine phosphorylation state of growth factor receptor–bound protein 7 (Grb7) affects its ability to bind to the transcription regulator FHL2 and the cortactin‐interacting protein, human HS‐1‐associated protein‐1. Here, we present results describing the importance of dimerization in the Grb7–Src homology 2 (SH2) domain in terms of its structural integrity and the ability to bind phosphorylated tyrosine peptide ligands. A tyrosine phosphorylation‐mimic mutant (Y80E–Grb7–SH2) is largely dimerization deficient and binds a tyrosine‐phosphorylated peptide representative of the receptor tyrosine kinase (RTK) erbB2 with differing thermodynamic characteristics than the wild‐type SH2 domain. Another dimerization‐deficient mutant (F99R–Grb7–SH2) binds the phosphorylated erbB2 peptide with similarly changed thermodynamic characteristics. Both Y80E–Grb7–SH2 and F99R–Grb7–SH2 are structured by circular dichroism measurements but show reduced thermal stability relative to the wild type–Grb7–SH2 domain as measured by circular dichroism and nuclear magnetic resonance. It is well known that the dimerization state of RTKs (as binding partners to adaptor proteins such as Grb7) plays an important role in their regulation. Here, we propose the phosphorylation state of Grb7–SH2 domain tyrosine residues could control Grb7 dimerization, and dimerization may be an important regulatory step in Grb7 binding to RTKs such as erbB2. In this manner, additional dimerization‐dependent regulation could occur downstream of the membrane‐bound kinase in RTK‐mediated signaling pathways. Copyright © 2012 John Wiley & Sons, Ltd.
Fluorescence correlation spectroscopy study of protein transport and dynamic interactions with clustered‐charge peptide adsorbents
Authors: Daniels Charlisa R. , Kisley Lydia , Kim Hannah , Chen Wen‐Hsiang , Poongavanam Mohan‐Vivekanandan , Reznik Carmen , Kourentzi Katerina , Willson Richard C. , Landes Christy F.
Published: July 2012

Ion‐exchange chromatography relies on electrostatic interactions between the adsorbent and the adsorbate and is used extensively in protein purification. Conventional ion‐exchange chromatography uses ligands that are singly charged and randomly dispersed over the adsorbent, creating a heterogeneous distribution of potential adsorption sites. Clustered‐charge ion exchangers exhibit higher affinity, capacity, and selectivity than their dispersed‐charge counterparts of the same total charge density. In the present work, we monitored the transport behavior of an anionic protein near clustered‐charge adsorbent surfaces using fluorescence correlation spectroscopy. We can resolve protein‐free diffusion, hindered diffusion, and association with bare glass, agarose‐coated, and agarose‐clustered peptide surfaces, demonstrating that this method can be used to understand and ultimately optimize clustered‐charge adsorbent and other surface interactions at the molecular scale. Copyright © 2012 John Wiley & Sons, Ltd.
Phytochemicals in fruits of two Prunus domestica L. plum cultivars during ripening
Authors: Usenik Valentina , Stampar Franci , Kastelec Damijana
Published: July 2012

BACKGROUND: Plums are a rich source of nutritive and bioactive compounds. The objective was to evaluate the impact of fruit tissue (flesh and peel), ripening stage and cultivar on the composition of phytochemicals in plums (Prunus domestica L.) and to analyse the relation between total antioxidant activity (TAA) and the measured variables.

RESULTS: The content of total sugars and total organic acids was higher in flesh but total phenolic content (TPC) and TAA was statistically higher in plum peel. The composition of sugars depended on fruit tissue, ripening stage and the cultivar. Ripening and fruit tissue affected the composition and concentrations of organic acids. TPC of ‘Haganta’ peel increased during ripening but there was no significant time trend for ‘Jojo’ peel and flesh of both cultivars. The composition of phenolics in peel depended on the cultivar, but in flesh on the cultivar and ripening. Ripening resulted in increased total anthocyanins and TAA in peel. TAApeel was positively correlated with TPCpeel, total anthocyaninspeel, cyanidin 3‐glucosidepeel and peonidin 3‐rutinosidepeel in the cultivar ‘Haganta’.

CONCLUSION: The composition of phytochemicals in P. domestica fruit depends on fruit tissue, ripening stage and the cultivar. Peel contributes to the TAA on average 20 times more than flesh. © 2012 Society of Chemical Industry
Potential application of superparamagnetic nanoparticles for extraction of bacterial genomic DNA from contaminated food and environmental samples
Authors: Basu Semanti , Chatterjee Saptarshi , Bandyopadhyay Arghya , Sarkar Keka
Published: July 2012

BACKGROUND: Isolation of high‐molecular‐weight DNA is essential for many molecular biology applications. Owing to the presence of polymerase chain reaction (PCR) inhibitors, there is a scarcity of suitable protocols for PCR‐ready DNA extraction from food and natural environments. The conventional chemical methods of DNA extraction are time consuming and laborious and the yield is very low. Thus the aim of this research was to develop a simple, rapid, cost‐effective method of genomic DNA extraction from food (milk and fruit juice) and environmental (pond water) samples and to detect bacterial contaminants present in those samples.

RESULTS: This approach is efficient for both Gram‐positive and Gram‐negative bacteria from all the studied samples. Herein super paramagnetic bare iron oxide nanoparticles were implemented for bacterial genomic DNA isolation. The method was also compared to the conventional phenol–chloroform method in the context of quality, quantity and timing process. This method took only half an hour or less to obtain high‐molecular‐weight purified DNA from minimum bacterial contamination. Additionally, the method was directly compatible to PCR amplification.

CONCLUSION: The problem of availability of suitable generalized methods for DNA isolation from various samples including food and environmental has been solved by a nanobiotechnological approach that may prove to be extremely useful in biotechnological applications. © 2012 Society of Chemical Industry
Bone tumor reconstruction with the Ilizarov method
Authors: McCoy Thomas H. , Kim Han Jo , Cross Michael B. , Fragomen Austin T. , Healey John H. , Athanasian Edward A. , Rozbruch S. Robert
Published: July 2012

Background and Objectives

Patients with musculoskeletal tumors can face large bone deficiency, deformity, and nonunion. Distraction osteogenesis via the Ilizarov method may be useful for reconstruction of these deficiencies allowing limb preservation and optimizing function.

Methods

We reviewed 20 patients with a range of musculoskeletal tumors necessitating surgical treatment. The group included 9 females and 11 males with a mean age of 22.6 (8–58) years at a mean follow up of 81.7 (26–131) months. The mean bone deficiency was 7.9 (1.2–18.0) cm.

Results

The mean lengthening achieved was 7.1 (3.5–18.0) cm over an EFI of 33.5 (range, 9.5–58.3) days/cm. This treatment resulted in 10 excellent and 3 good ASAMI bone scores, 10 excellent and 3 good ASAMI function scores, a mean lower extremity MSTS score of 93% and a mean upper extremity MSTS score of 87%. Treatment resulted in 2 complications, 18 obstacles, and 6 problems.

Conclusion

The Ilizarov method is an effective technique for limb reconstruction of bone tumors, although extended time in external fixation is required. Since no one in this group received simultaneous chemotherapy or radiotherapy, we cannot comment on use of the Ilizarov method with these treatments. Further use and clinical follow‐up is warranted. J. Surg. Oncol. 2013;107:343–352. © 2012 Wiley Periodicals, Inc.
Surgical management of rectal gastrointestinal stromal tumors
Authors: Tielen Ronald , Verhoef Cornelis , van Coevorden Frits , Reyners Anna K. , van der Graaf Winette T.A. , Bonenkamp Johannes J. , van Etten Boudewijn , de Wilt Johannes H.W.
Published: July 2012

Background

Five percent of gastrointestinal stromal tumors (GISTs) are primarily localized in the rectum. We analyzed the outcome of multimodality treatment for rectal GIST in a multicenter retrospective series.

Methods

All surgically treated patients with a rectal GIST were identified from four specialized centers in the Netherlands. Primary endpoints were disease‐free survival (DFS) and overall survival (OS).

Results

Thirty‐two patients (22 men and 10 women) with rectal GISTs were identified. Twenty‐two patients received imatinib before surgery for a median of 9 (range 2–53) months (Group 1). Ten patients received no imatinib because of small tumor size or lack of availability (Group 2). Median tumor size before treatment was 9.3 (range 6–17) cm in Group 1 and median 6 (range 4–14) cm in Group 2. A complete resection was possible in 17/22 (77%) patients in Group 1 versus 7/10 (70%) in Group 2. Median DFS was not reached in Group 1, while it was 36 months in Group 2. Median OS was not reached in both groups.

Conclusions

Preoperative imatinib leads to downsizing of the tumors in Group 1. However, it has not led to less extensive surgery. The DFS is longer in patients treated with pre‐ and post‐operative imatinib, without an effect on OS. J. Surg. Oncol. 2013;107:320–323. © 2012 Wiley Periodicals, Inc.
Comprehensive characterization of Stevia Rebaudiana using two‐dimensional reversed‐phase liquid chromatography/hydrophilic interaction liquid chromatography
Authors: Fu Qing , Guo Zhimou , Zhang Xiuli , Liu Yanfang , Liang Xinmiao
Published: July 2012

Two‐dimensional reversed‐phase liquid chromatography/hydrophilic interaction liquid chromatography (2D‐RPLC/HILIC) system was successfully applied for comprehensive characterization of steviol glycosides from Stevia rebaudiana. The experiments were performed in offline mode using an XCharge C18 column in first dimension and an XAmide column in second dimension. In first dimension, preliminary separation of Stevia aqueous extract was accomplished and 30 fractions were collected. Then fractions 1–20 were selected for further purification and 13 compounds with high purity were obtained in second dimension. Comprehensive characterization of these compounds was completed by determination of their retention time, accurate molecular weight, diagnostic fragmentation ions, and nuclear magnetic resonance spectroscopy. As a result, all nine known steviol glycosides, as well as other four steviol glycosides were fully purified. The result demonstrated that this procedure is an effective approach for the preparative separation and comprehensive characterization of steviol glycosides in Stevia. This 2D‐RPLC/HILIC method will be a promising tool for the purification of low‐abundance compounds from natural products.
Columns and optimum gradient conditions for fast second‐dimension separations in comprehensive two‐dimensional liquid chromatography
Authors: Hájek Tomáš , Jandera Pavel
Published: July 2012

Gradient elution provides significantly higher peak capacity in comparison to the isocratic elution mode, hence it is very useful in online comprehensive two‐dimensional liquid chromatography (LC). We compared suitability of five commercial core‐shell columns and one monolithic column for fast gradients in the second LC dimension, where the time of separation is strictly limited by the fraction cycle time. In two‐dimensional reversed‐phase systems with partially correlated retention, the resolution, the peak capacity, and the regularity of coverage of the second‐dimension retention space can be improved by appropriate adjusting the gradient time and the gradient range to suit the sample properties. We developed a new strategy for adjusting the gradient mobile phase composition range in the second‐dimension, employing the retention data of representative sample standards characterizing the sample properties, which can be calibrated using the reference alkylbenzene series. Optimized second‐dimension gradients with single‐step or segmented profiles covering two or more fraction ranges, employed for the separation of subsequent fractions from the first‐dimension, improve significantly the resolution, the separation time, and the regularity of coverage of the two‐dimensional retention plane. The approach was applied to the two‐dimensional comprehensive separation of phenolic acids and flavonoid compounds occurring as natural antioxidants.
Theories to support method development in comprehensive two‐dimensional liquid chromatography – A review
Authors: Bedani Filippo , Schoenmakers Peter J. , Janssen Hans‐Gerd
Published: July 2012

On‐line comprehensive two‐dimensional liquid chromatography techniques promise to resolve samples that current one‐dimensional liquid chromatography methods cannot adequately deal with. To make full use of the potential of two‐dimensional liquid chromatography, optimization is required. Optimization of two‐dimensional liquid chromatography is a relatively new yet important research topic the aim of which is to predict combinations of stationary and mobile phases, column formats, and chromatographic conditions that maximize resolving power and minimize analysis time. In on‐line two‐dimensional liquid chromatography, dilution‐related issues play also an important role and these should be taken into account when developing optimization strategies. In this work, state‐of‐the‐art strategies that support method development for on‐line two‐dimensional liquid chromatography through a rigorous choice of chromatographic parameters are critically reviewed. The final aim is to provide practitioners with a clear understanding of which aspects can be optimized using current on‐line two‐dimensional liquid chromatography strategies (and which ones cannot). In two‐dimensional liquid chromatography, maximizing resolving power for a given analysis time and dilution requires optimizing efficiency, selectivity and retention. While great strides forward have been made in the optimization of efficiency‐related issues, considerable effort needs still to be made in terms of (1) developing models that can predict the retention factors that given stationary/mobile phase systems can provide and (2) using this information for choosing the two ones that maximize two‐dimensional liquid chromatography orthogonality. Because of this limitation, in two‐dimensional liquid chromatography, this aspect is typically dealt with a posteriori through examining chromatograms. This review clearly shows that important progress in the optimization of on‐line two‐dimensional liquid chromatography has recently been made.
Isolation of fucoxanthin from edible brown algae by microwave‐assisted extraction coupled with high‐speed countercurrent chromatography
Authors: Xiao Xiaohua , Si Xiaoxi , Yuan Zhiquan , Xu Xianfang , Li Gongke
Published: July 2012

A rapid and efficient method for the separation and purification of fucoxanthin from edible brown algae by microwave‐assisted extraction coupled with high‐speed countercurrent chromatography was developed. The algae were first extracted using microwave‐assisted extraction, then the dried extract was dissolved and directly introduced into the high‐speed countercurrent chromatography system with a two‐phase solvent system consisting of hexane‐ethyl acetate‐ethanol‐water (5:5:6:4, v/v/v/v). The isolation was done in less than 75 min, and a total of 0.83 mg, 1.09 mg, and 0.20 mg fucoxanthin were obtained from 25.0 g fresh Laminaria japonica Aresch, 1.5 g dry Undaria pinnatifida (Harv) Sur, and 15.0 g dry Sargassum fusiforme (Harv) Setch, respectively. The purity of fucoxanthin determined by HPLC was over 90% and its structure was further identified by LC‐ESI‐MS and 1H‐NMR.
Quantitative determination of aceclofenac and its three major metabolites in rat plasma by HPLC‐MS/MS
Authors: Kim Eunyoung , Ahn Byoungki , Noh Keumhan , Kang Wonku , Gwak Hye sun
Published: July 2012

We developed a method for the simultaneous quantification of aceclofenac and its three major metabolites in rat plasma. After protein precipitation with acetonitrile including flufenamic acid as an internal standard (IS), aceclofenac, diclofenac, 4′‐hydroxyaceclofenac, 4′‐hydroxydiclofenac, and the IS were chromatographed on a reverse‐phase C18 analytical column. The isocratic mobile phase of acetonitrile/0.1% formic acid (aq; 9:1 [v/v]) was eluted at 0.3 mL/min. Quantification was performed on a triple‐quadrupole mass spectrometer using electrospray ionization, and the ion transitions were monitored in selective reaction‐monitoring mode. The coefficient of variation in the assay precision was less than 8%, and the accuracy was 92–103%. This method was successfully used to measure the concentrations of aceclofenac and its three major metabolites in rat plasma following the oral administration of a single 20 mg/kg oral dose of aceclofenac.
Bayesian uncertainty quantification of recent shock tube determinations of the rate coefficient of reaction H + O2→ OH + O
Authors: Miki Kenji , Cheung Sai Hung , Prudencio Ernesto E. , Varghese Philip L.
Published: July 2012

We analyze the ignition delay in hydrogen–oxygen combustion and the important chain ‐branching reaction H + O2→ OH + O that occurs behind the shock waves in shock tube experiments. We apply a stochastic Bayesian approach to quantify uncertainties in the theoretical model and experimental data. The approach involves a statistical inverse problem, which has four “components” as input information: (a) model, (b) prior joint probability density function (PDF) of the uncertain parameters, (c) experimental data, and (d) uncertainties in the scenario parameters. The solution of this statistical inverse problem is a posterior joint PDF of the uncertain parameters from which we can easily extract statistical information. We first perform a parametric study to investigate how the level of the total uncertainty (which we define as the sum of model uncertainty and experimental uncertainty) affects the uncertainty in the rate coefficient k1 of the reaction H + O2→ OH + O, which is “most likely” expressed by k1=1.73×1023T−2.5exp(−11550/T) cm3 mol−1 s−1 over the experimental temperature range 1100–1472 K. We also introduce the idea of “irreducible” uncertainty when considering other parameters in the system. After statistically calibrating the parameters modeling the rate coefficient k1, we predict its 95% confidence interval (CI) for different temperature regimes and compare the CI against the values of k1 obtained deterministically. Our results show that a small uncertainty in gas temperature (±5 K) introduces appreciable uncertainty in k1. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 586–597, 2012
Functional Poly(Dimethyl Aminoethyl Methacrylate) by Combination of Radical Ring‐Opening Polymerization and Click Chemistry for Biomedical Applications
Authors: Maji Samarendra , Mitschang Fabian , Chen Lina , Jin Qiao , Wang Youxiang , Agarwal Seema
Published: July 2012

In this work, the macromolecular design and modular synthesis of degradable and biocompatible copolymers via radical polymerization and click chemistry is highlighted and the resulting systems are evaluated as gene delivery carriers. Poly(ethylene glycol) (PEG) grafted poly[2‐methylene‐1,3‐dioxepane (MDO)‐co‐propargyl acrylate (PA)‐co‐2‐(dimethyl aminoethyl methacrylate (DMAEMA)] (MPD) is synthesized using radical polymerization and azide‐alkyne click chemistry. The polymers are less cytotoxic and are able to condense plasmid DNA into nanosized particles. The low transfection efficiency of polyplexes in HepG2 cells is significantly improved by mixing Tat peptide with polyplexes.
On the Nature of the Breath Figures Self‐Assembly in Evaporated Polymer Solutions: Revisiting Physical Factors Governing the Patterning
Authors: Bormashenko Edward , Balter Sagi , Aurbach Doron
Published: July 2012

The breath‐figures self‐assembly process was studied. Polystyrene and polycarbonate were dissolved in a diversity of solvents including, acetone, dichloromethane, chloroform, carbon tetrachloride, tetrahydrofuran, toluene, xylenes, carbon disulfide, and N‐N dimethylformamide, and then were evaporated in a humid atmosphere. It was demonstrated that all solutions when sufficiently pre‐cooled gave rise to typical “breath‐figures” patterns. Thus, the decisive factor affecting the formation of the breath‐figures pattern is the temperature of the solution. Wetting properties of the manufactured patterns are reported.
Structure and Properties of Cellulose Films Reinforced by Chitin Whiskers
Authors: Huang Yao , Zhang Lina , Yang Juan , Zhang Xianzheng , Xu Min
Published: July 2012

Cytocompatible nanocomposite films are prepared by blending α‐chitin whiskers and cellulose solution in NaOH/urea. Structure and properties of the chitin/cellulose composite films are characterized by FT‐IR, XRD, 13C NMR, SEM, UV‐Vis, TGA, and tensile tests. The results reveal that the chitin whiskers are dispersed homogeneously, leading to good miscibility and properties of the chitin/cellulose composite films. By varying the chitin whisker content, the tensile strength and elastic modulus of the films can be controlled. HeLa and T293 cells are seeded onto the surfaces of the nanocomposite films, showing that the composite films were nontoxic to both cell types and that the addition of chitin whiskers promotes cell adhesion and proliferation.

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Verification of Selected Key Assumptions for the Analysis of Depth‐Sensing Indentation Data
Authors: Rettler Erik , Kranenburg Johannes M. , Hoeppener Stephanie , Hoogenboom Richard , Schubert Ulrich S.
Published: July 2012

Methods for indentation analysis involve assumptions that may be problematic for visco‐elastic materials. Three assumptions are discussed: (1) the unloading is predominantly elastic, (2) tip/sample adhesion and friction are negligible, and (3) no cracking occurs around the indent. A series of copolymers is investigated by indentation at room temperature, just below their glass transitions. Closer to the glass transition assumptions (1) and (2) were violated. Erroneous analysis due to extensive creep was identified by comparison of the creep rate at the end of the hold period with the unloading displacement rate and from the power of the fit to the unloading response. Assumption (3) was studied by scanning the indenter tip over the residual indent in polystyrene, which is known to be susceptible to stress localization.

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Strategies for the Synthesis of Poly(2‐Oxazoline)‐Based Hydrogels
Authors: Kelly Andrew M. , Wiesbrock Frank
Published: July 2012

Poly(2‐oxazoline)‐based networks currently receive great interest due to their versatile properties that can be tailor made by desktop‐planned modifications. This feature summarizes strategies for the preparation of these networks, comprising the in situ cross‐linking as well as polymer‐analogous cross‐linking routines such as (reversible) complex formation, physical processes, and covalent bond formation (involving reactions with olefinic species as well as with epoxides, isocyanates, aldehydes, acids, and their derivatives). Reflecting prominent application examples in the biomedic(in)al sector, poly(2‐oxazoline)‐co‐polyester networks are described in a dedicated section.
Evaluation of the Electrophilicites and Band Gaps of Conductive Polymers: A New Model
Authors: Noorizadeh Siamak , Shakerzadeh Ehsan
Published: July 2012

It is shown that the obtained hardness and electrophilicity values of the short length oligomers for a heterocyclic conductive polymer from density functional theory method are quadraticly correlated to those obtained from semiempirical method. Therefore these quantities for all oligomers (up to 15 repeating units) are predicted using the obtained quadratic relations. Both of these predicted quantities for different oligomers are fitted to a new exponential model (Y = Y∞ ed/n) to estimate the electronic properties for the considered conjugated polymers. The calculated band gaps from this model show better agreement with the reported experimental data than those predicted by the previous models. Because of a wide range of variations, the electrophilicity could be a better index for investigating the doping effect in polymers than the hardness.

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Phenotypic variability of parkin mutations in single kindred
Authors: Koentjoro Brianada , Park Jin‐Sung , Ha Ainhi Duy , Sue Carolyn M.
Published: July 2012

Background:

Mutations in parkin have been associated with autosomal recessive early‐onset Parkinson's disease (PD). Here, we report on unusual phenotypic variability within a family with mutations in parkin.

Methods:

The proband and her parents were clinically assessed. Mutation analysis was performed using genomic DNA and complementary DNA. The protein expression of Parkin and Mitofusin 2 was examined by western blotting.

Results:

The proband was a compound heterozygote with no detectable Parkin and presented with early‐onset PD. The father, a single heterozygote with reduced expression of Parkin, had mild loss of arm swing. The mother, who had only very mild rigidity, was unexpectedly found to be a homozygote with no Parkin expression. The proband, but not the parents, met the Queen Square Brain Bank criteria for PD. Parkin‐dependent ubiquitination of Mitofusin 2 was impaired in the mother and the proband.

Conclusion:

We report the first case of a homozygous mutation carrier in parkin who had no functional protein and only mild signs of parkinsonism in her seventh decade, whereas her daughter developed typical early‐onset PD. This family demonstrates phenotypic variability in parkin‐related parkinsonism. © 2012 Movement Disorder Society
Higher order modes in acoustically antiguiding optical fiber
Authors: Dragic Peter D. , Law Pi‐Cheng , Liu Yuh‐Shiuan
Published: July 2012

We present evidence of the presence of higher order acoustic modes in acoustically antiguiding optical fiber. Microwave heterodyne measurements (∼11 GHz) on a fiber with a pure silica core and F‐doped cladding reveal a Brillouin gain spectrum with two distinguishable acoustic modes. A simple model calculates the measured spectrum very well. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2347–2349, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27049
Comparison of compact electric‐LC resonators for negative permittivity metamaterials
Authors: Dhouibi Abdallah , Burokur Shah Nawaz , de Lustrac André , Priou Alain
Published: July 2012

Various easy made planar electric meta‐atoms are presented as alternative designs to the conventional electric‐LC resonator for achieving negative permittivity. Transforming the LC topology of the resonator helps to facilitate transposition of geometrical parameters for the optical regime and also to improve the metamaterial homogeneity. Our approach aims to simplify the resonator design and achieve a lower resonance frequency without being limited by fabrication techniques. A parametric sweep is performed to evaluate the influence of the different geometrical parameters on the resonance frequencies of the meta‐atoms. The electromagnetic behavior is investigated through both simulations and experiments in the microwave regime. Our results show that the developed meta‐atoms exhibit a purely strong electric response to normally incident radiation and can be used very effectively in producing materials with negative permittivity. For instance, a Z‐shaped structure is shown to present a higher effective medium ratio. The proposed meta‐atoms can find various applications in planar high‐frequency passive circuits due the simplicity of fabrication. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2287–2295, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27050
Compact fork stub‐loaded square open‐loop bandpass filter for VSAT applications
Authors: Maharjan Ram K. , Shrestha Bhanu , Kim Nam Young
Published: July 2012

A compact stub‐coupled microstrip square open‐loop resonator‐based bandpass filter (BPF) is proposed.In this work, a back‐to‐back fork‐shaped open stub and two attached stubs are internally accommodated inside the square loops using open gaps. Significantly, large coupling coefficient value can be obtained in the square open‐loop resonator using those loaded stubs. In this design structure, the inserted stubs enhance to couple the two loops electromagnetically to each other. The proposed filter has strong electric coupling, because the open sides of the two coupled loops are proximately placed face‐to‐face in parallel. Similarly, the rectangular stubs attached with the internal wall of loops help to connect magnetic couplings between the two loops, as a result, the mixed coupling generates strong electromagnetic coupling in the BPF with an adequate input reflection coefficient and broader bandwidth in required frequency band. The open‐loop BPF at 14.4 GHz is realized by an embedded open‐stub combined with attach‐stubs. The designed filter shows the simple topology, low insertion losses, and sharp rejections. The S‐parameter response of the fabricated filter closely matches with the simulation results and, therefore, the feasibility of the proposed filter is confirmed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2412–2416, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27054
Wavelength‐spacing tunable multiwavelength fiber optical parametric oscillator
Authors: Sun Bing , Hu Kai , Chen Daru , Wei Yizhen , Chen Hongzhi , Gao Shiming
Published: July 2012

We proposed a multiwavelength fiber optical parametric oscillator (MW‐FOPO) based on a tunable Mach–Zehnder interferometer.Multiwavelength lasing of the MW‐FOPO with a wavelength spacing of about 0.32 nm in a wavelength regime from 1515 to 1600 nm (for lasing wavelengths with the power that exceeds −60 dBm) is achieved. Wavelength spacing of the MW‐FOPO can be continuously tuned and multiwavelength lasing with wavelength spacings of 0.08, 0.16, 0.32 nm are demonstrated. The stability of the MW‐FOPO at room temperature is discussed and experimentally demonstrated. We also present the comparison of the output spectra between the MW‐FOPO and the multiwavelength Erbium‐doped fiber laser. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2405–2408, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27069
Dual‐wideband branch‐line coupler based on a loaded N‐segment SIR
Authors: Nosrati Mehdi , Daneshmand Mojgan
Published: July 2012

In this study, a novel topology of loaded N‐segment stepped‐impedance resonator (SIR) is introduced to control the frequency ratio between the second and first resonance frequencies of such resonator. The fundamental characteristic of such resonators, the frequency ratio between the second and first resonance frequencies, is targeted as a key factor in arbitrary tuning the resonance frequencies. It is shown that this factor can be determined in a ratio of 6.7: 2.7: 2.25 for the proposed, the conventional dual‐section and T‐shaped SIRs using a five‐segment SIR. This concept can be applied in the design of any dual‐band microwave components where a wide branch‐line couplers is chosen as a sample. It is demonstrated that the proposed topology not only provides more design flexibilities but also improves the performance of such components in terms of bandwidth enhancement, better return loss, and size reduction around 56%. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2300–2303, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27076
Design of small planar antennas based on double‐layered CRLH metamaterials
Authors: Abd El‐Raouf Hany E. , Zaheer Sulaiman Syed
Published: July 2012

This letter presents the design of a new efficient double negative metamaterial antennas. The design of the unit cell of these antennas is based on the composite right/left‐handed (CRLH) transmission line model. The zeroth‐order resonance of this kind of antennas depends mainly on the equivalent circuit of the unit cell and provides the opportunity to design the antenna with very small electrical size. The previous published results show that the conventional CRLH mushroom radiator suffers from narrow bandwidth and low gain. In this letter, we introduce a new method of design of CRLH metamaterial antennas to tackle the above problem using two layers of CRLH mushroom structure. The upper layer of the CRLH is used to reduce the reactance of the small antenna and to improve the matching between the antenna and the feeding line. The results at the zeroth‐order resonance show improvements in the antenna gain and bandwidth by introducing the upper layer. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2224–2229, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27078
Wideband divide‐by‐2 quadrature injection‐locked frequency dividers with large output voltage swing
Authors: Chou Li‐Te , Huang Jhin‐Fang , Jang Sheng‐Lyang
Published: July 2012

This letter presents a quadrature injection‐locked frequency divider (QILFD) to achieve high‐speed, wide‐locking range, accurate quadrature output phases, and large output voltage swing.The QILFD consists of two differential top‐series‐injected injection‐locked frequency dividers coupled by four parasitic bipolar junction transistors (BJTs). The MOSFET with the coupling BJT is used as a top‐series RF injector and linear mixer. The proposed QILFD has been implemented with the TSMC 0.13‐μm CMOS technology and the core power consumption is 6.02 mW at the supply voltage of 0.8 V. The operation range is from 9.2 to 12.8 GHz while the input power is 0 dBm. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2284–2287, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27089
Design of Ku‐band reflectarray using hexagonal patch with crossed slots
Authors: Park Jae Hyun , Choi Hak Keun , Kim Seon Hye
Published: July 2012

The microstrip reflectarray is rapidly becoming an attractive alternative solution to the traditional parabolic reflector antenna due to its various advantages, such as its high gain, narrow beam with low side lobes, light weight, and smaller volume. In this article, a microstrip reflectarray consisting of a hexagonal patch with crossed slots as the cell elements printed on a conductor‐backed substrate is proposed to replace the traditional parabolic reflector antenna. Using this type of cell element, the simulated results of the microstrip reflectarray demonstrate a radiation efficiency of over 60% at 12.5 GHz and a gain of over 26 dBi at 12–13.7 GHz. The experimental results show good agreement with the simulated ones, confirming the validity of the approach presented herein. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2383–2387, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27095
A Quad‐Band printed planar inverted‐F antenna with a quasi‐rectangular loop for mobile phones
Authors: Ahn Jungho , Choi Junho , Kim Seunghwan , Lee Jaeho , Kim Austin S. , Kim Y.‐S.
Published: July 2012

In this letter, a printed planar inverted‐F antenna is proposed for a quad‐band operation.The proposed quasi‐rectangular loop configuration yields the first and second resonant frequencies at 900 and 1800 MHz, respectively. The additional shorted strip on the bottom can expand the bandwidth at the upper band. The proposed antenna area is 8 × 38 mm2 and the ground size is 72 × 40 mm2. The measured impedance bandwidth, determined by 3:1 VSWR, has fully covered the GSM900 (880–960 MHz), DCS (1710–1880 MHz), PCS (1850–1990 MHz), and UMTS (1920–2170 MHz) frequency bands. The measured gain is higher than −1 dBi over the entire quad‐band. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2337–2341, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27099
Drain‐source voltage and current waveforms measurement method using harmonic ABCD matrices
Authors: Shin Suk‐Woo , Choi Jin‐Joo , Choi Jun‐Ho , So Joon‐Ho
Published: July 2012

In this article, a drain‐source voltage and current waveforms measurement method for a fabricated power amplifier is presented. Harmonic components of the drain‐source voltage and the current were obtained using measured output voltage and harmonic ABCD matrices of a load matching network. The drain‐source voltage and current waveforms of a fabricated power amplifier that is operated nonlinearly were successively measured using the proposed measurement method without any influence in the power amplifier operation. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2335–2337, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27100
Reliable gamma aminobutyric acid measurement using optimized PRESS at 3 T
Authors: Napolitano Antonio , Kockenberger Walter , Auer Dorothee P.
Published: July 2012

Gamma aminobutyric acid (GABA) is the most important inhibitory neurotransmitter in the central nervous system and there is strong interest in noninvasive measurement of GABA levels to assess GABAergic dysfunction in a number of psychiatric and neurological diseases. GABA detection by proton MR spectroscopy is challenging due to its low concentration as well as its strong overlap with more highly concentrated metabolites; therefore, editing techniques are typically required. In this study, the parameters of a standard point resolved spectroscopy (PRESS) sequence were optimized through repeated simulations to reliably and simultaneously detect GABA and glutamate at 3 T. Experimental validation of the optimized sequence parameters of echo time (TE1) = 15 ms and TE = 105 ms and careful postprocessing with realignment yielded reliable GABA estimates in the anterior cingulate cortex and precuneus region with test‐retest coefficient of variation of 10.4%. The achieved reproducibitilty was thus similar to published MEGA‐PRESS data despite smaller voxels and shorter scan time in this study. In conclusion, the optimized sequence parameters reported here allow reliable GABA estimation without additional hardware or software adaptation on clinical scanners. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Routing and scheduling for energy and delay minimization in the powerdown model
Authors: Andrews Matthew , Fernández Anta Antonio , Zhang Lisa , Zhao Wenbo
Published: July 2012

Energy conservation is drawing increasing attention in data networking. As networks are designed for peak traffic, network elements typically operate at full speed and consume maximum power even when carrying low traffic. One school of thought believes that a dominant amount of power saving comes from turning off network elements. The difficulty is that transitioning between the active and sleeping modes consumes considerable energy and time. This results in an obvious trade‐off between saving energy and provisioning performance guarantees such as end‐to‐end delays. We study the following routing and scheduling problem in a network in which each network element either operates in the full‐rate active mode or the zero‐rate sleeping mode. For a given network and traffic matrix, routing determines the path that each traffic stream traverses. For frame‐based periodic scheduling, a schedule determines the active period per element within each frame and prioritizes packets within each active period. For a line topology, we present a schedule with close‐to‐minimum delay for a minimum active period per element. For an arbitrary topology, we partition the network into a collection of lines and use the near‐optimal schedule along each line. Additional delay is incurred only when a path switches from one line to another. By minimizing the number of switchings via routing, we show a logarithmic approximation for both power consumption and end‐to‐end delays. If routing is given as input, we present two schedules one of which has active period proportional to the traffic load per network element, and the other has active period proportional to the maximum load over all elements. The end‐to‐end delay of the latter is much improved compared to the delay for the former. This demonstrates the trade‐off between power and delay. Finally, we provide simulation results to validate our algorithmic approaches. © 2012 Wiley Periodicals, Inc. NETWORKS, 2013
First Approach to Study the Presence of Domesticated Camelids (Lama glama) in the Chaco‐Santiago Region, a Marginal Zone of the South Central Andes
Authors: del Papa Luis M.
Published: July 2012

We analysed bone remains of camelids from the Maquijata site, assigned to the late pottery‐making and farming stage (ca. 800–400 BP), in order to differentiate between domestic and wild species in the Chaco‐Santiago archaeological region. This region is considered marginal to the Argentine Northwest regarding its cultural development and has received less attention than other regions. South American camelids have been one of the major resources in this continent, with domestication recorded in the South Central Andes at around 4400–3000 BP. We applied osteometric techniques and multivariate statistical analyses to proximal phalanges; the results showed interspecific differentiation of archaeological specimens, though with some methodological application issues. These results are the first contribution regarding the presence of domesticated animals in the study area. Copyright © 2012 John Wiley & Sons, Ltd.
Notch‐3 receptor activation drives inflammation and fibrosis following tubulointerstitial kidney injury
Authors: Djudjaj Sonja , Chatziantoniou Christos , Raffetseder Ute , Guerrot Dominique , Dussaule Jean‐Claude , Boor Peter , Kerroch Monique , Hanssen Lydia , Brandt Sabine , Dittrich Annemarie , Ostendorf Tammo , Floege Jürgen , Zhu Cheng , Lindenmeyer Maja , Cohen Clemens D , Mertens Peter R
Published: July 2012

Kidney diseases impart a vast burden on affected individuals and the overall health care system. Progressive loss of renal parenchymal cells and functional decline following injury are often observed. Notch‐1 and ‐2 receptors are crucially involved in nephron development and contribute to inflammatory kidney diseases. We specifically determined the participation of receptor Notch‐3 following tubulointerstitial injury and in inflammatory responses. Here we show by heat map analyses that Notch‐3 transcripts are up‐regulated in human kidney diseases. A similar response was corroborated with kidney cells following TGF‐β exposure in vitro. The murine unilateral ureteral obstruction (UUO) model mirrors hallmarks of tubulointerstitial injury and damage. A subset of tubular and interstitial cells demonstrated up‐regulated Notch‐3 receptor expression in diseased animals. We hypothesized a relevance of Notch‐3 receptors for the chemotactic response. To address this question, animals with genetic ablation of receptor Notch‐3 were analysed following UUO. As a result, we found that Notch‐3‐deficient animals are protected from tubular injury and cell loss with significantly reduced interstitial collagen deposition. Monocytic cell infiltration was significantly reduced and retarded, likely due to abrogated chemokine synthesis. A cell model was set up that mimics enhanced receptor Notch‐3 expression and activation. Here a pro‐mitogenic response was seen with activated signalling in tubular cells and fibroblasts. In conclusion, Notch‐3 receptor fulfils non‐redundant roles in the inflamed kidney that may not be replaced by other Notch receptor family members. Thus, specific blockade of this receptor may be suitable as therapeutic option to delay progression of kidney disease. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Purification of Phenylalkanoids and Monoterpene Glycosides from Rhodiola rosea L. Roots by High‐speed Counter‐current Chromatography
Authors: Mudge Elizabeth , Lopes‐Lutz Daise , Brown Paula N. , Schieber Andreas
Published: July 2012

Introduction

Rhodiola rosea L. is a medicinal herb used for its adaptogenic properties. The main active components are the phenylpropanoids collectively referred to as rosavins.

Objectives

To develop an isolation method for phytochemicals present in Rhodiola rosea roots using high‐speed counter‐current chromatography (HSCCC).

Methodology

The roots of Rhodiola rosea were extracted with methanol and fractionated using liquid–liquid partition and polyamide column clean‐up. The purified fraction (100 mg) was subjected to semi‐preparative HSCCC using the two‐phase solvent system ethyl acetate:butanol:water (3:2:5). The head‐to‐tail elution mode was employed with a flow rate of 1.5 mL/min and a rotary speed of 1000 rpm.

Results

The separation yielded six main fractions with four components more than 90% pure. The sixth fraction was further purified using semi‐preparative HPLC with a Synergi‐hydro RP C18‐column to obtain rosin and geranyl 1‐O‐α‐l‐arabinopyranosyl(1 → 6)‐β‐d‐glucopyranoside. The main components isolated were rosavin (3.4 mg, 97% purity), salidroside (0.5 mg, 90% purity), benzyl‐O‐β‐d‐glucopyranoside (1.2 mg, 85% purity), rosarin (1.3 mg, 99% purity), rosiridin (1.8 mg, 92% purity), rosin (1.2 mg, 95% purity) and geranyl 1‐O‐α‐l‐arabinopyranosyl(1 → 6)‐β‐d‐glucopyranoside (6.5 mg, 97% purity). The identity and purity of these components were confirmed using ultrafast liquid chromatography–diode‐array detector–MS/MS analysis, 1 H‐ and 13 C‐NMR spectroscopy.

Conclusion

High‐speed counter‐current chromatography was successful in the isolation of several phytochemicals present in Rhodiola rosea roots, including two components that are not commercially available. Copyright © 2012 John Wiley & Sons, Ltd.