bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of Single‐Layered Double‐Hydroxide Platelets in Poly(vinylpyrrolidone) and Alginate Medium: Conductive, Capacitive, and Dielectric Properties of the Hybrid Films
Authors: Leroux Fabrice , Chabrol Karine , Thérias Sandrine , Gardette Jean‐Luc , de Roy André
Published: September 2012

Direct synthesis from an adapted salt coprecipitation of single‐crystalline layered double‐hydroxide (LDH) platelets can be realized by using polyvinylpyrrolidone (PVP) assisted by an organo‐modifying agent, alginate (ALG). The formation of LDH inorganic platelets with a Zn/Al cation composition of 2:1 was demonstrated by TEM observations as well as by a topotactic restacking reaction that used the terephthalate molecule pillaring effect. From the perspective of PVP, LDH platelets can be viewed as hybrid filler. With regards to the inorganic platelets, the dispersive medium supplied by PVP chains in association with the biopolymer is an elegant process for generating single platelets, the whole of which can form an exfoliated polymer nanocomposite structure. The resulting transparent, crack‐free PVP films obtained from solvent casting were studied by electrochemical impedance spectroscopy (EIS) to evaluate their conductive, capacitive, and dielectric properties. Single LDH platelets have been found to be beneficial to the enhancement of the ionic conductivity, and values up to six orders of magnitude higher than PVP were reached for PVP LDH film that contains LiClO4 salt. In particular, a reversible behavior upon temperature cycling was observed for the latter in association with low activation energy. The linear Arrhenius‐type dependence of the conductivity was disrupted at 310 K, and this was also proven by the dielectric behavior expressed by the loss modulus M″(ω) as a function of the temperature as well as by an Argand diagram. Such an unexpected phenomenon is tentatively explained by a drastic change in the dielectric relaxation strength observed versus temperature. Such an easy, environmentally friendly, solvent‐free, and scalable one‐step synthesis to yield single platelets and ultimately polymer films bodes well for other chemical compositions in terms of hybrid assemblies as well as polymers.
The Trifluoromethyl Group in Transition Metal Chemistry
Authors: García‐Monforte M. Angeles , Martínez‐Salvador Sonia , Menjón Babil
Published: September 2012

A general overview on trifluoromethyl–TM derivatives (TM = transition metal) is presented with special focus on those compounds that have been isolated or at least detected in solution. Representative examples have been selected in order to illustrate the main structural features and/or reactivity patterns.
Synthesis and Properties of Dinuclear μ‐Oxodiiron(III) Complexes of Amide‐Based Macrocyclic Ligands
Authors: Kumar Sushil , Vaidya Shefali , Pissas Michael , Sanakis Yiannis , Gupta Rajeev
Published: September 2012

We report the syntheses, structural, Mössbauer, magnetic, and redox characterization of a series of μ‐oxido‐bridged diiron(III) complexes in a set of 13‐membered amide‐based macrocyclic ligands that contain electron‐donating and ‐withdrawing substituents (–H, –Cl, and –CH3) on the ligand periphery. For all three complexes, the Mössbauer spectra indicate that two iron sites are indistinguishable, a fact that is well supported by X‐ray crystallographic results. The three complexes exhibit almost identical isomer shifts but distinctively different quadruple splitting values. The variable‐temperature magnetic susceptibility measurements show that the unsupported single μ‐oxido group mediates a strong antiferromagnetic coupling between two FeIII ions. The three diiron complexes show quite different magnetic coupling (J = 191, 194, and 230 cm–1, respectively; Hiso = J S1·S2) that has been related to the structural differences. We also show that the electron‐donating and ‐withdrawing substituents present on the ligands influence the redox properties.
Genomic analysis of Saccharomyces cerevisiae isolates that grow optimally with glucose as the sole carbon source
Authors: Aragon Anthony D. , Torrez‐Martinez Norah , Edwards Jeremy S.
Published: September 2012

A population of Saccharomyces cerevisiae was cultured for approximately 450 generations in the presence of high glucose to select for genetic variants that grew optimally under these conditions. Using the parental strain BY4741 as the starting population, an evolved culture was obtained after aerobic growth in a high glucose medium for approximately 450 generations. After the evolution period, three single colony isolates were selected for analysis. Next‐generation Ion Torrent sequencing was used to evaluate genetic changes. Greater than 100 deletion/insertion changes were found with approximately half of these effecting genes. Additionally, over 180 SNPs were identified with more than one‐quarter of these resulting in a nonsynonymous mutation. Affymetrix DNA microarrays and RNseq analysis were used to determine differences in gene expression in the evolved strains compared to the parental strain. It was established that approximately 900 genes demonstrated significantly altered expression in the evolved strains relative to the parental strain. Many of these genes showed similar alterations in their expression in all three evolved strains. Interestingly, genes with altered expression in the three evolved strains included genes with a role in oxidative metabolism. Overall these results are consistent with the physiological observations of optimal growth with glucose as the carbon source. Namely, the decreased ethanol production suggest that the underlying metabolism switched from fermentation to respiration during the selection for optimal growth on glucose.
Summary of in vitro genetic toxicology assay results: Expected and unexpected effects of recent study design modifications
Authors: Clarke Jane J. , Lawlor Timothy E. , Madraymootoo Wannie , Pant Kamala , Young Robert R. , Wagner Valentine O. , Aardema Marilyn J.
Published: September 2012

Key modifications to in vitro genetic toxicology testing have been made in the last 5 years including the use of optimization approaches such as structure–activity relationships and screening assays to identify and eliminate potentially genotoxic chemicals from further consideration, better guidance on cytotoxicity assessment and dose selection, and greater use of p53‐competent human cells. To determine the effect of these changes on testing outcomes, the pattern of positive results across assays conducted by BioReliance from 2005 to 2010 was examined. Data were tabulated for good laboratory practice (GLP)‐compliant Ames, mouse lymphoma (MLA), chromosome aberration in Chinese hamster ovary (CHO) cells, and in human peripheral blood lymphocytes (HPBL) assays along with non‐GLP screening Ames assays. A decrease in percentage of positive results in MLA and CHO chromosome aberration assays was observed, whereas the percentage of positive Ames assays remained consistent. This was not unexpected because MLA and CHO cytogenetic assays have undergone the most substantive changes (e.g., the establishment of the Global Evaluation Factor for the MLA and the use of the relative increase in cell counts in CHO chromosome aberration assays). Over the last 5 years, there has been an increase in the percentage of positive results observed in the chromosome aberration assay in HPBL. It is speculated that this may have led to an increase in HPBL‐positive results if the chemicals routed to HPBL had previous positive genotoxicity results. Another factor may be the lack of a reliable cytotoxicity measurement in the HPBL assay. Environ. Mol. Mutagen., 2012. © 2012 Wiley Periodicals, Inc.
Investigation into the metabolism of 1,8‐cineole in an intestinal cell culture model and acquisition of its immune‐modulatory effect via gene expression analysis
Authors: Müller Jakob , Gruner Natalie , Almstätter Isabella , Kirsch Frauke , Buettner Andrea , Pfaffl Michael W
Published: September 2012

1,8‐Cineole, a common and widely used odorant with antiphlogistic and anti‐inflammatory properties, was investigated in this study with regard to potential physiological effects targeting mainly its intestinal effects. Accordingly, the aim of the study was to utilize a combinatory methodological approach to both monitor potential biotransformatory effects on a chemo‐analytical basis, as well as physiological and immunological tools to monitor further effects of biofeedback. Reverse transcription quantitative real‐time polymerase chain reaction was used to monitor the occurrence of relative expression changes for particular marker genes, following 1,8‐cineole treatment. Furthermore, a potential effect of 1,8‐cineole on the proliferation and fitness of the intestinal cells using impedance sensing was studied. Generally, our studies showed that the applied model system did neither lead to any significant metabolite formation, nor did the applied dosages result in any major modifications with regard to gene expression. Also, it was shown that cineole had no effect on the intestinal porcine epithelial cells applied in pharmacological or physiological concentrations; neither during the attachment and spreading process nor on confluent cell layers. Only the exposure to high concentrations of cineole (> 1 g/l) affected the cells and led to massive cell detachment. Overall, our studies show that even common higher 1,8‐cineole dosages do not seem to lead to any major physiological or aversive response, only until a critical concentration is reached that then directly leads to cell death within the intestinal model. Copyright © 2012 John Wiley & Sons, Ltd.
Machaeridians from the Middle and Upper Ordovician of the Argentine Precordillera
Authors: Ortega G. , Albanesi G. L. , Zeballo F. J.
Published: September 2012

The machaeridians are marine Palaeozoic annelids, which developed a dorsal skeleton composed of calcite sclerites, achieving a world‐wide distribution from the Early Ordovician to the Middle Permian. The absence of records from this group is notable in Argentina in spite of intense studies of Palaeozoic rocks. This fact can be explained by biases in sampling or because of preservation problems. Machaeridian sclerites of the families Plumulitidae and Turrilepadidae collected in Middle and Upper Ordovician rocks from the San Juan Precordillera, Argentina, are described here for the first time. Plumulites sp. is recorded in early Darriwilian strata from the Gualcamayo Formation exposed in the western flank of the Cerro La Chilca locality, and from the Las Aguaditas Formation in the Quebrada de Las Aguaditas section. Plumulitid and turrilepadid sclerites are described from the upper member of the Los Azules Formation (late Sandbian) in the Cerro Viejo de Huaco area. The material of the Los Azules Formation is the first record of turrilepadids in Sandbian rocks, which are scarce in Ordovician successions. The referred strata bear pelagic, benthic and nektobenthic faunal assemblages, constituting a similar taphocoenosis preserved in shales and calcareous silty shales related to transgressive events. The record of machaeridians expands our knowledge of the Ordovician biotas from Argentina and provides new information on the palaeobiogeographical distribution of this Palaeozoic annelid group. Copyright © 2012 John Wiley & Sons, Ltd.
Transfer of training: Written self‐guidance to increase self‐efficacy and interviewing performance of job seekers
Authors: Shantz Amanda , Latham Gary P.
Published: September 2012

Subsequent to training IT professionals ( n = 35) in skills for performing effectively in a selection interview, 16 were randomly assigned to a transfer of training intervention, written self‐guidance (WSG). This methodology is based on social cognitive and self‐persuasion theories. The results showed that WSG resulted in significantly higher ratings from an interviewer than did those in the control group. Self‐efficacy for interviewing skill mediated the relationship between WSG and performance. A content analysis of the WSG letters showed that the use of self‐affirming and self‐relevant statements was positively related to performance in the selection interview. © 2012 Wiley Periodicals, Inc.
Loop‐linker PCR: An advanced PCR technique for genome walking
Authors: Trinh Quoclinh , Shi Hui , Xu Wentao , Hao Junran , Luo Yunbo , Huang Kunlun
Published: September 2012

In this article, we developed a novel PCR method, termed loop‐linker PCR, to isolate flanking sequences in transgenic crops. The novelty of this approach is its use of a stem‐loop structure to design a loop‐linker adapter. The adapter is designed to form a nick site when ligated with restricted DNA. This modification not only can prevent the self‐ligation of adapters but also promotes the elongation of the 3′ end of the loop‐linker adapter to generate a stem‐loop structure in the ligation products. Moreover, the suppressive effect of the stem‐loop structure decreases nonspecific amplification and increases the success rate of the approach; all extension products will suppress exponential amplification except from the ligation product that contains the specific primer binding site. Using this method, 442, 1830, 107, and 512 bp left border flanking sequences were obtained from the transgenic maizes LY038, DAS‐59122‐7, Event 3272, and the transgenic soybean MON89788, respectively. The experimental results demonstrated that loop‐linker PCR is an efficient, reliable, and cost‐effective method for identifying flanking sequences in transgenic crops and could be applied for other genome walking applications. © 2012 IUBMB IUBMB Life, 64(10): 841–845, 2012
Synthesis of biologically active and photostable rigid poly(vinyl chloride)
Authors: Rabie Samira T. , El‐Saidi Manal M. T. , Mohamed Nadia R.
Published: September 2012

N,N‐Dimethyl‐N′‐(6‐oxo‐2‐thioxo‐1H‐pyrimidine‐4‐yl)formamidine has been synthesized and introduced as a substituent in poly(vinyl chloride) (PVC) chains via a chemical reaction. Both the dimethyl derivative and the modified PVC have been characterized via spectroscopic analyses and their biological activities have been evaluated. Both IR and 1H NMR spectral data confirm the incorporation of the newly prepared bioactive dimethyl pyrimidine derivative in the polymeric chains. The dimethyl pyrimidine derivative has exhibited good antibacterial and antifungal activities. The modified PVC shows higher antibacterial effects than that of the blank one. Photostabilizing efficiency of the modified PVC is determined by measuring the changes that occurred in the molecular weights of modified PVC samples after UV irradiation using the gel permeation chromatography technique. The extent of discoloration of the photodegraded modified PVC samples has also been measured. The results have been compared with that of the blank PVC and that of the PVC stabilized with phenyl salicylate as a reference UV absorber. The lower decrease in the values of weight average molecular weight, Mw, at the first stages of UV irradiation and the absence of crosslinking at the latter stages of irradiation confirms the photostability of the modified PVC. The extent of discoloration of the modified sample is also decreased when compared with the blank and stabilized PVC samples. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:3503–3510, 2012.
Single‐breath xenon polarization transfer contrast (SB‐XTC): Implementation and initial results in healthy humans
Authors: Muradyan Iga , Butler James P. , Dabaghyan Mikayel , Hrovat Mirko , Dregely Isabel , Ruset Iulian , Topulos George P. , Frederick Eric , Hatabu Hiroto , Hersman William F. , Patz Samuel
Published: September 2012

Purpose:

To implement and characterize a single‐breath xenon transfer contrast (SB‐XTC) method to assess the fractional diffusive gas transport F in the lung: to study the dependence of F and its uniformity as a function of lung volume; to estimate local alveolar surface area per unit gas volume SA/VGas from multiple diffusion time measurements of F; to evaluate the reproducibility of the measurements and the necessity of B1 correction in cases of centric and sequential encoding.

Materials and Methods:

In SB‐XTC three or four gradient echo images separated by inversion/saturation pulses were collected during a breath‐hold in eight healthy volunteers, allowing the mapping of F (thus SA/VGas) and correction for other contributions such as T1 relaxation, RF depletion and B1 inhomogeneity from inherently registered data.

Results:

Regional values of F and its distribution were obtained; both the mean value and heterogeneity of F increased with the decrease of lung volume. Higher values of F in the bases of the lungs in supine position were observed at lower volumes in all volunteers. Local SA/VGas (with a mean ± standard deviation of SA/VGas = 89±30 cm−1) was estimated in vivo near functional residual capacity. Calibration of SB‐XTC on phantoms highlighted the necessity for B1 corrections when k‐space is traversed sequentially; with centric ordering B1 distribution correction is dispensable.

Conclusion:

The SB‐XTC technique is implemented and validated for in vivo measurements of local SA/VGas. J. Magn. Reson. Imaging 2013;37:457–470. © 2012 Wiley Periodicals, Inc.
Electrical–thermal modeling of through‐silicon via (TSV) arrays in interposer
Authors: Xie Jianyong , Xie Biancun , Swaminathan Madhavan
Published: September 2012

In this paper, electrical–thermal modeling of through‐silicon via (TSV) arrays is presented. In order to address the thermal effect on TSVs, TSV array design and modeling need to take into account the effect of realistic system thermal profile to meet design budget. To obtain temperature estimation for a 3D system, cascadic multigrid method is employed using an initial guess obtained by simulation using equivalent thermal conductivity to represent critical regions. By considering the thermal effect on electrical conductivities of TSV conductor and silicon substrate, the electrical–thermal modeling of TSV array in the interposer is carried out using cylindrical modal basis functions. The temperature effect on TSV insertion loss, crosstalk, and RLCG parameters are discussed with examples along with correlation with measurements. Copyright © 2012 John Wiley & Sons, Ltd.
Influence of backbone length and synthetic mutations on orientation of neurotensin fragments adsorbed onto a colloidal silver surface: SERS studies
Authors: Proniewicz Edyta , Pienpinijtham Prompong , Ozaki Yukihiro , Kim Younkyoo , Proniewicz Leonard M.
Published: September 2012

Neurotensin (NT) is a naturally occurring neurotransmitter that mediates the metabotropic seven‐transmembrane G protein‐coupled receptors, namely NTR1s, richly expressed on tumor surface. Therefore, mutated active molecular fragments of NT that possess selective antagonist or weak agonist properties and the high affinity to NTR1 have attracted considerable interest for use in thrombus, inflammation, and imaging/treatment of tumors. In this work, SERS spectra of three N‐terminal fragments of human NT (NT1‐6, NT1‐8, and NT1‐11) and six specifically mutated C‐terminal fragments of human NT, including NT8‐13, [Dab9]NT8‐13, [Lys8,Lys9]NT8‐13, [Lys8‐(®)‐Lys9]NT8‐13, [Lys9,Trp11,Glu12]NT8‐13, and NT9‐13, adsorbed onto nanometer‐sized colloidal silver particles in an aqueous solution at pH level of the solution 2 are presented. A comparison was made between the structures of the native and mutated fragments to determine how changes in peptide length and mutations of the structure influenced the NT adsorption properties. Based on the interpretation of the obtained data, we showed that all of the investigated NT fragments, excluding [Lys9,Trp11,Glu12]NT8‐13, tended to adsorb on the silver surface mainly through the L‐tyrosine residue and the carboxylate group. The Tyr ring lied more‐or‐less flat on the silver surface. The hydrogen atom from the phenol group dissociated upon binding. On the other hand, [Lys9,Trp11,Glu12]NT8‐13 bound to this substrate through the close to vertical co‐pyrrole ring of the indole ring (Trp11) and –COO‐.

Comparison of the presented data with those obtained earlier for NT allows to suggest that in the case of naturally occurring neurotensin, both Tyr residues together with the carboxylate group play crucial role in the binding to the nanometer‐sized colloidal silver particles. This geometry of binding forces the NT molecule to lay flat on the surface. Copyright © 2012 John Wiley & Sons, Ltd.
DFT‐assisted interpretation of the Raman spectra of hydrogen‐ordered ice XV
Authors: Whale Thomas F. , Clark Stewart J. , Finney John L. , Salzmann Christoph G.
Published: September 2012

The vibrational spectra of the condensed phases of water often show broad and strongly overlapping spectral features which can make spectroscopic interpretations and peak assignments difficult. The Raman spectra of hydrogen‐ordered H2O and D2O ice XV are reported here, and it is shown that the spectra can be fully interpreted in terms of assigning normal modes to the various spectral features by using density functional theory (DFT) calculations. The calculated lattice‐vibration spectrum of the experimental antiferroelectric structure is in good agreement with the experimental data whereas the spectrum of a ferroelectric Cc structure, which computational studies have suggested as the crystal structure of ice XV, differs substantially. Moreover, the calculated coupled O–H stretch spectrum also seems in better agreement with the experiment than the calculated spectrum for the Cc structure. Both the hydrogen bonds as well as the covalent bonds appear to be stronger in hydrogen‐ordered ice XV than in the hydrogen‐disordered counterpart ice VI. A new type of stretching mode is identified, and it is speculated that this kind of mode might be relevant for other condensed water phases as well. Furthermore, the ice XV spectra are compared to the spectra of ice VIII which is the only other high‐pressure phase of ice for which detailed spectroscopic assignments have been made so far. In summary, we have established a link between crystallographic data and spectroscopic information in the case of ice XV by using DFT‐calculated spectra. Such correlations may eventually help interpreting the vibrational spectra of more structurally‐disordered aqueous systems. Copyright © 2012 John Wiley & Sons, Ltd.
Estimation of signal backgrounds on multivariate loadings improves model generation in face of complex variation in backgrounds and constituents
Authors: Beattie J. Renwick , McGarvey John J.
Published: September 2012

The present study is designed to understand further implications of using multivariate loadings for the correction of background signal, which has previously been shown to be highly reproducible even for very low quality signals. Singular value decomposition (SVD)‐based background correction was compared with the traditional per‐signal paradigm for a biomedical dataset to generate qualitative and quantitative models. The qualitative effect on a principal component analysis model and the quantitative effect on a partial least square regression model were assessed for these background correction methods. The chosen quantitative parameter was the concentration of a pathologically relevant protein modification, pentosidine. Of the approaches tested, the SVD‐based paradigm provided the regression model with the highest correlations, highest accuracy (lowest standard error of prediction) and repeatability (lowest sampling error). Contrasted against the traditional approaches, it was determined that the improved accuracy and repeatability of the SVD‐based approach arises from its ability to simultaneously handle very complex background shapes alongside the complex variation in biochemical species that resulted in Raman signals with incompatible baseline regions. A better understanding of the interaction of SVD‐based baseline correction, and data will give the reader more insight into the potential applicability of the procedure for other datasets. Copyright © 2012 John Wiley & Sons, Ltd.
Network meta‐analysis, electrical networks and graph theory
Authors: Rücker Gerta
Published: September 2012

Network meta‐analysis is an active field of research in clinical biostatistics. It aims to combine information from all randomized comparisons among a set of treatments for a given medical condition. We show how graph‐theoretical methods can be applied to network meta‐analysis. A meta‐analytic graph consists of vertices (treatments) and edges (randomized comparisons). We illustrate the correspondence between meta‐analytic networks and electrical networks, where variance corresponds to resistance, treatment effects to voltage, and weighted treatment effects to current flows. Based thereon, we then show that graph‐theoretical methods that have been routinely applied to electrical networks also work well in network meta‐analysis. In more detail, the resulting consistent treatment effects induced in the edges can be estimated via the Moore–Penrose pseudoinverse of the Laplacian matrix. Moreover, the variances of the treatment effects are estimated in analogy to electrical effective resistances. It is shown that this method, being computationally simple, leads to the usual fixed effect model estimate when applied to pairwise meta‐analysis and is consistent with published results when applied to network meta‐analysis examples from the literature. Moreover, problems of heterogeneity and inconsistency, random effects modeling and including multi‐armed trials are addressed. Copyright © 2012 John Wiley & Sons, Ltd.
A Kernel‐Based Method for Assessing Uncertainty on Individual QSAR Predictions
Authors: Tebby Cleo , Mombelli Enrico
Published: September 2012

The assessment of uncertainty attached to individual predictions is now a priority for sound decision‐making in risk assessment. QSAR predictive uncertainty is affected by a variety of factors related to the quality of the training set data, the adopted statistical models, and the distance between the query chemical and the training set. We developed a method to quantify uncertainty associated with individual linear QSAR predictions that integrates both model and experimental error uncertainty and that defines an applicability domain based on the density of training set data. Our method is based on chemical spaces defined by latent variables identified by Partial Least Squares (PLS) regressions. The method provides a kernel regression estimate of the activity of interest as well as a measure of predictive uncertainty based on a mathematical estimation of the domain of applicability and on local propagation of uncertainty associated with training set data.
Extending the operation frequencies of standard coaxial‐to‐microstrip connectors
Authors: Li Eric S. , Cheng Jui‐Ching , Tai Wei‐Yu
Published: September 2012

A new connector for coaxial‐to‐microstrip transitions is proposed. The structure designed for the transformation of the electromagnetic field distributions of a coaxial line and a microstrip line consists of two blocks split from a metallic ring and two parallel arrays of via holes embedded in the substrate of the microstrip line. Insertion loss caused by a field discontinuity at their transition is reduced, particularly at higher frequencies. Thus, the transmission passband of the transition is extended. A prototype of the new connector is prepared and its transition to a microstrip line with two embedded via arrays is simulated and measured for a design example. The results indicate that the proposed design can improve the 1‐dB passband of the transition by more than 60% compared to the conventional design. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2716–2719, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27165
Analog fiber‐optic links employing cascaded phase modulation stages
Authors: Urick Vincent J. , McKinney Jason D. , Diehl John F. , Singley Joseph M. , Williams Keith J.
Published: September 2012

An analysis of microwave‐photonic links using a series of external phase modulators is presented.Experimental results for a cascade of two modulation stages are used as a proof of principle and agree with the theoretical predictions. Such architectures can be used to improve the performance in external‐modulation analog fiber‐optic links. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2797–2801, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27193
A 0.9–3.5 GHz high linearity, good efficiency CMOS broadband power amplifier using stagger tuning technique
Authors: Sapawi Rohana , Pokharel Ramesh K. , Awang Mat Dayang Azra , Kanaya Haruchi , Yoshida Keiji
Published: September 2012

A simple CMOS broadband power amplifier design with high linearity and good efficiency is proposed.The proposed power amplifier design employed stagger tuning technique that consist of two stages amplifier with different resonant frequencies to obtain a wider bandwidth from 0.9 to 3.5 GHz and low power consumption. To obtain high linearity self‐biased circuit is employed at the first stage of amplifier. The measurement results indicated that the proposed design achieves average gain of 8.5 dB, an input return loss (S11) less than −3 dB and output return loss (S22) less than −5 dB. High linearity, that is, IIP3 of 13.4 dBm at 2 GHz, power added efficiency of 34% is obtained while consuming 24.4 mW power from 1.5 V supply voltage. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2881:2884, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27212
SIOP PODC: Clinical guidelines for the management of children with Wilms tumour in a low income setting
Authors: Israels Trijn , Moreira Claude , Scanlan Trish , Molyneux Liz , Kampondeni Sam , Hesseling Peter , Heij Hugo , Borgstein Eric , Vujanic Gordan , Pritchard‐Jones Kathy , Hadley Larry
Published: September 2012

Wilms tumour is a relatively common and curable paediatric tumour. Known challenges to cure in low income countries are late presentation with advanced disease, malnutrition, failure to complete treatment and limited facilities. In this article, management recommendations are given for a low income setting where only the minimal requirements for treatment with curative intent are available (setting 1). These include general management, supportive care, social support and registration of patients. Recommendations specific for Wilms tumour care include diagnostic procedures with emphasis on the role of ultrasonography, preoperative chemotherapy with a reduced dosage for malnourished children and postoperative chemotherapy based on surgical staging. Pediatr Blood Cancer 2013; 60: 5–11. © 2012 Wiley Periodicals, Inc.
Proteome variation among Filifactor alocis strains
Authors: Aruni A. Wilson , Roy Francis , Sandberg Lawrence , Fletcher Hansel M.
Published: September 2012

Filifactor alocis, a Gram‐positive anaerobic rod, is now considered one of the marker organisms associated with periodontal disease. Although there was heterogeneity in its virulence potential, this bacterium was shown to have virulence properties that may enhance its ability to survive and persist in the periodontal pocket. To gain further insight into a possible mechanism(s) of pathogenesis, the proteome of F. alocis strains was evaluated. Proteins including several proteases, neutrophil‐activating protein A and calcium‐binding acid repeat protein, were identified in F. alocis. During the invasion of HeLa cells, there was increased expression of several of the genes encoding these proteins in the potentially more virulent F. alocis D‐62D compared to F. alocis ATCC 35896, the type strain. A comparative protein in silico analysis of the proteome revealed more cell wall anchoring proteins in the F. alocis D‐62D compared to F. alocis ATCC 35896. Their expression was enhanced by coinfection with Porphyromonas gingivalis. Taken together, the variation in the pathogenic potential of the F. alocis strains may be related to the differential expression of several putative virulence factors.
Assembly of prototype foamy virus strand transfer complexes on product DNA bypassing catalysis of integration
Authors: Yin Zhiqi , Lapkouski Mikalai , Yang Wei , Craigie Robert
Published: September 2012

Integrase is the key enzyme that mediates integration of retroviral DNA into cellular DNA which is essential for viral replication. Inhibitors of HIV‐1 that target integrase recognize the nucleoprotein complexes formed by integrase and viral DNA substrate (intasomes) rather than the free enzyme. Atomic resolution structures of HIV‐1 intasomes are therefore required to understand the mechanisms of inhibition and drug resistance. To date, prototype foamy virus (PFV) is the only retrovirus for which such structures have been determined. We show that PFV strand transfer complexes (STC) can be assembled on product DNA without going through the normal forward reaction pathway. The finding that a retroviral STC can be assembled in this way may provide a powerful tool to alleviate the obstacles that impede structural studies of nucleoprotein intermediates in HIV‐1 DNA integration.
The shape of order in glasses
Authors: Chechetkina E. A.
Published: September 2012

The chemical bond approach to the glassy state is discussed. It is based on two concepts: Ovshinsky's idea of bond option as a necessary condition for amorphization, and Dembovsky's notions about hypervalent bonds (HVB) as alternative bonding state responsible for glass specificity and glass formation at all. The third idea is self‐organization of HVBs in the form of a bond wave, which provides an interconnected interpretation of three structural levels: short‐range order that is different at around HVB and far outside it, medium‐range order in the wavefronts populated with HVB, and long‐range order due to the bond wave itself. Experimental evidences and practical consequences of the bond‐wave picture are discussed.
An improved silicon‐oxide‐based intermediate‐reflector for micromorph solar cells
Authors: Kirner Simon , Calnan Sonya , Gabriel Onno , Neubert Sebastian , Zelt Matthias , Stannowski Bernd , Rech Bernd , Schlatmann Rutger
Published: September 2012

In this paper, we report on the development of an n‐type silicon oxide intermediate reflector (SOIR) for a‐Si:H/µc‐Si:H tandem solar cells produced in an industrial‐type AKT1600 PECVD reactor. A comparison to a tunnel recombination junction with µc‐SiOx in the p‐layer is made. Lower fill factors, resulting from the implementation of the SOIR, could be avoided by the deposition of a thin n‐doped microcrystalline silicon (µc‐Si) recombination layer after the SOIR. A cell efficiency of 9.5% after 168 h of light soaking at 50 °C and 1 sun was reached on commercially available SnO2:F front TCO, which is a 2% relative increase over a similar cell without the SOIR. Possible explanations for the role of this recombination layer are discussed (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stable‐isotope labeling and probing of recent photosynthates into respired CO2, soil microbes and soil mesofauna using a xylem and phloem stem‐injection technique on Sitka spruce (Picea sitchensis)
Authors: Churchland Carolyn , Weatherall Andrew , Briones Maria J. I. , Grayston Sue J.
Published: September 2012

RATIONALE

Here we report on the successful application of a novel stem‐injection stable‐isotope‐labeling and probing technique in mature trees to trace the spatial and temporal distribution of rhizosphere carbon belowground.

METHODS

Three 22‐year‐old Sitka spruce trees were injected with 6.66 g of 13C‐labeled aspartic acid. Over the succeeding 30 days, soil CO2 efflux, phospholipid fatty‐acid (PLFA) microbial biomarkers and soil invertebrates (mites, collembolans and enchytraeids) were analyzed along a 50 m transect from each tree to determine the temporal and spatial patterns in the translocation of recently fixed photosynthates belowground.

RESULTS

Soil δ13CO2 values peaked 13–23 days after injection, up to 5 m from the base of the injected tree and was, on average, 3.5‰ enriched in 13C relative to the baseline. Fungal PLFA biomarkers peaked 2–4 days after stem‐injection, up to 20 m from the base of the injected tree and were 13C‐enriched by up to 50‰. Significant 13C enrichment in mites and enchytraeids occurred 4–6 days after injection (by, on average, 1.5‰).

CONCLUSIONS

Stem injection of large trees with 13C‐enriched compounds is a successful tool to trace C‐translocation belowground. In particular, the significant 13C enrichment of CO2 and enchytraeids near the base of the tree and the significant 13C enrichment of PLFAs up to 20 m away indicate that mature Sitka spruce (Picea sitchensis) have the capacity to support soil communities over large distances. Copyright © 2012 John Wiley & Sons, Ltd.
Investigation of the ionization mechanism of polycyclic aromatic hydrocarbons using an ethanol/bromobenzene/chlorobenzene/anisole mixture as a dopant in liquid chromatography/atmospheric pressure photoionization mass spectrometry
Authors: Amad Ma'an , Sioud Salim
Published: September 2012

RATIONALE

An ethanol‐based multicomponent dopant consisting of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v/v/v) has been used as a dopant for atmospheric pressure photoionization (APPI) of polycyclic aromatic hydrocarbons (PAHs). In this study the mechanism of ionization of PAHs assisted by the ethanol‐based multicomponent dopant is investigated.

METHODS

The reactant background cluster ions of the ethanol‐based multicomponent dopant observed in the positive ion APPI were studied. These studies were performed to investigate the mechanism behind the generation of a molecular radical cation (M+•) for PAHs by APPI assisted by the ethanol‐based multicomponent dopant. Full scan and MS/MS analyses were conducted using an LTQ Orbitrap mass spectrometer. The effect of acidification of the mobile phase on the dopant cluster ion formation was also investigated.

RESULTS

With the ethanol‐based multicomponent dopant, a single type of molecular radical cation M+• was observed for the studied PAHs. The characteristic ion signal of the multicomponent dopant mixture consisted of mainly anisole photoions at m/z 108.05697 and its adduct ions at m/z 124.05188 and 164.07061. The anisole ion response at m/z 108.05697 was stable in the presence of acetonitrile, methanol, water and 0.1% formic acid mobile phase composition.

CONCLUSIONS

The abundance formation of anisole photoions shows the universality of this multicomponent dopant in ionizing compounds with ionization energy ranging from 7.1–8.2 eV. Since the ionization energy of anisole is 8.2 eV and is lower than those of chlorobenzene (9.07 eV) and bromobenzene (9.0 eV), the mechanism of formation of anisole photoions even with its very minute amounts was not only governed by its photoionization by the krypton lamp photon energy (10.0 eV and 10.6 eV), but also by charge transfer from bromobenzene and chlorobenzene radical cations. PAH molecules were mainly ionized by charge transfer reaction from photoionized anisole and oxidized anisole radical cations as well as by the krypton lamp. Copyright © 2012 John Wiley & Sons, Ltd.
Nonintrusive tracing in the Internet
Authors: Olteanu Alina , Xiao Yang , Liu Jing , Chen Thomas M. , Chen C. L. Philip
Published: September 2012

Intruders that log in through a series of machines when conducting an attack are hard to trace because of the complex architecture of the Internet. The thumbprinting method provides an efficient way of tracing such intruders by determining whether two connections are part of the same connection chain. Because many connections are transient and therefore short in length, choosing the best time interval to thumbprint over can be an issue. In this paper, we provide a way to shorten the time interval used for thumbprinting. We then study some special properties of the thumbprinting function. We also study another mechanism for tracing intruders in the Internet based on a timestamping approach, which passively monitors flows between source and destination pairs. Given a potentially suspicious source, we identify its true destination. We compute the error probability of our algorithm and show that its value decreases exponentially as the observation time increases. Our simulation results show that our approach performs well. Copyright © 2012 John Wiley & Sons, Ltd.
Compression‐based spam filter
Authors: Almeida Tiago A. , Yamakami Akebo
Published: September 2012

Nowadays, e‐mail spam is not a novelty, but it is still an important problem with a high impact on the economy. Spam filtering poses a special problem in text categorization, in which the defining characteristic is that filters face an active adversary, which constantly attempts to evade filtering. In this paper, we present a novel approach to spam filtering based on a compression‐based model. We have conducted an empirical experiment on eight public and real non‐encoded datasets. The results indicate that the proposed filter is fast to construct, is incrementally updateable, and clearly outperforms established spam classifiers. Copyright © 2012 John Wiley & Sons, Ltd.
A classic case of non‐diagnosis: erectile dysfunction following colorectal surgery
Authors: Dowswell George , Ismail Tariq , Greenfield Sheila , Clifford Sue , Wilson Sue
Published: September 2012

The prevalence of erectile dysfunction following colorectal cancer treatment is 75 per cent. Most men do not seek (and are not offered) help. Clinical care pre‐ and post‐treatment could be improved in several simple ways to ensure that men are better informed, more engaged and experience more positive outcomes. More tailored and co‐ordinated care is needed. Copyright © 2012 John Wiley & Sons
Rabies: an acute viral infection
Authors: Brightman Christopher
Published: September 2012

Rabies is a viral disease that causes acute encephalitis and is usually transmitted to humans by a bite from an infected animal. It is almost invariably fatal if postexposure prophylaxis is not administered before the onset of severe symptoms. Copyright © 2012 John Wiley & Sons
Hot topics for debate in prostate cancer: part 2
Authors: Payne Heather A. , Dearnaley David , Clarke Noel
Published: September 2012

This report is based on a seminar held during the 8th Annual Meeting of the British Uro‐oncology Group in York last September. Hot topics for debate covered in part 2 of this article are: ‘When and how to treat pelvic lymph nodes’ and ‘The significance of PSA in asymptomatic metastatic prostate cancer’. All participants, most of whom were clinical oncologists, were invited to contribute and respond to set questions using a keypad voting system. Copyright © 2012 John Wiley & Sons
Effect of 17‐alpha hydroxyprogesterone caproate on cervical length in twin pregnancies
Authors: Lim A. C. , Schuit E. , Papatsonis D. , van Eyck J. , Porath M. M. , van Oirschot C. M. , Hummel P. , Hasaart T. H. M. , Kleiverda G. , de Graaf I. M. , van Ginkel A. A. , Mol B. W. J. , Bruinse H. W.
Published: September 2012

Objectives

Previous studies on singleton pregnancies have indicated that progestogens may reduce the rate of cervical shortening during pregnancy. The aim of this study was to investigate whether treatment with 17‐alpha hydroxyprogesterone caproate (17‐OHPC) has an effect on cervical shortening in twin pregnancies.

Methods

This was a secondary analysis of patients who had participated in a multicenter randomized clinical trial on the effectiveness of 17‐OHPC in preventing preterm birth in multiple pregnancies (the AMPHIA‐trial). We included all trial participants with a twin gestation who had undergone repeat cervical length measurements during pregnancy. We performed a separate analysis of women with repeat measurements in centers where this was standard protocol for multiple pregnancies. The rate of cervical shortening for both the 17‐OHPC group and the placebo group was analyzed using a linear mixed model.

Results

Of the 671 patients who participated in the trial, 282 (42%) had a twin pregnancy and underwent two or more cervical length measurements. Of these women, 140 were monitored in centers where repeat measurements were standard protocol. We observed an overall reduction of cervical length from 44.3 mm at 14–18 weeks to 30.0 mm at 30–34 weeks' gestation. In the 17‐OHPC group, cervical length decreased by 1.04 mm each gestational week, while this was 1.11 mm per week for the placebo group (P = 0.6). For the overall group, each 10% decrease in cervical length led to an increase in the risk of preterm birth (hazard ratio, 1.14; 95% CI, 1.08–1.21).

Conclusion

In women with a twin pregnancy, there is progressive shortening of the cervix during pregnancy, regardless of 17‐OHPC use. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Automated systematic nomenclature generation for organic compounds
Authors: Williams Antony John , Yerin Andrey
Published: September 2012

The availability of systematic chemical names allows for the simple textual exchange of chemical structure information encoded into a name. The exchange of molecular structures in graphical format, molecular connection tables, or text strings encoding the molecule (e.g., SMILES and InChIs) is well established in cheminformatics and a plethora of chemical structure drawing tools exist to facilitate this exchange. However, even with well‐established systematic naming rules, software tools to allow for the generation of chemical names from structural inputs, and the reversal of these systematic names back to the original chemical structure, have only been available for a short time relative to the rules themselves. Although early tools were lacking in both capability and quality, they have matured over the years to provide excellent tools for chemists. Here, we review the capabilities of existing systematic naming software algorithms and tools and review some of the challenges, limitations, and future challenges for development. © 2012 John Wiley & Sons, Ltd.

This article is categorized under:

Computer and Information Science > Chemoinformatics
Regional credit market for species conservation: Developing the Fort Hood Recovery Credit System
Authors: Wolfe David W. , Brian Hays K. , Farrell Shannon L. , Baggett Susan
Published: September 2012

In 2005, Fort Hood Military Reservation (Fort Hood, TX, USA) staff sought assistance from the Texas Department of Agriculture and several partner organizations to develop a mitigation approach that included the ability to mitigate temporary impacts to habitat through temporary mitigation agreements with private landowners. Fort Hood, which is home to the largest known population of the federally endangered golden‐cheeked warbler (Setophaga chrysoparia; warbler), was at that time facing increased demands for military training activities that had the potential to disturb, but not likely destroy warbler habitat. Texas Department of Agriculture assembled an advisory committee and 3 stakeholder committees (science, economics, and policy), and tasked them with developing a cost‐efficient system that provided the desired mitigation, while also contributing to the recovery of the warbler. The resulting Recovery Credit System (RCS) enabled Fort Hood to purchase both permanent and temporary credits that represent habitat conservation actions from private landowners for use to mitigate impacts on the installation. We describe our experiences developing and implementing the RCS and briefly discuss new regional credit markets now underway or in development in Utah, USA, for the Utah prairie dog (Cynomys parvidens); in Texas for the dunes sagebrush lizard (Sceloporus arenicolus), golden‐cheeked warbler, black‐capped vireo (Vireo atricapilla), and lesser prairie chicken (Tympanuchus pallidicinctus); and in Colorado, USA, for the greater sage grouse (Centrocercus urophasianus). © 2012 The Wildlife Society.