bluuebunny/crossref_metadata_2025 huggingface dataset:
Maternal smoking and fetal lung volume—an in utero MRI investigation
Authors: Schmid Maximilian , Kasprian Gregor , Marschalek Julian , Posch Angela , Balassy Csilla , Prayer Daniela
Published: February 2011

Objective

To investigate whether fetal lung volume and fetal lung volume growth over gestation are different in mothers who reported smoking during pregnancy compared to non‐smoking controls.

Method

Cross‐sectional retrospective study of the data of 200 consecutive singleton pregnancies that underwent magnetic resonance imaging (MRI). Fetal lung volumes of 32 fetuses of mothers who reported smoking during pregnancy were compared to 168 fetuses of non‐smoking controls.

Results

Cases reported smoking between 2 and 30 cigarettes per day. The mean number of cigarettes per day for cases was 10.2 ± 6.1. After logarithmic transformation, lung volumes showed a linear increase with gestational age (r2 = 0.7). Multiple regression analysis revealed a significant influence of gestational age (p < 0.0001) but not maternal smoking status (p = 1.0) on fetal lung volumes. Comparison of the relative difference between observed and predicted lung volumes for both groups by means of unpaired t‐test revealed no significant influence of maternal smoking status on this variable (p = 0.9).

Conclusions

Fetuses of mothers who reported smoking during pregnancy show similar lung volumes and lung volume growth in MRI compared to non‐smoking controls. Our data suggest that a reduced lung volume is not responsible for the increase in respiratory symptoms associated with prenatal smoking. Copyright © 2011 John Wiley & Sons, Ltd.
Photovoltaics literature survey (no. 84)
Authors: Shrestha Santosh
Published: February 2011

In order to help keep readers up‐to‐date in the field, each issue of Progress in Photovoltaics will contain a list of recently published journal articles most relevant to its aims and scope. This list is drawn from an extremely wide range of journals, including IEEE Transactions on Electron Devices, Journal of Applied Physics, Applied Physics Letters, Progress in Photovoltaics and Solar Energy Materials and Solar Cells. To assist the reader, the list is separated into broad categories, but please note that these classifications are by no means strict. Also note that inclusion in the list is not an endorsement of a paper's quality. If you have any suggestions please e‐mail Santosh Shrestha at s.shrestha@unsw.edu.au. Copyright © 2011 John Wiley & Sons, Ltd.
Family disruption and academic functioning in urban, black youth
Authors: Somers Cheryl L. , Chiodo Lisa M. , Yoon Jina , Ratner Hilary , Barton Elizabeth , Delaney‐Black Virginia
Published: February 2011

The purpose of this study was to examine from an ecological perspective the relationships between multiple levels of family disruption and children's academic functioning in a sample of 390 urban, Black adolescents at age 14. Subjects in this cohort have been followed longitudinally since before their birth. Data from previous assessments at birth and age 7 years allowed for control of important correlates in this analyses. Examination of this unique sample, using multisource data collection procedures, provides important information about the many family disruptions among urban, low‐income families and the effects of these disruptions on academic outcomes. Results revealed several consistent findings, the most notable of which is that, when parents were married, adolescents demonstrated significantly higher grades, mediated through paternal involvement. Of all variables studied, the role of fathers in the lives of these adolescents was the most influential on academic outcomes. In this unique sample, even variables such as involvement with child protective services were not significantly related to outcomes after important control variables were factored into analyses. Results of this study have important implications for future research and for prevention and intervention efforts in urban, at‐risk samples. Emphasis is made for work in the school context, particularly for school psychologists. © 2011 Wiley Periodicals, Inc.
Closing the gap in school mental health: A community‐centered model for school psychology
Authors: Splett Joni Williams , Maras Melissa A.
Published: February 2011

Disciplines involved in the development and/or provision of services in school mental health have recognized the promise of evidence‐based practices in meeting the growing unmet mental health needs of children, adolescents, and families in this country. As a result, School Psychology has strongly emphasized the development and dissemination of evidence‐based practices through professional development opportunities and published literature. Despite these efforts, evidence‐based practices are not implemented as widely or as effectively as intended. This article describes a community‐centered (CC) model for closing the research‐to‐practice gap in school mental health. CC models emphasize both adopting new practices successfully and improving existing practices through a process of planning, implementation, and evaluation, and an exemplar framework based in a CC model is presented and applied to school mental health. The role of school psychologists in leading schools to adopt CC models is discussed, and next steps for changes to training, practice, and research paradigms are presented. © 2011 Wiley Periodicals, Inc.
Time to articulate a vision for the future of plant proteomics – A global perspective: An initiative for establishing the International Plant Proteomics Organization (INPPO)
Authors: Agrawal Ganesh Kumar , Job Dominique , Zivy Michel , Agrawal Vishwanath P. , Bradshaw Ralph A. , Dunn Michael J. , Haynes Paul A. , van Wijk Klaas J. , Kikuchi Shoshi , Renaut Jenny , Weckwerth Wolfram , Rakwal Randeep
Published: February 2011

Given the essential role of proteomics in understanding the biology of plants, we are establishing a global plant proteomics organization to properly organize, preserve and disseminate collected information on plant proteomics. We call this organization ‘International Plant Proteomics Organization (INPPO; http://www.inppo.com).’ Ten initiatives of INPPO are outlined along with how to address them in multiple phases. As our vision is global, we sincerely hope the scientific communities around the world will come together to support and join INPPO.
Low‐SDS Blue native PAGE
Authors: Klodmann Jennifer , Lewejohann Dagmar , Braun Hans‐Peter
Published: February 2011

SDS normally is strictly avoided during Blue native (BN) PAGE because it leads to disassembly of protein complexes and unfolding of proteins. Here, we report a modified BN‐PAGE procedure, which is based on low‐SDS treatment of biological samples prior to native gel electrophoresis. Using mitochondrial OXPHOS complexes from Arabidopsis as a model system, low SDS concentrations are shown to partially dissect protein complexes in a very defined and reproducible way. If combined with 2‐D BN/SDS‐PAGE, generated subcomplexes and their subunits can be systematically investigated, allowing insights into the internal architecture of protein complexes. Furthermore, a 3‐D BN/low‐SDS BN/SDS‐PAGE system is introduced to facilitate structural analysis of individual protein complexes without their previous purification.
Simplified enrichment of plasma membrane proteins for proteomic analyses in Arabidopsis thaliana
Authors: Zhang Zhe Jenny , Peck Scott C.
Published: February 2011

The plasma membrane (PM) serves as the point of contact between cells and the outside environment. As such, changes in the PM proteome are an important component of understanding cellular responses to a diverse array of stimuli. However, intricate sample handling to enrich PM proteomes by traditional methods is both technically challenging and time consuming. Here, we describe a simplified method for decreasing the representation of other membrane‐containing organelles such as the endoplasmic reticulum, plastids and mitochondria from crude microsomal membrane isolations. The decrease in other organellar proteomes results in an increase in both the total number of PM proteins and the number of spectra identified from these proteins representing the PM proteome. Therefore, this strategy represents a simple and rapid method for enriching PM proteins from Arabidopsis cell cultures for proteomic analyses.
Novel electroactive poly(arylene ether sulfone) copolymers containing pendant oligoaniline groups: Synthesis and properties
Authors: Chao Danming , Jia Xiaoteng , Liu Hongtao , He Libing , Cui Lili , Wang Ce , Berda Erik B.
Published: February 2011

We present a series of novel poly(arylene ether sulfone) copolymers containing pendant oligoaniline groups. A novel monomer containing oligoaniline, 2,6‐difluorobenzoyl aniline tetramer (DFAT), was synthesized by reaction of 2,6‐difluorobenzoyl chloride and parent aniline tetramer and incorporated into the aforementioned copolymers via direct copolymerization with 4,4′‐dichlorodiphenyl sulfone (DCDPS), and 4,4′‐isopropylidene diphenol (BPA) using N,N′‐dimethylacetamide as solvent. The structures of these copolymers were confirmed by FTIR, 1H NMR, and GPC. Spectral analysis of the copolymers in different oxidation states was investigated via UV‐visible spectra. The copolymers exhibited outstanding thermal stability and good solubility in various organic solvents. Their electroactivity, explored with cyclic voltammetry, was found to increase as the content of oligoaniline in the polymer increased. The electric and dielectric properties of the copolymers were also studied in detail. The electrochromic performance of the copolymers was investigated by electrochromic photographs and transmittance spectra; the color of the copolymer thin films changes from grey (at 0.0 V), to green (at 0.4 V), to blue (at 0.6 V) and to pearl blue (at 1.0 V) and the maximum transmittance change (ΔT) at 700 nm is 42.6% (90.7% ↔ 48.1%). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and characterization of polystyrene‐graphite nanocomposites via surface RAFT‐mediated miniemulsion polymerization
Authors: Etmimi Hussein M. , Tonge Matthew P. , Sanderson Ronald D.
Published: February 2011

Graphite oxide (GO) was prepared and immobilized with dodecyl isobutyric acid trithiocarbonate (DIBTC) reversible addition‐fragmentation chain transfer (RAFT) agent. The hydroxyl groups of GO were attached to the DIBTC RAFT agent through an esterification process. The resultant modified GO was used for the preparation of polystyrene (PS)/graphite nanocomposites in miniemulsion polymerization. The RAFT‐grafted GO (GO‐DIBTC) at various loadings was dispersed in styrene monomer, and the resultant mixtures were sonicated in the presence of a surfactant (sodium dodecylbenzene sulfonate) and a hydrophobe (hexadecane) to form miniemulsions. The stable miniemulsions thus obtained were polymerized using azobisisobutyronitrile as the initiator to yield encapsulated PS‐GO nanocomposites. The molar mass and polydispersity index of PS in the nanocomposites depended on the amount of RAFT‐grafted GO in the system, in accordance with the features of the RAFT polymerization method. The PS‐GO nanocomposites were of exfoliated morphology, as confirmed by X‐ray diffraction and transmission electron microscopy measurements. The thermal stability and mechanical properties of the PS‐GO nanocomposites were better than those of the neat PS polymer. Furthermore, the mechanical properties were dependent on the modified GO content (i.e., the amount of RAFT‐grafted GO). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Conversion of poly(ethylene‐alt‐tetrafluoroethylene) copolymers into polytetrafluoroethylene by direct fluorination: A convenient approach to access new properties at the ETFE surface
Authors: Calleja Gérard , Houdayer Axel , Etienne‐calas Sylvie , Bourgogne David , Flaud Valérie , Silly Gilles , Shibahara Sota , Takahara Atsushi , Jourdan Alex , Hamwi André , Ameduri Bruno
Published: February 2011

Direct fluorination of poly(ethylene‐alt‐tetrafluoroethylene) copolymer (ETFE) was carried out on commercially available ETFE films with pure fluorine gas at ambient atmosphere. Reaction temperature was either 95 °C or 150 °C and exposure time was 20 hours. Analysis of the fluorinated samples was performed by attenuated total reflection Fourier transform Infrared, confocal micro‐Raman and 1H and 19F magic angle spinning nuclear magnetic resonance spectroscopies, scanning electron microscopy, electron diffraction and X‐Ray photoelectron spectroscopies, contact angle determination, atomic force microscopy and nanoindentation measurements, and compared to those of the virgin ETFE copolymer. Integrity of the bulk materials was verified by investigating the thermal behavior of the polymers by thermogravimetric analysis and differential scanning calorimetry. Evidence for the formation of a homogeneous layer of polytetrafluoroethylene with a thickness of several microns at the surface of the copolymers with no degradation of the materials was observed. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis of poly(p‐phenylene)‐poly(4‐diphenylaminostyrene) bipolar block copolymers with a well‐controlled and defined polymer chain structure
Authors: Natori Itaru , Natori Shizue , Sekikawa Hiroyuki , Tsuchiya Kosuke , Ogino Kenji
Published: February 2011

A poly(p‐phenylene) (PPP)‐poly(4‐diphenylaminostyrene) (PDAS) bipolar block copolymer was synthesized for the first time. A prerequisite prepolymer, poly(1,3‐cyclohexadiene) (PCHD)‐PDAS binary block copolymer, in which the PCHD block consisted solely of 1,4‐cyclohexadiene (1,4‐CHD) units, was synthesized by living anionic block copolymerization of 1,3‐cyclohexadiene and 4‐diphenylaminostyrene. To obtain the PPP‐PDAS bipolar block copolymer, the dehydrogenation of this prepolymer with quinones was examined, and tetrachloro‐1,2‐(o)‐benzoquinone was found to be an appropriate dehydrogenation reagent. This dehydrogenation reaction was remarkably accelerated by ultrasonic irradiation, effectively yielding the target PPP‐PDAS bipolar block copolymer. The hole and electron drift mobilities for PPP‐PDAS bipolar block copolymer were both on the order of 10−3 to 10−4 cm2/V·s, with a negative slope when plotted against the square root of the applied field. Therefore, this bipolar block copolymer was found to act as a bipolar semi‐conducting copolymer. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Induction and inversion of chirality in poly‐L‐lysine and methyl orange complex
Authors: Takahashi Daisuke , Tanabe Ryoichi , Izumi Tsuyoshi
Published: February 2011

The mechanism of complexation of poly‐L‐lysine (PLL) with methyl orange (MO) and the appearance of induced circular dichroism (ICD) were investigated as a function of dye concentration and temperature and compared with that of the PLL‐ethyl orange complex. The formation of stoichiometric complexes with uniform size and intensities of ICDs depended on the length of alkyl groups (methyl and ethyl) as determined from quartz crystal microbalance measurement, absorption spectra, and CD spectra data. Furthermore, at constant PLL concentration, a dependence of the inversion of the ICD on the MO concentration (CMO) was observed in the PLL‐MO complexes, which to our knowledge has not been reported for a constant dye concentration system. The positive ICD in the PLL‐MO complexes observed at CMO lower than 2.0 × 10−5 M showed reversible changes in response to heating and cooling, whereas the negative ICD in PLL‐MO complexes observed at higher CMO inverted to positive ICD values in response to a decrease in temperature. These results demonstrate the alkyl group substituent in the dye, dye concentration, and temperature play important roles in the formation of PLL‐azo dye complex and ICD appearance. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Poly(siloxane‐urethane) crosslinked structures obtained by sol‐gel technique
Authors: Alexandru Mihaela , Cazacu Maria , Cristea Mariana , Nistor Alexandra , Grigoras Cristian , Simionescu Bogdan C.
Published: February 2011

Poly(siloxane‐urethane) crosslinked structures were prepared from isophorone diisocyanate, α,ω‐bis(hydroxybutyl)oligodimethylsiloxane and a new hybrid diol containing hydrolysable SiOC2H5 groups besides OH groups. The latest was synthesized by the acid‐catalyzed reaction between 1,3‐bis(3‐glycidoxypropyl)tetramethyldisiloxane and 3‐aminopropyltriethoxysilane. The formations of the urethane groups along the polymer backbone as well as the formation of the silica domains were first confirmed by the presence of the specific bands in Fourier transform infrared spectra. The resulted materials were characterized using differential scanning calorimetry, thermogravimetric analysis and scanning electron microscopy. The results of the dynamic mechanical analysis (DMA) performed at various frequencies revealed shape memory capabilities for some of the obtained structures. The silica formed because of the hydrolysis‐condensation reactions proved to have reinforcing effect upon siloxane‐urethane structure also evidenced by DMA and increasing water vapor sorption capacity as was measured by dynamic vapor sorption. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
DNA hydrogels: New functional soft materials
Authors: Okay Oguz
Published: February 2011

Deoxyribonucleic acid (DNA) hydrogel is a network of crosslinked DNA strands swollen in aqueous solutions. The crosslinks may be physical or chemical, such as the hydrogen bonds or ethylene glycol units, respectively, connecting the strands belonging to different double‐helical DNA molecules. As DNA network strands in the hydrogels exhibit properties similar to those of the individual DNA molecules, such soft materials are a good candidate to make use of the characteristics of DNA such as coil‐globule transition, biocompatibility, selective binding, and molecular recognition. Physical DNA hydrogels with an elastic modulus in the order of megapascals can be prepared by subjecting semidilute aqueous solutions of DNA to successive heating–cooling cycles between below and above the melting temperature of DNA. Chemical DNA hydrogels can be prepared by connecting the amino groups on the nucleotide bases through covalent bonds to form a three‐dimensional DNA network in aqueous solutions. In this article, we summarize the preparation strategies of DNA hydrogels with a wide range of tunable properties. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Mechanisms of large actuation strain in dielectric elastomers
Authors: Koh Soo Jin Adrian , Li Tiefeng , Zhou Jinxiong , Zhao Xuanhe , Hong Wei , Zhu Jian , Suo Zhigang
Published: February 2011

Subject to a voltage, a dielectric elastomer (DE) deforms. Voltage‐induced strains of above 100% have been observed when DEs are prestretched, and for DEs of certain network structures. Understanding mechanisms of large actuation strains is an active area of research. We propose that the voltage‐stretch response of DEs may be modified by prestretch, or by using polymers with “short” chains. This modification results in suppression or elimination of electromechanical instability, leading to large actuation strains. We propose a method to select and design a DE, such that the actuation strain is maximized. The theoretical predictions agree well with existing experimental data. The theory may contribute to the development of DEs with exceptional performance. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Sulfur and carbon isotopes within atmospheric, surface and ground water, snow and ice as indicators of the origin of tabular ground ice in the Russian Arctic
Authors: Leibman M.O. , Kizyakov A.I. , Lein A. Yu. , Perednya D.D. , Savvichev A.S. , Vanshtein B.G.
Published: February 2011

Field sampling of tabular ground ice (TGI) was undertaken at a number of geological sections along the Russian Arctic coast. 34S in sulfate ion and 13C in organic matter were analysed in ground ice and enclosing deposits, and in reference samples from snowpacks, atmospheric precipitation, surface waters and glaciers. The scatter in the stable isotope data obtained indicates the heterogeneity of moisture sources for TGI formation. There is a notable difference in the sulfur and carbon isotopic structure between TGI and atmospheric and continental moisture. TGI and its enclosing deposits have a heavier isotopic composition of sulfur and carbon than buried snow and glacial ice. This is considered to be evidence of an essential contribution of marine moisture and sediments to TGI formation. Copyright © 2011 John Wiley & Sons, Ltd.
Lobe‐specific lineages of carcinogenesis in the transgenic adenocarcinoma of mouse prostate and their responses to chemopreventive selenium
Authors: Wang Lei , Zhang Jinhui , Zhang Yong , Nkhata Katai , Quealy Emily , Liao Joshua D. , Cleary Margot P. , Lü Junxuan
Published: February 2011

BACKGROUND

The transgenic adenocarcinoma of mouse prostate (TRAMP) model is by far the most practical transgenic model for preclinical prostate cancer chemoprevention studies. It is critical to characterize the prostate lobe‐specificity of lesion lineages to consolidate the advantages of this model and minimize its limitations for chemoprevention studies.

METHODS

We dissected dorsolateral (DLP), ventral (VP), and anterior prostate (AP) lobes, and macroscopic tumors from 90 male C57BL/6J TRAMP mice at 22–24 weeks of age (WOA) and analyzed lesions by histological, biochemical and proteomic approaches. To determine whether methylseleninic acid (MSeA) led to a deletion of initiated cells, we gave oral MSeA to TRAMP mice from 5 to 23 WOA or from 5 to 15 WOA and analyzed lesions at 23 WOA.

RESULTS

All tumors (n = 18) were T‐antigen(+), synaptophysin (SYP)(+), androgen‐receptor(−), and E‐cadherin(−) poorly differentiated neuroendocrine carcinomas (NE‐Ca). They were traceable most frequently to VP (66.7%) and rarely to DLP (11.1%) and AP (5.6%) with an estimated life‐time incidence of 1 out of 3 mice. In DLP, epithelial lesions ranged from mild‐to‐severe atypical hyperplasia, with T‐antigen(+), SYP(−), androgen‐receptor(+), and E‐cadherin(+). Proteomic profiling revealed many molecular differences between VP and DLP. In MSeA experiment, 6 out of 19 (31.5%) mice developed NE‐Ca in the control group, only 2 in each MSeA group of 17–18 mice (11.1–11.8%) bore a detectable NE‐Ca.

CONCLUSION

The C57BL/6J TRAMP mouse represents at least two lineages of prostate carcinogenesis. Chemoprevention studies should incorporate this knowledge for efficacy assessment and molecular target validations. Prostate 71:1429–1440, 2011. © 2011 Wiley‐Liss, Inc.
Metabolic syndrome is associated with high grade gleason score when prostate cancer is diagnosed on biopsy
Authors: De Nunzio Cosimo , Freedland Stephen J , Miano Roberto , Trucchi Alberto , Cantiani Andrea , Carluccini Alfonso , Tubaro Andrea
Published: February 2011

BACKGROUND

To evaluate the association between metabolic syndrome (MS) and prostate cancer diagnosis and grade in patients undergoing prostate biopsy.

METHODS

From 2009 onwards, a consecutive series of patients undergoing 12‐core prostate biopsy for PSA value ≥4 ng/ml and/or positive digital rectal examination (DRE) were prospectively enrolled. Body mass index (BMI), waist circumferences, and blood pressure were measured before the biopsy. Blood samples were tested for: PSA, fasting glucose, triglycerides, and cholesterol HDL. MS presence was defined according to Adult Treatment Panel III criteria.

RESULTS

One hundred ninety five patients were enrolled with a median age and PSA of 69 years and 5.6 ng/ml respectively. Median BMI was 27.6 kg/m2 with 64 patients (33%) being classified as obese (BMI ≥ 30 kg/m2). Eighty‐six patients (44%) had MS. Eighty‐three patients (43%) had cancer on biopsy; 37 (45%) with MS and 46 (55%) without (P = 0.48). PSA was independently associated with higher risk of cancer (OR 1.12/1 U PSA, P = 0.01). Out of 83 patients with prostate cancer, 42 (51%) had Gleason score 6 (12 (28.5%) presented a MS) and 41 (49%) a Gleason score ≥7 (25 (61%) presented a MS). The presence of MS was not associated with an increased risk prostate cancer (OR: 0.97, P = 0.94) but with an increased risk of Gleason ≥7 (OR: 3.82; P = 0.013).

CONCLUSIONS

In our single center study, MS is associated with an increased risk of high grade Gleason score when prostate cancer is diagnosed on biopsy. However, these results should be confirmed in a larger multicenter study. Prostate 71:1492–1498, 2011. © 2011 Wiley‐Liss, Inc.
Combined effect of nucleopolyhedrovirus and Microplitis pallidipes for the control of the beet armyworm, Spodoptera exigua
Authors: Jiang Jiexian , Zeng Aiping , Ji Xiangyun , Wan Nianfeng , Chen Xiaoqin
Published: February 2011

BACKGROUND: Nucleopolyhedrovirus (SeNPV) and Microplitis pallidipes are important biological control agents of Spodoptera exigua populations. The interactions between these agents and their combined effect on pest control were investigated in the laboratory and in commercial greenhouses.

RESULTS: Microplitis pallidipes searched for and deposited eggs in more healthy larvae than virus‐infected larvae 3 days after viral infection. Each female parasitoid that developed in a virus‐infected host oviposited in a virus‐infected host, or emerged from a cocoon carrying virus transmitted to 4.0, 7.6 or 2.4 healthy larvae respectively. Each female parasitoid exposed to a mixture of virus and 10% honey water solution transmitted the virus to 2.2 healthy larvae. In an experiment with cabbage growing in commercial greenhouses, the pest population reduction was greater by M. pallidipes carrying SeNPV (82.3–89.7% reduction) than by parasitoids without virus (59.5–62.4% reduction).

CONCLUSIONS: Control of S. exigua was greater with M. pallidipes plus SeNPV than with M. pallidipes alone. Microplitis pallidipes preferred healthy hosts to infected hosts. Parasitoids were able to complete their development in virus‐infected hosts before the hosts died from the virus infection. The parasitoid ovipositors contaminated with the virus could carry and transmit SeNPV. Copyright © 2011 Society of Chemical Industry
Composition of essential oil of Chinese Chenopodium ambrosioides and insecticidal activity against maize weevil, Sitophilus zeamais
Authors: Chu Sha Sha , Feng Hu Jin , Liu Zhi Long
Published: February 2011

BACKGROUND: In a screening programme for new agrochemicals from Chinese medicinal herbs, Chenopodium ambrosioides L. was found to possess strong fumigant activity against the maize weevil Sitophilus zeamais (Motsch.). Essential oil of C. ambrosioides was obtained by hydrodistillation, and the constituents were determined by GC‐MS analysis. The active compounds were isolated and identified by bioassay‐directed fractionation.

RESULTS: Five active compounds [(Z)‐ascaridole, 2‐carene, ρ‐cymene, isoascaridole and α‐terpinene] were isolated and identified from the essential oil from Chinese C. ambrosioides. The LC50 values (fumigation) of the crude essential oils and the active compound (Z)‐ascaridole against S. zeamais adults were 3.08 and 0.84 mg L−1 air respectively. The LD50 values (contact toxicity) of the crude essential oil and (Z)‐ascaridole against S. zeamais adults were 2.12 and 0.86 µg g−1 body weight respectively.

CONCLUSION: The findings suggested that the essential oil of Chenopodium ambrosioides and its main active constituent, (Z)‐ascaridole, may be explored as a natural potential fumigant. Copyright © 2011 Society of Chemical Industry
Characterization of antilytic peptide antibody: application for the detection of lytic‐based hybrid peptide in serum samples
Authors: Ohara Koji , Horibe Tomohisa , Kohno Masayuki , Kawakami Koji
Published: February 2011

We previously reported that a novel targeted drug termed hybrid epidermal growth factor receptor (EGFR)‐lytic peptide, made by chemical conjugation of targeted binding peptide and cell‐killing, lytic‐peptide components, has selective cytotoxic activity that allows it to discriminate between normal and cancer cells. In addition, in vivo analysis revealed that this hybrid peptide displays significant antitumor activity in a xenograft model of human breast and pancreatic cancer in mice. Here, we characterized antilytic peptide antibody, which was raised from rabbit serum using the antigen of lytic peptide conjugated with keyhole limpet hemocyanin. It was found that antilytic peptide antibody is specific to the lytic peptide as assessed by both ELISA and surface plasmon resonance analysis and can also bind to EGFR‐lytic peptide. Epitope mapping analysis using Biacore showed that two successive lysine regions in the lytic‐peptide sequence are significant for recognition by this antibody. In addition, it was shown that this antibody can detect lytic‐based hybrid peptide in serum samples from mouse blood and also in cultured breast cancer MDA‐MB‐231 cell samples by immunocytochemical staining experiments. It was found that the maximum concentrations of this peptide in serum were reached within 15–30 min of i.v. administration of EGFR‐lytic peptide to mice. These results indicate that this antibody will be a useful tool for the detection of lytic‐based peptides to investigate their in vivo stability and pharmacokinetics. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Structural and magnetic phenomena in ultrathin C/Co/C stacks prepared by DC magnetron sputtering
Authors: Zolotaryov A. , Bugayev Ye. , Samofalov V. , Devizenko O. , Zubarev E. , Martens S. , Albrecht O. , Görlitz D. , Nielsch K.
Published: February 2011

We study two C(5 nm)/Co/C(5 nm) multilayer stacks with cobalt layer thicknesses of 4 and 13 nm. Structural analysis of fabricated systems reveals corresponding cobalt layers to be in amorphous (nanocrystalline) and [0001]‐textured hcp‐phase. The magnetic measurements for both systems agree well with structural data. For the amorphous cobalt layer magnetic data reveal the absence of carbides, high saturation field of 1.6 × 104 Oe and vanishing inplane coercive field. We also show that strong inplane anisotropy can be introduced into the amorphous cobalt film by controlling the process parameters of DC‐magnetron sputtering. For the textured hcp‐cobalt film we have deduced the presence of randomly close‐packed (rcp) structure. We assume this defect‐rich cobalt hcp‐phase to be responsible for the detected elimination of the out‐of‐plane magnetic anisotropy in the corresponding multilayer sample.
Misfit stresses and relaxation mechanisms in a nanowire containing a coaxial cylindrical inclusion of finite height
Authors: Gutkin Mikhail Yu. , Kuzmin Konstantin V. , Sheinerman Alexander G.
Published: February 2011

A model is suggested that describes stress relaxation in a nanowire with a finite‐height cylindrical inclusion (quantum dot). The stress field created in the nanowire by such an inclusion is calculated. Two different mechanisms of stress relaxation in a nanowire with a cylindrical inclusion are proposed and analyzed. The first mechanism involves the formation of a prismatic misfit dislocation loop around the inclusion while the second mechanism suggests the formation of a penny‐shaped crack in the inclusion cross section. It is shown that both mechanisms of stress relaxation can be realized in wide ranges of the structural and geometric parameters of the nanowire and inclusion. It is also demonstrated that in most cases the formation of a dislocation loop is more preferable than the formation of a penny‐shape crack, although in some situations, crack generation becomes more preferable.
Theoretical study of ion doping and substrate effects in antiferroelectric thin films
Authors: Wesselinowa Julia M. , Apostolov A. T. , Trimper Steffen
Published: February 2011

Antiferroelectric (AFE) thin films are studied under the influence of doping ions and the presence of substrates. Both induce a strong changing of the polarization and lead to a shift of the phase transition temperature. These effects can be understood within the Ising model in a transverse field with additional four spin interaction. To that aim different exchange interactions between the doping ions and the host ions as well as between the AFE thin film and the substrate are assumed. Using a Green's function technique the microscopic spectrum of the elementary excitation is calculated. From here we find that the transition temperature and the polarization is strongly influenced by the magnitude and the kind of stress, tensile or compressive. The competition between surface and substrate effects is discussed.
Substrate induced bandgap in multilayer epitaxial graphene on the 4H‐SiC ($000{\bar {1}}$) surface
Authors: Chen Mohan , Sun Wenlu , Guo Guang‐Can , He Lixin
Published: February 2011

We have investigated the electronic structures of graphene layers epitaxially grown on the 4H‐SiC ($000{\bar {1}}$) surface up to six layers by using first‐principles methods. The graphene layers grown on an ideal SiC interface are found to be p doped, whereas, those grown on a C‐deficient SiC interface are found to be n doped. We discuss the interlayer screening effects from the positions of the Fermi levels of each layer in our simulation. Interestingly, we find that the substrate may induce small atomic distortions in the graphene layers which could open about a 10 meV band gap in each graphene layer.
Avalanche‐like electric‐field‐induced photocurrent gain in resonant tunneling hydrogenated nanocrystalline silicon system
Authors: Chen Jing , Lu Jia Jia , Zhang Rong , Liu Yong Sheng , Shen Wen Zhong
Published: February 2011

By introducing photogeneration into the rate equation of the two‐energy‐level system, we obtain the photocurrent gain effect theoretically in hydrogenated nanocrystalline silicon (nc‐Si:H) structure, which is consistent with the reported experimental data. To understand the carrier‐transport characteristics in such nanostructures, the time‐dependent distributions of the electric field and photocurrent inside nc‐Si:H structure at different absorption coefficients have been calculated. The result shows that the occurrence of photocurrent enhancement is accompanied by an avalanche‐like phenomenon of the electric field during its dynamic process to achieve equilibrium. Further investigation reveals that the physical nature behind this photocurrent gain lies in the existence of the resonant tunneling inside the nc‐Si:H structure.
Investigation of modified p‐n junctions in CSG solar cells
Authors: Lausch Dominik , Werner Martina , Naumann Volker , Schneider Jens , Hagendorf Christian
Published: February 2011

In this paper a method for studying p‐n junctions is described. Different electron and ion beam charactersiation methods are introduced to determine the p‐n‐junction position using two different examples from Crystalline Silicon on Glass (CSG) thin film technology. In a first example lateral and cross section electron beam induced current (EBIC) measurements revealed that oxygen rich columnar growth at textured substrates disturbs strongly the p‐n junction. In a second example diffusion from glass specimen is identified by TOF‐SIMS to influencing the electrical and structural characteristics of the thin Si layer are responsible for the modified p‐n junction. A model describing the formation of both defect structures is introduced. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of the crystal features of mc‐Si PV cells by laser beam induced current (LBIC)
Authors: Moralejo B. , Hortelano V. , González M. A. , Martínez O. , Jiménez J. , Ponce‐Alcántara S. , Parra V.
Published: February 2011

In this work we present LBIC measurements of a set of commercial multicrystalline silicon samples manufac‐tured by different suppliers. The LBIC measurements were obtained with a home‐made system, using several excitation wavelengths, equipped with an autofocus system, and controlling the reflected light. This system keeps constant the distance between the microscope objective and the sample, despite the bowing and the surface roughness characteristic of this type of samples. For the calculation of the Leff maps one needs to consider the distribution of the reflected light, which the maps usually show contrasts corresponding to the different grain orientations. The LBIC maps present networks of dark lines, corresponding to regions with high carrier capture rates. The dark line network does not necessarily match the grain boundaries (GB) revealed in the optical images, but many of them are intragarin defects. The trapping activity of the GB is known to depend on the GB angle. Usually, small angle GBs are decorated with defects that make them electrically active, while the large angles GBs are less decorated, and present a weak electrical activity. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dislocations and cracks at Vickers indentations in GaN and GaAs bulk crystals
Authors: Ratschinski I. , Leipner H. S. , Heyroth F. , Fränzel W. , Hammer R. , Jurisch M.
Published: February 2011

The (0001) surface of GaN single crystals and ($ \bar 1 \bar 1 \bar 1 $)‐oriented GaAs wafers have been deformed using a Vickers indenter with two different orientations at room temperature. Dislocations and cracks at the indentations were observed by means of scanning electron microscopy, cathodoluminescence, light microscopy and transmission electron microscopy. Between dislocations, cracks and the orientation of the indenter, geometrical relations could be found.

The GaN and GaAs samples were indented with loads in the range of 0.02 N to 4.90 N and 0.02 N to 1.00 N, respectively. In both materials, the dislocation rosettes correspond to the symmetry of the indented surface. In (0001) GaN, the crack system is predominantly determined by the symmetry and orientation of the indenter. In contrast, the crack formation in ($ \bar 1 \bar 1 \bar 1 $) GaAs is determined by the symmetry of the crystal and consists of different types of radial cracks with different probabilities. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Assessing the capabilities and limitations of cathodoluminescence microscopy to investigate the optical properties of individual nanostructures
Authors: Stowe David
Published: February 2011

Understanding the optical properties of individual semiconductor nanostructures is an important step in enabling novel optoelectronic components. The capabilities and limitations of cathodoluminescence microscopy in the scanning and scanning transmission electron microscope in correlating the physical and optical properties of quantum wells, wires and dots is evaluated. In particular the importance of specimen‐electron beam interactions and experimental conditions in maximising spatial resolution are discussed (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of low energy electron irradiation on optical properties of InGaN/GaN light emitting structures
Authors: Vergeles P. S. , Shmidt N. M. , Yakimov E. E. , Yakimov E. B.
Published: February 2011

The effect of low energy e‐beam irradiation on the InGaN related cathodoluminescence in the MQW InGaN/GaN LED structures with different number of quantum wells has been studied. It is shown that the e‐beam exposure leads to an increase of emission intensity and to a formation of new blue‐shifted emission bands. It is shown that the changes in the optical properties are determined by the excess carrier injection. The changes observed were associated with the local changes of InGaN content due to In and/or Ga diffusion stimulated by the excess carrier recombination (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Origin of the Parry arc
Authors: Westbrook C. D.
Published: February 2011

Laboratory experiments to determine the preferred orientation of free‐falling hexagonal prisms were performed at Reynolds numbers appropriate to falling ice crystals in the atmosphere. Hexagonal plates orient with their c axis vertical for aspect ratios < 0.9, whilst hexagonal columns fall with their c axis horizontal. A secondary alignment is also observed: regular hexagonal columns fall preferentially with two prism facets aligned vertically and not horizontally – the latter scenario was previously assumed to be responsible for the rare Parry arc. However, if the column is made scalene in its cross‐section, it can orient such that a pair of prism facets is horizontal. This finding indicates that the development of scalene crystals may be key to the production of certain ice‐crystal optical phenomena. Copyright © 2011 Royal Meteorological Society
GRADIENTS IN THE BIOPHYSICAL STRUCTURE OF URBAN RIVERS AND THEIR ASSOCIATION WITH RIVER CHANNEL ENGINEERING
Authors: Gurnell A. M. , Shuker L. , Lee M. , Boitsidis A. J.
Published: February 2011

Urban rivers are often engineered to increase flood conveyance and stabilize channel size and position. This paper analyses habitat surveys of 180 urban river stretches of differing engineering type from four river basins (river Tame, West Midlands, UK; tributaries of the lower river Thames, UK; river Botic, Prague, Czech Republic; river Emscher, North‐Rhine Westphalia, Germany). Kruskal–Wallis tests identify significant differences in extent and/or frequency of flow types, bank and bed physical habitats, and vegetation characteristics associated with different styles of engineering. Principal Components Analysis identifies four key environmental gradients in the data set: sediment supply and retention; extent and diversity of in‐channel vegetation and riparian trees; bed and bank sediment calibre; flow type energy and complexity. These gradients discriminate stretches of differing planform, cross section and reinforcement and are significantly correlated with indices of degree and type of bank and bed reinforcement, pollution and presence of alien nuisance plant species. The analytical results illustrate statistically significant associations between different styles and levels of engineering intervention and the number and nature of physical habitats present in urban rivers. The results provide a basis for filtering sites for potential remedial measures prior to site‐specific surveys and modelling, for comparing sites and for tracking trajectories of change at sites that are subject to changes in channel engineering. They provide evidence that river condition and degree of engineering are not inversely related in a simple linear way, and that engineering of urban river channels, in the form of mixed, patchy reinforcement can contribute a great deal to habitat diversity where other controls on flow heterogeneity are more difficult to manipulate. Copyright © 2011 John Wiley & Sons, Ltd.
Science achievement of English language learners in urban elementary schools: Fourth‐grade student achievement results from a professional development intervention
Authors: Santau Alexandra O. , Maerten‐Rivera Jaime L. , Huggins Anne Corinne
Published: February 2011

As part of a 5‐year professional development intervention aimed at improving science and literacy achievement of English language learning (ELL) students in urban elementary schools, this study examined fourth‐grade students' science achievement across a 3‐year (2005–2008) implementation of our professional development intervention consisting of curriculum units and teacher workshops. Analyses were conducted with 1,758 students at six schools that participated in the intervention. The results of this study reveal several central findings. First, students in the treatment group displayed a statistically significant increase in science achievement from pre‐ to posttest. Second, there was no statistically significant difference in achievement gains between students at English to Speakers of Other Languages (ESOL) Levels 1–4 and students who had exited from ESOL or never been in ESOL. Third, there was no significant difference in achievement gains based on the year of participation in the intervention. Finally, students in the treatment group scored substantially lower on National Assessment of Educational Progress (NAEP) and Trends in International Mathematics and Science Study (TIMSS) items than the norm group at the pretest, but higher than the norm group at posttest. These results indicate that ELL students' improved achievement on the science test was a result of effective inquiry‐based science instruction as promoted in the professional development intervention. © 2011 Wiley Periodicals, Inc. Sci Ed 95:771–793, 2011
Secure topology maintenance and events collection in WSNs
Authors: Conti Mauro , Di Pietro Roberto , Gabrielli Andrea , Mancini Luigi V.
Published: February 2011

Topology Maintenance Protocols (TMPs) are key for operating Wireless Sensor Networks (WSNs). Their adoption serves a few goals, such as, to save energy, to avoid collisions in communications and to have an adequate number of nodes monitoring the environment—by alternating duty cycles with sleep cycles on the sensor nodes. While effectiveness of TMPs protocols is widely addressed, security is an overlooked feature. Indeed, while different TMPs have been presented in the literature, few of them address the security issues. In particular, only recently a secure TMP protocol that does not require pair‐wise node confidentiality has been proposed: Sec‐TMP. The aim of Sec‐TMP is to enforce event delivery to the Base Station while providing a standard topology maintenance service to the WSN. In this paper, we provide a thorough assessment of our previous preliminary proposal of Sec‐TMP, with particular reference to its effectiveness and security. First, we investigate the energy consumption introduced by TMPs protocols. Second, we show that Sec‐TMP performs well without any assumption neither on the show‐up time of data‐collecting node, nor on their mobility model. In particular, we test Sec‐TMP against a realistic unpredictable data‐collecting mobility scenario, that also brings in new security issues. A thorough security analysis of the proposed solutions to these new issues is also provided. Finally, extensive simulations support the quality of Sec‐TMP as for effectiveness and security. Copyright © 2011 John Wiley & Sons, Ltd.
Protocol for ownership transfer across authorities: with the ability to assign transfer target
Authors: Yang Ming Hour , Hu Hung Yuan
Published: February 2011

Radio Frequency Identification (RFID) has been widely deployed for its high capabilities in simple computation, storage, long scan distance, and simultaneous reading. With the combination of mobile devices and readers in recent years, it has been transformed to mobile RFID providing wider services for its users and mobility for its readers. E‐commerce, for instance, has applied many of mobile RFID's deriving services, one of which is the transfer of a tagged item's ownership. To secure such transfer in a mobile RFID environment, we propose a new approach for ownership transfer across different authorities and prove it able to stand most threats for RFID and to prevent Denial of Service (DoS) attacks that derive from asynchrony. Another contribution in this paper is that we can assign transfer targets, which, except our scheme, can only be achieved by Yang et al.'s Cross Authority Ownership Transfer (CAOT) protocol. That scheme, however, involves heavy computation and is not suitable for lightweight tags, whereas this scheme is designed for lightweight tags and has been proved viable on low‐cost passive tags and has better performance than any known ownership transfer schemes. Copyright © 2011 John Wiley & Sons, Ltd.