bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental results of optically controlled parallel guide directional coupler at W‐band
Authors: Fickenscher Thomas
Published: January 2010

Optical control of the coupling characteristics of parallel guide directional couplers in image guide technology is investigated experimentally in suppression mode at W‐band. Compared with previous designs, the control range of coupling versus illumination intensity is significantly increased because of a symmetric layout of the active section in dark state. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 626–629, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25014
A low complexity solution for integrating video surveillance and RFID in remote scene monitoring
Authors: Tsang P. W. M. , Yung K. N. , So K. H. , Cheung K. W. K.
Published: January 2010

In this article we reported, for the first time, a low complexity Field Programmable Gate Array solution for integrating video surveillance into RFID units. The method is comprised of two major building blocks, namely a RFID transmitter operating at a maximum bandwidth of 250 kbps, and a near computation free image compression engine based on an enhanced Decomposed Adaptive Decimation scheme. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 775–779, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25017
Six‐port transceiver for 6–9 GHz ultrawideband systems
Authors: Serban Adriana , Östh Joakim , Owais  , Karlsson Magnus , Gong Shaofang , Haartsen Jaap , Karlsson Peter
Published: January 2010

An ultrawideband 6–9 GHz six‐port correlator is designed and manufactured.Based on this six‐port correlator, behavioral models, and true component circuit designs of a transceiver are developed to study the performance of the proposed direct conversion ultrawideband transceiver topology. A new six‐port modulator with controllable impedance terminations implemented with a field effect transistor in the linear operation region is presented. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 740–746, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25021
Impact of laterally asymmetric channel and gate stack architecture on device performance of surrounding gate MOSFETs
Authors: Kaur Harsupreet , Kabra Sneha , Haldar Subhasis , Gupta R. S.
Published: January 2010

A new device design laterally asymmetric channel gate stack (LACGAS) SGT is proposed, and its impact on device performance is examined. By using analytical modeling and numerical simulations, the novel features of this structure are studied, and it is demonstrated that LACGAS offers superior performance when compared with conventional devices. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 746–750, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25022
60 GHz SoC/SoP radio system for high data‐rate transmission
Authors: Eun K. C. , Lee J.J. , Jung D. Y. , Cho S. J. , Kim H. Y. , Song I. S. , Lee Y. C. , Chang W. I. , Oh I. Y. , Yoon K. S. , Kang S. H. , Park C. S.
Published: January 2010

We present the 60 GHz CMOS and system‐on‐package (SoP) research activities in Korea Advanced Institute of Science and Technology for high data‐rate and short‐range wireless communication. A low‐power single‐chip resonant frequency CMOS receiver for 60 GHz mobile terminals consists of four‐stage current reuse LNA, resistive mixer, Ka‐band low‐phase noise VCO, high‐suppression frequency doubler, and two‐stage current reuse drive amplifiers. The receiver conversion gain and input P1dB are −9.5 dB and −12.5 dBm, respectively, with a size of 2.67 × 0.75 mm2and power consumption of 21.9 mW. The integration and communication tests of a transmitter/receiver (Tx/Rx) radio have been demonstrated at a data rate of 3 Gbps for short‐range transmission and with a communication distance of over 3.5 m at 650 Mbps data rate. The design and fabrication of mmW subcircuits, such as low‐loss transmission lines and transitions with noble air cavity structures, a high‐Q resonator using zigzagged dual‐row via posts and a λ/4 short stub, and the monolithic integration of band‐pass filter and antennas, have been performed for low‐temperature cofired ceramic SoP integration with a size of 37 × 11 mm2for the whole Tx or Rx radio. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 667–673, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25024
A novel approach to reduce the near field electromagnetic scattering for designing HAC compatible mobile phones
Authors: Zhao Anping , Ollikainen Jani , Thaysen Jesper , Bodvarsson Thorvaldur
Published: January 2010

By splitting the upper printed wiring board (PWB) of a fold mobile phone into two parts and connected with an inductor, the near field electromagnetic scattering of mobile phones can be significantly reduced. In fact, the gap between the split PWB tends to act as a capacitor. Hence, the gap and the inductor form an LC band‐stop filter embedded in the PWB. With the help of this filter, the current flowing on the PWB can be constrained before it reaches the end of the PWB, which results in less electromagnetic field scattering in the hearing aid compatibility (HAC) region, and thus, leads to an HAC compatible mobile phone design. The design principle works well for fold phones with both one‐hinge and two‐hinge cases. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 709–715, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25026
A new assignment technique of 2D‐NMR spectra by spin‐lock sequence to a tripeptide containing tryptophan in water
Authors: Watanabe Eiji , Yamakura Fumiyuki , Kan Hirosaki
Published: January 2010

We developed a new assignment technique of tryptophan residues using pulsed field gradient TOCSY–ROESY (PFG‐TORO) and pulsed field gradient TOCSY–ROESY–TOCSY (PFG‐TOROTO) techniques in water. Connectivity from βH to ζ2H (H‐7) via ε1H (H‐1) and δ1H (H‐2) in the TORO spectrum and from βH to ζ3H (H‐5) and η2H (H‐6) via ε1H (H‐1) and δ1H (H‐2) in the TOROTO spectrum could be able to assign each of the protons of the indole rings. Copyright © 2010 John Wiley & Sons, Ltd.
Transgenic sperm produced by electrotransfection and allogeneic transplantation of chicken fetal spermatogonial stem cells
Authors: Yu Fei , Ding Li‐Jun , Sun Guo‐Bo , Sun Peng‐Xiang , He Xian‐Hong , Ni Li‐Gang , Li Bi‐Chun
Published: January 2010

To study self‐renewal, genetic modification, and differentiation of avian spermatogonial stem cells (SSCs), we isolated chicken SSCs from fetal testes on the 16th hatching day via enzyme digestion, and then cultured the SSCs over 2 months after purification in vitro. SSCs were identified by alkaline phosphatase staining and SSEA‐1 fluorescence. The EGFP gene was transfected into SSCs by three different methods: electroporation, liposome transfer and calcium acid phosphate precipitation. The transfection rate and cell survival rate using electroporation were higher than when using liposomes or calcium acid phosphate (20.52% vs. 9.75% and 5.61%; 69.86% vs. 65.00% and 51.16%, respectively). After selection with G418 for 8 days, the transgenic SSCs were transplanted into the testes of cocks treated with busulfan. Twenty‐five days after transplantation, the recipients' semen was light ivory in color, and the density of spermatozoa was 3.87 (×107/ml), with 4.25% expressing EGFP. By 85 days after transplantation, the number of spermatozoa increased to 32.7 (×107/ml) and the rate of EGFP expression was 16.25%. Frozen sections of the recipients' testes showed that transgenic SSCs were located on the basal membrane of the seminiferous tubules and differentiated into spermatogenic cells at different stages. The EGFP gene was successfully amplified from the DNA of all recipients' semen samples. Mol. Reprod. Dev. 77: 340–347, 2010. © 2010 Wiley‐Liss, Inc.
Preparation, swelling, and stimuli‐responsive characteristics of superabsorbent nanocomposites based on carboxymethyl cellulose and rectorite
Authors: Wang Wenbo , Wang Aiqin
Published: January 2010

Utilization of naturally available raw materials for the fabrication of eco‐friendly functional materials has long been desired. In this work, a series of superabsorbent nanocomposites were prepared by radical solution copolymerization of sodium carboxymethyl cellulose (CMC), partially neutralized acrylic acid (NaA), and rectorite (REC) in the presence of initiator ammonium persulfate (APS) and crosslinker N,N'‐methylene‐bis‐acrylamide (MBA). The optimal reaction variables including the mass ratio of acrylic acid (AA) to CMC, MBA concentration, and REC content were explored. FTIR spectra confirmed that NaA had been grafted onto CMC and REC participated in polymerization. REC was exfoliated and uniformly dispersed in the CMC‐g‐PNaA matrix without agglomeration as shown by XRD, TEM, and SEM analysis. The thermal stability, swelling capabilities, and rate of the nanocomposites were improved after introducing REC, and the gel strength greatly depended on the concentration of crosslinker MBA. The nanocomposite showed excellent responsive properties and reversible On–Off switching characteristics in various saline, pH, and hydrophilic organic solvent/water solutions, which provided great possibility to extend the application domain of the superabsorbent nanocomposites such as drug delivery system. Copyright © 2010 John Wiley & Sons, Ltd.
Influence of low multi‐walled carbon nanotubes loadings on the crystallization behavior of biodegradable poly(butylene succinate) nanocomposites
Authors: Song Liang , Qiu Zhaobin
Published: January 2010

Biodegradable poly(butylene succinate) (PBSU)/carboxyl‐functionalized multi‐walled carbon nanotubes (f‐MWNTs) nanocomposites were prepared via solution casting method at low f‐MWNTs loadings of 0.5 and 1 wt%, respectively, in this work. Scanning and transmission electron microscopic observations reveal a fine dispersion of f‐MWNTs throughout the PBSU matrix. Non‐isothermal melt crystallization at different cooling rates, isothermal melt crystallization at different crystallization temperatures, spherulitic morphology, and crystal structure of neat PBSU and its nanocomposites were investigated with various techniques in detail. The addition of f‐MWNTs is found to enhance the crystallization of PBSU, apparently in the nanocomposites during both nonisothermal and isothermal melt crystallization, due to the heterogeneous nucleation effect; however, the crystallization mechanism and crystal structure of PBSU remain almost unchanged. Effect of the presence of f‐MWNTs and their loadings on the thermodynamic driving force for nucleation and nucleation activity of PBSU was evaluated quantitatively through two methods. Moreover, it is found that incorporating with 1 wt% f‐MWNTs significantly improves the storage modulus of PBSU in the nanocomposites by about 147% at room temperature as compared with that of neat PBSU. Copyright © 2010 John Wiley & Sons, Ltd.
Oncogenic KRAS is not necessary for Wnt signalling activation in APC‐associated FAP adenomas
Authors: Obrador‐Hevia Antònia , Chin Suet‐Feung , González Sara , Rees Jonathan , Vilardell Felip , Greenson Joel K , Cordero David , Moreno Víctor , Caldas Carlos , Capellá Gabriel
Published: January 2010

Recent studies have suggested that APC loss alone may be insufficient to promote aberrant Wnt/β‐catenin signalling. Our aim was to comprehensively characterize Wnt signalling components in a set of APC‐associated familial adenomatous polyposis (FAP) tumours. Sixty adenomas from six FAP patients with known pathogenic APC mutations were included. Somatic APC and KRAS mutations, β‐catenin immunostaining, and qRT‐PCR of APC, MYC, AXIN2 and SFRP1 were analysed. Array‐comparative genomic hybridization (aCGH) was also assessed in 26 FAP adenomas and 24 paired adenoma–carcinoma samples. A somatic APC alteration was present in 15 adenomas (LOH in 11 and four point mutations). KRAS mutations were detected in 10% of the cases. APC mRNA was overexpressed in adenomas. MYC and AXIN2 were also overexpressed, with significant intra‐case heterogeneity. Increased cytoplasmic and/or nuclear β‐catenin staining was seen in 94% and 80% of the adenomas. β‐Catenin nuclear staining was strongly associated with MYC levels (p value 0.03) but not with KRAS mutations. Copy number aberrations were rare. However, the recurrent chromosome changes observed more frequently contained Wnt pathway genes (p value 0.012). Based on β‐catenin staining and Wnt pathway target genes alterations the Wnt pathway appears to be constitutively activated in all APC‐FAP tumours, with alterations occurring both upstream and downstream of APC. Wnt aberrations are present at both the DNA and the RNA level. Somatic profiling of APC‐FAP tumours provides new insights into the role of APC in tumourigenesis. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Delayed administration of filgrastim (G‐CSF) following autologous peripheral blood stem cell transplantation (APBSCT) in pediatric patients does not change time to neutrophil engraftment and reduces use of G‐CSF
Authors: Pai Vinita , Fernandez Soledad A. , Laudick Melissa , Rosselet Robin , Termuhlen Amanda
Published: January 2010

Background

Delayed initiation of granulocyte colony stimulating factor (G‐CSF) after high‐dose chemotherapy and autologous bone marrow or peripheral blood stem cell (APBSCT) in adult patients does not affect time to neutrophil or platelet engraftment, duration of fever, incidence of bacteremia, duration of non‐prophylactic antibiotic therapy, and length of hospitalization when compared to early initiation. This study compares the effect of delayed (day +6) versus early (day +1) administration of G‐CSF in pediatric patients on time to neutrophil engraftment (TNE), duration and cost of G‐CSF therapy, incidence of blood stream infections, duration of febrile–neutropenia, duration of non‐prophylactic antibiotic therapy, and duration of hospitalization due to febrile–neutropenia.

Methods

This is a retrospective review of 65 patients who engrafted after receiving APBSCT and G‐CSF between 1993 and 2006. They were divided into the delayed group (day +6) (n = 46) and the early group (day +1) (n = 19).

Results

The median ages were 4.7 and 5.3 years in the early and delayed groups, respectively. There was no significant difference in TNE (P = 0.06) between the two groups. The duration of G‐CSF administration was significantly less in the delayed group (P = 0.003). No significant differences were observed in the duration of neutropenia, time to platelet engraftment, the incidence of blood stream infections, and duration of fevers. Duration of hospitalization due to febrile–neutropenia was significantly lower in the delayed group (P = 0.01). Significant cost savings were observed by delaying G‐CSF administration.

Conclusion

Delayed administration of G‐CSF after APBSCT in children has no adverse effect on TNE or other clinical outcomes when compared to early administration and may incur substantial cost savings. Pediatr Blood Cancer 2010;54:728–733. © 2009 Wiley‐Liss, Inc.
Irinotecan as maintenance therapy in high‐risk hepatoblastoma
Authors: Qayed Muna , Powell Christie , Morgan Elaine R. , Haugen Maureen , Katzenstein Howard M.
Published: January 2010

Children with high‐risk hepatoblastoma (metastatic disease or a low alpha‐fetoprotein at presentation) and those with recurrent disease have an extremely poor prognosis and are in need of novel therapeutic agents and strategies. We describe three patients who were treated with irinotecan (two in combination with vincristine). In two patients, this contributed to a clinical remission. All three patients received a 1‐ to 2‐year course of irinotecan as maintenance therapy and all remain disease free. Treatment was well tolerated with minimal toxicity. Further evaluation of the use of irinotecan as maintenance therapy in high‐risk and recurrent HB patients is warranted. Pediatr Blood Cancer 2010;54:761–763. © 2009 Wiley‐Liss, Inc.
A feasibility trial of a video intervention to improve informed consent for parents of children with leukemia
Authors: Hazen Rebecca A. , Eder Michelle , Drotar Dennis , Zyzanski Steve , Reynolds Amy E. , Reynolds C. Patrick , Kodish Eric , Noll Robert B.
Published: January 2010

Background

Research on parental understanding of informed consent for pediatric randomized clinical trials (RCTs) has highlighted weaknesses in understanding of key aspects of informed consent. The goals of the current study were to assess the feasibility of and parental satisfaction with a video intervention to improve informed consent for pediatric leukemia RCTs and to compare parental question asking during informed consent conferences (ICCs) for parents in the current study with historical control data.

Procedure

A 20‐min video was produced. Utilizing the principles of anticipatory guidance, it included information delivered by nurses and physicians about leukemia and key aspects of informed consent. Parents were encouraged to be active participants in ICCs. Participants included 12 parents of children newly diagnosed with pediatric leukemia. The video was viewed by local pediatric oncologists prior to utilization with families.

Results

Ninety‐two percent of parents reported that the video made it easier to understand information that their child's physician later provided; 83% of parents reported that it helped them to think of questions to ask the physician; and 67% of parents indicated that the video made them feel more comfortable with asking questions of the physician. Results of a t‐test comparing question asking during ICCs revealed that parents who participated in the intervention asked a higher rate of questions than parents from a historical control sample (t = 1.95, P = 0.05).

Discussion

Our study supports the feasibility and potential efficacy of a brief video intervention employing anticipatory guidance to prepare parents for future discussions about RCTs. Pediatr Blood Cancer 2010;55:113–118. © 2010 Wiley‐Liss, Inc.
Comparing pediatric deaths with and without hospice support
Authors: Dickens David S.
Published: January 2010

Background

Although pediatric hospice care is commonly accepted as a beneficial intervention, the incremental advantage over end‐of‐life care delivered without engaging hospice remains unknown. The primary objective of this study was to describe differences in pediatric end‐of‐life care when delivered with and without hospice support, as perceived by the medical provider.

Procedure

A retrospective survey of medical providers was conducted in 2005 over a 2‐month period at a single institution, the Helen DeVos Children's Hospital (HDVCH). Medical providers with self‐determined experience in pediatric end‐of‐life care were asked to separately provide positive and negative comments about their experience with hospice. Additionally they were asked to describe differences between children under their supervision who died with and without hospice care. Medical provider comments and comparisons of experiences in caring for children dying with and without hospice involvement are described.

Results

Out of 157 responders, 43 reported positive comments about the hospice intervention. Non‐medical support and location of death were the most frequently cited benefits. Nineteen responders provided negative comments about hospice; all involving feelings of lost hope, intrusion, or distrust. When asked to directly compare deaths with and without hospice support, 44 of 51 (86%) responders favored hospice. The most cited reason for preferring hospice involvement was better provision of non‐medical services.

Conclusions

The majority of pediatric providers in this survey observed an advantage to utilizing hospice care for dying children as compared to providing end‐of‐life care without hospice involvement. Pediatr Blood Cancer 2010;54:746–750. © 2010 Wiley‐Liss, Inc.
Trends in prenatal screening and diagnostic testing among women referred for advanced maternal age
Authors: Nakata Naomi , Wang Yuemei , Bhatt Sucheta
Published: January 2010

Objective

We evaluated the trends in uptake of amniocentesis and chorionic villi sampling (CVS) for prenatal diagnosis compared with uptake of first and second trimester prenatal serum screening for Down syndrome among patients referred for genetic counseling for advanced maternal age (AMA).

Methods

Patients referred for AMA genetic counseling from 2001 through 2008 were informed of both prenatal serum screening and invasive diagnostic testing options. Testing offered and testing decisions were entered in a computer database and uptake rates calculated for each year with trends compared using logistic regression analysis.

Results

From 2001 through 2007, we observed a decline in amniocentesis and CVS uptake (p = 0.0001). This trend reversed in 2008 for both invasive procedures (p = 0.0001). Uptake of prenatal serum screening increased over the study period with uptake of first trimester screening increasing 1.7 fold in 2008.

Conclusion

Improved prenatal screening tests and increased availability of screening for AMA patients has led to a steady decline in uptake of invasive testing from 2001 through 2007. This trend reversed from 2007 through 2008. Possible reasons for this reversal are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Novel diol spiro orthocarbonates derived from glycerol as anti‐shrinkage additives for the cationic photopolymerization of epoxy monomers
Authors: Acosta Ortiz Ricardo , Duarte María Lydia Berlanga , Gómez Amy Grace Savage , Sangermano Marco , García Valdez Aída E
Published: January 2010

Shrinkage that takes place during polymerizations induces internal stress in polymeric materials generating a series of problems like poor adhesion to substrates and delamination in coatings or microcracks and microvoids in composites. Some additives like spiro orthocarbonates can reduce or eliminate this shrinkage. This paper deals with the synthesis of novel diol spiro orthocarbonates (DIOL SOCs) and their effect as anti‐shrinkage additives in the photopolymerization of the monomer 3,4‐epoxycyclohexyl‐3′, 4′‐epoxycyclohexanecarboxylate. It was found that increasing the concentration of the DIOL SOCs resulted in higher conversion of the monomer due to the presence of hydroxyl groups. The viscoelastic properties of the polymer products were also measured. It was observed that at 5 mol% of the mixture of DIOL SOCs there was an increase in the storage modulus due to the crosslinking produced by the bifunctional SOCs. However, at higher concentrations, a decrease in the storage modulus was observed. The level of shrinkage using the DIOL SOCs at 20 mol% was reduced by 45% when compared to the case without any additive. DIOL SOCs can be easily prepared by reacting glycerol with tetraethylorthocarbonate. These additives reduced significantly the level of shrinkage of the polyether derived from the diepoxycyclohexane monomer. Copyright © 2010 Society of Chemical Industry
A fluorescent chemosensor based on optically active 2,2′‐binaphtho‐20‐crown‐6 for metal ions
Authors: Miao Qian , Huang Hui , Huang Xiaobo , Xu Ying , Zong LiLi , Cheng Yixiang
Published: January 2010

A chiral conjugated polymer can be obtained by the polymerization of (S)‐6,6′‐dibromo‐2,2′‐binaphtho‐20‐crown‐6 and 1,4‐divinyl‐2,5‐dibutoxybenzene via a palladium‐catalyzed Heck cross‐coupling reaction. The chiral conjugated polymer shows strong green‐blue fluorescence. The responsive properties of the chiral polymer to metal ions were investigated using fluorescence and UV‐visible absorption spectra. K+, Pb2+, Cd2+and Ba2+enhance the fluorescence of the polymer; in contrast, Hg2+causes effective quenching of the fluorescence of the polymer. The obvious influences on the fluorescence indicate that the 2,2′‐binaphtho‐20‐crown‐6 moiety plays an important role in fluorescence recognition for Hg2+due to the effective photo‐induced electron transfer or charge transfer between the conjugated polymer backbone and the receptor ions. The responsive properties of the polymer to metal ions show that the chiral conjugated polymer incorporating 2,2′‐binaphtho‐20‐crown‐6 moieties in the main‐chain backbone as recognition sites can act as an excellent fluorescent probe for the sensitive detection of Hg2+. Copyright © 2010 Society of Chemical Industry
Rapid vacuolar sequestration: the horseweed glyphosate resistance mechanism
Authors: Ge Xia , d'Avignon D André , Ackerman Joseph JH , Sammons R Douglas
Published: January 2010

BACKGROUND: Glyphosate‐resistant (GR) weed species are now found with increasing frequency and threaten the critically important GR weed management system.

RESULTS: The reported 31P NMR experiments on glyphosate‐sensitive (S) and glyphosate‐resistant (R) horseweed, Conyza canadensis (L.) Cronq., show significantly more accumulation of glyphosate within the R biotype vacuole.

CONCLUSIONS: Selective sequestration of glyphosate into the vacuole confers the observed horseweed resistance to glyphosate. This observation represents the first clear evidence for the glyphosate resistance mechanism in C. canadensis. Copyright © 2010 Society of Chemical Industry
Diuretics: guide to properties and efficacy in hypertension
Authors: Girvin Briegeen , Johnston Dennis
Published: January 2010

Diuretics are as effective as newer treatments in hypertension and they still remain drugs of first choice. This Drug Review considers their mode of action and properties, followed by sources of further information and a review of prescription data. Copyright © 2009 Wiley Interface Ltd
Liraglutide: new GLP‐1 analogue for uncontrolled type 2 diabetes
Authors: Chaplin Steve , Ahmad Aftab
Published: January 2010

Liraglutide (Victoza) is a new GLP‐1 analogue given by once‐daily injection for the treatment of type 2 diabetes not controlled by mono‐ or dual therapy with oral agents. In our New products review, Steve Chaplin presents the clinical data relating to its efficacy and adverse effects, and Dr Aftab Ahmad considers its potential place in therapy. Copyright © 2009 Wiley Interface Ltd
Interaction of a β‐sheet breaker peptide with lipid membranes
Authors: Vitiello Giuseppe , Grimaldi Manuela , Ramunno Anna , Ortona Ornella , De Martino Giovanni , D'Ursi Anna Maria , D'Errico Gerardino
Published: January 2010

Aggregation of β‐amyloid peptides into senile plaques has been identified as one of the hallmarks of Alzheimer's disease. An attractive therapeutic strategy for Alzheimer's disease is the inhibition of the soluble β‐amyloid aggregation using synthetic β‐sheet breaker peptides that are capable of binding Aβ but are unable to become part of a β‐sheet structure. As the early stages of the Aβ aggregation process are supposed to occur close to the neuronal membrane, it is strategic to define the β‐sheet breaker peptide positioning with respect to lipid bilayers. In this work, we have focused on the interaction between the β‐sheet breaker peptide acetyl‐LPFFD‐amide, iAβ5p, and lipid membranes, studied by ESR spectroscopy, using either peptides alternatively labeled at the C‐ and at the N‐terminus or phospholipids spin‐labeled in different positions of the acyl chain. Our results show that iAβ5p interacts directly with membranes formed by the zwitterionic phospholipid dioleoyl phosphatidylcholine and this interaction is modulated by inclusion of cholesterol in the lipid bilayer formulation, in terms of both peptide partition coefficient and the solubilization site. In particular, cholesterol decreases the peptide partition coefficient between the membrane and the aqueous medium. Moreover, in the absence of cholesterol, iAβ5p is located between the outer part of the hydrophobic core and the external hydrophilic layer of the membrane, while in the presence of cholesterol it penetrates more deeply into the lipid bilayer. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Transformation of photoluminescence spectra at the bioconjugation of core‐shell CdSe/ZnS quantum dots
Authors: Macotela L. G. Vega , Douda J. , Torchynska T. V. , Sierra R. Peña , Shcherbyna L.
Published: January 2010

The photoluminescence (PL) of nonconjugated and bioconjugated core‐shell CdSe/ZnS quantum dots (QDs) has been discussed in this paper. Commercial CdSe/ZnS QDs with the size of 3.6‐4.0 nm covered by polymer with emission at 560‐565 nm (2.19‐2.22 eV) have been used. The QD bioconjugation is performed with the mouse anti PSA (Prostate‐Specific Antigen) antibody (mab). PL spectra of nonconjugated QDs are characterized by a superposition of PL bands related to exciton emission in the CdSe core (2.19‐2.22 eV) and to hot electron‐hole emission via surface states (2.37, 2.73 and 3.06 eV) at the CdSe/ZnS or ZnS/polymer interfaces. The PL spectrum of bioconjugated QDs has changed dramatically, with essential decreasing of the hot electron‐hole recombination flow via interface states. This effect is explained on the base of re‐charging of QD interface states at the bioconjugation. It is shown that the CdSe/ZnS QDs with interface states are very promising for the study of bioconjugation effects to antibodies (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of metal‐oxide‐semiconductor capacitors with r.f. magnetron sputtering TiOxNy films dielectric layer
Authors: Albertin Katia Franklin , Pereyra Inés
Published: January 2010

A set of MOS capacitors with TiOxNy films as gate dielectric layer was fabricated and characterized. The TiOxNy films were deposited by reactive r.f. magnetron sputtering varying the nitrogen and oxygen partial pressure in a Ar/N2/O2 gaseous mixture.

The TiOxNy films were characterized by, Rutherford Backscattering (RBS), X‐ray absorption near edge spectroscopy (XANES) in oxygen K‐edge (O‐K), optical absorption and High Resolution Transmission Electron Microscopy (HRTEM). Capacitance‐voltage (1MHz) and current‐voltage measurements were performed to obtain the effective dielectric constant, the effective oxide thickness (EOT), the leakage current density, and the interface quality. MOS capacitors results show that the TiOxNyfilms dielectric constant varies from 28 to 80, present a good interface quality with silicon, and the leakage current density values are in the order of 0.25 mA/cm2 for VG = –2V, which is acceptable for high performance logic circuits and low power circuits fabrication. The leakage current density is reduced in 2 orders of magnitude for increasing nitrogen concentration (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dominant ion species in VHF SiH4/H2 plasma
Authors: Yamauchi Yasuhiro , Baba Tomoyoshi , Yamane Tsukasa , Takeuchi Yoshiaki , Takatsuka Hiromu , Muta Hiroshi , Uchino Kiichiro , Kawai Yoshinobu
Published: January 2010

Dominant ion species in VHF SiH4/H2 plasma (frequency 60 MHz) were estimated from the sheath potential and the electron temperature measured with the Langmuir probe. As the concentration of SiH4/H2 was increased, the transition of dominant ion species from H+ to SiH3+ was observed. When the discharge gap was shorter than 10 mm, measured sheath potentials were anomalously low compared with the calculated ones (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoinduced volume changes in obliquely deposited a‐Se
Authors: Lukács R. , Kugler S.
Published: January 2010

The structures and the photoinduced volume changes of obliquely deposited amorphous selenium were studied using Molecular Dynamics computer simulation. Obliquely deposited a‐Se thin films contain larger voids than the flatly deposited ones. Our computer simulations confirmed that the preparation method strongly determines the photoinduced changes of the chalcogenide glasses. We described in detail for the first time the complex atomic rearrangements occurring on photo‐excitation in porous samples, which are reversible and irreversible photo contraction/expansion, bond breakings and formations (both inter‐ and intrachain). A model for the kinetics of the photoinduced volume changes of flatly and obliquely deposited chalcogenide thin films is presented. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of Nd‐doped Si thin films by laser ablation
Authors: Kawai Shinji , Komuro Shuji , Katsumata Toru
Published: January 2010

Neodymium‐doped Si thin films (Si:Nd) have been controllably synthesized over the Nd concentration ranging from 1019 to 1021 cm–3 by laser ablation, which is a useful and simple technique to control the Nd doping level into a host material. Intense and sharp Nd3+–related photoluminescence (PL) is observed from 10 K up to room temperature. From the PL spectra and their temperature and Nd concentration dependence, it is found that Nd3+ emissions result from the indirect excitation of Nd3+ through the energy transfer of electron‐hole pairs created in the SiOx host, which is formed into the Si matrix (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Properties of gas sensors based on photochemically deposited nano‐ crystalline SnO2 films
Authors: Ichimura Masaya , Baoleer Aodeng , Sueyoshi Tetsuya
Published: January 2010

We fabricated highly sensitive room temperature hydrogen sensors based on SnO2 films. The films were deposited by the photochemical deposition. A solution containing SnSO4 with its pH adjusted to about 1.4 by HNO3 were dropped onto the glass substrate and irradiated with the UV light. After 5min irradiation, the substrate was washed with water and dried before dropping the new solution. The films were fabricated by repeating this process. The sample annealed at 200 °C showed current increase by a factor >104 within 1 min for 5000 ppm hydrogen at room temperature. The removal of hydrogen from the ambient caused only a small decrease in the current, but the current decreased by more than three order of magnitude almost instantly upon subsequent exposure to air. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fine particles in amorphous silicon germanium thin films
Authors: Bhaduri Ayana , Chaudhuri Partha
Published: January 2010

We have regulated the number density and the size of the fine particles/clusters called nanoparticles into the a‐SiGe:H films deposited from silane and germane diluted in hydrogen by applying a square wave pulse modulations (SWPM) of the rf (13.56 MHz) amplitude in plasma enhanced chemical vapor deposition (PECVD). The plasma “on” time Ton and “off” time Toff were controlled over a wide range from 300 μsec to 30 msec. Growth rate (γr) of the number density (Nr) of the particles of size r shows a lognormal dependence on r. Tendency towards formation of nanocrystallites was observed on reducing the Ton. Ge content within nanocrystallites was found to increase with decrease in nanocrystallites size. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Attenuation of electromagnetic radia‐ tion by graphite‐epoxy composites
Authors: Vovchenko Ludmila , Matzui Ludmila , Oliynyk Viktor , Launetz Vilen
Published: January 2010

This work presents the results of investigations of the electromagnetic shielding efficiency of composite materials (CMs) based on epoxy resin and thermoexfoliated graphite (TEG). The measurements were performed in the wide region of electromagnetic radiation (EMR) frequency from 25.5 to 77.5 GHz. It was shown that structure and morphology of the graphite fillers influence the efficiency of electromagnetic shielding. For example, the composites with nanodispersed TEG (0.56–5.9 vol%) are characterized by low value of transmission coefficient αtr in comparison with composites with TEG or TEG2 (TEG subjected to repeated oxidation and thermoexfoliation): αtr is equal to (–29) dB for CM 10wt%TEG2+epoxy (at the specimen's thickness h =0.6 mm). The real part of permittivity ϵ ′ has been determined for the epoxy CMs with nanoTEG as filler. It also was found that electromagnetic shielding efficiency slightly increases at increasing of EMR frequency. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of carbon nanotubes using screen‐printing catalyst and its application for a field emission device
Authors: Chiang Wang‐Ta , Su Shui‐Hsiang , Wu Cheng‐Yu , Yokoyama Meiso
Published: January 2010

Iron nitrate (Fe(NO3)3.9H2O) catalyst is screen‐printed over silicon substrates and efficiently utilized to catalyze the synthesis of carbon nanotubes (CNTs) by thermal chemical vapor deposition (CVD). The concentration of iron nitrate influences the particle size distribution of the Fe catalyst, which determines the morphology of the obtained CNT arrays. H2 is introduced in varying concentrations in a CH4/N2 mixed gas during the synthesis of the CNTs, from which CNTs with uniform diameter distribution are grown. A field emission device that employs CNTs as emitters exhibits a current density of 9 mA/cm2 at an electrical field of 1.2 V/μm. This work demonstrates the potential to synthesize CNTs using a screen‐printed catalyst, which is a requirement for field emitter application at a large size. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In search of well‐started beginning science teachers: Insights from two first‐year elementary teachers
Authors: Avraamidou Lucy , Zembal‐Saul Carla
Published: January 2010

The purpose of this qualitative case study was to explore what aspects of two first‐year elementary teachers' practices were most consistent with an inquiry‐based approach, what PCK served as a mechanism for facilitating these practices, and what experiences have mediated the nature and development of these teachers' PCK. For each of the participants data included audio‐recorded interviews, video‐recorded classroom observations, lesson plans, and samples of student work. Data analysis illustrated that both participants engaged their students in question‐driven investigations, the use of observational data, making connections between evidence and claims, and communicating those claims to others. Moreover, there was clear evidence in the findings of the study that a considerable degree of coherence existed between the two participants' knowledge on one hand and their instructional practices on the other hand. The participants perceived specific learning experiences during their programs as being critical to their development. The contribution of this study lies in the fact that it provides examples of well‐started beginning elementary teachers implementing inquiry‐based science in 2nd and 5th grade classrooms. Implications of the study include the need for the design of university‐based courses and interventions by which teacher preparation and professional development programs support teachers in developing PCK for scientific inquiry and enacting instructional practices that are congruent with reform initiatives. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47:661–686, 2010
Mobility management algorithms and applications for mobile sensor networks
Authors: Wang You‐Chiun , Wu Fang‐Jing , Tseng Yu‐Chee
Published: January 2010

Wireless sensor networks (WSNs) offer a convenient way to monitor physical environments. In the past, WSNs are all considered static to continuously collect information from the environment. Today, by introducing intentional mobility to WSNs, we can further improve the network capability on many aspects, such as automatic node deployment, flexible topology adjustment, and rapid event reaction. In this paper, we survey recent progress in mobile WSNs and compare works in this field in terms of their models and mobility management methodologies. The discussion includes three aspects. Firstly, we discuss mobility management of mobile sensors for the purposes of forming a better WSN, enhancing network coverage and connectivity, and relocating some sensors. Secondly, we introduce path‐planning methods for data ferries to relay data between isolated sensors and to extend a WSN's lifetime. Finally, we review some existing platforms and discuss several interesting applications of mobile WSNs. Copyright © 2010 John Wiley & Sons, Ltd.
Next generation mobility management: an introduction
Authors: Yu F. Richard , Wong Vincent W. S. , Song Joo‐Han , Leung Victor C. M. , Chan Henry C. B.
Published: January 2010

Mobility management, which includes location management and handoff management, is essential in cellular wireless networks to provide service to mobile users. Location management enables call delivery to mobile users, while handoff management maintains the connectivity of ongoing calls while users move between cells. In next generation networks, mobile users will avail themselves with terminals capable of accessing wireless networks employing multiple technologies, thus making the task of mobility management more challenging. This paper reviews recent developments in location management, and surveys methods for handoff management between heterogeneous systems. Methods for inter‐system handoffs in packet‐switched inter‐networks are discussed according to the protocol layer in which the handoffs take place, i.e., network layer, transport layer, and application layer. Open problems for mobility management in future wireless networks are also presented. Copyright © 2010 John Wiley & Sons, Ltd.
Image‐based models of cardiac structure in health and disease
Authors: Vadakkumpadan Fijoy , Arevalo Hermenegild , Prassl Anton J. , Chen Junjie , Kickinger Ferdinand , Kohl Peter , Plank Gernot , Trayanova Natalia
Published: January 2010

Computational approaches to investigating the electromechanics of healthy and diseased hearts are becoming essential for the comprehensive understanding of cardiac function. In this article, we first present a brief review of existing image‐based computational models of cardiac structure. We then provide a detailed explanation of a processing pipeline which we have recently developed for constructing realistic computational models of the heart from high resolution structural and diffusion tensor (DT) magnetic resonance (MR) images acquired ex vivo. The presentation of the pipeline incorporates a review of the methodologies that can be used to reconstruct models of cardiac structure. In this pipeline, the structural image is segmented to reconstruct the ventricles, normal myocardium, and infarct. A finite element mesh is generated from the segmented structural image, and fiber orientations are assigned to the elements based on DTMR data. The methods were applied to construct seven different models of healthy and diseased hearts. These models contain millions of elements, with spatial resolutions in the order of hundreds of microns, providing unprecedented detail in the representation of cardiac structure for simulation studies. Copyright © 2010 John Wiley & Sons, Inc.

This article is categorized under:

Analytical and Computational Methods > Computational Methods
Training Higher Surgical Trainees in Laparoscopic Common Bile Duct Exploration
Authors: Tutton Matthew G. , Pawa Nikhil , Arulampalam Tan H. A. , Motson Roger W.
Published: January 2010

Background

Laparoscopic common bile duct (CBD) exploration is regarded as a safe, definitive procedure for ductal calculi, avoiding the complications of endoscopic retrograde cholangiopancreatography. We aimed to evaluate the outcomes of laparoscopic CBD exploration carried out by trainees compared to those of an experienced consultant (R.W.M.).

Methods

A prospective database of all cases of laparoscopic CBD exploration over a 15‐year period was analyzed retrospectively. All patients underwent a four‐port technique and intraoperative cholangiography. Patient demographics, operative technique, success, and complications were analyzed.

Results

The median age of patients undergoing laparoscopic CBD exploration was 65 years (range 14–94 years). In all, 187 (79%) of the CBD explorations were performed by one consultant and 48 (21%) by trainees. Calculi were successfully cleared in 141 (88%) and 43 (96%), respectively. There were two (<1%) conversions to an open procedure in the total group. The median operating time was 130 minutes in the consultant group versus 150 minutes in the trainee group (p < 0.05, Mann‐Whitney U‐test). There was no significant difference in CBD clearance rate, surgical approach, or complication rate between consultant and trainees (Fisher’s exact test).

Conclusions

Laparoscopic CBD exploration is a safe procedure in both consultant and trainee hands. With appropriate training, surgical trainees can achieve equivalent outcomes in CBD clearance with no significant difference in complication rates.
Seven Sins of Humanitarian Medicine
Authors: Welling David R. , Ryan James M. , Burris David G. , Rich Norman M.
Published: January 2010

The need for humanitarian assistance throughout the world is almost unlimited. Surgeons who go on humanitarian missions are definitely engaged in a noble cause. However, not infrequently, despite the best of intentions, errors are made in attempting to help others. The following are seven areas of concern: 1. Leaving a mess behind. 2. Failing to match technology to local needs and abilities. 3. Failing of non‐governmental organizations (NGO’s) to cooperate and help each other, and and accept help from military organizations. 4. Failing to have a follow‐up plan. 5. Allowing politics, training, or other distracting goals to trump service, while representing the mission as “service”. 6. Going where we are not wanted, or needed and/or being poor guests. 7. Doing the right thing for the wrong reason. The goal of this report is to discuss these potential problems, with ideas presented about how we might do humanitarian missions more effectively.
Wohnstandortentscheidungen von Haushalten am Beispiel Mannheim
Authors: Gans Paul , Schmitz-Veltin Ansgar , West Christina
Published: January 2010

By the end of 2025, Mannheim’s population will have increased slightly to reach 312,700. Just as in other major cities in Germany, the fear in Mannheim is that continuing suburbanisation and net gains in population resulting from immigration will lead to long-term social segregation. It is against this background that the city of Mannheim joined forces with the GBG-Mannheimer Wohnungsbaugesellschaft mbH, a local housing association, to commission a study into the motives underlying relocation. Starting with a brief attempt to contextualise the issue at hand, this paper details the procedure applied and presents a comparative survey based on demographic structure and the motives underlying relocation for households moving into, out of, or within the city. One topic of special interest is city-to-hinterland migration and the conditions under which such households would be prepared to return to the city. The study concludes by showing how Mannheim’s residential neighbourhoods are capable of satisfying quite diverse housing needs; consequently, the city is well placed to enhance its appeal as a place to live and to counter the trend towards suburbanisation.
Multiple homoclinic solutions for singular differential equations
Authors: Luo Guangping , Lan Kunquan , Zhu Changrong
Published: January 2010

The homoclinic bifurcations of ordinary differential equation under singular perturbations are considered. We use exponential dichotomy, Fredholm alternative and scales of Banach spaces to obtain various bifurcation manifolds with finite codimension in an appropriate infinite-dimensional space. When the perturbative term is taken from these bifurcation manifolds, the perturbed system has various coexistence of homoclinic solutions which are linearly independent.