bluuebunny/crossref_metadata_2025 huggingface dataset:
Branched and Functionalized Polybutadienes by a Facile Two‐Step Synthesis
Authors: Wurm Frederik , López‐Villanueva Francisco‐J. , Frey Holger
Published: March 2008

Anionic polymerization was used to prepare silane‐endfunctionalized polybutadiene macromonomers with different molecular weights ranging from 9 000 to 34 000 g · mol−1. These were polymerized by a hydrosilylation reaction in bulk to obtain branched polymers, using Karstedt's catalyst. Surprisingly, the addition of monofunctional silanes during the polymerization showed only a minimal effect concerning the degree of polymerization. Furthermore, it was possible to introduce a variety of functional silanes without increasing the overall number of reaction steps by a convenient AB2 + A type “pseudocopolymerization” method. All branched polymers were analyzed by SEC, SEC‐MALLS, SEC‐viscosimetry. 1H NMR spectroscopy, and DSC concerning their branching ratio. The branching parameters for the branched polymers exhibited similar characteristics as for hyperbranched polymers obtained from conventional AB2 monomers. Detailed kinetic studies showed that the polymerization occurred very rapidly in comparison to the hydrosilylation polymerization of classical AB2 type carbosilane monomers.

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Formation Mechanism of Polyaniline Nanotubes by a Simplified Template‐Free Method
Authors: Ding Hangjun , Shen Jiaoyan , Wan Meixiang , Chen Zhaojia
Published: March 2008

PANI nanotubes with diameters of 100–150 nm with conductivities of single nanotubes as high as 30.6 S · cm−1 were directly oxidized with APS in the absence of hard templates and acidic dopants. The high conductivity was shown to result from protons produced during the polymerization. The pH decreases with increasing polymerization time, and the morphology changes from hollow spheres to short and long tubes. It is proposed that the micelles formed by the aniline monomer in aqueous solution serve as a soft template for forming hollow spheres at the initial stage. As the polymerization proceeds, these hollow spheres are linearly aggregated and elongated to form short and long tubes.

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Methacrylic Polymers Containing Optically Active Side‐Chain Carbazole: Synthesis, Characterization and Photoconductive Properties
Authors: Angiolini Luigi , Benelli Tiziana , Giorgini Loris , Golemme Attilio , Mauriello Francesco , Salatelli Elisabetta , Termine Roberto
Published: March 2008

Two novel optically active polymethacrylates bearing in the side chain a cyclic chiral group of one prevailing absolute configuration linked to the carbazole chromophore, deriving from the related monomers (S)‐(−)‐3‐methacryloyloxy‐N‐[3‐(9‐ethylcarbazolyl)]pyrrolidine [(S)‐(−)‐MECP] and (S)‐(+)‐2‐methacryloyloxy‐N‐[3‐(9‐ethylcarbazolyl)]succinimide [(S)‐(+)‐MECSI], have been prepared and characterized with the aim to obtain materials suitable to photoconductive applications. Poly[(S)‐(−)‐MECP] and poly[(S)‐(+)‐MECSI] exhibit remarkable thermal stability, with glass transition temperature around 200 °C and decomposition temperatures in the range 330–350 °C. Spectroscopic, thermal and chiroptical characterizations indicate the occurrence of dipolar interactions among the side chain moieties and the presence of chiral conformation at least for chain segments of the macromolecules. The photoconductive properties are discussed in terms of extent of conjugation in the side chain based on the electron‐acceptor or electron‐donator properties of the optically active ring linked to the carbazole group.

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Synthesis and Characterization of Pyrene‐Centered Starburst Oligofluorenes
Authors: Liu Feng , Lai Wen‐Yong , Tang Chao , Wu Hong‐Bin , Chen Qing‐Quan , Peng Bo , Wei Wei , Huang Wei , Cao Yong
Published: March 2008

A series of starburst materials (T1–T3) based on a pyrene core with four oligofluorene arms of different length have been synthesized and characterized. The starburst materials show good film forming ability and sky blue fluorescence. Electroluminescent devices take on a stable blue emission and the device performance increases with an increase in arm length. The single‐layered device made of T3 has a maximum brightness of over 2 700 cd · m−2 and a maximum current efficiency of 1.75 cd · A−1, which is among the best in starburst material devices. The morphology of T1–T3 has been studied by atomic force microscopy. The starburst oligofluorenes with different arm lengths show a distinctive texture, which indicates the size dependent morphology of the starburst materials.

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Kinetics of the Anionic Polymerization of 1,3‐Butadiene Using an Initiator Composed of Alkyl Aluminium, n‐Butyllithium and Barium Alkoxide to Produce High trans‐1,4‐Polybutadiene
Authors: Tapia Juan J. Benvenuta , López José A. Tenorio , Nájera Rafael Herrera
Published: March 2008

A kinetic model that considers three geometric active sites—cis, trans and vinyl—was proposed to the study polymerization reaction of high 1,4‐trans‐polybutadiene (TPBD) prepared by means of anionic living polymerization using an initiator composed of alkyl aluminium, n‐butyllithium and barium alkoxide. The conversion and dyad sequence distribution was correctly predicted; the kinetic results indicated that the microstructure and sequence distribution do not change with the conversion and temperature within the range of temperature investigated (40–80 °C). In addition, it was observed that the addition mechanism of butadiene to the active sites is entropic.

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Treatment of uncomplicated vaso‐occlusive crises in children with sickle cell disease in a day hospital
Authors: Raphael Jean L. , Kamdar Aditi , Beavers M. Brooke , Mahoney Donald H. , Mueller Brigitta U.
Published: March 2008

Background

Day hospital management for patients with sickle cell disease experiencing uncomplicated vaso‐occlusive pain crises has been described in adult populations as an alternative care delivery system. The objective of this study was to characterize and descriptively assess the benefits of a day hospital exclusively designed for children.

Procedure

We retrospectively studied all admissions to the Day Hospital at the Texas Children's Sickle Cell Center since its inception in 2000. A Day Hospital admission was defined as a minimum of two consecutive days of aggressive pain management as an outpatient, including intravenous hydration and analgesics, supported by home treatment over night with oral analgesic and anti‐inflammatory agents. We gathered data on demographics, incoming pain score, provider type, opioid administration, length of stay, and needs for higher level care.

Results

A total of 35 patients, ages 2–19, accounted for 80 episodes during the study period. The median incoming pain score was 8 on a scale from 1 to 10. The median length of stay was 2 days. The return rate for acute care within 48 hr for persistent symptoms was 7%. Seventy‐one percent of patients admitted to the Day Hospital were treated without requiring transfer to inpatient care for escalating pain or medical needs.

Conclusions

We conclude that a dedicated Day Hospital facility has the potential to provide patient‐centered, effective, and timely management of vaso‐occlusive crises in children as well as adults. Pediatr Blood Cancer 2008;51:82–85. © 2008 Wiley‐Liss, Inc.
Pathologic, radiographic and molecular findings in three fetuses diagnosed with HEM/Greenberg skeletal dysplasia
Authors: Konstantinidou Anastasia , Karadimas Charalampos , Waterham Hans R. , Superti‐Furga Andrea , Kaminopetros Petros , Grigoriadou Maria , Kokotas Haris , Agrogiannis George , Giannoulia‐Karantana Aglaia , Patsouris Efstratios , Petersen Michael B.
Published: March 2008

Background

Greenberg skeletal dysplasia is a very rare, autosomal recessive, in utero, lethal chondrodystrophy for which only eight index cases of diverse ethnic origin have been reported so far. The defect is associated with a defect in cholesterol biosynthesis and due to mutations in the gene encoding the lamin B receptor (LBR).

Methods

A familial case of three fetuses of a consanguineous Greek couple is presented including prenatal, physical, radiographic, histopathologic, and molecular genetic findings.

Results

The tentative diagnosis of Greenberg skeletal dysplasia based on pathological findings was confirmed by the identification of a homozygous, N547D amino acid substitution in the LBR gene in the third affected fetus.

Conclusion

The present case represents the ninth described case of Greenberg dysplasia and the second case of Greek origin. The characteristic ‘moth‐eaten’ radiographic appearance is already seen at 13 weeks' gestational age. Copyright © 2008 John Wiley & Sons, Ltd.
Preliminary results of fetal Rhc examination in plasma of pregnant women with anti‐c
Authors: Orzińska A. , Guz K. , Brojer E. , Żupańska B.
Published: March 2008

Objectives

Anti‐Rhc antibodies may be the reason for the hemolytic disease of the newborn, therefore, noninvasive Rhc determination is important for pregnancy monitoring. For this purpose, we decided to introduce real‐time polymerase chain reaction (PCR) method.

Methods

Blood from 200 donors, plasma and whole‐blood from 11 Rhc‐negative mothers, as well as blood from fathers and newborns were examined. Rhc sensitivity and specificity were first determined by real‐time PCR using genomic DNA from donors. The same Rhc genotyping method was used for fetal Rhc detection in maternal plasma. To confirm the fetal Rhc‐negative result, plasma was tested with a panel of biallelic insertion/deletion polymorphisms for the presence of fetal DNA.

Results

The c allele assay showed full specificity. The mean Ct value for one copy of c allele diluted in C‐negative DNA was determined from extrapolating the correlation curve as 39.9. Full concordance was observed between the fetal Rhc genotypes from maternal plasma and the newborn phenotypes.

Conclusions

Preliminary results show that it is possible to examine fetal c allele of RHCE gene in the plasma of pregnant women with anti‐c by means of a noninvasive method. The diagnostic accuracy of the procedure, however, has yet to be confirmed in a larger group. Copyright © 2008 John Wiley & Sons, Ltd.
First‐trimester ADAM12s as early markers of trisomy 21: a promise still unfulfilled?
Authors: Spencer Kevin , Cowans Nicholas J. , Uldbjerg Niels , Tørring Niels
Published: March 2008

Background

Here we study the levels of ADAM12s prior to and after 10 weeks of gestation to establish further the effectiveness or otherwise of ADAM12s as an early screening marker.

Materials and Methods

Samples collected as part of routine first‐trimester screening were retrieved from storage at − 80 °C. In total, 55 samples from pregnancies with trisomy 21 were identified, 31 collected between the 6th and 9th weeks of gestation and 24 collected after the 10th week. A series of 567 gestational age‐matched samples collected during the same period formed the control group.

Results

The median, multiples of the median (MoM) ADAM12s, at a median gestation of 10.0 weeks was 0.66, which was significantly lower than in the controls (p = < 0.001) when compared by Mann–Whitney test. The median MoM in those cases (n = 31) collected prior to 10 weeks was 0.618 MoM at a median gestation of 9.1 weeks. In those collected prior to 9 weeks (n = 14) the median was 0.596 at a median gestation of 8.6 weeks.

Conclusions

The data from this study does not support data from a previous study showing ultra‐low levels of ADAM12s in pregnancies affected by trisomy 21 prior to 10 weeks of gestation. Copyright © 2008 John Wiley & Sons, Ltd.
Degradation mechanism of poly(ether‐urethane) Estane® induced by high‐energy radiation. II. Oxidation effects
Authors: Dannoux A. , Esnouf S. , Amekraz B. , Dauvois V. , Moulin C.
Published: March 2008

To predict long‐term polymer behavior during a nuclear waste storage time, radiation effects on a segmented aromatic poly(ether‐urethane) induced by high‐energy radiation under oxygen atmosphere were investigated. To obtain a predictive model of polymer radio‐oxidation during several centuries, the first step consists to elaborate the elementary degradation mechanisms. Thus, electron paramagnetic resonance (EPR), Fourier transform infra‐red spectroscopy (FT‐IR), electrospray ionisation‐mass spectrometry (ESI‐MS), and gas mass spectrometry were carried out to identify radicals, chemical modifications, and gases to reach the radio‐oxidative mechanism at doses inferior than 1000 kGy. Degradation mainly occurs at urethane bonds and in polyether soft segments that produces stable oxidative products as formates, alcohols, carboxylic acids and H2, CO2 and CO gases. Predominant degradation occurred at polyether soft segments and crosslinking is in competition with scission. On the basis of the results, a mechanism of degradation for aromatic poly(ether‐urethane) is proposed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 861–878, 2008
Influence of β2‐adrenoceptor polymorphisms on the response to chronic use of albuterol in asthmatic children
Authors: Giubergia Verónica , Gravina Luis Pablo , Castaños Claudio , Chertkoff Lilien , Grenoville Mario
Published: March 2008

Background

Several studies have suggested that after regular use of short acting β2‐agonists the bronchodilator effect of the drug may decline and this condition would be related to polymorphisms of the β2‐adrenergic receptor (β2‐AR).

Objective

To assess the frequency of β2‐AR polymorphisms in asthmatic children from Argentina, and to evaluate their influence on bronchodilator desensitization to albuterol over a 4‐week treatment.

Methods

β2‐AR genotypes were determined in 117 children with asthma and 101 of them were under 4 weeks treatment with albuterol. Spirometric changes in FEV1 were recorded at the beginning (day 1) and at the end of the study (day 30) and compared to genotypes at position 16 and 27 of the receptor. The frequency of the polymorphisms was calculated in all population.

Results

The presence of glutamine at position 27 (Gln27) was significantly more frequent in this Argentinean study population than in other Caucasian populations. The homozygosity for Gln27 polymorphism was associated to a desensitization of the receptor with a decline in the bronchodilator response to albuterol after chronic use.

Conclusion

Gln27 polymorphism might be a marker for adverse clinical outcomes with chronic β2‐agonist exposure in children with asthma from Argentina. Pediatr Pulmonol. 2008; 43:421–425. © 2008 Wiley‐Liss, Inc.
Establishment of a web‐based registry for rare (orphan) pediatric lung diseases in the United Kingdom: The BPOLD registry
Authors: Laverty A. , Jaffé A. , Cunningham S.
Published: March 2008

Background

Children with orphan lung diseases (defined as a prevalence of <1 in 2000) receive suboptimal care due to a lack of understanding of pathophysiology and management.

Aim:

To develop a low cost, multidisease, web‐based registry for children with rare lung diseases.

Methods

The British Pediatric Orphan Lung Disease (BPOLD) electronic registry was established to provide a web‐based method for recording monthly incidence data on nine rare pediatric respiratory diseases (www.bpold.co.uk). An email reporting system was developed which required clinicians to input a username and password to respond following a monthly email reminder. The initial reporting rate was poor despite many registrants. The method for reporting was subsequently streamlined enabling reporting to be done via email by a single mouse‐click. A follow‐up email, with consent forms as attachments, was automatically sent to positive respondents, with negative responses recorded directly to the database. Non‐responders receive a reminder email after 2 weeks.

Results

Initially 101 respiratory clinicians registered via the BPOLD site, responding 162 times over 17 months. In the 12 months following redevelopment (total 12 monthly group emails) 143 of 222 BPRS members (64%) have provided 1,001 responses. Forty‐eight clinicians (34% of responders) have responded to 10–12 group emails, with the next highest total being those responding to one only. One hundred fifty‐eight cases of orphan lung disease have been identified.

Conclusions

We have demonstrated the successful establishment of a low cost, web‐based registry for children with rare lung diseases. There is an urgent need for European and International collaboration with the establishment of electronic registries for children with rare diseases, if the inequities of health care are to be addressed. A web‐based approach, similar to the one we have developed, will enable this. Pediatr Pulmonol. 2008; 43:451–456. © 2008 Wiley‐Liss, Inc.
Diagnosing asthma in children: What is the role for methacholine bronchoprovocation testing?
Authors: Liem Joel J. , Kozyrskyj Anita L. , Cockroft Donald W. , Becker Allan B.
Published: March 2008

Objective

To determine whether measurement of airways responsiveness to methacholine can help physicians diagnose asthma in children.

Methods

Children from the 1995 Manitoba birth cohort were assessed by asthma specialists, had skin testing and measurement of airways responsiveness to methacholine (PC20). We selected children with doctor‐diagnosed asthma and healthy children as controls (no asthma, no allergic rhinitis, negative skin tests). Sensitivities and specificities for asthma were calculated. Receiver operating curves were calculated to determine the best fit of the methacholine challenge as a diagnostic test.

Results

640 children were assessed. Two hundred fifteen children with doctor diagnosed asthma and 197 healthy controls successfully completed a methacholine challenge. Airways hyperresponsiveness was a moderately sensitive and specific measure for the diagnosis of asthma in girls, whether atopic (sensitivity of 71% and specificity of 69% at PC20 ≤ 4.0 mg/ml) or not (sensitivity of 77% and specificity of 53% at PC20 ≤8.0 mg/ml). Airways hyperresponsiveness was also helpful for the diagnosis of asthma in atopic boys (sensitivity of 67% and specificity of 75% at PC20 ≤2.0 mg/ml), but of absolutely no help in the diagnosis of asthma in nonatopic boys.

Conclusion

Measurement of airways hyperresponsiveness to methacholine can be useful in children who are atopic and of some value in nonatopic girls. The presence or absence of airways hyperresponsiveness to methacholine is of no help for the diagnosis of asthma in nonatopic boys. Laboratory tests must be placed in context of the clinical assessment of children for asthma. Pediatr Pulmonol. 2008; 43:481–489. © 2008 Wiley‐Liss, Inc.
Workplace safety climate assessment based on behaviors and measurable indicators
Authors: Yu Ming , Sun Linyan , Egri Carolyn
Published: March 2008

Previous conceptualizations of safety climate present snapshots of the state of workplace safety. In reality, the factors of workplace safety climate are complex and need to be analyzed using a systemic approach. In this article, we expand on the customary concept of safety climate, and propose a systemic research framework that integrates four study fields: engineering, ergonomics, operation management, and technology management. In this framework, we define micro and macro safety climate concepts based on the study object and organizational hierarchy.

Our model focuses on two safety climate dimensions: behaviors and measurable indicators. First, we propose that the safety process consists of four basic behaviors: perceive, decide, communicate, and act (PDCA). These PDCA behaviors constitute a safety climate sociotechnical system involving the three roles of operator, supervisor, and manager. We then present 12 measurable indicators of PDCA behaviors for each safety climate research field to advance the systematic assessment of both qualitative and quantitative facets of safety climate. © 2008 American Institute of Chemical Engineers Process Saf Prog, 2008
Microstructure and electrical properties of (1–x)(K0.5Na0.5)NbO3–x BiFeO3 piezoelectric ceramics
Authors: Li Xiang , Wu Lang , Xiao Dingquan , Zhu Jianguo , Yu Ping , Jiang Yihang , Wu Jiagang
Published: March 2008

Lead–free ceramics (1–x)(K0.5Na0.5)NbO3–x BiFeO3 doped with 1 mol% Fe2O3 (KNNBF/x) have been synthesized by pressureless sintering. With the Fe2O3 doping, the KNNBF/x ceramics can be well sintered at 1085–1100 °C and exhibit a pure perovskite structure with x < 0.013. It was found that the crystal structure of the KNNBF/x ceramics changed from orthorhombic to tetragonal and then to pseudocubic phase with the increase of BiFeO3 content. The composition KNNBF/0.013 near the tetragonal symmetry that separates the orthorhombic and pseudocubic phases exhibits improved electrical properties: d33 = 173 pC/N, kp = 0.40, εr = 905, tan δ = 4%, Pr = 26 μC/cm2, and Ec = 11.2 kV/cm, with a high Curie temperature (TC) of about 388 °C. Our results suggest that KNNBF/x are promising lead‐free high temperature piezoelectric ceramics. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination of in‐plane thermal conductivity of Nax Co2O4 single crystals via a parallel thermal conductance (PTC) technique
Authors: Tang Xiaofeng , Aaron Kelvin , He Jian , Tritt Terry M.
Published: March 2008

A novel parallel thermal conductance (“PTC”) system was specifically developed to conduct the steady state thermal conductivity measurement on small size samples such as single crystals of Nax Co2O4 as reported here. The accuracy and reproducibility of the PTC system has been confirmed by measuring several standard reference materials. The in‐plane thermal conductivity κ of Nax Co2O4 single crystals grown by a NaCl flux method was measured from 10 K to 300 K and κ was found to be ∼5 W m–1 K–1 at 300 K. The phonon mean free path (MFP) is estimated to be lph ∼ 9 Å at 300 K, which is comparable to the lattice constant but much smaller than the reported MFP of conducting carriers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum‐size effect and intersubband transitions in zinc blend AlxGa1–xN quantum cubes embedded in AlN matrix
Authors: Feng Shih‐Wei , Chen Kuei‐Hsien , Lai Chih‐Ming
Published: March 2008

In this work, we study the quantum‐size effect and intersubband (ISB) transitions in Zinc Blende (ZB) quantum structures by using a series expansion model to calculate the band structures of AlxGa1–xN quantum cubes. Without the quantum confined Stark (QCSE) effect, the quantum size effect and size‐tunable emission properties of ZB AlxGa1–xN quantum cubes can be really explored. Simulations results show the important factors of the composition, cluster size, quantum confined potential, effective mass, and strain in determining the optical properties of ZB AlxGa1–xN quantum cubes. For those quantum cubes with larger sizes and composition contrasts, ISB transitions in the conduction band are suitable to develop devices operating in the telecommunication windows. In addition, AlxGa1–xN quantum cubes can take their advantages of size‐tunable emission properties, ISB transitions, and ISB absorptions in devices such as LEDs, Lasers, telecommunication devices, and photo detectors. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correlation between the violet luminescence intensity and defect density in AlN epilayers grown by ammonia‐source molecular beam epitaxy
Authors: Hoshi Takuya , Koyama Takahiro , Sugawara Mariko , Uedono Akira , Kaeding John F. , Sharma Rajat , Nakamura Shuji , Chichibu Shigefusa F.
Published: March 2008

Intensity ratios of deep cathodoluminescence (CL) bands at 4.6, 3.8 and 3.1 eV to the near‐band‐edge emission of AlN epilayers grown by NH3‐source molecular beam epitaxy were correlated with the change in S parameter of positron annihilation measurement, which represents the concentration or size of Al vacancies (VAl). The origins of the deep emission bands were assigned to donor‐acceptor pairs associated with VAl and/or VAl‐defect complexes. The VAl concentration was decreased by adjusting the flux ratio of NH3 to Al and growth temperature, resulting in observation of fine excitonic features in the CL spectra. From the energy separation between the ground and first excited states, the binding energy of free A ‐exciton was estimated to be 48 meV. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Robotic‐assisted gynaecological surgery—establishing training criteria; minimizing operative time and blood loss
Authors: Pitter Michael C. , Anderson Patrick , Blissett Amelia , Pemberton Nicola
Published: March 2008

Background

The objective was an evaluation of operative time and estimated blood loss (EBL) as a function of experience in gynaecological robotic surgery.

Method

A retrospective analysis of 40 consecutive cases (approximately one case/week) over a 1 year period using the da Vinci® robotic system was performed, using data from two institutions, Newark Beth Israel Medical Center and Hackensack University Medical Center. Information was obtained from a single surgeon. Among the 40 cases there were 17 hysterectomies and 23 myomectomies. Each patient met the criteria of benign disease. In each institution, a da Vinci® system using three instrument arms and a camera arm was employed for every operation.

Results

Tests of differences in means were performed to compare the two groups. In group I (cases 1–20) the mean uterine volume was 863.0 cc and was similar to Group II (cases 21–40) at 632.6 cc. There was no significant difference between the groups when comparing blood loss; means were 86 cc for group I and 62.5 cc for group II. Operative time between groups, however, showed a significant difference (mean of 211.8 min for group 1 compared to 151 min for group 2; p < 0.05) and console time demonstrated a similar trend (mean for group 1 was 159.8 min compared to 90.8 min for group 2; p < 0.05). There were no conversions to laparotomy. Body mass index (BMI) and prior abdominal surgery were not significantly different. Multivariate regressions on operative time and EBL were performed, controlling for uterine weight and volume. The effect of experience on operative time was significant and negative; the coefficient on EBL was not significant.

Conclusion

This study demonstrates statistical improvement in operative time after the first 20 cases for a single surgeon. This information could be used to establish criteria for training surgeons. Copyright © 2008 John Wiley & Sons, Ltd.
Heteroepitaxial growth of cubic SiC on Si using very‐high‐frequency plasma at atmospheric pressure
Authors: Kakiuchi Hiroaki , Ohmi Hiromasa , Aketa Masatoshi , Nakamura Ryota , Yasutake Kiyoshi
Published: March 2008

The heteroepitaxial growth of cubic silicon carbide (3C‐SiC) on Si(001) at a substrate temperature of 800 °C was investigated using atmospheric‐pressure plasma excited by very‐high‐frequency (VHF) power. The carbonization process of the Si surface was first studied using plasma of He, H2 and CH4 mixtures to suppress the undesired influences of the large lattice mismatch between Si and 3C‐SiC. A (001)‐oriented 3C‐SiC layer, with thickness of approximately 3 nm and a root mean square roughness of 0.23 nm, was formed by supplying the optimum VHF power for a H2 concentration of 10% (H2/CH4 ratio of 40). Following the carbonization process, 3C‐SiC films were deposited from a CH3SiH3 single source or CH4 and SiH4 dual sources by varying the atomic concentration ratio (C/Si). The crystal quality of the deposited films was characterized using infrared absorption spectroscopy, transmission electron microscopy and selected‐area electron diffraction. The results showed that increasing the C/Si ratio was essential to improve both the deposition rate and the crystal quality. The 3C‐SiC film deposited at C/Si = 10 exhibited the (001) 3C‐SiC growth epitaxially aligned to the Si matrix, although it included a high density of planar defects originating from twinned 3C‐SiC. Copyright © 2008 John Wiley & Sons, Ltd.
Estimation of propensity scores using generalized additive models
Authors: Woo Mi‐Ja , Reiter Jerome P. , Karr Alan F.
Published: March 2008

Propensity score matching is often used in observational studies to create treatment and control groups with similar distributions of observed covariates. Typically, propensity scores are estimated using logistic regressions that assume linearity between the logistic link and the predictors. We evaluate the use of generalized additive models (GAMs) for estimating propensity scores. We compare logistic regressions and GAMs in terms of balancing covariates using simulation studies with artificial and genuine data. We find that, when the distributions of covariates in the treatment and control groups overlap sufficiently, using GAMs can improve overall covariate balance, especially for higher‐order moments of distributions. When the distributions in the two groups overlap insufficiently, GAM more clearly reveals this fact than logistic regression does. We also demonstrate via simulation that matching with GAMs can result in larger reductions in bias when estimating treatment effects than matching with logistic regression. Copyright © 2008 John Wiley & Sons, Ltd.
Preliminary data on the yellow ochers at the mine of Via Tirapelle in Verona (Italy)
Authors: Cavallo G. , Zorzin R.
Published: March 2008

The mine of Via Tirapelle in Verona is a paleokarst cave filled with insoluble material coming from the dissolution of the carbonatic formation; the size distribution generally belongs to the class of lime and clay.

No more information is available on these natural earths.

The analysis carried out in the past on these materials refer that the pigment was limonite.

X‐ray diffraction powder (XRD) analysis allows to refer that the yellow ocher is only the orthorhombic goethite. Goethite is locally associated with calcite, quartz and dolomite. Ankerite was found as a constituent of two samples deriving from the replacement of Fe inside the dolomite. X‐ray fluorescence (XRF) analysis of major elements shows that the contents of Fe are related to goethite and ankerite, and to the poorly crystalline phases.

Inductively coupled plasma emission spectrometry (ICP‐ES) analysis of trace elements Cd, Co, Cr, Cu, Ni, Pb, Zn shows a linear correlation between Fe2O3 and Cd, Cu, Ni, Zn. Copyright © 2008 John Wiley & Sons, Ltd.
XANES study on novel mixed valent A2U4O12(A = K, Rb or Tl) uranates
Authors: Misra Nand Lal , Lahiri Debdutta , Singh Mudher Khush Dev , Olivi Luca , Sharma Surinder M.
Published: March 2008

Alkali metal (Na, K, Rb, and Cs) uranates are likely to form in operating or transient reactor conditions by interaction of coolant/fission products with uranium oxide fuel. The valency of uranium in uranates formed in reactor operating conditions plays an important role in migration of fission products as well as in uranium diffusion in the fuel and thus determines fuel behavior during reactor operation. X‐ray absorption near edge structure (XANES) measurements on uranates K2U4O12, Rb2U4O12, and Tl2U4O12 have been made to determine the valency of uranium in these compounds. XANES analysis reveals that uranium is present in mixed valence state in these compounds, as U(V) and U(VI). The ratio of uranium (V) to (VI) states (determined from XANES analysis), in all the compounds, does not conform to 1:1 as required by their chemical formula. The reason for this mismatch may be the instability of U(V) state during sample preparation in these compounds as well as reference compounds. Copyright © 2008 John Wiley & Sons, Ltd.
The complementary use of PIXE‐α and XRD non‐destructive portable systems for the quantitative analysis of painted surfaces
Authors: Pappalardo L. , Pappalardo G. , Amorini F. , Branciforti M. G. , Romano F. P. , de Sanoit J. , Rizzo F. , Scafiri E. , Taormina A. , Gatto Rotondo G.
Published: March 2008

This work presents the results of a non‐destructive analysis carried out using the portable PIXE‐α (particle‐induced x‐ray emission) system developed in collaboration by the INFN/LANDIS (Catania, Italy), the CNR/IBAM (Catania, Italy) and the CEA/LIST (Saclay, France), and the portable XRD (x‐ray diffraction) diffractometer recently upgraded at the INFN/LANDIS.

It is shown that using a combination of the two techniques, quantitative analysis is possible in some cases. The results of its application to Roman fresco fragments obtained from different archaeological sites in Catania (Italy) are presented. These results make it possible to identify the quantitative presence of various pigments: coloured earths, ochre, hematite, goethite, cinnabar, and Egyptian blue have been identified and quantified. Copyright © 2008 John Wiley & Sons, Ltd.
X‐ray fluorescence analysis of lead in tin coating using the theoretical intensity of scattered x‐rays
Authors: Ochi H. , Watanabe S. , Nakamura H.
Published: March 2008

Quantitative analysis of lead in tin‐plated electronic components is reported. The fundamental parameter method is used, by using bulk solders as the standard sample. The scattered x‐ray monitor method is additionally used to obtain the measured intensity ratio of fluorescent and scattered x‐rays to correct the results. This is necessary because the electronic components analyzed do not have a large and smooth surface suitable for quantitative analysis. An analytical result of 6.0 µm film thickness and 1430 ppm lead concentration is obtained for a 5.4 µm thickness and 1388 ppm concentration sample using the scattered x‐ray monitor method. Copyright © 2008 John Wiley & Sons, Ltd.
The Potential for Essential Trauma Care to Empower Communities and Tackle Inequities
Authors: Nakahara Shinji , Ichikawa Masao , Kimura Akio , Yoshida Katsumi
Published: March 2008

In an attempt to address rapidly increasing injuries in low‐income and middle‐income countries (LMICs), the Essential Trauma Care Project was started with the goal of standardizing trauma care systems. This project, although part of “vertical” essential health services, has the potential to strengthen the health care system as a whole and to empower communities. Improved diagnosis, triage, referral, communication, and transport benefit the integrated health care systems weakened by vertical approaches. This project mobilizes existing resources, including lay people, to establish a “local model of prehospital care,” which can raise community capability and foster trust in health systems. This article describes how this project can be an intersection between vertical and horizontal approaches.
Chimeras of bacterial translation factors Tet(O) and EF‐G
Authors: Thakor Nehal S. , Nechifor Roxana , Scott Paul G. , Keelan Monika , Taylor Diane E. , Wilson Kevin S.
Published: March 2008

Ribosomal protection proteins (RPPs) confer bacterial resistance to tetracycline by releasing this antibiotic from ribosomes stalled in protein synthesis. RPPs share structural similarity to elongation factor G (EF‐G), which promotes ribosomal translocation during normal protein synthesis. We constructed and functionally characterized chimeric proteins of Campylobacter jejuni Tet(O), the best characterized RPP, and Escherichia coli EF‐G. A distinctly conserved loop sequence at the tip of domain 4 is required for both factor‐specific functions. Domains 3–5: (i) are necessary, but not sufficient, for functional specificity; and (ii) modulate GTP hydrolysis by EF‐G, while minimally affecting Tet(O), under substrate turnover conditions.
Unconventional secretion of fibroblast growth factor 2 and galectin‐1 does not require shedding of plasma membrane‐derived vesicles
Authors: Seelenmeyer Claudia , Stegmayer Carolin , Nickel Walter
Published: March 2008

Various molecular mechanisms of unconventional secretion of fibroblast growth factor 2 and galectin‐1 have been proposed. A non‐vesicular pathway that is based on direct translocation across the plasma membrane has been described. In other studies, however, release into the extracellular space of cell‐derived vesicles was implicated in both FGF‐2 and Gal‐1 secretion. Such vesicles were proposed to originate either from plasma membrane shedding or by the release of exosomes. Employing an inhibitor of plasma membrane blebbing and based on a quantitative biochemical analysis of cell culture supernatants for vesicles potentially carrying FGF‐2 or Gal‐1, we demonstrate that both FGF‐2 and Gal‐1 are not exported by shedding of plasma membrane‐derived vesicles.
Hospital Policy Decisions: Process and Action
Authors: Tighe Isabella
Published: March 2008

HOSPITAL POLICY DECISIONS: PROCESS AND ACTION By Arthur B. Moss, Wayne G. Broehl, Jr., Robert H. Guest and John W. Hennessey, Jr., 332 pages, G. P. Putnam's Sons, New York, 1966. Price $8.50.
Staff Competence in Dealing with Traditional Approaches
Authors: Kastrup M.
Published: March 2008

Health care and health care systems should be seen and understood in their socio-cultural context. Modern urbanized societies are likely to exhibit health care pluralism, and different therapeutic approaches are available side-by-side. The various models may take their origin in different cultural traditions, but in most societies one type of care is at a given time considered “above” the others. However health care activities in all societies show a degree of interrelation, reflecting societal changes in which normative practices, value systems and structures change over time. In the current Western health systems evidence-based biomedical care is the prevailing system taught to all professionals.

The present paper outlines the prevailing health paradigms, and the advantages and shortcomings of the various approaches and their relation to modern care will be discussed. With increased multicultural backgrounds of patients there is a need for mental health professionals to recognize the existence of traditional approaches and be aware of the parallel systems of care. Competent treatment of such patients requires that mental health professionals are aware of this and exhibit a willingness and ability to bridge between the more traditional and the Western approaches to treatment. The delineations and various aspects of the concept cultural competence and its dimensions will be discussed from a clinical perspective.

Comparative studies of the various Western and the traditional approaches respectively will be reviewed.
On the effect of distributed cooling in natural ventilation
Authors: LIVERMORE S. R. , WOODS A. W.
Published: March 2008

We examine the natural ventilation flows which develop when a low-level heat source interacts with a distributed zone of cooling at high level in an enclosed space. We develop some new analogue laboratory experiments in which we use a saline plume to model a localized heat source and a heated plate to model a distributed source of cooling. The experiments show that in a building with a low-level point source of heating, a two-layer steady stratification develops in which the depth of the lower layer decreases as the intensity of the cooling at the ceiling increases. We develop a theoretical model which accounts for the penetrative entrainment across the interface associated with the convection in the upper layer. We show that this becomes more dominant as the cooling increases and eventually the room becomes well-mixed. We discuss the role of such distributed cooling on the design of natural ventilation and its ability to provide sufficient flow and adequate temperature control.
The cascade structure of linear instability in collapsible channel flows
Authors: LUO X. Y. , CAI Z. X. , LI W. G. , PEDLEY T. J.
Published: March 2008

This paper studies the unsteady behaviour and linear stability of the flow in a collapsible channel using a fluid–beam model. The solid mechanics is analysed in a plane strain configuration, in which the principal stretch is defined with a zero initial strain. Two approaches are employed: unsteady numerical simulations solving the nonlinear fully coupled fluid–structure interaction problem; and the corresponding linearized eigenvalue approach solving the Orr–Sommerfeld equations modified by the beam. The two approaches give good agreement with each other in predicting the frequencies and growth rates of the perturbation modes, close to the neutral curves. For a given Reynolds number in the range of 200–600, a cascade of instabilities is discovered as the wall stiffness (or effective tension) is reduced. Under small perturbation to steady solutions for the same Reynolds number, the system loses stability by passing through a succession of unstable zones, with mode number increasing as the wall stiffness is decreased. It is found that this cascade structure can, in principle, be extended to many modes, depending on the parameters. A puzzling ‘tongue’ shaped stable zone in the wall stiffness–Respace turns out to be the zone sandwiched by the mode-2 and mode-3 instabilities. Self-excited oscillations dominated by modes 2–4 are found near their corresponding neutral curves. These modes can also interact and form period-doubling oscillations. Extensive comparisons of the results with existing analytical models are made, and a physical explanation for the cascade structure is proposed.
Stability of a coupled body–vortex system
Authors: KANSO EVA , OSKOUEI BABAK GHAEMI
Published: March 2008

This paper considers the dynamics of a rigid body interacting with point vortices in a perfect fluid. The fluid velocity is obtained using the classical complex variables theory and conformal transformations. The equations of motion of the solid–fluid system are formulated in terms of the solid variables and the position of the point vortices only. These equations are applied to study the dynamic interaction of an elliptic cylinder with vortex pairs because of its relevance to understanding the swimming of fish in an ambient vorticity field. Two families of relative equilibria are found: moving Föppl equilibria; and equilibria along the ellipse's axis of symmetry (the axis perpendicular to the direction of motion). The two families of relative equilibria are similar to those present in the classical problem of flow past a fixed body, but their stability differs significantly from the classical ones.
Mixing efficiency in controlled exchange flows
Authors: PRASTOWO TJIPTO , GRIFFITHS ROSS W. , HUGHES GRAHAM O. , HOGG ANDREW McC.
Published: March 2008

Turbulence and mixing are generated by the shear between two counter-flowing layers in hydraulically controlled buoyancy-driven exchange flows through a constriction. From direct measurements of the density distribution and the amount of turbulent mixing in steady laboratory exchange flows we determine the overall efficiency of the mixing. For sufficiently large Reynolds numbers the mixing efficiency is 0.11(±0.01), independent of the aspect ratio and other details of constriction geometry, in good agreement with a scaling analysis. We conclude that the mixing in shear flows of this type has an overall efficiency significantly less than the maximum value widely proposed for stratified turbulence.
Cognitive and neurobiological alterations in electromagnetic hypersensitive patients: results of a case-control study
Authors: Landgrebe M. , Frick U. , Hauser S. , Langguth B. , Rosner R. , Hajak G. , Eichhammer P.
Published: March 2008

Background

Hypersensitivity to electromagnetic fields (EMF) is frequently claimed to be linked to a variety of non-specific somatic and neuropsychological complaints. Whereas provocation studies often failed to demonstrate a causal relationship between EMF exposure and symptom formation, recent studies point to a complex interplay of neurophysiological and cognitive alterations contributing to symptom manifestation in electromagnetic hypersensitive patients (EHS). However, these studies have examined only small sample sizes or have focused on selected aspects. Therefore this study examined in the largest sample of EHS EMF-specific cognitive correlates, discrimination ability and neurobiological parameters in order to get further insight into the pathophysiology of electromagnetic hypersensitivity.

Method

In a case-control design 89 EHS and 107 age- and gender-matched controls were included in the study. Health status and EMF-specific cognitions were evaluated using standardized questionnaires. Perception thresholds following single transcranial magnetic stimulation (TMS) pulses to the dorsolateral prefrontal cortex were determined using a standardized blinded measurement protocol. Cortical excitability parameters were measured by TMS.

Results

Discrimination ability was significantly reduced in EHS (only 40% of the EHS but 60% of the controls felt no sensation under sham stimulation during the complete series), whereas the perception thresholds for real magnetic pulses were comparable in both groups (median 21% versus 24% of maximum pulse intensity). Intra-cortical facilitation was decreased in younger and increased in older EHS. In addition, typical EMF-related cognitions (aspects of rumination, symptom intolerance, vulnerability and stabilizing self-esteem) specifically differentiated EHS from their controls.

Conclusions

These results demonstrate significant cognitive and neurobiological alterations pointing to a higher genuine individual vulnerability of electromagnetic hypersensitive patients.
Prevalence and sociodemographic correlates of depression in an elderly population living with family members in Beijing, China
Authors: Ma X. , Xiang Y.-T. , Li S.-R. , Xiang Y.-Q. , Guo H.-L. , Hou Y.-Z. , Cai Z.-J. , Li Z.-B. , Li Z.-J. , Tao Y.-F. , Dang W.-M. , Wu X.-M. , Deng J. , Ungvari G. S. , Chiu H. F. K.
Published: March 2008

Background

To date, there has been no large-scale survey of geriatric depression (GD) involving both rural and urban areas in China using standardized assessment tools and diagnostic criteria. This study aimed to determine the 12-month and lifetime prevalence rates of GD and sociodemographic correlates in urban and rural regions of Beijing, China.

Method

A total of 1601 elderly patients (aged ⩾60 years) were randomly selected and interviewed in Beijing using the Composite International Diagnostic Interview (CIDI 1.0). Basic sociodemographic and clinical data were also collected during the interviews.

Results

The overall 12-month prevalence of GD was 4.33%, and the 12-month prevalence rates for men and women were 2.65% and 5.83% respectively. The overall lifetime prevalence of GD was 7.83%, and lifetime prevalence rates for men and women were 4.65% and 10.66% respectively. Female sex, lower educational level, monthly income, rural abode, and the presence of one or more major medical conditions were associated with increased risk of GD. Of the GD subjects interviewed, 25.2% were receiving some type of treatment, with only 4.7% preferring to seek treatment from mental health professionals.

Conclusions

Although still relatively low by international standards, there is an increasing trend in the prevalence of GD in China. The low percentage of subjects treated for GD is a major public health concern that should be addressed urgently.
Ethnicity, socio-economic status and self-harm in Swedish youth: a national cohort study
Authors: Jablonska B. , Lindberg L. , Lindblad F. , Hjern A.
Published: March 2008

Background

Previous studies have shown an elevated risk for self-harm in adolescents from ethnic minorities. However, potential contributions to this risk from socio-economic factors have rarely been addressed. The main aim of this article was to investigate any such effects.

Method

A national cohort of 1009 157 children born during 1973–1982 was followed prospectively from 1991 to 2002 in Swedish national registers. Multivariate Cox analyses of proportional hazards were used to estimate the relative risk of hospital admission for self-harm. Parental country/region of birth was used as proxy for ethnicity.

Results

Youth with two parents born outside Sweden (except those from Southern Europe) had higher age- and gender-adjusted hazard ratios (HRs) of self-harm than the majority population (HR 1.6–2.3). The HRs decreased for all immigrant groups when socio-economic factors were accounted for but remained significantly higher for immigrants from Finland and Western countries and for youth with one Swedish-born and one foreign-born parent.

Conclusions

Socio-economic factors explain much of the variation by parental country of birth of hospital admissions for self-harm in youth in Sweden.