bluuebunny/crossref_metadata_2025 huggingface dataset:
Pregnancy in patients with undifferentiated connective tissue disease: a prospective case-control study
Authors: Castellino G , Capucci R , Bernardi S , Padovan M , Giacuzzo S , Pivato E , Patella A , Trotta F , Govoni M
Published: August 2011

Objectives. To assess the outcome of pregnancy and disease flare or differentiation into well-defined connective tissue disease (CTD), in a cohort of pregnant patients with undifferentiated connective tissue disease (UCTD) and to compare these findings with those obtained from a population of non-pregnant women with UCTD. Methods. In total, 55 pregnancies (in 50 UCTD patients) were monitored from the positive pregnancy test until the sixth month after delivery. Likewise, during a 15-month timeframe, the incidence of flares or evolution into a major CTD was also recorded in a population of 53 non-pregnant women with UCTD. The Student t-test was applied for unpaired, continuous variables and chi-square was applied when percentages were compared. Results. The mean duration of the successful pregnancies was 38.6 weeks (range 28–42) while the mean birth weight was 3190 g (range 1200–4600 g). Three pregnancies (5.4%) ended in miscarriage. The following obstetric complications were found: five premature membrane ruptures, two preeclampsia and two intra-uterine growth restrictions. In a total of 16 patients (32%) the disease flared during pregnancy or during the 6-month post-delivery period. Of these, five developed well-defined CTD after delivery. In the control population, six patients flared (11%) and, of these, only one developed a well-defined CTD. Conclusions. If pregnancy is properly treated, the outcome in UCTD patients is generally good while, considering disease activity, pregnancy appears to be a clear risk factor for flare up or evolution into well-defined CTD.
Cell Death Pathways in Acute Ischemia/Reperfusion Injury
Authors: Gottlieb Roberta A.
Published: August 2011

The consequence of myocardial ischemia is energetic stress, while reperfusion is accompanied by abrupt ionic shifts and considerable oxidative stress. Cells die by apoptotic and necrotic pathways. After the acute injury, the healing myocardium is subject to biomechanical stress and inflammation, which can trigger a smaller but more sustained wave of cell death, as well as changes in the metabolic and functional characteristics of surviving cells. The goal of cardioprotection is to prevent cell death during the acute injury as well as to modulate the detrimental processes that ensue during remodeling. This review will focus on acute injury, and the central premise is that mitochondria are the key determinant of cardiomyocyte fate.
New Pregnane Steroids from Formosan Red Alga Ceratodictyon spongiosum and Symbiotic Sponge Sigmadocia symbiotica
Authors: Lu Chung-Kuang , Wang Shang-Kwei , Duh Chang-Yih
Published: August 2011

Four new pregnane steroids, ceratosteroid A (1), B (2), C (3), and D (4), were isolated from the Formosan red alga Ceratodictyon spongiosum and symbiotic sponge Sigmadocia symbiotica. The structures were elucidated by 1D and 2D NMR spectral analyses. Compounds 2 and 4 showed cytotoxicity against P-388 cell line.
Perfect Numbers with Identical Digits
Authors: Pollack Paul
Published: August 2011

Suppose
Violência familiar contra a criança e perspectivas de intervenção do Programa Saúde da Família: a experiência do PMF/Niterói (RJ, Brasil)
Authors: Rocha Pedro Carlos Xavier da , Moraes Claudia Leite
Published: August 2011

O objetivo do estudo é estimar a prevalência e caracterizar a Violência Familiar contra Crianças (VFC) adscritas ao Programa Médico de Família de Niterói/RJ, discutindo possibilidades de atuação das equipes visando à prevenção, detecção precoce e acompanhamento de famílias em situação de violência. Trata-se de um inquérito de base populacional, com amostra de 278 crianças, selecionadas através de amostragem sistemática, dentre aquelas adscritas a 27 equipes de Saúde da Família. A prevalência de VFC foi estimada utilizando-se a versão nacional da Conflict Tactics Scale Parent-Child (CTSPC). A agressão psicológica ocorreu em 96,7% (IC 95%: 94,7-98,8) dos domicílios. O castigo corporal foi referido por 93,8% (IC 95%: 92,0-96,7) dos respondentes. A violência física menor e a grave foram praticadas por 51,4% (IC 95%: 45,5-57,3) e 19,8% (IC 95%: 15,1-24,5) das famílias, respectivamente. A mãe foi a principal autora de todos os tipos de maus-tratos, embora a maioria das crianças sofra agressões psicológicas e punições corporais por parte de ambos os pais. Diante das altas prevalências e do envolvimento de toda a família nas situações de violência, preconiza-se que o problema seja considerado prioridade na Estratégia Saúde da Família.
Acute toxicity and inactivation tests of CO2 on invertebrates in drinking water treatment systems
Authors: Yin Wen-Chao , Zhang Jin-Song , Liu Li-Jun , Zhao Jian-Shu , Li Tuo
Published: August 2011

In addition to the esthetic problem caused by invertebrates, researchers are recently starting to be more aware of their potential importance in terms of public health. However, the inactivation methods of invertebrates which could proliferate in drinking water treatment systems are not well developed. The objective of this study is to assess the acute toxicity and inactivation effects of CO2 on familiar invertebrates in water treatment processes. The results of this study revealed that CO2 has a definite toxicity to familiar invertebrates. The values of 24-h LC50 (median lethal concentration) were calculated for each test with six groups of invertebrates. The toxicity of CO2 was higher with increasing concentrations in solution but was lower with the increase in size of the invertebrates. Above the concentration of 1,000 mg/L for the CO2 solution, the 100% inactivation time of all the invertebrates was less than 5 s, and in 15 min, the inactivation ratio showed a gradient descent with a decline in concentration. As seen for Mesocyclops thermocyclopoides, by dosing with a sodium bicarbonate solution first and adding a dilute hydrochloric acid solution 5 min later, it is possible to obtain a satisfactory inactivation effect in the GAC (granular activated carbon) filters.
Development and characterization of polymorphic microsatellite markers in Dysosma pleiantha (Berberidaceae)
Authors: Guan Bi‐Cai , Gong Xi , Zhou Shi‐Liang
Published: August 2011

• Premise of the study: The development of compound microsatellite markers was conducted in Dysosma pleiantha to investigate genetic diversity and population genetic structure of this threatened medicinal plant.

• Methods and Results: Using the compound microsatellite marker technique, 14 microsatellite markers that were successfully amplified showed polymorphism when tested on 38 individuals from three populations in eastern China. Overall, the number of alleles per locus ranged from 2 to 14, with an average of 7.71 alleles per locus.

• Conclusions: These results indicate that these microsatellite markers are adequate for detecting and characterizing population genetic structure and genetic diversity in Dysosma pleiantha.
Abdominal Paragangliomas: Analysis of Surgeon's Experience
Authors: FitzGerald SC , M Gingell Littlejohn , Parnaby CN , Connell JM , O'Dwyer PJ
Published: August 2011

Abdominal paraganglioma is a rare endocrine tumor associated with genetic mutations, however, the ability to predict long-term risk of metastasis has not been clarified. The aim of this study was to examine the clinicopathological features and outcomes in patients undergoing surgery for an abdominal paraganglioma. A retrospective analysis was performed for all patients undergoing surgery for abdominal paragangliomas from one surgical department between 1998 and 2010. Clinical presentation, hormone secretion and clinical outcomes were examined. A total of 23 patients underwent surgery for abdominal paraganglioma with the most common presentation being hypertension. Median time to metastasis was 32 months with all patients developing disease progression having a rise in urine catecholamines. Patients with capsular invasion or predisposing genetic conditions are at a higher risk of having more aggressive disease. All patients with a diagnosis of paraganglioma should be screened for predisposing genetic abnormalities and postoperative follow-up must include routine urinary catecholamine assessment.
Garantizando el acceso a la información pública en México: Propuesta para tratamiento de la información del portal de la Secretaria de Salud Federal
Authors: Hernández Landeros José Alfredo
Published: August 2011

Reflexiona sobre la necesidad de garantizar el acceso a la información a toda persona como base fundamental de una sociedad de la información. Presenta el caso de México y sus políticas públicas de información desde el Instituto Federal de Acceso a la Información. Plantea una propuesta para adoptar un sistema de gestión de información documental para la Secretaría de Salud Federal de México, basado en normas y estándares internacionales con el propósito de controlar, organizar y recuperar la información dentro de su sitio web.
Overview of Peroxiredoxins in Oxidant Defense and Redox Regulation
Authors: Poole Leslie B. , Hall Andrea , Nelson Kimberly J.
Published: August 2011

Peroxiredoxins are important hydroperoxide detoxification enzymes, yet have only come to the fore in recent years relative to the other major players in peroxide detoxification, heme‐containing catalases and peroxidases and glutathione peroxidases. These cysteine‐dependent peroxidases exhibit high reactivity with hydrogen peroxide, organic hydroperoxides, and peroxynitrite and play major roles not only in peroxide defense, but also in regulating peroxide‐mediated cell signaling. This overview focuses on important peroxiredoxin features that have emerged over the past several decades with an emphasis on catalytic mechanism, regulation, and biological function.Curr. Protoc. Toxicol. 49:7.9.1‐7.9.15. © 2011 by John Wiley & Sons, Inc.
Electrode Considerations for the Optical Enhancement of Organic Bulk Heterojunction Solar Cells
Authors: Hadipour Afshin , Cheyns David , Heremans Paul , Rand Barry P.
Published: August 2011

In this paper, we consider the optical effects in conventional and inverted bulk heterojunction organic solar cells associated with various electrodes, and perform a systematic study on the anode and cathode buffer layers commonly used in high performance devices. In the devices produced here, we determine that parasitic absorption by low work function metals such as calcium reduces photocurrent by 25%, and that parasitic reflection at interfaces between the transparent conducting oxide and metal oxide buffer layers can reduce photocurrent by more than 10%. We also quantify the impact of an optical spacer, and determine that this accounts for only a fraction of the improvement that can be gained through alternative electrode optimization routes. It is therefore our intention that this study serves as a guideline for the optimization of the electrodes of organic thin film photovoltaic devices.
A novel 4p16.3 microduplication distal to WHSC1 and WHSC2 characterized by oligonucleotide array with new phenotypic features
Authors: Cyr Andrew B. , Nimmakayalu Manjunath , Longmuir Susannah Q. , Patil Shivanand R. , Keppler‐Noreuil Kim M. , Shchelochkov Oleg A.
Published: August 2011

Larger imbalances on chromosome 4p in the form of deletions associated with Wolf–Hirschhorn syndrome (WHS) and duplications of chromosome 4p have a defined clinical phenotype. The critical region for both these clinical disorders has been narrowed based on the genotype–phenotype correlations. However, cryptic rearrangements in this region have been reported infrequently. We report on a male patient with a microduplication of chromosome 4p, who presents with findings of macrocephaly, irregular iris pigmentation‐heterochromia, and preserved linear growth in addition to overlapping features of trisomy 4p such as seizures, delayed psychomotor development, and dysmorphic features including prominent glabella, low‐set ears, and short neck. Using a high‐density oligonucleotide microarray, we have identified a novel submicroscopic duplication involving dosage sensitive genes TACC3, FGFR3, and LETM1. The microduplication did not involve WHSC1 and WHSC2 which are considered in the critical region for WHS and trisomy 4p. This patient's presentation and genomic findings help further delineate clinical significance of re‐arrangements in the 4p16 region without the involvement of WHS critical region. © 2011 Wiley‐Liss, Inc.
Experimental and Theoretical Evidence of Aromatic Behavior in Heterobenzene‐Like Molecules with Metal–Metal Multiple Bonds
Authors: Fang Wenjuan , He Qiao , Tan Zhong Fei , Liu Chun Y. , Lu Xin , Murillo Carlos A.
Published: August 2011

Binding two quadruply bonded dimolybdenum units [Mo2(DAniF)3]+ (DAniF=N,N′‐di‐p‐anisylformamidinate) with two chalcogen atoms generated two molecules with a central core composed of a cyclic six‐membered [Mo2]2(μ‐EH)2 species (E=S in 1 and O in 3, and [Mo2] is a quadruple‐bonded [Mo2(formamidinate)3] unit). Aerobic oxidation of 1 and 3 followed by concomitant deprotonation gave rise to the corresponding [Mo2]2(μ‐E)2 compounds 2 and 4. The latter show a striking coplanarity and near‐bond equalization of the Mo/E cluster. The oxidized species 2 and 4 are diamagnetic in the measured temperature range of 5 to 300 K, which is somewhat unexpected for molecules that have dimetal units with a σ2π4δ1 electronic configuration. This suggests there are strong interactions between the dimolybdenum units through the E atoms. The large electronic delocalization of the δ electrons over the entire Mo/E core is supported by the exceptionally large potential separation for the two successive one‐electron reductions of the linked Mo25+ units from the oxidized species (ΔE1/2=1.7 V for the sulfur analogue). This large electronic delocalization has an important effect on the NMR spectroscopic signals for the two sets of methine (N‐(CH)‐N) protons from the DAniF ligands. Those essentially parallel to the core, H∥, and those essentially perpendicular to the core, H⊥, exhibit downfield and upfield chemical shifts, respectively, that are separated by δ=1.32 ppm. The structural, electronic, magnetic, and chemical behaviors for 2 and 4 are consistent with aromaticity, with the [Mo2E2Mo2] cores that resemble the prototypical benzene molecule. Theoretical studies, including DFT calculations, natural bond orbital (NBO) analyses, and gauge‐independent atomic orbital (GIAO) NMR spectroscopic calculations, are also consistent with the aromaticity of the [Mo2]2(μ‐E)2 units being promoted by dδ(Mo2)–pπ(E) π conjugation. The cyclic π conjugation of the central moiety in 2 and 4 involves a total of six electrons with 2e from δ(Mo2) and 4e from pπ(E) orbitals, thereby conforming to Hückel’s rule when electrons in the MOs with δ character are considered part of the delocalized system.
Thermal Activation of Methane and Ethene by Bare MO.+ (M=Ge, Sn, and Pb): A Combined Theoretical/Experimental Study
Authors: Chen Kai , Wang Zhe‐Chen , Schlangen Maria , Wu Yun‐Dong , Zhang Xinhao , Schwarz Helmut
Published: August 2011

The thermal ion/molecule reactions (IMRs) of the Group 14 metal oxide radical cations MO.+ (M=Ge, Sn, Pb) with methane and ethene were investigated. For the MO.+/CH4 couples abstraction of a hydrogen atom to form MOH+ and a methyl radical constitutes the sole channel. The nearly barrier‐free process, combined with a large exothermicity as revealed by density functional theory (DFT) calculations, suggests a fast and efficient reaction in agreement with the experiment. For the IMR of MO.+ with ethene, two competitive channels exist: hydrogen‐atom abstraction (HAA) from and oxygen‐atom transfer (OAT) to the organic substrate. The HAA channel, yielding C2H3. and MOH+ predominates for the GeO.+/ethene system, while for SnO.+ and PbO.+ the major reaction observed corresponds to the OAT producing M+ and C2H4O. The DFT‐derived potential‐energy surfaces are consistent with the experimental findings. The behavior of the metal oxide cations towards ethene can be explained in terms of the bond dissociation energies (BDEs) of MO+H and M+O, which define the hydrogen‐atom affinity of MO+ and the oxophilicity of M+, respectively. Since the differences among the BDEs(MO+H) are rather small and the hydrogen‐atom affinities of the three radical cations MO.+ exceed the BDE(CH3H) and BDE(C2H3H), hydrogen‐atom abstraction is possible thermochemically. In contrast, the BDEs(M+O) vary quite substantially; consequently, the OAT channel becomes energetically less favorable for GeO.+ which exhibits the highest oxophilicity among these three group 14 metal ions.
Theoretical analysis of thermal radiative equilibrium via a radiosity method
Authors: Kondo Yoshio , Yamashita Hiroshi
Published: August 2011

We propose a theoretical consideration of thermal radiative equilibrium via a radiosity method. According to G. Kirchhoff's research on cavity radiation, the condition of radiative equilibrium arises in a cavity in which the internal wall temperature is uniform. Furthermore, by considering the balance of energy on the wall surfaces in the cavity, the relationship, emittance ϵ = absorptance α, is obtained. Adversely, in the present study, we developed a method to prove the conclusion of the uniformity and uniqueness of radiative equilibrium in the cavity (independent of the emittance of the interior wall surfaces) by considering the relationship ϵ = α on the wall surfaces to be a supposition. Using the concept of radiosity, we proved that the radiosities on the internal wall surfaces can be kept uniform in the enclosed system of thermal radiative equilibrium. This knowledge is advantageous for inspecting the benchmarks of various programs for radiative analysis. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20372
A putative role for c-Fos in the pathophysiology of paget's disease
Authors: Beedles Karen E. , Sharpe Paul T. , Wagner Erwin F. , Dr. Grigoriadis Agamemnon E.
Published: August 2011

The molecular mechanisms underlying Paget's disease and subsequent osteosarcoma formation are not well understood. In this study, we aim to delineate the function of the c-Fos oncogene in Paget's disease using transgenic mice, based on previous findings that c-Fos is highly expressed in Pagetic osteoclasts and that c-Fos is an essential gene for osteoclast differentiation and skeletal neoplasia. We have generated transgenic mice in which c-Fos is overexpressed specifically in osteoclasts using the tartrate-resistant acid phosphatase (TRAP) promoter, and five founder mice have been identified. All transgene-expressing animals developed severe bone remodeling lesions, some of which progressed to large bone tumors. Histopathologic analysis indicated that the lesions contained a marked increase in the number of osteoclasts that contained a large number of nuclei. Osteoclasts were identified by histochemical staining for TRAP and by in situ hybridization for matrix metalloproteinase-9 (MMP-9) expression. Moreover, transgenic osteoclasts, and in some cases, osteoblasts and chondrocytes, expressed high levels of c-Fos protein as judged by immunocytochemistry. This phenotype of increased osteoclast number and activity, together with an apparently high rate of bone turnover, resembles some characteristics of Paget's disease. These data therefore support an important function for c-Fos in the Pagetic phenotype, and further support the notion that this gene is important in osteoclastogenesis and in bone remodeling disorders.
Notch signaling components are upregulated during both endochondral and intramembranous bone regeneration
Authors: Dishowitz Michael I. , Terkhorn Shawn P. , Bostic Sandra A. , Hankenson Kurt D.
Published: August 2011

Previous studies have demonstrated that Notch signaling regulates endochondral and intramembranous bone formation by controlling cell proliferation and differentiation. Notch signaling has also been shown to regulate healing in a variety of tissues. The objective of this study was to characterize and compare activation of the Notch signaling pathway during endochondral and intramembranous bone healing using tibial fracture and calvarial defect injury models, respectively. Bilateral tibial fractures or bilateral 1.5 mm diameter calvarial defects were created in mice, and tissues were harvested at 0, 5, 10, and 20 days post‐fracture. Gene expression of Notch signaling components was upregulated during both tibial fracture and calvarial defect healing, with expression generally higher during tibial fracture healing. The most highly expressed ligand and receptor during healing, Jag1 and Notch2 (specifically the activated receptor, known as NICD2), were similarly localized in mesenchymal cells during both modes of healing, with expression decreasing during chondrogenesis, but remaining present in osteoblasts at all stages of maturity. Results suggest that in addition to embryological bone development, Notch signaling regulates both endochondral and intramembranous bone healing. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:296–303, 2012
Effects of ripening, 1‐methylcyclopropene and ultra‐high‐pressure pasteurisation on the change of volatiles in Chinese pear cultivars
Authors: Kou Xiaohong , Liu Xiangping , Li Jiangkuo , Xiao Huazhi , Wang Jiehua
Published: August 2011

BACKGROUND: Aroma is one important fruit sensory attribute influenced by the volatile constituents related to species, variety and technological treatments. We analysed the variations of volatile compounds in five pear cultivars and investigated their changes related to different pear organs, different ripening stages, 1‐MCP treatment and ultra‐high‐pressure pasteurisation.

RESULTS: Considerable variations exist in the quantity of 10 volatile compounds among five pear cultivars. Their levels generally showed an increasing trend when collected at later harvest time in Ya pear. In Whangkeumbae pear, most volatile compounds reached their maximum levels in skin and pulp. After treating pears with 42 µmol L−1 1‐methylcyclopropene (1‐MCP), the levels of volatiles remained basically unchanged or only slightly increased in Ya pear during a shelf life of 21 days. When Huangguan pear juice was pasteurised by using ultra‐high pressure, the levels of volatiles significantly changed during the shelf life.

CONCLUSION: The volatile compositions of five different Chinese pear cultivars differ considerably. The levels of these volatiles vary along with ripening stages and pear tissues. A moderate concentration of 1‐MCP could keep the levels of volatile compounds basically unchanged during storage and ultra‐high‐pressure pasteurisation could change the levels of volatiles significantly during the following shelf life. Copyright © 2011 Society of Chemical Industry
Expression of modified tocopherol content and profile in sunflower tissues
Authors: Del Moral Lidia , Fernández‐Martínez José M , Pérez‐Vich Begoña , Velasco Leonardo
Published: August 2011

BACKGROUND: Alpha‐tocopherol is the predominant tocopherol form in sunflower seeds. Sunflower lines that accumulate increased levels of beta‐, gamma‐ and delta‐tocopherol in seeds as well as lines with reduced and increased total seed tocopherol content have been developed. The objective of this research was to evaluate whether the modified tocopherol levels are expressed in plant tissues other than seeds.

RESULTS: Lines with increased levels of beta‐, gamma‐ and delta‐tocopherol in seeds also possessed increased levels of these tocopherols in leaves, roots and pollen. Correlation coefficients for the proportion of individual tocopherols in different plant tissues were significantly positive in all cases, ranging from 0.68 to 0.97. A line with reduced tocopherol content in seeds also showed reduced content in roots and pollen.

CONCLUSION: Genetic modifications producing altered seed tocopherol profiles in sunflower are also expressed in leaves, roots and pollen. Reduced total seed tocopherol content is mainly expressed at the root and pollen level. The expression of tocopherol mutations in other plant tissues will enable further studies on the physiological role of tocopherols and could be of interest for early selection for these traits in breeding programmes. Copyright © 2011 Society of Chemical Industry
Quantitative descriptive analysis of Italian polenta produced with different corn cultivars
Authors: Zeppa Giuseppe , Bertolino Marta , Rolle Luca
Published: August 2011

BACKGROUND: Polenta is a porridge‐like dish, generally made by mixing cornmeal with salt water and stirring constantly while cooking over a low heat. It can be eaten plain, straight from the pan, or topped with various foods (cheeses, meat, sausages, fish, etc.). It is most popular in northern Italy but can also be found in Switzerland, Austria, Croatia, Argentina and other countries in Eastern Europe and South America. Despite this diffusion, there are no data concerning the sensory characteristics of this product. A research study was therefore carried out to define the lexicon for a sensory profile of polenta and relationships with corn cultivars.

RESULTS: A lexicon with 13 sensory parameters was defined and validated before references were determined. After panel training, the sensory profiles of 12 autochthonous maize cultivars were defined.

CONCLUSION: The results of this research highlighted that quantitative descriptive analysis can also be used for the sensory description of polenta, and that the defined lexicon can be used to describe the sensory qualities of polenta for both basic research, such as maize selection, and product development. Copyright © 2011 Society of Chemical Industry
Doubly Hydrophilic Multiarm Hyperbranched Polymers with Acylhydrazone Linkages as Acid‐Sensitive Drug Carriers
Authors: Wang Qiang , Zhu Lijuan , Li Guolin , Tu Chunlai , Pang Yan , Jin Chengyu , Zhu Bangshang , Zhu Xinyuan , Liu Yingqun
Published: August 2011

A novel type of drug carrier capable of controlled drug release is proposed. It consists of an acid‐sensitive doubly hydrophilic multiarm hyperbranched copolymer with a hyperbranched polyamidoamine core and many linear poly(ethylene glycol) arms. Using pH‐sensitive acylhydrazone linkages, the polymer forms unimolecular micelles that can encapsulate hydrophobic drugs. Due to their amphiphilicity, the drug‐loaded unimolecular micelles can self‐assemble into multimolecular micelles that show acid‐triggered intracellular delivery of the hydrophobic drugs.

magnified image
Application of diffusion‐edited NMR spectroscopy for selective suppression of water signal in the determination of monomer composition in alginates
Authors: Vilén Eric Morssing , Klinger Markus , Sandström Corine
Published: August 2011

Alginate is a linear copolymer of 1‐4 linked β‐D‐mannuronic acid (M) and 1‐4 linked α‐L‐guluronic acid (G). The physical properties of these polysaccharides such as gel properties and viscosity are largely correlated to the monomer composition (M/G ratio), the sequence of the polymer and the molecular weight. Determination of the M/G ratio is therefore important and NMR spectroscopy is among the most common methods used to accurately obtain this ratio. Instead of using time consuming, possibly sample altering, acid hydrolysis to reduce the viscosity of the alginate sample prior to analysis, samples of low concentrations can be used. However, this results in a water peak in the NMR spectrum that is several orders of magnitude larger than the alginate signals and water suppression is required. In this article, a diffusion‐edited NMR experiment that suppresses the water peak while retaining the signals of interest has been used to enable correct M/G ratio determination. This approach exploits the difference in translational diffusion between the larger alginate molecules and the smaller water molecules. Using this method, the monomer composition of 20 different alginate powders was determined. The diffusion parameters were optimized to allow measurement for samples covering a large range of M/G ratios and viscosities. Thus, such method should be useful for analyzing large numbers of unknown alginate samples using, for example, automation procedures. Copyright © 2011 John Wiley & Sons, Ltd.
An investigation of glass–fiber reinforced polyamide 66 during conditioning in various automotive fluids
Authors: Thomason James L. , Porteus Glen
Published: August 2011

Injection molded glass–fiber reinforced polyamide 66 composites and unreinforced polymer samples have been characterized during conditioning up to 900 h in water, ethylene glycol, and water–glycol mixture at 50 and 70°C. All materials showed significant fluid and temperature‐dependent weight and volume increase. Glass reinforcement significantly reduced the polymer fluid uptake. The absorption of the antifreeze mixture initially follows a simple rule of mixtures of the absorption of the two individual components. However, after absorption of ∼5% a significantly higher than predicted level of antifreeze absorption was observed. This coincided with a significant increase in the volumetric swelling coefficient. Dynamic mechanical analysis and unnotched impact testing indicated significant changes in composite mechanical performance dependent on conditioning fluid and temperature. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Uniform star‐polystyrene nanoparticles prepared by emulsion atom transfer radical polymerization
Authors: Wang Wenhao , Liu Hu , Hu Xiaoxi , Yi Changfeng , Wu Shuilin , Chu Paul K , Xu Zushun
Published: August 2011

Pentaerythritol (PT) was converted into four‐arm initiator pentaerythritol tetrakis(2‐chloropropionyl) (PT‐Cl) via reaction with 2‐chloropropionyl chloride. Uniform (monodisperse) star‐polystyrene nanoparticles were prepared by emulsion atom transfer radical polymerization of styrene, using PT‐Cl/CuCl/bpy (bpy is 2,2′‐dipyridyl) as the initiating system. The structures of PT‐Cl and polymer were characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The morphology, size and size distribution of the star‐polystyrene nanoparticles were characterized by transmission electron microscopy, atomic force microscopy and photon correlation spectroscopy. It was found that the average diameters of star‐polystyrene nanoparticles were smaller than 100 nm (30–90 nm) and monodisperse; moreover, the particle size could be controlled by the monomer/initiator ratio and the surfactant concentration. The average hydrodynamic diameter (Dh) of the nanoparticles increased gradually on increasing the ratio of styrene to PT‐Cl and decreased on enhancing the surfactant concentration or increasing the catalyst concentration. Copyright © 2011 Society of Chemical Industry
Soil charcoal stability over the Holocene across boreal northeastern North America
Authors: de Lafontaine Guillaume , Asselin Hugo
Published: August 2011

The analysis of macroscopic wood charcoal fragments extracted from soils is frequently used as a palaeoecological tool for reconstructing stand-scale forest composition and fire history. Here we explored the putative loss of palaeoecological information due to charcoal degradation through time and in different biogeographical settings. We compared the relationship between charcoal mass and abundance for soil samples from five biogeographical regions of boreal northeastern North America spanning most of the Holocene period. We verified whether charcoal (Ø ≥ 2 mm) conservation differed as a consequence of different taphonomical processes between organic and mineral soil types. We also assessed the mass/abundance relationship as a function of charcoal residence time in soil. Overall, the slope of the regression between charcoal particles mass (g) and abundance (number of particles) was 0.0042. The slope was not significantly different in samples from organic and mineral soil, and all biogeographical regions had similar slope values except one (higher charcoal fragmentation, probably due to high colluvial activity). Charcoal conservation also did not vary according to residence time in soil. This study shows that macroscopic soil charcoal particles resist fragmentation over millennia in different biogeographical settings and under the influence of various taphonomical processes.
Optical guiding in a plasma channel having top-hat refractive index radial profile
Authors: SOHBATZADEH F. , MIRZANEJHAD S. , GHALANDARI M.
Published: August 2011

In this paper, intense laser pulse guiding through a weakly ionized plasma channel is studied numerically. The radial profile of the channel refractive index is assumed to be top-hat. The propagating intense laser pulses are Gaussian TEM00 and Laguerre–Gaussian LG01 modes. The analysis includes the effects of plasma density inhomogeneity, diffraction, further ionization by the propagating laser pulse and nonlinearity arising from the nonlinear Kerr effect. Matched conditions are obtained for both TEM00 and LG01 laser modes for a top-hat refractive index profile. It is seen that the electron density profile changes the matched condition in the transmission of the laser pulse through the plasma channel. It is also shown that the nonlinear Kerr effect changes the matched condition and becomes the dominant effect in intense laser pulse propagation through the weakly ionized plasma channel.
A Staged Fright: Musical Hybridity and Religious Intolerance in Turkey, 1923–38
Authors: O'CONNELL JOHN MORGAN
Published: August 2011

This article is concerned with the relationship between musical style and religious prejudice in Turkey during the early Republican period (1923–38). It focuses on a musical contest in 1932 between a Jewish cantor (hazan) and an Islamic vocalist (hafız) in the presence of Mustafa Kemal Atatürk (1881–1938), the president of the Turkish Republic who instigated revolutionary reforms that affected many aspects of Turkish culture, including music. Historical accounts of this musical contest not only suggest how religious discrimination manifested itself in a competitive setting but also serve to question the parameters of religious tolerance in Turkey, a country often admired for its favourable attitude towards Jews during the twentieth century. The discussion draws on Homi Bhabha's concept of a ‘third space’ to uncover the complex relations that existed in Turkey between Jews and Muslims on the one hand and among Jews on the other. It also invokes Bhabha to show how music can be viewed as a ‘supplementary discourse’ that serves both to unify cultural interests and to perpetuate cultural differences. By challenging the accepted narrative of religious tolerance in historical sources, the article explores through music the characteristics and consequences of racism in the country during a period of growing anti-Semitism both at home and abroad.
Relation of Left Ventricular Mass to QTc in Normotensive Severely Obese Patients
Authors: Mukerji Rita , Terry Boyd E. , Fresen John L. , Petruc Marius , Govindarajan Gurushankar , Alpert Martin A.
Published: August 2011

Prolongation of the corrected QT interval (QTc) has been described in obese subjects. This study assesses the relation of left ventricular (LV) mass to QTc in normotensive severely obese subjects. Fifty normotensive patients whose BMI was ≥40 kg/m2 (mean age: 38 ± 7 years) were studied. QTc was derived using Bazett's formula. LV mass was calculated using the formula of Devereux et al. and was indexed to height2.7. Mean QTc was 428.8 ± 19.0 ms and was significantly longer in those with than in those without LV hypertrophy (P < 0.01) QTc correlated positively and significantly with BMI (r = 0.392, P < 0.025), LV mass/height2.7 (r = 0.793, P < 0.0005), systolic blood pressure (r = 0.742, P < 0.001), LV end — systolic wall stress (r = 0.746, P < 0.001) and LV internal dimension in diastole (r = 0.788, P < 0.0005). Among five variables tested, LV mass/height2.7 was identified as the sole predictor of QTc by multivariate analysis. In conclusion, LV mass and loading conditions that may affect LV mass are important determinants of QTc in normotensive severely obese subjects.
Doping effects of C, Si and Ge in wurtzite [0001] GaN, AlN, and InN nanowires
Authors: Colussi M. L. , Baierle R. J. , Miwa R. H.
Published: August 2011

We have performed an ab initio investigation, within the spin-polarized density functional theory, of the energetic stability and electronic properties of substitutional Si, Ge, and C impurities in [0001] GaN, AlN, and InN nanowires (NWs). Our total energy results show that C impurities in the cation site (CGa, CAl, and CIn) present lower formation energies at the surface of the NWs as compared to their counterparts in the core of the NW or the bulk system. In these position donor likely properties are obtained for GaN and InN NWs, whereas for the AlN NW deep levels are observed inside the bandgap. In contrast, CN must be distributed uniformly along the NW diameter and gives rise to a deep electronic level inside the NW bandgap. Si in GaN and InN and Ge in InN are most stable at the cation site in the core of the NWs, and lead the systems to show a n-type semiconductor properties. For the AlN NW we obtain that Si and Ge are most likely in a N site at the surface of the NW and introduce deep levels inside the NW bandgap. Meanwhile, C and Ge impurities are amphoteric impurities in GaN NWs.
Local electronic structure analysis for brownmillerite Ca(Sr)FeO2.5 using site-resolved energy-loss near-edge structures
Authors: Haruta M. , Kurata H. , Matsumoto K. , Inoue S. , Shimakawa Y. , Isoda S.
Published: August 2011

Oxygen K-edge and Fe L2,3-edge electron energy-loss near-edge structures (ELNES) were measured for FeO6 octahedra and FeO4 tetrahedra in the brownmillerite Ca(Sr)FeO2.5 by focusing an electron probe at individual Fe sites using scanning transmission electron microscopy combined with electron energy-loss spectroscopy. The observed site-resolved oxygen K-ELNES showed different features reflecting the local chemical bonding around the FeO6 octahedra and FeO4 tetrahedra. A pre-peak in the O K-edge spectra, which is attributed to a transition to an unoccupied O 2p band hybridized with the Fe-3d band, shows splitting in the spectrum of the FeO6 octahedral site. Additionally, for the oxygen linking the octahedral and tetrahedral Fe sites in CaFeO2.5, charge transfer was found to preferentially occur toward the tetrahedral Fe ions. In the case of SrFeO2.5, charge transfer from the oxygen located in the ac plane was biased toward the tetrahedral Fe atoms. Based upon an analysis of the pre-peak intensity of the O K-ELNES, it was concluded that bonding between the oxygen and iron atoms at the tetrahedral site was more covalent in character than at the octahedral site. The strong covalent character of the tetrahedral sites would be one of the reasons for distortion in the FeO6 octahedra in Ca(Sr)FeO2.5, as exhibited by an extension along the b-axis.
Time-resolved spectroscopy of plasma plumes: A versatile approach for optimization of high-order harmonic generation in laser plasma
Authors: Ganeev R. A. , Elouga Bom L. B. , Ozaki T.
Published: August 2011

The time-resolved studies of laser-produced Ag, In, Pt, V, Mn, and Ga plasmas are presented from the point of view of plasma application as the nonlinear optical medium for high-order harmonic generation of laser radiation. We show that optimization of plasma formation using this technique allows the enhancement of harmonic generation efficiency and extension of maximal harmonic order.
Void dynamics in copper-based interconnects
Authors: Choi Zung-Sun , Lee Junghoon , Lim Meng Keong , Gan Chee Lip , Thompson Carl V.
Published: August 2011

The electromigration lifetimes of Cu-based interconnects are strongly influenced by whether voids are present before electromigration, and by where fatal voids initially form and grow. Modeling, simulations, and comparisons with in situ experiments are used to establish criteria for void formation away from the cathode end of a copper interconnect. It is shown that observation of voids at locations other than the cathode strongly suggests that the voids grew from pre-existing voids. When pre-existing voids are within a current-density-dependent critical length from the cathode, new voids are unlikely to nucleate at the cathode and failure occurs only when the pre-existing voids grow. As these voids grow, they will either lead directly to open-circuit failure or, once they reach a critical size, they will de-pin from grain boundaries and drift toward the cathode. In the latter case, multiple voids might accumulate and coalesce to cause failure. This mechanism has been observed in both side-view and top-down in situ accelerated life-time testing. It is shown that the relative importance of these various void-induced failure mechanisms depends on the current density, and is different under typical accelerated test conditions from what is expected at service conditions.
Strong red emission in lead-free ferroelectric Pr3+-doped Na0.5Bi0.5TiO3 thin films without the need of charge compensation
Authors: Zhou Hong , Liu Xiang , Qin Ni , Bao Dinghua
Published: August 2011

We report on the strong red emission properties of lead-free perovskite ferroelectric Pr3+-doped Na0.5Bi0.5TiO3 (NBT: Pr3+) thin films without the need of charge compensation. The thin films were prepared by a chemical solution deposition method combined with a rapid thermal annealing process at 700 °C. The strong red emission assigned to prominent 1D2→3H4 transitions of the Pr3+ ions at 611 nm was observed together with a very weak blue-green emission, indicating the commercial use potential of the lead-free perovskite NBT: Pr3+ ferroelectric thin film materials. The energy transfer from the host lattice to the Pr3+ ions should be responsible for the strong red emission, while the weak blue-green emission might be due to the quenching of 3P0 induced by a low-lying Pr3+/Ti4+↔Pr4+/Ti3+ intervalence charge transfer state. The lead-free NBT: Pr3+ thin films also exhibit good ferroelectric and dielectric properties.
Three-dimensional diamagnetic particle deflection in ferrofluid microchannel flows
Authors: Liang Litao , Zhu Junjie , Xuan Xiangchun
Published: August 2011

Magnetic field-induced particle manipulation is a promising technique for biomicrofluidics applications. It is simple, cheap, and also free of fluid heating issues that accompany other common electric, acoustic, and optical methods. This work presents a fundamental study of diamagnetic particle motion in ferrofluid flows through a rectangular microchannel with a nearby permanent magnet. Due to their negligible magnetization relative to the ferrofluid, diamagnetic particles experience negative magnetophoresis and are repelled away from the magnet. The result is a three-dimensionally focused particle stream flowing near the bottom outer corner of the microchannel that is the farthest to the center of the magnet and hence has the smallest magnetic field. The effects of the particle’s relative position to the magnet, particle size, ferrofluid flow rate, and concentration on this three-dimensional diamagnetic particle deflection are systematically studied. The obtained experimental results agree quantitatively with the predictions of a three-dimensional analytical model.
Meissner effect funneling
Authors: McNeil S. P. , Weber M. H. , Lynn K. G.
Published: August 2011

Focusing of a positron beam in a magnetic field funnel is demonstrated using a preferentially-cooled pure niobium single crystal into the superconductor region. A magnetic field increase of 18% was indirectly measured through a hole in a cylindrical niobium sample. The results demonstrate a charged particle beam focusing technique. The results have implications for the brightness enhancement of positron beams and trap-based beams.
Highly conductive and transparent alumina-doped ZnO films processed by direct pulsed laser recrystallization at room temperature
Authors: Zhang Martin Y. , Cheng Gary J.
Published: August 2011

Highly conductive and transparent alumina-doped ZnO (AZO) thin films (250 nm) are deposited at room temperature using pulsed laser deposition (PLD) and direct pulsed laser recrystallization (DPLR). Morphological characterizations show that the AZO films undergo recrystallization and growth during DPLR, which leads to less internal imperfections in AZO films and hence better film conductance. Electrical-optical characterizations show that DPLR results in significant improvement in conductivity, Hall mobility, and transmission from UV to NIR regions. Decrease in carrier concentration density in AZO film is observed. Compared with PLD, DPLR processed AZO films also possess smaller band gap which leads to broader solar spectrum acceptance.
High resolution photoemission and x-ray absorption spectroscopy of a lepidocrocite-like TiO2 nanosheet on Pt(110) (1 × 2)
Authors: Walle L. E. , Agnoli S. , Svenum I.-H. , Borg A. , Artiglia L. , Krüger P. , Sandell A. , Granozzi G.
Published: August 2011

The electronic structure of TiO2 nanosheets on the Pt(110)-(1 × 2) surface has been investigated by using high resolution photoemission spectroscopy and x-ray absorption spectroscopy (XAS). The Ti 2p XAS spectra of the deposited TiO2 films have been theoretically evaluated and, from the comparison with the experimental data, the assignment to a lepidocrocite-like structure is confirmed. Coexistence of TiO2 islands with PtO2 stripes for incomplete nanosheets is confirmed by high resolution photoemission data. The location of the valence and conduction band edges of the nanosheet has been experimentally determined allowing us to describe in details subtle electronic effects due to the interface with the substrate. The locations of the valence band maximum and the leading peak in the O 1s XAS spectrum indicate a band gap similar to anatase but with the Fermi level closer to mid-gap than found for bulk, n-type TiO2.
Optically activated core flow shifting within a focused flow
Authors: Lou Janet W. , Villarruel Carl A. , Schermer Ross T.
Published: August 2011

We report on the application of an optical beam to redirect sheathed micro-fluidic flow without direct interaction with the sample. The hydrodynamic properties of the sheath are locally modified due to optical heating, resulting in a spatial shift of the sample flow. We characterize this technique for a range of flow rates and demonstrate up to 100 μm shift at peak flow velocities of 19 mm/s. We also model the temperature and viscosity changes, as well as the flow velocity profiles for a two-fluid flow with different viscosities. The calculated shifts in the flow profile correspond well with the measured shifts.
Ferroelectric phase transition in polycrystalline KTaO3 thin film revealed by terahertz spectroscopy
Authors: Skoromets V. , Glinšek S. , Bovtun V. , Kempa M. , Petzelt J. , Kamba S. , Malič B. , Kosec M. , Kužel P.
Published: August 2011

KTaO3 single crystal is an archetypal incipient ferroelectric in which a long-range ferroelectric order does not establish at low temperatures owing to quantum fluctuations. We report on a strong evidence of the ferroelectric phase transition near 60 K revealed by terahertz spectroscopy and microwave permittivity measurements of a polycrystalline KTaO3 thin film on (0001) sapphire substrate prepared by chemical solution deposition. The soft mode behavior is clearly observed in the terahertz (THz) spectra with a minimum frequency at 60 K. At the same temperature microwave permittivity maximum appears. The THz spectra strongly resemble that of strained epitaxial SrTiO3/DyScO3 films: the ferroelectric soft mode is linearly coupled to a central peak which is silent in the paraelectric phase and it becomes coupled to the polarization below the ferroelectric transition temperature with a progressively increasing bare strength.