bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanochemical Synthesis of Nanocrystalline (Fe,Co)3О4-Based Alloys and their Magnetic Properties
Authors: Menushenkov Vladimir P. , Yagodkin Yurii D. , Shandrovskaiy Ekaterina
Published: April 2011

The structure of nanocrystalline Fe-Co-O alloys produced by high-energy ball milling and subsequent low-temperature annealing were investigated by X-ray diffraction analysis, scanning and transmission electron microscopy. The magnetic properties were measured in vibrating sample magnetometers at room temperature. The mixtures of FeO and Co powders were used as starting materials. The nanocrystalline composite alloys, obtained as a result of the milling, contained FeO and -Fe with the crystallite size of 12-18 nm as well as an amorphous phase. However, alloys subjected to subsequent annealing contained Fe3O4 and -Fe phases with crystallite size of 10-30 nm, in which Co is dissolved. Unlike the starting materials the produced powders exhibit properties typical of magnetically hard alloys. The intrinsic coercive force of the annealed powders increases with increasing (Fe,Co)3O4 phase content and reaches approximately 800 Oe.
Migrating ground glass opacities on computed tomography due to gravitation in a patient with pulmonary alveolar proteinosis
Authors: Ichihara Eiki , Takigawa Nagio , Kato Katsuya , Tanimoto Yasushi , Yamadori Ichiroh , Kiura Katsuyuki , Tanimoto Mitsune
Published: April 2011

An 80-year-old man presented with heterogeneous ground glass opacity, with interlobular septal thickening in the left lower lobe. The histology of a surgical lung biopsy showed alveolar proteinosis. Computed tomography revealed that the ground glass opacity and interlobular septal thickening observed dorsally in the supine position migrated to the ventral side in the prone position. To the best of our knowledge, this is the first report of a posture-dependent migrating shadow in a patient with pulmonary alveolar proteinosis.
Completely Extruded Talus without Soft Tissue Attachments
Authors: Choi Young Rak , Jeong Jae Jung , Lee Ho Seong , Kim Sang Woo , Suh Jin-Soo
Published: April 2011

A completely extruded talus without any remaining soft tissue attachments is extremely rare. The present report describes treatment of a 45-year-old man who sustained a completely extruded talus injury following a rockclimbing fall. Upon admission, the extruded talus was deep-frozen in our bone bank. The open ankle joint underwent massive wound debridement and irrigation for 3 days. Four days later we performed a primary subtalar fusion between the extruded talus and the calcaneus, anticipating revascularization from the calcaneus. However, aseptic loosening and osteolysis developed around the screw and talus. At 12 months post-trauma we performed a tibiocalcaneal ankle fusion with a femoral head allograft to fill the talar defect. Follow-up at 24 months post-trauma showed the patient had midfoot motion, tibio-talar-calcaneal fusion, and was able partake in 4-hour physical activity twice per week.
An Inside Story of a Thrombosed Pile
Authors: Kumar Yashwant , Bhatia Alka
Published: April 2011

We report a case of extremely rare variant of ano-rectum malignant tumor. The tumor is often misdiagnosed as either hemorrhoids or rectal polyp, which are benign diseases. On histology also this variant may be confused with other more commonly occurring spindle cell lesions in this area; its recognition is therefore important as it normally has a poor prognosis.
Urinary Tract Infection Mimicking Acute Mesenteric Ischaemia in an Immunocompromised Patient
Authors: Hanna Thomas , Powys-Lybbe James , Akoh Jacob A.
Published: April 2011

Bowel infarction due to acute mesenteric ischaemia (AMI) is an abdominal emergency with a high mortality rate. We report a case of exaggerated septic response to a urinary tract infection mimicking AMI in an immunosuppressed diabetic patient. A 56-year-old female was found collapsed at home with a 24 hour history of diarrhoea, a central abdominal pain and a complex past medical history. Examination showed her to be pyrexial, drowsy, profoundly dehydrated with evidence of cardiovascular collapse. She had a tender distended abdomen, raised inflammatory markers, raised lactate of 9.1 u/L and urinalysis was positive for leucocytes and nitrites. An abdominal computed tomography (CT) scan was reported to show small bowel ischaemia. She underwent a negative laparotomy and recovered following management in the intensive therapy unit. The negative laparotomy rate can be reduced by having abdominal CT performed and reported by an experienced radiologist or by the use of diagnostic laparoscopy.
Empreendorismo no Brasil: situação e tendências
Authors: Campelli Magali Geovana Ramlow , Casarotto Filho Nelson , Barbejat Myriam Eugênia Ramalho Prata , Moritz Gilberto de Oliveira
Published: April 2011

Este artigo apresenta as tendências do empreendedorismo no Brasil. Neste trabalho são destacadas as iniciativas adotadas no País com enfoque para a avaliação dos resultados produzidos pelo programa Empretec e o desempenho apontado pelos relatórios do Global Entrepreneurship Monitor – GEM. Temas recentes também são introduzidos no cenário atual,  tais como,  o empreendedorismo social e o educacional.
A influência das condições do mercado acionário e da política monetária no comportamento dos indicadores de risco tamanho, índice book-to-market e momento, no mercado acionário brasileiro
Authors: Mussa Adriano , Securato José Roberto , Dos Santos José Odálio , Famá Rubens
Published: April 2011

Nos últimos anos têm se intensificado na literatura nacional e internacional os testes empíricos de modelos APT (ArbitragePricingTheory) para a precificação de ativos, principalmente com o uso de características da empresa para a formação de fatores de risco adicionais ao beta de mercado. Os modelos 3-fatores de Fama &French e 4-fatores de Carhart são dois exemplos recorrentemente testados desse tipo de modelo, com evidências de relativo sucesso. Diante desse cenário, torna-se importante aprofundar os estudos sobre o comportamento dos fatores de risco que compõem esses modelos. Seguindo o caminho de pesquisas internacionais, o objetivo do presente trabalho é investigar o comportamento dos fatores de risco tamanho, índice book-to-market e momento, no mercado acionário brasileiro, em condições de i) alta e baixa do mercado acionário e ii) expansão e retração monetária. A amostra foi constituída por todas as ações listadas na Bovespa, de junho de 1995 a junho de 2007. A metodologia de testes empregada foi a mesma utilizada por Fama &French (1993) na construção das carteiras e fatores de risco. Os resultados indicaram evidências de uma importante influência exercida pelas condições do mercado acionário e pela política monetária sobre a regularidade do comportamento dos fatores de risco no mercado brasileiro.
O ecletismo do paradigma da sustentabilidade: construção e análise a partir dos estudos organizacionais
Authors: Munck Luciano , Souza Rafael Borim de
Published: April 2011

Este artigo possui dois objetivos principais: (1) investigar as nuanças que um paradigma da sustentabilidade, como proposição de lente de observação da realidade para os contextos organizacionais deve assumir; e (2) apresentar e definir um paradigma da sustentabilidade, eclético, dialógico e flexível, por meio do qual o desenvolvimento sustentável possa ser assumido como um fenômeno de pesquisa coerente junto aos estudos organizacionais. Realizou-se um estudo qualitativo, exploratório e bibliográfico. Foi desenvolvido um referencial teórico com o intuito de observar possíveis inter-relações entre algumas discussões sobre o desenvolvimento sustentável e contribuições específicas extraídas dos estudos organizacionais. O paradigma da sustentabilidade, em suma, é concebido pelo estudo da relação entre o desenvolvimento sustentável e os estudos organizacionais, uma vez que compreende o desenvolvimento sustentável como um fenômeno de investigação que importa ao contexto das organizações.
Dinâmicas de grupo e gerenciamento de impressões: estudo sobre auto-apresentação na seleção de estagiários e trainees
Authors: Hallak Rodrigo Telles Pires , Carvalho José Luis Felicio
Published: April 2011

Estágios profissionais e programas de trainees estão entre as modalidades mais importantes de ingresso no mercado de trabalho. Em processos seletivos para tais vagas, as dinâmicas de grupo são amplamente adotadas por empresas e consultorias de Recursos Humanos. Por constituir uma técnica vivencial, as dinâmicas desvelam a possibilidade de utilização de Gerenciamento de Impressões (GI) por parte dos candidatos. O presente estudo tem por objetivo identificar se estudantes de Administração recorrem a estratégias e táticas de GI ao participar desse tipo de seleção. A pesquisa buscou investigar também se, na visão dos candidatos, seus concorrentes e os próprios selecionadores valem-se do recurso. A parte empírica do estudo, que se seguiu a uma revisão de literatura com foco nos temas pertinentes, comportou uma pesquisa de base qualitativa conduzida a partir de um questionário respondido por estudantes matriculados em duas universidades do Rio de Janeiro. O tratamento dos dados seguiu o protocolo da análise de conteúdo. Como conclusão, sugere-se haver evidências do uso de GI em dinâmicas de grupo, não somente por parte dos candidatos, como também por parte das empresas contratantes. Há indícios de que a dinâmica pode ser percebida como processo injusto, que favorece candidatos mais afeitos a comportamentos teatralizados.
Schumpeter e o desenvolvimento tecnológico: uma visão aplicada às pequenas e médias empresas
Authors: Brasil Marcus Vinicius de Oliveira , Nogueira Cláudio André Gondim , Forte Sérgio Henrique Arruda Cavalcante
Published: April 2011

A teoria schumpeteriana considera que quanto maiores forem as empresas em um determinado mercado, maior será a competição existente, pois as grandes empresas possuem uma maior capacidade inovadora e de resistência em relação às pequenas, já que entre as grandes o ritmo de introdução de inovações seria mais intenso. Entretanto, faz-se necessário considerar com mais ênfase a capacidade inovadora das Pequenas e Médias Empresas (PMEs). Assim, a questão fundamental para estas empresas está vinculada às suas capacidades de aproveitarem as novas oportunidades que o mercado oferece, dos recursos que elas dispõem ou desenvolvem, das potenciais parcerias que poderiam firmar, bem como das suas ligações com instituições de pesquisa. Portanto, o objetivo principal deste ensaio é apresentar a teoria schumpeteriana sobre o desenvolvimento tecnológico, mostrando-a como uma abordagem fundamental para se compreender as estratégias inovadoras das empresas de maior porte, mas cujos princípios básicos também se aplicam às empresas de menor porte. Nas considerações finais apresenta-se que a inovação tecnológica preconizada por Schumpeter, além de ser um instrumento fundamental para o desenvolvimento e crescimento econômico pode impulsionar a concorrência entre as grandes e também as menores empresas, e podem estas também propiciar parcerias levando-as a um relacionamento ganha-ganha.
Firmas integradoras de sistemas, suas capacitações e fontes de tecnologia – O caso da Empresa Brasileira de Aeronáutica (Embraer)
Authors: Chagas Junior Milton de Freitas , Cabral Arnoldo Souza , Campanário Milton de Abreu
Published: April 2011

A dinâmica da inovação dos sistemas complexos tem sido tratada como uma categoria distinta de análise, uma vez que apresenta características muito diferentes daquelas dos sistemas de produção em massa e de processo contínuo. Sistemas complexos são bens de capital de alto valor agregado geralmente produzidos em pequenos lotes, através de alianças temporárias entre diversas organizações, porque uma única firma não consegue desenvolver toda a base de conhecimentos necessários para sua produção. O uso de fontes externas de conhecimento e componentes tem aumentado na estratégia competitiva das firmas – através da modularidade -, para fazer frente à crescente complexidade dos produtos, em termos de número de componentes e especialização de sua base de conhecimento relevante. A literatura sobre o assunto define firma integradora de sistemas como a organização que estabelece e lidera uma rede dos pontos de vista organizacional e tecnológico. Mesclando características positivas dos mercados e das hierarquias, estas redes ajudam a coordenação das atividades econômicas, especialmente aqueles com caráter inovador. Utilizando a visão baseada em recursos da firma como referencial teórico, o objetivo desta pesquisa é analisar, através de um estudo de caso, as capacitações requeridas para integrar conhecimentos, internos e externos, visando à coordenação de projetos e programas que atendam à evolução dos requisitos de seus clientes. O artigo propõe um modelo cognitivo estilizado que permite compreender o desenvolvimento de capacitações em integração de sistemas.
Using surface remote sensors to derive mixed-phase cloud radiative forcing: an example from M-PACE
Authors: de Boer G. , Collins W. D. , Menon S. , Long C. N.
Published: April 2011

Abstract. A suite of ground-based measurements are used in conjunction with a column version of the Rapid Radiative Transfer Model (RRTMG) to derive the cloud radiative forcing of mixed-phase stratiform clouds observed during the United States Department of Energy (US DOE) Atmospheric Radiation Measurement (ARM) Mixed-Phase Arctic Clouds Experiment (M-PACE) between September and November of 2004. In total, sixteen half hour time periods are reviewed due to their coincidence with radiosonde launches. Cloud liquid (ice) water paths are found to range between 11.0–366.4 (0.5–114.1) gm−2, and cloud physical thicknesses fall between 286–2075 m. Combined with temperature and hydrometeor size estimates, this information is used to calculate surface radiative fluxes using RRTMG, which are demonstrated to generally agree with measured fluxes from surface-based radiometric instrumentation. Errors in longwave flux estimates are found to be largest for thin clouds, while shortwave flux errors are generally largest for thicker clouds. Cloud radiative forcing is calculated for all profiles, and illustrates the dominance of the longwave component during this time of year, with net cloud forcing generally between 50 and 90 Wm−2. Finally, sensitivity of calculated surface fluxes to droplet effective radius, surface albedo and surface temperature are tested, with changes in minimum droplet size between 3.5 and 10 μm altering the surface shortwave flux by up to 50 Wm−2, and changes in surface albedo between 0.5 and 0.95 altering surface shortwave fluxes by up to 85 Wm−2.
Middle Jurassic-Early Cretaceous high-latitude sea-surface temperatures from the Southern Ocean
Authors: Jenkyns H. C. , Schouten-Huibers L. , Schouten S. , Sinninghe Damsté J. S.
Published: April 2011

Abstract. Although a division of the Phanerozoic climatic modes of the Earth into "greenhouse" and "icehouse" phases is widely accepted, whether or not polar ice developed during the relatively warm Jurassic and Cretaceous Periods is still under debate. In particular, there is a range of isotopic and biotic evidence that favours the concept of discrete "cold snaps", marked particularly by migration of certain biota towards lower latitudes. Extension of the use of the palaeotemperature proxy TEX86 back to the middle Jurassic indicates that relatively warm sea-surface conditions (26–30 °C) existed from this interval (~160 Ma) to the Early Cretaceous (~115 Ma) in the Southern Ocean. The Jurassic and Cretaceous "cold snaps" represent falls of only a few degrees. Belemnite δ18O data give palaeotemperatures that are consistently lower by ~14 °C than does TEX86 and these molluscs likely record conditions below the thermocline. Such long-term warm climatic conditions would only be compatible with the existence of continental ice if appreciable areas of high altitude existed on Antarctica, and/or in other polar regions, during the Mesozoic Era.
Determining irrigation needs of sorghum from two-source energy balance and radiometric temperatures
Authors: Sánchez J. M. , López-Urrea R. , Rubio E. , Caselles V.
Published: April 2011

Abstract. Estimates of surface actual evapotranspiration (ET) can assist in predicting crop water requirements. An alternative to the traditional crop-coefficient methods are the energy balance models. The objective of this research was to show how surface temperature observations can be used, together with a two-source energy balance model, to determine crop water use throughout the different phenological stages of a crop grown. Radiometric temperatures were collected in a sorghum (Sorghum bicolor) field as part of an experimental campaign carried out in Barrax, Spain, during the 2010 summer growing season. Performance of the Simplified Two-Source Energy Balance (STSEB) model was evaluated by comparison of estimated ET with values measured on a weighing lysimeter. Errors of ±0.14 mm h−1 and ±1.0 mm d−1 were obtained at hourly and daily scales, respectively. Accumulated crop water use during the campaign resulted 500 mm versus the total 524 mm measured by the lysimeter. It is then shown that thermal radiometry can provide precise crop water necessities and is a promising tool for irrigation management.
Ice stream or not? Radio-echo sounding of Carlson Inlet, West Antarctica
Authors: King E. C.
Published: April 2011

Abstract. The Antarctic Ice Sheet loses mass to the surrounding ocean mainly by drainage through a network of ice streams: fast-flowing glaciers bounded on either side by ice flowing one or two orders of magnitude more slowly. Ice streams flow despite low driving stress because of low basal resistance but are known to cease flowing if the basal conditions change, which can take place when subglacial sediment becomes dewatered by freezing or by a change in hydraulic pathways. Carlson Inlet, Antarctica has been interpreted as a stagnated ice stream, based on surface and basal morphology and shallow radar reflection profiling. To resolve the question of whether the flow history of Carlson Inlet has changed in the past, I conducted a ground-based radar survey of Carlson Inlet, the adjacent part of Rutford Ice Stream, and Talutis Inlet, West Antarctica. This survey provides details of the internal ice stratigraphy and allows the flow history to be interpreted. Tight folding of isochrones in Rutford Ice Stream and Talutis Inlet is interpreted to be the result of lateral compression during convergent flow from a wide catchment into a narrow, fast-flowing trunk. In contrast, the central part of Carlson Inlet has gently-folded isochrones that drape over the bed topography, suggestive of local accumulation and slow flow. A 1-D thermo-mechanical model was used to estimate the age of the ice. I conclude that the ice in the centre of Carlson Inlet has been near-stagnant for between 3500 and 6800 years and that fast flow has not occurred there during that time period.
Central Venous Catheters: Legal Issues
Authors: Gallieni Maurizio , Martina Valentina , Rizzo Maria Antonietta , Gravellone Luciana , Mobilia Francesca , Giordano Antonino , Cusi Daniele , Genovese Umberto
Published: April 2011

In dialysis patients, both central venous catheter (CVC) insertion and CVC use during the dialysis procedure pose important legal issues, because of potentially severe, even fatal, complications. The first issue is the decision of the kind of vascular access that should be proposed to patients: an arteriovenous (AV) fistula, a graft, or a CVC. The second issue, when choosing the CVC option, is the choice of CVC: nontunneled versus tunneled. Leaving a temporary nontunneled CVC for a prolonged time increases the risk of complications and could raise a liability issue. Even when choosing a long-term tunneled CVC, nephrologists should systematically explain its potential harms, presenting them as “unsafe for long-term use” unless there is a clear contraindication to an AV native or prosthetic access. Another critical issue is the preparation of a complete, informative, and easy-to-understand consent form. The CVC insertion procedure has many aspects of legal interest, including the choice of CVC, the use of ECG monitoring, the use of ultrasound guidance for cannulation, and the use of fluoroscopy for checking the position of the metal guidewire during the procedure as well as the CVC tip before the end of the procedure. Use of insertion devices and techniques that can prevent complications should obviously be encouraged. Complications of CVC use are mainly thrombosis and infection. These are theoretically expected as pure complications (and not as malpractice effects), but legal issues might relate to inappropriate catheter care (in both the inpatient and outpatient settings) rather than to the event per se. Thus, in the individual case it is indeed very difficult to establish malpractice and liability with a catheter-related infection or thrombosis. In conclusion, we cannot avoid complications completely when using CVCs, but reducing them to a minimum and adopting safe approaches to their insertion and use will reduce legal liability.
Genomics and Pain Research in Sickle Cell Disease: An Explanation of Heterogeneity?
Authors: Adegbola Maxine
Published: April 2011

Sickle cell disease (SCD) is a chronic illness, and the major complication, pain, results in complex multidimensional problems that affect an individual's ability to maintain adequate quality of life in multiple areas. Chronic SCD pain is inadequately treated, because it is not well understood, and the degree of chronic pain, clinical presentation, and sequela complications can vary from patient to patient, even among individuals with the same SCD genotype. The reason for this variation is unknown, but the underlying cause might be genetic. Researchers have not explored the contribution of a genomic variable to the occurrence of heterogeneous chronic SCD pain. Previous research on the guanosine triphosphate cyclohydrolase (GCH1) gene suggests that in some cases, phenotypic heterogeneity in human sensitivity to pain correlates with underlying genotypic variations in the GCH1 gene. These findings imply that genotypic variations might also explain why some SCD patients experience more chronic pain than others.
Organic Proton‐Conducting Molecules as Solid‐State Separator Materials for Fuel Cell Applications
Authors: Jiménez‐García Lucía , Kaltbeitzel Anke , Enkelmann Volker , Gutmann Jochen S. , Klapper Markus , Müllen Klaus
Published: April 2011

Organic proton‐conducting molecules are presented as alternative materials to state‐of‐the‐art polymers used as electrolytes in proton‐exchanging membrane (PEM) fuel cells. Instead of influencing proton conductivity via the mobility offered by polymeric materials, the goal is to create organic molecules that control the proton‐transport mechanism through supramolecular order. Therefore, a series of phosphonic acid‐containing molecules possessing a carbon‐rich hydrophobic core and a hydrophilic periphery was synthesized and characterized. Proton conductivity measurements as well as water uptake and crystallinity studies (powder and single‐crystal X‐ray analysis) were performed under various conditions. These experiments reveal that proton mobility is closely connected to crystallinity and strongly dependent on the supramolecular ordering of the compound. This study provides insights into the proton‐conducting properties of this novel class of materials and the mechanisms responsible for proton transport.
Polymer‐Stabilized Chromonic Liquid‐Crystalline Polarizer
Authors: Park Seul‐Ki , Kim So‐Eun , Kim Dae‐Yoon , Kang Shin‐Woong , Shin Seunghan , Kuo Shiao‐Wei , Hwang Seok‐Ho , Lee Seung Hee , Lee Myong‐Hoon , Jeong Kwang‐Un
Published: April 2011

Robust coatable polarizer is fabricated by the self‐assembly of lyotropic chromonic liquid crystals and subsequent photo‐polymerizing processes. Their molecular packing structures and optical behaviors are investigated by the combined techniques of microscopy, scattering and spectroscopy. To stabilize the oriented Sunset Yellow FCF (H‐SY) films and to minimize the possible defects generated during and after the coating, acrylic acid (AA) is added to the H‐SY/H2O solution and photo‐polymerized. Utilizing cross‐polarized optical microscopy, phase behaviors of the H‐SY/H2O/AA solution are monitored by varying the compositions and temperatures of the solution. Based on the experimental results of two‐dimensional wide angle X‐ray diffraction and selected area electron diffraction, the H‐SY crystalline unit cell is determined to be a monoclinic structure with the dimensions of a = 1.70 nm, b = 1.78 nm, c = 0.68 nm, α = β = 90.0° and γ = 84.5°. The molecular arrangements in the oriented H‐SY films were further confirmed by polarized Fourier‐transform infrared spectroscopy. The polymer‐stabilized H‐SY films show good mechanical and chemical stabilities with a high polarizability. Additionally, patterned polarizers are fabricated by applying a photo‐mask during the photo‐polymerization of AA, which may open new doors for practical applications in electro‐optic devices.
Influence of Hole‐Transport Layers and Donor Materials on Open‐Circuit Voltage and Shape of I–V Curves of Organic Solar Cells
Authors: Tress Wolfgang , Leo Karl , Riede Moritz
Published: April 2011

The effect of injection and extraction barriers on flat heterojunction (FHJ) and bulk heterojunction (BHJ) organic solar cells is analyzed. The barriers are realized by a combination of p‐type materials with HOMOs varying between –5.0 and –5.6 eV as hole‐transport layer (HTL) and as donor in vacuum‐evaporated multilayer p‐i‐metal small‐molecule solar cells. The HTL/donor interface can be seen as a model for the influence of contacts in organic solar cells in general. Using drift‐diffusion simulations we are well able to reproduce and explain the experimental I–V curves qualitatively. In FHJ solar cells the open‐circuit voltage (Voc) is determined by the donor and is independent of the HTL. In BHJ solar cells, however, Voc decreases if injection barriers are present. This different behavior is caused by a blocking of the charge carriers at a spatially localized donor/acceptor heterojunction, which is only present in the FHJ solar cells. The forward current is dominated by the choice of HTL. An energy mismatch in the HOMOs leads to kinks in the I–V curves in the cases for which Voc is independent of the HTL.
Electrospinning Preparation and Drug‐Delivery Properties of an Up‐conversion Luminescent Porous NaYF4:Yb3+, Er3+@Silica Fiber Nanocomposite
Authors: Hou Zhiyao , Li Chunxia , Ma Pingan , Li Guogang , Cheng Ziyong , Peng Chong , Yang Dongmei , Yang Piaoping , Lin Jun
Published: April 2011

Up‐conversion (UC) luminescent porous silica fibers decorated with NaYF4:Yb3+, Er3+ nanocrystals (NCs) (denoted as NaYF4:Yb3+, Er3+@silica fiber) are prepared by the electrospinning process using cationic surfactant P123 as a template. Monodisperse and hydrophobic oleic acid capped β‐NaYF4: Yb3+, Er3+ NCs are prepared by thermal decomposition methodology. Then, these NCs are transferred into aqueous solution by employing cetyltrimethylammonium bromide (CTAB) as secondary surfactant. The water‐dispersible β‐NaYF4:Yb3+, Er3+ NCs are dispersed into precursor electrospinning solution containing P123 and tetraethyl orthosilicate (TEOS), followed by preparation of precursor fibers via electrospinning. Finally, porous α‐NaYF4:Yb3+, Er3+@silica fiber nanocomposites are obtained after annealing the precursor fibers containing β‐NaYF4:Yb3+, Er3+ at 550 °C. The as‐prepared α‐NaYF4:Yb3+, Er3+@silica fiber possesses porous structure and UC luminescence properties simultaneously. Furthermore, the obtained nanocomposites can be used as a drug delivery host carrier and drug storage/release properties are investigated, using ibuprofen (IBU) as a model drug. The results indicate that the IBU–loaded α‐NaYF4:Yb3+, Er3+@silica fiber nanocomposites show UC emission of Er3+ under 980 nm NIR laser excitation and a controlled release property for IBU. Meanwhile, the UC emission intensity of IBU–α‐NaYF4:Yb3+, Er3+@silica fiber system varies with the released amount of IBU.
Melt index prediction based on fuzzy neural networks and PSO algorithm with online correction strategy
Authors: Liu Xinggao , Zhao Chengye
Published: April 2011

A black‐box modeling scheme to predict melt index (MI) in the industrial propylene polymerization process is presented. MI is one of the most important quality variables determining product specification, and is influenced by a large number of process variables. Considering it is costly and time consuming to measure MI in laboratory, a much cheaper and faster statistical modeling method is presented here to predicting MI online, which involves technologies of fuzzy neural network, particle swarm optimization (PSO) algorithm, and online correction strategy (OCS). The learning efficiency and prediction precision of the proposed model are checked based on real plant history data, and the comparison between different learning algorithms is carried out in detail to reveal the advantage of the proposed best‐neighbor PSO (BNPSO) algorithm with OCS. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Ethmoid skull‐base height: a clinically relevant method of evaluation
Authors: Ramakrishnan Vijay R. , Suh Jeffrey D. , Kennedy David W.
Published: April 2011

Background:

The Keros classification scheme has been used to describe the ethmoid skull‐base configuration; however, this scheme only partially addresses key anatomic issues in ethmoid skull‐base injury avoidance during surgery.

Methods:

Coronal computed tomography (CT) scans were reviewed for 200 patients undergoing sinus evaluation at a tertiary care institution. Keros classification, maxillary sinus:ethmoid height ratio, and the skull‐base height:orbital height ratio were recorded for each patient. The Pearson correlation coefficient was used to determine if a relationship existed between the 3 sets of measurements.

Results:

In the Keros classification scheme, 42% of patients were in class I, 50% class II, and 8% class III. In maxillary sinus to ethmoid height ratio, 58% were 1:1, 37% were 2:1, and 5% were >2:1. In the skull‐base height to total orbital height ratio, 65% were in class I, 18% class II, and 17% in class III. There was no correlation between the classification schemes.

Conclusion:

The importance of the Keros classification lies primarily in the avoidance of iatrogenic injury to the cribriform region and medial ethmoid roof. To avoid penetration of the ethmoidal roof, the ethmoid skull‐base height must be separately examined in relation to the orbit and total vertical dimension of the sinuses.
Synthesis of ferrocene‐containing N‐aryloxo β‐ketoiminate lanthanide complexes and polymerization of ε‐caprolactone
Authors: Huang Ling‐Ling , Han Xiang‐Zong , Yao Ying‐Ming , Zhang Yong , Shen Qi
Published: April 2011

The synthesis, characterization and ε‐caprolactone polymerization behavior of lanthanide amido complexes stabilized by ferrocene‐containing N‐aryloxo functionalized β‐ketoiminate ligand FcCOCH2C(Me)N(2‐HO‐5‐But‐C6H3) (LH2, Fc = ferrocenyl) are described. The lanthanide amido complexes [LLnN(SiMe3)2(THF)]2 [Ln = Nd (1), Sm (2), Yb (3), Y (4)] were synthesized in good yields by the amine elimination reactions of LH2 with Ln[N(SiMe3)2]3(µ‐Cl)Li(THF)3 in a 1:1 molar ratio in THF. These complexes were characterized by IR spectroscopy and elemental analysis, and 1H NMR spectroscopy was added for the analysis of complex 4. The definitive molecular structures of complexes 1 and 3 were determined by X‐ray diffraction studies. Complexes 1–4 can initiate the ring‐opening polymerization of ε‐caprolactone with moderate activity. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of double promoters on direct synthesis of triethoxysilane in gas–solid stirred fluidized bed
Authors: Lei Zhang , Sue Hao , Chunhui Yang , Ji Li , Kai Yang , Chenfa Hu , Shibin Ge
Published: April 2011

The reaction of silicon with ethanol was carried out in a gas–solid stirred fluidized bed, with cuprous chloride prepared by a wet process as the catalyst. The effect of hydrogen fluoride and ethyl chloride addition on formation of triethoxysilane in the direct process was described and discussed. The catalytic activity was evaluated using online gas chromatography, X‐ray diffraction and scanning electron microscopy to study the contact mass. The results show that the promoters hydrogen fluoride and ethyl chloride not only supplemented anions, but also depressed the catalytic activity of metallic copper. The comparison of technical‐grade silicon and polycrystalline silicon showed many differences in reactivity, reaction rate and induction period. Furthermore, the yield, selectivity of triethoxysilane and reaction rate were improved significantly with additions of hydrogen fluoride and ethyl chloride. Copyright © 2011 John Wiley & Sons, Ltd.
Modeling and analysis of the compatibility of poly(ethylene oxide)/poly(methyl methacrylate) blends with surface and shear inducing effects
Authors: Mu Dan , Li Jian‐Quan , Wang Song
Published: April 2011

The compatibility of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) blends was studied over a wide range of compositions at 400 K by mesoscopic modeling. Sixteen patterned surfaces of four types were designed and designated as “ci,” “co,” “gra,” and “rg” to study their influence on changing the microscopic phase morphology. The topography of the “ci” series surfaces was shaped by semicircular balls. Different radii were applied to simulate different degrees of surface roughness. The “co” series were composed of cubic columns as the mask, and the cubic columns were separated by equal spaces. Various sizes and heights of columns were used to simulate different degrees of surface roughness. The “gra” series were composed of surfaces with different areas of section and the same height to simulate different degrees of surface roughness. The “rg” series were composed of concentric cuboids with continuous increasing heights and sizes. The “co” series surfaces were the most efficient distribution in changing the microscopic phase morphology, the “gra” and “rg” series surfaces were both the secondary, and the “ci” series surfaces placed the last. The results show that the effect of inducing surfaces depended on both the pattern of surfaces and the compositions of the blends. The shear effect was effective in changing the phase morphology, but its influencing effect depended on not only the shear rate, but also the compositions of the blends, especially when the blends were rich in PEO. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of electron beam irradiation on polyacrylonitrile precursor fibers and stabilization process
Authors: Yuan Huiwu , Wang Yuansheng , Liu Pengbo , Yu Hongwei , Ge Bao , Mei Yongjia
Published: April 2011

The electron beam was imposed on the polyacrylonitrile precursor fibers before the fibers were stabilized. The effect of electron beam irradiation on the chemical structure, transverse section, and surface morphology and thermal properties of the fibers in the process of stabilization was characterized by the use of Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and differential scanning calorimeter, respectively. A parameter η = I(CN)/[I(CN) + I(CN)] was defined to evaluate the extent of cyclization in the stabilization process. The kinetic parameters, viz. activation energy (E) and pre‐exponential factor (A) of the stabilization reactions, were calculated by Kissinger method. FTIR analysis indicated that the cyclization of nitrile groups was initiated at room temperature by electron beam irradiation. The transformation of CN groups to CN ones was accelerated in the process of stabilization. The extent of cyclization of the stabilized fibers was increased. SEM analysis indicated that irradiation could also decrease the internal and surface defects of the stabilized fibers treated at 300°C. The activation energy of cyclization reaction was reduced from 302 to 280 kJ/mol and 260 kJ/mol through 100 and 200 kGy electron beam irradiation, respectively. The reaction temperature range was expanded, and the exothermic rate was slowed down in the process of stabilization, which was the reason why the stabilized fibers have improved cyclization degree and less internal defects. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of chain extension on the properties of PLA/TPS blends
Authors: Li Hongbo , Huneault Michel A.
Published: April 2011

Multifunctional Epoxy‐based copolymers can be used as chain‐extender (CE) to increase the molecular weight and create branching in polylactides (PLA). In this study, the effect of a multifunctional epoxy‐acrylic‐styrene copolymer on the properties of PLA/Thermoplastic Starch (PLA/TPS) blends was investigated. The PLA/TPS blends were prepared by twin‐screw extrusion. The dry‐starch and plasticizers were mixed together in the first half of the extruder to complete starch gelatinization. Water was removed by devolatilization at midex‐truder and the PLA matrix was mixed with the water‐free TPS in the latter portion of the compounding process. The standard blends comprised 27% TPS in the PLA matrix. The TPS phase itself comprised 36% plasticizer in the form of glycerol or sorbitol. A maleic anhydride grafted PLA (PLAg) was also used in selected blends to examine the effect of interfacial modification on the morphology of chain‐extended blends. The blends were injection molded into standard test bars and their tensile properties were measured. Differential scanning calorimetry was carried out to examine the effect of chain extension on PLA's ability to crystallize. Oscillatory‐shear rheology was used to monitor changes in blend viscosity. Finally, scanning electron microscopy on microtomed and acid‐etched samples was carried out to assess the blend morphology. It was found that the combination of interfacial modification and chain‐extension strategies led to greatly improved ductility. The viscosity of the PLA/TPS blends was also dramatically increased by adding a small amount of epoxy‐based chain extender. This is of great interest for polymer processing techniques (such as foaming or film blowing) that require high melt strength. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Estrogen receptor–related receptor α regulation by interleukin‐1β in prostaglandin E2– and cAMP‐dependent pathways in osteoarthritic chondrocytes
Authors: Bonnelye Edith , Reboul Pascal , Duval Nicolas , Cardelli Marco , Aubin Jane E.
Published: April 2011

Objective

We reported previously that the orphan nuclear receptor, estrogen receptor–related receptor α (ERRα), is expressed in articular chondrocytes and is dysregulated in a mouse model of inflammatory arthritis. The aim of this study, therefore, was to determine whether ERRα is also dysregulated in patients with osteoarthritis (OA).

Methods

ERRα messenger RNA (mRNA) and protein were quantified in normal and OA cartilage samples and in OA chondrocytes in vitro, with and without short‐term treatment with a variety of OA‐associated factors and signaling pathway agonists and inhibitors.

Results

ERRα expression was lower in OA than in normal articular cartilage. Interleukin‐1β (IL‐1β) markedly up‐regulated ERRα expression in OA chondrocytes in vitro, and agonist or inhibitor treatment indicated that the up‐regulation was dependent on cyclooxygenase 2 (COX‐2; NS398), prostaglandin E2, cAMP (8‐bromo‐cAMP), and protein kinase A (PKA; KT5720). Treatment with the ERRα inverse agonist XCT790 decreased the expression of SOX9 and the up‐regulation of ERRα by IL‐1β, suggesting autoregulation of ERRα in the IL‐1β pathway. Matrix metalloproteinase 13 (MMP‐13) expression was also decreased by treatment with XCT790 plus IL‐1β versus IL‐1β alone, and the down‐regulation of MMP‐13 mRNA and protein observed with XCT790 alone suggests that the up‐regulation of MMP‐13 by IL‐1β is ERRα‐dependent.

Conclusion

We report the first evidence that ERRα expression is regulated by IL‐1β in COX‐2–, cAMP‐, and PKA‐dependent pathways in OA chondrocytes. We confirmed that SOX9 is an ERRα target gene in human, as in rodent, chondrocytes and identified MMP‐13 as a potential new target gene, which suggests that ERRα may both respond to the healing signal and contribute to extracellular degradation in OA cartilage.
A Series of Carboxylic‐Functionalized Ionic Liquids and their Solubility for Lanthanide Oxides
Authors: Li Huanrong , Li Dan , Wang Yige , Ru Qiaorong
Published: April 2011

Herein we report the synthesis of propanoic acid functionalized ionic liquids (ILs) with various lengths of alkyl chain on the imidazole ring. The synthesized propanoic acid functionalized ILs were used to dissolve Eu2O3 (or Tb4O7) due to the formation of europium(III) (or terbium(III)) carboxylate, aimed to get soft luminescent materials combining the properties of ILs and attractive luminescent properties of lanthanide ions. The luminescent behavior of Eu3+ and Tb3+ in the ILs were investigated by luminescence spectroscopy. The affect of the alkyl chain on the luminescent behavior (the asymmetry parameter (R), the lifetime of 5D0, and the 5D0 quantum efficiency) of Eu3+ has been discussed.
Fluorescent Sensing and Discrimination of ATP and ADP Based on a Unique Sandwich Assembly of Pyrene‐Adenine‐Pyrene
Authors: Xu Zhaochao , Spring David R. , Yoon Juyoung
Published: April 2011

It is still a challenging task to discriminate adenosine‐5′‐triphosphate (ATP) from various nucleoside triphosphates, such as GTP, CTP, UTP, and TTP. The ability to distinguish ATP from adenosine diphosphate (ADP) by fluorescent signals is also urgently desired. Herein, we report two pyrene‐based zinc complexes as nucleoside polyphosphate receptors with high selectivity for ATP and ADP based on fluorescence and NMR studies. A unique pyrene–adenine–pyrene sandwich assembly was observed in the case of compound 1 with ATP or ADP, resulting in the increase of monomer fluorescence intensity; whereas the other bases of nucleoside triphosphates, such as GTP, CTP, UTP, and TTP were not sandwiched, resulting in a switch in the monomer–excimer fluorescence of pyrene. The different binding patterns of various nucleobases with a pyrene–pyrene assembly make 1 a highly selective fluorescent sensor for ANP (N=di, tri). In the case of compound 2, the first 0.5 equivalents of ATP induced a strong excimer emission, whilst ADP induced a large enhancement in the monomeric fluorescent peak. This fluorescence change makes 2 an efficient sensor to discriminate ATP from ADP.
Autism spectrum disorders are associated with an elevated autoantibody response to tissue transglutaminase‐2
Authors: Rosenspire Allen , Yoo Wonsuk , Menard Sherri , Torres Anthony R.
Published: April 2011

We report that a significant number of autistic children have serum levels of IgA antibodies above normal to the enzyme tissue transglutaminase II (TG2), and that expression of these antibodies to TG2 is linked to the (HLA)‐DR3, DQ2 and DR7, DQ2 haplotypes. TG2 is expressed in the brain, where it has been shown to be important in cell adhesion and synaptic stabilization. Thus, these children appear to constitute a subpopulation of autistic children who fall within the autism disease spectrum, and for whom autoimmunity may represent a significant etiological component of their autism. Autism Res 2011,4:242–249. © 2011 International Society for Autism Research, Wiley Periodicals, Inc.
Role of mammography in the triple assessment of single-quadrant breast symptoms
Authors: Donnelly J , Iqbal M , Devaraj S , Marriott P J , Corder A P
Published: April 2011

Background

Most women over the age of 35 years referred to a breast clinic have single-quadrant symptoms and undergo mammography (MMG) as part of the triple assessment of these. A proportion of these women has no abnormality clinically or on ultrasonography (P1 U1). The aim of this study was to assess the additional contribution of MMG in diagnosing cancer in patients with P1 U1 findings and to consider whether it is safe to be more selective when requesting MMG.

Methods

Over a 2-year interval the clinical and radiological details of women whose single-quadrant breast symptoms were assessed as P1 U1, and who were then sent for MMG, were entered into a database. The results of further investigations initiated by a non-benign MMG report were recorded, and the patients reviewed to establish how many cancers were diagnosed purely by MMG and whether these were located at the site of symptoms.

Results

There were 454 women in the study group, representing 17·5 per cent of all new referrals. Twenty-one patients (4·6 per cent) were recalled following a non-benign MMG result, ten of whom required image-guided biopsy. Cancer was diagnosed in three patients (0·7 per cent of the study group), located in the contralateral breast in two women and a different ipsilateral quadrant in one.

Conclusion

MMG in this subset of patients did not increase the cancer detection rate at the site of symptoms and therefore constituted screening. The rationale for requesting MMG in these patients, and indeed for applying the triple assessment rule, should be reconsidered.
Clinical and cellular effects of hypothermia, acidosis and coagulopathy in major injury
Authors: Thorsen K , Ringdal K G , Strand K , Søreide E , Hagemo J , Søreide K
Published: April 2011

Background

Hypothermia, acidosis and coagulopathy have long been considered critical combinations after severe injury. The aim of this review was to give a clinical update on this triad in severely injured patients.

Methods

A non-systematic literature search on hypothermia, acidosis and coagulopathy after major injury was undertaken, with a focus on clinical data from the past 5 years.

Results

Hypothermia (less than 35 °C) is reported in 1·6–13·3 per cent of injured patients. The occurrence of acidosis is difficult to estimate, but usually follows other physiological disturbances. Trauma-induced coagulopathy (TIC) has both endogenous and exogenous components. Endogenous acute traumatic coagulopathy is associated with shock and hypoperfusion. Exogenous effects of dilution from fluid resuscitation and consumption through bleeding and loss of coagulation factors further add to TIC. TIC is present in 10–34 per cent of injured patients, depending on injury severity, acidosis, hypothermia and hypoperfusion. More expedient detection of coagulopathy is needed. Thromboelastography may be a useful point-of-care measurement. Management of TIC is controversial, with conflicting reports on blood component therapy in terms of both outcome and ratios of blood products to other fluids, particularly in the context of civilian trauma.

Conclusion

The triad of hypothermia, acidosis and coagulopathy after severe trauma appears to be fairly rare but does carry a poor prognosis. Future research should define modes of early detection and targeted therapy.