bluuebunny/crossref_metadata_2025 huggingface dataset:
Agenesis of the ductus venosus—A case with favorable outcome after early signs of cardiac failure
Authors: Hofmann Sigrun R. , Heilmann Antje , Häusler Hans J. , Kamin Gabriele , Nitzsche Katharina I.
Published: April 2012

Absence of the ductus venosus (ADV) is a rare vascular anomaly. Its prognosis depends on the pathway of the umbilical flow to the systemic venous circulation, and the presence or absence of associated structural or chromosomal anomalies, sometimes resulting in hydrops fetalis. In cases with isolated ADV in the absence of associated anomalies, survival rates are as high as 85%, depending on the shunt situation. Here, we report a patient with ADV and extrahepatic umbilical vein drainage with favorable outcome after intrauterine reversal of early signs of cardiac failure. Diagnosis was made after the appearance of moderate cardiomegaly in the 25th gestational week. Thus, in the case of cardiomegaly with or without further signs of cardiac failure, ultrasound imaging of the venous duct should be considered. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2013
Detailed ultrasound screening in the second trimester: Pictorial essay of normal fetal anatomy
Authors: Tan Sinan , Ipek Ali
Published: April 2012

Today, ultrasound is the main diagnostic tool in the prenatal detection of congenital abnormalities. Therefore, ultrasound examination should be offered to all pregnant women. A detailed sonographic examination of the fetus is usually performed between 18 and 22 weeks of pregnancy. The accurate recognition of normal fetal anatomy is very important for the detection of both minor and major defects. The purpose of this pictorial essay is to show fetal anatomic structures, which have to be examined between the 18th and 22nd weeks of pregnancy, and present their standard measurements systematically and thoroughly in accordance with sonographically obtained ideal sections. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2012
The effects of aging on quantitative sonographic features of rotator cuff tendons
Authors: Yu Tung‐Yang , Tsai Wen‐Chung , Cheng Ju‐Wen , Yang Yun‐Ming , Liang Fang‐Chen , Chen Chien‐Hung
Published: April 2012

Purpose.

Grayscale analysis is a practical, objective, and easy way to quantify echogenicity during ultrasonography. The purpose of the current study was to measure the changes in thickness and echogenicity that result from aging of the rotator cuff and long head of the biceps tendons.

Methods.

The study comprised 45 volunteers, aged between 20 and 84 years and without history of shoulder pain. Participants were divided into three groups: young, middle‐aged, and old. All subjects underwent standard ultrasonography of both shoulders. Tendon thickness and tear were recorded, and images in both transverse and longitudinal scans were taken for grayscale analysis. To reduce the attenuation effect from skin and subcutaneous fat, we used the ratio of echogenicity of the tendon to that of the reference muscle and compared the tendon echogenicity among the different age groups. Sonographic findings were also correlated with age.

Results.

The supraspinatus tendon was significantly thicker in elderly participants and this was positively correlated with age. Moreover, the echogenicity ratio of the supraspinatus tendon decreased in the elderly group and showed a negative correlation with age. There was a higher prevalence of supraspinatus tendon tears in the older participants.

Conclusions.

Our results indicate that supraspinatus tendons became thickened, hypoechogenic, and more likely to tear with age. The study presents a simple and useful method to investigate the echogenicity of the rotator cuff quantitatively. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound 40:471–478, 2012
Sonographic features of histopathologically benign solid breast lesions that have been classified as BI‐RADS 4 on sonography
Authors: Taskin Fusun , Koseoglu Kutsi , Ozbas Serdar , Erkus Muhan , Karaman Can
Published: April 2012

Purpose.

To describe the sonographic (US) features associated with ultrasonography BI‐RADS category 4 lesions that have a benign histopathological outcome.

Methods.

One hundred seventy‐two histopathologically proven benign lesions in 169 patients, which had been classified as BI‐RADS category 4 with ultrasonography, were retrospectively evaluated. Ultrasonography and histopathology findings were analyzed. The frequency of sonographic findings according to the histopathological diagnosis was determined.

Results.

Among the 172 lesions, there were 66 (38%) fibroadenomas, 31 (18%) sclerosing adenoses, 24 (14%) fibrocystic changes, 16 (9%) mastitis/inflammations, 9 (5.5%) intraductal papillomas, 8 (5%) focal fibroses, 4 (2.5%) atypical ductal hyperplasias, 4 (2.5%) fat necroses, 2 (1%) phyllodes tumors, 1 (0.5%) tubular adenomas, 1 (0.5%) epidermal inclusion cysts, and 6 (3.5%) “other benign lesions.” The most frequent sonographic findings were heterogeneity, indistinct margin, microlobulation in fibroadenomas; heterogeneity, irregular‐indefinite margin, and antiparallel orientation in sclerosing adenosis; heterogeneity, microlobulation, and acoustic shadowing in fibrocystic changes.

Conclusions.

BI‐RADS category 4 lesions demonstrate more than one suspicious ultrasonography feature, and biopsy is necessary to diagnose malignancy captured in 33% of lesions in this study. At this time, any lesion with more than one suspicious BI‐RADS US feature cannot avoid a diagnostic biopsy. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2012
Systemically alendronate was incorporated into dental tissues but did not cause morphological or mechanical changes in rats teeth
Authors: Nelson‐Filho Paulo , Lucisano Marília Pacífico , Da Silva Raquel Assed Bezerra , Da Silva Roberto Santana , Serra Mônica Campos , Gerlach Raquel Fernanda , Neto Francisco Carlos Rehder , Carneiro Zumira Aparecida , Zamarioli Ariane , Morse Leslie , Battaglino Ricardo
Published: April 2012

This study evaluated the effect of the systemic use of sodium alendronate in rats in vivo. Forty‐five Wistar rats aged 36 to 42 days and weighing 200 to 230 g were randomly assigned to a control group (n = 20), which received distilled water, and an experimental group (n = 25), which received 2 weekly doses of 1 mg/kg of chemically pure sodium alendronate. The animals were killed after 60 days of treatment. The tibias were removed for analysis of bone mineral density by dual‐energy X‐ray absorptiometry (DXA). Then, the maxillary incisors were extracted for analysis of the mineralized dental tissues using fluorescence spectroscopy (FS), scanning electron microscopy (SEM), bright field microscopy (BFM), and cross‐sectional microhardness (CSMH) testing. DXA and CSMH data were subjected to statistical analysis by Kruskal‐Wallis test (5% significance level). The experimental group presented higher bone mineral density than the control group by DXA. FS analysis revealed presence of alendronate in the mineralized dental tissues of the specimens of the experimental group. Significant morphological differences were not found by SEM and BFM. Enamel and dentin (100 and 300 μm from the dentinoenamel junction) CSMH data did not show significant difference between the control and experimental groups. Based on the obtained results, we conclude that while alendronate increased the bone mineral density and was incorporated into the mineralized dental tissues it did not cause significant alterations in the morphology and microhardness of rat incisor enamel and dentin. Microsc. Res. Tech. 75:1265–1271, 2012. © 2012 Wiley Periodicals, Inc.
Characterization of Epstein–Barr virus (EBV) BZLF1 gene promoter variants and comparison of cellular gene expression profiles in Japanese patients with infectious mononucleosis, chronic active EBV infection, and EBV‐associated hemophagocytic lymphohistiocytosis
Authors: Imajoh Masayuki , Hashida Yumiko , Murakami Masanao , Maeda Akihiko , Sato Tetsuya , Fujieda Mikiya , Wakiguchi Hiroshi , Daibata Masanori
Published: April 2012

Epstein–Barr virus (EBV) genotypes can be distinguished based on gene sequence differences in EBV nuclear antigens 2, 3A, 3B, and 3C, and the BZLF1 promoter zone (Zp). EBV subtypes and BZLF1 Zp variants were examined in Japanese patients with infectious mononucleosis, chronic active EBV infection, and EBV‐associated hemophagocytic lymphohistiocytosis. The results of EBV typing showed that samples of infectious mononucleosis, chronic active EBV infection, and EBV‐associated hemophagocytic lymphohistiocytosis all belonged to EBV type 1. However, sequencing analysis of BZLF1 Zp found three polymorphic Zp variants in the same samples. The Zp‐P prototype and the Zp‐V3 variant were both detected in infectious mononucleosis and chronic active EBV infection. Furthermore, a novel variant previously identified in Chinese children with infectious mononucleosis, Zp‐V1, was also found in 3 of 18 samples of infectious mononucleosis, where it coexisted with the Zp‐P prototype. This is the first evidence that the EBV variant distribution in Japanese patients resembles that found in other Asian patients. The expression levels of 29 chronic active EBV infection‐associated cellular genes were also compared in the three EBV‐related disorders, using quantitative real‐time reverse transcription polymerase chain reaction analysis. Two upregulated genes, RIPK2 and CDH9, were identified as common specific markers for chronic active EBV infection in both in vitro and in vivo studies. RIPK2 activates apoptosis and autophagy, and could be responsible for the pathogenesis of chronic active EBV infection. J. Med. Virol. 84:940–946, 2012. © 2012 Wiley Periodicals, Inc.
Creative Thinking: Processes, Strategies, and Knowledge
Authors: Mumford Michael D. , Medeiros Kelsey E. , Partlow Paul J.
Published: April 2012

Creative achievements are the basis for progress in our world. Although creative achievement is influenced by many variables, the basis for creativity is held to lie in the generation of high‐quality, original, and elegant solutions to complex, novel, ill‐defined problems. In the present effort, we examine the cognitive capacities that make creative problem‐solving possible. We argue that creative problem‐solving depends on the effective execution of a set of complex cognitive processes. Effective execution of these processes is, in turn, held to depend on the strategies employed in process execution and the knowledge being used in problem‐solving. The implications of these observations for improving creative thinking are discussed.
Skeletal muscle and bone marrow derived stromal cells: A comparison of tenocyte differentiation capabilities
Authors: Sassoon Adam A. , Ozasa Yasuhiro , Chikenji Takako , Sun Yu‐Long , Larson Dirk R. , Maas Mary L. , Zhao Chunfeng , Jen Jin , Amadio Peter C.
Published: April 2012

This study investigated the comparative ability of bone marrow and skeletal muscle derived stromal cells (BMSCs and SMSCs) to express a tenocyte phenotype, and whether this expression could be augmented by growth and differentiation factor‐5 (GDF‐5). Tissue harvest was performed on the hind limbs of seven dogs. Stromal cells were isolated via serial expansion in culture. After four passages, tenogenesis was induced using either ascorbic acid alone or in conjunction with GDF‐5. CD44, tenomodulin, collagen I, and collagen III expression levels were compared for each culture condition at 7 and 14 days following induction. Immunohistochemistry (IHC) was performed to evaluate cell morphology and production of tenomodulin and collagen I. SMSCs and BMSCs were successfully isolated in culture. Following tenocytic induction, SMSCs demonstrated an increased mean relative expression of tenomodulin, collagen I, and collagen III at 14 days. BMSCs only showed increased mean relative expression of collagen I, and collagen III at 14 days. IHC revealed positive staining for tenomodulin and collagen I at 14 days for both cell types. The morphology of skeletal muscle derived stromal cells at 14 days had an organized appearance in contrast to the haphazard arrangement of the bone marrow derived cells. GDF‐5 did not affect gene expression, cell staining, or cell morphology significantly. Stromal cells from either bone marrow or skeletal muscle can be induced to increase expression of matrix genes; however, based on expression of tenomodulin and cell culture morphology SMSCs may be a more ideal candidate for tenocytic differentiation. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1710–1718, 2012
On the sensitivity of rotational O2 CARS thermometry to the Herman–Wallis factor
Authors: Bohlin Alexis , Nordström Emil , Bengtsson Per‐Erik , Marrocco Michele
Published: April 2012

Contributions of vibration–rotation interaction to line intensities of pure rotational coherent anti‐Stokes Raman scattering (CARS) of oxygen are here considered in the perspective of what was remarked by us recently for nitrogen. The interaction is conventionally evaluated by means of the so‐called Herman–Wallis (HW) factor, the need of which is conceptually clear but the theoretical expression is debatable, as shown in the literature of this field. In this work, the various solutions for the anisotropic HW factor of pure rotational Raman transitions are compared in light of the implications for the corresponding CARS spectral line intensities. The results show that neglecting the use of HW factors in rotational N2 and O2 CARS thermometry leads to systematic overestimation of temperatures; on the order of 1.5% in the temperature range 300–2100 K in comparison with the use of the most plausible HW factors. The results also suggest that, in general, oxygen is more sensitive than nitrogen to the HW correction, and in particular, different S‐branch HW expressions for oxygen are responsible for thermometric uncertainties between 0.5% and 1% at flame temperatures. Copyright © 2012 John Wiley & Sons, Ltd.
HEAVY METALS IN CONTAMINATED SOILS OF THE RIO SITZERRI FLOODPLAIN (SARDINIA, ITALY): CHARACTERIZATION AND IMPACT ON PEDODIVERSITY
Authors: Vacca A. , Bianco M. R. , Murolo M. , Violante P.
Published: April 2012

Four representative soils located in areas of the Rio Sitzerri floodplain (Sardinia, Italy), which were flooded and covered by materials coming from the metalliferous mine of Montevecchio, were studied to define the total content and the geochemical forms of heavy metals and to discuss their impact on pedodiversity. The significance of heavy metal concentrations in the contaminated soils was assessed by the comparison with data coming from three selected reference soils representative for non‐contaminated areas. Most soils are deep or very deep and consist of a sequence resulting from different sedimentary cycles. The soils located in areas that were flooded and covered by materials coming from the Mine are characterised by the presence of buried horizons and are mainly contaminated by Zn, Ni, Pb, and Cd and, to some extent, by Cr and Cu. The sequential extractions indicated the presence of reactive forms in all the soils and for all contaminating metals, whose mobility risk is increased by the generally very strongly acid to slightly acid soil reaction values. As regards pedodiversity, the heavy metal contamination clearly influenced quantity, quality and function of the soils. The morphological diversity of pedons, the taxonomic and functional pedodiversity and the soilscape pattern were all strongly affected, causing irreparable damage to the local economy and to the environment. This study highlights the need for the planning of remediation actions focused on the correct disposal and management of the mining residues at Montevecchio and can contribute in a significant way to set future environmental regulations. Copyright © 2012 John Wiley & Sons, Ltd.
MONITORING THE IMPACT OF SURFACE ALBEDO ON A SALINE LAKE IN SW RUSSIA
Authors: Argaman E. , Keesstra S. D. , Zeiliguer A.
Published: April 2012

Lake Elton is located east of the Volga River in Russia and covers an area of 155 km2. The hydrological system of the Lake and its surroundings are extremely vulnerable to climate change and human interference, but available local and regional information is sparse. Utilising climate data from 1987 to 2009 and surface albedo readings from the MODerate resolution Imaging Spectroradiometer satellite since 2000, this study analyses Lake degradation processes since 2005. Lake surface albedo analysis indicates that during the past 6 years, lake albedo has increased dramatically from average peak values of 0·14 to 0·40. In addition, air temperature has increased by 2 °C, and annual precipitation has decreased by 40 per cent. Moreover, human intervention in the area has increased environmental pressure on the Lake, causing a reduction of runoff inflow because of water capture, use of check‐dams and water‐harvesting systems. The results of the study show that, under current conditions, the Lake surface albedo is likely to remain high as compared with previous observations. The current trend implies an average 2 per cent per year increase in future annual albedo, with a maximum possible increase of 4 per cent up to a steady state of salt‐crust albedo values. Copyright © 2012 John Wiley & Sons, Ltd.
Nanomaterials for Ocular Drug Delivery
Authors: Liu Shengyan , Jones Lyndon , Gu Frank X.
Published: April 2012

Efficient drug delivery to the eye remains a challenging task for pharmaceutical scientists. Due to the various anatomical barriers and the clearance mechanisms prevailing in the eye, conventional drug delivery systems, such as eye drop solutions, suffer from low bioavailability. More invasive methods, such as intravitreal injections and implants, cause adverse effects in the eye. Recently, an increasing number of scientists have turned to nanomaterial‐based drug delivery systems to address the challenges faced by conventional methods. This paper highlights recent applications of various nanomaterials, such as polymeric micelles, hydrogels, liposomes, niosomes, dendrimers, and cyclodextrins as ocular drug delivery systems to enhance the bioavailability of ocular therapeutic agents.

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Synthesis of Luminescent Covalent–Organic Polymers for Detecting Nitroaromatic Explosives and Small Organic Molecules
Authors: Xiang Zhonghua , Cao Dapeng
Published: April 2012

Three porous luminescent covalent‐‐organic polymers (COPs) have been synthesized through self‐polycondensation of the monomers of tris(4‐bromophenyl)amine, 1,3,5‐tris(4‐bromophenyl)benzene, and 2,4,6‐tris‐(4‐bromo‐phenyl)‐[1,3,5]triazine by using Ni‐catalyzed Yamamoto reaction. All the COP materials possess not only high Brunauer–Emmett–Teller (BET) specific surface area of about 2000 m2 g−1, high hydrothermal stability, but also graphene‐like layer texture. Interestingly, COP‐3 and COP‐4 show very fast responses and high sensitivity to the nitroaromatic explosives, and also high selectivity for tracing picric acid (PA) and 2,4,6‐trinitrotoluene (TNT) at low concentration (<1 ppm). In short, the COPs may be a new kind of material for detecting explosives and small organic molecules.
Highly Efficient Ring‐Opening Reaction of Azlactone‐Based Copolymer Platforms for the Design of Functionalized Materials
Authors: Laquièvre Aurélie , Allaway Naomi S. , Lyskawa Joël , Woisel Patrice , Lefebvre Jean‐Marc , Fournier David
Published: April 2012

Azlactone‐based homopolymers and copolymers were successfully synthesized using the reversible addition–fragmentation chain transfer (RAFT) process. The functional monomer 2‐styryl‐4,4‐dimethylazlactone (SDA) was first homopolymerized in bulk then copolymerized with styrene, leading to (co)polymers with low polydispersity indices (PDI = 1.10–1.20). The reactive azlactone rings, located along the backbone of the copolymers were subjected to highly efficient ring‐opening reactions with functionalized primary amine derivatives incorporating a fluorescent (naphthalene) or an electrochemical (ferrocene) probes, a biological fragment (glutathione), a sugar unit (β‐cyclodextrin), or an oligomeric fluorinated moiety, leading to materials with various interesting properties.
Model Catalysts for Clarification of Active Site‐Polymer Relationship in Heterogeneous Olefin Polymerization
Authors: Taniike Toshiaki , Takahashi Shougo , Wada Toru , Tonosaki Kiwamu , Dwivedi Sumant , Terano Minoru
Published: April 2012

Model catalysts having specially designed active species on support surfaces were employed to understand relationships between the structure/state of active sites and their catalytic performances for two classes of industrial olefin polymerization catalysts: Ziegler‐Natta and Phillips catalysts. Propylene polymerization using a TiCl3/MgCl2 model Ziegler‐Natta catalyst clarified an important role of the Ti dispersion state for the polymer stereo & chemical structures. Model Phillips catalysts having monochromate and dichromate structures on silica support imparted knowledge that dinuclear species is more responsible for the production of α‐olefin comonomer in ethylene polymerization, thus giving more branched polyethylene.
Method Development for Determination of n‐Hexane Solvent Extractable Materials in Polyethylene Using FIPA
Authors: van Rensburg Quentin , Luruli Nyambeni , Sadiku Rotimi
Published: April 2012

Hexane extractables or soluble materials in polyethylene are generally determined using gravimetric methods. These methods are slow, labour intensive and use large amounts of solvents. In this study, an attempt is made to develop a method for determining hexane extractable materials in both low and linear low density polyethylene. The GPC hybrid instrument from Viscotek that utilizes flow injection polymer analysis (FIPA) technique was used. Three samples with different physical forms (viz: pellets, powder and film) were investigated in order to determine whether physical forms had an effect on the results. The results obtained from FIPA were then compared to those obtained using the standard ASTM extraction method. The general trends of FIPA results showed reasonably good correlation to those obtained using ASTM method. Further, it was found that powder (ground pellets) and film samples analysed using FIPA give similar results while significant differences amongst the different physical forms were noticed in the results obtained using gravimetric methods. This could shorten turnaround times considerably when compared to long sample preparation times needed for gravimetric analytical methods. Further comparison of results between FIPA and the ASTM methods, yielded positive and promising data, when the average percentages of soluble materials obtained with CRYSTAF were considered.
Polymer‐Drug Encapsulation using Various PEG‐ and Polypeptide‐Based Block Copolymer Micelles
Authors: Veeren Anisha , Bhaw‐Luximon Archana
Published: April 2012

Various novel di‐or tri‐block copolymers with hydrophilic PEG and/or polylysine in association with hydrophobic polycaprolactone segments namely PEG‐b‐PolyLys and PEG‐b‐PolyLys‐b‐PCL, have been synthesized and characterized. Poly(Lys‐g‐Glu)‐b‐PCL has been successfully synthesized where D‐gluconolactone was grafted on the NH2 group of PolyLys. These copolymers self‐assemble in water to form micelles in the size range 165 to 365 nm and CMC from 0.1 mg/ml to 2 mg/ml. Both micelle size and CMC showed a strong dependency on the hydrophobic chain length. The encapsulation of Ketoprofen and Rifampicin in the different copolymer families was assessed and encapsulation efficiency determined using UV Spectroscopy. The % drug loaded was found to depend on the interaction between drug and copolymer system. Both drugs showed chemical conjugation with PolyLys segment and physical entrapment in the PCL hydrophobic core. Higher encapsulation efficiency was obtained with Rifampicin (17–70%).
Chemistry, Morphology, Microtomography and Activation of Natural and Carbonized Tannin Foams for Different Applications
Authors: Pizzi A. (Tony) , Celzard A. , Fierro V. , Tondi G.
Published: April 2012

Tannin based rigid foams are natural network structures obtained by polycondensations of polyflavonoid tannins and furfuryl alcohol. These foams have a wide range of characteristics. Physical tests such as water absorption, compression resistance, direct flame behaviour and measure of foam cell dimensions were carried out for each foam sample. Tannin‐based rigid foams, prepared from 95% natural material, are suggested for replacing synthetic phenol‐formaldehyde foams in various applications. For that purpose, a few physical properties were measured: resistance to fire and chemicals, absorption of various liquids, permeability, thermal conductivity and mechanical (compressive and tensile) strength. The materials were also found to present good resistance to strong acid and bases, and to solvents. Finally, slightly anisotropic mechanical properties were measured. The materials present a brittle behaviour, whether tested in compression or traction; nevertheless, their strengths, as well as their thermal conductivities, are fully comparable with those of their phenolic counterparts. Carbonisation of polyflavonoid tannin‐formaldehyde‐furfuryl alcohol rigid foams was found by MALDI‐TOF to yield a tridimensional network in which polynuclear aromatic hydrocarbon chains of high molecular weight are covalently linked to some furan resin structures surviving carbonisation. Structure conservation on carbonisation extends to furanic structures derived by the self condensation of furfuryl alcohol which are integral part of the total network. Some complex, tridimensional structures derived by the rearrangement to polyaromatic hydrocarbons of polyflavonoid tannins, constituting of aromatic benzene and furane rings and some formaldehyde‐derived methylene bridges appear to be formed.
Oligomers of Phenolic‐Type Resin Derived from the Condensation of Phenol with Benzyl Chloride
Authors: Dunga Nangamso , Jumbam Ndze Denis
Published: April 2012

The direct condensation of phenol with benzyl chloride in the absence of a catalyst at high temperatures produced a light‐brown viscous oil. A sample was analyzed by NMR, HPLC‐ESI mass spectrometry and MALDI‐TOF revealing that it is composed of a complex mixture of different low molecular weight oligomers of the phenolic‐type resin. While a good number of the peaks could be assigned to specific structures, not all of the peaks could be identified.
Surface‐Initiated Reversible Addition Fragmentation Chain Transfer (RAFT) Polymerization of Styrene from Laponite Clay Surfaces
Authors: Chirowodza Helen , Weber Wolfgang , Hartmann Patrice , Pasch Harald
Published: April 2012

Surface‐initiated reversible addition fragmentation chain transfer polymerisation of styrene was conducted from the surface of Laponite clay particles. A new cationic chain transfer agent, 2‐(2‐(butylthio‐carbonothioylthio)propanoyloxy)‐N,N,N‐trimethylethanaminium iodide was synthesised and attached to the clay surface from which polymerisation was initiated. A free RAFT agent, ethyl 2‐(butylthiocarbonothioylthio)propanoate was added in solution to control the polymerisation of free polymer. The grafted and free polymer were then analysed by SEC to get insight into the polymerisation. The thermal stability of the polymer/clay nanocomposites and grafted clay particles was investigated by TGA.
Matrix‐Assisted Laser Desorption Ionization Mass Spectrometry of Synthetic Polymers
Authors: Mautjana Nare Alpheus , Pasch Harald
Published: April 2012

Matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry allows fast and efficient analysis of complex synthetic polymers which always exhibit varying degrees of polydispersity including molar mass distribution and chemical composition distribution. Most commonly used with a time‐of‐flight (TOF) mass analyzer, MALDI MS is the workhorse in polymer mass spectrometry and can be used to 1) identify homopolymers, 2) determine the endgroups of macromolecules, 3) elucidate polymerization mechanisms, 4) analyze copolymers, 5) determine molecular structures, and 6) determine absolute molar masses of oligomers. This paper gives an overview of the mentioned applications of MALDI MS in polymer analysis.
Statistical test planning for ultrasonic welding of dissimilar materials using the example of aluminum‐carbon fiber reinforced polymers (CFRP) joints
Authors: Balle F. , Eifler D.
Published: April 2012

This paper is focused on statistical test planning methods to increase process stability by means of reproducibility in comparison to a stepwise empirical variation of each process parameter during solid state joining as well as the significant reduction of experimental time and costs. The methodology will be presented for the specific challenges of ultrasonic welding. This pressure welding technology was investigated systematically for joining aluminum sheet metals to carbon fiber reinforced thermoplastic polymers (CFRP). In this study two aluminum wrought alloys were investigated to be welded onto CFRP with PA66 matrix. To evaluate suitable process parameters, the statistical model named “central composite design circumscribed (CCC)” was used to prove the weldability of the Al/CFRP‐joints. An important advantage of the CCC‐model is the description of the mutual dependence of the three central welding parameters: oscillation amplitude, welding force and energy in relation to the achievable mechanical properties of the joints. It allows the reduction of the number of necessary welds at a factor of seven in comparison to a conventional empirical investigation. All combinations of the welding parameters were proved in tensile shear tests. Additional microstructural analysis helped to understand the mechanical behaviour of ultrasonically welded hybrid joints in detail.
Diffusion bonding of transition structures for integral aluminium‐fibre reinforced polymer (FRP) compounds
Authors: Schimanski K. , von Hehl A. , Syassen F.
Published: April 2012

Components in hybrid design become more and more important in terms of their lightweight potential. In this context the demand for weight saving in aerospace leads to increasing numbers of applications of fibre composites for primary structural components. In consequence the use of FRP‐metal compounds is necessary. Within the investigations of the researcher group “Schwarz Silber” (FOR 1224) founded by the DFG (German Research Foundation) material optimised interface structures for advanced CFRP‐aluminium compounds are currently being studied. Within their work the researcher group focussed on three concepts realizing the transition structures: the usage of wires (titanium), foils (titanium) and fibres (glass fibre) as transition elements between CFRP and aluminium. For the connection of the aluminium sheet and the transition element die‐casting and laser beam welding are basically used. As a possible alternative to the both liquid phase processes a feasibility study haven been done focussing the solid state processes diffusion bonding. The experimental results show the high potential of this process in view of the transferable loads for integral transition structures.
Determination of local material properties of laser beam welded aluminium‐steel and aluminium‐titanium compounds
Authors: Barr A. , Hunkel M. , von Hehl A.
Published: April 2012

The combination of different metallic materials, such as aluminium and steel or aluminium and titanium, by firmly bonding via laser beam welding enables the production of customised hybrid lightweight designs with enhanced properties. Both weld geometry and local material behaviour, which are responsible for the final load characteristics of the compound, are influenced by the process parameters during welding. A novel approach of coupling process, microstructure and mechanical simulation, considering the development of weld geometry and local material conditions is intended to deliver a fast and reliable method for evaluating the quasi‐static strength of laser beam welded hybrid compounds. Besides the objective to promote a reduction of expensive welding experiments, the developed method can enhance the performance of hybrid structures as well as their lightweight potential for automotive and aircraft applications. The experimental determination of the local mechanical properties as the basis for the regarded simulation approach is an essential part of a running research project.
Ultrafine‐grained AA6014/AA5754 laminates produced by accumulative roll bonding (ARB)
Authors: Hausöl T. , Höppel H. W. , Göken M.
Published: April 2012

Laminates with alternating AA6014 and AA5754 layers are produced by accumulative roll bonding (ARB). Depending on the number of ARB cycles the microstructure and the mechanical properties are investigated. The microstructure is characterized by scanning electron microscopy and correlated to the local mechanical properties determined by nanoindentation experiments. The overall properties are derived by tensile testing. The ultrafine‐grained microstructure and the local mechanical properties alter with the layer composition. With increasing number of ARB cycles a much higher grain refinement is achieved within the AA5754 layers than in the AA6014 layers. The hardness of the individual layers develops similarly. On the macroscopic scale it is shown that the laminates are unifying the desired properties of the materials involved: high strength by a simultaneous suppression of the Portevin‐Le Châtelier effect, typically occurring in the AA5754 alloy.
Behaviour of a quasicrystalline strengthened Al‐alloy during compression testing
Authors: Markoli B. , Bončina T. , Zupanič F.
Published: April 2012

In this work, an Al‐Mn‐Be‐Cu alloy was prepared by vacuum induction melting and casting. The alloy was then remelted and gravitationally cast into cylindrical metallic dies with 2 mm, 4 mm and 8 mm diameters in order to obtain the quasicrystalline phase in the aluminium‐rich matrix. The samples with height‐to‐thickness ratio of 3:1 were tested using compression test at room temperature. The deformation rate was 0.001 s–1. The main objective was to study the behaviour of the alloy during compression tests to obtain information regarding its plastic deformability and fracture. The compression behaviour of 2‐mm and 4‐mm samples was almost identical. They could be deformed to more than 0.9 true strain without fracture. In the plastic region, true stress of approximately 450 MPa was attained, and almost no hardening was observed. Such behaviour can arise from a microstructure consisting of primary icosahedral quasicrystalline particles and the matrix composed of two‐phase eutectic‐like structure composed of lamellar icosahedral phase and Al‐rich solid solution. The 8‐mm sample contained a considerable fraction of crystalline intermetallic compound and much less quasicrystalline phase, fractured at approximately 0.4 true strain, and at the same time, its true strength was approximately lower for 10% than that of 2‐mm and 4‐mm‐samples.
Investigation of a new fibre metal laminate (FML) family on the base of Al‐Li‐Alloy with lower density
Authors: Antipov V.V. , Senatorova O.G. , Beumler T. , Ijpma M.
Published: April 2012

The hybrid Fiber Metal Laminate (FML) GLARE (Glass Laminate Aluminium Reinforced Epoxy) is applied effectively by Airbus instead of monolithic aluminum alloys for lowering of weight and increase of the damage tolerance capability on the largest civil aircraft A‐380. Standard GLARE contains thin aluminum sheets of 2024T3 (duralumin type) alloy, which is used usually as a skin alloy because it provides high fatigue and damage tolerance properties as well as a high ductility. One of advanced ways of further FML development is an application of thin sheets from processable Al‐Li Russian high‐modulus (E = 80 GPa) 1441 alloy with lower density (d = 2.60 g/cm3). This results in further weight saving but also to an increase of stiffness of the FML‐structure by 5–7%. Investigations and tests of coupons, components, joints and panels from 1441‐FML are carried out by Airbus, Russian and Dutch partners. Various resins and glass fiber types were also used. It was shown that generally 1441‐FML properties can be compared to Standard GLARE, i. e. an 1‐to‐1 substitution of the 2024 sheets into 1441 sheets is an option in order to obtain the full weight saving advantage due to the density effect.
Group Decision Makers' Preferences Modelling within the Goal Programming Model: An Overview and a Typology
Authors: Munro Michelle , Aouni Belaïd
Published: April 2012

The Goal Programming (GP) model is one of the first models that have been developed to deal with managerial decision‐making problems where several incommensurable and conflicting objectives are involved. The GP variants integrate the decision maker's preferences differently. This model has also been applied to group decision‐making situations. The aim of this paper is to propose a new typology based on preferences articulation of decision makers through the GP model. This typology is based on the articulation and the elucidation process of the group decision makers' preferences. Copyright © 2012 John Wiley & Sons, Ltd.
On B1 inhomogeneity correction of in vivo human brain glutamate chemical exchange saturation transfer contrast at 7T
Authors: Singh Anup , Cai Kejia , Haris Mohammad , Hariharan Hari , Reddy Ravinder
Published: April 2012

The effects of radio frequency field (B1) inhomogeneity on measured in vivo human brain glutamate chemical exchange saturation transfer contrast maps are normally confounded with contributions from chemical exchange saturation transfer, direct saturation and magnetization transfer effects. Consequently, the chemical exchange saturation transfer effect variation with B1 follows a complicated function and depends on the tissue types as well. In this work, we developed and tested a novel approach for B1 inhomogeneity correction based on acquiring calibration data at a coarsely sampled B1 values in conjunction with the measured B1 maps. With this approach, different calibration curves are derived for gray matter and white matter instead of a simple linear scaling based on local B1 values. Potential extensions of this approach to study chemical exchange saturation transfer contrast from other metabolites and tissue types are discussed. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
3‐T proton magnetic spectroscopy in unmedicated first episode psychosis: A focus on creatine
Authors: Tibbo Philip G. , Bernier Denise , Hanstock Christopher C. , Seres Peter , Lakusta Bonnie , Purdon Scot E.
Published: April 2012

Different lines of evidence suggest an abnormal cerebral energy metabolism as being critical to the pathophysiology of schizophrenia. However, it is unknown as to whether levels of creatine (Cr) would be involved in these anomalies. The study involved 33 unmedicated first episode psychosis patients and 41 healthy controls. Proton magnetic resonance spectroscopy (1H‐MRS) was performed at 3 T using a long TE (TE/TM/TR of 240/27/3000 ms) such that within the total phosphocreatine (PCr) plus Cr signal (tCr240), mainly Cr was detectable. The target region was an 18 cm3 prefrontal volume. A negative association was found between age of patients and tCr240 levels referenced to internal water, with 20% of the variance in tCr240 accounted for by Age. A secondary finding revealed 16% reduction of tCr240 levels in patients, solely when comparing participants older than the median age of patients. No association existed between tCr240 levels and clinical variables. These findings support previous data reporting abnormalities in brain creatine kinase isoenzymes involved with the maintenance of energy pools in schizophrenia. The implications of using a long TE are discussed in terms of the relative proportions of Cr and PCr within the tCr240 signal, and of potential group differences in T2 times. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
High‐resolution slice‐selective Fourier velocity encoding in congenital heart disease using spiral SENSE with velocity unwrap
Authors: Steeden Jennifer A. , Jones Alexander , Pandya Bejal , Atkinson David , Taylor Andrew M. , Muthurangu Vivek
Published: April 2012

Quantification of peak velocity is important in the assessment of stenotic flow jets in patients with congenital heart disease. Phase‐contrast magnetic resonance underestimates peak velocities. Hence, clinically Doppler ultrasound is used as the reference standard for assessing stenoses. It is possible to accurately measure peak velocity in MR using Fourier velocity encoding (FVE). In this study, a fast, high‐resolution slice‐selective FVE sequence was developed with the use of spiral trajectories, parallel imaging, and partial Fourier in the velocity dimension and a novel velocity‐unwrap technique. The resulting sequence was acquired within a short breath‐hold (more than 15 heartbeats) making this FVE technique clinically achievable. Peak velocities were compared from Doppler ultrasound, phase‐contrast magnetic resonance, and FVE. Experiments were carried out in vitro and in vivo in 25 patients with congenital heart disease with stenoses. It was shown that in vitro and in vivo phase‐contrast magnetic resonance tended to underestimate peak velocity when compared with Doppler ultrasound, whereas FVE agreed well with Doppler ultrasound. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Wrinkled and slack membranes: nonlinear 3D elasticity solutions via smooth DMS‐FEM and experiment
Authors: Sunilkumar N. , Lalmoni G. , Roy D. , Reid S. R. , Vasu R. M.
Published: April 2012

The smooth DMS‐FEM, recently proposed by the authors, is extended and applied to the geometrically nonlinear and ill‐posed problem of a deformed and wrinkled/slack membrane. A key feature of this work is that three‐dimensional nonlinear elasticity equations corresponding to linear momentum balance, without any dimensional reduction and the associated approximations, directly serve as the membrane governing equations. Domain discretization is performed with triangular prism elements and the higher order (C1 or more) interelement continuity of the shape functions ensures that the errors arising from possible jumps in the first derivatives of the conventional C0 shape functions do not propagate because the ill‐conditioned tangent stiffness matrices are iteratively inverted. The present scheme employs no regularization and exhibits little sensitivity to h‐refinement. Although the numerically computed deformed membrane profiles do show some sensitivity to initial imperfections (nonplanarity) in the membrane profile needed to initiate transverse deformations, the overall patterns of the wrinkles and the deformed shapes appear to be less so. Finally, the deformed profiles, computed through the DMS FEM‐based weak formulation, are compared with those obtained through an experiment on an ultrathin Kapton membrane, wherein wrinkles form because of the applied boundary displacement conditions. Comparisons with a reported experiment on a rectangular membrane are also provided. These exercises lend credence to the feasibility of the DMS FEM‐based numerical route to computing post‐wrinkled membrane shapes. Copyright © 2012 John Wiley & Sons, Ltd.
Novel adaptive meshfree integration techniques in meshless methods
Authors: Racz Donat , Bui Tinh Quoc
Published: April 2012

We propose two strategies of novel adaptive numerical integration based on mapping techniques for solving the complicated problems of domain integration encountered in meshfree methods. Several mapping methods are presented in detail that map a complex integration domain to much simpler ones, for example, squares, triangles or circles. The techniques described in the paper can be applied to both global and local weak forms, and the highly nonlinear meshfree integrands are evaluated with controlled accuracy. The necessity of the clumsy procedure of background mesh or cell structures used for integration purpose in existing meshfree methods is avoided, and many meshfree methods that require the domain integration can now become ‘truly meshfree’. Various numerical examples in two dimensions are considered to demonstrate the applicability and the effectiveness of the proposed methods and it shows that the accuracy is improved significantly. Their obtained results are compared with analytical solutions and other approaches and very good agreements are found. Additionally, some three‐dimensional cases applied by the present methods are also examined. Copyright © 2012 John Wiley & Sons, Ltd.
Effects of an uncertainty management intervention on uncertainty, anxiety, depression, and quality of life of chronic obstructive pulmonary disease outpatients
Authors: Jiang Xiaojian , He Guoping
Published: April 2012

In this controlled, randomized study we explored the effects of an uncertainty management intervention on uncertainty, anxiety, depression, and quality of life (QOL) of chronic obstructive pulmonary disease (COPD) outpatients in China. Ninety‐six COPD outpatients completed the study (n = 49 in the intervention group; n = 47 in the control group). Over the 10‐month study duration, the intervention group received a cognitive behavioral intervention. Compared with the control group, the intervention group showed significant improvement in uncertainty, coping strategy, anxiety, depression, and the mental health domains of QOL after the intervention, providing the first evidence that uncertainty management can improve the emotional status and QOL of COPD outpatients. © 2012 Wiley Periodicals, Inc. Res Nurs Health 35:409–418, 2012
Measuring patient–provider trust in a primary care population: Refinement of the health care relationship trust scale
Authors: Bova Carol , Route Paulette Seymour , Fennie Kristopher , Ettinger Walter , Manchester Gertrude W. , Weinstein Bruce
Published: April 2012

Accurately measuring trust between patients and health care providers is important because low patient–provider trust can lead to poor treatment adherence and negative health outcomes. To measure patient–provider trust, we developed the Health Care Relationship (HCR) Trust scale. Findings from our initial use of the scale suggested the need to examine the scale's psychometric performance in a larger sample of adults with various chronic health conditions. We therefore examined the psychometric properties of the HCR Trust Scale in a random sample of adult primary care patients. Thirteen of the original 15 items fit the data best; a single‐factor structure explained 67% of the variance in patient–provider trust. The Cronbach's alpha for the 13‐item HCR Trust Scale—Revised was .96. © 2012 Wiley Periodicals, Inc. Res Nurs Health 35:397–408, 2012
Congressional response to public crisis: how corporations can prepare
Authors: Frulla David E.
Published: April 2012

Public policy is at the heart of US congressional investigations, where private corporations can confront a unique set of rules and mores—in a very public forum, often covered in the news and televised. This article traces the historical precedents to congressional inquiries, highlighting cases such as the ‘Teapot Dome’ scandal and the ensuing US Supreme Court case, McGrain v. Daugherty, confirming the Legislative Branch's independent investigative authority to compel a witness to testify and produce documents. The article explains the two types of congressional investigations, oversight and legislative, and how their differences could impact the corporations involved. It reviews recent examples of investigations, illuminating how a corporation's public relations and legal rights can both overlap and point to differing interests. Based upon first‐hand experience, the author provides a legal perspective in explaining the investigation procedures, the legal limits to congressional authority, and the steps taken to prepare a witness for testimony. Finally, the author explains how readiness for congressional inquiries is an integral aspect of prudent risk management for any major corporation. Copyright © 2012 John Wiley & Sons, Ltd.