bluuebunny/crossref_metadata_2025 huggingface dataset:
The ‘fresh start’ for individual debtors: social, moral and practical issues
Authors: van Apeldoorn Jan C.
Published: April 2008

The concept of a “fresh start” for individual debtors has been introduced in the Netherlands in 1998. Until then a natural person could be pursued for the debts he could not pay indefinitely. Their position was not different from the unfortunate debtors in many European countries to day. The entrance to the “fresh start‐ procedure” in the Netherlands is surrounded by impediments, the access is linked to the debtor in good faith, but after three years the fresh start comprises all debts (except student loans), none excluded. In the United States the fresh start doctrine is long established law, the entrance is easy, but many debts may be excluded. Because of public dissatisfaction in both countries the concept has changed. In the Netherlands many debts may now be excluded from the fresh start and in the United States a means test has been introduced. The two concepts of a fresh start for the natural person in both countries, originally so differnt in approach, now converged. Will the twain meet? Copyright © 2008 John Wiley & Sons, Ltd.
Nephrotoxicity induced by N‐(3,5‐dichlorophenyl)‐3‐hydroxysuccinamic acid in male and female Fischer 344 rats
Authors: Rankin Gary O. , Hong Suk‐kil , Anestis Dianne K.
Published: April 2008

The agricultural fungicide N‐(3,5‐dichlorophenyl)succinimide (NDPS) is a more potent nephrotoxicant in female rats than in males. Similarly, nephrotoxicant NDPS metabolites studied to date in male and female rats have also demonstrated gender differences, being twice as potent as nephrotoxicants in females as in males. The purpose of this study was to examine the nephrotoxic potential of N‐(3,5‐dichlorophenyl)‐3‐hydroxysuccinimide (3‐NDHSA) in male and female Fisher 344 rats to determine if gender differences in nephrotoxic potential also exist for this metabolite. Rats (four per group) were administered a single intraperitoneal (i.p.) injection of 3‐NDHSA (0.1, 0.2 or 0.4  mmol kg−1) or vehicle, and renal function was monitored at 24 and 48 h. 3‐NDHSA 0.1 mmol kg−1 did not induce nephrotoxicity in male or female rats. In male rats, 3‐NDHSA 0.2 mmol kg−1 induced mild nephrotoxicity seen as diuresis and transient, mild proteinuria. However, 3‐NDHSA 0.4 mmol kg−1 induced marked nephrotoxicity. In female rats, 3‐NDHSA 0.2 mmol kg−1 induced mild nephrotoxicity, as evidenced by transient diuresis and proteinuria. As in males, 3‐NDHSA 0.4 mmol kg−1 induced marked nephrotoxicity. These results indicate that, unlike NDPS and other nephrotoxic NDPS metabolites, 3‐NDHSA does not exhibit gender differences in nephrotoxic potential. In addition, in comparison with NDPS and other nephrotoxic NDPS metabolites, 3‐NDHSA is a less potent nephrotoxicant that NDHS or 2‐NDHSA and similar to NDPS in nephrotoxic potential in male rats. Copyright © 2008 John Wiley & Sons, Ltd.
Biochemical and enzymatic changes after black scorpion Heterometrus fastigiousus Couzijn envenomation in experimental albino mice
Authors: Chaubey Mukesh Kumar , Upadhyay Ravi Kant
Published: April 2008

The toxic effects of Asian black scorpion Heterometrus fastigiousus (Family, Scorpionidae) venom were determined in albino mice (NIH strain). Venom was isolated and fractioned by Sepharose CL‐6B column chromatography. The toxicity of fractioned venom was determined in albino mice by subcutaneous envenomation. The LD50 of venom was found to be 15 mg kg−1 body weight and range of molecular weight of venom proteins responsible for toxicity was found from 9.5–63 kDs. The effects of fractioned venom on different biochemical and enzymatic parameters in blood serum and gastrocnemius muscle tissue of albino mice were determined after experimental envenomation. An increase in serum levels of glucose, free amino acids, uric acid, pyruvic acid and total protein was observed while a decrease in the cholesterol level in serum was observed after 4 h of envenomation. Increase in alkaline phosphatase (ALP), acid phosphatase (ACP), lactic dehydrogenase (LDH) and glutamate–pyruvate transaminase (GPT) enzyme activity in serum was observed. Glycogen content in liver, atria, ventricle, rectus abdominus and gastrocnemius muscle was decreased after experimental envenomation. Activity of ALP, ACP, LDH, GPT, AChE and Na+K+ATPase enzymes in gastrocnemius muscle tissue of envenomed albino mice was studied. Inhibition in ALP, AChE and Na+K+ATPase enzyme activity and increase in ACP, LDH and GPT enzyme activity was observed in gastrocnemius muscle after scorpion envenomation. In vitro studies with AChE and Na+K+ATPase enzymes indicated that enzymatic activity of AChE was inhibited competitively by fractioned venom in gastrocnemius muscle. Copyright © 2008 John Wiley & Sons, Ltd.
The induction of cytochrome P450 1A1 by Sudan Dyes
Authors: Ahmed Refat Nahla A. G. , Ibrahim Zein Shaban , Moustafa Gihan Gamal , Sakamoto Kentaro Q. , Ishizuka Mayumi , Fujita Shoichi
Published: April 2008

Azo dyes form a major class of chemically related compounds that are ubiquitous in foods, paints, printing inks, cosmetics, and also used as biological stains in histological and histopathological laboratories and clinics. Sudan I, sudan III, and sudan IV have been classified as category 3 carcinogens by International Agency for Research on Cancer. In this study, we investigated the difference between these three sudan dyes in induction of CYP1A1. We intraperitoneally treated Wistar rats with each of the three sudan dyes (I, III, and IV) for 3 days. Treatment of Wistar rats with sudan I produced the highest induction of CYP1A1 protein and mRNA whereas treatment of Wistar rats with sudan III produced about two third of CYP1A1 protein and mRNA than induced by sudan I. Furthermore, treatment of Wistar rats with sudan IV produced the lowest induction of CYP1A1 protein and mRNA which is about two third of that induced with sudan III treatment. We further investigated the effect of these sudan dyes on CYP1A1 transcription through investigating the xenobiotic response element (XRE) reporter activity in HepG2. The XRE reporter activity study showed the same trend of activity of sudan dyes comparable to the effects on CYP1A1 mRNA and protein. Immunohistochemical study revealed a differential pattern of distribution of CYP1A1 protein in rat liver among the three sudan dyes, apparent in the centrilobular and midzonal region with sudan III, progressing to panlobular with sudan I, whereas sudan IV showed a reversal of pattern of induction with the most intense staining in the periportal region. Our results suggest that there is an inverse relationship between the molecular size of the three sudan dyes and their ability to induce CYP1A1. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:77–84, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20220
Induction of drug metabolism enzymes and transporters by oltipraz in rats
Authors: Merrell Matthew D. , Augustine Lisa M. , Slitt Angela L. , Cherrington Nathan J.
Published: April 2008

Coordinate regulation of Phase‐I and ‐II enzymes with xenobiotic transporters has been shown after treatment with microsomal enzyme inducers. The chemopreventive agent oltipraz (OPZ) induces Phase‐I and ‐II drug‐metabolizing enzymes such as CYP2B and NQO1. The purpose of this study was to examine the regulation of drug‐metabolizing enzymes and transporters in response to OPZ treatment and to investigate a potential role for constitutive androstane receptor (CAR) in OPZ‐mediated induction. Sprague‐Dawley rats treated with OPZ exhibited increased mRNA and protein levels of both Nqo1 and Cyp2b1/2 by 24 h. To examine whether OPZ activates transporter gene expression via CAR, sexually dimorphic male and female Wistar‐Kyoto (WKY) rats were treated with OPZ and mRNA levels quantified by bDNA signal amplification. OPZ induced Ugt1a6 and Ugt2b1 in males significantly higher than in females, indicating a CAR‐dependent mechanism of induction. However, OPZ induced microsomal epoxide hydrolase, NAD(P)H quinone oxidoreductase, and Cyp3a1/23 equally in both genders, indicating a CAR‐independent mechanism of induction of these genes. Similarly, the transporters Mdr1a, Mdr1b, Mrp3, and Mrp4 were induced by OPZ without any apparent difference between genders. In summary, OPZ coordinately increases multiple hepatic xenobiotic transporter mRNA levels, along with Phase‐I and ‐II enzymes some of which may occur through CAR‐dependent mechanisms. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:128–135, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20225
Age‐related changes to tumor necrosis factor receptors affect neuron survival in the presence of beta‐amyloid
Authors: Patel Jigisha R. , Brewer Gregory J.
Published: April 2008

Inflammation including local accumulations of tumor necrosis factor alpha (TNF‐α) is a part of Alzheimer's disease pathology and may exacerbate age‐related neurodegeneration. Most studies on TNF‐α and TNF neuronal receptors are conducted by using embryonic neurons. Few studies consider age‐related deficits that may occur in neurons. Age‐related changes in susceptibility to TNF‐α through TNF receptor 1 (TNFR1) and receptor 2 (TNFR2) expression could increase susceptibility to β‐amyloid (1–42, Aβ42). Evidence is conflicting about which receptor mediates survival and/or apoptosis. We determined how aging affects receptor expression in cultured adult rat cortical neurons. Old neurons were more susceptible to Aβ42 toxicity than middle‐aged neurons, and the addition of TNF‐α was neuroprotective in middle‐aged neurons, but exacerbated the toxicity from Aβ42 in old neurons. These pathologic and protective responses in old and middle‐aged neurons, respectively, correlated with higher starting TNFR1 and TNFR2 mRNA levels in old vs. middle‐aged neurons. Middle‐aged neurons treated with TNF‐α plus Aβ42 did not show an increase in either TNFR1 or TNFR2 mRNA, but old neurons showed an up‐regulation in TNFR2 mRNA and not TNFR1 mRNA. Despite these mRNA changes, surface immunoreactivity of both TNFR1 and TNFR2 increased with the dose of TNF‐α in middle‐aged neurons. However, middle‐aged neurons treated with TNF‐α plus Aβ42 showed an up‐regulation in both TNFR1 and TNFR2 surface expression, whereas old neurons failed to up‐regulate surface expression of either receptor. These findings support the hypothesis that age‐related changes in TNF‐α surface receptor expression contribute to the neuronal loss associated with inflammation in Alzheimer's disease. © 2008 Wiley‐Liss, Inc.
Autologous synovial fluid enhances migration of mesenchymal stem cells from synovium of osteoarthritis patients in tissue culture system
Authors: Zhang Sheng , Muneta Takeshi , Morito Toshiyuki , Mochizuki Tomoyuki , Sekiya Ichiro
Published: April 2008

Synovial fluid from osteoarthritic knee contains mesenchymal stem cells (MSCs). One of the possible reservoirs of MSCs in synovial fluid is synovial tissue, and synovial fluid may induce mobilization of MSCs into synovial fluid in osteoarthritis patients. Here, we investigated whether synovial fluid expanded synovial MSCs in a tissue culture system. Human synovium and synovial fluid were obtained from osteoarthritis patients during total knee arthroplasties. In the tissue culture system, autologous synovial fluid expanded synovial cells statistically higher than αMEM + FBS, and the addition of TGFβ3 to αMEM + FBS increased expansion to a similar level in all 11 donors. The addition of decorin or anti‐TGFβ neutralizing antibody to synovial fluid partially inhibited synovial cell expansion. In cell culture assay, synovial fluid proliferated synovial cells fewer than αMEM + FBS. The expanded synovial cells in synovial fluid retained multipotentiality and showed surface markers similar to those of MSCs. We demonstrated that autologous synovial fluid enhanced expansion of MSCs in tissue culture of synovium from osteoarthritis patients by promoting cell migration. This effect was partially affected by TGFβ. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1413–1418, 2008
Subcellular distribution of the insulin‐like growth factor (IGF) binding proteins (IGFBPs) 2 and 3 in articular chondrocytes
Authors: Sun Tiezheng , Hunziker Ernst B. , Morales Teresa I.
Published: April 2008

The insulin‐like growth factor (IGF) is a major anabolic regulator in articular cartilage. The IGF‐binding proteins (IGFBPs) are increased during osteoarthritis (OA), but the function of the later proteins remains unknown. In general, the IGFBPs are pluripotential effectors capable of IGF regulation and of acting on their own to control key cell functions, including survival and proliferation. The independent functions are often associated with their cell location, and therefore this study explores the distribution of IGFBP‐2 and IGFBP‐3 in articular chondrocytes. Immunohistochemistry was used to localize IGFBP‐2 in normal human articular cartilage. Bovine chondrocytes were used for subcellular fractionation (hypotonic cell lysis) under nonreducing conditions and nuclear purification (centrifugation on sucrose cushions). Cell fraction markers and IGFBPs were assayed in the subcellular fractions by Western immunoblot. The IHC results showed association of IGFBP‐2 with chondrocytes, but not with the nuclei. Subcellular fractionation of isolated chondrocytes yielded intact nuclei as assessed at the light microscopic level; the nuclear marker histone H1 was exclusively associated with this fraction. More than 90% of the cytoplasmic marker GAPDH and all the detectable IGFBP‐2 were in the cytoplasmic fraction. Immunoreactive IGFBP‐3 was found in the cytoplasmic and peri‐nuclear/nuclear fractions. Chondrocytes contain intracellular IGFBP‐2 and IGFBP‐3 but only IGFBP‐3 is associated with nuclei. This suggests the hypothesis that the actions of these IGFBPs in articular cartilage extend beyond the classic modulation of IGF receptor action. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1421–1427, 2008
Branching out: Social identity comes to the forefront
Authors: Hannum Kelly M.
Published: April 2008

For leaders, the issue of social identity—the parts of a person's identity that come from belonging to particular groups, including those based on age, ethnicity, race, religion, gender, sexual orientation, nationality, and socioeconomic status—is becoming increasingly important in the way they lead. The social identities of those around you affect how they view you as a leader and how they view, and thus work with, others. Leaders can use an understanding of social identity to decrease their likelihood of misunderstanding others, increase their openness to different perspectives, and enhance their skill at accurately interpreting situations that call on their ability to lead.
Stabilization in Water of Polymer/Cu2+ Complexes Using Poly(sodium acrylate)‐graft‐poly(N,N‐dimethylacrylamide) Graft Copolymers
Authors: Iatridi Zacharoula , Bokias Georgios
Published: April 2008

The formation of complexes between Cu2+ ions and graft copolymers built from a PANa backbone and non‐ionic hydrophilic PDMAM side chains is investigated by means of turbidimetry, viscometry, DLS, ζ‐potential measurements, and UV‐vis spectrophotometry. The macroscopic phase separation which accompanies complexation is gradually depressed with increasing PDMAM content x, and water‐soluble complexes are formed for x = 70 mol‐%. The polymer/Cu2+ complexation is a charge neutralization process that leads to the formation of water‐soluble, compact, hybrid polymer/metal ion nanostructures. UV‐vis data indicate that this graft copolymer could possibly serve as a water‐soluble sensor for Cu2+ ions.

magnified image
Diastereotopic Styrene Arrangement in the Heterosequences of Random Styrene‐Ethylene Copolymers
Authors: Longo Pasquale , Napoli Mariagrazia , Ricciardi Rosa
Published: April 2008

Random styrene‐ethylene copolymers have been synthesized by the hydrogenation of styrene‐butadiene copolymers. The samples were characterized by 13C NMR spectroscopy, X‐ray powder diffraction, thermal analysis, and Fourier transform IR (FTIR) spectroscopy. In the 13C NMR spectra, the resonance of the methylene carbon next to a methine bearing a phenyl group presents splitting due to its diastereotopic positions with respect to the phenyl substituents of the second and third inserted styrene units. A definitive assignment of the resonances of the SEES sequences (S = styrene, E = ethylene) was obtained by synthesis of a suitable model compound: 5,10‐diphenyl‐pentadecane. X‐ray powder diffraction and thermal analysis show that these samples are amorphous. This is probably due to the shortness of the ethylene and styrene sequences in the copolymers. DSC thermograms show a single glass transition, at a intermediate temperature, between the Tg values of polystyrene and polyethylene, depending on the styrene content in the chain. FTIR spectra indicate the presence of styrene sequences in an isotactic arrangement.

magnified image
Synthesis of Novel Rod‐Coil Amphiphilic Block Copolymers PAA‐b‐DPS with Fréchet‐Type Dendronized Polystyrene and Poly(acrylic acid)
Authors: Yi Zhuo , Zhang Yanhong , Chen Yongming , Xi Fu
Published: April 2008

A series of well‐defined rod‐coil PAA‐b‐DPS block copolymers, containing Fréchet‐type dendronized polystyrene (DPS) with different generation as a rod‐like hydrophobic block and poly(acrylic acid) (PAA) as a hydrophilic coil were synthesized. The procedure included the following steps: the precursor PMA‐b‐DPS copolymer was prepared through ATRP of Fréchet‐type dendritic styrene macromonomer bearing the first to the third generation (G1–G3), respectively, initiated by poly(methyl acrylate) (PMA‐Br). Then, by converting PMA into PAA by subsequent hydrolysis, the targeted amphiphilic copolymers were obtained. Moreover, by using the rod‐coil amphiphiles as building blocks, large compound micelles and vesicles were formed in a binary solvent mixture of DMF/H2O. Morphological changes in self‐assembly showed dependence on the length of the dendronized block.

magnified image
Overview – Superplasticity Community
Authors: Curtis R.V.
Published: April 2008

The overview starts with the background behind the creation of the European Superplasticity Community and its current activities, before moving on to a more detailed description of the UK’s IOM3 Superplasticity Committee and its terms of reference.

A short history of the commercial development of the process is included which describes in images some of the key advances and applications of superplastic forming in some of its main markets, particularly with respect to the uses of commercial aluminium and titanium alloys.

This overview then briefly relates the practical phenomenon of superplasticity, particularly with reference to metallic materials, but not exclusively, to the mechanisms by which large plastic elongations are observed. A new focussed ion beam etching technique is being adopted at the University of Oxford to provide physical scientists with new evidence on which to base their models for the mechanisms of superplasticity.

Some potential applications of superplastic forming are then explored in the medical and dental sectors including the use of ceramic die materials for the manufacture of dental and maxillofacial prostheses and some results on the biocompatibility of as‐formed titanium alloys will be presented.

A section on bulk metallic glasses (BMG’s) explains some of the similarities and differences between large deformation in BMG’s and crystalline superplastic materials. Some interesting results with Zr44Ti11Cu10Ni10Be25 are described.

Two superplasticity standards have been published in the last few years that specify how the superplastic properties of materials should be measured. Before the ISO standard was published extensive changes were recommended by the UK working party, all of which were accepted. Now, the British Standards Institute have made the IOM3 Superplasticity Committee a sub panel of ISE/NFE/04/01 – the BSI committee concerned with the uniaxial testing of metals. The new panel advising on superplasticity measurement related to standards has the reference ISE/NFE/04/01/04 i.e. ‘panel 4.’

Finally, the future of superplastic forming will be explored following a potentially significant development using laser technology
Grain refinement process in commercial 7075‐T6 aluminum alloy under friction stir welding and superplasticity
Authors: Motohashi Y. , Sakuma T. , Goloborodko A. , Ito T. , Itoh G.
Published: April 2008

About the influence of substrate roughness and spray particle size on the adhesion of thermal spray coatings

Process of grain refinement taking place during friction stir welding of a 7075‐T6 Al alloy was studied. It appears that the fine‐grained structure is formed by the grain fragmentation process, i.e., grains split by the development of internal boundaries with medium to high angle misorientations, mainly caused by dynamic recrystallization, followed by the evolution of new fine grains. The fine‐grained alloy shows superplasticity at around 673K at strain‐rate of 1×10‐3s‐1.

Keywords: High strength aluminum alloy; Friction stir welding; Grain refinement; Continuous dynamic recrystallization
Recovery and recrystallization in the superplastic deformation of AA5182
Authors: Chen Z. , Kazantzis A.V. , De Hosson J.Th.M.
Published: April 2008

The coarse‐grained Al alloy AA5182 exhibits poor superplasticity with a maximum elongation to failure not exceeding 220 % at 450 °C and at 10‐2 s‐1. The low values of the strain rate sensitivity indicate that the dislocation velocity is quite high and necking is developed quite soon during extension. The size (often exceeding 1 μm) and the distribution of the precipitates render them incapable of pinning the subgrain boundaries efficiently. As a result recovery and reconstruction by grain refinement occurs only within the necking region where the applied stress is concentrated. A fabrication method which will be able to introduce a large number of submicron sized precipitates will most likely result in sufficient pinning of the subgrain boundaries. This will promote recovery and reconstruction to take place more uniformly in the material rendering it appreciably superplastic.
Manufacture of Titanium implants
Authors: Klose J. , Rehtanz E. , Rothe C. , Eulitz I. , Güther V. , Beck W.
Published: April 2008

Titanium is characterized by low density and excellent biocompatibility. Furthermore, Titanium based alloys feature a high strength. Due to this combination of properties Titanium and Titanium based alloys are increasingly used by medical technique. TiAl6V4 as an (α+β)‐alloy can only be formed substantially at high temperatures due to the limited deformation ability of the α‐phase. Titanium’s capability to dissolve several percent of oxygen causes difficulties at heat treatment and hot forming especially in thin dimensions. Alternative solutions and methods of resolution are being discussed. Based on a strip manufacturing process a cold rolled strip can be produced for specific applications. The process is mainly applicable to produce a cold rolled strip suitable for superplastic forming. For this purpose the superplastic forming was adapted to the new strip material. The cold rolled TiAl6V4‐strip exhibits a technically interesting area for superplastic forming. Formation of the microstructure and mechanical properties are being explained. On the basis of these results a first prototype shell of a pacemaker case was manufactured from the specific cold rolled TiAl6V4‐strip by superplastic forming. The results demonstrate the possibility to manufacture pacemaker cases with equable properties.
Failure prediction for Titanium alloys using a superplastic forming limit diagram approach
Authors: Leen S.B. , Kröhn M.A. , Hyde T.H.
Published: April 2008

Superplastic forming limit diagrams (SPFLDs) are presented for both Ti‐6Al‐4V and Ti‐6Al‐2Sn‐4Zr‐2Mo alloys. FE‐predictedϵ1‐ϵ3‐ϵeqpaths for key points on the forming blank are then plotted on the SPFLD to predict failure. A key factor for reliable SPF forming limit prediction is the incorporation of a mechanisms‐based constitutive model, which includes microstructural effects, such as static and dynamic grain growth and associated hardening, and with material constants independent of the forming strain‐rate. The sinh model of Dunne and co‐workers is thus employed. Results from forming trials for both materials are used to assess the failure predictions.
Superplasticity and high temperature deformation behaviour in nano grain Tungsten compacts
Authors: Ameyama K. , Oda E. , Fujiwara H.
Published: April 2008

Nano grain tungsten is fabricated by Mechanical Milling (MM) process, and its grain growth behavior and high temperature deformability is investigated. As a result, a nano grain structure, whose grain size is approximately 20 nm or less, is obtained after MM for 360ks. Those nano grains demonstrate an irregular grain boundary structure, i.e., “non‐equilibrium grain boundary”, and they change to a smooth grain boundary structure by annealing at 1023 K for 3.6 ks. Compacts with nano grain structure indicate superior sintering property even at 1273 K (0.35 Tm). Rhenium addition prevents grain growth during sintering and thus the compacts indicate a further improvement in deformability. The compact is composed of equiaxed grain, whose grain size is 420 nm, and has low dislocation density even after the large deformation. The strain rate sensitivity, i.e., m‐value, of 0.41 is obtained in the W‐Re compact at 1473 K. Those results strongly imply that the nano grain W‐Re compacts show superplasticity at less than half of the melting temperature, i.e., 1473 K (0.42 of the solidus temperature).
Magnesium tube hydroforming
Authors: Liewald M. , Pop R.
Published: April 2008

Magnesium alloys reveal a good strength‐to‐weight ratio in the family of lightweight metals and gains potential to provide up to 30 % mass savings compared to aluminium and up to 75 % compared to steel. The use of sheet magnesium alloys for auto body applications is however limited due to the relatively low formability at room temperature.

Within the scope of this paper, extruded magnesium tubes, which are suitable for hydroforming applications, have been investigated. Results obtained at room temperature using magnesium AZ31 tubes show that circumferential strains are limited to a maximal value of 4 %. In order to examine the influence of the forming temperature on tube formability, investigations have been carried out with a new die set for hot internal high pressure (IHP) forming at temperatures up to 400 °C. Earlier investigations with magnesium AZ31 tubes have shown that fractures occur along the welding line at tubes extruded over a spider die, whereby a non‐uniform expansion at bursting with an elongation value of 24 % can be observed. A maximum circumferential strain of approx. 60 % could be attained when seamless, mechanically pre‐expanded and annealed tubes of the same alloy have been used. The effect of annealing time on materials forming properties shows a fine grained structure for sufficient annealing times as well as deterioration with a large increase at same time. Hence, seamless ZM21 tubes have been used in the current investigations. With these tubes, an increased tensile fracture strain of 116 % at 350 °C is observed as against 19 % at 20 °C, obtained by tensile testing of milled specimens from the extruded tubes. This behaviour is also seen under the condition of tool contact during the IHP forming process. To determine the maximum circumferential strain at different forming temperatures and strain rates, the tubes are initially bulged in a die with square cross‐section under plane stress conditions. Thereafter, the tubes are calibrated by using an optimised pressure‐time curve. The IHP forming process has also been used to demonstrate practicability and feasibility for real parts by manufacturing a technology‐demonstrator part using the magnesium alloy ZM21.
A pilot study of self‐monitoring urine flow in people with long‐term urinary catheters
Authors: Wilde Mary H. , Brasch Judith
Published: April 2008

Self‐monitoring of urine flow may be beneficial in preventing catheter‐related problems. An intervention was pilot tested using a single group design with 11 individuals over 6 months. Feasibility of the intervention, performance of new measures (awareness, self‐monitoring, and self‐ management of urine flow), and health outcomes were assessed. The intervention was well received by participants, none of whom withdrew voluntarily from the study. All data were collected at intake, and bimonthly at 2, 4, and 6 months. Nine of 11 participants reported that the intervention had helped them to pay attention to fluid intake. Episodes of UTI decreased over the course of the intervention, with the greatest drop between 2 and 4 months. © 2008 Wiley Periodicals, Inc. Res Nurs Health 31:490–500, 2008
Microcombustion calorimetry as a tool for screening flame retardancy in epoxy
Authors: Morgan Alexander B. , Galaska Mary
Published: April 2008

Through the use of microcombustion calorimetry several polymer nanocomposite, flame retardant (FR), and polymer nanocomposite + FR systems were screened for flammability performance. The use of this technique allowed for the creation of small batch (less than 50 g) epoxy formulations as compared to 400–500 g needed for cone calorimeter testing of epoxy + fiberglass panels. The results from the microcombustion calorimeter screening suggested that the system with the best flammability performance was a combination of organophosphonate and zinc borate, and not one of the polymer nanocomposite systems. This best candidate was then scaled up and fabricated into a fiberglass‐reinforced composite which was further tested by a cone calorimeter. This paper shows some of the correlations between the microcombustion and cone calorimeter results for this single sample, provides some reasons for why the polymer nanocomposite samples did not provide the best results in flammability reduction, and suggests some caveats when using microcombustion calorimetry as the only screening tool for flammability. Copyright © 2008 John Wiley & Sons, Ltd.
pH sensor based on polyaniline and aniline–anthranilic acid copolymer films using quartz crystal microbalance and electronic absorption spectroscopy
Authors: Ayad M. M. , Salahuddin N. A. , Abou‐Seif A. K. , Alghaysh M. O.
Published: April 2008

The pH sensitivity based on conducting polyaniline (PANI) and copolymer of aniline and o‐anthranilic acid (AA) films were studied using quartz crystal microbalance (QCM) technique and UV–Vis spectroscopy. The sensor was constructed from these polymer films coated on the electrode of the QCM. The resonant frequency changes as a function of pH in the range of 2–12 were measured. These changes are quantitative indication of the degree of dedoping or redoping of the polymer films upon the subsequent exposure of the electrode to 0.25 M sulfuric acid and different pH solutions. There are two linear regressions between the frequency change and pH with two different and opposite slopes in the regions from 2 to 9 and 9 to 12. The pH sensitivity of the copolymer film was found to be less than using the PANI film. Thin films of PANI and copolymer, which were chemically polymerized in a sulfuric acid solution, were deposited onto the inner walls of the quartz cuvettes. The UV–Vis absorption spectra of these films were measured in different pH solutions. Relations between the maximum absorption and its wavelength versus pH were constructed. The copolymer film shows some advantages over the PANI film. The difference between the PANI and copolymer films as pH sensors using the QCM and electronic absorption extends from the determination of pKa for both films. Copyright © 2008 John Wiley & Sons, Ltd.
Monitoring of beet armyworm resistance to spinosad and methoxyfenozide in Mexico
Authors: Osorio Aniceto , Martínez Ana M , Schneider Marcela I , Díaz Ovidio , Corrales José L , Avilés Mayra C , Smagghe Guy , Pineda Samuel
Published: April 2008

BACKGROUND: Resistance to spinosad and methoxyfenozide has been studied in several insect pests, but there is a lack of information on Spodoptera exigua (Hübner) in Mexico. Therefore, evidence for the development of resistance in this pest to both compounds was examined. The effects of methoxyfenozide on reproductive parameters of S. exigua adults were also determined.

RESULTS: Third instars from a field population were exposed for 24 h to the LC50 of spinosad or methoxyfenozide for over six generations (G2–G7). No significant reduction in susceptibility to either compound was detected for up to five generations. In G7, LC50 values for insects exposed to spinosad and methoxyfenozide were respectively 2.75‐fold and 1.25‐fold greater than for G1 larvae. Oral treatment with methoxyfenozide reduced the fecundity and fertility of G7 adults, confirming sublethal effects on reproduction. Finally, five populations (Se‐La Floriza, Se‐Lazareto, Se‐Bachigualato, Se‐Los Agustinos and Se‐Villa de Arista) of S. exigua were collected from fields in three states of Mexico for resistance monitoring to spinosad and methoxyfenozide. With the exception of Se‐Villa de Arista, the other populations showed significant resistance to spinosad, with resistance ratios between 16‐ and 37‐fold, compared with a susceptible laboratory colony. In contrast, only one population (Se‐Lazareto) showed significant resistance to methoxyfenozide (13‐fold).

CONCLUSION: Resistance management programmes should be established, particularly in areas where S. exigua has developed resistance to spinosad. Copyright © 2008 Society of Chemical Industry
Internal quantum efficiency behavior of a‐plane and c‐plane InGaN/GaN multiple quantum well with different indium compositions
Authors: Wang Te‐Chung , Ko Tsung‐Shine , Lu Tien‐Chang , Kuo Hao‐Chung , Gao Run‐Ci , Tsay Jenq‐Dar , Wang Sing‐Chung
Published: April 2008

We had investigated the potential of non‐polar a‐plane InGaN/GaN multiple quantum well (MQW) for high indium content blue/green emission. By comparisons of a‐plane and c‐plane MQW with different indium compositions, we concluded that without piezoelectric field, high indium content non‐polar a‐plane InGaN/GaN MQW is suitable for green light emitting diode (LED). Furthermore, similar to c‐plane GaN InGaN/GaN MQW, the localized state might enhance the performance of a‐plane MQW while the indium composition about 24% although the threading dislocation density (TDD) is quite high. On the other hand, the indium phase separation might also occur on a ‐plane InGaN/GaN MQW while the indium composition about 30% so that the photoluminescence intensity of the sample 810 °C low down and spectrum bandwidth broaden. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron stabilized ferromagnetism in GaGdN
Authors: Roever M. , Mai D.‐D. , Bedoya‐Pinto A. , Malindretos J. , Rizzi A.
Published: April 2008

With the aim of understanding the observed roomtemperature giant magnetic moment of highly diluted GaGdN reported in literature GaGdN, GaGdN:Si and GaGdN:H have been grown by molecular beam epitaxy (MBE) and the Gd concentration is between 1016 and 1021 cm3. All samples are ferromagnetic at 300 K as measured by SQUID and the very high saturation magnetic moment in this type of samples is confirmed by our experiments.

With co‐doping of hydrogen or silicon we were able to decrease or increase the strength of the magnetic moments in the layers, respectively. All our findings indicate that ferromagnetism is stabilized by electrons. Electrical measurements on GaGdN layers grown on highly resistive 6H‐SiC (0001) show a typical temperature dependence of hopping conductivity. The resistivity of the material is 0,1 to 13 kΩ cm in the temperature range from 60 to 10 K. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of high quality InN on production style PA‐MBE system
Authors: Gherasoiu I. , O'Steen M. , Bird T. , Gotthold D. , Chandolu A. , Song D. Y. , Xu S. X. , Holtz M. , Nikishin S. A. , Schaff W. J.
Published: April 2008

We have demonstrated step‐flow growth mode of InN, with monolayer height terrace steps (0.281 nm), using a production‐style PA‐MBE system, GEN200®. The surface morphology exhibits the step‐flow features on relatively large areas and the RMS roughness over an area of 5 × 5 μm2 is 1.4 nm. We also investigated the consequences of In droplets formation during the growth and we have found that the vapor‐liquid‐solid growth mechanism generates defective layer areas underneath droplets that have been formed early in the growth process. The Hall mobility of 1µm thick InN layers, grown in such step‐flow mode is slightly higher than 1400 cm2/Vs while for other growth conditions we have obtained mobility as high as 1904 cm2/Vs at room temperature. The samples exhibit high intensity photoluminescence spectra with a band edge that shifts with free‐carrier concentration. For the lowest carrier concentration of 5.6 × 1017 cm‐3 we observe PL emission at ∼0.64 eV. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Improved performance of GaInN based deep green light emitting diodes through V‐defect reduction
Authors: Detchprohm T. , Zhu M. , Xia Y. , Li Y. , Zhao W. , Senawiratne J. , Wetzel C.
Published: April 2008

The strong correlation between V‐defect density in the active region and light output power of GaInN based green and deep green light emitting diodes (LEDs) has been evaluated. The formation of such defects is confirmed as the major cause for rough growth morphology, drift of well and barrier widths, emission linewidth broadening, large color shift with current density, and thus poor light emission performance. We have optimized the epitaxial processes for the active region and successfully eliminated such defects from the entire device structure. The electroluminescence intensities from these V‐defect‐free devices with dominant wavelengths ranging from 520 to 570 nm, improve by a factor of two under high injection current density up to 100 A/cm2. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Assessment of scanning spreading resistance microscopy for application to n‐type GaN
Authors: Sumner J. , Oliver R. A. , Kappers M. J. , Humphreys C. J.
Published: April 2008

This paper investigates the behaviour of scanning spreading resistance microscopy (SSRM) when applied to GaN. To this end, appropriate Si‐doped multilayers were grown to test SSRM's carrier concentration sensitivity and it was found that, for samples with no undoped regions, layers with dopant concentrations ranging from 1×1019 cm–3 to 2.5×1018 cm–3 could be distinguished. However we have noted that the relationship between SSRM signal, applied bias and dopant level is complex and that further work is needed before quantification of unknown samples can be attempted. Furthermore, in samples with undoped layers, it is very difficult to obtain any SSRM signal. In terms of recommended operating parameters, it was found that SSRM only usefully distinguished between dopant layers for applied DC biases in the range of ∼2 ‐ 7 V. Above this voltage damage to the sample occurs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chemical lift‐off of GaN epitaxial films grown on c‐sapphire substrates with CrN buffer layers
Authors: Goto H. , Lee S. W. , Lee H. J. , Lee Hyo‐Jong , Ha J. S. , Cho M. W. , Yao T.
Published: April 2008

GaN epitaxial films are grown on c‐plane sapphire substrates with CrN buffer. The GaN layers show high crystalline quality and smooth surface morphology without being cracked. Selective etching of CrN buffer is performed by wet etching using conventional Cr metal etchant, which results in success ful lift‐off of GaN thick layers. We confirm that the crystalline quality of GaN does not change through the etching process. These results indicate that the chemical lift‐off process using CrN buffer is promising for production of both freestanding GaN substrates and vertical‐structure devices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Palladium‐based on‐wafer electroluminescence studies of GaN‐based LED structures
Authors: Salcianu C. O. , Thrush E. J. , Plumb R. G. , Boyd A. R. , Rockenfeller O. , Schmitz D. , Heuken M. , Humphreys C. J.
Published: April 2008

Electroluminescence (EL) testing of Light Emitting Diode (LED) structures is usually done at the chip level. Assessing the optical and electrical properties of LED structures at the wafer scale prior to their processing would improve the cost effectiveness of producing LED‐lamps. A non‐destructive method for studying the luminescence properties of the structure at the wafer‐scale is photoluminescence (PL). However, the relationship between the on‐wafer PL data and the final device EL can be less than straightforward (Y. H Aliyu et al., Meas. Sci. Technol. 8, 437 (1997) [1]) as the two techniques employ different carrier injection mechanisms. This paper provides an overview of some different techniques in which palladium is used as a contact in order to obtain on‐wafer electroluminescence information which could be used to screen wafers prior to processing into final devices. Quick mapping of the electrical and optical characteristics was performed using either palladium needle electrodes directly, or using the latter in conjunction with evaporated palladium contacts to inject both electrons and holes into the active region via the p‐type capping layer of the structure. For comparison, indium was also used to make contact to the n‐layer so that electrons could be directly injected into that layer. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
EpiEL provides advanced optical characterization for nitride LED epi‐wafers
Authors: Ma Max Xianyun , Jia Helen Jinghong
Published: April 2008

A virtual LED device fabrication and characterization technology, called EpiEL, has been developed to non‐destructively measure LED device parameters directly on LED epiwafers. As through a finished device, the system reveals not only the electro‐luminescence (EL) but also the electrical properties of the material. The developed EpiEL mapping system can rapidly obtain EL spectrum, LIV, output characteristics, wavelength & FWHM shift curves, as well as wafer‐level uniformity about slope quantum efficiency, emission intensity, peak/dominant wavelength, FWHM, driving voltage/current, etc.. EL measurement is usually performed on finished device (such as LED) since it needs a device structure to inject current. EpiEL mapping system overcomes this limitation by instantly forming a well‐defined LED device inside the material. With such capability, EpiEL technology provides a unique electroluminescence solution for optoelectronic (especially emerging solid‐state lighting) industry which brings better capability and efficiencies: instant feedback for material development and device‐level quality control right after material growth. Recent investigation indicated that most of current nitride‐based LED epiwafers have a non‐uniform material structure which leads to different optical observations at epitaxial and substrate sides. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminescence properties of GaPN layer grown by OMVPE
Authors: Hatakenaka S. , Wakahara A. , Nakanishi Y. , Furukawa Y. , Okada H. , Yonezu H.
Published: April 2008

The effect of carbon incorporation on luminescence properties of GaPN grown by organometallic vapor phase epitaxy (OMVPE) has been investigated. Trimethylgallium (TMGa) and trimethylgallium (TEGa) were used as Ga precursors. The carbon concentration of 1.1×1017cm–3 was obtained by using TEGa, whereas that of GaPN grown using TMGa was 4.0×1017cm–3. Non‐radiative recombination rate was also reduced to about 1/100 by using TEGa. Moreover, the spatial fluctuation of N content and Non‐radiative rate was reduced with increasing substrate temperature. Therefore, luminescence properties of GaPN could be improved by using TEGa at high substrate temperature. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mechanisms of AlInN growth by MOVPE: modeling and experimental study
Authors: Yakovlev E. V. , Lobanova A. V. , Talalaev R. A. , Watson I. M. , Lorenz K. , Alves E.
Published: April 2008

Factors affecting the AlInN layer composition have been studied, using both modelling and experimental approaches. The experiments have been performed in a single‐wafer Aixtron AIX 200/4 RF‐S reactor at setpoint temperatures ranging from 760 to 840 °C, which corresponds to the InN content variation in a wide interval from 13 to about 24%, if other process parameters remain unchanged. The computations fit well the compositional experimental data, and can be used to identify the mechanisms governing the incorporation of the indium atoms into MOVPE grown AlInN layers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In‐situ measurement of the strain relaxation of GaN nanograins during X‐ray irradiation
Authors: Choe Hyeokmin , Lee Sanghwa , Sohn Yuri , Kim Chinkyo
Published: April 2008

GaN nanograins were grown on a c‐plane sapphire substrate and their strain relaxation due to x‐ray irradiation was investigated in‐situ by utilizing synchrotron xray scattering. The GaN nanograins were constantly exposed to the synchrotron X‐ray and θ ‐2θ scans through the (002) Bragg peak of GaN were repeatedly carried out during the irradiation.

The Bragg peak of the compressively strained GaN nanograins gradually shifted toward higher angle, which implies that the GaN nanograins in compressive strain experienced strain relaxation during x‐ray irradiation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
RF‐MBE growth of cubic InN films on YSZ(001) vicinal substrates
Authors: Nakamura T. , Kataoka T. , Katayama R. , Yamamoto T. , Onabe K.
Published: April 2008

Cubic InN (zincblende structure) films have been directly grown on yttria‐stabilized zirconia (YSZ) (001)‐oriented and vicinal substrates by rf‐plasma‐assisted molecular beam epitaxy (RF‐MBE) (The vicinal substrates are misoriented by 1° toward 〈110〉.), and structurally characterized by X‐ray diffraction and atomic force microscopy. Compared with the growth on the (001)‐oriented substrate, the surface grain size of the cubic InN film is remarkably large for the growth on the vicinal substrates. From the 2θ/ω and ω X‐ray reciprocal space mapping measurements, hexagonal InN is found to be preferentially generated on the c‐InN{111} facets. By using the YSZ(001) vicinal substrate, the hexagonal phase incorporation ratio decreased from 16.3% on the (001)‐oriented substrate to 11.7% with the same growth condition. And on the vicinal substrate, hexagonal InN is generated predominantly from the c‐InN(111) facets which are inclined to the upward direction of the atomic steps. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
InGaN compositional patterning by ultraviolet photoexcitation during NH3‐based MOMBE – A pathway to 3D epitaxy
Authors: Pritchett D. , Henderson W. , Billingsley D. , Doolittle W. A.
Published: April 2008

Lateral compositional patterning of InGaN during NH3‐based MOMBE by digital micromirror patterning of UV photoexcitation is demonstrated. Preferential desorption of In/In‐methyl species during InGaN surface exposure to an elliptically focused 5 kW Hg‐Xe arc lamp (λ = 365 nm) limits the incorporation of indium during growth. Localized photoexcitation results in the preferential In/In‐methyl desorption, resulting in indium mole fractions of 0.10 in unexposed regions to as low as 0 in fully exposed regions. The technique demonstrates promise for integration of micromirrors for dynamic and maskless selective epitaxy towards the realization of complex, 3D device structures. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)