bluuebunny/crossref_metadata_2025 huggingface dataset:
cAMP‐Induced Expression of the Orphan Nuclear Receptor Nur77 in MA‐10 Leydig Cells Involves a CaMKI Pathway
Authors: Martin Luc J. , Boucher Nicolas , El‐Asmar Bassam , Tremblay Jacques J.
Published: February 2009

ABSTRACT: The Nur77 (Nr4a1) gene, encoding the orphan nuclear receptor NUR77 (NR4A1), is an immediate early response gene whose expression is rapidly induced by a variety of physiologic stimuli. Nur77 is expressed in several organs, including the classic steroidogenic tissues: gonads and adrenal. In MA‐10 Leydig cells, NUR77 has been shown to regulate expression of several genes involved in steroidogenesis and male sex differentiation. In Leydig cells, androgen biosynthesis is controlled primarily by the pituitary gonadotropin luteinizing hormone (LH) acting via its receptor (LH‐R), which in turn activates the adenylate cyclase/cyclic adenosine monophosphate (cAMP) signaling pathway. Even though Nur77 expression is induced both at the mRNA and protein levels in response to LH/forskolin/cAMP in Leydig cells, the mechanisms involved remain largely unknown. Here, we report that cAMP‐mediated induction of Nur77 expression at the protein, mRNA, and promoter levels in MA‐10 cells involves different mechanisms. We found that increased NUR77 protein requires transcription and translation, whereas increased Nur77 mRNA does not require de novo protein synthesis, and would therefore rely on transcription factors already present in the cell. In addition, our detailed analysis of the Nur77 promoter in MA‐10 cells revealed that distinct regulatory elements are involved in basal and cAMP‐induced Nur77 transcription. Finally, we found that maximal cAMP‐mediated increase in Nur77 promoter activity involves a Ca2+/calmodulin kinase (CaMK)‐dependent pathway and that Ca2+/calmodulin kinase I regulates Nur77 promoter activity in Leydig cells. Thus, our findings demonstrate the involvement of various mechanisms in the regulation of Nur77 expression in MA‐10 Leydig cells, including a previously uncharacterized CaMK pathway.
Dynamics of Social Capital and Their Performance Implications: Lessons from Biotechnology Start-ups
Authors: Maurer Indre , Ebers Mark
Published: February 2009

Based on comparative longitudinal case analyses of six new biotechnology firms, this paper explores how the configuration, management, and evolution of entrepreneurial firms' social capital affect firm performance. Findings suggest that firms can realize performance benefits when their members repeatedly adapt the configuration of their social capital to changing resource needs, while inertia turns a firm's social capital into a liability. Our research provides a dynamic view of the conditions and processes that produce such inertia, allow firms to overcome it, and develop a firm's social capital to organizational advantage. A core theoretical contribution of our study is to identify and theorize how the internal organization of firms' management of relationships with external partners, through horizontal and vertical differentiation and integration, affects the dynamic of firms' social capital, adaptive capacity, and performance.
Ascending Auctions with Package Bidding
Authors: Ausubel Lawrence M , Milgrom Paul R
Published: February 2009

A family of ascending package auction models is introduced in which bidders may determine their own packages on which to bid. In the proxy auction (revelation game) versions, the outcome is a point in the core of the exchange economy for the reported preferences. When payoffs are linear in money and goods are substitutes, sincere reporting constitutes a Nash equilibrium and the outcome coincides with the Vickrey auction outcome. Even when goods are not substitutes, ascending proxy auction equilibria lie in the core with respect to the true preferences. Compared to the Vickrey auction, the proxy auctions generate higher equilibrium revenues, are less vulnerable to shill bidding and collusion, can handle budget constraints much more robustly, and may provide better ex ante investment incentives.
Automatic calibration of a scanner-based laser welding system
Authors: Stache Nicolaj C. , Stollenwerk André , Gedicke Jens , Olowinsky Alexander , Knepper Achim , Aach Til
Published: February 2009

In precision engineering scanners are widely used for laser beam positioning. Equipped with cameras, scanners enable process monitoring or even position recognition of the parts to be welded. To allow precise welding or position recognition, it is essential to calibrate a welding system. Instead of calibrating the whole system, most approaches only help to adjust the laser beam position. Consequently, the varying lateral offset between the laser’s focus point and the camera’s field of view, due to chromatic aberration of the scanner optics, cannot be compensated. Furthermore, these approaches require manual microscopic measurement of weld seams, which comes along with several downsides. This paper proposes two techniques for automatic calibration without these downsides by use of the system-incorporated camera. The first technique is the calibration at laser wavelength. To this end, the system automatically creates laser spots, evaluates their positions and possible offsets, and finally fits an affine model for compensation. The second technique is based on a specially coded test pattern, which is used for calibration at camera wavelengths. Experimental results confirm the accuracy of the calibration obtained.
Laser flash photolysis of diazo-2, a caged calcium chelator: The relationship between the extent and rate of smooth muscle relaxation
Authors: Pelc R. , Ishii N. , Ashley C. C.
Published: February 2009

Relaxations brought about by laser flash photolysis of diazo-2, a caged calcium chelator, were recorded in the anterior byssus retractor muscle (ABRM) of Mytilus edulis (a molluscan “catch” muscle). The relaxation rate was characterized by half-time (T1/2) and one-fifth-time (T1/5). We show that, unlike, e.g., in the mammalian cardiac muscle, the relaxation rate increases with the extent of relaxation (the latter being expressed as a percentage of an immediately preceding activation by Ca2+), in a manner similar to the Ca2+ activation process, as shown in other muscles [Lea and Ashley, J. Physiol. (Lond.) 427, 435–453 (1990); Saeki et al., J. Mol. Cell. Cardiol. 36, 371–380 (2004)]. This increase (i.e., decrease in T1/2 and T1/5) levels off at extent of relaxation ≃50%. The present paper highlights the need to take into account the differences in the extent of smooth muscle (especially the catch or “latch” type) relaxation. The data may be used in modeling the mechanism underlying the calcium-dependent (phasic) smooth muscle relaxations.
Local susceptibility of the retina, formation and duration of afterimages in the case of Class 1 laser products, and disability glare arising from high-brightness light emitting diodes
Authors: Reidenbach Hans-Dieter
Published: February 2009

According to the new European Directive on Artificial Optical Radiation, the employer has to determine the exposure and the assessment of risks and in addition, he shall give particular attention to any indirect effects, such as temporary blinding, when carrying out the risk assessment. Up to now, secondary effects such as temporary blinding have not been regarded in safety standards and there exist but a few data on this topic as far as modern artificial high-brightness (HB) light sources are concerned. Temporary blinding from a Class 1 laser and a white high-brightness light emitting diode (LED) in the visual field has been investigated as a function of the glare angle and of the amount of the emitted optical energy. In an extensive study with a He-Ne laser at a wavelength of 632.8 nm, it was found that even for output powers of 5 to 30 μW, the tested subjects reported intense glare effects and felt uncomfortable due to the high brightness. The durations of afterimages ranged up to 300 s and have been measured as a function of the angle between the line of sight and the laser beam direction for an exposure duration up to 10 s. The maximum afterimage duration was found for the foveal pit. In the case of a HB-LED, the investigated power level was between 0.0045 and 3.96 mW measured in a 7 mm aperture, and the exposure durations were limited to 20 s. The annoyance duration, i.e., the capability to read after an irradiation, was between about 10 and 25 s and relatively independent of the applied power, but interindividually different. As a result of the investigations instructions for users of Class 1 lasers and HB-LEDs should be given in order to take into account temporary impairment of visual tasks due to dazzling and glare effects which are accompanied with relatively long lasting afterimages.
Orbicular granite near Jelenia Góra in southwestern Poland: the first outcrops?
Authors: Kennan Pádhraig , Lorenc Marek
Published: February 2009

Orbicular granite near Jelenia Góra in southwestern Poland: the first outcrops?

In 1802, Leopold von Buch described some outcrops of orbicular granite in the Karkonosze granite, Lower Silesia, Poland. In that publication, Abraham Gottlieb Werner wrote a foreword dated 1800. The Silesian discovery predates that of the well-known orbicular diorite (Napoleonite) in outcrop on Corsica and, thus, may be the first ever record of this distinctive rock type in its geological context. The characterizing, closely-packed, simple orbs comprise K-feldspar cores surrounded by rims of radiating K-feldspar and quartz. Rapid growth from a hydrous, pegmatitic melt is indicated. The Karkonosze outcrop, in the timing of its discovery, is a unique part of the geological heritage.
Understanding the Professional Socialization of Canadian Physical Therapy Students: A Qualitative Investigation
Authors: Bartlett Doreen J. , Deborah Lucy S. , Bisbee Leslie , Conti-Becker Angela
Published: February 2009

Purpose: To understand the professional socialization of physical therapy (PT) students.

Method: Forty-two students enrolled in our newly developed master's degree programme wrote three-page reflective journals on a critical learning incident after each of three selected clinical experiences. The journals were coded and analyzed, and major themes were identified and described. A separate cohort of 44 students participated in focus groups after the same three clinical experiences to check the trustworthiness of the results.

Results: Following the first placement, the main themes coded were emotions, self-confidence, professionalism in the real world, communication, and learning by doing. After the intermediate placement, major themes were idealism versus realism, depth of communication with clients, and breadth of communication with family members and colleagues. Aspects of clinical learning were variable, and self-confidence remained an issue. After the final placement, most students were deeply engaged with their clients and self-confidence had developed to the point of self-efficacy. Tensions increased between the concept of ideal practice and the pragmatics of actual practice, and the concept of self as protégé (rather than as object of the supervisor's evaluation) emerged. The themes were subsequently assembled in a booklet with representative quotations.

Conclusion: These results contribute to foundational knowledge required by PT educators, including clinical instructors, by explicitly describing the professional socialization of PT students.
Management of Fall-Related Injuries in the Elderly: A Retrospective Chart Review of Patients Presenting to the Emergency Department of a Community-Based Teaching Hospital
Authors: Miller Erin , Wightman Elizabeth , Rumbolt Karla , McConnell Sara , Berg Katherine , Devereaux Moira , Campbell Fiona
Published: February 2009

Purpose: To identify current practice for elderly individuals who have sustained a fall-related injury and subsequently presented to the emergency department (ED) of a community-based hospital in Toronto, Ontario.

Methods: A retrospective longitudinal chart review was conducted for 300 persons, 65 years of age and older, who presented to the ED of a community-based teaching hospital with a fall from June 2004 through May 2005. Data were collected using a tool created by the investigators (based on information gathered through a literature review) to capture information related to risk factors for falling.

Results: Our study sample was demographically similar to elderly individuals in other fall-related studies. Most patients discharged directly from the ED did not receive multidisciplinary care. In the ED, all patients saw a nurse or physician, while only 1.3% (n = 4) saw a physical therapist, 3.0% (n = 9) saw an occupational therapist, and 5.3% (n = 16) saw a social worker. At discharge, 62% (n = 152) had no documented referral for follow-up care. Abilities related to falls in elderly individuals were not consistently assessed in the ED. Frequency of assessment for these abilities was as follows: (1) gait, 10.2%; (2) balance, 4.1%; (3) lower-extremity range of motion, 4.9%; (4) lower-extremity strength, 2.0%; (5) cognition, 26.1%; (6) vision, 2.0%; (7) ability to perform activities of daily living, 7.3%. In the 6 months following the index fall, 8.3% of patients returned to the ED of the same hospital because of a subsequent fall.

Conclusions: In the ED, fall-related risk factors were not consistently assessed or documented, and few patients received multidisciplinary management. Since elderly individuals who fall commonly present to the ED, the implementation of evidence-based strategies aimed at preventing repeat falls should be considered.
Relationship between Preoperative Patient Characteristics and Expectations in Candidates for Total Knee Arthroplasty
Authors: Razmjou Helen , Finkelstein Joel A. , Yee Albert , Holtby Richard , Vidmar Marjan , Ford Michael
Published: February 2009

Purpose: The purpose of this study was to determine the relationship between patient expectations for improvement following primary total knee arthroplasty (TKA) and patient preoperative characteristics.

Methods: This was a cross-sectional analysis of preoperative expectations. Expectations for improvement were evaluated in six distinct domains. The baseline factors used as independent variables were age, gender, presence of comorbidity, sub-domains of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC; pain, stiffness, physical limitation related to lower extremity), and SF-36 physical and mental health component scores. Stepwise logistic regression analysis was applied to examine the relationships between dependent and independent variables.

Results: The study cohort consisted of 236 candidates for TKA (154 women and 82 men, mean age 67, SD = 9.98). Expectations were high on average. Presence of comorbidity was associated with expectations of pain relief. Preoperative mental health was related to expectations for a return to activities of daily living; age, gender, physical health, and mental health were related to expectations for improved leisure, recreational, and sports activities. Preoperative physical health was related to expectations for potential return to full recovery. No baseline factors were associated with expectations for improved range of motion or for providing care to and interacting with others.

Conclusion: Expectations related to recovery from surgery appeared to have distinct dimensions and were associated with patient baseline characteristics.
Prediction of thermodynamic activities in binary iron-based alloys using two-point Padé approximants
Authors: Stella Eduardo , Stella Jorge
Published: February 2009

A method for predicting activities as a function of the concentration in liquid solutions for binary FeCo, FeCu, FeNi, FeMn and FePd systems using Padé approximants is presented. Padé approximants of orders 4/0 and 1/3 are proposed for the model using as input variables only the conditions from Henry's law at a given temperature. Results derived from the approximant 4/0 show good agreement with the experimental data in systems with moderate positive and negative deviations from the Raoultian behaviour. On the other hand, the approximant 1/3 shows a satisfactory agreement in the FeCu system which exhibits a high positive deviation from the Raoultian behaviour. A comparison with the results from a Redlich – Kister expansion using the same input conditions is discussed.
Determination of the concentration dependent diffusion coefficient of nitrogen in expanded austenite
Authors: Christiansen Thomas L. , Somers Marcel A. J.
Published: February 2009

The concentration dependent diffusion coefficient of nitrogen in expanded austenite was determined from the rate of retracting nitrogen from thin initially N-saturated coupons. Nitrogen saturated homogeneous foils of expanded austenite were obtained by nitriding AISI 304 and AISI 316 in pure ammonia at 693 K and 718 K. Denitriding experiments were performed by equilibrating the foils with a successively lower nitrogen activity, as imposed by a gas mixture of ammonia and hydrogen. The concentration depen-dent diffusion coefficient of nitrogen in expanded austenite was approximated in the composition range where nitrogen can be extracted by hydrogen gas at the diffusion temperature. Numerical simulation of the denitriding experiments shows that the thus determined concentration dependent diffusion coefficients are an accurate approximation of the actual diffusivity of nitrogen in expanded austenite.
Deformation and fracture of Ti-base nanostructured composite
Authors: Das Jayanta , Buem Kim Ki , Zhang Zhe-Feng , He Guo , Müller Clemens , Eckert Jürgen
Published: February 2009

The in-situ formation of nano-eutectic/primary dendrite bulk composites in Ti-base multicomponent alloy systems allows the design of advanced high strength materials, where a nanostructured matrix is combined with ductile β-Ti solid solution dendrites as a toughening phase. This microstructure can be achieved over a wide range of cooling rates. The multicomponent recipe stabilizes the β-Ti phase and helps to reduce the eutectic spacing to the nanometer scale. The superiority in the mechanical properties, i. e. high room temperature ductility (up to 30 %) as well as high strength (up to 2600 MPa), stems from the possibility to tailor the alloy composition leading to the formation of different volume fractions of dendrites in a nanostructured eutectic matrix. All composites with high volume fraction of dendrites offer a high ductility (∊p = 8 – 30 %) and a final failure angle in the range of 46 – 51°. The role of the volume fraction of the dendrites in the composite in enhancing the ductility as well as the fracture angle is critically assessed. The deformation and fracture mechanisms are linked to the macroscopic fracture features as well as to impingement of the shear bands leading to rotation of the shear plane and lattice distortion at the atomic level.
X-ray analysis of steep residual stress gradients: The 2θ-derivative method
Authors: Erbacher Thomas , Wanner Alexander
Published: February 2009

Machined ceramics and other hard materials exhibit very steep subsurface gradients of residual stresses. X-ray analysis enables the non-destructive assessment of the distributions of these residual stresses versus the distance from the surface via variation of the penetration depth of the X-rays. Conventional evaluation procedures are based on continuous or piecewise defined polynomial functions of stress versus distance, which are fitted to the X-ray data by means of complex solution schemes. These solution schemes are, however, in many cases unstable and difficult to handle. We have developed an entirely novel evaluation procedure which is based on polynomials fitted to the “2θ vs. sin2 ψ” plots obtained from the X-ray measurements. It is shown that the residual stress profiles can be computed explicitly from these polynomials without any further assumptions. The evaluation procedure is described in detail and demonstrated in a case study on ground alumina ceramics.
Unconstrained solidification and characterisation of near-eutectic Al–Cu–Ag alloys
Authors: Ebzeeva S. , Nagels E. , Froyen L.
Published: February 2009

This study focuses on the microstructure formation in two Al – Cu – Ag alloys with near-eutectic composition on either side of the α(Al)/θ-Al2Cu groove. The alloys solidified equiaxially with two different cooling rates for each composition of alloy. The primary phases formed are α(Al) or θ-Al2Cu, but univariant and invariant eutectic reactions are common. In hypoeutectic samples macrosegregation of the α(Al) phase occurred. The univariant α(Al)/θ-Al2Cu eutectic in these samples is formed by coupled two-phase structures. The univariant eutectic in the samples, which exhibit primary θ-Al2Cu, grew partially competitively due to the α(Al) single phase instability.

It is suggested that the difference in solubility of the segregating element Ag in α(Al) and θ-Al2Cu phases and processing parameters such as cooling rates determine the resulting microstructure.
Microstructural control of FeB-inoculated mottled low-alloy white iron by a design of experiments approach
Authors: Asensio Juan , Álvarez José F. , Vander Voort George F.
Published: February 2009

The present research identifies manufacturing factors that influence the metastable constituent in mottled Nihard cast irons. These irons constitute the roll shells of duplex work rolls processed by centrifugal casting. The research methodology employed a saturated design of experiments program with 7 factors, 8 experiments and a resolution of III. An increase from 6 to 10 kg/T of inoculated FeB enhanced metastable solidification by increasing the amount of ledeburite and the amount of cementite. Similarly, decreasing the Si content from 1.1 – 1.2 to 0.9 – 1.0 wt.% increased the amount of ledeburite and cementite. Finally, the use of casting machines without isolating sleeves increased the roll barrel hardness in the as-cast condition and after tempering.
Dislocation structure and crystallite size distribution in lath martensite determined by X-ray diffraction peak profile analysis
Authors: Nedjad S. Hossein , Gharabagh M.-R. Movaghar
Published: February 2009

X-ray diffraction peak profiles obtained from 18Ni lath martensite were analyzed in accordance with the modified Williamson – Hall and modified Warren – Averbach methodologies, aided by supplemental optical and transmission electron microscopy. After instrumental broadening removal, structural peak broadenings were determined for diffraction lines. Consequently, a log-normal size distribution with a mean size of about 156 nm was determined, corresponding reasonably to the lath width illustrated by means of transmission electron microscopy. Further, a dislocation density of 0.723 × 1016 m– 2 along with a near equal proportion of edge and screw dislocations were identified. Determination of the dislocation arrangement parameter revealed a weak dipole and thus, weak screening action of dislocation strain fields.
Effect of minor addition of Pb upon interfacial reactions and mechanical properties at Sn-3.0Ag-0.5Cu/Cu and Sn-58Bi/Cu solder joints
Authors: Yen Yee-Wen , Chou Weng-Ting , Chen Hong-Chih , Liou Wei-Kai , Lee Chiapyng
Published: February 2009

Interfacial reactions and mechanical properties between the Cu and Pb-free solders, Sn-3.0Ag-0.5Cu and Sn-58Bi with addition of 0.1 to 1.0 wt.% Pb are investigated in this study. Two kinds of intermetallic compounds, scallop-shaped Cu6Sn5 and plane layered Cu3Sn phases, were found in both Sn-3.0Ag-0.5Cu + Pb/Cu and Sn-58Bi + Pb/Cu couples. The intermetallic compound thickness increased with longer reaction times, higher reaction temperatures and greater Pb contents. The Cu6Sn5 phase was the thicker intermetallic compound in the Sn-3.0Ag-0.5Cu + Pb/Cu couple. However, in the Sn-58Bi + Pb/Cu system, the Cu3Sn phase is the thicker intermetallic compound. Experimental results indicate that the higher Pb concentration in Sn-3.0Ag-0.5Cu or Sn-58Bi solders reduces the alloy liquidus temperature and increases the thickness of the intermetallic compound. Thicker intermetallic compounds reduce the mechanical strength of the solder joint.
The influence of microstructural characteristics and contaminants on the mechanical properties and fracture topography of low cost Ti6Al4V alloy
Authors: Bozic Dusan , Sekulic Danijela , Stasic Jelena , Rajkovic Viseslava , Jovanovic Milan T.
Published: February 2009

Low cost titanium alloy compacts were produced via the powder metallurgy approach through the hydride – dehydride process and hot consolidation (hot pressing and hot isostatic pressing). The conditions of the reversible hydride – dehydride process were determined by X-ray and scanning electron microscopy characterisation of powders. Powders were consolidated both above and below the β transformation temperature. The morphology of the microstructure, and the presence of open and closed pores, as well as residual particles of hydrides and oxides have a direct influence on the mechanical properties of compacts (tensile properties and impact toughness).
The effect of alloying elements on constrained carbon equilibrium due to a quench and partition process
Authors: de Avillez Roberto R. , da Costa e Silva André Luiz V. , Martins Ana Rosa F. A. , Assunção Fernando C. Rizzo
Published: February 2009

The model proposed by Speer et al. to calculate the constrained carbon equilibrium is expanded to include any number of substitutional solutes and coded with the MatLab and Thermo-Calc programs. This model is used to evaluate the effect of Al, Cr, Cu, Mn, Mo, Ni and Si solutes on the final austenite carbon concentration of ternary Fe – X – C alloys. Comparison is also made with the carbon concentration measured experimentally in some Transformation Induced Plasticity steels.
A new kinetic treatment of the oxidation of β-SiAlON powder
Authors: Hou Xinmei , Liu Xiaodan , Guo Min , Chou Kuochih
Published: February 2009

The oxidation kinetics of β-SiA10N (Si3Al3O3N5) powder prepared by reaction sintering have been investigated from both experimental and theoretical aspects. In the oxidation experiments, X-ray diffraction, optical microscopy and thermogravimetry were used to study the oxidation mechanism and kinetics of β-SiAlON powder. Based on the ex-perimental data, a new model for predicting the oxidation process of β-SiAlON powder has been developed, which offers an analytic form expressing the oxidation mass change as a function of time and temperature. The effect of particle size distribution on oxidation has especially been discussed. The new model was used to predict the oxidation behavior of β-SiAlON powder and the calculated results agreed well with the experimental data with the activation energy to be 253 kJ · mol−1.
The combined effect of titanic carbide and aluminum phosphide on the refinement of primary silicon in Al-50Si alloy
Authors: Dai Hongshang , Liu Xiangfa
Published: February 2009

Two refinement methods for Al-50Si alloy are presented in this article: one way is using a newly developed Si-20P alloy at 1573 K; another technique is using the Si-20P alloy in company with Al-TiO2-C mixture powder at 1473 K. Compared to the first method, the second one not only has better refinement effect on primary Si but also lower refinement temperature. These results are due to the combined effect of TiC and AlP on the refinement process, and the duplex TiC/AlP nucleus of primary silicon has been demonstrated using electron probe micro-analysis. Moreover, the reaction of Al-TiO2-C mixture powder with increasing temperature was investigated using differential scanning calorimetry, which shows that the TiC particles are produced at about 1473 K. AlP particles combine with the in-situ TiC particles in the melt, which is the main reason for the formation of a duplex nucleus, and the disregistry between TiC and AlP in low-index planes is also discussed.
Experimental survey on fluid brazing in ancient goldsmith' art
Authors: Cagnetti Andrea
Published: February 2009

The paper tries to show the essential role played by a brazing process in the manufacturing of filigree and granulation decorated ancient jewels. A purely experimental framework is proposed. Reasons for such a methodological choice are outlined and general protocols for a standard experiment are provided. Specific advantages for the accomplishment of the manufacturing process in all its stages are shown to be related to the employment of a fluid brazing solution. The concordance of the few available ancient sources, the simplicity of technique's application, as well as the jewels concretely produced during years of research in the field, highlight the plausibility of the adopted approach.
Effect of electropulsing on the tensile flow stress of ultrafine-grained 3Y-TZP at 1400°C
Authors: Yang Di , Conrad Hans
Published: February 2009

Short DC pulses (∼10– 4s duration with a maximum electric field strength of 2.0 – 9.3 kV cm– 1) applied continuously at a frequency of 10 Hz reduced the tensile flow stress of ultrafine-grained 3Y-TZP at 1400 °C. The decrease in flow stress was attributed to a retardation of dynamic grain growth by the average electric field. The degree of retardation decreased with strain, which correlated with the calculated reduction in electric field strength due to the change in dimensions of the specimen as it elongates. Considering the present electropulsing results along with those obtained previously employing DC and 60 Hz AC fields, it was found that the ratio of the decrease in grain size with field to the grain size without field, was proportional to the average effective electric field strength, relatively independent of test temperature in the range of 1400 – 1500 °C. The proportionality constant increased in the order DC, AC, EP, indicating that a varying field has a greater effect on retarding dynamic grain growth than a constant DC field.
Improving Flow Balance during Filling a Multi-cavity Mold with Modified Runner Systems
Authors: Huang T.-C. , Huang P.-H. , Yang S.-Y. , Ko T.-Y.
Published: February 2009

Multi-cavity injection molding has been regarded as low cost mass-production method for producing plastic products such as optical elements. However, the flow imbalance during filling a multi-cavity mold using symmetrical runner system is a serious problem. This paper is devoted to improving the flow balance by modifying the runner system design. For this purpose, four eight-cavity molds with four modified symmetrical runner systems are designed, constructed and tested. They are tapering H-type runners, pinned H-type runners, curved A runners, and curved B runners. The flow imbalance in each runner system is observed and measured with the aid of short-shot experiments.

The experimental results indicate that the tapering H-type runner system can improve flow balance. The pinned H-type runner system fails to improve flow balance. The curved A and B runner system can reverse the imbalance trend, but the stability of the curved systems is poor at high melt temperature.
Evaluation of Various Metallic Coatings on Steel to Mitigate Biofilm Formation
Authors: Kanematsu Hideyuki , Ikigai Hajime , Yoshitake Michiko
Published: February 2009

In marine environments and water systems, it is easy for many structures to form biofilms on their surfaces and to be deteriorated due to the corrosion caused by biofilm formation by bacteria. The authors have investigated the antibacterial effects of metallic elements in practical steels so far to solve food-related problems, using Escherichia coli and Staphylococcus aureus. However, from the viewpoint of material deterioration caused by bacteria and their antifouling measures, we should consider the biofilm behavior as aggregate rather than individual bacterium. Therefore, we picked up Pseudomonas aeruginosa and Pseudoalteromonas carageenovara in this study, since they easily form biofilms in estuarine and marine environments. We investigated what kind of metallic elements could inhibit the biofilm formation at first and then discussed how the thin films of those inhibitory elements on steels could affect biofilm formation. The information would lead to the establishment of effective antifouling measures against corrosion in estuarine and marine environments.
The relationship between European genetic admixture and body composition among Hispanics and Native Americans
Authors: Klimentidis Y.C. , Miller G.F. , Shriver M.D.
Published: February 2009

Previous studies have shown a relationship between health‐related phenotypes and the degree of African, European, or Native American genetic admixture, indicating that there may be a genetic component to these phenotypes. However, these relationships may be driven to a large extent by the environmental differences that co‐vary with admixture differences between and within groups. In this study, we examine the relationship between genetic admixture and two phenotypic measurements that are potentially related to health: body mass index (BMI) and percent body fat (PBF). In addition to admixture proportions, we attempt to assess the influence of some environmental covariates by examining how the phenotypes vary with self‐reported household income, education of parents, and physical activity level. Genetic, anthropometric, and environmental data were collected from 170 self‐reported Hispanic and Native American university students in Albuquerque, NM. We examine the relationships between genetic admixture, phenotype, and environment in both the full sample, as well as in Hispanics and Native Americans separately. Among Hispanics, we find no significant relationship between genetic admixture and body composition. Among Native Americans, despite a small sample size, we find a statistically significant, negative relationship between European genetic admixture and PBF and BMI, after adjusting for other predictor variables. We compare our findings to previous research, and discuss their implications for understanding health disparities within and between ethnic groups. Am. J. Hum. Biol. 2009. © 2009 Wiley‐Liss, Inc.
A novel chromosome 19p13.12 deletion in a child with multiple congenital anomalies
Authors: Jensen Daniel R. , Martin Donna M. , Gebarski Stephen , Sahoo Trilochan , Brundage Ellen K. , Chinault A. Craig , Otto Edgar A. , Chaki Moumita , Hildebrandt Friedhelm , Cheung Sau Wai , Lesperance Marci M.
Published: February 2009

We describe a patient with multiple congenital anomalies including deafness, lacrimal duct stenosis, strabismus, bilateral cervical sinuses, congenital cardiac defects, hypoplasia of the corpus callosum, and hypoplasia of the cerebellar vermis. Mutation analysis of EYA1, SIX1, and SIX5, genes that underlie otofaciocervical and/or branchio‐oto‐renal syndrome, was negative. Pathologic diagnosis of the excised cervical sinus tracts was revised on re‐examination to heterotopic salivary gland tissue. Using high resolution chromosomal microarray analysis, we identified a novel 2.52 Mb deletion at 19p13.12, which was confirmed by fluorescent in situ hybridization and demonstrated to be a de novo mutation by testing of the parents. Overall, deletions of chromosome 19p13 are rare. © 2009 Wiley‐Liss, Inc.
Mowat–Wilson syndrome: Facial phenotype changing with age: Study of 19 Italian patients and review of the literature
Authors: Garavelli L. , Zollino M. , Mainardi P. Cerruti , Gurrieri F. , Rivieri F. , Soli F. , Verri R. , Albertini E. , Favaron E. , Zignani M. , Orteschi D. , Bianchi P. , Faravelli F. , Forzano F. , Seri M. , Wischmeijer A. , Turchetti D. , Pompilii E. , Gnoli M. , Cocchi G. , Mazzanti L. , Bergamaschi R. , De Brasi D. , Sperandeo M.P. , Mari F. , Uliana V. , Mostardini R. , Cecconi M. , Grasso M , Sassi S. , Sebastio G. , Renieri A. , Silengo M. , Bernasconi S. , Wakamatsu N. , Neri G.
Published: February 2009

Mowat–Wilson syndrome (MWS; OMIM #235730) is a genetic condition caused by heterozygous mutations or deletions of the ZEB2 gene, and characterized by typical face, moderate‐to‐severe mental retardation, epilepsy, Hirschsprung disease, and multiple congenital anomalies, including genital anomalies (particularly hypospadias in males), congenital heart defects, agenesis of the corpus callosum, and eye defects. Since the first delineation by Mowat et al. [Mowat et al. (1998); J Med Genet 35:617–623], ∼179 patients with ZEB2 mutations, deletions or cytogenetic abnormalities have been reported primarily from Europe, Australia and the United States. Genetic defects include chromosome 2q21–q23 microdeletions (or different chromosome rearrangements) in few patients, and ZEB2 mutations in most. We report on clinical and genetic data from 19 Italian patients, diagnosed within the last 5 years, including six previously published, and compare them with patients already reported. The main purpose of this review is to underline a highly consistent phenotype and to highlight the phenotypic evolution occurring with age, particularly of the facial characteristics. The prevalence of MWS is likely to be underestimated. Knowledge of the phenotypic spectrum of MWS and of its changing phenotype with age can improve the detection rate of this condition. © 2009 Wiley‐Liss, Inc.
Preparation and anticorrosive properties of hybrid coatings based on epoxy‐silica hybrid materials
Authors: Huang Kuan‐Yeh , Weng Chang‐Jian , Lin Su‐Yin , Yu Yuan‐Hsiang , Yeh Jui‐Ming
Published: February 2009

A series of sol‐gel derived organic–inorganic hybrid coatings consisting of organic epoxy resin and inorganic silica were successfully synthesized through sol‐gel approach by using 3‐glycidoxypropyl‐trimethoxysilane as coupling agent. Transparent organic–inorganic hybrid sol‐gel coatings with different contents of silica were always achieved. The hybrid sol‐gel coatings with low silica loading on cold‐rolled steel coupons were found much superior improvement in anticorrosion efficiently. The as‐synthesized hybrid sol‐gel materials were characterized by Fourier‐transformation infrared spectroscopy, 29Si‐nuclear magnetic resonance spectroscopy and transmission electron microscopy. Effects of the material composition of epoxy resins along with hybrid materials on the thermal stability, Viscoelasticity properties and surface morphology were also studied, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Application of fractional calculus to the modeling of the complex magnetic susceptibility for polymeric‐magnetic nanocomposites dispersed into a liquid media
Authors: Reyes‐Melo M. E. , Garza‐Navarro M. A. , González‐González V. A. , Guerrero‐Salazar C. A. , Martínez‐Vega J. , Ortiz‐Méndez U.
Published: February 2009

The objective of the present work is to develop a fractional model which describe in a precisely manner the real and imaginary parts of the complex magnetic susceptibility for polymer‐magnetic nanocomposites dispersed into a liquid media, using differential and/or integral operators of fractional order (fractional calculus). The theoretical results show that the shape of the curves of both real and imaginary parts is depending of the fractional order of this new model named Fractional Magnetic Model (FMM). Moreover, the comparison between theoretical and experimental results show that the FMM describe quite well the complex susceptibility response of the polymeric systems containing magnetic nanoparticles at low frequencies (from 0.1 to 105 Hz). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Water‐blown soy polyol based polyurethane foams modified by cellulosic materials obtained from different sources
Authors: Banik Indranil , Sain Mohini M.
Published: February 2009

This article deals with the effect of cellulosic fiber from commercially available writing paper, bleached kraft pulp, and commercially available rice flour on the foaming of polyurethane based on polyol derived from soy bean oil. The presence of cellulosic materials was observed to have a notable influence on the density of the foams. Changes in the density of different foams were correlated with possible chemical structures generated in the presence of the fiber and were analyzed by Fourier transform infrared spectroscopy and thermogravimetric analysis. Furthermore, differential scanning calorimetry analysis was performed to lend support to possible changes in foaming behavior in the presence of refined fiber. Scanning electron microscopy observations were in line with the observation of structures generated in the presence of cellulosic fibers from different sources. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of 3‐benzothiazolthio‐1‐propyltriethoxylsilane and its reinforcement for styrene–butadiene rubber/silica composites
Authors: Peng Hualong , Liu Lan , Luo Yuanfang , Hong Haoqun , Jia Demin
Published: February 2009

A novel block mercaptosilane (3‐benzothiazolthio‐1‐propyltriethoxylsilane) (Silane‐M) was synthesized and characterized by Fourier transform infrared spectra, 1H nuclear magnetic resonance, and elemental analysis. Styrene–butadiene rubber (SBR)/silica composites were prepared with Silane‐M, and its effect on the properties of materials was studied. Results show that Silane‐M can substantially improve the dispersion of silica and strengthen the reinforcement of silica for SBR vulcanizates like anchors of silica to rubber matrix. As expected, it enhances the tensile, tear strength, dynamic compression property, and resistance to abrasion of SBR/silica composites. By adding Silane‐M into the system, SBR/silica composites get superior skid resistance and high glass transition temperature (Tg). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation and characterization of scleroglucan drug delivery films: The effect of freeze‐thaw cycling
Authors: François Nora J. , Daraio Marta E.
Published: February 2009

This study examined the effect of the freeze‐thaw process on the physical properties of films prepared from scleroglucan (Scl) hydrogels, suitable for drug delivery applications. Films made from Scl, using glycerol as plasticizer, were prepared from hydrogels by two procedures: a room temperature drying (RTD) method and a freeze‐thaw cyclic process, before the application of RTD, which results in a reinforced physically cross‐linked network. Films were characterized by studies of water vapor transmission (WVT), swelling, tensile tests, ESEM microscopy, FTIR, and drug release measurements. These determinations showed significant differences between films obtained by both treatments. The films prepared through freeze‐thaw cycles showed an important increase of the tensile strength with respect to those corresponding to films only air dried and a decreasing swelling degree in direct relationship to the number of freeze‐thaw cycles. A model drug, Theophylline, was included in these biocompatible films for in vitro drug release measurements, using a flat Franz cell. The physical differences observed between Scl films prepared with both methods can be explained proposing that the number of crosslinking points by hydrogen bonding increase when increasing the number of freezing and thawing cycles used for film preparation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Electrical conductivities of photochemically prepared polyethylene glycol dimethacrylate, reacted with iodine and lithium perchlorate dopants and activation energy determination for polymer‐dopant interaction
Authors: Ramelow Ulku S. , Braganza Samantha N. , Ramelow Gerald J.
Published: February 2009

Conductive polymers were obtained by using a new polymerization method where UV‐light was used as a photochemical initiator. To obtain high percent conversion optimum irradiation times were determined. Since it was observed in a previous work that conductivity of some polymeric materials can be improved by the addition of dopants (Ramelow et al., Mat Res Innovat 2001, 5, 40; Ma et al., Tr J Chem 1997, 21, 313), in this work, the effect of dopants on conductivity of the polyethylene glycol dimethacrylate (PEGDM) was studied by using lithium perchlorate (LiClO4) and iodine (I2). The most effective dopant concentration was determined by measuring the conductivities. The conductivity change at various temperatures was traced during the reaction of PEGDM with dopant Lithium perchlorate (LiClO4) and the activation energy of dopant‐polymer interactions was calculated. A method was developed to follow the kinetics of polymerization reactions by tracing conductivity changes with time at different temperatures. The polymerization pathway of ethylene glycol dimethacrylate was given in a previous work, and the mechanism was studied by using NMR and relaxation time method (Ramelow et al., J Appl Polym Sci 2006, 100, 5087). In this work, the suggested pathway was confirmed by additional calculations. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Processing and characterization of poly(lactic acid) films plasticized with commercial adipates
Authors: Martino V. P. , Jiménez A. , Ruseckaite R. A.
Published: February 2009

The high brittleness of Poly(lactic acid) is a major drawback for flexible food packaging applications. The aim of this work is to evaluate the potential use of commercial adipates as PLA plasticizers to obtain transparent films with enhanced mechanical properties. Processing conditions were optimized. The effect of plasticizers was characterized by a decrease on the glass transition temperature and an increase in PLA chains mobility, which induced crystallization on heating. Thermal stability was not significantly affected, and mechanical properties showed an increase in ductility with the plasticizer content. Oxygen transmission rate was also measured to evaluate the effect of the microstructures generated by the presence of these additives in PLA‐based films. The monomeric adipate presented lack of homogeneity that makes films plasticized with this additive not useful for the intended application. Good compatibility was observed between polyadipates (up to 20 wt %) and the matrix, making them promising materials for biodegradable films manufacturing. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Methylenetetrahydrofolate reductase deficiency and low dietary folate increase embryonic delay and placental abnormalities in mice
Authors: Pickell Laura , Li Deqiang , Brown Katharine , Mikael Leonie G. , Wang Xiao‐Ling , Wu Qing , Luo Li , Jerome‐Majewska Loydie , Rozen Rima
Published: February 2009

BACKGROUND:Despite extensive research on mild methylenetetrahydrofolate reductase (MTHFR) deficiency and low dietary folate in different disorders, the association of these metabolic disturbances with a variety of congenital defects and pregnancy complications remains controversial. In this study we investigated the effects of MTHFR and dietary folate deficiency at 10.5 days post coitum (dpc) in our mouse model of mild MTHFR deficiency.METHODS:Mthfr+/+ and +/− female mice were fed a control or folic acid–deficient diet for 6 weeks, then mated withMthfr+/− males. At 10.5 dpc, embryos were examined and placentae were collected for histologic evaluation.RESULTS:Maternal MTHFR and folate deficiencies resulted in increased developmental delays and smaller embryos. We also observed a low frequency of a variety of embryonic defects in the experimental groups, such as neural tube, heart looping, and turning defects; these results mimic the low incidence and multifactorial nature of these anomalies in humans. Folate‐deficient mice also had increased embryonic losses and severe placental defects, including placental abruption and disturbed patterning of placental layers. Folate‐deficient placentae had decreased ApoA‐I expression, and there was a trend toward a negative correlation between ApoA‐I expression with maternal homocysteine concentrations.CONCLUSIONS:Our study provides biological evidence linking maternal MTHFR and dietary folate deficiencies to adverse pregnancy outcomes in mice. It underscores the importance of folate not only in reducing the incidence of early embryonic defects, but also in the prevention of developmental delays and placental abnormalities that may increase susceptibility to other defects and to reproductive complications. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.