bluuebunny/crossref_metadata_2025 huggingface dataset:
Micro‐Raman characterization of laser‐induced local thermo‐oxidation of thin chromium films
Authors: Baranov A. V. , Bogdanov K. V. , Fedorov A. V. , Yarchuk M. V. , Ivanov A. I. , Veiko V. P. , Berwick K.
Published: March 2011

Micro‐Raman spectroscopy was applied to the characterization of the chemical composition and topography of protective oxide layers formed under atmospheric conditions on the surface of thin chromium films. Strips of the layers were produced by local thermal heating using focused sub‐picosecond pulsed laser radiation. It is shown that a CrO2 layer is initially formed on the chromium surface at low light exposures. Increasing the exposure results in the transformation of the CrO2 layer to Cr2O3. The influence of the etching conditions on the composition and thickness of the oxide layers is investigated. The topography of the CrO2 and Cr2O3 oxide layers in transverse sections of the strips is demonstrated by the Raman mapping. Copyright © 2011 John Wiley & Sons, Ltd.
Determinants of Spending: an Evaluation of Three Major Sporting Events
Authors: Saayman Melville , Saayman Andrea
Published: March 2011

South Africa plays host to a number of major sporting events that takes place annually such as the Two Oceans Marathon, the Argus Cycle Tour and the Midmar open water mile. This research aims to identify the socio‐economic differences of participants in the events and to determine the key drivers of their spending. Three surveys were conducted at the events during 2008 and 2010. The data analyses include a factor and a regression analyses. The analyses identified the different motives why participation takes place, the socio‐demographic differences between participants and the impact thereof on spending. Copyright © 2011 John Wiley & Sons, Ltd.
Apparent exchange rate mapping with diffusion MRI
Authors: Lasič Samo , Nilsson Markus , Lätt Jimmy , Ståhlberg Freddy , Topgaard Daniel
Published: March 2011

Water exchange through the cell membranes is an important feature of cells and tissues. The rate of exchange is determined by factors such as membrane lipid composition and organization, as well as the type and activity of aquaporins. A method for noninvasively estimating the rate of water exchange would be useful for characterizing pathological conditions, e.g., tumors, multiple sclerosis, and ischemic stroke, expected to be associated with a change of the membrane barrier properties. This study describes the filter exchange imaging method for determining the rate of water exchange between sites having different apparent diffusion coefficients. The method is based on the filter‐exchange pulsed gradient spin‐echo NMR spectroscopy experiment, which is here modified to be compatible with the constraints of clinical MR scanners. The data is analyzed using a model‐free approach yielding maps of the apparent exchange rate, here being introduced in analogy with the concept of the apparent diffusion coefficient. Proof‐of‐principle experiments are performed on microimaging and whole‐body clinical scanners using yeast suspension phantoms. The limitations and appropriate experimental conditions are examined. The results demonstrate that filter exchange imaging is a fast and reliable method for characterizing exchange, and that it has the potential to become a powerful diagnostic tool. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
In vivo 31P spectroscopy by fully adiabatic extended image selected in vivo spectroscopy: A comparison between 3 T and 7 T
Authors: Bogner W. , Chmelik M. , Andronesi O. C. , Sorensen A. G. , Trattnig S. , Gruber S.
Published: March 2011

An improved image selected in vivo spectroscopy (ISIS) sequence for localized 31P magnetic resonance spectroscopy at 7 T was developed. To reduce errors in localization accuracy, adiabatic excitation, gradient offset independent adiabatic inversion pulses, and a special extended ISIS ordering scheme were used. The localization accuracy of extended ISIS was investigated in phantoms. The possible spectral quality and reproducibility in vivo was explored in a volunteer (brain, muscle, and liver). A comparison between 3 T and 7 T was performed in five volunteers. Adiabatic extended ISIS provided high spectral quality and accurate localization. The contamination in phantom experiments was only ∼5%, even if a pulse repetition time ∼ 1.2·T1 was chosen to maximize the signal‐to‐noise ratio per unit time. High reproducibility was found in the calf muscle for 2.5 cm isotropic voxels at 7 T. When compared with 3 T, localized 31P magnetic resonance spectroscopy in the human calf muscle at 7 T provided ∼3.2 times higher signal‐to‐noise ratio (as judged from phosphocreatine peak amplitude in frequency domain after matched filtering). At 7 T, extended ISIS allowed the performance of high‐quality localized 31P magnetic resonance spectroscopy in a short measurement time (∼3 to 4 min) and isotropic voxel sizes of ∼2.5 to 3 cm. With such short measurement times, localized 31P magnetic resonance spectroscopy has the potential to be applied not only for clinical research but also for routine clinical practice. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
A uniformly optimal‐order error estimate for a bilinear finite element method for degenerate convection‐diffusion equations
Authors: Jia Jinhong , Lu Tongchao , Wang Kaixin , Wang Hong , Ren Yongqiang
Published: March 2011

We prove an optimal‐order error estimate in a degenerate‐diffusion weighted energy norm for bilinear Galerkin finite element methods for two‐dimensional time‐dependent convection‐diffusion equations with degenerate diffusion. In the estimate, the generic constants depend only on certain Sobolev norms of the true solution but not the lower bound of the diffusion. This estimate, combined with a known stability estimate of the true solution of the governing partial differential equations, yields an optimal‐order estimate of the Galerkin finite element method, in which the generic constants depend only on the Sobolev norms of the initial and right side data. Preliminary numerical experiments were conducted to verify these estimates numerically. © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2011
Graded mesh refinement and error estimates of higher order for DGFE solutions of elliptic boundary value problems in polygons
Authors: Feistauer Miloslav , Sändig Anna‐Margarete
Published: March 2011

Error estimates for DGFE solutions are well investigated if one assumes that the exact solution is sufficiently regular. In this article, we consider a Dirichlet and a mixed boundary value problem for a linear elliptic equation in a polygon. It is well known that the first derivatives of the solutions develop singularities near reentrant corner points or points where the boundary conditions change. On the basis of the regularity results formulated in Sobolev–Slobodetskii spaces and weighted spaces of Kondratiev type, we prove error estimates of higher order for DGFE solutions using a suitable graded mesh refinement near boundary singular points. The main tools are as follows: regularity investigation for the exact solution relying on general results for elliptic boundary value problems, error analysis for the interpolation in Sobolev–Slobodetskii spaces, and error estimates for DGFE solutions on special graded refined meshes combined with estimates in weighted Sobolev spaces. Our main result is that there exist a local grading of the mesh and a piecewise interpolation by polynoms of higher degree such that we will get the same order O (hα) of approximation as in the smooth case. © 2011 Wiley Periodicals, Inc. Numer Mehods Partial Differential Eq, 2012
Connections between discontinuous Galerkin and nonconforming finite element methods for the Stokes equations
Authors: Becker Roland , Capatina Daniela , Joie Julie
Published: March 2011

We study a discontinuous Galerkin finite element method (DGFEM) for the Stokes equations with a weak stabilization of the viscous term. We prove that, as the stabilization parameter γ tends to infinity, the solution converges at speed γ−1 to the solution of some stable and well‐known nonconforming finite element methods (NCFEM) for the Stokes equations. In addition, we show that an a posteriori error estimator for the DGFEM‐solution based on the reconstruction of a locally conservative H(div, Ω)‐tensor tends at the same speed to a classical a posteriori error estimator for the NCFEM‐solution. These results can be used to affirm the robustness of the DGFEM‐method and also underline the close relationship between the two approaches. © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2011
Two‐level discretization of the Navier‐Stokes equations with r‐Laplacian subgridscale viscosity
Authors: Borggaard Jeff , Iliescu Traian , Roop John Paul
Published: March 2011

The r‐Laplacian has played an important role in the development of computationally efficient models for applications, such as numerical simulation of turbulent flows. In this article, we examine two‐level finite element approximation schemes applied to the Navier‐Stokes equations with r‐Laplacian subgridscale viscosity, where r is the order of the power‐law artificial viscosity term. In the two‐level algorithm, the solution to the fully nonlinear coarse mesh problem is utilized in a single‐step linear fine mesh problem. When modeling parameters are chosen appropriately, the error in the two‐level algorithm is comparable to the error in solving the fully nonlinear problem on the fine mesh. We provide rigorous numerical analysis of the two‐level approximation scheme and derive scalings which vary based on the coefficient r, coarse mesh size H, fine mesh size h, and filter radius δ. We also investigate the two‐level algorithm in several computational settings, including the 3D numerical simulation of flow past a backward‐facing step at Reynolds number Re = 5100. In all numerical tests, the two‐level algorithm was proven to achieve the same order of accuracy as the standard one‐level algorithm, at a fraction of the computational cost. © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2011
Revisiting the risk for aneuploidy in fetuses with isolated pyelectasis
Authors: Carbone Jeanine F. , Tuuli Methodius G. , Dicke Jeffrey M. , Macones George A. , Odibo Anthony O.
Published: March 2011

Objective

Previous studies are contradictory with regard to the association of isolated pyelectasis and aneuploidy. Our objective was to test the hypothesis that isolated pyelectasis is associated with aneuploidy and calculate likelihood ratios using a large ultrasound database.

Methods

A retrospective cohort study of pregnancies presenting to our prenatal ultrasound unit at 16 to 22 weeks was conducted. Pyelectasis was defined as fetal renal pelvis> 4 mm in the anterior‐posterior dimension. Fetuses with co‐existing major structural anomalies or markers of aneuploidy were excluded. Association between isolated pyelectasis and aneuploidy was assessed and screening efficiency was evaluated. Results were also stratified by maternal age.

Results

Among 62 103 patients who had obstetric ultrasounds during the study period, 1055 (1.7%) were diagnosed with isolated pyelectasis. The presence of isolated pyelectasis was significantly associated with any aneuploidy [OR 1.93 (CI 1.06–3.54)], and specifically trisomy 21 (T21) [OR 2.91 (CI 1.48–5.71)]. There was a greater than two‐fold increase in the risk of T21 in the presence of isolated pyelectasis [LR+ 2.44 (CI 1.28–4.64)].

Conclusions

Our data confirm a significant association between isolated pyelectasis and increased risk of aneuploidy, particularly T21. These likelihood ratios can be used to adjust aneuploidy risk and in counseling patients regarding appropriateness of amniocentesis. Copyright © 2011 John Wiley & Sons, Ltd.
Effect of molecular structure and rheology on the compression foam molding of ethylene‐α‐olefin copolymers
Authors: Zhang Ying , Kontopoulou Marianna , Ansari Mahmoud , Hatzikiriakos Savvas , Park Chul B.
Published: March 2011

The morphology and mechanical properties of foams made out of a series of ethylene‐α‐olefin copolymers having well‐characterized rheological properties were investigated. A compression foaming molding technique was implemented, using azodicarbonamide as the blowing agent. The polymers differed in the amount of comonomer contained (resulting in a range of densities), type of comonomer (octene vs. butene) and molecular weight, resulting in variable thermal properties and different rheological responses under shear and extensional flow. The results showed that the majority of the octene‐based copolymers with comparable rheological properties had similar foam morphology. A distinct behaviour was observed for the butene‐based copolymer, as well as the octene‐containing one having the lowest density and lowest melting/crystallization points. The poor foamability of these grades was attributed to their differences in extensional and thermal properties, respectively. Increasing density resulted in a higher secant modulus of the foamed samples. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
A proposed technique to improve the filling of the mold cavity by polymer during injection molding
Authors: Hassan Hamdy , Regnier Nicolas , George Jean‐Marie , Defaye Guy , Arquis Eric
Published: March 2011

In this study, a technique is proposed to improve the filling process of the injection molding and minimize the solidification during the filling to achieve a complete filling of the mold cavity. Two methods are proposed: stopping the flow rate of the cooling fluid or passing cooling fluid inside the cooling channels at higher temperature during a period of the injection molding cycle. The configuration studied consists of the mold with cuboids‐shape cavity having two different thicknesses. A validation of the numerical model used by an experimental work is presented. The results show that, stopping of cooling fluid on a period of injection cycle has not great effect on the improvement of injection cycle. The results indicate that passing coolant fluid at higher temperature during the ejection stage decreases the solidification of the polymer during the filling stage by about 40%. © POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers.
The influence of DMDBS on the morphology and mechanical properties of polypropylene cast films
Authors: Sreenivas K. , Pol Harshawardhan V. , Kumaraswamy Guruswamy
Published: March 2011

We investigate extrusion film casting (EFC) of polypropylene (PP) and examine the effects of varying the concentration of nucleating agent, dimethyl dibenzylidene sorbitol (DMDBS); melt temperature at the die exit; and the draw ratio. Addition of DMDBS increases the PP crystallization temperature, and consequently the PP lamellar repeat spacing. For the draw ratios explored, we do not observe any substantial orientation of iPP crystals for films of neat iPP. However, addition of DMDBS results in the formation of oriented PP crystals, with greater orientation for higher draw ratios. On cooling from the melt, a network of DMDBS nanofibers forms in the PP. We believe that flow‐alignment of this DMDBS network templates the orientation of PP crystals. We observe that the tensile modulus and yield stress increase with PP crystal orientation. However, at high DMDBS concentrations (0.8%), films have poor mechanical strength due to formation of voids and defects. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Preparation and crystallization behavior of multiwalled carbon nanotubes/poly(vinyl alcohol) nanocomposites
Authors: Zhu Yilei , Du Zhongjie , Li Hangquan , Zhang Chen
Published: March 2011

The poly(vinyl alcohol) (PVA)‐based nanocomposites embedded with modified multiwalled carbon nanotubes (MWCNTs) were prepared. To enhance the interfacial interaction between MWCNTs and PVA, acid‐treated MWCNTs were grafted with PVA chains, compatibilizing MWCNTs and the matrix. The better dispersion of MWCNTs in PVA matrix was obtained by the introduction of MDI reaction bridges and then PVA molecules onto the surface of MWCNTs. Moreover, strong interaction between MWCNTs and PVA matrix was evidenced through the measurement results of the melting behavior, polarized Raman measurement, and nonisothermal crystallization behavior of the nanocomposites. Owing to the reinforcement of MWCNTs, the tensile strength and modulus of PVA nanocomposite containing 0.9 wt% MWCNTs were increased by 160.7 and 109.2%, respectively, compared to neat PVA. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
One‐pot synthesis of polyamide 12,T–polyamide‐6 block copolymers
Authors: Novitsky Theodore F. , Mathias Lon J.
Published: March 2011

Polyamide 12,T–polyamide‐6 (PA‐12,T–PA‐6) block copolymers were synthesized by anionic polymerization of caprolactam using a PA‐12,T macrocoinitiator (McI). PA‐12,T McI and its precursors are soluble in molten caprolactam allowing for both the McI step‐growth polymerization and anionic polymerization to be performed in one‐pot. It was found that the competing reaction rates of caprolactam ring‐opening polymerization and McI transamidation are both deterred by a common ion effect using CaCl2 and soluble materials were obtained using >1 mol % CaCl2. Without CaCl2, the reaction mixture solidifies in less than 30 s and produces crosslinked materials. To understand this effect, PA‐12,T McI reactions with caprolactam were performed with 1–10 mol % CaCl2, and polymer structures were characterized using 13C NMR and dilute solution viscometry. These data were then correlated with unique thermal properties and swelling behavior of the block copolymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Novel suberin‐based biopolyesters: From synthesis to properties
Authors: Sousa Andreia F. , Gandini Alessandro , Silvestre Armando J. D. , Neto Carlos Pascoal , Cruz Pinto José J. C. , Eckerman Christer , Holmbom Bjarne
Published: March 2011

This article reports the successful synthesis and characterization of two types of completely biobased polymers prepared by the polycondensation or polytransesterification of suberin fragments, isolated by different procedures and from two different vegetable sources. These polymerizations were conducted with different experimental conditions in terms of the type of catalyst, the reaction medium and temperature, as well as the molar ratio between the reactive moieties. The ensuing linear or partly crosslinked polyesters were characterized by conventional spectroscopic techniques, SEC, DSC, XRD, DMA, and TGA. These hydrophobic materials represent an original contribution to the growing field of polymers from renewable resources. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Enhancement of OFET performance of semiconducting polymers containing benzodithiophene upon surface treatment with organic silanes
Authors: Sista Prakash , Bhatt Mahesh P. , Mccary Ashton R. , Nguyen Hien , Hao Jing , Biewer Michael C. , Stefan Mihaela C.
Published: March 2011

Poly{4,8‐bis(4‐decylphenylethynyl)benzo[1,2‐b:4,5‐b′]dithiophene} (P1) homopolymer and poly{4,8‐bis(4‐decylphenylethynyl)benzo[1,2‐b:4,5‐b′]dithiophene ‐alt‐thiophene} (P2) alternating copolymer have been synthesized by Stille coupling polymerization. The field‐effect mobilities of both polymers were measured on both untreated and silane‐treated OFET devices. Various silanes were selected to allow an incremental increase in the hydrophobicity of the silicon dioxide dielectric. A direct correlation was observed between the hydrophobicity of the silicon dioxide dielectric surface and the enhancement of the field‐effect mobilities. The highest mobilities for both polymers were measured on the OFET devices treated with heptadecafluoro‐1,1,2,2‐tetrahydro‐decyl‐1‐trimethoxysilane (FS) which generated the most hydrophobic surface. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Screening for distress and depression in cancer settings: 10 lessons from 40 years of primary‐care research
Authors: Mitchell Alex J. , Vahabzadeh Arshya , Magruder Kathryn
Published: March 2011

Objective: There has been at least 40 years of active research on screening for depression and distress in primary care. Both successes and failures have been documented. The purpose of this focussed narrative review was to summarise this research and present the key lessons for clinicians and researchers working in psychosocial oncology.

Methods: We searched for studies assessing the utility of screening in primary care in seven electronic bibliographic databases (CENTRAL, CINAHL, Embase, HMIC, Medline, PsycINFO, Web of Knowledge) from inception to December 2010. Results were reviewed and summarised into key areas.

Results: We found that research could be distilled into the following key learning points. (1) Primary care is an important partner in psychosocial care. (2) Both over and under detection are problematic. (3) Barriers to identification involve patient and clinician factors. (4) Acceptability of screening is critical to implementation. (5) Underserved groups need special attention in screening. (6) Patient–clinician trust is an important modifiable variable. (7) Greater contact influences detection. (8) Clinician confidence/skills influence screening success and subsequent action. (9) Training may improve confidence but effects upon long‐term outcomes are modest. (10) Screening is generally ineffective without aftercare.

Conclusions: Primary care has shown largely what does not work in relation to screening. Namely relying on clinicians' unassisted judgement without infrastructural support, using over‐complex scales with low acceptability, looking for depression alone, using screening without linked treatment, treating in the absence of follow‐up and failing to engage patients in their own care. These pitfalls can and should be avoided in psychosocial oncology. Copyright © 2011 John Wiley & Sons, Ltd.
Heterotic orbifold resolutions as (2,0) gauged linear sigma models
Authors: Groot Nibbelink S.
Published: March 2011

In this work we attempt to bridge the gap between heterotic orbifold models and Calabi‐Yau compactifications using gauged linear sigma models (GLSMs) with (2,0) worldsheet supersymmetry. We associate a specific GLSM to a heterotic orbifold model with twisted states that have non‐vanishing vacuum expectation values (VEVs): The charges of the GLSM superfields are essentially determined by the shifted momenta of these states. When a twisted state contains an oscillator excitation, a fermionic gauging is introduced on the worldsheet, inducing a non‐Abelian gauge bundle, e.g. the standard embedding. However, irrespectively of whether the twisted states contain oscillators or not, they can be interpreted as blow‐up modes, as their VEVs are correlated with sizes of exceptional cycles in the resolved geometry. We show that the GLSM anomaly cancellation conditions ensure that the Bianchi identities are fulfilled for all possible triangulations of a resolution. By considering marginal deformations of a GLSM in the large volume limit we are able to directly determine its effective four dimensional spectrum. In the cases considered the spectra coincide with those computed via index theorems.
Enzymatic activity of free‐prostate‐specific antigen (f‐PSA) is not required for some of its physiological activities
Authors: Chadha Kailash C. , Nair Bindukumar B. , Chakravarthi Srikant , Zhou Rita , Godoy Alejandro , Mohler James L. , Aalinkeel Ravikumar , Schwartz Stanley A. , Smith Gary J.
Published: March 2011

BACKGROUND

Prostate specific antigen (PSA) is a well known biomarker for early diagnosis and management of prostate cancer. Furthermore, PSA has been documented to have anti‐angiogenic and anti‐tumorigenic activities in both in vitro and in vivo studies. However, little is known about the molecular mechanism(s) involved in regulation of these processes, in particular the role of the serine‐protease enzymatic activity of PSA.

METHODS

Enzymatic activity of PSA isolated directly from seminal plasma was inhibited specifically (>95%) by incubation with zinc2+. Human umbilical vein endothelial cells (HUVEC) were utilized to compare/contrast the physiological effects of enzymatically active versus inactive PSA.

RESULTS

Equimolar concentrations of enzymatically active PSA and PSA enzymatically inactivated by incubation with Zn2+ had similar physiological effects on HUVEC, including inhibiting the gene expression of pro‐angiogenic growth factors, like VEGF and bFGF, and up‐regulation of expression of the anti‐angiogenic growth factor IFN‐γ; suppression of mRNA expression for markers of blood vessel development, like FAK, FLT, KDR, TWIST‐1; P‐38; inhibition of endothelial tube formation in the in vitro Matrigel Tube Formation Assay; and inhibition of endothelial cell invasion and migration properties.

DISCUSSION

Our data provides compelling evidence that the transcriptional regulatory and the anti‐angiogenic activities of human PSA are independent of the innate enzymatic activity. Prostate 71:1680–1690, 2011. © 2011 Wiley‐Liss, Inc.
Combining novel monitoring tools and precision application technologies for integrated high‐tech crop protection in the future (a discussion document)
Authors: Zijlstra Carolien , Lund Ivar , Justesen Annemarie F , Nicolaisen Mogens , Jensen Peter Kryger , Bianciotto Valeria , Posta Katalin , Balestrini Raffaella , Przetakiewicz Anna , Czembor Elzbieta , de Zande Jan van
Published: March 2011

The possibility of combining novel monitoring techniques and precision spraying for crop protection in the future is discussed. A generic model for an innovative crop protection system has been used as a framework. This system will be able to monitor the entire cropping system and identify the presence of relevant pests, diseases and weeds online, and will be location specific. The system will offer prevention, monitoring, interpretation and action which will be performed in a continuous way. The monitoring is divided into several parts. Planting material, seeds and soil should be monitored for prevention purposes before the growing period to avoid, for example, the introduction of disease into the field and to ensure optimal growth conditions. Data from previous growing seasons, such as the location of weeds and previous diseases, should also be included. During the growing season, the crop will be monitored at a macroscale level until a location that needs special attention is identified. If relevant, this area will be monitored more intensively at a microscale level. A decision engine will analyse the data and offer advice on how to control the detected diseases, pests and weeds, using precision spray techniques or alternative measures. The goal is to provide tools that are able to produce high‐quality products with the minimal use of conventional plant protection products. This review describes the technologies that can be used or that need further development in order to achieve this goal. Copyright © 2011 Society of Chemical Industry
Diagnosis, treatment and prevention of Lyme borreliosis
Authors: Cochrane Alexandra , Williams Martin
Published: March 2011

Lyme borreliosis is a tick borne disease, endemic to forested and woodland areas, with multiple clinical presentations. Here the authors outline the diagnosis and treatment of the most common manifestations and discuss its prevention. Copyright © 2011 Wiley Interface Ltd
Oleanolic Acid and Ursolic Acid Derived from Cornus officinalis Sieb. et Zucc. Suppress Epidermal Growth Factor‐ and Phorbol Ester‐induced MUC5AC Mucin Production and Gene Expression from Human Airway Epithelial Cells
Authors: Cho Kyoungrai , Lee Hyun Jae , Lee Su Yel , Woo Hoonyoung , Lee Mi Nam , Seok Jeong Ho , Lee Choong Jae
Published: March 2011

In this study, the effects of oleanolic acid and ursolic acid on MUC5AC mucin production and gene expression induced by epidermal growth factor (EGF) and phorbol 12‐myristate 13‐acetate (PMA) from human airway epithelial cells were investigated. Confluent NCI‐H292 cells were pretreated with each agent for 30 min and then stimulated with EGF and PMA for 24 h, respectively. MUC5AC mucin gene expression and mucin protein production were measured by RT‐PCR and ELISA. Oleanolic acid and ursolic acid were found to inhibit the production of MUC5AC mucin protein induced by EGF and PMA, and both compounds also inhibited the expression of MUC5AC mucin gene induced by EGF and PMA. These results suggest that oleanolic acid and ursolic acid can regulate mucin gene expression, and production of mucin protein, by directly acting on airway epithelial cells. Copyright © 2011 John Wiley & Sons, Ltd.
RESPONSES OF BENTHIC INVERTEBRATES TO ABRUPT CHANGES OF TEMPERATURE IN FLUME SIMULATIONS
Authors: Carolli M. , Bruno M. C. , Siviglia A. , Maiolini B.
Published: March 2011

Sudden instream releases of hypolimnetic water from hydropower plants (i.e. hydropeaking) can cause abrupt temperature variations (i.e. thermopeaking), typically on a daily basis. We investigated the thermopeaking effects on benthic invertebrate drift by simulating abrupt thermal shifts in experimental flumes. We conducted two cold thermopeaking and two warm thermopeaking simulations by quickly cooling the water by 3–4°C during the warm season and by warming the water by 2–3°C during the cold season at a rate of about 2.4 × 10−1°C min−1. This rate is very similar to those associated with hydropeaking waves in rivers in the same watershed as the experimental flumes. Although the achieved changes in temperature were within a tolerability range for benthic invertebrates, their drift increased threefold and fivefold, and twofold and fourfold in the two cold and two warm thermopeaking experiments, respectively. Assemblage composition of drift before and during the experiment differed, indicating that some taxa respond to abrupt thermal alterations. Larvae of Chironomidae, Simuliidae and Baetidae were the most abundant drifting taxa in all experiments during temperature alterations. The drift induced was probably behavioural, given the immediate responses of invertebrates that begun to drift within 2 min from the start of the simulations. This type of drift differs from catastrophic drift that usually occurs as a response to hydropeaking. The two types of drift can occur as distinct events in streams impacted by hydropower plants with high‐elevation reservoirs and hypolimnetic releases because the propagation of the discharge and thermal waves are asynchronous, causing the benthic community to undergo two distinct but consecutive impacts. Our results suggest that the long‐term effects of thermopeaking are mixed and synergical with those caused by hydropeaking and, on the long term, may alter the longitudinal distribution of benthic communities. Copyright © 2011 John Wiley & Sons, Ltd.
Cell‐surface ultrastructural changes during the in vitro neuron‐like differentiation of rat bone marrow‐derived mesenchymal stem cells
Authors: Wang Xiaoping , He Dongmei , Chen Li , Chen Tongsheng , Jin Hua , Cai Jiye , Chen Yong
Published: March 2011

The neuron‐like differentiation of bone marrow‐derived mesenchymal stem cells (BMMSCs) has been extensively studied. However, the alternations of the cell‐surface ultrastructures and the membrane tension/reservoir of the cells during this differentiation process are poorly understood. Therefore, atomic force microscopy (AFM) was utilized in this study to observe the cell‐surface ultrastructural changes among rat bone marrow‐derived mesenchymal stem cells (rBMMSCs), partially differentiated cells, and fully differentiated neuron‐like cells. By analyzing the stiffness of plasma membranes, lamellipodial extensions, average heights of small membrane protrusions and relatively larger uplifted structures, and peak‐peak spacing among protrusions and/or uplifted structures, we found that the membrane reservoir may potentially decrease upon the differentiation from rBMMSCs to partially differentiated cells and to fully differentiated neuron‐like cells. The results may help to better understanding the membrane tension of various types of cells and related biological processes, such as membrane traffic, cell adhesion, motility, differentiation, among others. The data also implies that AFM may be a useful tool for evaluating membrane reservoir by imaging cell‐surface ultrastructures. SCANNING 33: 69–77, 2011. © 2011 Wiley Periodicals, Inc.
Evolving communication patterns in response to an acquisition event
Authors: Allatta Joan T. , Singh Harbir
Published: March 2011

This study uses network data of worker behavior to analyze changes in worker communication patterns during the first three years post‐acquisition. The findings suggest that new communication routines develop slowly and are not entirely enduring even when a transformative event, such as an acquisition, occurs. Communication across firms initially increases as workers change their routines. However, over time this communication peaks and then falls as workers develop common ground. Communication across firms was greater when workers' tasks were interdependent. Overall, this study demonstrates that communication routines persist even after an organizationally transforming event. It illustrates the importance of both the formal and informal organization as well as the promise of using social network methods and communication log data to study social phenomena of strategic interest. Copyright © 2011 John Wiley & Sons, Ltd.
Do switching costs mediate the relationship between entry timing and performance?
Authors: Gómez Jaime , Maícas Juan Pablo
Published: March 2011

The purpose of this paper is to test the effectiveness of switching costs as an isolating mechanism in the context of the first‐mover advantage theory. Whereas both the literature on switching costs and on pioneering propose this as a mechanism through which firms could obtain sustainable competitive advantage, other authors offer a rationale for thinking that this is not the case. We test our hypotheses in the context of the European mobile telecommunications industry. This is a sector that has been characterized by high rates of growth in the number of subscribers, which could reduce the effectiveness of switching costs from being effective as an isolating mechanism. Our results show that switching costs are an important tool through which first‐mover advantages materialize. Copyright © 2011 John Wiley & Sons, Ltd.
In vivo effects of pardoprunox (SLV308), a partial D2/D3 receptor and 5‐HT1A receptor agonist, on rat dopamine and serotonin neuronal activity
Authors: Bétry Cécile , Etiévant Adeline , Lambás‐Señas Laura , Mccreary Andrew C. , Haddjeri Nasser
Published: March 2011

The nonergot ligand pardoprunox (SLV308) is a dopamine (DA) D2/D3 and serotonin (5‐HT)1A receptor agonist and a new candidate for the treatment of Parkinson's disease. We used in vivo electrophysiological paradigm in the rat to assess the effects of pardoprunox on DA neuronal activity in ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) as well as on 5‐HT neuronal activity in dorsal raphe nucleus (DRN). In the VTA, pardoprunox (2–20 μg kg−1, i.v.) decreased partially the firing activity of DA neurons. Interestingly, the bursting activity of VTA DA neurons was completely suppressed. This compound both reversed and prevented the inhibition of firing rate induced by the full D2‐like receptor agonist apomorphine, confirming its partial D2‐like receptor agonistic property. Surprisingly in the SNc, pardoprunox (10 μg kg−1, i.v.) either partially or fully suppressed the firing activity in two separate populations of DA neurons. Finally, in the DRN, pardoprunox (5–40 μg kg−1, i.v.) completely suppressed the firing activity of 5‐HT neurons. Moreover, the selective 5‐HT1A receptor antagonist WAY‐100,635 prevented and reversed the effects of pardoprunox. The present study shows that pardoprunox acts in the VTA as a potent partial D2‐like receptor agonist reducing preferentially the burst activity linked to the phasic activity of DA neurons. Unexpectedly in the SNc, pardoprunox behaves either as apartial or a full D2‐like receptor agonist. Finally in the DRN, pardoprunox is a potent full 5‐HT1A receptor agonist. Hence, this in vivo study suggests that pardoprunox represents a promising approach for the treatment of Parkinson's disease. Synapse, 2011. © 2011 Wiley‐Liss, Inc.
Rückseitenmetallisierung Wafer‐basierter Si‐Solarzellen mittels EB‐PVD
Authors: Reinhold Ekkehart , Faber Jörg , Otto Falk
Published: March 2011

Mit dem Elektronenstrahlverdampfen ist eine neuartige Beschichtungstechnologie für die Rückseitenmetallisierung von Wafer‐basierten Si‐Solarzellen ins Blickfeld gekommen. Die Motivation ergibt sich aus dem Kostendruck im Wettbewerb mit der Dünnschicht‐Photovoltaik und dem Kosteneinsparpotenzial durch Anwendung des Elektronenstrahlverdampfens. Der Beitrag stellt ein hochproduktives Anlagenkonzept näher vor und geht darauf ein, unter welchen Gesichtspunkten eine Anlagenkonzeptanpassung an die jeweils besonderen Solarzellen‐typischen Merkmale erforderlich ist. Außerdem werden verschiedene PVD‐Technologien hinsichtlich ihres Einsatzpotenzials für die Wafer‐Rückseitenmetallisierung miteinander verglichen. Herausforderungen bei der Einführung der Elektronenstrahl‐Verdampfungstechnologie und besondere Chancen, die ihr Einsatz eröffnet, werden betrachtet.
PECVD mit der Bandhohlkathode
Authors: Nikolov Krasimir , Schuhmacher Bernd , Jung Thomas , Klages Claus‐Peter
Published: March 2011

Niederdruck‐Glimmentladungen sind für die Entwicklung neuartiger Oberflächenmodifikationen und ‐beschichtungen von Stahlfeinblechen von großem Interesse. Die Herausforderungen bei der Integration der Plasmaprozesse in vorhandene kontinuierliche Beschichtungsprozesse von Feinblech bestehen in der Notwendigkeit von sehr hohen Behandlungsraten und minimalen parasitären Ablagerungen. Unter Berücksichtigung dieser Anforderungen wurde auf Basis einer scheibenförmigen Hohlkathode, die von den Substraten selbst gebildet wird, ein neuartiges Bandhohlkathodenverfahren (Strip Hollow Cathode – SHC) für die Oberflächenbehandlung entwickelt. Dieses Verfahren hat hohes Potenzial für die kontinuierliche Behandlung von Stahlband, was anhand unterschiedlicher Anwendungsbereiche aufgezeigt wird.
Charakterisierung von Schichten und Platten
Authors: Sklarczyk Christoph
Published: March 2011

Mit Hilfe von Mikrowellen lassen sich die unterschiedlichsten Werkstoffe in Form von Schichten, Platten oder Objekten komplexer Geometrie hinsichtlich ihrer Materialeigenschaften, Fehler und Geometrie charakterisieren. Die Prüfung erfolgt zerstörungsfrei und kann berührungslos und schnell durchgeführt werden. Im Durchstrahlungsmodus können nichtmetallische und elektrisch schwach leitende Werkstoffe bis zu einer Dicke von mehreren cm untersucht werden, metallische Werkstoffe dagegen je nach Leitfähigkeit bis zu einer Dicke von mehreren µm oder nm. Im Reflexionsmodus lassen sich auch elektrisch stärker leitende Materialien prüfen.
Prevalence of Primary Hyperparathyroidism and Impact on Bone Mineral Density in Elderly Men: MrOs Sweden
Authors: Siilin Helene , Lundgren Ewa , Mallmin Hans , Mellström Dan , Ohlsson Claes , Karlsson Magnus , Orwoll Eric , Ljunggren Östen
Published: March 2011

Background

Age and sex are of importance in the development of primary hyperparathyroidism (PHPT), and the disease is most common in postmenopausal women. Skeletal complications are well known at an advanced stage of PHPT, although the impact on bone mineral density (BMD) is evident in patients with mild disease. This study examines the prevalence of PHPT in elderly men and its impact on BMD.

Methods

Calcium homeostasis and BMD, measured by dual X‐ray absorptiometry, were evaluated in 3014 men ages 69 to 81 years in the MrOS‐Sweden cohort. Individuals with a low glomerular filtration rate (<21 ml/min/1.73 m2) and vitamin D deficiency (<50 nmol/l) were excluded. Among the remaining subjects, PHPT was assumed in subjects with above‐normal albumin‐adjusted serum (s)‐calcium and plasma intact parathyroid hormone (p‐iPTH) levels (PHPT group). BMD was compared between the PHPT group and men without PHPT. Subjects with inappropriately elevated iPTH (IEP group), based on both s‐calcium (2.34 mmol/l) and iPTH (4.24 pmol/l) levels being above the median level, were compared to the rest of the cohort.

Results

The prevalence of PHPT was estimated to be 0.73%. The mean BMD in the total hip and femoral neck was lower in the PHPT group than in the PHPT controls. Significantly lower BMD (p < 0.05) was seen in the IEP group (total hip and lumbar spine).

Conclusions

Elderly men appear to have a lower prevalence of PHPT than women at the same age. The impact of disturbed calcium homeostasis on BMD was also evident in this population group.
Structural basis of fumarate hydratase deficiency
Authors: Picaud Sarah , Kavanagh Kathryn L. , Yue Wyatt W. , Lee Wen Hwa , Muller‐Knapp Susanne , Gileadi Opher , Sacchettini James , Oppermann Udo
Published: March 2011

Fumarate hydratase catalyzes the stereospecific hydration across the olefinic double bond in fumarate leading to L‐malate. The enzyme is expressed in mitochondrial and cytosolic compartments, and participates in the Krebs cycle in mitochondria, as well as in regulation of cytosolic fumarate levels. Fumarate hydratase deficiency is an autosomal recessive trait presenting as metabolic disorder with severe encephalopathy, seizures and poor neurological outcome. Heterozygous mutations are associated with a predisposition to cutaneous and uterine leiomyomas and to renal cancer. The crystal structure of human fumarate hydratase shows that mutations can be grouped into two distinct classes either affecting structural integrity of the core enzyme architecture, or are localized around the enzyme active site.

An interactive version of this manuscript (which may contain additional mutations appended after acceptance of this manuscript) may be found on the SSIEM website at:http://www.ssiem.org/resources/structures/FH.
Pulmonary vascular disease in Gaucher disease: clinical spectrum, determinants of phenotype and long‐term outcomes of therapy
Authors: Lo Sarah Michelman , Liu Jun , Chen F. , Pastores G. M. , Knowles J. , Boxer M. , Aleck Kirk , Mistry Pramod K.
Published: March 2011

Pulmonary arterial hypertension (PAH) and hepatopulmonary syndrome (HPS) are rare pulmonary vascular complications of type 1 Gaucher disease (GD1). We examined GBA1 genotype, spleen status, Severity Score Index (SSI), and other patient characteristics as determinants of GD/PAH‐HPS phenotype. We also examined the long‐term outcomes of imiglucerase enzyme replacement therapy (ERT) +/− adjuvant therapies in 14 consecutive patients. We hypothesized a role of BMPR2 and ALK1 as genetic modifiers underlying GD/PAH‐HPS phenotype. Median age at diagnosis of GD1 was 5 yrs (2–22); PAH was diagnosed at median 36 yrs (22–63). There was a preponderance of females (ratio 5:2). ERT was commenced at median 36.5 yrs (16–53) and adjuvant therapy at 36 yrs (24–57). GBA1 genotype was N370S homozygous in two patients, N370S heteroallelic in 12. Median SSI was 15 (7–20). All patients had undergone splenectomy at median age 12 yrs (2–30). In three patients, HPS was the initial presentation, and PAH developed after its resolution; in these three, HPS responded dramatically to ERT. In seven patients, sequencing of the coding regions of BMPR2 and ALK1 was undertaken: 3/7 were heterozygous for BMPR2 polymorphisms; none harbored ALK1 variants. With ERT (± adjuvant therapy), 5/14 improved dramatically, five remained stable, two worsened, and two died prematurely. In this largest series of GD/PAH‐HPS patients, there is preponderance of females and N370S heteroallelic GBA1 genotype. Splenectomy appears essential to development of this phenotype. In some patients, HPS precedes PAH. BMPR2 and ALK1 appear not be modifier genes for this rare phenotype of GD. ERT +/− adjuvant therapy improves prognosis of this devastating GD phenotype.
Identification of ChIP-seq mapped targets of HP1β due to bombesin/GRP receptor activation
Authors: Tell Robert , Wang Q. Tian , Blunier Adam , Benya Richard V.
Published: March 2011

Epithelial cells lining the adult colon do not normally express gastrin-releasing peptide (GRP) or its receptor (GRPR). In contrast, GRP/GRPR can be aberrantly expressed in human colorectal cancer (CRC) including Caco-2 cells. We have previously shown that GRPR activation results in the up-regulation of HP1β, an epigenetic modifier of gene transcription. The aim of this study was to identify the genes whose expression is altered by HP1β subsequent to GRPR activation. We determined HP1β binding positions throughout the genome using chromatin immunoprecipitation followed by massively parallel DNA sequencing (ChIP-seq). After exposure to GRP, we identified 9,625 genomic positions occupied by HP1β. We performed gene microarray analysis on Caco-2 cells in the absence and presence of a GRPR specific antagonist as well as siRNA to HP1β. The expression of 97 genes was altered subsequent to GRPR antagonism, while the expression of 473 genes was altered by HP1β siRNA exposure. When these data were evaluated in concert with our ChIP-seq findings, 9 genes showed evidence of possible altered expression as a function of GRPR signaling via HP1β. Of these, genomic PCR of immunoprecipitated chromatin demonstrated that GRPR signaling affected the expression of IL1RAPL2, FAM13A, GBE1, PLK3, and SLCO1B3. These findings provide the first evidence by which GRPR aberrantly expressed in CRC might affect tumor progression.
American Missionaries and the Harem: Cultural Exchanges behind the Scenes
Authors: CEVIK GÜLEN
Published: March 2011

This article examines the impact on American furniture and clothing styles by women missionaries traveling to Turkey in the Victorian era. Although there has been much discussion of the impact of Western missionaries on Turkey and other parts of Asia, the reciprocal impact on American culture has not been adequately assessed. Missionary work, which started in the 1820s in a modest manner, turned into a systematic and large-scale activity, reaching its climax during the last quarter of the nineteenth century. Unlike Western diplomats, whose visits took place in the palaces of Istanbul, far from the realities of everyday life, missionary women had informal contact with ordinary Turkish women. Ottoman Turkish domestic space was highly gendered, so only these missionary women would have had access to authentic Ottoman Turkish interiors and been able to observe them as social spaces. The furniture style and the unique concept of comfort that they observed in Turkey presented an alternative point of view of home life and its organization. After spending years abroad, these women would return to the US to recruit and raise money for their missions by traveling from community to community, often creating interest for their work abroad by presenting examples of material culture. This article will put letters, diaries, travelogues and other contemporary material in the context of American culture of the Victorian era in order to chart the unusual way in which American and Turkish women interacted with each other at this historical moment.