bluuebunny/crossref_metadata_2025_split huggingface dataset:
High resolution three‐dimensional cine phase contrast MRI of small intracranial aneurysms using a stack of stars k‐space trajectory
Authors: Kecskemeti Steven , Johnson Kevin , Wu Yijing , Mistretta Charles , Turski Patrick , Wieben Oliver 
Published: February 2012

AbstractPurpose:To develop a method for targeted volumetric, three directional cine phase contrast (PC) imaging with high spatial resolution in clinically feasible scan times.Materials and Methods:A hybrid radial‐Cartesian k‐space trajectory is used for cardiac gated, volumetric imaging with three directional velocity encoding. Imaging times are reduced by radial undersampling and temporal viewsharing. Phase contrast angiograms are displayed in a new approach that addresses the concern of signal drop out in regions of slow flow. The feasibility of the PC stack of stars (SOS) trajectory was demonstrated with an in vivo study capturing 14 small intracranial aneurysms (2–10 mm). Aneurysm measures from six aneurysms also imaged with digital subtraction angiography (DSA) were compared with linear regression with those from the PC SOS images.Results:All aneurysms were identified on the phase contrast angiograms. The geometric measures from PC SOS and DSA were in good agreement (linear regression: slope = 0.89, intercept = 0.35, R∧2 = 0.88).Conclusion:PC SOS is a promising method for obtaining volumetric angiograms and cine phase contrast velocity measurements in three dimensions. Acquired spatial resolutions of 0.4 × 0.4 × (0.7–1.0) mm make this method especially promising for studying flow in small intracranial aneurysms. J. Magn. Reson. Imaging 2012. © 2012 Wiley Periodicals, Inc.
A proposal for the timing of management of patients with melanoma presenting during pregnancy
Authors: Broer Niclas , Buonocore Samuel , Goldberg Carolyn , Truini Carolyn , Faries Marc B. , Narayan Deepak , Ariyan Stephan 
Published: February 2012

AbstractThe treatment of melanoma during and immediately after pregnancy poses a significant challenge to surgeons, oncologists, and patients alike. With the overall increase in incidence of melanoma in the United States and worldwide, it is likely that more surgeons will be faced with management decisions regarding pregnant patients with melanoma. We report on five patients who presented to the Yale Melanoma Unit with melanoma during their pregnancy. We propose the management option of resection of the primary tumor under local anesthesia, and postponing of the sentinel lymph node biopsy until after the birth of the child. The completion lymphadenectomy can be performed if these nodes are found to be harboring metastases. We further discuss treatment options and propose an algorithm for management of patients diagnosed with melanoma while pregnant. J. Surg. Oncol. 2012; 106:36–40. © 2012 Wiley Periodicals, Inc.
Pulsed Light Irradiation Improves Behavioral Outcome in a Rat Model of Chronic Mild Stress
Authors: Wu Xingjia , Alberico Stephanie L. , Moges Helina , De Taboada Luis , Tedford Clark E. , Anders Juanita J. 
Published: February 2012

AbstractBackground and ObjectiveTranscranial laser therapy (TLT) has been used successfully for the treatment of stroke in animal models and clinical trials. These results support the hypothesis that TLT could be used to treat other central nervous system conditions, such as depression. Current therapy for depression emphasizes pharmaco‐therapeutics. However, these interventions often cause unwanted side effects. Here, TLT as a treatment for depression was studied in a rat model of chronic mild stress (CMS).Study Design/Material and MethodsWistar rats were randomized into four experimental groups (n = 8): (1) No‐stress; (2) stress without treatment (Stress); (3) stress treated with an antidepressant (Drug); and (4) stress treated with TLT (TLT). The rats in the stress groups were exposed sequentially to a variety of mild stressors for 8 weeks. Rats were weighed weekly. After 5 weeks of stressing, the Drug group received a daily injection of fluoxetine (10 mg/kg), and the TLT group was irradiated transcranially 3 times a week (810 nm wavelength laser, 3 mm diameter probe, 350 mW peak power, 100 Hz with 20% duty cycle, 2‐minute treatment time, 120 J/cm2 average energy density on skin surface). After 3 weeks of treatment, a forced swimming test (FST) was performed and recorded for behavioral assessment. Animals were euthanized after 8 weeks of the study.ResultsThe No‐stress group had significantly higher body weight than stress groups from week 5 (P < 0.05). No weight difference was found between the stress groups before treatment. However, the Drug group had significantly less body weight than both Stress and TLT groups after 2 weeks of treatment (P < 0.05). FST showed that the Stress group had significantly more immobility than the No‐stress group (P < 0.05). Both Drug and TLT groups had significantly less immobility than the stress group (P < 0.05). There was no significant difference in immobility between both Drug and TLT groups (P = 0.62).ConclusionsTLT was comparable to fluoxetine in improving the behavioral outcome after CMS. TLT did not cause weight loss, which is consistently seen in patients treated with fluoxetine. This study demonstrates that TLT has potential as an effective treatment for depression. Lasers Surg. Med. 44:227–232, 2012. © 2012 Wiley Periodicals, Inc.
Effect of glucose concentration during in vitro culture of mouse embryos on development to blastocyst, success of embryo transfer, and litter sex ratio
Authors: Bermejo‐Alvarez P. , Roberts R.M. , Rosenfeld C.S. 
Published: February 2012

AbstractA high‐glucose concentration in the reproductive tract during early development may result in aberrant embryo or fetal development, with effects that could have a greater impact on one sex than the other. Here, we determine if a high‐glucose concentration impacts embryo development and pregnancy outcomes in a sex‐specific manner in the mouse. Zygotes were cultured in potassium simple optimized medium, which typically contains 0.2 mM D‐glucose, with and without additional glucose supplementation to a concentration of 28 mM. Zygote cleavage and blastocyst rate did not differ between treatments, but total and trophectoderm cell counts were reduced in blastocysts cultured in a high glucose. No differences between sexes nor inner cell mass cell number were observed within each treatment. Blastocysts developed in both media were transferred to recipients. The percentage of blastocysts resulting in viable pups was significantly reduced when the blastocysts were cultured in 28 mM glucose (74 ± 4%, controls vs. 55.8 ± 7.1%, 28 mM glucose), but conceptus loss affected both sexes equally as litter sex ratio did not differ between treatments (52.7% and 52.2% males for controls and high glucose, respectively). Pup body weight at birth was higher for males than females, but was not affected by earlier culture in high glucose. In conclusion, in vitro culture in medium with a glucose concentration approximating that of diabetic serum reduces total and trophectoderm cell numbers at the blastocyst stage and conceptus development to term, but these detrimental effects are not sex‐specific. Mol. Reprod. Dev. 79: 329–336, 2012. © 2012 Wiley Periodicals, Inc.
Cloning the uteroglobin gene promoter from the relic volcano rabbit (Romerolagus diazi) reveals an ancient estrogen‐response element
Authors: Acosta‐MontesdeOca Adriana , Zariñán Teresa , Macías Héctor , Pérez‐Solís Marco A. , Ulloa‐Aguirre Alfredo , Gutiérrez‐Sagal Rubén 
Published: February 2012

AbstractTo gain further insight on the estrogen‐dependent transcriptional regulation of the uteroglobin (UG) gene, we cloned the 5′‐flanking region of the UG gene from the phylogenetically ancient volcano rabbit (Romerolagus diazi; Rd). The cloned region spans 812 base pairs (bp; −812/−1) and contains a noncanonical TATA box (TACA). The translation start site is 48 bp downstream from the putative transcription initiation site (AGA), and is preceded by a consensus Kozak box. Comparison of the Rd‐UG gene with that previously isolated from rabbits (Oryctolagus cuniculus) showed 93% in sequence identity as well as a number of conserved cis‐acting elements, including the estrogen‐response element (ERE; −265/−251), which differs from the consensus by two nucleotides. In MCF‐7 cells, 17β‐estradiol (E2) induced transcription of a luciferase reporter driven by the Rd‐UG promoter in a similar manner as in an equivalent rabbit UG reporter; the Rd‐UG promoter was 30% more responsive to E2 than the rabbit promoter. Mutagenesis studies on the Rd‐ERE confirmed this cis‐element as a target of E2 as two luciferase mutant reporters of the Rd‐promoter, one with the rabbit and the other with the consensus ERE, were more responsive to the hormone than the wild‐type reporter. Gel shift and super‐shift assays showed that estrogen receptor‐α indeed binds to the imperfect palindromic sequence of the Rd‐ERE. Mol. Reprod. Dev. 79: 337–345, 2012. © 2012 Wiley Periodicals, Inc.
Minimum‐time anti‐swing motion planning of cranes using linear programming
Authors: Da Cruz J.J. , Leonardi F. 
Published: February 2012

SUMMARYA novel method to solve the minimum‐time anti‐swing motion planning problem for cranes based on the use of linear programming is proposed. It is shown that its solution can be obtained by solving a sequence of fixed‐time maximum‐range linear programming problems. A convergence proof is presented. A classical kinematical model for which the trolley acceleration is the control variable is used. The crane motion equations are discretized in time assuming that the control variable is piecewise constant. Inequality constraints on both trolley speed and acceleration are included to represent physical bounds associated to the electromechanical driving system. The load and the trolley are required to be at rest both at the initial and at the final times. The load cable length as a function of time is assumed given. The ease of both the formulation and the solution of the problem is in contrast with the traditional two‐point boundary value problem associated to the Pontryagin's minimum principle. Copyright © 2012 John Wiley & Sons, Ltd.
A time‐varying coefficient‐based manipulability‐maximizing scheme for motion control of redundant robots subject to varying joint‐velocity limits
Authors: Zhang Yunong , Li Jun , Zhang Zhijun 
Published: February 2012

SUMMARYA time‐varying coefficient‐based manipulability‐maximizing (TVCMM) scheme subject to varying joint‐velocity limits (VJVL) is proposed and investigated in this paper for the optimal motion control of redundant robot manipulators (where a planar robot manipulator is specifically considered). In order to improve the manipulability during the end‐effector task execution, a manipulability‐maximizing index is considered into the scheme formulation. Besides, for the remedy of the nonzero initial/final joint‐velocity problem, a time‐varying coefficient is introduced and incorporated in the scheme, which is further reformulated as a quadratic program (QP) subject to equality and bound constraints. For guaranteeing the physical realizability of such a scheme, an efficient linear variational inequality‐based (LVI‐based) numerical algorithm is employed to solve such a QP, and an experiment based on a 6‐DOF manipulator is presented, of which the redundancy is on the horizontal plane. Simulative and experimental results validate the physical realization, effectiveness, and accuracy of the proposed QP‐based manipulability‐maximizing scheme. Copyright © 2012 John Wiley & Sons, Ltd.
Solution of linear optimal control problems with time delay using a composite Chebyshev finite difference method
Authors: Marzban H.R. , Hoseini S.M. 
Published: February 2012

SUMMARYIn this paper, a composite Chebyshev finite difference method is introduced and applied for finding the solution of optimal control of time‐delay systems with a quadratic performance index. This method is an extension of the Chebyshev finite difference scheme. The proposed method can be regarded as a nonuniform finite difference scheme and is based on a hybrid of block‐pulse functions and Chebyshev polynomials using the well‐known Chebyshev–Gauss–Lobatto points. Various types of time‐delay systems are included to demonstrate the validity and the applicability of the technique. The method is easy to implement and provides very accurate results. Copyright © 2012 John Wiley & Sons, Ltd.
Deposition of Fluorocarbon Nanoclusters by Gas Aggregation Cluster Source
Authors: Drábik Martin , Serov Anton , Kylián Ondřej , Choukourov Andrei , Artemenko Anna , Kousal Jaroslav , Polonskyi Oleksandr , Biederman Hynek 
Published: February 2012

AbstractGas aggregation cluster source based on planar magnetron was used for deposition of fluorocarbon nanocluster films. The films possess a high roughness with a size of nanoclusters estimated to be about 30 nm in average. Their chemical structure was found to resemble that of a conventional bulk polytetrafluoroethylene which was confirmed by X‐ray photoelectron spectroscopy and Fourier‐transform infrared spectroscopy. The fluorine to carbon elemental ratio was found to be 1.95 with 86% of CF2 structural units. The deposited films revealed super‐hydrophobic character with values of water contact angle reaching over 170°.magnified image
Exploration of the tree‐level S‐matrix of massless particles
Authors: Benincasa P. 
Published: February 2012

AbstractIn recent years, the BCFW construction provided a very powerful tool for computing scattering amplitudes as well as it shed light on the perturbation theory structure. In this talk, I discuss the long‐standing issue of the boundary term arising when the amplitudes do not vanish as some momenta are taken to infinity along some complex direction. In particular, we provide a new set of on‐shell recursion relations valid for such theories and discuss its consequences on our understanding on the perturbation theory structure of the S‐Matrix.
Characterization of low Al content AlxGa1−xN epitaxial films grown by atmospheric‐pressure MOVPE
Authors: Touré A. , Halidou I. , Benzarti Z. , Fouzri A. , Bchetnia A. , El Jani B. 
Published: February 2012

AbstractAlxGa1−xN epitaxial films grown on GaN/sapphire by atmospheric‐pressure metalorganic vapor phase epitaxy (AP‐MOVPE) using trimethylgallium (TMG) and trimethylaluminum (TMA) as group III precursors have been studied. Two groups of samples were grown. The aluminum (Al) solid composition of AlxGa1−xN was varied in the range from 0.03 to 0.20 by changing the molar flow ratio [TMA/(TMA + TMG)]. The effect of TMA flow rate, respectively, TMG flow rate, on the growth rate, and Al solid composition is discussed. The structural properties of the alloys have been investigated by high‐resolution X‐ray diffraction (HRXRD). The optical properties of these samples were investigated by photoluminescence (PL). It is found that on increasing Al solid composition, via an increase of the TMA flow rate, the structural quality is deteriorated and the growth efficiency decreases. On the other hand, when the TMG flow rate is reduced, a decrease of the full width at half‐maximum (FWHM) is observed with Al content.
A new dual‐material (DM) gate design to improve the subthreshold behavior of deep submicron GaN‐MESFETs
Authors: Lakhdar Nacereddine , Djeffal Fayçal , Dibi Zohir 
Published: February 2012

AbstractIn the present work, we present a new design called the Dual‐Material‐gate (DM) Gallium Nitride (GaN)‐MESFET to improve the immunity against short channel effects (SCEs). The analytical analysis includes the modeling of the channel potential, subthreshold swing, threshold voltage and Drain‐Induced Lowering Barrier (DIBL). The influence of gate length and the work function of each gate region on subthreshold behavior was investigated using the developed analytical models. The developed analytical approaches are verified and validated by the good agreement found with the 2D numerical simulations for wide range of device parameters and bias conditions. The proposed (DM) GaN‐MESFET can alleviate the critical problem and further improve the immunity of SCEs of deep submicron GaN‐MESFET‐based circuits for low power and high Frequency applications (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Real‐time studies of In‐adlayer during PAMBE of InGaN/GaN MQWs
Authors: Kim Tong‐Ho , Losurdo Maria , Choi Soojeong , Yoon Inho , Bruno Giovanni , Brown April 
Published: February 2012

AbstractThe control of In adlayer during plasma‐assisted molecular beam epitaxy (PAMBE) of InGaN/GaN multiquantum wells (MQWs) is critical to achieve good structural and optical properties. This contribution focuses on the investigation by real‐time spectroscopic ellipsometry, corroborated by reflection high energy electron diffraction (RHEED), of In adlayer during the PAMBE growth of InGaN/GaN MQWs. The ellipsometric data reveal In accumulation during InGaN growth, which results in thicker quantum well than designed. We address the effect of the indium adlayer on the growth of InGaN/GaN with an indium composition between 7% and 13%, and on their optical and structural properties determined by high‐resolution X‐ray diffraction and photoluminescence. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reduction of mechanical stresses in GaN/sapphire templates via formation of regular porous structure
Authors: Ivukin Ivan N. , Bougrov Vladislav E. , Odnoblyudov Maxim A. , Romanov Alexey E. 
Published: February 2012

AbstractReduction of mechanical stresses generated at a GaN/sapphire interface is an important issue on the way to more reliable and mechanically stable templates for manufacturing of efficient light‐emitting diodes. One of the techniques to reduce such stresses is the formation of the patterned porous structure in a GaN film in the vicinity of the GaN/sapphire interface by GaN overgrowth. The aim of the present study is to determine the effectiveness of the described method in reducing internal stresses and to find out the preferential configuration for the patterned structure. To achieve the aim, we performed a parametrical study of stresses in the structure, which consists of a porous GaN film and a sapphire substrate, by varying geometrical parameters of the pattern. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of In incorporation into the quantum well active region on the efficiency of AlGaN‐based ultraviolet light‐emitting diodes
Authors: Passow Thorsten , Gutt Richard , Kunzer Michael , Kirste Lutz , Pletschen Wilfried , Forghani Kamran , Scholz Ferdinand , Köhler Klaus , Wagner Joachim 
Published: February 2012

AbstractImproving the internal quantum efficiency is still a major challenge for realizing efficient III‐nitride‐based light‐emitting diodes (LEDs) with emission wavelengths below 365 nm. Here, we report on the influence of a very low In amount of less than 1% on the luminescence properties of single Ga(In)N/AlGaN quantum well (QW) structures and the performance of AlGaN‐based LEDs with an emission wavelength of about 350 nm. The samples were grown by metalorganic vapor phase epitaxy on low defect density AlGaN buffer layers on (0001) sapphire substrates. The temperature dependence of the QW emission energy reveals a clear “S‐shape” behaviour indicating a significant carrier localization for In containing QWs. The electroluminescence efficiency of LEDs with a GaInN QW active region could be improved by a factor of 4 compared to LEDs with GaN QW, resulting in a continuous wave (cw) output power of 8.2 mW at 40 mA. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
AFM Study for Morphological Characteristics and Biomechanical Properties of Human Cataract Anterior Lens Capsules
Authors: Choi Samjin , Lee Hui‐Jae , Cheong Youjin , Shin Jae‐Ho , Jin Kyung‐Hyun , Park Hun‐Kuk , Park Young‐Guk 
Published: February 2012

SummaryThe aim of this study was to quantitatively investigate the morphologies (surface roughness) and biomechanical properties (Young's modulus) of human anterior lens capsules (ALCs) for noncataract and cataract groups using atomic force microscopy. Eight human ALCs obtained during phacoemulsification from patients with senile cataracts (72 ± 13 years) were investigated in both the hydrated and dehydrated conditions. The cataract group showed clearly the proliferated lens epithelial cells (LECs) with a monomorphic cell structure, a diameter of 12.54 ± 4.31 μm, and a height of 0.23 ± 0.04 μm, whereas the control group showed no LECs. A substantial amount of false‐positive calcification was observed caused by the deposition of remnants of dried salt solution. Cataract group showed significantly higher surface roughness (382.06 nm, p ≤ 0.001) than control group in the anterior side of ALCs, whereas cataract group showed significantly lower surface roughness (353.79 nm, p ≤ 0.001) than control group in their posterior side. Cataract group showed significantly higher Young's modulus (69.52 kPa, p ≤ 0.001) compared to the control group, regardless of the ALC side. Therefore, it is significant that this study provides a new method to examine the nanostructural characteristic and biomechanical property of human ALCs through a nanometer‐scale resolution microscopy technique. SCANNING 34: 247‐256, 2012. © 2012 Wiley Periodicals, Inc.
Lost in translation: Cultural codes are not blueprints
Authors: Aldrich Howard E. , Yang Tiantian 
Published: February 2012

AbstractEntrepreneurship enjoys widespread appeal in nearly all capitalist nations, but start‐up success has proved elusive for most entrepreneurs. We explain the low likelihood of entrepreneurial success by focusing on the contrast between organizational forms in terms of cultural codes that tap into widely held perceptions versus organizational forms in terms of blueprints that sustain effective guidance for organizational activities. The dilemma facing nascent entrepreneurs during their life course is the incomplete and fragmentary nature of these opportunities for learning about start‐up practices. We conclude the article by offering suggestions for further research to discover what entrepreneurs actually do during the start‐up process. Copyright © 2012 Strategic Management Society.
Intracellular Protein Delivery and Gene Transfection by Electroporation Using a Microneedle Electrode Array
Authors: Choi Seong‐O , Kim Yeu‐Chun , Lee Jeong Woo , Park Jung‐Hwan , Prausnitz Mark R. , Allen Mark G. 
Published: February 2012

AbstractThe impact of many biopharmaceuticals, including protein‐ and gene‐based therapies, has been limited by the need for better methods of delivery into cells within tissues. Here, intracellular delivery of molecules and transfection with plasmid DNA by electroporation is presented using a novel microneedle electrode array designed for the targeted treatment of skin and other tissue surfaces. The microneedle array is molded out of polylactic acid. Electrodes and circuitry required for electroporation are applied to the microneedle array surface by a new metal‐transfer micromolding method. The microneedle array maintains mechanical integrity after insertion into pig cadaver skin and is able to electroporate human prostate cancer cells in vitro. Quantitative measurements show that increasing electroporation pulse voltage increases uptake efficiency of calcein and bovine serum albumin, whereas increasing pulse length has lesser effects over the range studied. Uptake of molecules by up to 50% of cells and transfection of 12% of cells with a gene for green fluorescent protein is demonstrated at high cell viability. It is concluded that the microneedle electrode array is able to electroporate cells, resulting in intracellular uptake of molecules, and has potential applications to improve intracellular delivery of proteins, DNA, and other biopharmaceuticals.