bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical Property and Long-Term Stability of Transparent Capacitors Using Multi-Layer Transparent Conducting Oxide Electrodes
Authors: Xian Cheng-Ji , Park Jong-Man , Jung Hyun-June , Yoon Soon-Gil
Published: March 2011

Transparent capacitors of Al0.016In0.003Zn0.981O (AIZO)/Ag/AIZO/Bi2Mg2/3Nb4/3O7 (BMN)/AIZO/glass were prepared using BMN films with various thicknesses grown on AIZO/glass (Corning 1737) substrates by pulsed laser deposition. The BMN films deposited at 150 °C on the AIZO electrode exhibited a dielectric constant of 49–55, a dielectric loss of 3–7% at the frequency of 100 kHz and the leakage current densities of ∼10-8 A/cm2 at 200 kV/cm, in the range of the thickness from 50 to 200 nm. After damp heat treatment for 300 h under the condition of 85% relative humidity at 85 °C, the electrical properties in the BMN capacitors were slightly degraded. The AIZO/Ag/AIZO/BMN/AIZO capacitors maintained the optical transmittance of approximately 77% at a wavelength of 500 nm after damp heat treatment.
Fabrication and Evaluation of Nanopillar-Shaped Phase-Change Memory Devices
Authors: Hong Sung-Hoon , Shin Ju-Hyeon , Bae Byeong-Ju , Lee Heon
Published: March 2011

In this study, nanopillar-shaped phase-change memory devices of various sizes were simply fabricated by nanosphere lithography, and their electrical characteristics were evaluated by conductive atomic force microscopy (AFM). As nanosphere materials, 180-nm diameter polystyrene balls were used for a size-controllable mask, silica balls with a diameter of 200 nm for a high etching-resistance mask, and sub-50 nm Ag nanoparticles were used for sub-50-nm-scale fabrication. Using the polystyrene balls, silica balls, and Ag nanoparticles, nanopillar-shaped phase-change memory devices with various diameters, heights as large as 1 µm, and sizes as small as less than 50 nm were successfully fabricated. The electrical properties of the nanopillar-shaped Ge2Sb2Te5devices were evaluated by conductive AFM with an electrical measurement system.
Oxidization Characteristics of Standard Platinum Resistance Thermometers
Authors: Sakurai Hirohisa , Tamura Osamu
Published: March 2011

The oxidization characteristics of a standard platinum resistance thermometer are discussed. A platinum sensing wire is oxidized by oxygen in a thermometer sheath, such as PtO2 or PtO, depending on temperature below 500 °C. The platinum oxide PtO2 is confirmed to be formed spontaneously in the sensing wire in a temperature range below 300 °C. In this temperature range, the area of the platinum oxide below the surface of the sensing wire is divided into two parts, i.e., the PtO2 area near the surface and the PtO area below it, the boundary of which depends on the diffusion depth of oxygen. The platinum oxide PtO is also confirmed to be spontaneously formed from Pt above 300 °C, after a certain amount of PtO is formed in the sensing wire with the help of PtO2.
Observation of Defects that Reduce Schottky Barrier Height in 4H-SiC Schottky Contacts Using Electrochemical Deposition of ZnO
Authors: Kato Masashi , Ono Hidenori , Ichimura Masaya , Feng Gan , Kimoto Tsunenobu
Published: March 2011

We performed the electrochemical deposition of ZnO on 4H-SiC epilayers and characterized Schottky diodes fabricated on the same epilayers in order to find the positions of defects that cause the low Schottky barrier height. We found that the positions where ZnO was deposited corresponded to the positions of contacts with lower Schottky barrier heights than the other contacts. After the removal of the ZnO layer, the surfaces of the ZnO-deposited positions were observed by atomic force microscopy. Photoluminescence mapping was also performed to observe the distribution of stacking faults. Then, the epilayer was etched using molten salt and the resulting etch pits were observed. Finally, we discussed the types of defects that reduce the Schottky barrier height.
Magnetic Tweezers with Magnetic Thin Films
Authors: Hsieh Yi-Ping , Wei Zung-Hang
Published: March 2011

Magnetic tweezers consisting of a 75×0.65×0.3 µm3 silicon oxide cantilever and a 72×13×0.3 µm3 silicon oxide plate deposited with magnetic thin films are fabricated and placed under various magnetic fields to observe their flexure. The principle of the magnetic tweezers is magnetic torque on condition that the high shape magnetic anisotropy is designed and a highly sensitive microcantilever is fabricated. When the magnetic tweezers are placed under a horizontal magnetic field, they will close under a large magnetic field; when the magnetic tweezers are placed under a vertical magnetic field, they will open under a large magnetic field. On the other hand, the directions of magnetic field can control the distance between the magnetic tweezers. Therefore, magnetic tweezers can be expected as magnetic components in microelectromechanical systems (MEMS) and applied to grabbing cells in biotechniques.
All-Inkjet-Printed Organic Thin-Film Transistors with Silver Gate, Source/Drain Electrodes
Authors: Chung Seungjun , Jang Jongsu , Cho Junhee , Lee Changhee , Kwon Soon-Ki , Hong Yongtaek
Published: March 2011

We report high-performance all-inkjet-printed organic thin-film transistors (OTFTs), where inkjet-printed silver electrodes, cross-linked poly(4-vinylphenol) (PVP) and 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) were used as gate/source/drain electrodes, a gate dielectric layer and an active semiconductor layer, respectively. To evaluate quality of the active semiconductor layer, we also fabricated OTFTs by using spin-coating and drop-casting methods for TIPS-pentacene layer on the inkjet-printed PVP gate dielectric layer. Comparable TFT electrical performances were obtained and well-crystallized TIPS-pentacene layer was formed for all cases. All TIPS-pentacene OTFTs show lower sub-threshold swing values than OTFTs with an evaporated pentacene active semiconductor layer on the inkjet-printed PVP gate dielectric layer. By using optimized inkjet-printing conditions, we obtained mobility of 0.06 cm2 V-1 s-1 and on/off ratio of 104 for all-inkjet-printed OTFT.
Inverters Using Only N-Type Indium Gallium Zinc Oxide Thin Film Transistors for Flat Panel Display Applications
Authors: Hwang Tong-Hun , Yang Ik-Seok , Kwon Oh-Kyong , Ryu Min-Ki , Byun Choon-Won , Hwang Chi-Sun , Park Sang-Hee Ko
Published: March 2011

Two inverter architectures are proposed to be integrated on panels for flat panel display applications using only n-type amorphous indium gallium zinc oxide (IGZO) thin film transistors (TFTs). The proposed cross-coupled (CC) inverter uses the positive feedback effect of its CC structure to reduce the static current and increase the output voltage swing when using depletion mode n-type amorphous IGZO TFTs. The other proposed cross-coupled and bootstrapping (CCB) inverter also uses the cross-coupled structure and includes a capacitor for the bootstrapping effect to increase the operating frequency. The measured results show that the output voltage swing of the proposed CC inverter is from 0 to 14.50 V and that of the CCB inverter is from 0.15 to 14.57 V when V
DD is 15 V at 20 kHz and the load capacitance is 103.0 pF. The power consumption of the CC and CCB inverters are 1.4 and 2.5 mW, respectively, which are 29.3 and 53.4% of the power consumption of the ratioed inverter.
Employ Present Five Masks Amorphous Silicon Thin-Film Transistor Design and Process Flow to Realize 5-in. InGaZnO Active-Matrix Liquid Crystal Display with Improved Stress Stability
Authors: Hung Ming-Chin , Hsiao Hsia-Tsai , Lin Wei-Ting , Tu Chun-Hao , Chang Jiun-Jye , Chen Po-Lun
Published: March 2011

The present five masks bottom gate and staggered amorphous silicon (a-Si) thin-film transistor (TFT) process flow is not suitable for indium–gallium–zinc-oxide (IGZO) TFT because of its vulnerability to post etching process during the source/drain pattern. Bottom gate and coplanar IGZO TFTs were made feasible through the reverse of second (channel layer) and third (source/drain electrodes) masks process flow to avoid etching damage problem. Besides, the post IGZO nitrous oxygen (N2O) plasma treatment was employed to improve the stress instability. On the basis of secondary ion mass spectrometry (SIMS) and X-ray spectroscopy (XPS) results, it is believed that the post N2O plasma treatment passivates the interface states and converts the inhomogeneous and low quality IGZO to the homogeneous and high quality IGZO. In the end, a 5-in. IGZO active-matrix liquid crystal display was demonstrated via five masks bottom gate and coplanar TFT configuration.
Light Response of Top Gate InGaZnO Thin Film Transistor
Authors: Park Sang-Hee Ko , Ryu Minki , Yoon Sung Min , Yang Shinhyuk , Hwang Chi-Sun , Jeon Jae-Hong , Kim Kyounghwan
Published: March 2011

The light stability of top gate indium gallium zinc oxide (IGZO) thin film transistor (TFT) has been investigated under gate bias and constant current stress to explore the possibility of active matrix display applications. While the halogen lamp irradiation onto the device under positive gate bias stress caused just -0.18 V of threshold voltage shift (ΔV
th), it resulted in -15.1 V shift under negative gate bias stress. When the white light extracted from the halogen lamp of 100 µW/cm2 power illuminated the device under constant current stress, operation voltage shifted just -0.05 V for 21 h. The result shows good promise for the application of highly stable IGZO TFT to active matrix organic light emitting diodes (AMOLEDs).
Decoder-Type Gate Driver Circuits Fabricated with Amorphous Silicon Thin-Film Transistors for Active Matrix Displays
Authors: Kim Tae-Wook , Park Gyu-Tae , Choi Byong-Deok , Hong MunPyo , Jang Jin-Nyoung , Song Byoung-Cheol , Lee Dong Hyeok , Bae Byung Seong
Published: March 2011

This paper quantitatively analyzes the signal integrity and device stability issues of gate driver circuits for active matrix displays integrated with hydrogenated amorphous silicon thin-film transistors (a-Si:H TFTs), and reveals that the clock-coupling noises and threshold voltage shift due to the DC gate bias in previous gate driver circuits can seriously affect the image quality. To resolve these problems, two types of decoder-based gate driver circuits have been proposed, that can completely avoid the floating output node to prevent the clock-coupling noises without applying the DC gate bias to all the TFTs used in the gate driver circuits. The performances and characteristics of the two proposed types of gate drivers will be discussed and compared, and the experimental results for the fabricated circuits will be presented.
Design and Implementation of Readout Circuit with Threshold Voltage Compensation on Glass Substrate for Touch Panel Applications
Authors: Lin Yu-Ta , Ker Ming-Dou , Wang Tzu-Ming
Published: March 2011

A new on-panel readout circuit with threshold voltage compensation for capacitive sensor in low temperature polycrystalline silicon (poly-Si) thin-film transistor (LTPS-TFT) process has been proposed. In order to compensate the threshold voltage variation from LTPS process variation, the proposed readout circuit applies a novel compensation approach with switch capacitor technique. In addition, a 4-bit analog-to-digital converter (ADC) is added to identify different sensed capacitor values and further enhances the overall resolution of touch panel.
Competitive analysis of flash memory algorithms
Authors: Ben-Aroya Avraham , Toledo Sivan
Published: March 2011

Flash memories are widely used in computer systems ranging from embedded systems to workstations and servers to digital cameras and mobile phones. The memory cells of flash devices can only endure a limited number of write cycles, usually between 10,000 and 1,000,000. Furthermore, cells containing data must be
erased
before they can store new data, and erasure operations erase large blocks of memory, not individual cells. To maximize the endurance of the device (the amount of useful data that can be written to it before one of its cells wears out), flash-based systems move data around in an attempt to reduce the total number of erasures and to level the wear of the different erase blocks. This data movement introduces an interesting online problem called the
wear-leveling problem
. Wear-leveling algorithms have been used at least since 1993, but they have never been mathematically analyzed. In this article we analyze the two main wear-leveling problems. We show that a simple randomized algorithm for one of them is essentially optimal both in the competitive sense and in the absolute sense (our competitive result relies on an analysis of a nearly-optimal offline algorithm). We show that deterministic algorithms cannot achieve comparable endurance. We also analyze a more difficult problem and show that offline algorithms for it can improve upon naive approaches, but that online algorithms essentially cannot.
Aging and estrogen alter endothelial reactivity to reactive oxygen species in coronary arterioles
Authors: Kang Lori S. , Chen Bei , Reyes Rafael A. , LeBlanc Amanda J. , Teng Bunyen , Mustafa S. Jamal , Muller-Delp Judy M.
Published: March 2011

Endothelium-dependent, nitric oxide (NO)-mediated vasodilation can be impaired by reactive oxygen species (ROS), and this deleterious effect of ROS on NO availability may increase with aging. Endothelial function declines rapidly after menopause, possibly because of loss of circulating estrogen and its antioxidant effects. The purpose of the current study was to determine the role of O2−and H2O2in regulating flow-induced dilation in coronary arterioles of young (6-mo) and aged (24-mo) intact, ovariectomized (OVX), or OVX + estrogen-treated (OVE) female Fischer 344 rats. Both aging and OVX reduced flow-induced NO production, whereas flow-induced H2O2production was not altered by age or estrogen status. Flow-induced vasodilation was evaluated before and after treatment with the superoxide dismutase (SOD) mimetic Tempol (100 μM) or the H2O2scavenger catalase (100 U/ml). Removal of H2O2with catalase reduced flow-induced dilation in all groups, whereas Tempol diminished vasodilation in intact and OVE, but not OVX, rats. Immunoblot analysis revealed elevated nitrotyrosine with aging and OVX. In young rats, OVX reduced SOD protein while OVE increased SOD in aged rats; catalase protein did not differ in any group. Collectively, these studies suggest that O2−and H2O2are critical components of flow-induced vasodilation in coronary arterioles from female rats; however, a chronic deficiency of O2−buffering by SOD contributes to impaired flow-induced dilation with aging and loss of estrogen. Furthermore, these data indicate that estrogen replacement restores O2−homeostasis and flow-induced dilation of coronary arterioles, even at an advanced age.
Left ventricular strain, rotation, and torsion as markers of acute myocardial ischemia
Authors: Moen Christian Arvei , Salminen Pirjo-Riitta , Grong Ketil , Matre Knut
Published: March 2011

This study investigates how tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE) describe regional myocardial deformation during controlled reductions of left anterior descending (LAD) coronary artery perfusion pressure. In eight anesthetized pigs, a shunt with constrictor was installed from the brachiocephalic artery to the LAD. Data were obtained with open shunt, followed by four degrees of stenosis (S1-S4) of increasing severity: S1, ∼15%; S2, ∼35%; S3, ∼50%; and S4, ∼60% reductions of LAD perfusion pressure. At each situation, microspheres for perfusion measurements were injected and left ventricular (LV) short- and long-axis cineloops were recorded. In the anterior wall, radial, circumferential, and longitudinal one-layer STE strain, one-layer radial TDI strain, and three-layer radial TDI and STE strain were measured. LV peak mean rotation was measured at six equidistant levels from apex to base (in 7 pigs). LV torsion was calculated from end-systolic mean rotation. With open shunt, three-layer TDI analysis showed a transmural strain gradient with no perfusion gradient. Perfusion, one-layer TDI strain, and strain in the mid- and subendocardium from three-layer TDI were reduced at S2 ( P < 0.05). STE strain was not affected until S3 ( P < 0.05). Peak mean rotation, increasing toward the apex, decreased at the three apical levels at S4 ( P < 0.05). LV torsion did not decrease ( P = 0.26). In conclusion, TDI strain detected dysfunction already with minor changes in global hemodynamics, whereas STE strain was first reduced with moderate changes. LV peak mean rotation was not reduced until severe reduction of LAD perfusion pressure, but remained increasingly counterclockwise toward the apex. LV torsion remained unaffected by ischemia.
Modulated dispersion of activation and repolarization by premature beats in patients with cardiomyopathy at risk of sudden death
Authors: Subramanian Anandaraja , Suszko Adrian , Selvaraj Raja J. , Nanthakumar Kumaraswamy , Ivanov Joan , Chauhan Vijay S.
Published: March 2011

Premature beats can trigger ventricular arrhythmias in heart disease, but the mechanisms are not well defined. We studied the effect of premature beats on activation and repolarization dispersion in seven patients with cardiomyopathy (57 ± 10 yr, left ventricular ejection fraction 31 ± 7%). Activation time (AT), activation-recovery interval (ARI), and total repolarization time (TRT) were measured from 26 unipolar electrograms during right ventricle (RV) endocardial (early) to left ventricle epicardial (late) activation in response to RV apical extrastimulation (S1S2). Early TRT dispersion increased significantly with shorter S1S2 (1.0 ± 0.2 to 2.3 ± 0.4 ms/mm, P < 0.0001), with minimal change in late TRT dispersion (0.8 ± 0.1 to 1.0 ± 0.3 ms, P = 0.02). This was associated with an increase in early AT dispersion (1.0 ± 0.1 to 1.5 ± 0.2 ms/mm, P = 0.05) but no change in late AT dispersion (0.6 ± 0.1 to 0.7 ± 0.2 ms/mm, P = 0.4). Early and late ARI dispersion did not change with shorter S1S2. AT restitution slopes were similar between early and late sites, as was slope heterogeneity. ARI restitution slope was greater in early vs. late sites (1.3 ± 0.6 vs. 0.8 ± 0.6, P = 0.03), but slope heterogeneity was similar. With shorter S1S2, AT-ARI slopes became less negative (flattened) at both early (−0.4 ± 0.1 to +0.04 ± 0.2) and late (−1.5 ± 0.2 to +0.3 ± 0.2) sites, implying less activation-repolarization coupling. There was no difference in AT-ARI slopes between early and late sites at short S1S2. In conclusion, high-risk patients with cardiomyopathy have greater TRT dispersion at tightly coupled S1S2 due to greater AT dispersion and activation-repolarization uncoupling. Modulated dispersion is more pronounced at early vs. late activated sites, which may predispose to reentrant ventricular arrhythmias.
Enhancement of Na/K pump activity by chronic intermittent hypobaric hypoxia protected against reperfusion injury
Authors: Guo Hui-cai , Guo Fang , Zhang Li-Nan , Zhang Rong , Chen Qing , Li Jun-Xia , Yin Jian , Wang Yong-li
Published: March 2011

Chronic intermittent hypobaric hypoxia (CIHH) has been shown to attenuate intracellular Na+ accumulation and Ca2+ overload during ischemia and reperfusion (I/R), both of which are closely related to the outcome of myocardial damage. Na/K pump plays an essential role in maintaining the equilibrium of intracellular Na+ and Ca2+ during I/R. It has been shown that enhancement of Na/K pump activity by ischemic preconditioning may be involved in the cardiac protection. Therefore, we tested whether Na/K pump was involved in the cardioprotection by CIHH. We found that Na/K pump current in cardiac myocytes of guinea pigs exposed to CIHH increased 1.45-fold. The K 1 and f 1, which reflect the portion of α1-isoform of Na/K pump, dramatically decreased or increased, respectively, in CIHH myocytes. Western blot analysis revealed that CIHH increased the protein expression of the α1-isoform by 76%, whereas the protein expression of the α2-isoform was not changed significantly. Na/K pump current was significantly suppressed in simulated I/R, and CIHH preserved the Na/K pump current. CIHH significantly improved the recovery of cell length and contraction during reperfusion. Furthermore, inhibition of Na/K pump by ouabain attenuated the protective effect afforded by CIHH. Collectively, these data suggest that the increase of Na/K pump activity following CIHH is due to the upregulating α1-isoform of Na/K pump, which may be one of the mechanisms of CIHH against I/R-induced injury.
Renal protective effect of chronic inhibition of COX-2 with SC-58236 in streptozotocin-diabetic rats
Authors: Quilley J. , Santos M. , Pedraza P.
Published: March 2011

The induction of renal cyclooxygenase-2 (COX-2) in diabetes has been implicated in the renal functional and structural changes in models where hypertension or uninephrectomy was superimposed. We examined the protective effects of 3 mo treatment of streptozotocin-diabetic rats with a highly selective COX-2 inhibitor (SC-58236) in terms of albuminuria, renal hypertrophy, and the excretion of TNF-α and TGF-β, which have also been implicated in the detrimental renal effects of diabetes. SC-58236 treatment (3 mg·kg−1·day−1) of diabetic rats resulted in reduced urinary excretion of PGE2, 6-ketoPGF1α, and thromboxane B2, all of which were increased in the diabetic rat compared with age-matched nondiabetic rats. However, serum thromboxane B2 levels were unchanged, confirming the selectivity of SC-58236 for COX-2. The renal protective effects of treatment of diabetic rats with the COX-2 inhibitor were reflected by a marked reduction in albuminuria, a reduction in kidney weight-to-body weight ratio, and TGF-β excretion and a marked decrease in the urinary excretion of TNF-α. The protective effects of SC-58236 were independent of changes in plasma glucose levels or serum advanced glycation end-product levels, which were not different from those of untreated diabetic rats. In an additional study, the inhibition of COX-2 with SC-58236 for 4 wk in diabetic rats resulted in creatinine clearance rates not different from those of control rats. These results confirm that the inhibition of COX-2 in the streptozotocin-diabetic rat confers renal protection and suggest that the induction of COX-2 precedes the increases in cytokines, TNF-α, and TGF-β.
TGFβ signaling in lung epithelium regulates bleomycin-induced alveolar injury and fibroblast recruitment
Authors: Degryse Amber L. , Tanjore Harikrishna , Xu Xiaochuan C. , Polosukhin Vasiliy V. , Jones Brittany R. , Boomershine Chad S. , Ortiz Camila , Sherrill Taylor P. , McMahon Frank B. , Gleaves Linda A. , Blackwell Timothy S. , Lawson William E.
Published: March 2011

The response of alveolar epithelial cells (AECs) to lung injury plays a central role in the pathogenesis of pulmonary fibrosis, but the mechanisms by which AECs regulate fibrotic processes are not well defined. We aimed to elucidate how transforming growth factor-β (TGFβ) signaling in lung epithelium impacts lung fibrosis in the intratracheal bleomycin model. Mice with selective deficiency of TGFβ receptor 2 (TGFβR2) in lung epithelium were generated and crossed to cell fate reporter mice that express β-galactosidase (β-gal) in cells of lung epithelial lineage. Mice were given intratracheal bleomycin (0.08 U), and the following parameters were assessed: AEC death by terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling assay, inflammation by total and differential cell counts from bronchoalveolar lavage, fibrosis by scoring of trichrome-stained lung sections, and total lung collagen content. Mice with lung epithelial deficiency of TGFβR2 had improved AEC survival, despite greater lung inflammation, after bleomycin administration. At 3 wk after bleomycin administration, mice with epithelial TGFβR2 deficiency showed a significantly attenuated fibrotic response in the lungs, as determined by semiquantitatve scoring and total collagen content. The reduction in lung fibrosis in these mice was associated with a marked decrease in the lung fibroblast population, both total lung fibroblasts and epithelial-to-mesenchymal transition-derived (S100A4+/β-gal+) fibroblasts. Attenuation of TGFβ signaling in lung epithelium provides protection from bleomycin-induced fibrosis, indicating a critical role for the epithelium in transducing the profibrotic effects of this cytokine.
Simvastatin regulates CXC chemokine formation in streptococcal M1 protein-induced neutrophil infiltration in the lung
Authors: Zhang Songen , Rahman Milladur , Zhang Su , Qi Zhongquan , Herwald Heiko , Thorlacius Henrik
Published: March 2011

Streptococcus pyogenes of the M1 serotype can cause streptococcal toxic shock syndrome and acute lung injury. Statins exert beneficial effects in septic patients although the mechanisms remain elusive. This study examined effects of simvastatin on M1 protein-provoked pulmonary inflammation and tissue injury. Male C57BL/6 mice were pretreated with simvastatin or a CXCR2 antagonist before M1 protein challenge. Bronchoalveolar fluid and lung tissue were harvested for determination of neutrophil infiltration, formation of edema, and CXC chemokines. Flow cytometry was used to determine Mac-1 expression on neutrophils. Gene expression of CXC chemokines was determined in alveolar macrophages by using quantitative RT-PCR. M1 protein challenge caused massive infiltration of neutrophils, edema formation, and production of CXC chemokines in the lung as well as upregulation of Mac-1 on circulating neutrophils. Simvastatin reduced M1 protein-induced infiltration of neutrophils and edema in the lung. In addition, M1 protein-induced Mac-1 expression on neutrophils was abolished by simvastatin. Furthermore, simvastatin markedly decreased pulmonary formation of CXC chemokines and gene expression of CXC chemokines in alveolar macrophages. Moreover, the CXCR2 antagonist reduced M1 protein-induced neutrophil expression of Mac-1 and accumulation of neutrophils as well as edema formation in the lung. These novel findings indicate that simvastatin is a powerful inhibitor of neutrophil infiltration in acute lung damage triggered by streptococcal M1 protein. The inhibitory effect of simvastatin on M1 protein-induced neutrophil recruitment appears related to reduced pulmonary generation of CXC chemokines. Thus, simvastatin may be a useful tool to ameliorate acute lung injury in streptococcal infections.
Focusing Polycapillary Optics and Their Applications
Authors: MacDonald Carolyn A.
Published: March 2011

A summary of focusing X ray polycapillary optics is presented including history, theory, modeling, and applications development. The focusing effects of polycapillary optics come from the overlap of the beams from thousands of small hollow glass tubes. Modeling efforts accurately describe optics performance to allow for system development in a wide variety of geometries. The focusing of X ray beams with polycapillary optics yields high gains in intensity and increased spatial resolution for a variety of clinical, lab-based, synchrotron or in situ analysis applications.
Interventional Radiology and the Care of the Oncology Patient
Authors: O'Neill Siobhan B. , O'Connor Owen J. , Ryan Max F. , Maher Michael M.
Published: March 2011

Interventional Radiology (IR) is occupying an increasingly prominent role in the care of patients with cancer, with involvement from initial diagnosis, right through to minimally invasive treatment of the malignancy and its complications. Adequate diagnostic samples can be obtained under image guidance by percutaneous biopsy and needle aspiration in an accurate and minimally invasive manner. IR techniques may be used to place central venous access devices with well-established safety and efficacy. Therapeutic applications of IR in the oncology patient include local tumour treatments such as transarterial chemo-embolisation and radiofrequency ablation, as well as management of complications of malignancy such as pain, organ obstruction, and venous thrombosis.
Computing Exponential for Iterative Splitting Methods: Algorithms and Applications
Authors: Geiser Jürgen
Published: March 2011

Iterative splitting methods have a huge amount to compute matrix exponential. Here, the
acceleration and recovering of higher‐order schemes can be achieved. From a theoretical point of
view, iterative splitting methods are at least alternating Picards fix‐point iteration schemes.
For practical applications, it is important to compute very fast matrix exponentials. In this
paper, we concentrate on developing fast algorithms to solve the iterative splitting scheme.
First, we reformulate the iterative splitting scheme into an integral notation of matrix exponential.
In this notation, we consider fast approximation schemes to the integral formulations,
also known as ϕ‐functions. Second, the error analysis is explained and applied to the integral
formulations. The novelty is to compute cheaply the decoupled exp‐matrices and apply only
cheap matrix‐vector multiplications for the higher‐order terms. In general, we discuss an elegant way of embedding recently survey on methods for computing
matrix exponential with respect to iterative splitting schemes.
We present numerical benchmark examples, that compared standard splitting schemes
with the higher‐order iterative schemes. A real‐life application in contaminant transport as a
two phase model is discussed and the fast computations of the operator splitting method is
explained.
Existence and Iteration of Monotone Positive Solution of BVP for an Elastic Beam Equation
Authors: Sun Jian-Ping , Wang Xian-Qiang
Published: March 2011

This paper is concerned with the existence of monotone positive solution of boundary value problem for
an elastic beam equation. By applying iterative techniques, we not only obtain the existence of monotone
positive solution but also establish iterative scheme for approximating the solution. It is worth mentioning
that the iterative scheme starts off with zero function, which is very useful and feasible for computational
purpose. An example is also included to illustrate the main results.
High-Throughput Screen Identifies Novel Inhibitors of Cancer Biomarker α-Methylacyl Coenzyme A Racemase (AMACR/P504S)
Authors: Wilson Brice A.P. , Wang Haofan , Nacev Benjamin A. , Mease Ronnie C. , Liu Jun O. , Pomper Martin G. , Isaacs William B.
Published: March 2011

α-methylacyl coenzyme A racemase (AMACR) is a metabolic enzyme whose overexpression has been shown to be a diagnostic indicator of prostatic adenocarcinoma and other solid tumors. Here, we confirm that attenuation of AMACR expression diminishes the growth of prostate cancer cell lines by using stably expressed short-hairpin RNA constructs. This observation strongly suggests that the AMACR enzyme may be a target for therapeutic inhibition in prostate cancer. To this end, we report here a novel assay capable of screening libraries of diverse small molecules for inhibitors of AMACR activity. This assay facilitated the screening of approximately 5,000 unique compounds and the discovery of 7 distinct chemical entities capable of inhibiting AMACR at low micromolar concentrations. The most potent inhibitor discovered is the seleno-organic compound ebselen oxide [inhibitory concentration (IC50): 0.80 μmol/L]. The parent compound, ebselen (IC50: 2.79 μmol/L), is a covalent inactivator of AMACR (KI(inact): 24 μmol/L). Two of the AMACR inhibitors are selectively toxic to prostate cancer cell lines (LAPC4/LNCaP/PC3) that express AMACR compared to a normal prostate fibroblast cell line (WPMY1) that does not express the protein. This report shows the first high-throughput screen for the discovery of novel AMACR inhibitors, characterizes the first nonsubstrate-based inhibitors, and validates that AMACR is a viable chemotherapeutic target in vitro. Mol Cancer Ther; 10(5); 825–38. ©2011 AACR.
Caspase-3–Dependent Mitotic Checkpoint Inactivation by the Small-Molecule Inducers of Mitotic Slippage SU6656 and Geraldol
Authors: Riffell Jenna L. , Jänicke Reiner U. , Roberge Michel
Published: March 2011

Microtubule-targeting cancer drugs such as paclitaxel block cell-cycle progression at mitosis by prolonged activation of the mitotic checkpoint. Cells can spontaneously escape mitotic arrest and enter interphase without chromosome segregation by a process termed mitotic slippage that involves the degradation of cyclin B1 without mitotic checkpoint inactivation. Inducing mitotic slippage with chemicals causes cells to die after multiple rounds of DNA replication without cell division, which may enhance the antitumor activity of microtubule-targeting drugs. Here, we explore pathways leading to mitotic slippage by using SU6656 and geraldol, two recently identified chemical inducers of mitotic slippage. Mitotic slippage induced by SU6656 or geraldol was blocked by the proteasome inhibitor MG-132 and involved proteasome-dependent degradation of cyclin B1 and the mitotic checkpoint proteins budding uninhibited by benzimidazole related 1 (BubR1) and cell division cycle 20 (Cdc20) in T98G cells. Mitotic slippage and the degradation of BubR1 and Cdc20 were also inhibited by the caspase-3 and -7 inhibitor DEVD-CHO. MCF-7 cells lacking caspase-3 expression could not degrade BubR1 or undergo mitotic slippage in response to SU6656 or geraldol. Introduction of caspase-3 completely restored the ability of MCF-7 cells to degrade BubR1 and undergo mitotic slippage. However, lack of expression of caspase-3 did not affect cell death after exposure to paclitaxel, with or without mitotic slippage induction. The requirement for caspase-3 for chemically induced mitotic slippage reveals a new mechanism for mitotic exit and a link between mitosis and apoptosis that has implications for the outcome of cancer chemotherapy. Mol Cancer Ther; 10(5); 839–49. ©2011 AACR.
Assessing the Activity of Cediranib, a VEGFR-2/3 Tyrosine Kinase Inhibitor, against VEGFR-1 and Members of the Structurally Related PDGFR Family
Authors: Brave Sandra R. , Ratcliffe Kirsty , Wilson Zena , James Neil H. , Ashton Sue , Wainwright Anna , Kendrew Jane , Dudley Philippa , Broadbent Nicola , Sproat Graham , Taylor Sian , Barnes Claire , Silva Jeffrey C. , Farnsworth Charles L. , Hennequin Laurent , Ogilvie Donald J. , Jürgensmeier Juliane M. , Shibuya Masabumi , Wedge Stephen R. , Barry Simon T.
Published: March 2011

Cediranib is a potent inhibitor of the VEGF receptor (VEGFR)-2 and VEGFR-3 tyrosine kinases. This study assessed the activity of cediranib against the VEGFR-1 tyrosine kinase and the platelet-derived growth factor receptor (PDGFR)-associated kinases c-Kit, PDGFR-α, and PDGFR-β. Cediranib inhibited VEGF-A–stimulated VEGFR-1 activation in AG1-G1-Flt1 cells (IC50 = 1.2 nmol/L). VEGF-A induced greatest phosphorylation of VEGFR-1 at tyrosine residues Y1048 and Y1053; this was reversed by cediranib. Potency against VEGFR-1 was comparable with that previously observed versus VEGFR-2 and VEGFR-3. Cediranib also showed significant activity against wild-type c-Kit in cellular phosphorylation assays (IC50 = 1–3 nmol/L) and in a stem cell factor–induced proliferation assay (IC50 = 13 nmol/L). Furthermore, phosphorylation of wild-type c-Kit in NCI-H526 tumor xenografts was reduced markedly following oral administration of cediranib (≥1.5 mg/kg/d) to tumor-bearing nude mice. The activity of cediranib against PDGFR-β and PDGFR-α was studied in tumor cell lines, vascular smooth muscle cells (VSMC), and a fibroblast line using PDGF-AA and PDGF-BB ligands. Both receptor phosphorylation (IC50 = 12–32 nmol/L) and PDGF-BB–stimulated cellular proliferation (IC50 = 32 nmol/L in human VSMCs; 64 nmol/L in osteosarcoma cells) were inhibited. In vivo, ligand-induced PDGFR-β phosphorylation in murine lung tissue was inhibited by 55% following treatment with cediranib at 6 mg/kg but not at 3 mg/kg or less. In contrast, in C6 rat glial tumor xenografts in mice, ligand-induced phosphorylation of both PDGFR-α and PDGFR-β was reduced by 46% to 61% with 0.75 mg/kg cediranib. Additional selectivity was showed versus Flt-3, CSF-1R, EGFR, FGFR1, and FGFR4. Collectively, these data indicate that cediranib is a potent pan-VEGFR kinase inhibitor with similar activity against c-Kit but is significantly less potent than PDGFR-α and PDGFR-β. Mol Cancer Ther; 10(5); 861–73. ©2011 AACR.
Interaction of Allergens, Major Histocompatibility Complex Molecules, and T Cell Receptors: A ‘Ménage à Trois’ That Opens New Avenues for Therapeutic Intervention in Type I Allergy
Authors: Jahn-Schmid Beatrice , Pickl Winfried F. , Bohle Barbara
Published: March 2011

T cells are major players in the initiation and perpetuation of the allergic immune response. In this review, we summarize the current knowledge on allergen recognition by T lymphocytes and address the components of the trimeric recognition complex: T cell receptors, major histocompatibility complex molecules, and allergen-derived peptides. Furthermore, possible implications of this scientific background for future therapeutic developments are discussed.
Niflumic Acid Reduces Histamine-Induced MUC5AC Expression in Human Conjunctival Epithelial Cells
Authors: Seo Kyoung Yul , Jeon Sohee , Choi Seong Hyun , Chung So-Hyang
Published: March 2011

Background/Aims: Histamine is an important inflammatory mediator in allergic conjunctivitis. The aim of the present study was to explore whether histamine induced MUC5AC production in human conjunctival epithelial cells (HCECs), and to describe the relationship between human calcium-activated chloride channel 1 (hCLCA1) activity and MUC5AC expression. Methods: HCECs were isolated from human conjunctiva and cultured at an air-liquid interface. MUC5AC and hCLCA1 mRNA expression was examined by real-time PCR after exposure of the cells to histamine. MUC5AC secretion was quantitated by ELISA. hCLCA1 protein was detected by Western blot analysis. Results: Histamine upregulated MUC5AC expression and MUC5AC secretion in a dose-dependent manner. Histamine also upregulated hCLCA1 mRNA expression in a dose-dependent manner. Preincubation of histamine receptor 1 antagonist reduced histamine-induced MUC5AC and hCLCA1 mRNA expression. Niflumic acid, a chloride channel inhibitor, reduced histamine-induced MUC5ACand hCLCA1 expression. Conclusion: Histamine-induced MUC5AC production could be decreased by niflumic acid, a calcium-activated chloride channel inhibitor.
Association of Vascular Risk Factors With Cervical Artery Dissection and Ischemic Stroke in Young Adults
Authors: Debette Stéphanie , Metso Tiina , Pezzini Alessandro , Abboud Shérine , Metso Antti , Leys Didier , Bersano Anna , Louillet Fabien , Caso Valeria , Lamy Chantal , Medeiros Elisabeth , Samson Yves , Grond-Ginsbach Caspar , Engelter Stefan T. , Thijs Vincent , Beretta Simone , Béjot Yannick , Sessa Maria , Lorenza Muiesan Maria , Amouyel Philippe , Castellano Maurizio , Arveiler Dominique , Tatlisumak Turgut , Dallongeville Jean
Published: March 2011

Background—

Little is known about the risk factors for cervical artery dissection (CEAD), a major cause of ischemic stroke (IS) in young adults. Hypertension, diabetes mellitus, smoking, hypercholesterolemia, and obesity are important risk factors for IS. However, their specific role in CEAD is poorly investigated. Our aim was to compare the prevalence of vascular risk factors in CEAD patients versus referents and patients who suffered an IS of a cause other than CEAD (non-CEAD IS) in the multicenter Cervical Artery Dissection and Ischemic Stroke Patients (CADISP) study.

Methods and Results—

The study sample comprised 690 CEAD patients (mean age, 44.2±9.9 years; 43.9% women), 556 patients with a non-CEAD IS (44.7±10.5 years; 39.9% women), and 1170 referents (45.9±8.1 years; 44.1% women). We compared the prevalence of hypertension, diabetes mellitus, hypercholesterolemia, smoking, and obesity (body mass index ≥30 kg/m
2
) or overweightness (body mass index ≥25 kg/m
2
and <30 kg/m
2
) between the 3 groups using a multinomial logistic regression adjusted for country of inclusion, age, and gender. Compared with referents, CEAD patients had a lower prevalence of hypercholesterolemia (odds ratio 0.55; 95% confidence interval, 0.42 to 0.71;
P
<0.0001), obesity (odds ratio 0.37; 95% confidence interval, 0.26 to 0.52;
P
<0.0001), and overweightness (odds ratio 0.70; 95% confidence interval, 0.57 to 0.88;
P
=0.002) but were more frequently hypertensive (odds ratio 1.67; 95% confidence interval, 1.32 to 2.1;
P
<0.0001). All vascular risk factors were less frequent in CEAD patients compared with young patients with a non-CEAD IS. The latter were more frequently hypertensive, diabetic, and current smokers compared with referents.

Conclusion—

These results, from the largest series to date, suggest that hypertension, although less prevalent than in patients with a non-CEAD IS, could be a risk factor of CEAD, whereas hypercholesterolemia, obesity, and overweightness are inversely associated with CEAD.
Mitral Regurgitation After Anteroapical Myocardial Infarction
Authors: Yosefy Chaim , Beeri Ronen , Guerrero J. Luis , Vaturi Mordehay , Scherrer-Crosbie Marielle , Handschumacher Mark D. , Levine Robert A.
Published: March 2011

Background—

Mitral regurgitation (MR) generally accompanies inferobasal myocardial infarction (MI), with leaflet tethering by displaced papillary muscles. Mitral regurgitation is also reported with anteroapical MI without global dilatation or inferior wall motion abnormalities. We hypothesized that anteroapical MI extending to the inferior apex displaces the papillary muscles, tethering the mitral leaflets to cause MR.

Methods and Results—

In the retrospective part of the study, consecutive anteroapical MI patients were studied. Moderate-severe MR occurred in 9% of 234 patients with only anteroapical MI versus 17% of 242 with inferoapical extension (
P
<0.001). Ejection fraction was only mildly different (41±4% versus 46±5%;
P
<0.01). In the human mechanistic portion of the study, 60 anteroapical MI patients (20 with only 2 apical segments involved and 40 with involvement of all 4 apical segments; 20 with MR and 20 without MR) were compared with 20 normal controls. Those with MR (≥moderate) had higher systolic papillary muscle–to-annulus tethering length (
P
<0.01). Mitral regurgitation grade correlated most strongly with tethering length (
r
=0.70) and its diminished systolic shortening (
r
=−0.65). In the animal study, 9 sheep with left anterior descending coronary artery ligation were analyzed. Four sheep that developed MR had inferoapical MI extension with tethering length increasing over 1.5 months (2.1±0.4 to 2.9±0.4 cm,
P
<0.001) versus no significant increase in 5 sheep without MR (2.0±0.4 to 2.1±0.3 cm,
P
not statistically significant). In MR sheep, the normal decrease in tethering length from diastole to systole was eliminated (
P
<0.01).

Conclusions—

Anteroapical MI with inferoapical extension can mechanically displace papillary muscles, causing MR despite the absence of basal and midinferior wall motion abnormalities. This suggests the possibility of repositioning treatments for this condition.
A Spatiotemporal Analysis of Historical Droughts in Korea
Authors: Kim Do-Woo , Byun Hi-Ryong , Choi Ki-Seon , Oh Su-Bin
Published: March 2011

The climatological characteristics of drought in South Korea were investigated using daily precipitation data for 1777–2008. The effective drought index was used to quantify the drought intensity. As a result, five characteristics were discovered. First, South Korea can be divided into four drought subregions (the central, southern, and east coastal regions and Jeju Island) using hierarchical cluster analysis. Second, a map for long-term drought conditions in the four subregions is created that allows identification of the spatiotemporal distribution of droughts for the 231 yr at a glance. Third, droughts in South Korea have time scales that depend on the onset season. Spring (March–May) droughts tend to be short (≤200 days) because the summer (June–September) rainy season follows. Summer droughts tend to be long (>200 days) because the dry season (October–February) follows. In the dry season, droughts tend to be sustained or become severe rather than being initiated or relieved. Fourth, 5-, 14-, 34-, and 115-yr drought cycles were identified by spectral analysis. The 5-yr cycle was dominant in all of the regions, the 14-yr cycle was observed over the southern and east coastal regions, and the 34-yr cycle was observed over the central region. Fifth, the most extreme drought occurred in 1897–1903 (return period: 233 yr) and was associated with the 115-yr drought cycle. After this drought, severe droughts (return period of >10 yr) occurred in 1927–30, 1938–40, 1942–45, 1951–52, 1967–69, and 1994–96; they were caused by the consecutive shortage of summer rainfall for two or more years.
Impact of Aligning Climatological Day on Gridding Daily Maximum–Minimum Temperature and Precipitation over Canada
Authors: Hopkinson Ron F. , McKenney Daniel W. , Milewska Ewa J. , Hutchinson Michael F. , Papadopol Pia , Vincent Lucie A.
Published: March 2011

On 1 July 1961, the climatological day was redefined to end at 0600 UTC at all principal climate stations in Canada. Prior to that, the climatological day at principal stations ended at 1200 UTC for maximum temperature and precipitation and 0000 UTC for minimum temperature and was similar to the climatological day at ordinary stations. Hutchinson et al. reported occasional larger-than-expected residuals at 50 withheld stations when the Australian National University Spline (ANUSPLIN) interpolation scheme was applied to daily data for 1961–2003, and it was suggested that these larger residuals were in part due to the existence of different climatological days. In this study, daily minimum and maximum temperatures at principal stations were estimated using hourly temperatures for the same climatological day as local ordinary climate stations for the period 1953–2007. Daily precipitation was estimated at principal stations using synoptic precipitation data for the climatological day ending at 1200 UTC, which, for much of the country, was close to the time of the morning observation at ordinary climate stations. At withheld principal stations, the climatological-day adjustments led to the virtual elimination of large residuals in maximum and minimum temperature and a marked reduction in precipitation residuals. Across all 50 withheld stations the climatological day adjustments led to significant reductions, by around 12% for daily maximum temperature, 15% for daily minimum temperature, and 22% for precipitation, in the residuals reported by Hutchinson et al.