Bias stress instability of double-gate a-IGZO TFTs on polyimide substrate

Science.gov (United States)

Cho, Won-Ju; Ahn, Min-Ju

2017-09-01

In this study, flexible double-gate thin-film transistor (TFT)-based amorphous indium-galliumzinc- oxide (a-IGZO) was fabricated on a polyimide substrate. Double-gate operation with connected front and back gates was compared with a single-gate operation. As a result, the double-gate a- IGZO TFT exhibited enhanced electrical characteristics as well as improved long-term reliability. Under positive- and negative-bias temperature stress, the threshold voltage shift of the double-gate operation was much smaller than that of the single-gate operation.

Domain-domain interactions determine the gating, permeation, pharmacology, and subunit modulation of the IKs ion channel.

Science.gov (United States)

Zaydman, Mark A; Kasimova, Marina A; McFarland, Kelli; Beller, Zachary; Hou, Panpan; Kinser, Holly E; Liang, Hongwu; Zhang, Guohui; Shi, Jingyi; Tarek, Mounir; Cui, Jianmin

2014-12-23

Voltage-gated ion channels generate electrical currents that control muscle contraction, encode neuronal information, and trigger hormonal release. Tissue-specific expression of accessory (β) subunits causes these channels to generate currents with distinct properties. In the heart, KCNQ1 voltage-gated potassium channels coassemble with KCNE1 β-subunits to generate the IKs current (Barhanin et al., 1996; Sanguinetti et al., 1996), an important current for maintenance of stable heart rhythms. KCNE1 significantly modulates the gating, permeation, and pharmacology of KCNQ1 (Wrobel et al., 2012; Sun et al., 2012; Abbott, 2014). These changes are essential for the physiological role of IKs (Silva and Rudy, 2005); however, after 18 years of study, no coherent mechanism explaining how KCNE1 affects KCNQ1 has emerged. Here we provide evidence of such a mechanism, whereby, KCNE1 alters the state-dependent interactions that functionally couple the voltage-sensing domains (VSDs) to the pore.

Domain–domain interactions determine the gating, permeation, pharmacology, and subunit modulation of the IKs ion channel

Science.gov (United States)

Zaydman, Mark A; Kasimova, Marina A; McFarland, Kelli; Beller, Zachary; Hou, Panpan; Kinser, Holly E; Liang, Hongwu; Zhang, Guohui; Shi, Jingyi; Tarek, Mounir; Cui, Jianmin

2014-01-01

Voltage-gated ion channels generate electrical currents that control muscle contraction, encode neuronal information, and trigger hormonal release. Tissue-specific expression of accessory (β) subunits causes these channels to generate currents with distinct properties. In the heart, KCNQ1 voltage-gated potassium channels coassemble with KCNE1 β-subunits to generate the IKs current (Barhanin et al., 1996; Sanguinetti et al., 1996), an important current for maintenance of stable heart rhythms. KCNE1 significantly modulates the gating, permeation, and pharmacology of KCNQ1 (Wrobel et al., 2012; Sun et al., 2012; Abbott, 2014). These changes are essential for the physiological role of IKs (Silva and Rudy, 2005); however, after 18 years of study, no coherent mechanism explaining how KCNE1 affects KCNQ1 has emerged. Here we provide evidence of such a mechanism, whereby, KCNE1 alters the state-dependent interactions that functionally couple the voltage-sensing domains (VSDs) to the pore. DOI: http://dx.doi.org/10.7554/eLife.03606.001 PMID:25535795

Complications during pharmacological stress echocardiography: a video-case series

Directory of Open Access Journals (Sweden)

Bigi Riccardo

2005-09-01

Full Text Available Abstract Background Stress echocardiography is a cost-effective tool for the modern noninvasive diagnosis of coronary artery disease. Several physical and pharmacological stresses are used in combination with echocardiographic imaging, usually exercise, dobutamine and dipyridamole. The safety of a stress is (or should be a major determinant in the choice of testing. Although large scale single center experiences and multicenter trial information are available for both dobutamine and dipyridamole stress echo testing, complications or side effects still can occur even in the most experienced laboratories with the most skilled operators. Case presentation We decided to present a case collection of severe complications during pharmacological stress echo testing, including a ventricular tachycardia, cardiogenic shock, transient ischemic attack, torsade de pointe, fatal ventricular fibrillation, and free wall rupture. Conclusion We believe that, in this field, every past complication described is a future complication avoided; what happens in your lab is more true of what you read in journals; and Good Clinical Practice is not "not having complications", but to describe the complications you had.

Comparison of exercise and pharmacologic stress in myocardium perfusion imaging for CHD

International Nuclear Information System (INIS)

Li Zebo; Zheng Kangni; Cheng Xiaorui; Liu Hui; Cheng Yihai

1995-01-01

In order to provide a proper stress test, exercise, dipyridamole and ATP stress were compared. Three modalities were compared with respect to the detecting rate, methodology, hemodynamic and side effects. There are no significant differences in their ability of detecting coronary heart disease (CHD) (P>0.05). Exercise stress causes an increase in heart rate, blood pressure and myocardium oxygen consumption. Pharmacologic stress cause a slight increase in heart rate, but a decrease in blood pressure (P<0.01). Exercise stress is a basic method with good image quality, but it needs a special equipment. Pharmacologic stress is an easier, cheaper and safer method, particularly useful for patients unable to perform exercise test

Degradation of Ultra-Thin Gate Oxide NMOSFETs under CVDT and SHE Stresses

International Nuclear Information System (INIS)

Shi-Gang, Hu; Yan-Rong, Cao; Yue, Hao; Xiao-Hua, Ma; Chi, Chen; Xiao-Feng, Wu; Qing-Jun, Zhou

2008-01-01

Degradation of device under substrate hot-electron (SHE) and constant voltage direct-tunnelling (CVDT) stresses are studied using NMOSFET with 1.4-nm gate oxides. The degradation of device parameters and the degradation of the stress induced leakage current (SILC) under these two stresses are reported. The emphasis of this paper is on SILC and breakdown of ultra-thin-gate-oxide under these two stresses. SILC increases with stress time and several soft breakdown events occur during direct-tunnelling (DT) stress. During SHE stress, SILC firstly decreases with stress time and suddenly jumps to a high level, and no soft breakdown event is observed. For DT injection, the positive hole trapped in the oxide and hole direct-tunnelling play important roles in the breakdown. For SHE injection, it is because injected hot electrons accelerate the formation of defects and these defects formed by hot electrons induce breakdown. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Defect images in stress thallium-201 myocardial scintigraphy in patients with complete left bundle branch block. Comparison of exercise stress and pharmacological stress

International Nuclear Information System (INIS)

Sasaki, Hideki; Shimizu, Mitsuyuki; Ogawa, Kazuhiko; Okazaki, Fumiko; Mizokami, Tsuneo; Kusaka, Masafumi; Uehara, Yoshiki; Taniguchi, Ikuo; Mochizuki, Seibu

2007-01-01

Stress thallium-201 ( 201 Tl) myocardial scintigraphy can demonstrate perfusion abnormalities, especially in the septum in patients with complete left bundle branch block (CLBBB) even with angiographically normal coronary arteries. Differences in the images between exercise and pharmacological stress 201 Tl myocardial scintigraphy were evaluated in patients with CLBBB and normal coronary arteries. Forty-five patients with CLBBB underwent exercise stress using treadmill or pharmacological (adenosine triphosphate) stress 201 Tl myocardial scintigraphy from October 1997 to February 2003. Patients with myocardial diseases were excluded, such as cardiomyopathy and coronary artery diseases detected by echocardiography and/or cardiac catheterization. The myocardial segment was classified according to the American Heart Association style for coronary artery disease. Peak blood pressure levels and heart rates were significantly higher in the exercise stress group than in the pharmacological stress group (p 201 Tl myocardial scintigraphy according to the stress method. Moreover, defects also occurred in areas other than the septum. Blood pressure and heart rate were involved in the mechanisms of defects in left bundle branch block. (author)

Investigating degradation behavior of hole-trapping effect under static and dynamic gate-bias stress in a dual gate a-InGaZnO thin film transistor with etch stop layer

Energy Technology Data Exchange (ETDEWEB)

Liao, Po-Yung [Department of Physics, National Sun Yat-sen University, 70 Lien-hai Road, Kaohsiung 80424, Taiwan (China); Chang, Ting-Chang, E-mail: tcchang3708@gmail.com [Department of Physics, National Sun Yat-sen University, 70 Lien-hai Road, Kaohsiung 80424, Taiwan (China); Advanced Optoelectronics Technology Center, National Cheng Kung University, Taiwan (China); Hsieh, Tien-Yu [Department of Physics, National Sun Yat-sen University, 70 Lien-hai Road, Kaohsiung 80424, Taiwan (China); Tsai, Ming-Yen; Chen, Bo-Wei; Chu, Ann-Kuo [Department of Photonics, National Sun Yat-Sen University, 70 Lien-hai Road, Kaohsiung 80424, Taiwan (China); Chou, Cheng-Hsu; Chang, Jung-Fang [Product Technology Center, Chimei Innolux Corp., Tainan 741, Taiwan (China)

2016-03-31

The degree of degradation between the amorphous-indium–gallium–zinc oxide (a-IGZO) thin film transistor (TFT) using the top-gate only or bottom-gate only is compared. Under negative gate bias illumination stress (NBIS), the threshold voltage (V{sub T}) after bottom-gate NBIS monotonically shifts in the negative direction, whereas top-gate NBIS operation exhibits on-state current increases without V{sub T} shift. Such anomalous degradation behavior of NBIS under top-gate operation is due to hole-trapping in the etch stop layer above the central portion of the channel. These phenomena can be ascribed to the screening of the electric field by redundant source/drain electrodes. In addition, the device degradation of dual gate a-IGZO TFT stressed with different top gate pulse waveforms is investigated. It is observed that the degradation is dependent on the frequency of the top gate pulses. The V{sub T} shift increases with decreasing frequency, indicating the hole mobility of IGZO is low. - Highlights: • Static and dynamic gate bias stresses are imposed on dual gate InGaZnO TFTs. • Top-gate NBIS operation exhibits on-state current increases without VT shift. • The degradation behavior of top-gate NBIS is due to hole-trapping in the ESL. • The degradation is dependent on the frequency of the top gate pulses. • The V{sub T} shift increases with decreasing frequency of the top gate pulses.

Investigating degradation behavior of hole-trapping effect under static and dynamic gate-bias stress in a dual gate a-InGaZnO thin film transistor with etch stop layer

International Nuclear Information System (INIS)

Liao, Po-Yung; Chang, Ting-Chang; Hsieh, Tien-Yu; Tsai, Ming-Yen; Chen, Bo-Wei; Chu, Ann-Kuo; Chou, Cheng-Hsu; Chang, Jung-Fang

2016-01-01

The degree of degradation between the amorphous-indium–gallium–zinc oxide (a-IGZO) thin film transistor (TFT) using the top-gate only or bottom-gate only is compared. Under negative gate bias illumination stress (NBIS), the threshold voltage (V T ) after bottom-gate NBIS monotonically shifts in the negative direction, whereas top-gate NBIS operation exhibits on-state current increases without V T shift. Such anomalous degradation behavior of NBIS under top-gate operation is due to hole-trapping in the etch stop layer above the central portion of the channel. These phenomena can be ascribed to the screening of the electric field by redundant source/drain electrodes. In addition, the device degradation of dual gate a-IGZO TFT stressed with different top gate pulse waveforms is investigated. It is observed that the degradation is dependent on the frequency of the top gate pulses. The V T shift increases with decreasing frequency, indicating the hole mobility of IGZO is low. - Highlights: • Static and dynamic gate bias stresses are imposed on dual gate InGaZnO TFTs. • Top-gate NBIS operation exhibits on-state current increases without VT shift. • The degradation behavior of top-gate NBIS is due to hole-trapping in the ESL. • The degradation is dependent on the frequency of the top gate pulses. • The V T shift increases with decreasing frequency of the top gate pulses.

Evaluation of Anisotropic Biaxial Stress Induced Around Trench Gate of Si Power Transistor Using Water-Immersion Raman Spectroscopy

Science.gov (United States)

Suzuki, Takahiro; Yokogawa, Ryo; Oasa, Kohei; Nishiwaki, Tatsuya; Hamamoto, Takeshi; Ogura, Atsushi

2018-05-01

The trench gate structure is one of the promising techniques to reduce on-state resistance (R on) for silicon power devices, such as insulated gate bipolar transistors and power metal-oxide-semiconductor field-effect transistors. In addition, it has been reported that stress is induced around the trench gate area, modifying the carrier mobilities. We evaluated the one-dimensional distribution and anisotropic biaxial stress by quasi-line excitation and water-immersion Raman spectroscopy, respectively. The results clearly confirmed anisotropic biaxial stress in state-of-the-art silicon power devices. It is theoretically possible to estimate carrier mobility using piezoresistance coefficients and anisotropic biaxial stress. The electron mobility was increased while the hole mobility was decreased or remained almost unchanged in the silicon (Si) power device. The stress significantly modifies the R on of silicon power transistors. Therefore, their performance can be improved using the stress around the trench gate.

Thermal Stress Cracking of Slide-Gate Plates in Steel Continuous Casting

Science.gov (United States)

Lee, Hyoung-Jun; Thomas, Brian G.; Kim, Seon-Hyo

2016-04-01

The slide-gate plates in a cassette assembly control the steel flow through the tundish nozzle, and may experience through-thickness cracks, caused by thermal expansion and/or mechanical constraint, leading to air aspiration and safety concerns. Different mechanisms for common and rare crack formation are investigated with the aid of a three-dimensional finite-element model of thermal mechanical behavior of the slide-gate plate assembly during bolt pretensioning, preheating, tundish filling, casting, and cooling stages. The model was validated with previous plant temperature measurements of a ladle plate during preheating and casting, and then applied to a typical tundish-nozzle slide-gate assembly. The formation mechanisms of different types of cracks in the slide-gate plates are investigated using the model and evaluated with actual slide-gate plates at POSCO. Common through-thickness radial cracks, found in every plate, are caused during casting by high tensile stress on the outside surfaces of the plates, due to internal thermal expansion. In the upper plate, these cracks may also arise during preheating or tundish filling. Excessive bolt tightening, combined with thermal expansion during casting may cause rare radial cracks in the upper and lower plates. Rare radial and transverse cracks in middle plate appear to be caused during tundish filling by impingement of molten steel on the middle of the middle plate that generates tensile stress in the surrounding refractory. The mechanical properties of the refractory, the bolt tightening conditions, and the cassette/plate design are all important to service life.

The TDDB Characteristics of Ultra-Thin Gate Oxide MOS Capacitors under Constant Voltage Stress and Substrate Hot-Carrier Injection

Directory of Open Access Journals (Sweden)

Jingyu Shen

2018-01-01

Full Text Available The breakdown characteristics of ultra-thin gate oxide MOS capacitors fabricated in 65 nm CMOS technology under constant voltage stress and substrate hot-carrier injection are investigated. Compared to normal thick gate oxide, the degradation mechanism of time-dependent dielectric breakdown (TDDB of ultra-thin gate oxide is found to be different. It is found that the gate current (Ig of ultra-thin gate oxide MOS capacitor is more likely to be induced not only by Fowler-Nordheim (F-N tunneling electrons, but also by electrons surmounting barrier and penetrating electrons in the condition of constant voltage stress. Moreover it is shown that the time to breakdown (tbd under substrate hot-carrier injection is far less than that under constant voltage stress when the failure criterion is defined as a hard breakdown according to the experimental results. The TDDB mechanism of ultra-thin gate oxide will be detailed. The differences in TDDB characteristics of MOS capacitors induced by constant voltage stress and substrate hot-carrier injection will be also discussed.

Targeting ligand-gated ion channels in neurology and psychiatry: is pharmacological promiscuity an obstacle or an opportunity?

Science.gov (United States)

Bianchi, Matt T; Botzolakis, Emmanuel J

2010-03-02

The traditional emphasis on developing high specificity pharmaceuticals ("magic bullets") for the treatment of Neurological and Psychiatric disorders is being challenged by emerging pathophysiology concepts that view disease states as abnormal interactions within complex networks of molecular and cellular components. So-called network pharmacology focuses on modifying the behavior of entire systems rather than individual components, a therapeutic strategy that would ideally employ single pharmacological agents capable of interacting with multiple targets ("magic shotguns"). For this approach to be successful, however, a framework for understanding pharmacological "promiscuity"--the ability of individual agents to modulate multiple molecular targets--is needed. Pharmacological promiscuity is more often the rule than the exception for drugs that target the central nervous system (CNS). We hypothesize that promiscuity is an important contributor to clinical efficacy. Modulation patterns of existing therapeutic agents may provide critical templates for future drug discovery in Neurology and Psychiatry. To demonstrate the extent of pharmacological promiscuity and develop a framework for guiding drug screening, we reviewed the ability of 170 therapeutic agents and endogenous molecules to directly modulate neurotransmitter receptors, a class of historically attractive therapeutic targets in Neurology and Psychiatry. The results are summarized in the form of 1) receptor-centric maps that illustrate the degree of promiscuity for GABA-, glycine-, serotonin-, and acetylcholine-gated ion channels, and 2) drug-centric maps that illustrated how characterization of promiscuity can guide drug development. Developing promiscuity maps of approved neuro-pharmaceuticals will provide therapeutic class-based templates against which candidate compounds can be screened. Importantly, compounds previously rejected in traditional screens due to poor specificity could be reconsidered in this

Investigating degradation behavior of InGaZnO thin-film transistors induced by charge-trapping effect under DC and AC gate bias stress

International Nuclear Information System (INIS)

Hsieh, Tien-Yu; Chang, Ting-Chang; Chen, Te-Chih; Tsai, Ming-Yen; Chen, Yu-Te

2013-01-01

This paper investigates the degradation mechanism of amorphous InGaZnO thin-film transistors under DC and AC gate bias stress. Comparing the degradation behavior at equal accumulated effective stress time, more pronounced threshold voltage shift under AC positive gate bias stress in comparison with DC stress indicates extra electron-trapping phenomenon that occurs in the duration of rising/falling time in pulse. Contrarily, illuminated AC negative gate bias stress exhibits much less threshold voltage shift than DC stress, suggesting that the photo-generated hole does not have sufficient time to drift to the interface of IGZO/gate insulator and causes hole-trapping under AC operation. Since the evolution of threshold voltage fits the stretched-exponential equation well, the different degradation tendencies under DC/AC stress can be attributed to the different electron- and hole-trapping efficiencies, and this is further verified by varying pulse waveform. - Highlights: ► Static and dynamic gate bias stresses are imposed on InGaZnO TFTs. ► Dynamic positive gate bias induces more pronounced threshold voltage shift. ► Static negative-bias illumination stress induces more severe threshold voltage shift. ► Evolution of threshold voltage fits the stretched-exponential equation well

Magnetic resonance pharmacological stress for detecting coronary disease. Comparison with echocardiography

International Nuclear Information System (INIS)

Baer, F.M.; Crnac, J.; Jochims, M.; Schneider, C.; Erdmann, E.; Schmidt, M.; Theissen, P.; Schicha, H.

2000-01-01

Stress testing is the cornerstone in the diagnosis of patients with suspected coronary artery disease (CAD). Although exercise ECG remains the primary approach for the detection of ischemia in patients with chest pain syndromes, its sensitivity and specificity is limited and exercise ECG does not provide detailed information about the localisation and extent of CAD. Stress echocardiography has been used for the detection of ischemia for more than a decade and has become an increasingly popular noninvasive method for the detection of CAD. In experienced hands wall motion analysis based on stress echocardiography has proved to be as sensitive and specific for the detection of myocardial ischemia as scintigraphic techniques. Recent technical improvements, namely the availability of ultrafast imaging sequences with a significant reduction of imaging time have initiated several studies which examined the combination of pharmacological stress and magnetic resonance imaging (MRI) for the detection of suspected CAD. The most well developed stress-MRI technique is wall motion imaging during dobutamine stress. This technique is analogous to stress echocardiography, but MRI has the inherent advantages of better resolution, higher reproducibility and true long and short axis imaging with contiguous parallel slices. However, the clinical impact of MRI for the diagnosis of CAD is still low. Further technical developments including real time imaging and a reliable automated quantitative analysis of left ventricular function are required before stress-MRI becomes a serious challenge to stressechocardiography in the clinical arena. Currently, only a few MRI facilities and physicians are dedicated to pharmacological stress testing with MRI and the future clinical impact of this promising technique will depend on its potential to provide information beyond myocardial function including perfusion, metabolism and coronary anatomy in form of a ''one-stop''-shop for the cardiac patient

Minority Carrier Tunneling and Stress-Induced Leakage Current for p+ gate MOS Capacitors with Poly-Si and PolySi0.7Ge0.3 Gate Material

NARCIS (Netherlands)

Houtsma, V.E.; Holleman, J.; Salm, Cora; de Haan, I.R.; Schmitz, Jurriaan; Widdershoven, F.P.; Widdershoven, F.P.; Woerlee, P.H.

1999-01-01

In this paper the I-V conduction mechanism for gate injection (-V g), Stress-Induced Leakage Current (SILC) characteristics and time-to-breakdown (tbd) of PMOS capacitors with p+-poly-Si and poly-SiGe gate material on 5.6, 4.8 and 3.1 nm oxide thickness are studied. A model based on Minority Carrier

Development of a time-dependent energy model to calculate the mining-induced stress over gates and pillars

Directory of Open Access Journals (Sweden)

Mohammad Rezaei

2015-06-01

Full Text Available Generally, longwall mining-induced stress results from the stress relaxation due to destressed zone that occurs above the mined panel. Knowledge of induced stress is very important for accurate design of adjacent gateroads and intervening pillars which helps to raise the safety and productivity of longwall mining operations. This study presents a novel time-dependent analytical model for determination of the longwall mining-induced stress and investigates the coefficient of stress concentration over adjacent gates and pillars. The model is developed based on the strain energy balance in longwall mining incorporated to a rheological constitutive model of caved materials with time-varying parameters. The study site is the Tabas coal mine of Iran. In the proposed model, height of destressed zone above the mined panel, total longwall mining-induced stress, abutment angle, induced vertical stress, and coefficient of stress concentration over neighboring gates and intervening pillars are calculated. To evaluate the effect of proposed model parameters on the coefficient of stress concentration due to longwall mining, sensitivity analysis is performed based on the field data and experimental constants. Also, the results of the proposed model are compared with those of existing models. The comparative results confirm a good agreement between the proposed model and the in situ measurements. According to the obtained results, it is concluded that the proposed model can be successfully used to calculate the longwall mining-induced stress. Therefore, the optimum design of gate supports and pillar dimensions would be attainable which helps to increase the mining efficiency.

Diagnostic value of rest and stress gated 82Rb PET myocardial perfusion imaging using quantitative software

International Nuclear Information System (INIS)

Shi Hongcheng; Gu Yusen; Liu Wenguan; Zhu Weimin; Halkar, R.K.; Santana, C.A.; Feng Yusheng

2008-01-01

Objective: Gated myocardial perfusion imaging (MPI) is regularly performed using SPECT. More recently, gated 82 Rb MPI has been used to assess left ventricular myocardial perfusion and function with new generation PET scanners. The objective of this study was to evaluate the value of rest and stress gated 82 Rb PET myocardial perfusion imaging and to determine whether the quantitative technique in- creased the confidence level of the interpreters. Methods: Thirty-two patients underwent rest and adenosine stress gated 82 Pb PET MPI. Emory Cardiac Toolbox quantitative software was used for processing and inter-predation. Left ventricular ejection fraction (LVEF), end-diastolic, end-systolic and transient ischemia dilation ratio were automatically generated. Three interpreters (nuclear medicine doctors) independently reviewed the studies. Visual scoring (1-5 scales: excellent, good, unsure, poor, uninterpretable) was used to assess the overall quality of the gated images and the added confidence level of interpretation. Visual assessment of the LVEF was compared to the automatically generated LVEF. Comparison between the visual assessment and software generated was graded on a 1- 5 scales (helpful, probably helpful, unsure, probably not helpful, definitely not helpful). The analysed items were divided into two groups (favorable group and negative group). The percentage and 95% confidence intervals of each group were calculated. Results: A total of 192 gated studies were evaluated (64 gated x 3 interpreters ). The overall quality of the gated images was good [excellent 40.1% (77/192), good 43.2% (83/192), unsure 3.1% (6/192), poor 13.6% (26/192), uninterpretable 0]. The 95% confidence intervals of good and excellent quality range from 78.1% to 88.6%. The interpreter's agreed with the automated LVEF on 85.4% of the gated images [agree 76.6% (147/192), probably agree 8.8% (17/192), unsure 3.1% (6/192), probably disagree 8.8% (17/192), disagree 2.6% (5/192)]. And its 95

The role of pharmacological stress Tc-99m sestamibi myocardial perfusion imaging in an Australian population

International Nuclear Information System (INIS)

Howarth, D.M.; Booker, J.A.; Tan, T.S.K.; Bellamy, G.R.; Hardy, D.B.; Howarth, G.C.

2003-01-01

This observational study was performed in order to assess the exercise-related incremental diagnostic accuracy of Tc-99m sestamibi myocardial perfusion imaging (MPI) in a hospital-based Australian population, and to assess the relative roles of exercise and pharmacological stress in myocardial perfusion imaging (MPI). Two hundred and eight adult patients who had both Tc-99m sestamibi myocardial perfusion imaging and coronary angiography within a median time of 16 weeks were studied. The diagnostic end-point was coronary artery lesions of ≥50% and >70% stenosis detected on angiography. Using receiver operating characteristic curve analysis, the overall diagnostic accuracy was calculated, as well as the comparative accuracies in patients who undertook various levels of exercise stress testing (n=130) and those who received pharmacological (dipyridamole) stress testing (n=78). The overall respective diagnostic accuracy of Tc-99m sestamibi MPI for the diagnosis of coronary artery disease (>70% stenosis) was 81% and 76% when using the diagnostic criterion of ≥50% stenosis. On direct comparison of perfusion defects with angiographic stenoses, the respective sensitivity and specificity for the detection of >70% stenosis in each coronary artery territory was 73% and 79%. Pharmacological MPI showed a significantly greater sensitivity for the detection of localised stenoses compared to the overall group who had exercise MPI performed. Consequently, exercise stress MPI showed significantly more false negative lesions compared to dipyridamole stress imaging (p<0.003). However, a large proportion of patients were unable to perform to adequate exercise levels in this patient sample. We conclude that Tc-99m sestamibi myocardial perfusion imaging is an accurate non-invasive test for the diagnosis of coronary artery disease. Where any doubt exists as to the patient's ability to achieve exercise levels at or above 85% of the predicted value for age and gender, pharmacological

A clinical study of gated simultaneous rest 201Tl/stress 99Tcm-sestamibi dual isotope myocardial perfusion imaging

International Nuclear Information System (INIS)

Tang Anwu; Qiao Shuixian; Luo Yaowu; Liang Xiaolin

2002-01-01

Objective: To investigate a modified gated radionuclide myocardial tomography in methodology for raising the sensitivity and efficiency of detecting myocardial ischemia. Methods: One hundred and three patients were involved and divided into two groups: coronary artery disease (CAD) patient 37, non-CAD patient 66. 201 Tl 111 MBq was injected intravenously 5 min before stress, the patient exercised with ergometer following the modified Bruce protocol, and was injected 99 Tc m -sestamibi at the peak of stress. 45 min later, the simultaneous dual energy peak gated acquisition was then performed. Stress ( 99 Tc m -sestamibi) and rest ( 201 Tl) images were reconstructed. Results: Positive findings were seen in 35/37 (94.6%) in CAD group and 7/66 (10.6%) in non-CAD, respectively; LVEF, EDV and ESV of two groups were (52.33+-16.26)%, (70.45+-28.12) mL, (33.35 +- 18.86) mL and (61.76 +- 9.38)%, (60.45 +- 18.18) mL, (23.30 +- 11.09) mL, respectively. Conclusion: The simultaneous stress ( 99 Tc m -sestamibi) and rest ( 201 Tl) gated myocardial imaging is an efficient and practical protocol for the study of myocardial perfusion and the diagnosis of ischemia

A study on the degradation mechanism of InGaZnO thin-film transistors under simultaneous gate and drain bias stresses based on the electronic trap characterization

International Nuclear Information System (INIS)

Jeong, Chan-Yong; Lee, Daeun; Song, Sang-Hun; Kwon, Hyuck-In; Kim, Jong In; Lee, Jong-Ho

2014-01-01

We discuss the device degradation mechanism of amorphous indium–gallium–zinc oxide (a-IGZO) thin-film transistors (TFTs) under simultaneous gate and drain bias stresses based on the electronic trap characterization results. The transfer curve exhibits an apparent negative shift as the stress time increases, and a formation of hump is observed in the transfer curve after stresses. A notable increase of the frequency dispersion is observed after stresses in both gate-to-drain capacitance–voltage (C GD –V G ) and gate-to-source capacitance–voltage (C GS –V G ) curves, which implies that the subgap states are generated by simultaneous gate and drain bias stresses, and the damaged location is not limited to the drain side of TFTs. The larger frequency dispersion is observed in C GD –V G  curves after stresses in a wider channel device, which implies that the heat is an important factor in the generation of the subgap states under simultaneous gate and drain bias stresses in a-IGZO TFTs. Based on the electronic trap characterization results, we conclude that the impact ionization near the drain side of the device is not a dominant mechanism causing the generation of subgap states and device degradation in a-IGZO TFTs under simultaneous gate and drain bias stresses. The generation of oxygen vacancy-related donor-like traps near the conduction band edge is considered as a possible mechanism causing the device degradation under simultaneous gate and drain bias stresses in a-IGZO TFTs. (paper)

Performance of organic field effect transistors with high-k gate oxide after application of consecutive bias stress

Energy Technology Data Exchange (ETDEWEB)

Lee, Sunwoo; Choi, Changhwan; Lee, Kilbock [Department of Materials Science and Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of); Cho, Joong Hwee [Department of Embedded Systems Engineering,University of Incheon, Incheon 406-722 (Korea, Republic of); Ko, Ki-Young [Korea Institute of Patent Information, Seoul, 146-8 (Korea, Republic of); Ahn, Jinho, E-mail: jhahn@hanyang.ac.kr [Department of Materials Science and Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of)

2012-10-30

We report the effect of consecutive electrical stress on the performance of organic field effect transistors (OFETs). Sputtered aluminum oxide (Al{sub 2}O{sub 3}) and hafnium oxide (HfO{sub 2}) were used as gate oxide layers. After the electrical stress, the threshold voltage, which strongly depends on bulk defects, was remarkably shifted to the negative direction, while the other performance characteristics of OFETs such as on-current, transconductance and mobility, which are sensitive to interface defects, were slightly decreased. This result implies that the defects in the bulk layer are significantly affected compared to the defects in the interface layer. Thus, it is important to control the defects in the pentacene bulk layer in order to maintain the good reliabilities of pentacene devices. Those defects in HfO{sub 2} gate oxide devices were larger compared to those in Al{sub 2}O{sub 3} gate oxide devices.

From non-pharmacological treatments for post-traumatic stress disorder to novel therapeutic targets

NARCIS (Netherlands)

Hendriksen, Erik; Olivier, Berend; Oosting, Ronald S

2014-01-01

The development of new pharmacological therapies starts with target discovery. Finding new therapeutic targets for anxiety disorders is a difficult process. Most of the currently described drugs for post-traumatic stress disorder (PTSD) are based on the inhibition of serotonin reuptake. The

Investigation of abrupt degradation of drain current caused by under-gate crack in AlGaN/GaN high electron mobility transistors during high temperature operation stress

Energy Technology Data Exchange (ETDEWEB)

Zeng, Chang; Liao, XueYang; Li, RuGuan; Wang, YuanSheng; Chen, Yiqiang, E-mail: yiqiang-chen@hotmail.com; Su, Wei; Liu, Yuan; Wang, Li Wei; Lai, Ping; Huang, Yun; En, YunFei [Science and Technology on Reliability Physics and Application of Electronic Component Laboratory, The 5th Electronics Research Institute of the Ministry of Industry and Information Technology, 510610 Guangzhou (China)

2015-09-28

In this paper, we investigate the degradation mode and mechanism of AlGaN/GaN based high electron mobility transistors (HEMTs) during high temperature operation (HTO) stress. It demonstrates that there was abrupt degradation mode of drain current during HTO stress. The abrupt degradation is ascribed to the formation of crack under the gate which was the result of the brittle fracture of epilayer based on failure analysis. The origin of the mechanical damage under the gate is further investigated and discussed based on top-down scanning electron microscope, cross section transmission electron microscope and energy dispersive x-ray spectroscopy analysis, and stress simulation. Based on the coupled analysis of the failure physical feature and stress simulation considering the coefficient of thermal expansion (CTE) mismatch in different materials in gate metals/semiconductor system, the mechanical damage under the gate is related to mechanical stress induced by CTE mismatch in Au/Ti/Mo/GaN system and stress concentration caused by the localized structural damage at the drain side of the gate edge. These results indicate that mechanical stress induced by CTE mismatch of materials inside the device plays great important role on the reliability of AlGaN/GaN HEMTs during HTO stress.

Comparing Pharmacological Modulation of Sensory Gating in Healthy Humans and Rats

DEFF Research Database (Denmark)

Witten, Louise; Bastlund, Jesper Frank; Glenthøj, Birte Y

2016-01-01

following a dose of either reboxetine (8 mg), haloperidol (2 mg), their combination or placebo at four separate visits. Similarly in the animal experiment sensory gating was assessed in rats, (n=22) following a dose of reboxetine (2 mg/kg), haloperidol (0.08 mg/kg), their combination or placebo. The sensory...... gating paradigms in both experiments were identical. In humans, we found significantly reduced P50 suppression following separate administration of reboxetine or haloperidol, while their combined administration did not reach statistical significance compared with placebo. In the rats, we found a similar...... significant reduction of sensory gating (N40) following treatment with haloperidol and the combination of haloperidol and reboxetine, but not with separate reboxetine treatment, compared with placebo. Our study indicates that even when experimental conditions are kept as similar as possible, direct human...

Predator-based psychosocial stress animal model of PTSD: Preclinical assessment of traumatic stress at cognitive, hormonal, pharmacological, cardiovascular and epigenetic levels of analysis.

Science.gov (United States)

Zoladz, Phillip R; Diamond, David M

2016-10-01

Research on post-traumatic stress disorder (PTSD) is faced with the challenge of understanding how a traumatic experience produces long-lasting detrimental effects on behavior and brain functioning, and more globally, how stress exacerbates somatic disorders, including cardiovascular disease. Moreover, the design of translational research needs to link animal models of PTSD to clinically relevant risk factors which address why only a subset of traumatized individuals develop persistent psychopathology. In this review, we have summarized our psychosocial stress rodent model of PTSD which is based on well-described PTSD-inducing risk factors, including a life-threatening experience, a sense of horror and uncontrollability, and insufficient social support. Specifically, our animal model of PTSD integrates acute episodes of inescapable exposure of immobilized rats to a predator with chronic daily social instability. This stress regimen produces PTSD-like effects in rats at behavioral, cognitive, physiological, pharmacological and epigenetic levels of analysis. We have discussed a recent extension of our animal model of PTSD in which stress exacerbated coronary pathology following an ischemic event, assessed in vitro. In addition, we have reviewed our research investigating pharmacological and non-pharmacological therapeutic strategies which may have value in clinical approaches toward the treatment of traumatized people. Overall, our translational approach bridges the gap between human and animal PTSD research to create a framework with which to enhance our understanding of the biological basis of trauma-induced pathology and to assess therapeutic approaches in the treatment of psychopathology. Copyright © 2016 Elsevier Inc. All rights reserved.

Ciguatoxins: Cyclic Polyether Modulators of Voltage-gated Iion Channel Function

Science.gov (United States)

Nicholson, Graham M.; Lewis, Richard J.

2006-01-01

Ciguatoxins are cyclic polyether toxins, derived from marine dinoflagellates, which are responsible for the symptoms of ciguatera poisoning. Ingestion of tropical and subtropical fin fish contaminated by ciguatoxins results in an illness characterised by neurological, cardiovascular and gastrointestinal disorders. The pharmacology of ciguatoxins is characterised by their ability to cause persistent activation of voltage-gated sodium channels, to increase neuronal excitability and neurotransmitter release, to impair synaptic vesicle recycling, and to cause cell swelling. It is these effects, in combination with an action to block voltage-gated potassium channels at high doses, which are believed to underlie the complex of symptoms associated with ciguatera. This review examines the sources, structures and pharmacology of ciguatoxins. In particular, attention is placed on their cellular modes of actions to modulate voltage-gated ion channels and other Na+-dependent mechanisms in numerous cell types and to current approaches for detection and treatment of ciguatera.

Ciguatoxins: Cyclic Polyether Modulators of Voltage-gated Iion Channel Function

Directory of Open Access Journals (Sweden)

Richard J. Lewis

2006-04-01

Full Text Available Ciguatoxins are cyclic polyether toxins, derived from marine dinoflagellates, which are responsible for the symptoms of ciguatera poisoning. Ingestion of tropical and subtropical fin fish contaminated by ciguatoxins results in an illness characterised by neurological, cardiovascular and gastrointestinal disorders. The pharmacology of ciguatoxins is characterised by their ability to cause persistent activation of voltage-gated sodium channels, to increase neuronal excitability and neurotransmitter release, to impair synaptic vesicle recycling, and to cause cell swelling. It is these effects, in combination with an action to block voltage-gated potassium channels at high doses, which are believed to underlie the complex of symptoms associated with ciguatera. This review examines the sources, structures and pharmacology of ciguatoxins. In particular, attention is placed on their cellular modes of actions to modulate voltage-gated ion channels and other Na+-dependent mechanisms in numerous cell types and to current approaches for detection and treatment of ciguatera.

Gate length scaling trends of drive current enhancement in CMOSFETs with dual stress overlayers and embedded-SiGe

International Nuclear Information System (INIS)

Flachowsky, S.; Wei, A.; Herrmann, T.; Illgen, R.; Horstmann, M.; Richter, R.; Salz, H.; Klix, W.; Stenzel, R.

2008-01-01

Strain engineering in MOSFETs using tensile nitride overlayer (TOL) films, compressive nitride overlayer (COL) films, and embedded-SiGe (eSiGe) is studied by extensive device experiments and numerical simulations. The scaling behavior was analyzed by gate length reduction down to 40 nm and it was found that drive current strongly depends on the device dimensions. The reduction of drain-current enhancement for short-channel devices can be attributed to two competing factors: shorter gate length devices have increased longitudinal and vertical stress components which should result in improved drain-currents. However, there is a larger degradation from external resistance as the gate length decreases, due to a larger voltage dropped across the external resistance. Adding an eSiGe stressor reduces the external resistance in the p-MOSFET, to the extent that the drive current improvement from COL continues to increase even down the shortest gate length studied. This is due to the reduced resistivity of SiGe itself and the SiGe valence band offset relative to Si, leading to a smaller silicide-active contact resistance. It demonstrates the advantage of combining eSiGe and COL, not only for increased stress, but also for parasitic resistance reduction to enable better COL drive current benefit

Improvement in gate bias stress instability of amorphous indium-gallium-zinc oxide thin-film transistors using microwave irradiation

Energy Technology Data Exchange (ETDEWEB)

Jo, Kwang-Won; Cho, Won-Ju, E-mail: chowj@kw.ac.kr [Department of Electronic Materials Engineering, Kwangwoon University, 447-1, Wolgye-dong, Nowon-gu, Seoul 139-701 (Korea, Republic of)

2014-11-24

In this study, we evaluated the effects of microwave irradiation (MWI) post-deposition-annealing (PDA) treatment on the gate bias stress instability of amorphous indium-gallium-zinc oxide thin-film transistors (a-IGZO TFTs) and compared the results with a conventional thermal annealing PDA treatment. The MWI-PDA-treated a-IGZO TFTs exhibited enhanced electrical performance as well as improved long-term stability with increasing microwave power. The positive turn-on voltage shift (ΔV{sub ON}) as a function of stress time with positive bias and varying temperature was precisely modeled on a stretched-exponential equation, suggesting that charge trapping is a dominant mechanism in the instability of MWI-PDA-treated a-IGZO TFTs. The characteristic trapping time and average effective barrier height for electron transport indicate that the MWI-PDA treatment effectively reduces the defects in a-IGZO TFTs, resulting in a superior resistance against gate bias stress.

Improvement in gate bias stress instability of amorphous indium-gallium-zinc oxide thin-film transistors using microwave irradiation

International Nuclear Information System (INIS)

Jo, Kwang-Won; Cho, Won-Ju

2014-01-01

In this study, we evaluated the effects of microwave irradiation (MWI) post-deposition-annealing (PDA) treatment on the gate bias stress instability of amorphous indium-gallium-zinc oxide thin-film transistors (a-IGZO TFTs) and compared the results with a conventional thermal annealing PDA treatment. The MWI-PDA-treated a-IGZO TFTs exhibited enhanced electrical performance as well as improved long-term stability with increasing microwave power. The positive turn-on voltage shift (ΔV ON ) as a function of stress time with positive bias and varying temperature was precisely modeled on a stretched-exponential equation, suggesting that charge trapping is a dominant mechanism in the instability of MWI-PDA-treated a-IGZO TFTs. The characteristic trapping time and average effective barrier height for electron transport indicate that the MWI-PDA treatment effectively reduces the defects in a-IGZO TFTs, resulting in a superior resistance against gate bias stress

Rat Aquaporin-5 Is pH-Gated Induced by Phosphorylation and Is Implicated in Oxidative Stress

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Claudia Rodrigues

2016-12-01

Full Text Available Aquaporin-5 (AQP5 is a membrane water channel widely distributed in human tissues that was found up-regulated in different tumors and considered implicated in carcinogenesis in different organs and systems. Despite its wide distribution pattern and physiological importance, AQP5 short-term regulation was not reported and mechanisms underlying its involvement in cancer are not well defined. In this work, we expressed rat AQP5 in yeast and investigated mechanisms of gating, as well as AQP5’s ability to facilitate H2O2 plasma membrane diffusion. We found that AQP5 can be gated by extracellular pH in a phosphorylation-dependent manner, with higher activity at physiological pH 7.4. Moreover, similar to other mammalian AQPs, AQP5 is able to increase extracellular H2O2 influx and to affect oxidative cell response with dual effects: whereas in acute oxidative stress conditions AQP5 induces an initial higher sensitivity, in chronic stress AQP5 expressing cells show improved cell survival and resistance. Our findings support the involvement of AQP5 in oxidative stress and suggest AQP5 modulation by phosphorylation as a novel tool for therapeutics.

Degradation mechanism of enhancement-mode AlGaN/GaN HEMTs using fluorine ion implantation under the on-state gate overdrive stress

International Nuclear Information System (INIS)

Sun Wei-Wei; Zheng Xue-Feng; Fan Shuang; Wang Chong; Du Ming; Zhang Kai; Mao Wei; Zhang Jin-Cheng; Hao Yue; Chen Wei-Wei; Cao Yan-Rong; Ma Xiao-Hua

2015-01-01

The degradation mechanism of enhancement-mode AlGaN/GaN high electron mobility transistors (HEMTs) fabricated by fluorine plasma ion implantation technology is one major concern of HEMT’s reliability. It is observed that the threshold voltage shows a significant negative shift during the typical long-term on-state gate overdrive stress. The degradation does not originate from the presence of as-grown traps in the AlGaN barrier layer or the generated traps during fluorine ion implantation process. By comparing the relationships between the shift of threshold voltage and the cumulative injected electrons under different stress conditions, a good agreement is observed. It provides direct experimental evidence to support the impact ionization physical model, in which the degradation of E-mode HEMTs under gate overdrive stress can be explained by the ionization of fluorine ions in the AlGaN barrier layer by electrons injected from 2DEG channel. Furthermore, our results show that there are few new traps generated in the AlGaN barrier layer during the gate overdrive stress, and the ionized fluorine ions cannot recapture the electrons. (paper)

Experimental investigation of localized stress-induced leakage current distribution in gate dielectrics using array test circuit

Science.gov (United States)

Park, Hyeonwoo; Teramoto, Akinobu; Kuroda, Rihito; Suwa, Tomoyuki; Sugawa, Shigetoshi

2018-04-01

Localized stress-induced leakage current (SILC) has become a major problem in the reliability of flash memories. To reduce it, clarifying the SILC mechanism is important, and statistical measurement and analysis have to be carried out. In this study, we applied an array test circuit that can measure the SILC distribution of more than 80,000 nMOSFETs with various gate areas at a high speed (within 80 s) and a high accuracy (on the 10-17 A current order). The results clarified that the distributions of localized SILC in different gate areas follow a universal distribution assuming the same SILC defect density distribution per unit area, and the current of localized SILC defects does not scale down with the gate area. Moreover, the distribution of SILC defect density and its dependence on the oxide field for measurement (E OX-Measure) were experimentally determined for fabricated devices.

Assessment of left ventricular function by electrocardiogram-gated myocardial single photon emission computed tomography using quantitative gated single photon emission computed tomography software

International Nuclear Information System (INIS)

Morita, Koichi; Adachi, Itaru; Konno, Masanori

1999-01-01

Electrocardiogram (ECG)-gated myocardial single photon emission computed tomography (SPECT) can assess left ventricular (LV) perfusion and function easily using quantitative gated SPECT (QGS) software. ECG-gated SPECT was performed in 44 patients with coronary artery disease under post-stress and resting conditions to assess the values of LV functional parameters, by comparison to LV ejection fraction derived from gated blood pool scan and myocardial characteristics. A good correlation was obtained between ejection fraction using QGS and that using cardiac blood pool scan (r=0.812). Some patients with myocardial ischemia had lower ejection fraction under post-stress compared to resting conditions, indicating post-stress LV dysfunction. LV wall motion and wall thickening were significantly impaired in ischemic and infarcted myocardium, and the degree of abnormality in the infarcted areas was greater than in the ischemia area. LV functional parameters derived using QGS were useful to assess post-stress LV dysfunction and myocardial viability. In conclusion, ECG-gated myocardial SPECT permits simultaneous quantitative assessment of myocardial perfusion and function. (author)

The gate oxide integrity of CVD tungsten polycide

International Nuclear Information System (INIS)

Wu, N.W.; Su, W.D.; Chang, S.W.; Tseng, M.F.

1988-01-01

CVD tungsten polycide has been demonstrated as a good gate material in recent very large scale integration (VLSI) technology. CVD tungsten silicide offers advantages of low resistivity, high temperature stability and good step coverage. On the other hand, the polysilicon underlayer preserves most characteristics of the polysilicon gate and acts as a stress buffer layer to absorb part of the thermal stress origin from the large thermal expansion coefficient of tungsten silicide. Nevertheless, the gate oxide of CVD tungsten polycide is less stable or reliable than that of polysilicon gate. In this paper, the gate oxide integrity of CVD tungsten polycide with various thickness combinations and different thermal processes have been analyzed by several electrical measurements including breakdown yield, breakdown fluence, room temperature TDDB, I-V characteristics, electron traps and interface state density

Magnetic resonance pharmacological stress for detecting coronary disease. Comparison with echocardiography

Energy Technology Data Exchange (ETDEWEB)

Baer, F.M.; Crnac, J.; Jochims, M.; Schneider, C.; Erdmann, E. [Clinic III of Internal Medicine, Univ. of Cologne (Germany); Schmidt, M.; Theissen, P.; Schicha, H. [Clinic und Ambulant Clinic of Nuclear Medicine, Univ. of Cologne (Germany)

2000-06-01

Stress testing is the cornerstone in the diagnosis of patients with suspected coronary artery disease (CAD). Although exercise ECG remains the primary approach for the detection of ischemia in patients with chest pain syndromes, its sensitivity and specificity is limited and exercise ECG does not provide detailed information about the localisation and extent of CAD. Stress echocardiography has been used for the detection of ischemia for more than a decade and has become an increasingly popular noninvasive method for the detection of CAD. In experienced hands wall motion analysis based on stress echocardiography has proved to be as sensitive and specific for the detection of myocardial ischemia as scintigraphic techniques. Recent technical improvements, namely the availability of ultrafast imaging sequences with a significant reduction of imaging time have initiated several studies which examined the combination of pharmacological stress and magnetic resonance imaging (MRI) for the detection of suspected CAD. The most well developed stress-MRI technique is wall motion imaging during dobutamine stress. This technique is analogous to stress echocardiography, but MRI has the inherent advantages of better resolution, higher reproducibility and true long and short axis imaging with contiguous parallel slices. However, the clinical impact of MRI for the diagnosis of CAD is still low. Further technical developments including real time imaging and a reliable automated quantitative analysis of left ventricular function are required before stress-MRI becomes a serious challenge to stressechocardiography in the clinical arena. Currently, only a few MRI facilities and physicians are dedicated to pharmacological stress testing with MRI and the future clinical impact of this promising technique will depend on its potential to provide information beyond myocardial function including perfusion, metabolism and coronary anatomy in form of a ''one-stop''-shop for

Molecular doping for control of gate bias stress in organic thin film transistors

Energy Technology Data Exchange (ETDEWEB)

Hein, Moritz P., E-mail: hein@iapp.de; Lüssem, Björn; Jankowski, Jens; Tietze, Max L.; Riede, Moritz K. [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden (Germany); Zakhidov, Alexander A. [Fraunhofer COMEDD, Maria-Reiche-Str. 2, 01109 Dresden (Germany); Leo, Karl [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden (Germany); Fraunhofer COMEDD, Maria-Reiche-Str. 2, 01109 Dresden (Germany)

2014-01-06

The key active devices of future organic electronic circuits are organic thin film transistors (OTFTs). Reliability of OTFTs remains one of the most challenging obstacles to be overcome for broad commercial applications. In particular, bias stress was identified as the key instability under operation for numerous OTFT devices and interfaces. Despite a multitude of experimental observations, a comprehensive mechanism describing this behavior is still missing. Furthermore, controlled methods to overcome these instabilities are so far lacking. Here, we present the approach to control and significantly alleviate the bias stress effect by using molecular doping at low concentrations. For pentacene and silicon oxide as gate oxide, we are able to reduce the time constant of degradation by three orders of magnitude. The effect of molecular doping on the bias stress behavior is explained in terms of the shift of Fermi Level and, thus, exponentially reduced proton generation at the pentacene/oxide interface.

Molecular doping for control of gate bias stress in organic thin film transistors

International Nuclear Information System (INIS)

Hein, Moritz P.; Lüssem, Björn; Jankowski, Jens; Tietze, Max L.; Riede, Moritz K.; Zakhidov, Alexander A.; Leo, Karl

2014-01-01

The key active devices of future organic electronic circuits are organic thin film transistors (OTFTs). Reliability of OTFTs remains one of the most challenging obstacles to be overcome for broad commercial applications. In particular, bias stress was identified as the key instability under operation for numerous OTFT devices and interfaces. Despite a multitude of experimental observations, a comprehensive mechanism describing this behavior is still missing. Furthermore, controlled methods to overcome these instabilities are so far lacking. Here, we present the approach to control and significantly alleviate the bias stress effect by using molecular doping at low concentrations. For pentacene and silicon oxide as gate oxide, we are able to reduce the time constant of degradation by three orders of magnitude. The effect of molecular doping on the bias stress behavior is explained in terms of the shift of Fermi Level and, thus, exponentially reduced proton generation at the pentacene/oxide interface

VKCDB: Voltage-gated potassium channel database

Directory of Open Access Journals (Sweden)

Gallin Warren J

2004-01-01

Full Text Available Abstract Background The family of voltage-gated potassium channels comprises a functionally diverse group of membrane proteins. They help maintain and regulate the potassium ion-based component of the membrane potential and are thus central to many critical physiological processes. VKCDB (Voltage-gated potassium [K] Channel DataBase is a database of structural and functional data on these channels. It is designed as a resource for research on the molecular basis of voltage-gated potassium channel function. Description Voltage-gated potassium channel sequences were identified by using BLASTP to search GENBANK and SWISSPROT. Annotations for all voltage-gated potassium channels were selectively parsed and integrated into VKCDB. Electrophysiological and pharmacological data for the channels were collected from published journal articles. Transmembrane domain predictions by TMHMM and PHD are included for each VKCDB entry. Multiple sequence alignments of conserved domains of channels of the four Kv families and the KCNQ family are also included. Currently VKCDB contains 346 channel entries. It can be browsed and searched using a set of functionally relevant categories. Protein sequences can also be searched using a local BLAST engine. Conclusions VKCDB is a resource for comparative studies of voltage-gated potassium channels. The methods used to construct VKCDB are general; they can be used to create specialized databases for other protein families. VKCDB is accessible at http://vkcdb.biology.ualberta.ca.

Prognostic implications of post-stress ejection fraction decrease detected by gated SPECT in the absence of stress-induced perfusion abnormalities

Energy Technology Data Exchange (ETDEWEB)

Dona, Manjola; Massi, Lucia; Settimo, Leonardo; Bartolini, Matteo; Gianni, Gianluca; Pupi, Alberto; Sciagra, Roberto [University of Florence, Nuclear Medicine Unit, Department of Clinical Physiopathology, Florence (Italy)

2011-03-15

The prognostic meaning of a post-stress ejection fraction (EF) decrease detected by perfusion gated SPECT is still unclear. We therefore followed up patients with post-stress EF decrease in the absence of stress-induced perfusion abnormalities. We prospectively enrolled 57 consecutive patients with post-stress EF drop {>=} 5 EF units and summed difference score (SDS) {<=} 1. They were followed up for more than 1 year and their outcome was compared with a group of sex- and age-matched controls with the same SDS but without EF decrease. During follow-up there were 13 events (1 cardiac death, 1 non-fatal myocardial infarction, 1 congestive heart failure and 10 late revascularizations). In the control group we registered six events. There was a significant difference (p < 0.0001) between the event-free survival curves of the two groups. The event rate of patients with post-stress EF decrease {>=} 5 EF units is relatively high and is significantly worse than that of a control group of patients with similarly normal SDS but without EF changes. Therefore, a post-stress EF decrease without stress-induced perfusion abnormalities should be cautiously interpreted. (orig.)

Human studies of prepulse inhibition of startle: normal subjects, patient groups, and pharmacological studies.

Science.gov (United States)

Braff, D L; Geyer, M A; Swerdlow, N R

2001-07-01

, blepharospasm, temporal lobe epilepsy with psychosis, enuresis, and perhaps posttraumatic stress disorder (PTSD). Several pharmacological manipulations have been examined for their effects on PPI in healthy human subjects. In some cases, the alterations in PPI produced by these drugs in animals correspond to similar effects in humans. Specifically, dopamine agonists disrupt and nicotine increases PPI in at least some human studies. With some other compounds, however, the effects seen in humans appear to differ from those reported in animals. For example, the PPI-increasing effects of the glutamate antagonist ketamine and the serotonin releaser MDMA in humans are opposite to the PPI-disruptive effects of these compounds in rodents. Considerable evidence supports a high degree of homology between measures of PPI in rodents and humans, consistent with the use of PPI as a cross-species measure of sensorimotor gating. Multiple investigations of PPI using a variety of methods and parameters confirm that deficits in PPI are evident in schizophrenia-spectrum patients and in certain other disorders in which gating mechanisms are disturbed. In contrast to the extensive literature on clinical populations, much more work is required to clarify the degree of correspondence between pharmacological effects on PPI in healthy humans and those reported in animals.

The Effect of Non-Pharmacological Methods of Labor Pain Relief on Mothers’ Perceived Stress: ARandomized Controlled Trial

Directory of Open Access Journals (Sweden)

Mojghan Mirghafourvand

2014-12-01

Full Text Available Background & objectives: Childbirth is the most stressful event for the women both mentally and physically affecting their physiological and psychological indicators during labour. The aim of this study was to assess the effect of non-pharmacological methods of labor pain relief in mothers’ perceived stress conducted in Alavi hospital of Ardabil, 2013.  Methods: In this double blind randomized controlled trial, 320 mothers were allocated into two groups by stratified block randomization . The intervention group (n=158 received continuous support throughout the labour process, positioning and movement, music, aromatherapy, showering andconsumption of a light diet or water.The control group received only a routine care. The perceived stress scale (PSS was employed to collect data in three stages at the beginning of the active phase, before the intervention, six hours after birth and then eight weeks postpartum. The two groupswere compared using General Linear Model with controlling the baseline scores. Results: There were 14 participants loss to follow-up. The mean of perceived stress score in the intervention group was significantly lower than the control group at 6 hours [adjusted mean difference: -1.0 (95% confidence interval: -0.01 to -1.9]. However, there was no difference between two groups in terms of perceived stress score at 8 weeks postpartum (p=0.692.  Conclusion: Non-pharmacological methods of labor pain relief are an effective intervention for reducing perceived stress level in mothers during labor and therefore use of this intervention is recommended.

Effect of incorporation of nitrogen atoms in Al2O3 gate dielectric of wide-bandgap-semiconductor MOSFET on gate leakage current and negative fixed charge

Science.gov (United States)

Kojima, Eiji; Chokawa, Kenta; Shirakawa, Hiroki; Araidai, Masaaki; Hosoi, Takuji; Watanabe, Heiji; Shiraishi, Kenji

2018-06-01

We performed first-principle calculations to investigate the effect of incorporation of N atoms into Al2O3 gate dielectrics. Our calculations show that the defect levels generated by VO in Al2O3 are the origin of the stress-induced gate leakage current and that VOVAl complexes in Al2O3 cause negative fixed charge. We revealed that the incorporation of N atoms into Al2O3 eliminates the VO defect levels, reducing the stress-induced gate leakage current. Moreover, this suppresses the formation of negatively charged VOVAl complexes. Therefore, AlON can reduce both stress-induced gate leakage current and negative fixed charge in wide-bandgap-semiconductor MOSFETs.

Influence of white light illumination on the performance of a-IGZO thin film transistor under positive gate-bias stress

Science.gov (United States)

Tang, Lan-Feng; Yu, Guang; Lu, Hai; Wu, Chen-Fei; Qian, Hui-Min; Zhou, Dong; Zhang, Rong; Zheng, You-Dou; Huang, Xiao-Ming

2015-08-01

The influence of white light illumination on the stability of an amorphous InGaZnO thin film transistor is investigated in this work. Under prolonged positive gate bias stress, the device illuminated by white light exhibits smaller positive threshold voltage shift than the device stressed under dark. There are simultaneous degradations of field-effect mobility for both stressed devices, which follows a similar trend to that of the threshold voltage shift. The reduced threshold voltage shift under illumination is explained by a competition between bias-induced interface carrier trapping effect and photon-induced carrier detrapping effect. It is further found that white light illumination could even excite and release trapped carriers originally exiting at the device interface before positive gate bias stress, so that the threshold voltage could recover to an even lower value than that in an equilibrium state. The effect of photo-excitation of oxygen vacancies within the a-IGZO film is also discussed. Project supported by the State Key Program for Basic Research of China (Grant Nos. 2011CB301900 and 2011CB922100) and the Priority Academic Program Development of Jiangsu Higher Education Institutions, China.

Stress-induced myocardial ischemia is associated with early post-stress left ventricular mechanical dyssynchrony as assessed by phase analysis of {sup 201}Tl gated SPECT myocardial perfusion imaging

Energy Technology Data Exchange (ETDEWEB)

Chen, Chien-Cheng; Shen, Thau-Yun [Show Chwan Memorial Hospital, Department of Cardiology, Changhua (China); Chang, Ming-Che [Changhua Christian Hospital, Department of Nuclear Medicine, Changhua (China); Hung, Guang-Uei [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Changhua (China); China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China); Chen, Wan-Chen [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Changhua (China); Kao, Chia-Hung [China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China); Chen, Ji [Emory University School of Medicine, Department of Radiology and Imaging Sciences, Atlanta, GA (United States)

2012-12-15

In {sup 201}Tl SPECT myocardial perfusion imaging (MPI) data are acquired shortly after the stress injection to assess early post-stress left ventricle (LV) function. The purpose of this study was to use {sup 201}Tl SPECT MPI to investigate whether stress-induced myocardial ischemia is associated with LV mechanical dyssynchrony. Enrolled in the study were 75 patients who were referred for dipyridamole stress and rest {sup 201}Tl gated SPECT MPI. The early post-stress scan was started 5 min after injection, and followed by the rest scan 4 h later. The patients were divided into three groups: ischemia group (N = 25, summed stress score, SSS, {>=}5, summed rest score, SRS, <5), infarct group (N = 16, SSS {>=}5, SRS {>=}5) and normal group (N = 34, SSS <5, SRS <5). LV dyssynchrony parameters were calculated by phase analysis, and compared between the stress and rest images. In the ischemia group, LV dyssynchrony was significantly larger during stress than during rest. On the contrary, LV dyssynchrony during stress was significantly smaller than during rest in the normal and infarct groups. LV dyssynchrony during rest was significantly larger in the infarct group than in the normal and ischemia groups. There were no significant differences in LV dyssynchrony during rest between the normal and ischemia groups. Stress-induced myocardial ischemia caused dyssynchronous contraction in the ischemic region, leading to a deterioration in LV synchrony. Normal myocardium had more synchronous contraction during stress. The different dyssynchrony pattern between ischemic and normal myocardium early post-stress may aid the diagnosis of coronary artery disease using {sup 201}Tl gated SPECT MPI. (orig.)

Hemodynamic effects of a novel pharmacologic stress agent, Higemine

International Nuclear Information System (INIS)

Zhang, X.L.; Liu, X.J.; Tao, Z.H.; Shi, R.F.

2002-01-01

Objective: Higenamine (dl-demethylcodaurine) (HG), which was isolated from aconitum japonicum. This study was to evaluate the hemodynamic effects of HG in animal study. Methods: We compared the hemodynamic effects of HG (0.5-4μg/min/kg) with Dobutamine (Dob) (5-30μg/min/kg) in 6 dogs: heart rate (HR), blood pressure (BP), coronary blood flow (CBF), myocardial oxygen consumption (MOC) were measured. Tolerability and safety of HG (1-500μg/mg/min) were evaluated in 8 dogs. Results: Comparison of hemodynamic effects between Dob an HG was presented. SBP: systolic blood pressure; DP: diastolic blood pressure; P<0.01; P<0.05. Diastolic BP slightly decreased, but systolic BP did not change significantly during HG infusion. There was no significant ECG abnormalities and side effects during HG infusion. Conclusion: HG might be a safe and useful pharmacologic stress agent, especially for patients with severe hypertension

Resting electrocardiogram and stress myocardial perfusion imaging in the determination of left ventricular systolic function: an assessment enhancing the performance of gated SPET.

Science.gov (United States)

Moralidis, Efstratios; Spyridonidis, Tryfon; Arsos, Georgios; Skeberis, Vassilios; Anagnostopoulos, Constantinos; Gavrielidis, Stavros

2010-01-01

This study aimed to determine systolic dysfunction and estimate resting left ventricular ejection fraction (LVEF) from information collected during routine evaluation of patients with suspected or known coronary heart disease. This approach was then compared to gated single photon emission tomography (SPET). Patients having undergone stress (201)Tl myocardial perfusion imaging followed by equilibrium radionuclide angiography (ERNA) were separated into derivation (n=954) and validation (n=309) groups. Logistic regression analysis was used to develop scoring systems, containing clinical, electrocardiographic (ECG) and scintigraphic data, for the discrimination of an ERNA-LVEFstatistic (mean+/-2SD) provided values of 0.001+/-0.176, 0.071+/-0.196 and 0.040+/-0.152, respectively. The average LVEF was a better discriminator of systolic dysfunction than gated SPET-LVEF in receiver operating characteristic (ROC) analysis and identified more patients (89%) with a stress myocardial perfusion imaging variables. This model provides reliable LVEF estimations, comparable to those from (201)Tl gated SPET, and can enhance the clinical performance of the latter.

Assessment of ischemic heart disease by dipyridamole stress electrocardiographic gated myocardial single photon emission computed tomography with technetium-99m tetrofosmin

International Nuclear Information System (INIS)

Kanna, Masahiko; Mitani, Isao; Nakamaru, Masashi; Shibuya, Ken; Takeda, Kazuyoshi; Asahina, Shigeru; Kitamura, Yutaka; Higuma, Kikuhiko; Ishii, Masao

1998-01-01

Simultaneous assessment of stress perfusion and rest function is possible with gated single photon emission computed tomography (SPECT) using stress injected technetium-99m ( 99m Tc) tetrofosmin (TF). The feasibility of dipyridamole stress electrocardiographic gated myocardial SPECT (GSPECT) with TF was examined as an alternative to conventional stress/rest imaging. Fifty-one patients underwent stress GSPECT. 740 MBq of TF was administered 3 min after dipyridamole infusion. GSPECT acquisition was performed one hour after the injection. Additional rest SPECT was performed on another day only in patients with abnormal perfusion on stress images. Perfusion and thickening were analyzed visually on 17 segments of the left ventricle. Percentage of wall thickening (%WT) was also calculated in 17 segments of the polar map. Thirty-two of 51 patients (63%) had normal stress perfusion and normal rest thickening. Nineteen of 51 patients (37%) had abnormal perfusion on stress images. Among 157 abnormal perfusion segments of the 19 patients, 139 segments (89%) had thickening and the rest (11%) had no thickening. %WT was higher in the reversible segments with or without thickening. There was better agreement for the identification of normal segments and the presence of reversibility between stress GSPECT and the conventional stress/rest study in patients without previous myocardial infarction than in those with previous myocardial infarction (89% vs 79%). These results suggest that stress GSPECT may substitute for conventional stress/rest perfusion study in patients without previous myocardial infarction, allowing shorter examination time and lower cost. However, stress GSPECT does not replace the need for rest perfusion study in patients with previous myocardial infarction, because of underestimation of viability, but %WT may eliminate this underestimation. (author)

Reversible wall motion abnormality on adenosine stress/rest thallium-201 gated myocardial SPECT is an independent predictor of coronary artery disease

International Nuclear Information System (INIS)

Park, Eun Kyung; Lee, Won Woo; So, Young; Eo, Jae Seon; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul; Kim, Sang Eun; Kim, Cheol Ho; Lee, Sang Woo

2004-01-01

As early as 10 minutes after adenosine stress, immediate post-stress wall motion (ipsWM) can be evaluated on adenosine stress/rest TI-201 gated SPECT (gSPECT). To widen application of TI-201 in gated SPECT, we investigated image quality, LV parameters (EF, EDV, and ESV) reproducibility, and diagnostic competency of gSPECT regarding ipsWM evaluation Myocardial perfusion and wall motion were evaluated by 5-point scoring system in 20-segment model. Image quality was assessed using weighted Kappa (Kw) for inter-and intra-observer agreements of wall motion scores (n=49). Reproducibility was examined through repeated acquisition (n=31). Diagnostic competency was evaluated versus coronary angiography (CAG) and multivariate logistic regression analysis was performed to identify significant predictors of coronary artery disease (CAD) among stress abnormal perfusion (SSSp), stress abnormal wall motion (SSSwm), and reversible abnormal wall motion (SDSwm) (n=60). Kw for ipsWM was significantly better than that for rest regarding inter- (0.717 vs 0.489) and intra-observer agreements (0.792 vs 0.688) (p<0.05). 2SD for ipsWM was smaller than that for rest at EF (8.6% vs 10.7%) and ESV (6.0ml vs 8.4ml). Sensitivities of SSSp, SSSwm, and SDSwm were 63.3% (19/30), 63.3% (19/30), and 43.3% (13/30) and specificities 83.3% (25/30), 83.3% (25/30), and 86.7% (26/30), respectively. By multivariate analysis, SSSp (p=0.013) and SDSwm (p=0.039) remained significant predictors. Additionally, SSSwm or SDSwm could find undetected CAD in 54.5% (6/11) of patients with normal perfusion. TI-201 can be successfully applied to gated SPECT for ipsWM evaluation. Moreover, reversible wall motion abnormality on gSPECT is an independent predictor of significant CAD

Combination of physical exercise and adenosine improves accuracy of automatic calculation of stress LVEF in gated SPECT using QGS software

International Nuclear Information System (INIS)

Tehranipour, N.; AL-Nahhas, A.; Towey, D.

2005-01-01

Combining exercise and adenosine during the stress phase of myocardial perfusion imaging (MPI) is known to reduce adverse effects and improve image quality. The aim of this study was to assess whether it can also improve the automatic calculation of left ventricular ejection fraction (LVEF) by QGS software package, during the stress phase of Gated SPECT. One hundred patients who had stress Gated SPECT were retrospectively included in this study. Gated data of those who had adenosine only (50 patients = group A) was compared with those obtained in another group of 50 patients who had added bicycle exercise (Group B). All had identical image acquisition protocol using 99mT c-tetrofosmine. Clinical adverse effects, changes in blood pressure (BP), heart rate (HR), and ECG were monitored. Visual assessment of subdiaphragmatic uptake and accuracy of automatic regions of interest (ROI's) drawn by the software were noted. Regions of interest that involved sub-diaphragmatic uptake and resulting in low LVEF were manually adjusted to include the left ventricle only, and the frequency of manual adjustment was noted. No significant difference was noted in age, sex, baseline BP and HR between groups A and B. Adverse effects occurred less often in group B compared to group A (12% vs. 24%, p = 0.118). Maximum HR and BP achieved during stress were significantly higher in group B compared to group A (p 0.025, p = 0.001 respectively). The number of patients who had faulty ROI's and low LVEF, who needed manual adjustment of ROI.s, were higher in group A compared to group B (16% vs. 6%, p = 0.025). The values of LVEF showed significant improvement following manual adjustment of ROI's, increasing from a mean of 19.63 ± 15.96 to 62.13 ± 7.55 (p = 0.0001) and from 17.33 ± 9.5 to 49.67 ± 7.7 (p = 0.0014) in groups A and B respectively. The addition of exercise to adenosine significantly improves the automatic calculation of LVEF by QGS software during Gated SPECT and reduces the need

Gated single photon emission computer tomography for the detection of silent myocardial ischemia

International Nuclear Information System (INIS)

Pena Q, Yamile; Coca P, Marco Antonio; Batista C, Juan Felipe; Fernandez-Britto, Jose; Quesada P, Rodobaldo; Pena C; Andria

2009-01-01

Background: Asymptomatic patients with severe coronary atherosclerosis may have a normal resting electrocardiogram and stress test. Aim: To assess the yield of Gated Single Photon Emission Computer Tomography (SPECT) for the screening of silent myocardial ischemia in type 2 diabetic patients. Material and methods: Electrocardiogram, stress test and gated-SPECT were performed on 102 type 2 diabetic patients aged 60 ± 8 years without cardiovascular symptoms. All subjects were also subjected to a coronary angiography, whose results were used as gold standard. Results: Gated-SPECT showed myocardial ischemia on 26.5% of studied patients. The sensibility, specificity, accuracy, positive predictive value and negative predictive value were 92.3%, 96%, 95%, 88.8%, 97.3%, respectively. In four and six patients ischemia was detected on resting electrocardiogram and stress test, respectively. Eighty percent of patients with doubtful resting electrocardiogram results and 70% with a doubtful stress test had a silent myocardial ischemia detected by gated-SPECT. There was a good agreement between the results of gated-SPECT and coronary angiography (k =0.873). Conclusions: Gated-SPECT was an useful tool for the screening of silent myocardial ischemia

Recent Pharmacology Studies on the International Space Station

Science.gov (United States)

Wotring, Virginia

2014-01-01

The environment on the International Space Station (ISS) includes a variety of potential stressors including the absence of Earth's gravity, elevated exposure to radiation, confined living and working quarters, a heavy workload, and high public visibility. The effects of this extreme environment on pharmacokinetics, pharmacodynamics, and even on stored medication doses, are not yet understood. Dr. Wotring will discuss recent analyses of medication doses that experienced long duration storage on the ISS and a recent retrospective examination of medication use during long-duration spaceflights. She will also describe new pharmacology experiments that are scheduled for upcoming ISS missions. Dr. Virginia E. Wotring is a Senior Scientist in the Division of Space Life Sciences in the Universities Space Research Association, and Pharmacology Discipline Lead at NASA's Johnson Space Center, Human Heath and Countermeasures Division. She received her doctorate in Pharmacological and Physiological Science from Saint Louis University after earning a B.S. in Chemistry at Florida State University. She has published multiple studies on ligand gated ion channels in the brain and spinal cord. Her research experience includes drug mechanisms of action, drug receptor structure/function relationships and gene & protein expression. She joined USRA (and spaceflight research) in 2009. In 2012, her book reviewing pharmacology in spaceflight was published by Springer: Space Pharmacology, Space Development Series.

Diagnosis of severe and extensive coronary artery disease using gated myocardial perfusion SPECT

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Cho, Ihn Ho; Lee, Hyoung Woo; Won, Kyu Chang; Park, Jong Sun; Sin, Dog Gu; Kim, Young Jo; Shim, Bong Sub [College of Medicine, Yeungnam Univ., Taegu (Korea, Republic of)

1999-07-01

Left ventricular volumes and ejection fractions constitute important informations in the diagnosis and prognosis of cardiac disease. Aim of the study is to verify if the assessment of left ventricular function and perfusion together by gated myocardial perfusion SPECT is useful for diagnosing severe and extensive CAD. We examined 27 consecutive patients (17 males and 10 females, mean age : 60.1 years) who underwent two day rest/stress Tc-99m MIBI gated SPECT. Stress was done with adenosine. Post-stress gated SPECT was done at 1 hour after an injection of Tc-99m MIBI (740 MBq). All patients underwent coronary angiography after gated SPECT within 1 month. We divided them three groups with single vessel disease, double vessel disease and triple vessel disease or severe proximal left coronary artery stenosis. Extent of Defect (ED), Reversibility of Extent (RE), Severity of Defect (SD) and Severity of Reversibility (SR) were calculated by CEqual program. Post-stress LVEF, Rest LVEF, End-diastolic volume(EDV), End-systolic volume(ESV), Transient Ischemic Dilation (TID) of left ventricle (Post-stress EDV/Rest EDV) were calculated using gated SPECT quantification program. Left ventricle is divided with 18 segments and wall motion was scored (normal=0, mild hypokinesia =1, severe hypokinesia =2, akinesia =3 and dyskinesia =4), and then post-stress summed wall motion score was calculated. Post-stress summed wall motion score and post-stress LVEF were significant differences between three groups ( P <0.01). Extent of defect, Extent of reversibility, Severity of defect and severity of reversibility in Polar map were significant differences between three groups ( P <0.01). Post-stress Transient left ventricular dilatation and test LVEF were not significant differences between three groups ( P > 0.05). The gated SPECT pattern (low post-stress LVEF and post-stress summed wall motion score) add important diagnostic information over ungated perfusion data (high ED, ER and SR and

Investigation of the gate-bias induced instability for InGaZnO TFTs under dark and light illumination

International Nuclear Information System (INIS)

Chen, T.C.; Chang, T.C.; Hsieh, T.Y.; Tsai, C.T.; Chen, S.C.; Lin, C.S.; Jian, F.Y.; Tsai, M.Y.

2011-01-01

Mechanism of the instability for indium–gallium–zinc oxide thin film transistors caused by gate-bias stress performed in the dark and light illumination was investigated in this paper. The parallel V t shift with no degradation of subthreshold swing (S.S) and the fine fitting to the stretched-exponential equation indicate that charge trapping model dominates the degradation behavior under positive gate-bias stress. In addition, the significant gate-bias dependence of V t shift demonstrates that electron trapping effect easily occurs under large gate-bias since the average effective energy barrier of electron injection decreases with increasing gate bias. Moreover, the noticeable decrease of threshold voltage (V t ) shift under illuminated positive gate-bias stress and the accelerated recovery rate in the light indicate that the charge detrapping mechanism occurs under light illumination. Finally, the apparent negative V t shift under illuminated negative gate-bias stress was investigated in this paper. The average effectively energy barrier of electron and hole injection were extracted to clarify that the serious V t degradation behavior comparing with positive gate-bias stress was attributed to the lower energy barrier for hole injection.

Voltage-Gated Calcium Channels

Science.gov (United States)

Zamponi, Gerald Werner

Voltage Gated Calcium Channels is the first comprehensive book in the calcium channel field, encompassing over thirty years of progress towards our understanding of calcium channel structure, function, regulation, physiology, pharmacology, and genetics. This book balances contributions from many of the leading authorities in the calcium channel field with fresh perspectives from risings stars in the area, taking into account the most recent literature and concepts. This is the only all-encompassing calcium channel book currently available, and is an essential resource for academic researchers at all levels in the areas neuroscience, biophysics, and cardiovascular sciences, as well as to researchers in the drug discovery area.

Functional characterization of neurotransmitter activation and modulation in a nematode model ligand-gated ion channel.

Science.gov (United States)

Heusser, Stephanie A; Yoluk, Özge; Klement, Göran; Riederer, Erika A; Lindahl, Erik; Howard, Rebecca J

2016-07-01

The superfamily of pentameric ligand-gated ion channels includes neurotransmitter receptors that mediate fast synaptic transmission in vertebrates, and are targets for drugs including alcohols, anesthetics, benzodiazepines, and anticonvulsants. However, the mechanisms of ion channel opening, gating, and modulation in these receptors leave many open questions, despite their pharmacological importance. Subtle conformational changes in both the extracellular and transmembrane domains are likely to influence channel opening, but have been difficult to characterize given the limited structural data available for human membrane proteins. Recent crystal structures of a modified Caenorhabditis elegans glutamate-gated chloride channel (GluCl) in multiple states offer an appealing model system for structure-function studies. However, the pharmacology of the crystallographic GluCl construct is not well established. To establish the functional relevance of this system, we used two-electrode voltage-clamp electrophysiology in Xenopus oocytes to characterize activation of crystallographic and native-like GluCl constructs by L-glutamate and ivermectin. We also tested modulation by ethanol and other anesthetic agents, and used site-directed mutagenesis to explore the role of a region of Loop F which was implicated in ligand gating by molecular dynamics simulations. Our findings indicate that the crystallographic construct functionally models concentration-dependent agonism and allosteric modulation of pharmacologically relevant receptors. Specific substitutions at residue Leu174 in loop F altered direct L-glutamate activation, consistent with computational evidence for this region's role in ligand binding. These insights demonstrate conservation of activation and modulation properties in this receptor family, and establish a framework for GluCl as a model system, including new possibilities for drug discovery. In this study, we elucidate the validity of a modified glutamate-gated

Assessment of poststress left ventricular ejection fraction by gated SPECT: comparison with equilibrium radionuclide angiocardiography

International Nuclear Information System (INIS)

Acampa, Wanda; Liuzzi, Raffaele; De Luca, Serena; Capasso, Enza; Luongo, Luca; Cuocolo, Alberto; Caprio, Maria Grazia; Nicolai, Emanuele; Petretta, Mario

2010-01-01

We compared left ventricular (LV) ejection fraction obtained by gated SPECT with that obtained by equilibrium radionuclide angiocardiography in a large cohort of patients. Within 1 week, 514 subjects with suspected or known coronary artery disease underwent same-day stress-rest 99m Tc-sestamibi gated SPECT and radionuclide angiocardiography. For both studies, data were acquired 30 min after completion of exercise and after 3 h rest. In the overall study population, a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.82, p<0.0001) and after stress (r=0.83, p<0.0001). In Bland-Altman analysis, the mean differences in ejection fraction (radionuclide angiocardiography minus gated SPECT) were -0.6% at rest and 1.7% after stress. In subjects with normal perfusion (n=362), a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.72, p<0.0001) and after stress (r=0.70, p<0.0001) and the mean differences in ejection fraction were -0.9% at rest and 1.4% after stress. Also in patients with abnormal perfusion (n=152), a good correlation between the two techniques was observed both at rest (r=0.89, p<0.0001) and after stress (r=0.90, p<0.0001) and the mean differences in ejection fraction were 0.1% at rest and 2.5% after stress. In a large study population, a good agreement was observed in the evaluation of LV ejection fraction between gated SPECT and radionuclide angiocardiography. However, in patients with perfusion abnormalities, a slight underestimation in poststress LV ejection fraction was observed using gated SPECT as compared to equilibrium radionuclide angiocardiography. (orig.)

A thermalization energy analysis of the threshold voltage shift in amorphous indium gallium zinc oxide thin film transistors under positive gate bias stress

Energy Technology Data Exchange (ETDEWEB)

Niang, K. M.; Flewitt, A. J., E-mail: ajf@eng.cam.ac.uk [Electrical Engineering Division, Cambridge University, J J Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Barquinha, P. M. C.; Martins, R. F. P. [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa and CEMOP/UNINOVA, Campus de Caparica, 2829-516 Caparica (Portugal); Cobb, B. [Holst Centre/TNO, High Tech Campus 31, 5656AE Eindhoven (Netherlands); Powell, M. J. [252, Valley Drive, Kendal LA9 7SL (United Kingdom)

2016-02-29

Thin film transistors (TFTs) employing an amorphous indium gallium zinc oxide (a-IGZO) channel layer exhibit a positive shift in the threshold voltage under the application of positive gate bias stress (PBS). The time and temperature dependence of the threshold voltage shift was measured and analysed using the thermalization energy concept. The peak energy barrier to defect conversion is extracted to be 0.75 eV and the attempt-to-escape frequency is extracted to be 10{sup 7} s{sup −1}. These values are in remarkable agreement with measurements in a-IGZO TFTs under negative gate bias illumination stress (NBIS) reported recently (Flewitt and Powell, J. Appl. Phys. 115, 134501 (2014)). This suggests that the same physical process is responsible for both PBS and NBIS, and supports the oxygen vacancy defect migration model that the authors have previously proposed.

Effect of chronic restraint stress on inhibitory gating in the auditory cortex of rats.

Science.gov (United States)

Ma, Lanlan; Li, Wai; Li, Sibin; Wang, Xuejiao; Qin, Ling

2017-05-01

A fundamental adaptive mechanism of auditory function is inhibitory gating (IG), which refers to the attenuation of neural responses to repeated sound stimuli. IG is drastically impaired in individuals with emotional and cognitive impairments (i.e. posttraumatic stress disorder). The objective of this study was to test whether chronic stress impairs the IG of the auditory cortex (AC). We used the standard two-tone stimulus paradigm and examined the parametric qualities of IG in the AC of rats by recording the electrophysiological signals of a single-unit and local field potential (LFP) simultaneously. The main results of this study were that most of the AC neurons showed a weaker response to the second tone than to the first tone, reflecting an IG of the repeated input. A fast negative wave of LFP showed consistent IG across the sampled AC sites, whereas a slow positive wave of LFP had less IG effect. IG was diminished following chronic restraint stress at both, the single-unit and LFP level, due to the increase in response to the second tone. This study provided new evidence that chronic stress disrupts the physiological function of the AC. Lay Summary The effects of chronic stress on IG were investigated by recording both, single-unit spike and LFP activities, in the AC of rats. In normal rats, most of the single-unit and N25 LFP activities in the AC showed an IG effect. IG was diminished following chronic restraint stress at both, the single-unit and LFP level.

Bias-induced migration of ionized donors in amorphous oxide semiconductor thin-film transistors with full bottom-gate and partial top-gate structures

Directory of Open Access Journals (Sweden)

Mallory Mativenga

2012-09-01

Full Text Available Bias-induced charge migration in amorphous oxide semiconductor thin-film transistors (TFTs confirmed by overshoots of mobility after bias stressing dual gated TFTs is presented. The overshoots in mobility are reversible and only occur in TFTs with a full bottom-gate (covers the whole channel and partial top-gate (covers only a portion of the channel, indicating a bias-induced uneven distribution of ionized donors: Ionized donors migrate towards the region of the channel that is located underneath the partial top-gate and the decrease in the density of ionized donors in the uncovered portion results in the reversible increase in mobility.

Retracted: Addition of a single methyl group to a small molecule sodium channel inhibitor introduces a new mode of gating modulation, by L Wang, SG Zellmer, DM Printzenhoff and NA Castle. British Journal of Pharmacology, volume 172(20): 4905-4918, published in October 2015; DOI 10.1111/bph.13259.

Science.gov (United States)

2018-07-01

The above article, published by the British Journal of Pharmacology in October 2015 (https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/bph.13259), has been retracted by agreement between the authors, the journal Editor in Chief and John Wiley & Sons Limited. The retraction has been agreed owing to the discovery of errors in the chemical structure of the synthetic compounds generated. The corrected structure is now available in the article PF-06526290 can both enhance and inhibit conduction through voltage gated sodium channels by L Wang, SG Zellmer, DM Printzenhoff and NA Castle, 2018, https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/bph.14338. Reference Wang L, Zellmer SG, Printzenhoff DM, Castle NA (2015). Addition of a single methyl group to a small molecule sodium channel inhibitor introduces a new mode of gating modulation. Br J Pharmacol 172: 4905-4918. https://doi.org/10.1111/bph.13259. © 2018 The British Pharmacological Society.

Pharmacological reduction of ER stress protects against TDP-43 neuronal toxicity in vivo.

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Vaccaro, Alexandra; Patten, Shunmoogum A; Aggad, Dina; Julien, Carl; Maios, Claudia; Kabashi, Edor; Drapeau, Pierre; Parker, J Alex

2013-07-01

C. elegans and D. rerio expressing mutant TAR DNA Binding Protein 43 (TDP-43) are powerful in vivo animal models for the genetics and pharmacology of amyotrophic lateral sclerosis (ALS). Using these small-animal models of ALS, we previously identified methylene blue (MB) as a potent suppressor of TDP-43 toxicity. Consequently here we investigated how MB might exert its neuroprotective properties and found that it acts through reduction of the endoplasmic reticulum (ER) stress response. We tested other compounds known to be active in the ER unfolded protein response in worms and zebrafish expressing mutant human TDP-43 (mTDP-43). We identified three compounds: salubrinal, guanabenz and a new structurally related compound phenazine, which also reduced paralysis, neurodegeneration and oxidative stress in our mTDP-43 models. Using C. elegans genetics, we showed that all four compounds act as potent suppressors of mTDP-43 toxicity through reduction of the ER stress response. Interestingly, these compounds operate through different branches of the ER unfolded protein pathway to achieve a common neuroprotective action. Our results indicate that protein-folding homeostasis in the ER is an important target for therapeutic development in ALS and other TDP-43-related neurodegenerative diseases. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Agreement of left ventricular ejection fraction and volumes between adenosine stress TL-201 gated SPECT and echocardiography

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Pai, M. S. [College of Medicine, Univ. of Ewha, Seoul (Korea, Republic of); Moon, D. H.; Kim, H. M.; Yang, Y. J.; Kang, D. H. [Asan Medical Center, Seoul (Korea, Republic of)

2003-07-01

Electrocardiogram-gated TI-201 SPECT measurements of left ventricular ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) have shown high correlation with conventional methods. However, how much these parameters measured by TI-201 gated SPECT differ from those by echocardiography has not been assessed. Adenosine stress (Ad-G) and redistribution TI-201 gated SPECT (Re-G) and resting echocardiography were conducted in 337 patients (184 male, 153 female). EDV, ESV and LVEF measured by QGS software were compared with the results by echocardiography. Patients with arrhythmia (atrial fibrillation or frequent premature contractions) or evidence of fixed or reversible perfusion defects on TI-201 SPECT were excluded. EF, EDV and ESV measured by Ad-G (63.3{+-}9.8,73.8{+-}30.2,29.1{+-}20.1) and Re-G (65.2{+-}11.6,69.1{+-}30.1,26.5{+-}20.3) correlated well with those by Echo (61.4{+-}7.9,78.3{+-}2.7, 30.7{+-} 17.5 ; r of Ad-G=0.547, 0.850, 0.827, p<0.001 ; r of Re-G=0.585, 0.838, 0.819, p<0.001). However the difference (mean, SD, SEE of Echo - gated SPECT) was statistically significant (EF: Ad-G=1.71, 8.92, 0.48, Re-G=3.59, 10.39, 0.56, p<0.001 ; EDV: Ad-G=4.75, 16.21, 0.88, Re-G=9.53, 16.77, 0.91, p<0.001 ; ESV: Ad-G=1.75, 11.35, 0.61, p<0.05, Re-G=4.29, 11.7, 0.63, p<0.001). Bland-Altman plots showed that the difference of EDV and ESV did not vary in any systematic way over the range of measurement, whereas the difference of EF increased with increasing average EF by Echo and gated-SPECT. The difference of EF, EDV, and ESV between Ad-G and Echo was significantly smaller than those between Re-G and Echo (p<0.001). Gated TI-201 SPECT underestimates EDV and ESV over a wide range of volume. As a result, EF by gated TI-201 SPECT is overestimated especially in patients with small LV volume. Ad-G is preferable to Re-G in assessing left ventricular ejection fraction and volume in place of Echo because of smaller bias.

Prediction of improvement of myocardial wall motion after coronary artery bypass surgery using rest Tl-201/dipyridamole stress gated Tc-99m-MIBI/24 hour delay Tl-201 SPECT

International Nuclear Information System (INIS)

Lee, Dong Soo; Lee, Won Woo; Yeo, Jeong Yeo; Kim, Seok Ki; Kim, Ki Bong; Chung, June Key; Lee, Myung Chul

1998-01-01

Using rest Tl-201/ dipyridamole stress gated Tc-99m-MIBI/24 hour delay Tl-201 SPECT, we investigated the predictive values of the markers of the stress-rest reversibility (Rev), Tl-201 rest perfusion (Rest), Tl-201 24 hour redistribution (Del) and Tc-99m-MIBI gated systolic thickening (Thk) for wall motion improvement after coronary artery bypass surgery. In 39 patients (M:F=34:5, age 58±8), preoperative and postoperative (3 months) SPECT were compared. 24 hour delayed SPECT was done in 16 patients having perfusion defects at rest. Perfusion or wall motion was scored from 0 to 3 (0: normal to 3: defect or dyskinesia). Wall motion was abnormal in 142 segments among 585 segments of 99 artery territories which were surgically revascularized. After bypass surgery, ejection fraction increased from 37.8±9.0% to 45.5±12.3% in 22 patients who had decreased ejectin fraction preoperatively. Wall motion improved in 103 (72.5%) segments among 142 dysfunctional segments. Positive predictive values (PPV) of Rev, Rest, Del, and Thk were 83%, 76%, 43%, and 69% respectively. Negative predictive values (NPV) of Rev, Rest, Del, and Thk were 48%, 44%, 58%, and 21%, respectively. Rest/gated stress/delay SPECT had PPV of 74% and NPV of 46%. Through univariate logistic regression analysis revealed Rev( p=0.0008) and Rest (p=0.024) as significant predictors, stepwise multivariate test found Rev as the only good predictor (p=0.0008). Among independent predictors obtained by rest Tl-201/stress gated Tc-99m-MIBI/delayed Tl-201 myocardial SPECT for wall motion improvement after bypass surgery, stress-rest reversibility was the single most useful predictor

Toxins That Affect Voltage-Gated Sodium Channels.

Science.gov (United States)

Ji, Yonghua

2017-10-26

Voltage-gated sodium channels (VGSCs) are critical in generation and conduction of electrical signals in multiple excitable tissues. Natural toxins, produced by animal, plant, and microorganisms, target VGSCs through diverse strategies developed over millions of years of evolutions. Studying of the diverse interaction between VGSC and VGSC-targeting toxins has been contributing to the increasing understanding of molecular structure and function, pharmacology, and drug development potential of VGSCs. This chapter aims to summarize some of the current views on the VGSC-toxin interaction based on the established receptor sites of VGSC for natural toxins.

Effect of top gate bias on photocurrent and negative bias illumination stress instability in dual gate amorphous indium-gallium-zinc oxide thin-film transistor

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Lee, Eunji; Chowdhury, Md Delwar Hossain; Park, Min Sang; Jang, Jin, E-mail: jjang@khu.ac.kr [Advanced Display Research Center and Department of Information Display, Kyung Hee University, Seoul 130-701 (Korea, Republic of)

2015-12-07

We have studied the effect of top gate bias (V{sub TG}) on the generation of photocurrent and the decay of photocurrent for back channel etched inverted staggered dual gate structure amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film-transistors. Upon 5 min of exposure of 365 nm wavelength and 0.7 mW/cm{sup 2} intensity light with negative bottom gate bias, the maximum photocurrent increases from 3.29 to 322 pA with increasing the V{sub TG} from −15 to +15 V. By changing V{sub TG} from negative to positive, the Fermi level (E{sub F}) shifts toward conduction band edge (E{sub C}), which substantially controls the conversion of neutral vacancy to charged one (V{sub O} → V{sub O}{sup +}/V{sub O}{sup 2+} + e{sup −}/2e{sup −}), peroxide (O{sub 2}{sup 2−}) formation or conversion of ionized interstitial (O{sub i}{sup 2−}) to neutral interstitial (O{sub i}), thus electron concentration at conduction band. With increasing the exposure time, more carriers are generated, and thus, maximum photocurrent increases until being saturated. After negative bias illumination stress, the transfer curve shows −2.7 V shift at V{sub TG} = −15 V, which gradually decreases to −0.42 V shift at V{sub TG} = +15 V. It clearly reveals that the position of electron quasi-Fermi level controls the formation of donor defects (V{sub O}{sup +}/V{sub O}{sup 2+}/O{sub 2}{sup 2−}/O{sub i}) and/or hole trapping in the a-IGZO /interfaces.

Electrophysiological and Pharmacological Analyses of Nav1.9 Voltage-Gated Sodium Channel by Establishing a Heterologous Expression System

Directory of Open Access Journals (Sweden)

Xi Zhou

2017-11-01

Full Text Available Nav1. 9 voltage-gated sodium channel is preferentially expressed in peripheral nociceptive neurons. Recent progresses have proved its role in pain sensation, but our understanding of Nav1.9, in general, has lagged behind because of limitations in heterologous expression in mammal cells. In this work, functional expression of human Nav1.9 (hNav1.9 was achieved by fusing GFP to the C-terminal of hNav1.9 in ND7/23 cells, which has been proved to be a reliable method to the electrophysiological and pharmacological studies of hNav1.9. By using the hNav1.9 expression system, we investigated the electrophysiological properties of four mutations of hNav1.9 (K419N, A582T, A842P, and F1689L, whose electrophysiological functions have not been determined yet. The four mutations significantly caused positive shift of the steady-state fast inactivation and therefore increased hNav1.9 activity, consistent with the phenotype of painful peripheral neuropathy. Meanwhile, the effects of inflammatory mediators on hNav1.9 were also investigated. Impressively, histamine was found for the first time to enhance hNav1.9 activity, indicating its vital role in hNav1.9 modulating inflammatory pain. Taken together, our research provided a useful platform for hNav1.9 studies and new insight into mechanism of hNav1.9 linking to pain.

Pharmacological inhibition of arachidonate 15-lipoxygenase (ALOX15) protects human spermatozoa against oxidative stress.

Science.gov (United States)

Walters, Jessica L H; De Iuliis, Geoffry N; Dun, Matthew D; Aitken, Robert John; McLaughlin, Eileen A; Nixon, Brett; Bromfield, Elizabeth G

2018-03-13

One of the leading causes of male infertility is defective sperm function, a pathology that commonly arises from oxidative stress in the germline. Lipid peroxidation events in the sperm plasma membrane result in the generation of cytotoxic aldehydes such as 4-hydroxynonenal (4HNE), which accentuate the production of reactive oxygen species (ROS) and cause cellular damage. One of the key enzymes involved in the metabolism of polyunsaturated fatty acids to 4HNE in somatic cells is arachidonate 15-lipoxygenase (ALOX15). Although ALOX15 has yet to be characterized in human spermatozoa, our previous studies have revealed a strong link between ALOX15 activity and the levels of oxidative stress and 4HNE in mouse germ cell models. In view of these data, we sought to assess the function of ALOX15 in mature human spermatozoa and determine whether the pharmacological inhibition of this enzyme could influence the level of oxidative stress experienced by these cells. By driving oxidative stress in vitro with exogenous H2O2, our data reveal that 6,11-dihydro[1]benzothiopyrano[4,3-b]indole (PD146176; a selective ALOX15 inhibitor), was able to significantly reduce several deleterious, oxidative insults in spermatozoa. Indeed, PD146176 attenuated the production of ROS, as well as membrane lipid peroxidation and 4HNE production in human spermatozoa. Accordingly, ALOX15 inhibition also protected the functional competence of these cells to acrosome react and bind homologous human zonae pellucidae. Together, these results implicate ALOX15 in the propagation of an oxidative stress cascade within human spermatozoa and offer insight into potential therapeutic avenues to address male fertility that arises from oxidative stress.

Reference Range of Functional Data of Gated Myocardial Perfusion SPECT by Quantitative Gated SPECT of Cedars-Sinai and 4D-MSPECT of Michigan University

Energy Technology Data Exchange (ETDEWEB)

Kang, Do Young; Kim, Moo Hyun; Kim, Young Dae [College of Medicine, Univ. of Donga, Pusan (Korea, Republic of)

2003-07-01

Various programs have been developed for gating of myocardial perfusion SPECT. Among the those program, the most popular program is the Quantitative Gated SPECT (QGS)? developed by Cedars-Sinai hospital and most recently released program is 4D-MSPECT? developed by university of Michigan. It is important to know the reference range of the functional data of gated myocardial perfusion SPECT because it is necessary to determine abnormality of individual patient and echocardiographic data is different from those of gated SPECT. Tc-99m MIBI gated myocardial perfusion SPECT image was reconstructed by dual head gamma camera (Siemens, BCAM, esoft) as routine procedure and analyzed using QGS? and 4D-MSPECT? program. All patients (M: F=9: 18, Age 69{+-}9 yrs) showed normal myocardial perfusion. The patients with following characteristics were excluded: previous angina or MI history, ECG change with Q wave or ST-T change, diabetes melitius, hypercholesterolemia, typical chest pain, hypertension and cardiomyopathy. Pre-test likelihood of all patients was low. (1) In stress gated SPECT by QGS?, EDV was 73{+-}25 ml, ESV 25{+-}14 ml, EF 67{+-}11 % and area of first frame of gating 106.4{+-}21cm{sup 2}. In rest gated SPECT, EDV was 76{+-}26 ml, ESV 27{+-}15 ml, EF 66{+-}12 and area of first frame of gating 108{+-}20cm{sup 2}. (2) In stress gated SPECT by 4D-MSPECT?, EDV was 76{+-}28 ml, ESV 23{+-}16 ml, EF 72{+-}11 %, mass 115{+-}24 g and ungated volume 42{+-}15 ml. In rest gated SPECT, EDV was 75{+-}27 ml, ESV 23{+-}12 ml, EF 71{+-}9%, mass 113{+-}25g and ungate dvolume 42{+-}15 ml, (3) s-EDV, s-EF, r-ESV and r-EF were significantly different between QGS? and 4D-MSPECT? (each p=0.016, p<0.001. p=0.003 and p=0.001). We determined the normal reference range of functional parameters by QGS? and 4D-MSPECT? program to diagnose individually the abnormality of patients. And the reference ranges have to adopted to be patients by each specific gating program.

The novel isoxazoline ectoparasiticide lotilaner (Credelio™): a non-competitive antagonist specific to invertebrates γ-aminobutyric acid-gated chloride channels (GABACls)

OpenAIRE

Rufener, Lucien; Danelli, Vanessa; Bertrand, Daniel; Sager, Heinz

2017-01-01

Background The isoxazolines are a novel class of parasiticides that are potent inhibitors of γ-aminobutyric acid (GABA)-gated chloride channels (GABACls) and, to a lesser extent, of inhibitory glutamate-gated chloride channels (GluCls). Lotilaner (Credelio™), a novel representative of this chemical class, is currently evaluated for its excellent ectoparasiticide properties. Methods In this study, we investigated the molecular mode of action and pharmacology of lotilaner. We report the success...

Rapid gated Thallium-201 perfusion SPECT - clinically feasible?

International Nuclear Information System (INIS)

Wadhwa, S.S.; Mansberg, R.; Fernandes, V.B.; Wilkinson, D.; Abatti, D.

1998-01-01

Full text: Standard dose energy window optimised Thallium-201 (Tl-201) SPECT has about half the counts of a standard dose from Technetium-99m Sestamibi (Tc99m-Mibi) gated perfusion SPECT. This study investigates the clinical feasibility of rapid energy window optimised Tl-201 gated perfusion SPECT (gated-TI) and compares quantitative left ventricular ejection fraction (LVEF) and visually assessed image quality for wall motion and thickening to analogous values obtained from Tc99m-Mibi gated perfusion SPECT (gated - mibi). Methods: We studied 60 patients with a rest gated Tl-201 SPECT (100 MBq, 77KeV peak, 34% window, 20 sec/projection) followed by a post stress gated Sestamibi SPECT (1GBq, 140KeV, 20% window, 20 sec/projection) separate dual isotope protocol. LVEF quantitation was performed using commercially available software (SPECTEF, General Electric). Visual grading of image quality for wall thickening and motion was performed using a three-point scale (excellent, good and poor). Results: LVEF for gated Tl-201 SPECT was 59.6 ± 12.0% (Mean ± SD). LVEF for gated Sestamibi SPECT was 60.4 ±11.4% (Mean ± SD). These were not significantly different (P=0.27, T-Test). There was good correlation (r=0.9) between gated-TI and gated-mibi LVEF values. The quality of gated-Tl images was ranked as excellent, good and poor in 12, 50 and 38% of the patients respectively. Image quality was better in gated-mibi SPECT, with ratings of 12, 62 and 26% respectively. Conclusion: Rapid gated Thallium-201 acquisition with energy window optimisation can be effectively performed on majority of patients and offers the opportunity to assess not only myocardial perfusion and function, as with Technetium based agents, but also viability using a single day one isotope protocol

Gate voltage and drain current stress instabilities in amorphous In–Ga–Zn–O thin-film transistors with an asymmetric graphene electrode

Directory of Open Access Journals (Sweden)

Joonwoo Kim

2015-09-01

Full Text Available The gate voltage and drain current stress instabilities in amorphous In–Ga–Zn–O thin-film transistors (a-IGZO TFTs having an asymmetric graphene electrode structure are studied. A large positive shift in the threshold voltage, which is well fitted to a stretched-exponential equation, and an increase in the subthreshold slope are observed when drain current stress is applied. This is due to an increase in temperature caused by power dissipation in the graphene/a-IGZO contact region, in addition to the channel region, which is different from the behavior in a-IGZO TFTs with a conventional transparent electrode.

Characterizing ligand-gated ion channel receptors with genetically encoded Ca2++ sensors.

Directory of Open Access Journals (Sweden)

John G Yamauchi

2011-01-01

Full Text Available We present a cell based system and experimental approach to characterize agonist and antagonist selectivity for ligand-gated ion channels (LGIC by developing sensor cells stably expressing a Ca(2+ permeable LGIC and a genetically encoded Förster (or fluorescence resonance energy transfer (FRET-based calcium sensor. In particular, we describe separate lines with human α7 and human α4β2 nicotinic acetylcholine receptors, mouse 5-HT(3A serotonin receptors and a chimera of human α7/mouse 5-HT(3A receptors. Complete concentration-response curves for agonists and Schild plots of antagonists were generated from these sensors and the results validate known pharmacology of the receptors tested. Concentration-response relations can be generated from either the initial rate or maximal amplitudes of FRET-signal. Although assaying at a medium throughput level, this pharmacological fluorescence detection technique employs a clonal line for stability and has versatility for screening laboratory generated congeners as agonists or antagonists on multiple subtypes of ligand-gated ion channels. The clonal sensor lines are also compatible with in vivo usage to measure indirectly receptor activation by endogenous neurotransmitters.

A comparative study on top-gated and bottom-gated multilayer MoS2 transistors with gate stacked dielectric of Al2O3/HfO2.

Science.gov (United States)

Zou, Xiao; Xu, Jingping; Huang, Hao; Zhu, Ziqang; Wang, Hongjiu; Li, Borui; Liao, Lei; Fang, Guojia

2018-06-15

Top-gated and bottom-gated transistors with multilayer MoS 2 channel fully encapsulated by stacked Al 2 O 3 /HfO 2 (9 nm/6 nm) were fabricated and comparatively studied. Excellent electrical properties are demonstrated for the TG transistors with high on-off current ratio of 10 8 , high field-effect mobility of 10 2 cm 2 V -1 s -1 , and low subthreshold swing of 93 mV dec -1 . Also, enhanced reliability has been achieved for the TG transistors with threshold voltage shift of 10 -3 -10 -2 V MV -1 cm -1 after 6 MV cm -1 gate-biased stressing. All improvement for the TG device can be ascribed to the formed device structure and dielectric environment. Degradation of the performance for the BG transistors should be attributed to reduced gate capacitance density and deteriorated interface properties related to vdW gap with a thickness about 0.4 nm. So, the TG transistor with MoS 2 channel fully encapsulated by stacked Al 2 O 3 /HfO 2 is a promising way to fabricate high-performance ML MoS 2 field-effect transistors for practical electron device applications.

Abnormal response to mental stress in patients with Takotsubo cardiomyopathy detected by gated single photon emission computed tomography

International Nuclear Information System (INIS)

Sciagra, Roberto; Genovese, Sabrina; Pupi, Alberto; Parodi, Guido; Bellandi, Benedetta; Antoniucci, David; Del Pace, Stefano; Zampini, Linda; Gensini, Gian Franco

2010-01-01

Persistent abnormalities are usually not detected in patients with Takotsubo cardiomyopathy (TTC). Since sympathetically mediated myocardial damage has been proposed as a causative mechanism of TTC, we explored whether mental stress could evoke abnormalities in these patients. One month after an acute event, 22 patients fulfilling all TTC diagnostic criteria and 11 controls underwent resting and mental stress gated single photon emission computed tomography (SPECT). Perfusion, wall motion, transient ischaemic dilation (TID) and left ventricular (LV) ejection fraction (EF) were evaluated. None of the controls showed stress-induced abnormalities. Mental stress evoked regional changes (perfusion defects and/or wall motion abnormality) in 16 TTC subjects and global abnormalities (LVEF fall >5% and/or TID >1.10) in 13; 3 had a completely negative response. TID, delta LVEF and delta wall motion score were significantly different in TTC vs control patients: 1.08 ± 0.20 vs 0.95 ± 0.11 (p < 0.05), -1.7 ± 6% vs 4 ± 5% (p < 0.02) and 2.5 (0, 4.25) vs 0 (0, 0) (p < 0.002), respectively. Mental stress may evoke regional and/or global abnormalities in most TTC patients. The abnormal response to mental stress supports the role of sympathetic stimulation in TTC. Mental stress could thus be helpful for TTC evaluation. (orig.)

Unusual Voltage-Gated Sodium Currents as Targets for Pain.

Science.gov (United States)

Barbosa, C; Cummins, T R

2016-01-01

Pain is a serious health problem that impacts the lives of many individuals. Hyperexcitability of peripheral sensory neurons contributes to both acute and chronic pain syndromes. Because voltage-gated sodium currents are crucial to the transmission of electrical signals in peripheral sensory neurons, the channels that underlie these currents are attractive targets for pain therapeutics. Sodium currents and channels in peripheral sensory neurons are complex. Multiple-channel isoforms contribute to the macroscopic currents in nociceptive sensory neurons. These different isoforms exhibit substantial variations in their kinetics and pharmacology. Furthermore, sodium current complexity is enhanced by an array of interacting proteins that can substantially modify the properties of voltage-gated sodium channels. Resurgent sodium currents, atypical currents that can enhance recovery from inactivation and neuronal firing, are increasingly being recognized as playing potentially important roles in sensory neuron hyperexcitability and pain sensations. Here we discuss unusual sodium channels and currents that have been identified in nociceptive sensory neurons, describe what is known about the molecular determinants of the complex sodium currents in these neurons. Finally, we provide an overview of therapeutic strategies to target voltage-gated sodium currents in nociceptive neurons. Copyright © 2016 Elsevier Inc. All rights reserved.

Non-pharmacological interventions to manage fatigue and psychological stress in children and adolescents with cancer: an integrative review.

Science.gov (United States)

Lopes-Júnior, L C; Bomfim, E O; Nascimento, L C; Nunes, M D R; Pereira-da-Silva, G; Lima, R A G

2016-11-01

Cancer-related fatigue (CRF) is the most stressful and prevalent symptom in paediatric oncology patients. This integrative review aimed to identify, analyse and synthesise the evidence of non-pharmacological intervention studies to manage fatigue and psychological stress in a paediatric population with cancer. Eight electronic databases were used for the search: PubMed, Web of Science, CINAHL, LILACS, EMBASE, SCOPUS, PsycINFO and the Cochrane Library. Initially, 273 articles were found; after the exclusion of repeated articles, reading of the titles, abstracts and the full articles, a final sample of nine articles was obtained. The articles were grouped into five categories: physical exercise, healing touch, music therapy, therapeutic massage, nursing interventions and health education. Among the nine studies, six showed statistical significance regarding the fatigue and/or stress levels, showing that the use of the interventions led to symptoms decrease. The most frequently tested intervention was programmed physical exercises. It is suggested that these interventions are complementary to conventional treatment and that their use can indicate an improvement in CRF and psychological stress. © 2015 John Wiley & Sons Ltd.

Intron retention in mRNA encoding ancillary subunit of insect voltage-gated sodium channel modulates channel expression, gating regulation and drug sensitivity.

Directory of Open Access Journals (Sweden)

Céline M Bourdin

Full Text Available Insect voltage-gated sodium (Nav channels are formed by a well-known pore-forming α-subunit encoded by para-like gene and ancillary subunits related to TipE from the mutation "temperature-induced-paralysis locus E." The role of these ancillary subunits in the modulation of biophysical and pharmacological properties of Na(+ currents are not enough documented. The unique neuronal ancillary subunit TipE-homologous protein 1 of Drosophila melanogaster (DmTEH1 strongly enhances the expression of insect Nav channels when heterologously expressed in Xenopus oocytes. Here we report the cloning and functional expression of two neuronal DmTEH1-homologs of the cockroach, Periplaneta americana, PaTEH1A and PaTEH1B, encoded by a single bicistronic gene. In PaTEH1B, the second exon encoding the last 11-amino-acid residues of PaTEH1A is shifted to 3'UTR by the retention of a 96-bp intron-containing coding-message, thus generating a new C-terminal end. We investigated the gating and pharmacological properties of the Drosophila Nav channel variant (DmNav1-1 co-expressed with DmTEH1, PaTEH1A, PaTEH1B or a truncated mutant PaTEH1Δ(270-280 in Xenopus oocytes. PaTEH1B caused a 2.2-fold current density decrease, concomitant with an equivalent α-subunit incorporation decrease in the plasma membrane, compared to PaTEH1A and PaTEH1Δ(270-280. PaTEH1B positively shifted the voltage-dependences of activation and slow inactivation of DmNav1-1 channels to more positive potentials compared to PaTEH1A, suggesting that the C-terminal end of both proteins may influence the function of the voltage-sensor and the pore of Nav channel. Interestingly, our findings showed that the sensitivity of DmNav1-1 channels to lidocaine and to the pyrazoline-type insecticide metabolite DCJW depends on associated TEH1-like subunits. In conclusion, our work demonstrates for the first time that density, gating and pharmacological properties of Nav channels expressed in Xenopus oocytes can be

Prognostic significance of stress myocardial ECG-gated perfusion imaging in asymptomatic patients with diabetic chronic kidney disease on initiation of haemodialysis

Energy Technology Data Exchange (ETDEWEB)

Momose, Mitsuru; Kondo, Chisato; Kobayashi, Hideki; Kusakabe, Kiyoko [Tokyo Women' s Medical University, School of Medicine, Department of Radiology, Shinjuku-ku, Tokyo (Japan); Babazono, Tetsuya [Tokyo Women' s Medical University, School of Medicine, Diabetes Centre, Shinjuku-ku, Tokyo (Japan); Nakajima, Takatomo [Tokyo Women' s Medical University, School of Medicine, Department of Cardiology, Shinjuku-ku, Tokyo (Japan)

2009-08-15

Diabetic patients with chronic kidney disease (CKD) frequently develop cardiac events within several years of the initiation of haemodialysis. The present study assesses the prognostic significance of stress myocardial ECG-gated perfusion imaging (MPI) in patients with diabetic CKD requiring haemodialysis. Fifty-five asymptomatic patients with diabetic stage V CKD and no history of heart disease scheduled to start haemodialysis were enrolled in this study (56{+-}11 years old; 49 with type 2 diabetes mellitus). All patients underwent {sup 201}Tl stress ECG-gated MPI 1 month before or after the initiation of haemodialysis to assess myocardial involvement. We evaluated SPECT images using 17-segment defect scores graded on a 5-point scale, summed stress score (SSS) and summed difference scores (SDS). The patients were followed up for at least 2 years (42{+-}15 months) to determine coronary intervention (CI) and heart failure (HF) as soft events and acute myocardial infarction (AMI) and all causes of deaths as hard events. The frequencies of myocardial ischaemia, resting perfusion defects, low ejection fraction and left ventricular (LV) dilatation were 24,20,29 and 49%, respectively. Ten events (18%) developed during the follow-up period including four CI, one HF, one AMI and four sudden deaths. Multivariate Cox analysis selected SDS (p=0.0011) and haemoglobin A{sub 1c} (HbA{sub 1c}) (p=0.0076) as independent prognostic indicators for all events. Myocardial ischaemia, in addition to glycaemic control, is a strong prognostic marker for asymptomatic patients with diabetic CKD who are scheduled to start haemodialysis. Stress MPI is highly recommended for the management and therapeutic stratification of such patients. (orig.)

Comparison of left ventricular ejection fraction by 201Tl gated SPECT and gated blood pool scan

International Nuclear Information System (INIS)

Lau, W.F.E.; Kelly, M.J.; O'Donnell, M.; Kalff, V.; Van Every, B.

2000-01-01

Full text: The aim of this study was to evaluate left ventricular ejection fraction (LVEF) determination by the Germano 201 Tl gated-SPECT myocardial perfusion (TLGSMP) method using gated blood pool scintigraphy (GBPS) as a reference. 21 patients underwent both TLGSMP and GBPS within eight days of each other from June 1997 to Jan 2000. Acquisition of TLGSMP was performed on a GE Optima NX dual head camera using Tl-201 dose of 1.5MBq/Kg and imaging time of 45 cardiac cycles/step with 16 steps/90 Deg of rotation per detector. All LVEF results were determined using a GE Genie workstation. GBPS results were compared with TLGSMP results for LVEF obtained from the reinjection images using automated Germano processing, and from the stress images using automatic and manual processing. Duplicate automatic analysis by a second observer produced identical mean TLGSMP LVEF results (r = 0.99). Stress TLGSMP LVEF by the automatic and manual processing correlate well (r = 0.99) but the manual LVEF is significantly lower. In conclusion LVEF determination using TLGSMP is highly reproducible and is also accurate when applied to reinjection data. Both manual processing and the use of stress data lead to underestimation of LVEF. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

Normal LVEF measurements are significantly higher in females asassessed by post-stress resting Tc-99m sestamibi gated myocardial perfusion SPECT

International Nuclear Information System (INIS)

Kim, Jong Ho; Shin, Eak Kyun

1999-01-01

Volume-LVEF relationship is one of the most important factors of automatic EF quantification algorithm from gated myocardial perfusion SPECT(gMPS) (Germano et al. JNM, 1995). Gender difference whereby normal LVEF measurements are higher in females assessed by gMPS (Yao et al. JNM 1997). To validate true physiologic value of LVEF vs sampling or measured error, various parameters were evaluated statistically in both gender and age matched 200 subjects (mean age= 58.41±15.01) with normal LVEF more than 50%, and a low likelihood of coronary artery disease. Correlation between LVEDVi(ml/m2) and LVEF was highly significant (r=-0.62, p<0.0001) with similar correlations noted in both male (r=-0.45, p<0.0001) and female (r=-0.67, p<0.0001) subgroups. By multivariate analysis, LV volume and stroke volume was the most significant factor influencing LVEF in male and female, respectively. In conclusion, there is a significant negative correlation between LV volume and LVEF as measured by Tc-99m gated SPECT. Higher normal LVEF value should be applied to females as assessed by post-stress resting Tc-99m Sestamibi gated myocardial perfusion SPECT

New Role of P/Q-type Voltage-gated Calcium Channels

DEFF Research Database (Denmark)

Hansen, Pernille B L

2015-01-01

Voltage-gated calcium channels are important for the depolarization-evoked contraction of vascular smooth muscle cells (SMCs), with L-type channels being the classical channel involved in this mechanism. However, it has been demonstrated that the CaV2.1 subunit, which encodes a neuronal isoform...... of the voltage-gated calcium channels (P/Q-type), is also expressed and contributes functionally to contraction of renal blood vessels in both mice and humans. Furthermore, preglomerular vascular SMCs and aortic SMCs coexpress L-, P-, and Q-type calcium channels within the same cell. Calcium channel blockers...... are widely used as pharmacological treatments. However, calcium channel antagonists vary in their selectivity for the various calcium channel subtypes, and the functional contribution from P/Q-type channels as compared with L-type should be considered. Confirming the presence of P/Q-type voltage...

High-Performance Ink-Synthesized Cu-Gate Thin-Film Transistor with Diffusion Barrier Formation

Science.gov (United States)

Woo, Whang Je; Nam, Taewook; Oh, Il-Kwon; Maeng, Wanjoo; Kim, Hyungjun

2018-05-01

The improved electrical properties of Cu-gate thin-film transistors (TFTs) using an ink-synthesizing process were studied; this technology enables a low-cost and large area process for the display industry. We investigated the film properties and the effects of the ink-synthesized Cu layer in detail with respect to device characteristics. The mobility and reliability of the devices were significantly improved by applying a diffusion barrier at the interface between the Cu gate and the gate insulator. By using a TaN diffusion barrier layer, considerably improved and stabilized ink-Cu gated TFTs could be realized, comparable to sputtered-Cu gated TFTs under positive bias temperature stress measurements.

High-Performance Ink-Synthesized Cu-Gate Thin-Film Transistor with Diffusion Barrier Formation

Science.gov (United States)

Woo, Whang Je; Nam, Taewook; Oh, Il-Kwon; Maeng, Wanjoo; Kim, Hyungjun

2018-02-01

The improved electrical properties of Cu-gate thin-film transistors (TFTs) using an ink-synthesizing process were studied; this technology enables a low-cost and large area process for the display industry. We investigated the film properties and the effects of the ink-synthesized Cu layer in detail with respect to device characteristics. The mobility and reliability of the devices were significantly improved by applying a diffusion barrier at the interface between the Cu gate and the gate insulator. By using a TaN diffusion barrier layer, considerably improved and stabilized ink-Cu gated TFTs could be realized, comparable to sputtered-Cu gated TFTs under positive bias temperature stress measurements.

Gated single-photon emission tomography imaging protocol to evaluate myocardial stunning after exercise

International Nuclear Information System (INIS)

Hashimoto, Jun; Kubo, Atsushi; Iwasaki, Ryuichiro; Iwanaga, Shiro; Mitamura, Hideo; Ogawa, Satoshi; Kosuda, Shigeru

1999-01-01

This study was designed to apply ECG-gating to stress myocardial perfusion single-photon emission tomography (SPET) for the evaluation of myocardial stunning after exercise. Technetium-99m sestamibi was selected as the perfusion agent and a rest/exercise 1-day protocol was employed. Fourteen patients without coronary stenosis and 33 patients with coronary stenosis were enrolled in the study. We carried out three data acquisitions with ECG-gating: a 15-min data acquisition starting 30 min after the rest injection (AC1), a 5-min acquisition starting 5 min after the stress injection (AC2) and a 15-min acquisition starting 20 min after the stress injection (AC3). Calculation of left ventricular ejection fraction (LVEF) values was performed by means of automatic determination of the endocardial surface for all gating intervals in the cardiac cycle. Measured global EF values in 14 patients without coronary stenosis were 52.3%±7.6% (AC1), 60.6%±8.9% (AC2) and 55.6%±5.6% (AC3), and those in 11 patients with severe ischaemia were 53.6%±8.0% (AC1), 45.6%±12.1% (AC2) and 49.7%±10.7%. The magnitude of the depression of post-stress LVEF relative to the rest LVEF correlated with the severity of ischaemia (r=0.594, P=0.002), and segments manifesting post-stress functional depression were associated with ischaemic segments showing reversible perfusion defects. Stress myocardial perfusion SPET with ECG-gating is a feasible method for the evaluation of myocardial stunning as well as exercise-induced ischaemia. (orig.)

Is 16-frame really superior to 8-frame gated SPECT for the assessment of left ventricular volumes and ejection fraction? Comparison of two simultaneously acquired gated SPECT studies

International Nuclear Information System (INIS)

Montelatici, Giulia; Sciagra, Roberto; Passeri, Alessandro; Dona, Manjola; Pupi, Alberto

2008-01-01

Conflicting data exist about the difference between 8- and 16-frame gated single-photon emission computed tomography (SPECT) left ventricular volumes and ejection fraction (EF); moreover, the influence of framing on detection of stress-induced functional changes is unknown. In 133 patients, two separate gated SPECT studies, one with 8 and one with 16 frames, were simultaneously acquired during a single gantry orbit using dedicated software. In 33 of 133 patients, two additional studies (with 8 and 16 frames, respectively) were acquired using arrhythmia rejection. Left ventricular EF and volumes were calculated using the QGS software. Stress-induced ischemia was identified on summed perfusion images. Arrhythmia-rejection did not influence volumes and EF independently of framing rate. Using data without arrhythmia-rejection, there was a significant difference in volumes and EF between 8 and 16 frames both in resting and post-stress gated SPECT. However, the difference was small: 2.6% for resting and 2.8% for post-stress EF. Both using 8 and 16 frames, there were significantly larger volumes and lower EF in patients with than without stress-induced ischemia. A stress-induced decrease >5 EF units was observed in 26 of 133 patients using 8 and in 23 of 133 using 16 frames, respectively, with finding agreement in 19 patients. Comparing two simultaneously acquired studies, the use of 16 instead of 8 frames has minor and predictable influence on functional data. Furthermore, there are no differences in the detection of stress-induced functional changes. The advantage of 16 over 8 frames in the daily clinical practice appears questionable. (orig.)

Modulation of early stress-induced neurobiological changes: a review of behavioural and pharmacological interventions in animal models.

Science.gov (United States)

Harrison, E L; Baune, B T

2014-05-13

Childhood adversity alters the predisposition to psychiatric disorders later in life. Those with psychiatric conditions and a history of early adversity exhibit a higher incidence of treatment resistance compared with individuals with no such history. Modulation of the influence early stress exerts over neurobiology may help to prevent the development of psychiatric disorders in some cases, while attenuating the extent of treatment resistance in those with established psychiatric disorders. This review aims to critically evaluate the ability of behavioural, environmental and pharmacologic interventions to modulate neurobiological changes induced by early stress in animal models. Databases were systematically searched to locate literature relevant to this review. Early adversity was defined as stress that resulted from manipulation of the mother-infant relationship. Analysis was restricted to animal models to enable characterisation of how a given intervention altered specific neurobiological changes induced by early stress. A wide variety of changes in neurobiology due to early stress are amenable to intervention. Behavioural interventions in childhood, exercise in adolescence and administration of epigenetic-modifying drugs throughout life appear to best modulate cellar and behavioural alterations induced by childhood adversity. Other pharmacotherapies, such as endocannabinoid system modulators, anti-inflammatories and antidepressants can also influence these neurobiological and behavioural changes that result from early stress, although findings are less consistent at present and require further investigation. Further work is required to examine the influence that behavioural interventions, exercise and epigenetic-modifying drugs exert over alterations that occur following childhood stress in human studies, before possible translational into clinical practice is possible.

Reliability study of ultra-thin gate oxides on strained-Si/SiGe MOS structures

International Nuclear Information System (INIS)

Varzgar, John B.; Kanoun, Mehdi; Uppal, Suresh; Chattopadhyay, Sanatan; Tsang, Yuk Lun; Escobedo-Cousins, Enrique; Olsen, Sarah H.; O'Neill, Anthony; Hellstroem, Per-Erik; Edholm, Jonas; Ostling, Mikael; Lyutovich, Klara; Oehme, Michael; Kasper, Erich

2006-01-01

The reliability of gate oxides on bulk Si and strained Si (s-Si) has been evaluated using constant voltage stressing (CVS) to investigate their breakdown characteristics. The s-Si architectures exhibit a shorter life time compared to that of bulk Si, which is attributed to higher bulk oxide charges (Q ox ) and increased surface roughness in the s-Si structures. The gate oxide in the s-Si structure exhibits a hard breakdown (HBD) at 1.9 x 10 4 s, whereas HBD is not observed in bulk Si up to a measurement period of 1.44 x 10 5 s. The shorter lifetime of the s-Si gate oxide is attributed to a larger injected charge (Q inj ) compared to Q inj in bulk Si. Current-voltage (I-V) measurements for bulk Si samples at different stress intervals show an increase in stress induced leakage current (SILC) of two orders in the low voltage regime from zero stress time to up to 5 x 10 4 s. In contrast, superior performance enhancements in terms of drain current, maximum transconductance and effective channel mobility are observed in s-Si MOSFET devices compared to bulk Si. The results from this study indicate that further improvement in gate oxide reliability is needed to exploit the sustained performance enhancement of s-Si devices over bulk Si

Effects of DC gate and drain bias stresses on the degradation of excimer laser crystallized polysilicon thin film transistors

International Nuclear Information System (INIS)

Kouvatsos, D N; Michalas, L; Voutsas, A T; Papaioannou, G J

2005-01-01

The effects of gate and drain bias stresses on thin film transistors fabricated in polysilicon films crystallized using the advanced sequential lateral solidification excimer laser annealing (SLS ELA) process, which yields very elongated polysilicon grains and allows the fabrication of TFTs without grain boundary barriers to current flow, are investigated as a function of the active layer thickness and of the TFT orientation relative to the grains. The application of hot carrier stress, with a condition of V GS = V DS /2, was determined to induce threshold voltage, subthreshold swing and transconductance degradation for TFTs in thicker polysilicon films and the associated stress-induced increase in the active layer trap density was evaluated. However, this device degradation was drastically reduced for TFTs fabricated in ultra-thin films. Furthermore, the application of the same stress condition to TFTs oriented vertically to the elongated grains resulted in similar threshold voltage shift but in substantially decreased subthreshold swing and transconductance degradation. The immunity of ultra-thin active layer devices to degradation under hot carrier stress clearly suggests the implementation of ultra thin SLS ELA polysilicon films for the fabrication of TFTs exhibiting not only high performance but, especially, the high reliability needed for integrated systems on panel

100-nm gate lithography for double-gate transistors

Science.gov (United States)

Krasnoperova, Azalia A.; Zhang, Ying; Babich, Inna V.; Treichler, John; Yoon, Jung H.; Guarini, Kathryn; Solomon, Paul M.

2001-09-01

The double gate field effect transistor (FET) is an exploratory device that promises certain performance advantages compared to traditional CMOS FETs. It can be scaled down further than the traditional devices because of the greater electrostatic control by the gates on the channel (about twice as short a channel length for the same gate oxide thickness), has steeper sub-threshold slope and about double the current for the same width. This paper presents lithographic results for double gate FET's developed at IBM's T. J. Watson Research Center. The device is built on bonded wafers with top and bottom gates self-aligned to each other. The channel is sandwiched between the top and bottom polysilicon gates and the gate length is defined using DUV lithography. An alternating phase shift mask was used to pattern gates with critical dimensions of 75 nm, 100 nm and 125 nm in photoresist. 50 nm gates in photoresist have also been patterned by 20% over-exposure of nominal 100 nm lines. No trim mask was needed because of a specific way the device was laid out. UV110 photoresist from Shipley on AR-3 antireflective layer were used. Process windows, developed and etched patterns are presented.

Sub-50 nm gate length SOI transistor development for high performance microprocessors

International Nuclear Information System (INIS)

Horstmann, M.; Greenlaw, D.; Feudel, Th.; Wei, A.; Frohberg, K.; Burbach, G.; Gerhardt, M.; Lenski, M.; Stephan, R.; Wieczorek, K.; Schaller, M.; Hohage, J.; Ruelke, H.; Klais, J.; Huebler, P.; Luning, S.; Bentum, R. van; Grasshoff, G.; Schwan, C.; Cheek, J.; Buller, J.; Krishnan, S.; Raab, M.; Kepler, N.

2004-01-01

Partial depleted (PD) SOI technologies have reached maturity for production of high speed, low power microprocessors. The paper will highlight several challenges found during the course of development for bringing 40 nm gate length (L GATE ) PD SOI transistors into volume manufacturing for high-speed microprocessors. The key innovations developed for this transistor in order to overcome classical gate oxide and L GATE scaling is an unique differential triple spacer structure, stressed overlayer films inducing strain in the Silicon channel and optimized junctions. This transistor structure yields an outstanding ring oscillator speed with an unloaded inverter delay of 5.5 ps. The found improvements are highly manufacturable and scaleable for future device technologies like FD SOI

Low voltage stress-induced leakage current and traps in ultrathin oxide (1.2 2.5 nm) after constant voltage stresses

Science.gov (United States)

Petit, C.; Zander, D.

2007-10-01

It has been shown that the low voltage gate current in ultrathin oxide metal-oxide-semiconductor devices is very sensitive to electrical stresses. Therefore, it can be used as a reliability monitor when the oxide thickness becomes too small for traditional electrical measurements to be used. In this work, we present a study on n-MOSCAP devices at negative gate bias in the direct tunneling (DT) regime. If the low voltage stress-induced leakage current (LVSILC) depends strongly on the low sense voltages, it also depends strongly on the stress voltage magnitude. We show that two LVSILC peaks appear as a function of the sense voltage in the LVSILC region and that their magnitude, one compared to the other, depends strongly on the stress voltage magnitude. One is larger than the other at low stress voltage and smaller at high stress voltage. From our experimental results, different conduction mechanisms are analyzed. To explain LVSILC variations, we propose a model of the conduction through the ultrathin gate oxide based on two distinctly different trap-assisted tunneling mechanisms: inelastic of gate electron (INE) and trap-assisted electron (ETAT).

Gating-ML: XML-based gating descriptions in flow cytometry.

Science.gov (United States)

Spidlen, Josef; Leif, Robert C; Moore, Wayne; Roederer, Mario; Brinkman, Ryan R

2008-12-01

The lack of software interoperability with respect to gating due to lack of a standardized mechanism for data exchange has traditionally been a bottleneck, preventing reproducibility of flow cytometry (FCM) data analysis and the usage of multiple analytical tools. To facilitate interoperability among FCM data analysis tools, members of the International Society for the Advancement of Cytometry (ISAC) Data Standards Task Force (DSTF) have developed an XML-based mechanism to formally describe gates (Gating-ML). Gating-ML, an open specification for encoding gating, data transformations and compensation, has been adopted by the ISAC DSTF as a Candidate Recommendation. Gating-ML can facilitate exchange of gating descriptions the same way that FCS facilitated for exchange of raw FCM data. Its adoption will open new collaborative opportunities as well as possibilities for advanced analyses and methods development. The ISAC DSTF is satisfied that the standard addresses the requirements for a gating exchange standard.

Pharmacological consequences of oxidative stress in ocular tissues

International Nuclear Information System (INIS)

Ohia, Sunny E.; Opere, Catherine A.; LeDay, Angela M.

2005-01-01

The eye is a unique organ because of its constant exposure to radiation, atmospheric oxygen, environmental chemicals and physical abrasion. That oxidative stress mechanisms in ocular tissues have been hypothesized to play a role in diseases such as glaucoma, cataract, uveitis, retrolental fibroplasias, age-related macular degeneration and various forms of retinopathy provides an opportunity for new approaches to their prevention and treatment, In the anterior uvea, both H 2 O 2 and synthetic peroxides exert pharmacological/toxicological actions tissues of the anterior uvea especially on the sympathetic nerves and smooth muscles of the iris-ciliary bodies of several mammalian species. Effects produced by peroxides require the presence of trace amounts of extracellular calcium and the functional integrity of mitochondrial calcium stores. Arachidonic acid metabolites appear to be involved in both the excitatory action of peroxides on sympathetic neurotransmission and their inhibitory effect on contractility of the iris smooth muscle to muscarinic receptor activation. In addition to the peroxides, isoprostanes (products of free radical catalyzed peroxidation of arachidonic acid independent of the cyclo-oxygenase enzyme) can also alter sympathetic neurotransmission in anterior uveal tissues. In the retina, both H 2 O 2 and synthetic peroxides produced an inhibitory action on potassium depolarization induced release of [ 3 H] D-aspartate, in vitro and on the endogenous glutamate and glycine concentrations in vivo. Effects caused by peroxides in the retina are mediated, at least in part, by second messengers such as nitric oxide, prostaglandins and isoprostanes. The ability of H 2 O 2 to alter the integrity of neurotransmitter pools from sympathetic nerves in the anterior uvea and glutaminergic nerves in the retina could underlie its role in the etiology of glaucoma

Pharmacological consequences of oxidative stress in ocular tissues

Energy Technology Data Exchange (ETDEWEB)

Ohia, Sunny E. [Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 141 Science and Research Building 2, University of Houston, Houston, TX 77204 (United States)]. E-mail: seohia@uh.edu; Opere, Catherine A. [Department of Pharmacy Sciences, School of Pharmacy and Health Professions, Creighton University Medical Center, Omaha, NE 68178 (United States); LeDay, Angela M. [Professional and Scientific Relations, Procter and Gamble Pharmaceuticals Inc., Mason, OH 45040 (United States)

2005-11-11

The eye is a unique organ because of its constant exposure to radiation, atmospheric oxygen, environmental chemicals and physical abrasion. That oxidative stress mechanisms in ocular tissues have been hypothesized to play a role in diseases such as glaucoma, cataract, uveitis, retrolental fibroplasias, age-related macular degeneration and various forms of retinopathy provides an opportunity for new approaches to their prevention and treatment, In the anterior uvea, both H{sub 2}O{sub 2} and synthetic peroxides exert pharmacological/toxicological actions tissues of the anterior uvea especially on the sympathetic nerves and smooth muscles of the iris-ciliary bodies of several mammalian species. Effects produced by peroxides require the presence of trace amounts of extracellular calcium and the functional integrity of mitochondrial calcium stores. Arachidonic acid metabolites appear to be involved in both the excitatory action of peroxides on sympathetic neurotransmission and their inhibitory effect on contractility of the iris smooth muscle to muscarinic receptor activation. In addition to the peroxides, isoprostanes (products of free radical catalyzed peroxidation of arachidonic acid independent of the cyclo-oxygenase enzyme) can also alter sympathetic neurotransmission in anterior uveal tissues. In the retina, both H{sub 2}O{sub 2} and synthetic peroxides produced an inhibitory action on potassium depolarization induced release of [{sup 3}H] D-aspartate, in vitro and on the endogenous glutamate and glycine concentrations in vivo. Effects caused by peroxides in the retina are mediated, at least in part, by second messengers such as nitric oxide, prostaglandins and isoprostanes. The ability of H{sub 2}O{sub 2} to alter the integrity of neurotransmitter pools from sympathetic nerves in the anterior uvea and glutaminergic nerves in the retina could underlie its role in the etiology of glaucoma.

Electrical characteristics of GdTiO{sub 3} gate dielectric for amorphous InGaZnO thin-film transistors

Energy Technology Data Exchange (ETDEWEB)

Her, Jim-Long [Division of Natural Science, Center for General Education, Chang Gung University, Taoyuan 333, Taiwan (China); Pan, Tung-Ming, E-mail: tmpan@mail.cgu.edu.tw [Department of Electronics Engineering, Chang Gung University, Taoyuan 333, Taiwan (China); Liu, Jiang-Hung; Wang, Hong-Jun; Chen, Ching-Hung [Department of Electronics Engineering, Chang Gung University, Taoyuan 333, Taiwan (China); Koyama, Keiichi [Graduate School of Science and Engineering, Kagoshima University, Kagoshima 890-0065 (Japan)

2014-10-31

In this article, we studied the structural properties and electrical characteristics of GdTiO{sub 3} gate dielectric for amorphous indium–gallium–zinc oxide (a-IGZO) thin-film transistor (TFT) applications. The a-IGZO TFT device featuring the GdTiO{sub 3} gate dielectric exhibited better electrical characteristics, including a small threshold voltage of 0.14 V, a large field-effect mobility of 32.3 cm{sup 2}/V-s, a high I{sub on}/I{sub off} current ratio of 4.2 × 10{sup 8}, and a low subthreshold swing of 213 mV/decade. Furthermore, the electrical instability of GdTiO{sub 3} a-IGZO TFTs was investigated under both positive gate-bias stress (PGBS) and negative gate-bias stress (NGBS) conditions. The electron charge trapping in the gate dielectric dominates the PGBS degradation, while the oxygen vacancies control the NGBS degradation. - Highlights: • Indium–gallium–zinc oxide (a-IGZO) thin-film transistor (TFT) • Structural and electrical properties of the GdTiO{sub 3} film were studied. • a-IGZO TFT featuring GdTi{sub x}O{sub y} dielectric exhibited better electrical characteristics. • TFT instability investigated under positive and negative gate-bias stress conditions.

Low-voltage high-speed programming gate-all-around floating gate memory cell with tunnel barrier engineering

Science.gov (United States)

Hamzah, Afiq; Ezaila Alias, N.; Ismail, Razali

2018-06-01

The aim of this study is to investigate the memory performances of gate-all-around floating gate (GAA-FG) memory cell implementing engineered tunnel barrier concept of variable oxide thickness (VARIOT) of low-k/high-k for several high-k (i.e., Si3N4, Al2O3, HfO2, and ZrO2) with low-k SiO2 using three-dimensional (3D) simulator Silvaco ATLAS. The simulation work is conducted by initially determining the optimized thickness of low-k/high-k barrier-stacked and extracting their Fowler–Nordheim (FN) coefficients. Based on the optimized parameters the device performances of GAA-FG for fast program operation and data retention are assessed using benchmark set by 6 and 8 nm SiO2 tunnel layer respectively. The programming speed has been improved and wide memory window with 30% increment from conventional SiO2 has been obtained using SiO2/Al2O3 tunnel layer due to its thin low-k dielectric thickness. Furthermore, given its high band edges only 1% of charge-loss is expected after 10 years of ‑3.6/3.6 V gate stress.

Conotoxins Targeting Neuronal Voltage-Gated Sodium Channel Subtypes: Potential Analgesics?

Directory of Open Access Journals (Sweden)

Jeffrey R. McArthur

2012-11-01

Full Text Available Voltage-gated sodium channels (VGSC are the primary mediators of electrical signal amplification and propagation in excitable cells. VGSC subtypes are diverse, with different biophysical and pharmacological properties, and varied tissue distribution. Altered VGSC expression and/or increased VGSC activity in sensory neurons is characteristic of inflammatory and neuropathic pain states. Therefore, VGSC modulators could be used in prospective analgesic compounds. VGSCs have specific binding sites for four conotoxin families: μ-, μO-, δ- and ί-conotoxins. Various studies have identified that the binding site of these peptide toxins is restricted to well-defined areas or domains. To date, only the μ- and μO-family exhibit analgesic properties in animal pain models. This review will focus on conotoxins from the μ- and μO-families that act on neuronal VGSCs. Examples of how these conotoxins target various pharmacologically important neuronal ion channels, as well as potential problems with the development of drugs from conotoxins, will be discussed.

Voltage-gated Na+ currents in human dorsal root ganglion neurons

Science.gov (United States)

Zhang, Xiulin; Priest, Birgit T; Belfer, Inna; Gold, Michael S

2017-01-01

Available evidence indicates voltage-gated Na+ channels (VGSCs) in peripheral sensory neurons are essential for the pain and hypersensitivity associated with tissue injury. However, our understanding of the biophysical and pharmacological properties of the channels in sensory neurons is largely based on the study of heterologous systems or rodent tissue, despite evidence that both expression systems and species differences influence these properties. Therefore, we sought to determine the extent to which the biophysical and pharmacological properties of VGSCs were comparable in rat and human sensory neurons. Whole cell patch clamp techniques were used to study Na+ currents in acutely dissociated neurons from human and rat. Our results indicate that while the two major current types, generally referred to as tetrodotoxin (TTX)-sensitive and TTX-resistant were qualitatively similar in neurons from rats and humans, there were several differences that have important implications for drug development as well as our understanding of pain mechanisms. DOI: http://dx.doi.org/10.7554/eLife.23235.001 PMID:28508747

A high performance gate drive for large gate turn off thyristors

Energy Technology Data Exchange (ETDEWEB)

Szilagyi, C.P.

1993-01-01

Past approaches to gate turn-off (GTO) gating are application oriented, inefficient and dissipate power even when inactive. They allow the gate to avalanch, and do not reduce GTO turn-on and turn-off losses. A new approach is proposed which will allow modular construction and adaptability to large GTOs in the 50 amp to 2000 amp range. The proposed gate driver can be used in large voltage source and current source inverters and other power converters. The approach consists of a power metal-oxide-silicon field effect transistor (MOSFET) technology gating unit, with associated logic and supervisory circuits and an isolated flyback converter as the dc power source for the gating unit. The gate driver formed by the gating unit and the flyback converter is designed for 4000 V isolation. Control and supervisory signals are exchanged between the gate driver and the remote control system via fiber optics. The gating unit has programmable front-porch current amplitude and pulse-width, programmable closed-loop controlled back-porch current, and a turn-off switch capable of supplying negative gate current at demand as a function of peak controllable forward anode current. The GTO turn-on, turn-off and gate avalanch losses are reduced to a minimum. The gate driver itself has minimum operating losses. Analysis, design and practical realization are reported. 19 refs., 54 figs., 1 tab.

Asymmetrically thickened posterior wall is associated with decline of ejection fraction after stress on adenosine stress/rest thallium-201 gated myocardial SPECT

Energy Technology Data Exchange (ETDEWEB)

Kim, Bom Sahn; Lee, Won Woo; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul; Kim, Sang Eun [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

2004-07-01

LV parameters (LVEF. ESVI and EDVI) on adenosine stress/rest thallium-201 gated myocardial SPECT (gSPECT) are various from stress to rest. We investigated the reason why they were various in patients without coronary artery disease. Seventy-one patients(M:F=32:39, age 58.1{+-}9.7yrs), who underwent gSPECT and coronary angiography (CAG) due to chest pain or preoperative evaluation were included. CAG results were normal or insignificant. Exclusion criteria were atrial fibrillation, thyroid disease, primary cardiomyopathy, myocardial bridge, LBBB, MI, and valvular heart disease. Patients were calssified into 3 groups by EF difference ({delta}EF=rest-stress EF) on gSPECT : group1 ({delta}EF{>=}10), group2 (0 {<=}{delta}EF<10), and group3 ({delta}EF<0). LV parameters on gSPECT and thicknesses of IVS (interventricular septum) and LVPW (left ventricular posterior wall) on echocardiography were compared among the 3 groups. Myocardial perfusion status were normal or mild reversible/persistent perfusion defect in 76.1% (54/71). LVEFs at stress were not different among all 3 groups : 59.3{+-}8.54% in group 1 (61.3{+-}10.22% in group 2 and 64.8{+-}7.58% in group 3 (p>0.05). But LVEF at rest was smaller in group 3 (58.7{+-}8.38%) than the other groups (72.5{+-}8.77% in group1 and 66.7{+-}10.6% in group2) (p<0.01). EDVIs and ESVI at stress were larger than those at rest in all groups (p<0.05) except ESVI in group 3 (16.2{+-}6.21ml at stress and 17.5{+-}6.41ml at rest, p<0.01), and that was attributed to EF<0 in group 3. In echocardiographical analysis, group 3 had significantly increased wall thickness of LVPW (10.7{+-}1.2mm versus 9.4{+-}1.6mm, p=0.01) and decreased wall thickness ratio of IVS/LVPW (0.963{+-}0.102 versus 1.048{+-}0.104, p=0.035) than group 1. In patients without coronary artery disease, LVEF, EDVI and ESVI on gSPECT were various and decline of LVEF from stress to rest was caused by unnormalized ESVI . Asymmetrically thickened LVPW may play a crucial role and

Serial assessment of left ventricular function in various patient groups with Tl-201 gated myocardial perfusion SPECT

International Nuclear Information System (INIS)

Wei Lingge; Kadoya, Masumi; Momose, Mitsuhiro; Kurozumi, Masahiro; Matsushita, Tsuyoshi; Yamada, Akira

2007-01-01

The present study was performed to assess stress-related left ventricular (LV) function variations in various patient groups and to determine if they were affected by sex or the type of stress experienced. We used thallium (Tl)-201 gated myocardial perfusion single-photon emission computed tomography (SPECT) for the analysis. A total of 270 patients were examined by electrocardiography-gated myocardial perfusion SPECT imaging to assess LV function. After injection of Tl-201 at a dose of 111 MBq at peak stress, SPECT scans were acquired at 10 min (after stress) and 3 h (rest) after injection on a three-headed camera. In the normal perfusion group, the mean LV ejection fraction (LVEF) was significantly higher, and both the end-diastolic volume index (EDVI) and end-systolic volume index (ESVI) were significantly lower in women than in men (P<0.05). Poststress stunning occurred in 29 of 98 patients (30.0%) in the ischemia group and in 42 of 90 patients (46.7%) in the fixed group. There was a significant difference in poststress stunning between bicycle ergometer stress and dipyridamole stress (P<0.05). In patients with normal perfusion, LVEF, EDVI, and ESVI determined by gated Tl-201 SPECT should be corrected for sex. In addition, the influence of the type of stress should be considered when assessing stress-related LV function variations. (author)

A novel optical gating method for laser gated imaging

Science.gov (United States)

Ginat, Ran; Schneider, Ron; Zohar, Eyal; Nesher, Ofer

2013-06-01

For the past 15 years, Elbit Systems is developing time-resolved active laser-gated imaging (LGI) systems for various applications. Traditional LGI systems are based on high sensitive gated sensors, synchronized to pulsed laser sources. Elbit propriety multi-pulse per frame method, which is being implemented in LGI systems, improves significantly the imaging quality. A significant characteristic of the LGI is its ability to penetrate a disturbing media, such as rain, haze and some fog types. Current LGI systems are based on image intensifier (II) sensors, limiting the system in spectral response, image quality, reliability and cost. A novel propriety optical gating module was developed in Elbit, untying the dependency of LGI system on II. The optical gating module is not bounded to the radiance wavelength and positioned between the system optics and the sensor. This optical gating method supports the use of conventional solid state sensors. By selecting the appropriate solid state sensor, the new LGI systems can operate at any desired wavelength. In this paper we present the new gating method characteristics, performance and its advantages over the II gating method. The use of the gated imaging systems is described in a variety of applications, including results from latest field experiments.

Patient-reported outcomes in post-traumatic stress disorder Part II: Focus on pharmacological treatment

Science.gov (United States)

Kapfhammer, Hans-Peter

2014-01-01

Post-traumatic stress disorder (PTSD) may be associated with long-lasting psychological suffering, distressing psychosocial disability, markedly reduced health-related quality of life, and increased morbidity and mortality in a subgroup of individuals in the aftermath of serious traumatic events. Both etiopathogenesis and treatment modalities of PTSD are best conceptualized within a biopsychosotial model. Pharmacotherapy may lay claim to a major role in the multimodal treatment approaches. Here we outline two different pharmacotherapeutic trends that aim to modify the encoding, consolidation, and rehearsal of traumatic memory in order to reduce the risk of PTSD immediately after trauma exposure on the one hand, and that endeavor to treat the clinical state of PTSD on the other. The theoretical rationales of both pharmacological strategies are the complex neurobiological underpinnings that characterize traumatic memory organization and clinical PTSD. Meanwhile, promising data from randomized controlled trials have been obtained for both approaches. Empirical evidence may inform clinicians in their clinical efforts for this special group of patients. The efficacy of several classes of drugs that have been investigated within a context of research should be evaluated critically and still have to stand the test of effectiveness in daily clinical practice. From a patient perspective, empirical results may serve as a psychoeducative guideline to what pharmacotherapeutic approaches may realistically achieve, what their risks and benefits are, and what their limits are in contributing to reducing the often major chronic suffering caused by serious traumatic events. Ethical issues have to be considered, particularly in the context of pharmacological strategies projected to prevent PTSD in the aftermath of traumatic exposure. PMID:25152660

Evaluation of left ventricular ejection fraction using quantitative gated SPECT (QGS)

International Nuclear Information System (INIS)

Musa, M. A. A.

2010-07-01

Electrocardiographic ally gated myocardial perfusion SPECT (G SPECT) is a state-of the art technique for the combined evaluation of myocardial perfusion and left ventricular function within a single study. It is currently one of the most commonly performed cardiology procedures in a nuclear medicine department. Automation of the image processing and quantification has made this techniques highly reproducible, practical and user friendly in the clinical setting . In patients with coronary artery disease, gating enhances the diagnostic and prognostic capability of myocardial perfusion imaging provides incremental information over the the perfusion data, and has shown potentials for myocardial viability assessment and sequential follow-up after therapy. Evaluation of the left ventricular (L V) function is important in clinical cardiology. Quantifying the degree and extent of the L V functional abnormalities permits a systematic assessment of the disease process on the myocardial performance. The aim of this thesis is to evaluate left ventricular ejection fraction (LVEF) in patients with no evidence of ischemic response during the stress test. This investigation was carried out in view of the few reports concerning the findings ventricular function with gated SPECT in these situations in the normal population, which is relevant when considering the possibility of myocardial stunning. Method: We prospectively studied 30 selected patients, in difference age and gender. A one-day protocol was used, with injection 555 MBq - 1.11 MBq (15 - 30 mCi) of 99 mTc-M1 B1 at stress and rest. Gated perfusion SPECT was acquired 30 to 60 minutes after radiotracer injection in both condition and processed using QGSPECT software. Difference between stress and rest LVEF was calculated. Result and conclusion: rest LVEF was higher in the stress (exercise) group, A trend line was done in both groups and r-value was (0.9) and p=0.04 in acceptance value. Standard deviation of LVEF also was

ECG-gated myocardial imaging with 201Tl

International Nuclear Information System (INIS)

Baehre, M.

1980-01-01

ECG-gated myocardial scintigraphy by means of 201 TI was performed in 11 patients. Good scintigrams could be gained by using long imaging times, but there was no additional information when compared with static images. Disadvantages were long imaging time, higher technical expenditure, and the smaller number of projections. Furthermore, there is no possibility of performing myocardial imaging under stress. (orig.) [de

Dynamic gating window for compensation of baseline shift in respiratory-gated radiation therapy

International Nuclear Information System (INIS)

Pepin, Eric W.; Wu Huanmei; Shirato, Hiroki

2011-01-01

Purpose: To analyze and evaluate the necessity and use of dynamic gating techniques for compensation of baseline shift during respiratory-gated radiation therapy of lung tumors. Methods: Motion tracking data from 30 lung tumors over 592 treatment fractions were analyzed for baseline shift. The finite state model (FSM) was used to identify the end-of-exhale (EOE) breathing phase throughout each treatment fraction. Using duty cycle as an evaluation metric, several methods of end-of-exhale dynamic gating were compared: An a posteriori ideal gating window, a predictive trend-line-based gating window, and a predictive weighted point-based gating window. These methods were evaluated for each of several gating window types: Superior/inferior (SI) gating, anterior/posterior beam, lateral beam, and 3D gating. Results: In the absence of dynamic gating techniques, SI gating gave a 39.6% duty cycle. The ideal SI gating window yielded a 41.5% duty cycle. The weight-based method of dynamic SI gating yielded a duty cycle of 36.2%. The trend-line-based method yielded a duty cycle of 34.0%. Conclusions: Dynamic gating was not broadly beneficial due to a breakdown of the FSM's ability to identify the EOE phase. When the EOE phase was well defined, dynamic gating showed an improvement over static-window gating.

Criteria for definition of regional functional improvement on quantitative post-stress gated myocardial SPET after bypass surgery in patients with ischaemic cardiomyopathy

International Nuclear Information System (INIS)

Lee, Dong Soo; Cheon, Gi Jeong; Paeng, Jin Chul; Chung, June-Key; Lee, Myung Chul; Kim, Ki Bong

2002-01-01

Myocardial viability can be defined as functional improvement of dysfunctional myocardium after revascularization. The purpose of this study was to define the optimal criteria for definition of regional functional improvement after coronary artery bypass graft (CABG) surgery on quantitative gated single-photon emission tomography (SPET). Thirty-two patients (26 men, 6 women; age 56±13 years) with coronary artery disease (three-vessel disease, 17; two-vessel disease, 15; previous history of myocardial infarction, 9) and severe left ventricular dysfunction (LVEF≤35%) underwent CABG. Rest thallium-201/dipyridamole stress technetium-99m methoxyisobutylisonitrile gated myocardial SPET was performed before and 3 months after CABG. Global LV functional improvement was defined as either an improvement in LVEF of 10% (n=15) or an improvement in LVEF of 5% combined with a decrease in end-systolic volume of 10 ml (n=2) after CABG on quantitative gated SPET. Postoperative regional wall thickening improvement (ΔRWT), regional wall motion improvement (ΔRWM) and regional resting (ΔRP) and stress perfusion improvement (ΔRstrP) were used to determine global functional improvement by ROC curve analysis, and the optimal criteria for definition of viable regional dysfunctional myocardium were defined on the ROC curves. Correlations were verified by determining the number of improved myocardial regions and LVEF improvement. LVEF was improved from 25%±6% to 34%±11% after CABG. A total of 229 segments were dysfunctional (wall motion ≤2 mm, thickening ≤20%) before CABG. On ROC curve analysis using global functional improvement as an indicator of viability, the areas under the ROC curves (AUCs) of ΔRWT and ΔRWM were 0.717 and 0.620, respectively. The AUC of ΔRWT was significantly larger than that of ΔRWM (P=0.009) and the optimal cut-off value of ΔRWT was 15%. The AUCs of ΔRP and ΔRstrP were not significant. The correlation coefficients between summed ΔRWT and �

Vasodilator stress impairs the left ventricular function obtained with gated single-photon emission computed tomography in patients with known or suspected coronary artery disease

International Nuclear Information System (INIS)

Odagiri, Keiichi; Uehara, Akihiko; Kurata, Chinori

2010-01-01

Transient ischemic dilatation (TID) and post-stress dysfunction of the left ventricle (LV) are important markers of severe coronary artery disease (CAD). To clarify the effects of stressor type on TID and post-stress LV dysfunction, changes in LV measurements were compared between patients with exercise- or vasodilator-induced stress. The 689 patients referred for technetium-99m tetrofosmin myocardial perfusion imaging were included. Patients were stressed with either a vasodilator (n=236) or exercise (n=453). LV measurements were obtained with electrocardiogram (ECG)-gated single photon emission computed tomography (SPECT). LV end-diastolic and end-systolic volume indexes (LVEDVI, LVESVI) increased and LV ejection fraction (LVEF) decreased after stress in the vasodilator-stress group. Vasodilator-stress and the summed difference score (SDS) were independent variables that decreased LVEF after stress. Even in patients without reversible defects, vasodilator-stress impaired LV function. There were no differences in the stress-to-rest ratios of LVEDVI (rEDV) and LVESVI (rESV) among patients with normal myocardial perfusion, fixed defects and reversible defects in the vasodilator-stress group, whereas in the exercise-stress group, rESV was significantly higher in the patients with reversible defects than in those without reversible defects. Within the vasodilator-stress group, neither rEDV nor rESV correlated with the SDS. Vasodilator-stress by itself decreases LVEF after stress. TID should be carefully interpreted when vasodilator-stress is used to detect severe CAD. (author)

The effect of D1 receptor on sensorimotor gating in animal model of schizophrenia-like behavior

Czech Academy of Sciences Publication Activity Database

Bubeníková-Valešová, V.; Valeš, Karel; Svoboda, Jan; Páleníček, T.; Horáček, J.

2007-01-01

Roč. 18, Suppl.1 (2007), S69-S70 ISSN 0955-8810. [Biennial Meeting of the European Behavioural Pharmacology Society /12./. 31.08.2007-03.09.2007, Tübingen] R&D Projects: GA MŠk(CZ) 1M0517; GA ČR(CZ) GA309/07/0341; GA MZd(CZ) NR9178 Institutional research plan: CEZ:AV0Z50110509 Keywords : dopamine * sensorimotor gating Subject RIV: FH - Neurology

Stress: Neurobiology, consequences and management

Directory of Open Access Journals (Sweden)

Anil Kumar

2013-01-01

Full Text Available Stress, both physical and psychological, is attracting increasing attention among neuroresearchers. In the last 20 decades, there has been a surge of interest in the research of stress-induced manifestations and this approach has resulted in the development of more appropriate animal models for stress-associated pathologies and its therapeutic management. These stress models are an easy and convenient method for inducing both psychological and physical stress. To understand the behavioral changes underlying major depression, molecular and cellular studies are required. Dysregulation of the stress system may lead to disturbances in growth and development, and may this may further lead to the development of various other psychiatric disorders. This article reviews the different types of stress and their neurobiology, including the different neurotransmitters affected. There are various complications associated with stress and their management through various pharmacological and non-pharmacological techniques. The use of herbs in the treatment of stress-related problems is practiced in both Indian and Western societies, and it has a vast market in terms of anti-stress medications and treatments. Non-pharmacological techniques such as meditation and yoga are nowadays becoming very popular as a stress-relieving therapy because of their greater effectiveness and no associated side effects. Therefore, this review highlights the changes under stress and stressor and their impact on different animal models in understanding the mechanisms of stress along with their effective and safe management.

Normal value of functional parameters in gated myocardial perfusion SPECT in patients with low risk of coronary artery disease: emory cardiac tool box program

Energy Technology Data Exchange (ETDEWEB)

Kang, D. Y.; Kim, M. H.; Kim, Y. D.; Kim, D. K. [Donga University College of Medicine, Busan (Korea, Republic of)

2002-07-01

Absolute value of the functional data of gated myocardial perfusion SPECT is necessary to determine that individual patient is normal or not. Tc-99m MIBI gated myocardial perfusion SPECT was performed using emory cardiac tool box program. All patients (M:F=15:36, age 64{+-}10 yrs) showed normal myocardial perfusion. The patients with following characteristics were excluded; previous angina or MI, ECG change with Q wave or ST-T change, diabetes mellitus, hypercholesterolemia, typical chest pain and hypertension. In all patients, myocardial mass is 117{+-}23 g in stress gated SPECT, 106{+-}22 g in stress ungated SPECT and 102{+-}21 g in rest ungated SPECT. EDV is 90{+-}28 ml, ESV 26{+-}20 ml, SV 66{+-}21 ml, EF 73{+-}10 % and TID 1.06{+-}0.14. Myocardial mass in rest ungated SPECT is significantly different between men and women (p=0.025). Myocardial mass is significantly different between stress gated SPECT and stress ungated SPECT (p=0.000), and between stress ungated SPECT and rest ungated SPECT (p=0.003). We provide normal value of functional parameters to determine the abnormality of individual patients in patients with low risk of coronary artery disease.

Left ventricular functional parameters by gated SPECT myocardial perfusion imaging in a Latin American country.

Science.gov (United States)

Kapitan, Miguel; Beltran, Alvaro; Beretta, Mario; Mut, Fernando

2018-04-01

There is paucity of data on left ventricular (LV) functional parameters using gated SPECT myocardial perfusion imaging (MPI) from the Latin American region. This study provides detailed information in low-risk patients both at rest and during exercise. We studied 90 patients (50 men) with a very low likelihood of coronary artery disease. Gated-SPECT MPI was performed with Tc-99m MIBI using a 2-day protocol, with 16 frames/R-R cycle. The LV ejection fraction and volumes were not different between the rest and post-stress images. LVEF was 68 ± 7% post-stress and 70 ± 7% at rest in women, and 62 ± 7% and 63 ± 7%, respectively, in men (P = .19, .26). LV volumes were larger in men than women (P stress. Transient ischemic dilatation was similar, with upper limits of 1.20 and 1.19 in women and men, respectively (P = NS). These data could prove helpful for the interpretation of gated SPECT MPI data in Latin America using identical protocol as used in this study.

Stress echocardiography expert consensus statement

NARCIS (Netherlands)

R. Sicari (Rosa); P. Nihoyannopoulos (Petros); A. Evangelista (Arturo); J. Kasprzak (Jaroslav); P. Lancellotti (Patrizio); D. Poldermans (Don); J.U. Voigt; J.L. Zamorano (Jose)

2008-01-01

textabstractStress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography

Synthesis and Pharmacology of Halogenated δ-Opioid-Selective [D-Ala2]Deltorphin II Peptide Analogues

Science.gov (United States)

Pescatore, Robyn; Marrone, Gina F.; Sedberry, Seth; Vinton, Daniel; Finkelstein, Netanel; Katlowitz, Yitzchak E.; Pasternak, Gavril W.; Wilson, Krista R.; Majumdar, Susruta

2015-01-01

Deltorphins are naturally occurring peptides produced by the skin of the giant monkey frog (Phyllomedusa bicolor). They are δ-opioid receptor-selective agonists. Herein, we report the design and synthesis of a peptide, Tyr-D-Ala-(pI)Phe-Glu-Ile-Ile-Gly-NH2 3 (GATE3-8), based on the [D-Ala2]deltorphin II template, which is δ-selective in in vitro radioligand binding assays over the μ- and κ-opioid receptors. It is a full agonist in [35S]GTPγS functional assays and analgesic when administered supraspinally to mice. Analgesia of 3 (GATE3-8) is blocked by the selective δ receptor antagonist naltrindole, indicating that the analgesic action of 3 is mediated by the δ-opioid receptor. We have established a radioligand in which 125I isincorporated into 3 (GATE3-8). The radioligand has a KD of 0.1 nM in Chinese hamster ovary (CHO) cells expressing the δ receptor. Additionally, a series of peptides based on 3 (GATE3-8) was synthesized by incorporating various halogens in the para position on the aromatic ring of Phe3. The peptides were characterized for binding affinity at the μ-, δ-, and κ-opioid receptors, which showed a linear correlation between binding affinity and the size of the halogen substituent. These peptides may be interesting tools for probing δ-opioid receptor pharmacology. PMID:25844930

Synthesis and pharmacology of halogenated δ-opioid-selective [d-Ala(2)]deltorphin II peptide analogues.

Science.gov (United States)

Pescatore, Robyn; Marrone, Gina F; Sedberry, Seth; Vinton, Daniel; Finkelstein, Netanel; Katlowitz, Yitzchak E; Pasternak, Gavril W; Wilson, Krista R; Majumdar, Susruta

2015-06-17

Deltorphins are naturally occurring peptides produced by the skin of the giant monkey frog (Phyllomedusa bicolor). They are δ-opioid receptor-selective agonists. Herein, we report the design and synthesis of a peptide, Tyr-d-Ala-(pI)Phe-Glu-Ile-Ile-Gly-NH2 3 (GATE3-8), based on the [d-Ala(2)]deltorphin II template, which is δ-selective in in vitro radioligand binding assays over the μ- and κ-opioid receptors. It is a full agonist in [(35)S]GTPγS functional assays and analgesic when administered supraspinally to mice. Analgesia of 3 (GATE3-8) is blocked by the selective δ receptor antagonist naltrindole, indicating that the analgesic action of 3 is mediated by the δ-opioid receptor. We have established a radioligand in which (125)I is incorporated into 3 (GATE3-8). The radioligand has a KD of 0.1 nM in Chinese hamster ovary (CHO) cells expressing the δ receptor. Additionally, a series of peptides based on 3 (GATE3-8) was synthesized by incorporating various halogens in the para position on the aromatic ring of Phe(3). The peptides were characterized for binding affinity at the μ-, δ-, and κ-opioid receptors, which showed a linear correlation between binding affinity and the size of the halogen substituent. These peptides may be interesting tools for probing δ-opioid receptor pharmacology.

Linear gate

International Nuclear Information System (INIS)

Suwono.

1978-01-01

A linear gate providing a variable gate duration from 0,40μsec to 4μsec was developed. The electronic circuity consists of a linear circuit and an enable circuit. The input signal can be either unipolar or bipolar. If the input signal is bipolar, the negative portion will be filtered. The operation of the linear gate is controlled by the application of a positive enable pulse. (author)

Pharmacological interventions for preventing post-traumatic stress disorder (PTSD).

Science.gov (United States)

Amos, Taryn; Stein, Dan J; Ipser, Jonathan C

2014-07-08

Post-traumatic stress disorder (PTSD) is a debilitating disorder which, after a sufficient delay, may be diagnosed amongst individuals who respond with intense fear, helplessness or horror to traumatic events. There is some evidence that the use of pharmacological interventions immediately after exposure to trauma may reduce the risk of developing of PTSD. To assess the effects of pharmacological interventions for the prevention of PTSD in adults following exposure to a traumatic event. We searched the Cochrane Depression, Anxiety and Neurosis Controlled Trials Register (CCDANCTR-Studies and CCDANCTR-References) (to 14 February 2014). This register contains relevant reports of randomised controlled trials from the following bibliographic databases: CENTRAL (all years); EMBASE (1974 to date); MEDLINE (1950 to date) and PsycINFO (1967 to date). We identified unpublished trials by searching the National Institute of Health (NIH) Reporter, the metaRegister of Controlled Trials database (mRCT) and the WHO International Clinical Trials Registry Platform (to December 2013). We scanned the reference lists of articles for additional studies. We placed no constraints on language and setting. We restricted studies to randomised controlled trials (RCTs) of pharmacological interventions compared with placebo for the prevention of PTSD in adults. Two authors (TA and JI) independently assessed trials for eligibility and inclusion based on the review selection criteria. We independently extracted sample, methodological, outcome and 'Risk of bias' data, as well as the number of side effects, from each trial and entered these into a customised data extraction form. We contacted investigators for missing information. We calculated summary statistics for continuous and dichotomous variables (if provided). We did not undertake subgroup analyses due to the small number of included studies. We included nine short-term RCTs (duration 12 weeks or less) in the analysis (345 participants

Pharmacological enhancement of exposure-based treatment in PTSD: a qualitative review

Directory of Open Access Journals (Sweden)

Rianne A. de Kleine

2013-10-01

Full Text Available There is a good amount of evidence that exposure therapy is an effective treatment for posttraumatic stress disorder (PTSD. Notwithstanding its efficacy, there is room for improvement, since a large proportion of patients does not benefit from treatment. Recently, an interesting new direction in the improvement of exposure therapy efficacy for PTSD emerged. Basic research found evidence of the pharmacological enhancement of the underlying learning and memory processes of exposure therapy. The current review aims to give an overview of clinical studies on pharmacological enhancement of exposure-based treatment for PTSD. The working mechanisms, efficacy studies in PTSD patients, and clinical utility of four different pharmacological enhancers will be discussed: D-cycloserine, MDMA, hydrocortisone, and propranolol.

Pharmacological enhancement of exposure-based treatment in PTSD: a qualitative review.

Science.gov (United States)

de Kleine, Rianne A; Rothbaum, Barbara O; van Minnen, Agnes

2013-10-17

There is a good amount of evidence that exposure therapy is an effective treatment for posttraumatic stress disorder (PTSD). Notwithstanding its efficacy, there is room for improvement, since a large proportion of patients does not benefit from treatment. Recently, an interesting new direction in the improvement of exposure therapy efficacy for PTSD emerged. Basic research found evidence of the pharmacological enhancement of the underlying learning and memory processes of exposure therapy. The current review aims to give an overview of clinical studies on pharmacological enhancement of exposure-based treatment for PTSD. The working mechanisms, efficacy studies in PTSD patients, and clinical utility of four different pharmacological enhancers will be discussed: d-cycloserine, MDMA, hydrocortisone, and propranolol.

Acanthopanax senticosus: review of botany, chemistry and pharmacology.

Science.gov (United States)

Huang, Linzhang; Zhao, Hongfang; Huang, Baokang; Zheng, Chengjian; Peng, Wei; Qin, Luping

2011-02-01

Acanthopanax senticosus (Rupr. et Maxim) Harms (Araliaceae), also called Siberian Ginseng, Eleutherococcus senticosus, and Ciwujia in Chinese, is a widely used traditional Chinese herb that could invigorate qi, strengthen the spleen, and nourish kidney in the theory of Traditional Chinese Medicine. With high medicinal value, Acanthopanax senticosus (AS, thereafter) is popularly used as an "adaptogen" like Panax ginseng. In recent decades, a great number of chemical, pharmacological, and clinical studies on AS have been carried out worldwide. Several kinds of chemical compounds have been reported, including triterpenoid saponins, lignans, coumarins, and flavones, among which, phenolic compounds such as syringin and eleutheroside E, were considered to be the most active components. Considerable pharmacological experiments both in vitro and in vivo have persuasively demonstrated that AS possessed anti-stress, antiulcer, anti-irradiation, anticancer, anti-inflammatory and hepatoprotective activities, etc. The present review is an up-to-date and comprehensive analysis of the botany, chemistry, pharmacology, toxicity and clinical trials of AS.

New gate opening hours

CERN Multimedia

GS Department

2009-01-01

Please note the new opening hours of the gates as well as the intersites tunnel from the 19 May 2009: GATE A 7h - 19h GATE B 24h/24 GATE C 7h - 9h\t17h - 19h GATE D 8h - 12h\t13h - 16h GATE E 7h - 9h\t17h - 19h Prévessin 24h/24 The intersites tunnel will be opened from 7h30 to 18h non stop. GS-SEM Group Infrastructure and General Services Department

ISAC's Gating-ML 2.0 data exchange standard for gating description.

Science.gov (United States)

Spidlen, Josef; Moore, Wayne; Brinkman, Ryan R

2015-07-01

The lack of software interoperability with respect to gating has traditionally been a bottleneck preventing the use of multiple analytical tools and reproducibility of flow cytometry data analysis by independent parties. To address this issue, ISAC developed Gating-ML, a computer file format to encode and interchange gates. Gating-ML 1.5 was adopted and published as an ISAC Candidate Recommendation in 2008. Feedback during the probationary period from implementors, including major commercial software companies, instrument vendors, and the wider community, has led to a streamlined Gating-ML 2.0. Gating-ML has been significantly simplified and therefore easier to support by software tools. To aid developers, free, open source reference implementations, compliance tests, and detailed examples are provided to stimulate further commercial adoption. ISAC has approved Gating-ML as a standard ready for deployment in the public domain and encourages its support within the community as it is at a mature stage of development having undergone extensive review and testing, under both theoretical and practical conditions. © 2015 International Society for Advancement of Cytometry.

Determination of prospective displacement-based gate threshold for respiratory-gated radiation delivery from retrospective phase-based gate threshold selected at 4D CT simulation

International Nuclear Information System (INIS)

Vedam, S.; Archambault, L.; Starkschall, G.; Mohan, R.; Beddar, S.

2007-01-01

Four-dimensional (4D) computed tomography (CT) imaging has found increasing importance in the localization of tumor and surrounding normal structures throughout the respiratory cycle. Based on such tumor motion information, it is possible to identify the appropriate phase interval for respiratory gated treatment planning and delivery. Such a gating phase interval is determined retrospectively based on tumor motion from internal tumor displacement. However, respiratory-gated treatment is delivered prospectively based on motion determined predominantly from an external monitor. Therefore, the simulation gate threshold determined from the retrospective phase interval selected for gating at 4D CT simulation may not correspond to the delivery gate threshold that is determined from the prospective external monitor displacement at treatment delivery. The purpose of the present work is to establish a relationship between the thresholds for respiratory gating determined at CT simulation and treatment delivery, respectively. One hundred fifty external respiratory motion traces, from 90 patients, with and without audio-visual biofeedback, are analyzed. Two respiratory phase intervals, 40%-60% and 30%-70%, are chosen for respiratory gating from the 4D CT-derived tumor motion trajectory. From residual tumor displacements within each such gating phase interval, a simulation gate threshold is defined based on (a) the average and (b) the maximum respiratory displacement within the phase interval. The duty cycle for prospective gated delivery is estimated from the proportion of external monitor displacement data points within both the selected phase interval and the simulation gate threshold. The delivery gate threshold is then determined iteratively to match the above determined duty cycle. The magnitude of the difference between such gate thresholds determined at simulation and treatment delivery is quantified in each case. Phantom motion tests yielded coincidence of simulation

Bias-stress characterization of solution-processed organic field-effect transistor based on highly ordered liquid crystals

Science.gov (United States)

Kunii, M.; Iino, H.; Hanna, J.

2017-06-01

Bias-stress effects in solution-processed, 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10) field effect transistors (FETs) are studied under negative and positive direct current bias. The bottom gate, bottom contact polycrystalline Ph-BTBT-10 FET with a hybrid gate dielectric of polystyrene and SiO2 shows high field effect mobility as well as a steep subthreshold slope when fabricated with a highly ordered smectic E liquid crystalline (SmE) film as a precursor. Negative gate bias-stress causes negative threshold voltage shift (ΔVth) for Ph-BTBT-10 FET in ambient air, but ΔVth rapidly decreases as the gate bias decreases and approaches to near zero when the gate bias goes down to 9 V in amplitude. In contrast, positive gate bias-stress causes negligible ΔVth even with a relatively high bias voltage. These results conclude that Ph-BTBT-10 FET has excellent bias-stress stability in ambient air in the range of low to moderate operating voltages.

A gate-latch-lock mechanism for hormone signalling by abscisic acid receptors

KAUST Repository

Melcher, Karsten

2009-12-03

Abscisic acid (ABA) is a ubiquitous hormone that regulates plant growth, development and responses to environmental stresses. Its action is mediated by the PYR/PYL/RCAR family of START proteins, but it remains unclear how these receptors bind ABA and, in turn, how hormone binding leads to inhibition of the downstream type 2C protein phosphatase (PP2C) effectors. Here we report crystal structures of apo and ABA-bound receptors as well as a ternary PYL2-ABA-PP2C complex. The apo receptors contain an open ligand-binding pocket flanked by a gate that closes in response to ABA by way of conformational changes in two highly conserved ?-loops that serve as a gate and latch. Moreover, ABA-induced closure of the gate creates a surface that enables the receptor to dock into and competitively inhibit the PP2C active site. A conserved tryptophan in the PP2C inserts directly between the gate and latch, which functions to further lock the receptor in a closed conformation. Together, our results identify a conserved gate-latch-lock mechanism underlying ABA signalling. © 2009 Macmillan Publishers Limited. All rights reserved.

A gate-latch-lock mechanism for hormone signalling by abscisic acid receptors

KAUST Repository

Melcher, Karsten; Ng, Ley-Moy; Zhou, X. Edward; Soon, Fen-Fen; Xu, Yong; Suino-Powell, Kelly M.; Park, Sang-Youl; Weiner, Joshua J.; Fujii, Hiroaki; Chinnusamy, Viswanathan; Kovach, Amanda; Li, Jun; Wang, Yonghong; Li, Jiayang; Peterson, Francis C.; Jensen, Davin R.; Yong, Eu-Leong; Volkman, Brian F.; Cutler, Sean R.; Zhu, Jian-Kang; Xu, H. Eric

2009-01-01

Abscisic acid (ABA) is a ubiquitous hormone that regulates plant growth, development and responses to environmental stresses. Its action is mediated by the PYR/PYL/RCAR family of START proteins, but it remains unclear how these receptors bind ABA and, in turn, how hormone binding leads to inhibition of the downstream type 2C protein phosphatase (PP2C) effectors. Here we report crystal structures of apo and ABA-bound receptors as well as a ternary PYL2-ABA-PP2C complex. The apo receptors contain an open ligand-binding pocket flanked by a gate that closes in response to ABA by way of conformational changes in two highly conserved ?-loops that serve as a gate and latch. Moreover, ABA-induced closure of the gate creates a surface that enables the receptor to dock into and competitively inhibit the PP2C active site. A conserved tryptophan in the PP2C inserts directly between the gate and latch, which functions to further lock the receptor in a closed conformation. Together, our results identify a conserved gate-latch-lock mechanism underlying ABA signalling. © 2009 Macmillan Publishers Limited. All rights reserved.

BDNF Val66Met Genotype Interacts With a History of Simulated Stress Exposure to Regulate Sensorimotor Gating and Startle Reactivity.

Science.gov (United States)

Notaras, Michael J; Hill, Rachel A; Gogos, Joseph A; van den Buuse, Maarten

2017-05-01

Reduced expression of Brain-Derived Neurotrophic Factor (BDNF) has been implicated in the pathophysiology of schizophrenia. The BDNF Val66Met polymorphism, which results in deficient activity-dependent secretion of BDNF, is associated with clinical features of schizophrenia. We investigated the effect of this polymorphism on Prepulse Inhibition (PPI), a translational model of sensorimotor gating which is disrupted in schizophrenia. We utilized humanized BDNFVal66Met (hBDNFVal66Met) mice which have been modified to carry the Val66Met polymorphism, as well as express humanized BDNF in vivo. We also studied the long-term effect of chronic corticosterone (CORT) exposure in these animals as a model of history of stress. PPI was assessed at 30ms and 100ms interstimulus intervals (ISI). Analysis of PPI at the commonly used 100ms ISI identified that, irrespective of CORT treatment, the hBDNFVal/Met genotype was associated with significantly reduced PPI. In contrast, PPI was not different between hBDNFMet/Met and hBDNFVal/Val genotype mice. At the 30ms ISI, CORT treatment selectively disrupted sensorimotor gating of hBDNFVal/Met heterozygote mice but not hBDNFVal/Val or hBDNFMet/Met mice. Analysis of startle reactivity revealed that chronic CORT reduced startle reactivity of hBDNFVal/Val male mice by 51%. However, this was independent of the effect of CORT on PPI. In summary, we provide evidence of a distinct BDNFVal66Met heterozygote-specific phenotype using the sensorimotor gating endophenotype of schizophrenia. These data have important implications for clinical studies where, if possible, the BDNFVal/Met heterozygote genotype should be distinguished from the BDNFMet/Met genotype. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Dysfunctional Hyperpolarization-Activated Cyclic Nucleotide-gated Ion Channels in Cardiac Diseases

Directory of Open Access Journals (Sweden)

Xiaoqi Zhao

Full Text Available Abstract Hyperpolarization-activated cyclic nucleotide-gated (HCN channels are reverse voltage-dependent, and their activation depends on the hyperpolarization of the membrane and may be directly or indirectly regulated by the cyclic adenosine monophosphate (cAMP or other signal-transduction cascades. The distribution, quantity and activation states of HCN channels differ in tissues throughout the body. Evidence exhibits that HCN channels play critical roles in the generation and conduction of the electrical impulse and the physiopathological process of some cardiac diseases. They may constitute promising drug targets in the treatment of these cardiac diseases. Pharmacological treatment targeting HCN channels is of benefit to these cardiac conditions.

Non-adherence to pharmacological treatment in schizophrenia and schizophrenia spectrum disorders

DEFF Research Database (Denmark)

Ljungdalh, P. M.

2017-01-01

Background and objectives The primary treatment for schizophrenia and schizophrenia-spectrum disorders is antipsychotic medication. One of the many public health challenges in mental illness, is to identify contributing factors to non-adherence to pharmacological treatment. The objective...... of this study was to perform an updated systematic review of risk factors for non-adherence to pharmacological treatment in schizophrenia in a European and American context. Methods The study was a systematic literature review of studies that included at least two measurements of pharmacological adherence...... of illness, alcohol or drug abuse and unspecified younger age. Conclusions The findings in this systematic literature review are consistent with previous reviews on non-adherence and schizophrenia. It stresses the methodological challenges in psychiatric adherence research and establishes the need for more...

State-dependent changes in auditory sensory gating in different cortical areas in rats.

Directory of Open Access Journals (Sweden)

Renli Qi

Full Text Available Sensory gating is a process in which the brain's response to a repetitive stimulus is attenuated; it is thought to contribute to information processing by enabling organisms to filter extraneous sensory inputs from the environment. To date, sensory gating has typically been used to determine whether brain function is impaired, such as in individuals with schizophrenia or addiction. In healthy subjects, sensory gating is sensitive to a subject's behavioral state, such as acute stress and attention. The cortical response to sensory stimulation significantly decreases during sleep; however, information processing continues throughout sleep, and an auditory evoked potential (AEP can be elicited by sound. It is not known whether sensory gating changes during sleep. Sleep is a non-uniform process in the whole brain with regional differences in neural activities. Thus, another question arises concerning whether sensory gating changes are uniform in different brain areas from waking to sleep. To address these questions, we used the sound stimuli of a Conditioning-testing paradigm to examine sensory gating during waking, rapid eye movement (REM sleep and Non-REM (NREM sleep in different cortical areas in rats. We demonstrated the following: 1. Auditory sensory gating was affected by vigilant states in the frontal and parietal areas but not in the occipital areas. 2. Auditory sensory gating decreased in NREM sleep but not REM sleep from waking in the frontal and parietal areas. 3. The decreased sensory gating in the frontal and parietal areas during NREM sleep was the result of a significant increase in the test sound amplitude.

A Very Robust AlGaN/GaN HEMT Technology to High Forward Gate Bias and Current

Directory of Open Access Journals (Sweden)

Bradley D. Christiansen

2012-01-01

Full Text Available Reports to date of GaN HEMTs subjected to forward gate bias stress include varied extents of degradation. We report an extremely robust GaN HEMT technology that survived—contrary to conventional wisdom—high forward gate bias (+6 V and current (>1.8 A/mm for >17.5 hours exhibiting only a slight change in gate diode characteristic, little decrease in maximum drain current, with only a 0.1 V positive threshold voltage shift, and, remarkably, a persisting breakdown voltage exceeding 200 V.

Gate current for p+-poly PMOS devices under gate injection conditions

NARCIS (Netherlands)

Hof, A.J.; Holleman, J.; Woerlee, P.H.

2001-01-01

In current CMOS processing both n+-poly and p+-poly gates are used. The I-V –relationship and reliability of n+-poly devices are widely studied and well understood. Gate currents and reliability for p+-poly PMOS devices under gate injection conditions are not well understood. In this paper, the

The value of regional wall motion abnormalities on 99Tcm-MIBI gated cardiac SPECT in predicting angiographic stenoses of coronary artery

International Nuclear Information System (INIS)

Li Dianfu; Huang Jun; Zhu Tiebing; Wang Liansheng; Yang Zhijian; Feng Jianlin; Li Jianhua; Chen Jianwei; Chang Guojun

2004-01-01

Objective: To determine the magnitude of angiographic stenoses of coronary artery in reversible regional wall motion abnormalities (RWMA) present in exercise stress 99 Tc m -methoxyisobutylisonitrile (MIBI) gated SPECT myocardial perfusion imaging (MPI). Methods: One hundred and sixteen patients undergoing coronary angiography two weeks before and after the exercise stress 99 Tc m -MIBI gated SPECT MPI. Images were acquired 15 to 20 min after stress. A five grades and twenty segments marking system was introduced to assess the RWMA and thickening of left ventricles. Results: The sensitivity of reversible RWMA for detecting ≥75% angiographic stenoses was 65%, with a specificity of 97%. Reversible RWMA has a high positive predictive value (98%) for stratification between severe angiographic stenoses of 75% and non-severe stenoses (less than 75%). Multivariate analysis showed that the post-stress wall motion (SSSWM), exercise wall motion differentiation value (SDSWM) and summed stress score (SSS) were the independent risk factor of coronary artery jeopardy score. Conclusions: Reversible RWMA, as shown by exercise stress 99 Tc m -MIBI gated SPECT MPI, is a significant predictor of angiographic disease with very high specificity and positive predictive values. Exercise reversible RWMA can rise the assessment value of angiographic severity in MPI

Molecular Basis of Cardiac Delayed Rectifier Potassium Channel Function and Pharmacology.

Science.gov (United States)

Wu, Wei; Sanguinetti, Michael C

2016-06-01

Human cardiomyocytes express 3 distinct types of delayed rectifier potassium channels. Human ether-a-go-go-related gene (hERG) channels conduct the rapidly activating current IKr; KCNQ1/KCNE1 channels conduct the slowly activating current IKs; and Kv1.5 channels conduct an ultrarapid activating current IKur. Here the authors provide a general overview of the mechanistic and structural basis of ion selectivity, gating, and pharmacology of the 3 types of cardiac delayed rectifier potassium ion channels. Most blockers bind to S6 residues that line the central cavity of the channel, whereas activators interact with the channel at 4 symmetric binding sites outside the cavity. Copyright © 2016 Elsevier Inc. All rights reserved.

Coronary endothelial function assessment using self-gated cardiac cine MRI and k-t sparse SENSE.

Science.gov (United States)

Yerly, Jérôme; Ginami, Giulia; Nordio, Giovanna; Coristine, Andrew J; Coppo, Simone; Monney, Pierre; Stuber, Matthias

2016-11-01

Electrocardiogram (ECG)-gated cine MRI, paired with isometric handgrip exercise, can be used to accurately, reproducibly, and noninvasively measure coronary endothelial function (CEF). Obtaining a reliable ECG signal at higher field strengths, however, can be challenging due to rapid gradient switching and an increased heart rate under stress. To address these limitations, we present a self-gated cardiac cine MRI framework for CEF measurements that operates without ECG signal. Cross-sectional slices of the right coronary artery (RCA) were acquired using a two-dimensional golden angle radial trajectory. This sampling approach, combined with the k-t sparse SENSE algorithm, allows for the reconstruction of both real-time images for self-gating signal calculations and retrospectively reordered self-gated cine images. CEF measurements were quantitatively compared using both the self-gated and the standard ECG-gated approach. Self-gated cine images with high-quality, temporal, and spatial resolution were reconstructed for 18 healthy volunteers. CEF as measured in self-gated images was in good agreement (R 2  = 0.60) with that measured by its standard ECG-gated counterpart. High spatial and temporal resolution cross-sectional cine images of the RCA can be obtained without ECG signal. The coronary vasomotor response to handgrip exercise compares favorably with that obtained with the standard ECG-gated method. Magn Reson Med 76:1443-1454, 2015. © 2015 International Society for Magnetic Resonance in Medicine. © 2015 International Society for Magnetic Resonance in Medicine.

Multiple Independent Gate FETs: How Many Gates Do We Need?

OpenAIRE

Amarù, Luca; Hills, Gage; Gaillardon, Pierre-Emmanuel; Mitra, Subhasish; De Micheli, Giovanni

2015-01-01

Multiple Independent Gate Field Effect Transistors (MIGFETs) are expected to push FET technology further into the semiconductor roadmap. In a MIGFET, supplementary gates either provide (i) enhanced conduction properties or (ii) more intelligent switching functions. In general, each additional gate also introduces a side implementation cost. To enable more efficient digital systems, MIGFETs must leverage their expressive power to realize complex logic circuits with few physical resources. Rese...

Transparently wrap-gated semiconductor nanowire arrays for studies of gate-controlled photoluminescence

Energy Technology Data Exchange (ETDEWEB)

Nylund, Gustav; Storm, Kristian; Torstensson, Henrik; Wallentin, Jesper; Borgström, Magnus T.; Hessman, Dan; Samuelson, Lars [Solid State Physics, Nanometer Structure Consortium, Lund University, Box 118, S-221 00 Lund (Sweden)

2013-12-04

We present a technique to measure gate-controlled photoluminescence (PL) on arrays of semiconductor nanowire (NW) capacitors using a transparent film of Indium-Tin-Oxide (ITO) wrapping around the nanowires as the gate electrode. By tuning the wrap-gate voltage, it is possible to increase the PL peak intensity of an array of undoped InP NWs by more than an order of magnitude. The fine structure of the PL spectrum reveals three subpeaks whose relative peak intensities change with gate voltage. We interpret this as gate-controlled state-filling of luminescing quantum dot segments formed by zincblende stacking faults in the mainly wurtzite NW crystal structure.

Dual-Gate p-GaN Gate High Electron Mobility Transistors for Steep Subthreshold Slope.

Science.gov (United States)

Bae, Jong-Ho; Lee, Jong-Ho

2016-05-01

A steep subthreshold slope characteristic is achieved through p-GaN gate HEMT with dual-gate structure. Obtained subthreshold slope is less than 120 μV/dec. Based on the measured and simulated data obtained from single-gate device, breakdown of parasitic floating-base bipolar transistor and floating gate charged with holes are responsible to increase abruptly in drain current. In the dual-gate device, on-current degrades with high temperature but subthreshold slope is not changed. To observe the switching speed of dual-gate device and transient response of drain current are measured. According to the transient responses of drain current, switching speed of the dual-gate device is about 10(-5) sec.

Differential distribution of glutamate- and GABA-gated chloride channels in the housefly Musca domestica.

Science.gov (United States)

Kita, Tomo; Ozoe, Fumiyo; Azuma, Masaaki; Ozoe, Yoshihisa

2013-09-01

l-Glutamic acid (glutamate) mediates fast inhibitory neurotransmission by affecting glutamate-gated chloride channels (GluCls) in invertebrates. The molecular function and pharmacological properties of GluCls have been well studied, but not much is known about their physiological role and localization in the insect body. The distribution of GluCls in the housefly (Musca domestica L.) was thus compared with the distribution of γ-aminobutyric acid (GABA)-gated chloride channels (GABACls). Quantitative PCR and ligand-binding experiments indicate that the GluCl and GABACl transcripts and proteins are predominantly expressed in the adult head. Intense GluCl immunostaining was detected in the lamina, leg motor neurons, and legs of adult houseflies. The GABACl (Rdl) immunostaining was more widely distributed, and was found in the medulla, lobula, lobula plate, mushroom body, antennal lobe, and ellipsoid body. The present findings suggest that GluCls have physiological roles in different tissues than GABACls. Copyright © 2013 Elsevier Ltd. All rights reserved.

Top-gate pentacene-based organic field-effect transistor with amorphous rubrene gate insulator

Science.gov (United States)

Hiroki, Mizuha; Maeda, Yasutaka; Ohmi, Shun-ichiro

2018-02-01

The scaling of organic field-effect transistors (OFETs) is necessary for high-density integration and for this, OFETs with a top-gate configuration are required. There have been several reports of damageless lithography processes for organic semiconductor or insulator layers. However, it is still difficult to fabricate scaled OFETs with a top-gate configuration. In this study, the lift-off process and the device characteristics of the OFETs with a top-gate configuration utilizing an amorphous (α) rubrene gate insulator were investigated. We have confirmed that α-rubrene shows an insulating property, and its extracted linear mobility was 2.5 × 10-2 cm2/(V·s). The gate length and width were 10 and 60 µm, respectively. From these results, the OFET with a top-gate configuration utilizing an α-rubrene gate insulator is promising for the high-density integration of scaled OFETs.

Analytical drain current formulation for gate dielectric engineered dual material gate-gate all around-tunneling field effect transistor

Science.gov (United States)

Madan, Jaya; Gupta, R. S.; Chaujar, Rishu

2015-09-01

In this work, an analytical drain current model for gate dielectric engineered (hetero dielectric)-dual material gate-gate all around tunnel field effect transistor (HD-DMG-GAA-TFET) has been developed. Parabolic approximation has been used to solve the two-dimensional (2D) Poisson equation with appropriate boundary conditions and continuity equations to evaluate analytical expressions for surface potential, electric field, tunneling barrier width and drain current. Further, the analog performance of the device is studied for three high-k dielectrics (Si3N4, HfO2, and ZrO2), and it has been investigated that the problem of lower ION, can be overcome by using the hetero-gate architecture. Moreover, the impact of scaling the gate oxide thickness and bias variations has also been studied. The HD-DMG-GAA-TFET shows an enhanced ION of the order of 10-4 A. The effectiveness of the proposed model is validated by comparing it with ATLAS device simulations.

Respiratory gating in positron emission tomography: A quantitative comparison of different gating schemes

International Nuclear Information System (INIS)

Dawood, Mohammad; Buether, Florian; Lang, Norbert; Schober, Otmar; Schaefers, Klaus P

2007-01-01

Respiratory gating is used for reducing the effects of breathing motion in a wide range of applications from radiotherapy treatment to diagnostical imaging. Different methods are feasible for respiratory gating. In this study seven gating methods were developed and tested on positron emission tomography (PET) listmode data. The results of seven patient studies were compared quantitatively with respect to motion and noise. (1) Equal and (2) variable time-based gating methods use only the time information of the breathing cycle to define respiratory gates. (3) Equal and (4) variable amplitude-based gating approaches utilize the amplitude of the respiratory signal. (5) Cycle-based amplitude gating is a combination of time and amplitude-based techniques. A baseline correction was applied to methods (3) and (4) resulting in two new approaches: Baseline corrected (6) equal and (7) variable amplitude-based gating. Listmode PET data from seven patients were acquired together with a respiratory signal. Images were reconstructed applying the seven gating methods. Two parameters were used to quantify the results: Motion was measured as the displacement of the heart due to respiration and noise was defined as the standard deviation of pixel intensities in a background region. The amplitude-based approaches (3) and (4) were superior to the time-based methods (1) and (2). The improvement in capturing the motion was more than 30% (up to 130%) in all subjects. The variable time (2) and amplitude (4) methods had a more uniform noise distribution among all respiratory gates compared to equal time (1) and amplitude (3) methods. Baseline correction did not improve the results. Out of seven different respiratory gating approaches, the variable amplitude method (4) captures the respiratory motion best while keeping a constant noise level among all respiratory phases

Navigator-gated 3D blood oxygen level-dependent CMR at 3.0-T for detection of stress-induced myocardial ischemic reactions.

Science.gov (United States)

Jahnke, Cosima; Gebker, Rolf; Manka, Robert; Schnackenburg, Bernhard; Fleck, Eckart; Paetsch, Ingo

2010-04-01

This study determined the value of navigator-gated 3-dimensional blood oxygen level-dependent (BOLD) cardiac magnetic resonance (CMR) at 3.0-T for the detection of stress-induced myocardial ischemic reactions. Although BOLD CMR has been introduced for characterization of myocardial oxygenation status, previously reported CMR approaches suffered from a low signal-to-noise ratio and motion-related artifacts with impaired image quality and a limited diagnostic value in initial patient studies. Fifty patients with suspected or known coronary artery disease underwent CMR at 3.0-T followed by invasive X-ray angiography within 48 h. Three-dimensional BOLD images were acquired during free breathing with full coverage of the left ventricle in a short-axis orientation. The BOLD imaging was performed at rest and under adenosine stress, followed by stress and rest first-pass perfusion and delayed enhancement imaging. Quantitative coronary X-ray angiography (QCA) was used for coronary stenosis definition (diameter reduction > or =50%). The BOLD and first-pass perfusion images were semiquantitatively evaluated (for BOLD imaging, signal intensity differences between stress and rest [DeltaSI]; for perfusion imaging, myocardial perfusion reserve index [MPRI]). The image quality of BOLD CMR at rest and during adenosine stress was considered good to excellent in 90% and 84% of the patients, respectively. The DeltaSI measurements differed significantly between normal myocardium, myocardium supplied by a stenotic coronary artery, and infarcted myocardium (p exogenous contrast-enhancement studies. Copyright 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

A gate drive circuit for gate-turn-off (GTO) devices in series stack

International Nuclear Information System (INIS)

Despe, O.

1999-01-01

A gate-turn-off (GTO) switch is under development at the Advanced Photon Source as a replacement for a thyratron switch in high power pulsed application. The high voltage in the application requires multiple GTOs connected in series. One component that is critical to the success of GTO operation is the gate drive circuit. The gate drive circuit has to provide fast high-current pulses to the GTO gate for fast turn-on and turn-off. It also has to be able to operate while floating at high voltage. This paper describes a gate drive circuit that meets these requirements

Low-power DRAM-compatible Replacement Gate High-k/Metal Gate Stacks

Science.gov (United States)

Ritzenthaler, R.; Schram, T.; Bury, E.; Spessot, A.; Caillat, C.; Srividya, V.; Sebaai, F.; Mitard, J.; Ragnarsson, L.-Å.; Groeseneken, G.; Horiguchi, N.; Fazan, P.; Thean, A.

2013-06-01

In this work, the possibility of integration of High-k/Metal Gate (HKMG), Replacement Metal Gate (RMG) gate stacks for low power DRAM compatible transistors is studied. First, it is shown that RMG gate stacks used for Logic applications need to be seriously reconsidered, because of the additional anneal(s) needed in a DRAM process. New solutions are therefore developed. A PMOS stack HfO2/TiN with TiN deposited in three times combined with Work Function metal oxidations is demonstrated, featuring a very good Work Function of 4.95 eV. On the other hand, the NMOS side is shown to be a thornier problem to solve: a new solution based on the use of oxidized Ta as a diffusion barrier is proposed, and a HfO2/TiN/TaOX/TiAl/TiN/TiN gate stack featuring an aggressive Work Function of 4.35 eV (allowing a Work Function separation of 600 mV between NMOS and PMOS) is demonstrated. This work paves the way toward the integration of gate-last options for DRAM periphery transistors.

Production of Superoxide in Bacteria Is Stress- and Cell State-Dependent: A Gating-Optimized Flow Cytometry Method that Minimizes ROS Measurement Artifacts with Fluorescent Dyes.

Science.gov (United States)

McBee, Megan E; Chionh, Yok H; Sharaf, Mariam L; Ho, Peiying; Cai, Maggie W L; Dedon, Peter C

2017-01-01

The role of reactive oxygen species (ROS) in microbial metabolism and stress response has emerged as a major theme in microbiology and infectious disease. Reactive fluorescent dyes have the potential to advance the study of ROS in the complex intracellular environment, especially for high-content and high-throughput analyses. However, current dye-based approaches to measuring intracellular ROS have the potential for significant artifacts. Here, we describe a robust platform for flow cytometric quantification of ROS in bacteria using fluorescent dyes, with ROS measurements in 10s-of-1000s of individual cells under a variety of conditions. False positives and variability among sample types (e.g., bacterial species, stress conditions) are reduced with a flexible four-step gating scheme that accounts for side- and forward-scattered light (morphological changes), background fluorescence, DNA content, and dye uptake to identify cells producing ROS. Using CellROX Green dye with Escherichia coli, Mycobacterium smegmatis , and Mycobacterium bovis BCG as diverse model bacteria, we show that (1) the generation of a quantifiable CellROX Green signal for superoxide, but not hydrogen peroxide-induced hydroxyl radicals, validates this dye as a superoxide detector; (2) the level of dye-detectable superoxide does not correlate with cytotoxicity or antibiotic sensitivity; (3) the non-replicating, antibiotic tolerant state of nutrient-deprived mycobacteria is associated with high levels of superoxide; and (4) antibiotic-induced production of superoxide is idiosyncratic with regard to both the species and the physiological state of the bacteria. We also show that the gating method is applicable to other fluorescent indicator dyes, such as the 5-carboxyfluorescein diacetate acetoxymethyl ester and 5-cyano-2,3-ditolyl tetrazolium chloride for cellular esterase and reductive respiratory activities, respectively. These results demonstrate that properly controlled flow cytometry coupled

Oxidative stress protection by newly synthesized nitrogen compounds with pharmacological potential.

Science.gov (United States)

Silva, João P; Areias, Filipe M; Proença, Fernanda M; Coutinho, Olga P

2006-02-09

In this study we used new nitrogen compounds obtained by organic synthesis whose structure predicted an antioxidant potential and then an eventual development as molecules of pharmacological interest in diseases involving oxidative stress. The compounds, identified as FMA4, FMA5, FMA7 and FMA8 differ in the presence of hydroxyl groups located in the C-3 and/or C-4 position of a phenolic unit, which is possibly responsible for their free radicals' buffering capacity. Data from the DPPH discoloration method confirm the high antiradical efficiency of the compounds. The results obtained with cellular models (L929 and PC12) show that they are not toxic and really protect from membrane lipid peroxidation induced by the ascorbate-iron oxidant pair. The level of protection correlates with the drug's lipophilic profile and is sometimes superior to trolox and equivalent to that observed for alpha-tocopherol. The compounds FMA4 and FMA7 present also a high protection from cell death evaluated in the presence of a staurosporine apoptotic stimulus. That protection results in a significant reduction of caspase-3 activity induced by staurosporine which by its turn seems to result from a protection observed in the membrane receptor pathway (caspase-8) together with a protection observed in the mitochondrial pathway (caspase-9). Taken together the results obtained with the new compounds, with linear chains, open up perspectives for their use as therapeutical agents, namely as antioxidants and protectors of apoptotic pathways. On the other hand the slight pro-oxidant profile obtained with the cyclic structures suggests a different therapeutic potential that is under current investigation.

Combined genetic and pharmacological inhibition of TRPV1 and P2X3 attenuates colorectal hypersensitivity and afferent sensitization

OpenAIRE

Kiyatkin, Michael E.; Feng, Bin; Schwartz, Erica S.; Gebhart, G. F.

2013-01-01

The ligand-gated channels transient receptor potential vanilloid 1 (TRPV1) and P2X3 have been reported to facilitate colorectal afferent neuron sensitization, thus contributing to organ hypersensitivity and pain. In the present study, we hypothesized that TRPV1 and P2X3 cooperate to modulate colorectal nociception and afferent sensitivity. To test this hypothesis, we employed TRPV1-P2X3 double knockout (TPDKO) mice and channel-selective pharmacological antagonists and evaluated combined chann...

Transparent field-effect transistors based on AlN-gate dielectric and IGZO-channel semiconductor

International Nuclear Information System (INIS)

Besleaga, C.; Stan, G.E.; Pintilie, I.; Barquinha, P.; Fortunato, E.; Martins, R.

2016-01-01

Highlights: • TFTs based on IGZO channel semiconductor and AlN gate dielectric were fabricated. • AlN films – a viable and cheap gate dielectric alternative for transparent TFTs. • Influence of gate dielectric layer thickness on TFTs electrical characteristics. • No degradation of AlN gate dielectric was observed during devices stress testing. - Abstract: The degradation of thin-film transistors (TFTs) caused by the self-heating effect constitutes a problem to be solved for the next generation of displays. Aluminum nitride (AlN) is a viable alternative for gate dielectric of TFTs due to its good thermal conductivity, matching coefficient of thermal expansion to indium–gallium–zinc-oxide, and excellent stability at high temperatures. Here, AlN thin films of different thicknesses were fabricated by a low temperature reactive radio-frequency magnetron sputtering process, using a low cost, metallic Al target. Their electrical properties have been thoroughly assessed. Furthermore, the 200 nm and 500 nm thick AlN layers have been integrated as gate-dielectric in transparent TFTs with indium–gallium–zinc-oxide as channel semiconductor. Our study emphasizes the potential of AlN thin films for transparent electronics, whilst the functionality of the fabricated field-effect transistors is explored and discussed.

Transparent field-effect transistors based on AlN-gate dielectric and IGZO-channel semiconductor

Energy Technology Data Exchange (ETDEWEB)

Besleaga, C.; Stan, G.E.; Pintilie, I. [National Institute of Materials Physics, 405A Atomistilor, 077125 Magurele-Ilfov (Romania); Barquinha, P.; Fortunato, E. [CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, and CEMOP-UNINOVA, 2829-516 Caparica (Portugal); Martins, R., E-mail: rm@uninova.pt [CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, and CEMOP-UNINOVA, 2829-516 Caparica (Portugal)

2016-08-30

Highlights: • TFTs based on IGZO channel semiconductor and AlN gate dielectric were fabricated. • AlN films – a viable and cheap gate dielectric alternative for transparent TFTs. • Influence of gate dielectric layer thickness on TFTs electrical characteristics. • No degradation of AlN gate dielectric was observed during devices stress testing. - Abstract: The degradation of thin-film transistors (TFTs) caused by the self-heating effect constitutes a problem to be solved for the next generation of displays. Aluminum nitride (AlN) is a viable alternative for gate dielectric of TFTs due to its good thermal conductivity, matching coefficient of thermal expansion to indium–gallium–zinc-oxide, and excellent stability at high temperatures. Here, AlN thin films of different thicknesses were fabricated by a low temperature reactive radio-frequency magnetron sputtering process, using a low cost, metallic Al target. Their electrical properties have been thoroughly assessed. Furthermore, the 200 nm and 500 nm thick AlN layers have been integrated as gate-dielectric in transparent TFTs with indium–gallium–zinc-oxide as channel semiconductor. Our study emphasizes the potential of AlN thin films for transparent electronics, whilst the functionality of the fabricated field-effect transistors is explored and discussed.

Off-state stress and pulse response investigation of InAl/Ga HFET

International Nuclear Information System (INIS)

Florovic, M.; Hronec, P.; Kovac, J.; Skriniarova, J.; Donoval, D.; Kordos, P.

2011-01-01

In this study In 0.18 Al 0.82 N/GaN HFETs were off-state tested under high drain bias, I-V characteristics were measured using standard DC voltage source (drain-source, gate-source). Subsequently drain current responses on pulse gate-source voltage for various drain-source voltages were recorded and analysed. Static performance of InAlN/GaN HFETs with AlN buffer layer prepared at different conditions were analysed before, during and after the off-state stress. The static output I-V characteristics show the maximum drain current I d ≅ 0,44 A/mm for V gs = 6 V, the device has pinch-off at V gs - 4.4 V. The drain and gate currents of the InAlN/GaN HFET were measured continuously during the off-state stress (V ds = 30 V, V gs = -4.4 V), a partial increase of the drain/gate current was observed after this interruption, which indicates on some recovery effect. The devices were characterised in details after the total stress time of 60 min., as well as after 30 min without the stress, the output I-V characteristic show permanent off-state stress degradation. This effect will be studied in details in the next. (authors)

Stress og insomni

DEFF Research Database (Denmark)

Jennum, Poul; Zachariae, Bobby

2012-01-01

Insomnia and stress are two conditions, which are strongly associated and appear to be pathophysiologically integrated: the occurrence of stress increases the risk of insomnia, insomnia exacerbates stress, and coexistence of both factors has a negative influence on their prognosis. Stress...... and insomnia thus share complex interactions and the mechanisms involved are insufficiently understood but involve both psychological and physiological processes. First choice interventions involve behavioural and cognitive strategies and, to a lesser extent, pharmacological treatment....

Gambierol, a toxin produced by the dinoflagellate Gambierdiscus toxicus, is a potent blocker of voltage-gated potassium channels☆

Science.gov (United States)

Cuypers, Eva; Abdel-Mottaleb, Yousra; Kopljar, Ivan; Rainier, Jon D.; Raes, Adam L.; Snyders, Dirk J.; Tytgat, Jan

2008-01-01

In this study, we pharmacologically characterized gambierol, a marine polycyclic ether toxin which is produced by the dinoflagellate Gambierdiscus toxicus. Besides several other polycyclic ether toxins like ciguatoxins, this scarcely studied toxin is one of the compounds that may be responsible for ciguatera fish poisoning (CFP). Unfortunately, the biological target(s) that underlies CFP is still partly unknown. Today, ciguatoxins are described to specifically activate voltage-gated sodium channels by interacting with their receptor site 5. But some dispute about the role of gambierol in the CFP story shows up: some describe voltage-gated sodium channels as the target, while others pinpoint voltage-gated potassium channels as targets. Since gambierol was never tested on isolated ion channels before, it was subjected in this work to extensive screening on a panel of 17 ion channels: nine cloned voltage-gated ion channels (mammalian Nav1.1–Nav1.8 and insect Para) and eight cloned voltage-gated potassium channels (mammalian Kv1.1–Kv1.6, hERG and insect ShakerIR) expressed in Xenopus laevis oocytes using two-electrode voltage-clamp technique. All tested sodium channel subtypes are insensitive to gambierol concentrations up to 10 μM. In contrast, Kv1.2 is the most sensitive voltage-gated potassium channel subtype with almost full block (>97%) and an half maximal inhibitory concentration (IC50) of 34.5 nM. To the best of our knowledge, this is the first study where the selectivity of gambierol is tested on isolated voltage-gated ion channels. Therefore, these results lead to a better understanding of gambierol and its possible role in CFP and they may also be useful in the development of more effective treatments. PMID:18313714

Pharmacological Targeting Of Neuronal Kv7.2/3 Channels: A Focus On Chemotypes And Receptor Sites.

Science.gov (United States)

Miceli, Francesco; Soldovieri, Maria Virginia; Ambrosino, Paolo; Manocchio, Laura; Medoro, Alessandro; Mosca, Ilaria; Taglialatela, Maurizio

2017-10-12

The Kv7 (KCNQ) subfamily of voltage-gated potassium channels consists of 5 members (Kv7.1-5) each showing a characteristic tissue distribution and physiological roles. Given their functional heterogeneity, Kv7 channels represent important pharmacological targets for development of new drugs for neuronal, cardiac and metabolic diseases. In the present manuscript, we focus on describing the pharmacological relevance and the potential therapeutic applications of drugs acting on neuronally-expressed Kv7.2/3 channels, placing particular emphasis on the different modulator chemotypes, and highlighting their pharmacodynamic and, whenever possible, pharmacokinetic peculiarities. The present work is based on an in-depth search of the currently available scientific literature, and on our own experience and knowledge in the field of neuronal Kv7 channel pharmacology. Space limitations impeded to describe the full pharmacological potential of Kv7 channels; thus, we have chosen to focus on neuronal channels composed of Kv7.2 and Kv7.3 subunits, and to mainly concentrate on their involvement in epilepsy. An astonishing heterogeneity in the molecular scaffolds exploitable to develop Kv7.2/3 modulators is evident, with important structural/functional peculiarities of distinct compound classes. In the present work we have attempted to show the current status and growing potential of the Kv7 pharmacology field. We anticipate a bright future for the field, and we express our hopes that the efforts herein reviewed will result in an improved treatment of hyperexcitability (or any other) diseases. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Bias stress effect and recovery in organic field effect transistors : proton migration mechanism

NARCIS (Netherlands)

Sharma, A.; Mathijssen, S.G.J.; Kemerink, M.; Leeuw, de D.M.; Bobbert, P.A.; Bao, Z.; McCulloch, I.

2010-01-01

Organic field-effect transistors exhibit operational instabilities when a gate bias is applied. For a constant gate bias the threshold voltage shifts towards the applied gate bias voltage, an effect known as the bias-stress effect. We have performed a detailed experimental and theoretical study of

Influence of adjuvant detached mindfulness and stress management training compared to pharmacologic treatment in primiparae with postpartum depression.

Science.gov (United States)

Ahmadpanah, Mohammad; Nazaribadie, Marzieh; Aghaei, Elham; Ghaleiha, Ali; Bakhtiari, Azade; Haghighi, Mohammad; Bahmani, Dena Sadeghi; Akhondi, Amineh; Bajoghli, Hafez; Jahangard, Leila; Holsboer-Trachsler, Edith; Brand, Serge

2018-02-01

Ten to 15% of mothers experience postpartum depression (PPD). If untreated, PPD may negatively affect mothers' and infants' mental health in the long term. Accordingly, effective treatments are required. In the present study, we investigated the effect of detached mindfulness (DM) and stress management training (SMT) as adjuvants, compared to pharmacologic treatment only, on symptoms of depression in women with PPD. Forty-five primiparae (mean age: M = 24.5 years) with diagnosed PPD and treated with an SSRI (citalopram; CIT) took part in the study. At baseline, they completed questionnaires covering socio-demographic data and symptoms of depression. Experts rated also symptoms of depression. Next, participants were randomly assigned to one of the following study conditions: adjuvant detached mindfulness (CIT+DM); adjuvant stress management training (CIT+SMT); control condition (CIT). Self- and experts' ratings were completed at the end of the study 8 weeks later, and again at 8 weeks follow-up. Symptoms of depression decreased significantly over time, but more so in the CIT+DM and CIT+SMT group, compared to the control condition. The pattern of results remained stable at follow-up. In primiparae with PPD and treated with a standard SSRI, adjuvant psychotherapeutic interventions led to significant and longer-lasting improvements.

β1 subunit stabilises sodium channel Nav1.7 against mechanical stress.

Science.gov (United States)

Körner, Jannis; Meents, Jannis; Machtens, Jan-Philipp; Lampert, Angelika

2018-06-01

The voltage-gated sodium channel Nav1.7 is a key player in neuronal excitability and pain signalling. In addition to voltage sensing, the channel is also modulated by mechanical stress. Using whole-cell patch-clamp experiments, we discovered that the sodium channel subunit β1 is able to prevent the impact of mechanical stress on Nav1.7. An intramolecular disulfide bond of β1 was identified to be essential for stabilisation of inactivation, but not activation, against mechanical stress using molecular dynamics simulations, homology modelling and site-directed mutagenesis. Our results highlight the role of segment 6 of domain IV in fast inactivation. We present a candidate mechanism for sodium channel stabilisation against mechanical stress, ensuring reliable channel functionality in living systems. Voltage-gated sodium channels are key players in neuronal excitability and pain signalling. Precise gating of these channels is crucial as even small functional alterations can lead to pathological phenotypes such as pain or heart failure. Mechanical stress has been shown to affect sodium channel activation and inactivation. This suggests that stabilising components are necessary to ensure precise channel gating in living organisms. Here, we show that mechanical shear stress affects voltage dependence of activation and fast inactivation of the Nav1.7 channel. Co-expression of the β1 subunit, however, protects both gating modes of Nav1.7 against mechanical shear stress. Using molecular dynamics simulation, homology modelling and site-directed mutagenesis, we identify an intramolecular disulfide bond of β1 (Cys21-Cys43) which is partially involved in this process: the β1-C43A mutant prevents mechanical modulation of voltage dependence of activation, but not of fast inactivation. Our data emphasise the unique role of segment 6 of domain IV for sodium channel fast inactivation and confirm previous reports that the intracellular process of fast inactivation can be

Stress-induced leakage current characteristics of PMOS fabricated by a new multi-deposition multi-annealing technique with full gate last process

International Nuclear Information System (INIS)

Wang Yanrong; Yang Hong; Xu Hao; Luo Weichun; Qi Luwei; Zhang Shuxiang; Wang Wenwu; Zhu Huilong; Zhao Chao; Chen Dapeng; Ye Tianchun; Yan Jiang

2017-01-01

In the process of high- k films fabrication, a novel multi deposition multi annealing (MDMA) technique is introduced to replace simple post deposition annealing. The leakage current decreases with the increase of the post deposition annealing (PDA) times. The equivalent oxide thickness (EOT) decreases when the annealing time(s) change from 1 to 2. Furthermore, the characteristics of SILC (stress-induced leakage current) for an ultra-thin SiO 2 /HfO 2 gate dielectric stack are studied systematically. The increase of the PDA time(s) from 1 to 2 can decrease the defect and defect generation rate in the HK layer. However, increasing the PDA times to 4 and 7 may introduce too much oxygen, therefore the type of oxygen vacancy changes. (paper)

'Motion frozen' quantification and display of myocardial perfusion gated SPECT

International Nuclear Information System (INIS)

Slomka, P.J.; Hurwitz, G.A.; Baddredine, M.; Baranowski, J.; Aladl, U.E.

2002-01-01

Aim: Gated SPECT imaging incorporates both functional and perfusion information of the left ventricle (LV). However perfusion data is confounded by the effect of ventricular motion. Most existing quantification paradigms simply add all gated frames and then proceed to extract the perfusion information from static images, discarding the effects of cardiac motion. In an attempt to improve the reliability and accuracy of cardiac SPECT quantification we propose to eliminate the LV motion prior to the perfusion quantification via automated image warping algorithm. Methods: A pilot series of 14 male and 11 female gated stress SPECT images acquired with 8 time bins have been co-registered to the coordinates of the 3D normal templates. Subsequently the LV endo and epi-cardial 3D points (300-500) were identified on end-systolic (ES) and end-diastolic (ED) frames, defining the ES-ED motion vectors. The nonlinear image warping algorithm (thin-plate-spline) was then applied to warp end-systolic frame was onto the end-diastolic frames using the corresponding ES-ED motion vectors. The remaining 6 intermediate frames were also transformed to the ED coordinates using fractions of the motion vectors. Such warped images were then summed to provide the LV perfusion image in the ED phase but with counts from the full cycle. Results: The identification of the ED/ES corresponding points was successful in all cases. The corrected displacement between ED and ES images was up to 25 mm. The summed images had the appearance of the ED frames but have been much less noisy since all the counts have been used. The spatial resolution of such images appeared higher than that of summed gated images, especially in the female scans. These 'motion frozen' images could be displayed and quantified as regular non-gated tomograms including polar map paradigm. Conclusions: This image processing technique may improve the effective image resolution of summed gated myocardial perfusion images used for

Interpreting anomalies observed in oxide semiconductor TFTs under negative and positive bias stress

Directory of Open Access Journals (Sweden)

Jong Woo Jin

2016-08-01

Full Text Available Oxide semiconductor thin-film transistors can show anomalous behavior under bias stress. Two types of anomalies are discussed in this paper. The first is the shift in threshold voltage (VTH in a direction opposite to the applied bias stress, and highly dependent on gate dielectric material. We attribute this to charge trapping/detrapping and charge migration within the gate dielectric. We emphasize the fundamental difference between trapping/detrapping events occurring at the semiconductor/dielectric interface and those occurring at gate/dielectric interface, and show that charge migration is essential to explain the first anomaly. We model charge migration in terms of the non-instantaneous polarization density. The second type of anomaly is negative VTH shift under high positive bias stress, with logarithmic evolution in time. This can be argued as electron-donating reactions involving H2O molecules or derived species, with a reaction rate exponentially accelerated by positive gate bias and exponentially decreased by the number of reactions already occurred.

Interpreting anomalies observed in oxide semiconductor TFTs under negative and positive bias stress

Energy Technology Data Exchange (ETDEWEB)

Jin, Jong Woo [LPICM, CNRS, Ecole Polytechnique, Université Paris Saclay, 91128, Palaiseau (France); Nathan, Arokia, E-mail: an299@cam.ac.uk [Engineering Department, University of Cambridge, Cambridge, CB3 0FA (United Kingdom); Barquinha, Pedro; Pereira, Luís; Fortunato, Elvira; Martins, Rodrigo [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa and CEMOP/UNINOVA, Campus de Caparica, 2829-516 Caparica (Portugal); Cobb, Brian [Holst Centre/TNO, Eindhoven, 5656 AE (Netherlands)

2016-08-15

Oxide semiconductor thin-film transistors can show anomalous behavior under bias stress. Two types of anomalies are discussed in this paper. The first is the shift in threshold voltage (V{sub TH}) in a direction opposite to the applied bias stress, and highly dependent on gate dielectric material. We attribute this to charge trapping/detrapping and charge migration within the gate dielectric. We emphasize the fundamental difference between trapping/detrapping events occurring at the semiconductor/dielectric interface and those occurring at gate/dielectric interface, and show that charge migration is essential to explain the first anomaly. We model charge migration in terms of the non-instantaneous polarization density. The second type of anomaly is negative V{sub TH} shift under high positive bias stress, with logarithmic evolution in time. This can be argued as electron-donating reactions involving H{sub 2}O molecules or derived species, with a reaction rate exponentially accelerated by positive gate bias and exponentially decreased by the number of reactions already occurred.

A perspective on the contribution of animal models to the pharmacological treatment of posttraumatic stress disorder.

Science.gov (United States)

Bertaina-Anglade, Valerie; O'Connor, Susan M; Andriambeloson, Emile

2017-08-01

Posttraumatic stress disorder (PTSD) is a prevalent, chronic, disabling disorder that may develop following exposure to a traumatic event. This review summarizes currently used animal models of PTSD and their potential role in the development of better therapeutics. Heterogeneity is one of the main characteristics of PTSD with the consequence that many pharmacological approaches are used to relieve symptoms of PTSD. To address the translational properties of the animal models, we discuss the types of stressors used, the rodent correlates of human PTSD (DSM-5) symptoms, and the efficacy of approved, recommended and off-label drugs used to treat PTSD in 'PTSD-animals'. Currently available animal models reproduce most PTSD symptoms and are validated by existing therapeutics. However, novel therapeutics are needed for this disorder as not one drug alleviates all symptoms and many have side effects that lead to non-compliance among PTSD patients. The true translational power of animal models of PTSD will only be demonstrated when new therapeutics acting through novel mechanisms become available for clinical practice.

Expert Oracle GoldenGate

CERN Document Server

Prusinski, Ben; Chung, Richard

2011-01-01

Expert Oracle GoldenGate is a hands-on guide to creating and managing complex data replication environments using the latest in database replication technology from Oracle. GoldenGate is the future in replication technology from Oracle, and aims to be best-of-breed. GoldenGate supports homogeneous replication between Oracle databases. It supports heterogeneous replication involving other brands such as Microsoft SQL Server and IBM DB2 Universal Server. GoldenGate is high-speed, bidirectional, highly-parallelized, and makes only a light impact on the performance of databases involved in replica

Prognostic value of gated 201Tl myocardial perfusion SPECT imaging in patients with coronary artery disease

International Nuclear Information System (INIS)

Li Zicheng; Chen Xiaoming; Xu Hao

2006-01-01

Objective: To study the prognostic value of gated 201 Tl myocardial perfusion SPECT imaging in patients with coronary artery disease and assessment of therapy strategy for the individual patient. Methods: Eighty-four patients underwent rest and exercise stress 201 Tl gated myocardial perfusion SPECT imaging and were followed up for (32.92 ± 16.77) months. Images were studied using 17 segments and 1 to 4 scoring. Global summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS=SSS-SRS) were also calculated. Post-stress and rest ejection fraction (EF) were automatically measured. Results: Nine cardiac events occurred (3.90% per year). SSS, SDS, SRS and EF were the independent predictors of cardiac events (P 201 Tl myocardial perfusion SPECT imaging can provide prognostic assessment for the patients with coronary artery disease and guide in selection of therapeutic strategy. Among all of the indices SSS is the best predictors of cardiac events. (authors)

Autophagy mediates pharmacological lifespan extension by spermidine and resveratrol.

Science.gov (United States)

Morselli, Eugenia; Galluzzi, Lorenzo; Kepp, Oliver; Criollo, Alfredo; Maiuri, Maria Chiara; Tavernarakis, Nektarios; Madeo, Frank; Kroemer, Guido

2009-12-23

Although autophagy has widely been conceived as a self-destructive mechanism that causes cell death, accumulating evidence suggests that autophagy usually mediates cytoprotection, thereby avoiding the apoptotic or necrotic demise of stressed cells. Recent evidence produced by our groups demonstrates that autophagy is also involved in pharmacological manipulations that increase longevity. Exogenous supply of the polyamine spermidine can prolong the lifespan of (while inducing autophagy in) yeast, nematodes and flies. Similarly, resveratrol can trigger autophagy in cells from different organisms, extend lifespan in nematodes, and ameliorate the fitness of human cells undergoing metabolic stress. These beneficial effects are lost when essential autophagy modulators are genetically or pharmacologically inactivated, indicating that autophagy is required for the cytoprotective and/or anti-aging effects of spermidine and resveratrol. Genetic and functional studies indicate that spermidine inhibits histone acetylases, while resveratrol activates the histone deacetylase Sirtuin 1 to confer cytoprotection/longevity. Although it remains elusive whether the same histones (or perhaps other nuclear or cytoplasmic proteins) act as the downstream targets of spermidine and resveratrol, these results point to an essential role of protein hypoacetylation in autophagy control and in the regulation of longevity.

Factors affecting accuracy of ventricular volume and ejection fraction measured by gated Tl-201 myocardial perfusion single photon emission computed tomography

International Nuclear Information System (INIS)

Pai, Moon Sun; Yang, You Jung; Im, Ki Chun; Hong, Il Ki; Yun, Sung Cheol; Kang, Duk Hyun; Song, Jae Kwan; Moon, Dae Hyuk

2005-01-01

Systemic errors in the gated single photon emission computed tomography (SPECT) measurement of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) may occur. We evaluated whether patient-related factors affected the accuracy of EDV, ESV, and EF measured by electrocardiogram-gated Tl-201 SPECT. A total of 518 patients without perfusion defects on Tl-201 SPECT or coronary artery disease were studied. EDV, ESV, and EF were measured from echocardiography and adenosine stress/redistribution gated Tl-201 SPECT using commercially available software packages (QGS and 4D-MSPECT). We identified factors affecting the accuracy of gated SPECT via multiple linear regression analysis of the differences between echocardiography and gated SPECT. Gated SPECT analyzed with QGS underestimated EDV and ESV, and overestimated EF, but 4D-MSPECT overestimated all those values (p<0.001). Independent variables that increased the difference in EDV between echocardiography and gated SPECT were decreasing LV end-diastolic wall thickness, decreasing body surface area, female sex and increasing EDV (p< 0.001). Those for ESV were decreasing LV end-systolic wall thickness, female sex, and decreasing ESV (p<0.001). Increasing end-systolic wall thickness, male sex and decreasing age were independent determinants associated with an increased difference in EF (p< 0.001). Adenosine stress SPECT showed significantly higher EDV and ESV values and a lower EF than did redistribution SPECT (p< 0.001). In determination of EF, QGS demonstrated a smaller bias than did 4D-MSPECT. However, in men with LV hypertrophy, 4D-MSPECT was superior to QGS. Systemic error by gated Tl-201 SPECT is determined by individual patient-characteristics

Beyond the drugs : non-pharmacological strategies to optimize procedural care in children

NARCIS (Netherlands)

Leroy, Piet L.; Costa, Luciane R.; Emmanouil, Dimitris; van Beukering, Alice; Franck, Linda S.

2016-01-01

Purpose of review Painful and/or stressful medical procedures mean a substantial burden for sick children. There is good evidence that procedural comfort can be optimized by a comprehensive comfort-directed policy containing the triad of non-pharmacological strategies (NPS) in all cases, timely or

Degradation and lifetime estimation of n-MOS SLS ELA polycrystalline TFTs during hot carrier stressing: effect of channel width in the region Vth ≤ VGS,stress ≤ VDS,stress/2

International Nuclear Information System (INIS)

Kontogiannopoulos, G P; Farmakis, F V; Kouvatsos, D N; Papaioannou, G J; Voutsas, A T

2009-01-01

The voltage bias stress induced degradation of sequential lateral solidification (SLS) polysilicon thin film transistors (TFTs) is studied. The aim of this work is the investigation of the types of damage arising from the electrical stressing in the gate voltage range around V th ≤ V GS,stress ≤ V DS,stress /2 and for different drain-bias voltages. It is shown that the drain on-current variation (%) with stressing time for a defined gate voltage obeys a power–time-dependent law of the form At n . The parameters A and n of this law were determined in order to gain insight on degradation mechanisms in different stress regimes and to estimate the time to failure of our devices. Devices with different channel widths were compared, and their lifetime to failure was extracted. It was found that the magnitude of stress was lower for devices with narrower channel widths. By monitoring the threshold voltage variation and the percentage change of transconductance maximum in the linear regime of operation, it was verified that the threshold voltage degradation was mainly due to the contribution of G m,max to V th rather than severe carrier trapping

GATE V6: a major enhancement of the GATE simulation platform enabling modelling of CT and radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Jan, S; Becheva, E [DSV/I2BM/SHFJ, Commissariat a l' Energie Atomique, Orsay (France); Benoit, D; Rehfeld, N; Stute, S; Buvat, I [IMNC-UMR 8165 CNRS-Paris 7 and Paris 11 Universities, 15 rue Georges Clemenceau, 91406 Orsay Cedex (France); Carlier, T [INSERM U892-Cancer Research Center, University of Nantes, Nantes (France); Cassol, F; Morel, C [Centre de physique des particules de Marseille, CNRS-IN2P3 and Universite de la Mediterranee, Aix-Marseille II, 163, avenue de Luminy, 13288 Marseille Cedex 09 (France); Descourt, P; Visvikis, D [INSERM, U650, Laboratoire du Traitement de l' Information Medicale (LaTIM), CHU Morvan, Brest (France); Frisson, T; Grevillot, L; Guigues, L; Sarrut, D; Zahra, N [Universite de Lyon, CREATIS, CNRS UMR5220, Inserm U630, INSA-Lyon, Universite Lyon 1, Centre Leon Berard (France); Maigne, L; Perrot, Y [Laboratoire de Physique Corpusculaire, 24 Avenue des Landais, 63177 Aubiere Cedex (France); Schaart, D R [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands); Pietrzyk, U, E-mail: buvat@imnc.in2p3.fr [Reseach Center Juelich, Institute of Neurosciences and Medicine and Department of Physics, University of Wuppertal (Germany)

2011-02-21

GATE (Geant4 Application for Emission Tomography) is a Monte Carlo simulation platform developed by the OpenGATE collaboration since 2001 and first publicly released in 2004. Dedicated to the modelling of planar scintigraphy, single photon emission computed tomography (SPECT) and positron emission tomography (PET) acquisitions, this platform is widely used to assist PET and SPECT research. A recent extension of this platform, released by the OpenGATE collaboration as GATE V6, now also enables modelling of x-ray computed tomography and radiation therapy experiments. This paper presents an overview of the main additions and improvements implemented in GATE since the publication of the initial GATE paper (Jan et al 2004 Phys. Med. Biol. 49 4543-61). This includes new models available in GATE to simulate optical and hadronic processes, novelties in modelling tracer, organ or detector motion, new options for speeding up GATE simulations, examples illustrating the use of GATE V6 in radiotherapy applications and CT simulations, and preliminary results regarding the validation of GATE V6 for radiation therapy applications. Upon completion of extensive validation studies, GATE is expected to become a valuable tool for simulations involving both radiotherapy and imaging.

Improvements in the reliability of a-InGaZnO thin-film transistors with triple stacked gate insulator in flexible electronics applications

Energy Technology Data Exchange (ETDEWEB)

Chen, Hua-Mao [Department of Photonics & Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan (China); Chang, Ting-Chang, E-mail: tcchang3708@gmail.com [Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Advanced Optoelectronics Technology Center, National Cheng Kung University, Taiwan (China); Tai, Ya-Hsiang [Department of Photonics & Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan (China); Chen, Kuan-Fu [Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Chiang, Hsiao-Cheng [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Liu, Kuan-Hsien [Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan (China); Lee, Chao-Kuei [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Lin, Wei-Ting; Cheng, Chun-Cheng; Tu, Chun-Hao; Liu, Chu-Yu [Advanced Technology Research Center, AU Optronics Corp, Hsinchu, Taiwan (China)

2015-11-30

This study examined the impact of the low-temperature stacking gate insulator on the gate bias instability of a-InGaZnO thin film transistors in flexible electronics applications. Although the quality of SiN{sub x} at low process/deposition temperature is better than that of SiO{sub x} at similarly low process/deposition temperature, there is still a very large positive threshold voltage (V{sub th}) shift of 9.4 V for devices with a single low-temperature SiN{sub x} gate insulator under positive gate bias stress. However, a suitable oxide–nitride–oxide-stacked gate insulator exhibits a V{sub th} shift of only 0.23 V. This improvement results from the larger band offset and suitable gate insulator thickness that can effectively suppress carrier trapping behavior. - Highlights: • The cause of the bias instability for a low-temperature gate insulator is verified. • A triple-stacked gate insulator was fabricated. • A suitable triple stacked gate insulator shows only 0.23 V threshold voltage shift.

Novel Quantum Dot Gate FETs and Nonvolatile Memories Using Lattice-Matched II-VI Gate Insulators

Science.gov (United States)

Jain, F. C.; Suarez, E.; Gogna, M.; Alamoody, F.; Butkiewicus, D.; Hohner, R.; Liaskas, T.; Karmakar, S.; Chan, P.-Y.; Miller, B.; Chandy, J.; Heller, E.

2009-08-01

This paper presents the successful use of ZnS/ZnMgS and other II-VI layers (lattice-matched or pseudomorphic) as high- k gate dielectrics in the fabrication of quantum dot (QD) gate Si field-effect transistors (FETs) and nonvolatile memory structures. Quantum dot gate FETs and nonvolatile memories have been fabricated in two basic configurations: (1) monodispersed cladded Ge nanocrystals (e.g., GeO x -cladded-Ge quantum dots) site-specifically self-assembled over the lattice-matched ZnMgS gate insulator in the channel region, and (2) ZnTe-ZnMgTe quantum dots formed by self-organization, using metalorganic chemical vapor-phase deposition (MOCVD), on ZnS-ZnMgS gate insulator layers grown epitaxially on Si substrates. Self-assembled GeO x -cladded Ge QD gate FETs, exhibiting three-state behavior, are also described. Preliminary results on InGaAs-on-InP FETs, using ZnMgSeTe/ZnSe gate insulator layers, are presented.

Integration issues of high-k and metal gate into conventional CMOS technology

International Nuclear Information System (INIS)

Song, S.C.; Zhang, Z.; Huffman, C.; Bae, S.H.; Sim, J.H.; Kirsch, P.; Majhi, P.; Moumen, N.; Lee, B.H.

2006-01-01

Issues surrounding the integration of Hf-based high-k dielectrics with metal gates in a conventional CMOS flow are discussed. The careful choice of a gate stack process as well as optimization of other CMOS process steps enables robust CMOSFETs with a wide process latitude. HfO 2 of a 2 nm physical thickness shows complete suppression of transient charge trapping resulting from a significant reduction in film volume as well as kinetically suppressed crystallization. Metal thickness is also critical when optimizing physical stress effects and minimizing dopant diffusion. A high temperature anneal after source and drain implantation in a conventional CMOSFET process reduces the interface state density and improves electron mobility

Temporal and voltage stress stability of high performance indium-zinc-oxide thin film transistors

Science.gov (United States)

Song, Yang; Katsman, Alexander; Butcher, Amy L.; Paine, David C.; Zaslavsky, Alexander

2017-10-01

Thin film transistors (TFTs) based on transparent oxide semiconductors, such as indium zinc oxide (IZO), are of interest due to their improved characteristics compared to traditional a-Si TFTs. Previously, we reported on top-gated IZO TFTs with an in-situ formed HfO2 gate insulator and IZO active channel, showing high performance: on/off ratio of ∼107, threshold voltage VT near zero, extracted low-field mobility μ0 = 95 cm2/V·s, and near-perfect subthreshold slope at 62 mV/decade. Since device stability is essential for technological applications, in this paper we report on the temporal and voltage stress stability of IZO TFTs. Our devices exhibit a small negative VT shift as they age, consistent with an increasing carrier density resulting from an increasing oxygen vacancy concentration in the channel. Under gate bias stress, freshly annealed TFTs show a negative VT shift during negative VG gate bias stress, while aged (>1 week) TFTs show a positive VT shift during negative VG stress. This indicates two competing mechanisms, which we identify as the field-enhanced generation of oxygen vacancies and the field-assisted migration of oxygen vacancies, respectively. A simplified kinetic model of the vacancy concentration evolution in the IZO channel under electrical stress is provided.

Characterization of a vertically movable gate field effect transistor using a silicon-on-insulator wafer

Science.gov (United States)

Song, In-Hyouk; Forfang, William B. D.; Cole, Bryan; You, Byoung Hee

2014-10-01

The vertically movable gate field effect transistor (VMGFET) is a FET-based sensing element, whose gate moves in a vertical direction over the channel. A VMGFET gate covers the region between source and drain. A 1 μm thick air layer separates the gate and the substrate of the VMGFET. A novel fabrication process to form a VMGFET using a silicon-on-insulator (SOI) wafer provides minimal internal stress of the gate structure. The enhancement-type n-channel VMGFET is fabricated with the threshold voltage of 2.32 V in steady state. A non-inverting amplifier is designed and integrated on a printable circuit board (PCB) to characterize device sensitivity and mechanical properties. The VMGFET is mechanically coupled to a speaker membrane to apply mechanical vibration. The oscillated drain current of FET are monitored and sampled with NI LabVIEW. The frequency of the output signal correlates with that of the input stimulus. The resonance frequency of the fabricated VMGFET is measured to be 1.11 kHz. The device sensitivity linearly increases by 0.106 mV/g Hz in the range of 150 Hz and 1 kHz.

Characterization of a vertically movable gate field effect transistor using a silicon-on-insulator wafer

International Nuclear Information System (INIS)

Song, In-Hyouk; Forfang, William B D; Cole, Bryan; Hee You, Byoung

2014-01-01

The vertically movable gate field effect transistor (VMGFET) is a FET-based sensing element, whose gate moves in a vertical direction over the channel. A VMGFET gate covers the region between source and drain. A 1 μm thick air layer separates the gate and the substrate of the VMGFET. A novel fabrication process to form a VMGFET using a silicon-on-insulator (SOI) wafer provides minimal internal stress of the gate structure. The enhancement-type n-channel VMGFET is fabricated with the threshold voltage of 2.32 V in steady state. A non-inverting amplifier is designed and integrated on a printable circuit board (PCB) to characterize device sensitivity and mechanical properties. The VMGFET is mechanically coupled to a speaker membrane to apply mechanical vibration. The oscillated drain current of FET are monitored and sampled with NI LabVIEW. The frequency of the output signal correlates with that of the input stimulus. The resonance frequency of the fabricated VMGFET is measured to be 1.11 kHz. The device sensitivity linearly increases by 0.106 mV/g Hz in the range of 150 Hz and 1 kHz. (paper)

New opening hours of the gates

CERN Multimedia

GS Department

2009-01-01

Please note the new opening hours of the gates as well as the intersites tunnel from the 19 May 2009: GATE A 7h - 19h GATE B 24h/24 GATE C 7h - 9h\t17h - 19h GATE D 8h - 12h\t13h - 16h GATE E 7h - 9h\t17h - 19h Prévessin 24h/24 The intersites tunnel will be opened from 7h30 to 18h non stop. GS-SEM Group Infrastructure and General Services Department

Optical XOR gate

Science.gov (United States)

Vawter, G. Allen

2013-11-12

An optical XOR gate is formed as a photonic integrated circuit (PIC) from two sets of optical waveguide devices on a substrate, with each set of the optical waveguide devices including an electroabsorption modulator electrically connected in series with a waveguide photodetector. The optical XOR gate utilizes two digital optical inputs to generate an XOR function digital optical output. The optical XOR gate can be formed from III-V compound semiconductor layers which are epitaxially deposited on a III-V compound semiconductor substrate, and operates at a wavelength in the range of 0.8-2.0 .mu.m.

Intrinsic respiratory gating in small-animal CT

International Nuclear Information System (INIS)

Bartling, Soenke H.; Dinkel, Julien; Kauczor, Hans-Ulrich; Stiller, Wolfram; Semmler, Wolfhard; Grasruck, Michael; Madisch, Ijad; Gupta, Rajiv; Kiessling, Fabian

2008-01-01

Gating in small-animal CT imaging can compensate artefacts caused by physiological motion during scanning. However, all published gating approaches for small animals rely on additional hardware to derive the gating signals. In contrast, in this study a novel method of intrinsic respiratory gating of rodents was developed and tested for mice (n=5), rats (n=5) and rabbits (n=2) in a flat-panel cone-beam CT system. In a consensus read image quality was compared with that of non-gated and retrospective extrinsically gated scans performed using a pneumatic cushion. In comparison to non-gated images, image quality improved significantly using intrinsic and extrinsic gating. Delineation of diaphragm and lung structure improved in all animals. Image quality of intrinsically gated CT was judged to be equivalent to extrinsically gated ones. Additionally 4D datasets were calculated using both gating methods. Values for expiratory, inspiratory and tidal lung volumes determined with the two gating methods were comparable and correlated well with values known from the literature. We could show that intrinsic respiratory gating in rodents makes additional gating hardware and preparatory efforts superfluous. This method improves image quality and allows derivation of functional data. Therefore it bears the potential to find wide applications in small-animal CT imaging. (orig.)

Paradoxical motion of interventricular septum on Tc-99m MIBI gated SPECT study

International Nuclear Information System (INIS)

Ergun, E.L.; Erbas, B.; Beylergil, V.; Demirturk, O.S.; Pasaoglu, I.

2004-01-01

After uncomplicated cardiac surgery, abnormal motion of the interventricular septum is frequently observed. The interventricular septum has often been found to display dyskinetic, or paradoxical motion by echocardiographic studies. This study was undertaken to describe instances of paradoxical motion of interventricular septum on Tc-99m MIBI gated SPECT studies in patients after coronary artery by pass graft surgery. Tc-99m MIBI gated SPECT in conjunction with stress myocardial perfusion SPECT was performed in 18 patients who had history of cardiac bypass graft surgery. Paradoxical motion of the interventricular septum was defined visually from Tc-99m MIBI gated SPECT. Perfusion of the interventricular septum was examined from myocardial perfusion images in the same study. Paradoxical motion of the interventricular septum was observed in 4 patients (22%). The interventricular septum was normally perfused in all patients. It was concluded that paradoxical motion of the interventricular septum in patients who had a history of cardiac by-pass graft surgery is not an uncommon finding and it can be observed with gated SPECT. The exact mechanism of this phenomenon is not well-known. A normal perfusion in interventricular wall helps to discriminate this situation from a real abnormality. (author)

Fluoroscopy-guided hydrostatic reduction of intussusception in infancy: role of pharmacological premedication.

Science.gov (United States)

Esposito, Francesco; Ambrosio, Concetta; De Fronzo, Simona; Panico, Maria Rita; D'Aprano, Marilena; Giugliano, Anna Marcella; Noviello, Domenico; Oresta, Patrizia

2015-06-01

Intussusception is one of the most common causes of paediatric emergency. Fluoroscopy-guided hydrostatic reduction is a common nonoperative management strategy for the treatment of intussusception. The role of pharmacological premedication in increasing the success rate of hydrostatic reduction is still controversial. The purpose of this study was to verify the presence of a possible correlation between pharmacological premedication and the percentage of hydrostatic reduction of intussusception in paediatric patients. This study considered children with a diagnosis of idiopathic intussusception treated at our hospital between January 2007 and June 2013. One group of patients underwent hydrostatic reduction by barium enema without any preliminary therapy. A second group of patients received pharmacological premedication with both a sedative and an anti-oedematous agent before the procedure. A total of 398 patients were treated with barium enema for therapeutic purposes. In the group of patients who received no premedication (n = 254), 165 (65 %) children achieved hydrostatic reduction of the intussusception. Among the patients who received pharmacological premedication prior to barium enema (n = 144), 122 (85 %) children achieved resolution of the intussusception. Our study shows that the use of pharmacological premedication is effective for the reduction of the intussusception, as its limit patient stress, fluoroscopic time and radiation dose.

Signatures of Mechanosensitive Gating.

Science.gov (United States)

Morris, Richard G

2017-01-10

The question of how mechanically gated membrane channels open and close is notoriously difficult to address, especially if the protein structure is not available. This perspective highlights the relevance of micropipette-aspirated single-particle tracking-used to obtain a channel's diffusion coefficient, D, as a function of applied membrane tension, σ-as an indirect assay for determining functional behavior in mechanosensitive channels. While ensuring that the protein remains integral to the membrane, such methods can be used to identify not only the gating mechanism of a protein, but also associated physical moduli, such as torsional and dilational rigidity, which correspond to the protein's effective shape change. As an example, three distinct D-versus-σ "signatures" are calculated, corresponding to gating by dilation, gating by tilt, and gating by a combination of both dilation and tilt. Both advantages and disadvantages of the approach are discussed. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Quantum gate decomposition algorithms.

Energy Technology Data Exchange (ETDEWEB)

Slepoy, Alexander

2006-07-01

Quantum computing algorithms can be conveniently expressed in a format of a quantum logical circuits. Such circuits consist of sequential coupled operations, termed ''quantum gates'', or quantum analogs of bits called qubits. We review a recently proposed method [1] for constructing general ''quantum gates'' operating on an qubits, as composed of a sequence of generic elementary ''gates''.

Influence of the charge trap density distribution in a gate insulator on the positive-bias stress instability of amorphous indium-gallium-zinc oxide thin-film transistors

Energy Technology Data Exchange (ETDEWEB)

Kim, Eungtaek; Kim, Choong-Ki; Lee, Myung Keun; Bang, Tewook; Choi, Yang-Kyu; Choi, Kyung Cheol, E-mail: shkp@kaist.ac.kr, E-mail: kyungcc@kaist.ac.kr [School of Electrical Engineering, KAIST, Daejeon 34141 (Korea, Republic of); Park, Sang-Hee Ko, E-mail: shkp@kaist.ac.kr, E-mail: kyungcc@kaist.ac.kr [Department of Material Science and Engineering, KAIST, Daejeon 34141 (Korea, Republic of)

2016-05-02

We investigated the positive-bias stress (PBS) instability of thin film transistors (TFTs) composed of different types of first-gate insulators, which serve as a protection layer of the active surface. Two different deposition methods, i.e., the thermal atomic layer deposition (THALD) and plasma-enhanced ALD (PEALD) of Al{sub 2}O{sub 3}, were applied for the deposition of the first GI. When THALD was used to deposit the GI, amorphous indium-gallium-zinc oxide (a-IGZO) TFTs showed superior stability characteristics under PBS. For example, the threshold voltage shift (ΔV{sub th}) was 0 V even after a PBS time (t{sub stress}) of 3000 s under a gate voltage (V{sub G}) condition of 5 V (with an electrical field of 1.25 MV/cm). On the other hand, when the first GI was deposited by PEALD, the ΔV{sub th} value of a-IGZO TFTs was 0.82 V after undergoing an identical amount of PBS. In order to interpret the disparate ΔV{sub th} values resulting from PBS quantitatively, the average oxide charge trap density (N{sub T}) in the GI and its spatial distribution were investigated through low-frequency noise characterizations. A higher N{sub T} resulted during in the PEALD type GI than in the THALD case. Specifically, the PEALD process on a-IGZO layer surface led to an increasing trend of N{sub T} near the GI/a-IGZO interface compared to bulk GI owing to oxygen plasma damage on the a-IGZO surface.

Self-gated fat-suppressed cardiac cine MRI.

Science.gov (United States)

Ingle, R Reeve; Santos, Juan M; Overall, William R; McConnell, Michael V; Hu, Bob S; Nishimura, Dwight G

2015-05-01

To develop a self-gated alternating repetition time balanced steady-state free precession (ATR-SSFP) pulse sequence for fat-suppressed cardiac cine imaging. Cardiac gating is computed retrospectively using acquired magnetic resonance self-gating data, enabling cine imaging without the need for electrocardiogram (ECG) gating. Modification of the slice-select rephasing gradients of an ATR-SSFP sequence enables the acquisition of a one-dimensional self-gating readout during the unused short repetition time (TR). Self-gating readouts are acquired during every TR of segmented, breath-held cardiac scans. A template-matching algorithm is designed to compute cardiac trigger points from the self-gating signals, and these trigger points are used for retrospective cine reconstruction. The proposed approach is compared with ECG-gated ATR-SSFP and balanced steady-state free precession in 10 volunteers and five patients. The difference of ECG and self-gating trigger times has a variability of 13 ± 11 ms (mean ± SD). Qualitative reviewer scoring and ranking indicate no statistically significant differences (P > 0.05) between self-gated and ECG-gated ATR-SSFP images. Quantitative blood-myocardial border sharpness is not significantly different among self-gated ATR-SSFP ( 0.61±0.15 mm -1), ECG-gated ATR-SSFP ( 0.61±0.15 mm -1), or conventional ECG-gated balanced steady-state free precession cine MRI ( 0.59±0.15 mm -1). The proposed self-gated ATR-SSFP sequence enables fat-suppressed cardiac cine imaging at 1.5 T without the need for ECG gating and without decreasing the imaging efficiency of ATR-SSFP. © 2014 Wiley Periodicals, Inc.

Quality management of pharmacology and safety pharmacology studies

DEFF Research Database (Denmark)

Spindler, Per; Seiler, Jürg P

2002-01-01

to safety pharmacology studies, and, when indicated, to secondary pharmacodynamic studies, does not influence the scientific standards of studies. However, applying formal GLP standards will ensure the quality, reliability and integrity of studies, which reflect sound study management. It is important...... to encourage a positive attitude among researchers and academics towards these lines, whenever possible. GLP principles applied to the management of non-clinical safety studies are appropriate quality standards when studies are used in the context of protecting public health, and these quality standards...... of pharmacology studies (ICH S7A): primary pharmacodynamic, secondary pharmacodynamic and safety pharmacology studies, and guidance on the quality standards (expectations for GLP conformity) for these study types have been provided. Primary pharmacodynamic studies are the only study types that are fully exempt...

Low band-to-band tunnelling and gate tunnelling current in novel nanoscale double-gate architecture: simulations and investigation

International Nuclear Information System (INIS)

Datta, Deepanjan; Ganguly, Samiran; Dasgupta, S

2007-01-01

Large band-to-band tunnelling (BTBT) and gate leakage current can limit scalability of nanoscale devices. In this paper, we have proposed a novel nanoscale parallel connected heteromaterial double gate (PCHEM-DG) architecture with triple metal gate which significantly suppress BTBT leakage, making it efficient for low power design in the sub-10 nm regime. We have also proposed a triple gate device with p + poly-n + poly-p + poly gate which has substantially low gate leakage over symmetric DG MOSFET. Simulations are performed using a 2D Poisson-Schroedinger simulator and verified with a 2D device simulator ATLAS. We conclude that, due to intrinsic body doping, negligible gate leakage, suppressed BTBT over symmetric DG devices, metal gate (MG) PCHEM-DG MOSFET is efficient for low power circuit design in the nanometre regime

Visualization of neonatal coronary arteries on multidetector row CT: ECG-gated versus non-ECG-gated technique

International Nuclear Information System (INIS)

Tsai, I.C.; Lee, Tain; Chen, Min-Chi; Fu, Yun-Ching; Jan, Sheng-Lin; Wang, Chung-Chi; Chang, Yen

2007-01-01

Multidetector CT (MDCT) seems to be a promising tool for detection of neonatal coronary arteries, but whether the ECG-gated or non-ECG-gated technique should be used has not been established. To compare the detection rate and image quality of neonatal coronary arteries on MDCT using ECG-gated and non-ECG-gated techniques. Twelve neonates with complex congenital heart disease were included. The CT scan was acquired using an ECG-gated technique, and the most quiescent phase of the RR interval was selected to represent the ECG-gated images. The raw data were then reconstructed without the ECG signal to obtain non-ECG-gated images. The detection rate and image quality of nine coronary artery segments in the two sets of images were then compared. A two-tailed paired t test was used with P values <0.05 considered as statistically significant. In all coronary segments the ECG-gated technique had a better detection rate and produced images of better quality. The difference between the two techniques ranged from 25% in the left main coronary artery to 100% in the distal right coronary artery. For neonates referred for MDCT, if evaluation of coronary artery anatomy is important for the clinical management or surgical planning, the ECG-gated technique should be used because it can reliably detect the coronary arteries. (orig.)

Pharmacological treatment of refugees with trauma-related disorders

DEFF Research Database (Denmark)

Sonne, Charlotte; Carlsson, Jessica; Bech, Per

2017-01-01

traumatic stress disorder (PTSD). We conducted a systematic review of published treatment outcome studies on PTSD and depression among refugees. Fifteen studies were identified and reviewed. Most studies focused on the use of antidepressants. Included studies differed widely in method and quality....... The majority were observational studies and case studies. Small sample sizes limited the statistical power. Few studies reported effect sizes, confidence intervals, and statistical significance of findings. No specific pharmacological treatment for PTSD among refugees can be recommended on the basis...

Effects of perfusion detect on the measurement of left ventricular mass, ventricular volume and post-stress left ventricular ejection fraction in gated myocardial perfusion SPECT

International Nuclear Information System (INIS)

Ahn, Byeong Cheol; Bae, Sun Keun; Lee, Sang Woo; Jeong, Sin Young; Lee, Jae Tae; Lee, Kyu Bo

2002-01-01

The presence of perfusion defect may influence the left ventricular mass (LVM) measurement by quantitative gated myocardial perfusion SPECT (QGS), and ischemic myocardium, usually showing perfusion defect may produce post-stress LV dysfunction. This study was aimed to evaluated the effects of extent and reversibility of perfusion defect on the automatic measurement of LVM by QGS and to investigate the effect of reversibility of perfusion defect on post-stress LV dysfunction. Forty-six patients (male/female=34:12, mean age=64 years) with perfusion defect on myocardial perfusion SPECT underwent rest and post-stress QGS. Forty patients (87%) showed reversible defect. End-diastolic volume (EDV), end-systolic volume (ESV), LV ejection fraction (EF), and LV myocardial volume were obtained from QGS by autoquant program, and LVM was calculated by multiplying the LV myocardial volume by the specific gravity of myocardium. LVMs measured at rest and post-stress QGS showed good correlation, and higher correlation was founded in the subjects with fixed perfusion defect and with small defect (smaller than 20%). There were no significant differences in EDVs, ESVs and EFs between obtained by rest and post-stress QGS in patients with fixed myocardial defect. Whereas, EF obtained by post-stress QGS was lower than that by rest QGS in patients with reversible defect and 10 (25%) of them showed decreases in EF more than 5% in post-stress QGS, as compared to that of rest QGS. Excellent correlations of EDVs, ESVs, EFs between rest and post-stress QGS were noted. Patients with fixed defect had higher correlation between defect can affect LVM measurement by QGS and patients with reversible defect shows post-stress LV dysfunction more frequently than patients with fixed perfusion defect

A comparison of maximal exercise and dipyridamole thallium-201 planar gated scintigraphy

International Nuclear Information System (INIS)

Martin, W.; Tweddel, A.C.; Main, G.; Hutton, I.

1992-01-01

Both symptom-limited maximal exercise and intravenously given dipyridamole stress (0.56 mg/kg over 4 min with a 2 min walk) gated thallium scans were performed in 22 patients undergoing coronary arteriography for the assessment of chest pain. All scans were acquired gated to the electrocardiogram in 3 projections and were reported for the presence and extent of defects in 5 myocardial segments in each view. In addition, left and right ventricular myocardial uptake and estimates of right and left lung and liver to left ventricular uptake were assessed relative to the injected dose of thallium-201. Overall, 190/310 segments were abnormal with exercise compared with 169/310 with dipyridamole. Segments were scored greater in extent in 90/310 cases with exercise, compared with 46/310 in which the defect was more extensive with dipyridamole. Non-attenuation corrected percentage myocardial thallium uptakes were similar for both stresses. Left and right lung and liver to left ventricle ratios were all significantly higher with dipyridamole than with exercise. High right and left lung uptakes with dipyridamole were strongly correlated with high exercise values. The liver uptake was weakly correlated between the 2 different stress tests. These results demonstrate that dipyridamole induces fewer and less extensive thallium perfusion defects than maximal exercise, and that liver and lung to myocardial ratios are higher with dipyridamole than with exercise. (orig./MG)

Delirium in the elderly: A systematic review of pharmacological and non-pharmacological treatments

Directory of Open Access Journals (Sweden)

Cecília Carboni Tardelli Cerveira

Full Text Available ABSTRACT Delirium is a common disorder associated with poor prognosis, especially in the elderly. The impact of different treatment approaches for delirium on morbimortality and long-term welfare is not completely understood. OBJECTIVE: To determine the efficacy of pharmacological and non-pharmacological treatments in elderly patients with delirium. METHODS: This systematic review compared pharmacological and non-pharmacological treatments in patients over 60 years old with delirium. Databases used were: MEDLINE (PubMed, EMBASE, Cochrane CENTRAL and LILACS from inception to January 6th, 2016. RESULTS: A total of ten articles were selected. The six non-pharmacological intervention studies showed no impact on duration of delirium, mortality or institutionalization, but a decrease in severity of delirium and improvement in medium-term cognitive function were observed. The most commonly used interventions were temporal-spatial orientation, orientation to self and others, early mobilization and sleep hygiene. The four studies with pharmacological interventions found that rivastigmine reduced the duration of delirium, improved cognitive function and reduced caregiver burden; olanzapine and haloperidol decreased the severity of delirium; droperidol reduced length of hospitalization and improved delirium remission rate. CONCLUSION: Although the pharmacological approach has been used in the treatment of delirium among elderly, there have been few studies assessing its efficacy, involving a small number of patients. However, the improvements in delirium duration and severity suggest these drugs are effective in treating the condition. Once delirium has developed, non-pharmacological treatment seems less effective in controlling symptoms, and there is a lack of studies describing different non-pharmacological interventions.

Low band-to-band tunnelling and gate tunnelling current in novel nanoscale double-gate architecture: simulations and investigation

Energy Technology Data Exchange (ETDEWEB)

Datta, Deepanjan [Department of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47906 (United States); Ganguly, Samiran [Department of Electronics Engineering, Indian School of Mines, Dhanbad-826004 (India); Dasgupta, S [Department of Electronics and Computer Engineering, Indian Institute of Technology, Roorkee-247667 (India)

2007-05-30

Large band-to-band tunnelling (BTBT) and gate leakage current can limit scalability of nanoscale devices. In this paper, we have proposed a novel nanoscale parallel connected heteromaterial double gate (PCHEM-DG) architecture with triple metal gate which significantly suppress BTBT leakage, making it efficient for low power design in the sub-10 nm regime. We have also proposed a triple gate device with p{sup +} poly-n{sup +} poly-p{sup +} poly gate which has substantially low gate leakage over symmetric DG MOSFET. Simulations are performed using a 2D Poisson-Schroedinger simulator and verified with a 2D device simulator ATLAS. We conclude that, due to intrinsic body doping, negligible gate leakage, suppressed BTBT over symmetric DG devices, metal gate (MG) PCHEM-DG MOSFET is efficient for low power circuit design in the nanometre regime.

Pharmacology Portal: An Open Database for Clinical Pharmacologic Laboratory Services.

Science.gov (United States)

Karlsen Bjånes, Tormod; Mjåset Hjertø, Espen; Lønne, Lars; Aronsen, Lena; Andsnes Berg, Jon; Bergan, Stein; Otto Berg-Hansen, Grim; Bernard, Jean-Paul; Larsen Burns, Margrete; Toralf Fosen, Jan; Frost, Joachim; Hilberg, Thor; Krabseth, Hege-Merete; Kvan, Elena; Narum, Sigrid; Austgulen Westin, Andreas

2016-01-01

More than 50 Norwegian public and private laboratories provide one or more analyses for therapeutic drug monitoring or testing for drugs of abuse. Practices differ among laboratories, and analytical repertoires can change rapidly as new substances become available for analysis. The Pharmacology Portal was developed to provide an overview of these activities and to standardize the practices and terminology among laboratories. The Pharmacology Portal is a modern dynamic web database comprising all available analyses within therapeutic drug monitoring and testing for drugs of abuse in Norway. Content can be retrieved by using the search engine or by scrolling through substance lists. The core content is a substance registry updated by a national editorial board of experts within the field of clinical pharmacology. This ensures quality and consistency regarding substance terminologies and classification. All laboratories publish their own repertoires in a user-friendly workflow, adding laboratory-specific details to the core information in the substance registry. The user management system ensures that laboratories are restricted from editing content in the database core or in repertoires within other laboratory subpages. The portal is for nonprofit use, and has been fully funded by the Norwegian Medical Association, the Norwegian Society of Clinical Pharmacology, and the 8 largest pharmacologic institutions in Norway. The database server runs an open-source content management system that ensures flexibility with respect to further development projects, including the potential expansion of the Pharmacology Portal to other countries. Copyright © 2016 Elsevier HS Journals, Inc. All rights reserved.

Sliding-gate valve for use with abrasive materials

Science.gov (United States)

Ayers, Jr., William J.; Carter, Charles R.; Griffith, Richard A.; Loomis, Richard B.; Notestein, John E.

1985-01-01

The invention is a flow and pressure-sealing valve for use with abrasive solids. The valve embodies special features which provide for long, reliable operating lifetimes in solids-handling service. The valve includes upper and lower transversely slidable gates, contained in separate chambers. The upper gate provides a solids-flow control function, whereas the lower gate provides a pressure-sealing function. The lower gate is supported by means for (a) lifting that gate into sealing engagement with its seat when the gate is in its open and closed positions and (b) lowering the gate out of contact with its seat to permit abrasion-free transit of the gate between its open and closed positions. When closed, the upper gate isolates the lower gate from the solids. Because of this shielding action, the sealing surface of the lower gate is not exposed to solids during transit or when it is being lifted or lowered. The chamber containing the lower gate normally is pressurized slightly, and a sweep gas is directed inwardly across the lower-gate sealing surface during the vertical translation of the gate.

Photon-gated spin transistor

OpenAIRE

Li, Fan; Song, Cheng; Cui, Bin; Peng, Jingjing; Gu, Youdi; Wang, Guangyue; Pan, Feng

2017-01-01

Spin-polarized field-effect transistor (spin-FET), where a dielectric layer is generally employed for the electrical gating as the traditional FET, stands out as a seminal spintronic device under the miniaturization trend of electronics. It would be fundamentally transformative if optical gating was used for spin-FET. We report a new type of spin-polarized field-effect transistor (spin-FET) with optical gating, which is fabricated by partial exposure of the (La,Sr)MnO3 channel to light-emitti...

On photonic controlled phase gates

International Nuclear Information System (INIS)

Kieling, K; Eisert, J; O'Brien, J L

2010-01-01

As primitives for entanglement generation, controlled phase gates have a central role in quantum computing. Especially in ideas realizing instances of quantum computation in linear optical gate arrays, a closer look can be rewarding. In such architectures, all effective nonlinearities are induced by measurements. Hence the probability of success is a crucial parameter of such quantum gates. In this paper, we discuss this question for controlled phase gates that implement an arbitrary phase with one and two control qubits. Within the class of post-selected gates in dual-rail encoding with vacuum ancillas, we identify the optimal success probabilities. We construct networks that allow for implementation using current experimental capabilities in detail. The methods employed here appear specifically useful with the advent of integrated linear optical circuits, providing stable interferometers on monolithic structures.

Influence of ultra-thin TiN thickness (1.4 nm and 2.4 nm) on positive bias temperature instability (PBTI) of high-k/metal gate nMOSFETs with gate-last process

International Nuclear Information System (INIS)

Qi Lu-Wei; Yang Hong; Ren Shang-Qing; Xu Ye-Feng; Luo Wei-Chun; Xu Hao; Wang Yan-Rong; Tang Bo; Wang Wen-Wu; Yan Jiang; Zhu Hui-Long; Zhao Chao; Chen Da-Peng; Ye Tian-Chun

2015-01-01

The positive bias temperature instability (PBTI) degradations of high-k/metal gate (HK/MG) nMOSFETs with thin TiN capping layers (1.4 nm and 2.4 nm) are systemically investigated. In this paper, the trap energy distribution in gate stack during PBTI stress is extracted by using ramped recovery stress, and the temperature dependences of PBTI (90 °C, 125 °C, 160 °C) are studied and activation energy (E a ) values (0.13 eV and 0.15 eV) are extracted. Although the equivalent oxide thickness (EOT) values of two TiN thickness values are almost similar (0.85 nm and 0.87 nm), the 2.4-nm TiN one (thicker TiN capping layer) shows better PBTI reliability (13.41% at 0.9 V, 90 °C, 1000 s). This is due to the better interfacial layer/high-k (IL/HK) interface, and HK bulk states exhibited through extracting activation energy and trap energy distribution in the high-k layer. (paper)

Interface Study on Amorphous Indium Gallium Zinc Oxide Thin Film Transistors Using High-k Gate Dielectric Materials

Directory of Open Access Journals (Sweden)

Yu-Hsien Lin

2015-01-01

Full Text Available We investigated amorphous indium gallium zinc oxide (a-IGZO thin film transistors (TFTs using different high-k gate dielectric materials such as silicon nitride (Si3N4 and aluminum oxide (Al2O3 at low temperature process (<300°C and compared them with low temperature silicon dioxide (SiO2. The IGZO device with high-k gate dielectric material will expect to get high gate capacitance density to induce large amount of channel carrier and generate the higher drive current. In addition, for the integrating process of integrating IGZO device, postannealing treatment is an essential process for completing the process. The chemical reaction of the high-k/IGZO interface due to heat formation in high-k/IGZO materials results in reliability issue. We also used the voltage stress for testing the reliability for the device with different high-k gate dielectric materials and explained the interface effect by charge band diagram.

Interface Study on Amorphous Indium Gallium Zinc Oxide Thin Film Transistors Using High-k Gate Dielectric Materials

International Nuclear Information System (INIS)

Lin, Y. H.; Chou, J. C.

2015-01-01

We investigated amorphous indium gallium zinc oxide (a-IGZO) thin film transistors (TFT_s) using different high-Κ gate dielectric materials such as silicon nitride (Si_3N_4) and aluminum oxide (Al_2O_3) at low temperature process (<300 degree) and compared them with low temperature silicon dioxide (SiO_2). The IGZO device with high-Κ gate dielectric material will expect to get high gate capacitance density to induce large amount of channel carrier and generate the higher drive current. In addition, for the integrating process of integrating IGZO device, post annealing treatment is an essential process for completing the process. The chemical reaction of the high-κ/IGZO interface due to heat formation in high-Κ/IGZO materials results in reliability issue. We also used the voltage stress for testing the reliability for the device with different high-Κ gate dielectric materials and explained the interface effect by charge band diagram.

Reversible logic gates on Physarum Polycephalum

International Nuclear Information System (INIS)

Schumann, Andrew

2015-01-01

In this paper, we consider possibilities how to implement asynchronous sequential logic gates and quantum-style reversible logic gates on Physarum polycephalum motions. We show that in asynchronous sequential logic gates we can erase information because of uncertainty in the direction of plasmodium propagation. Therefore quantum-style reversible logic gates are more preferable for designing logic circuits on Physarum polycephalum

Stanford, Duke, Rice,... and Gates?

Science.gov (United States)

Carey, Kevin

2009-01-01

This article presents an open letter to Bill Gates. In his letter, the author suggests that Bill Gates should build a brand-new university, a great 21st-century institution of higher learning. This university will be unlike anything the world has ever seen. He asks Bill Gates not to stop helping existing colleges create the higher-education system…

Benchmarking gate-based quantum computers

Science.gov (United States)

Michielsen, Kristel; Nocon, Madita; Willsch, Dennis; Jin, Fengping; Lippert, Thomas; De Raedt, Hans

2017-11-01

With the advent of public access to small gate-based quantum processors, it becomes necessary to develop a benchmarking methodology such that independent researchers can validate the operation of these processors. We explore the usefulness of a number of simple quantum circuits as benchmarks for gate-based quantum computing devices and show that circuits performing identity operations are very simple, scalable and sensitive to gate errors and are therefore very well suited for this task. We illustrate the procedure by presenting benchmark results for the IBM Quantum Experience, a cloud-based platform for gate-based quantum computing.

MOSFET Degradation Under RF Stress

NARCIS (Netherlands)

Sasse, G.T.; Kuper, F.G.; Schmitz, Jurriaan

2008-01-01

We report on the degradation of MOS transistors under RF stress. Hot-carrier degradation, negative-bias temperature instability, and gate dielectric breakdown are investigated. The findings are compared to established voltage- and field-driven models. The experimental results indicate that the

Gate Engineering in SOI LDMOS for Device Reliability

Directory of Open Access Journals (Sweden)

Aanand

2016-01-01

Full Text Available A linearly graded doping drift region with step gate structure, used for improvement of reduced surface field (RESURF SOI LDMOS transistor performance has been simulated with 0.35µm technology in this paper. The proposed device has one poly gate and double metal gate arranged in a stepped manner, from channel to drift region. The first gate uses n+ poly (near source where as other two gates of aluminium. The first gate with thin gate oxide has good control over the channel charge. The third gate with thick gate oxide at drift region reduce gate to drain capacitance. The arrangement of second and third gates in a stepped manner in drift region spreads the electric field uniformly. Using two dimensional device simulations, the proposed SOI LDMOS is compared with conventional structure and the extended metal structure. We demonstrate that the proposed device exhibits significant enhancement in linearity, breakdown voltage, on-resistance and HCI. Double metal gate reduces the impact ionization area which helps to improve the Hot Carrier Injection effect..

CMOS gate array characterization procedures

Science.gov (United States)

Spratt, James P.

1993-09-01

Present procedures are inadequate for characterizing the radiation hardness of gate array product lines prior to personalization because the selection of circuits to be used, from among all those available in the manufacturer's circuit library, is usually uncontrolled. (Some circuits are fundamentally more radiation resistant than others.) In such cases, differences in hardness can result between different designs of the same logic function. Hardness also varies because many gate arrays feature large custom-designed megacells (e.g., microprocessors and random access memories-MicroP's and RAM's). As a result, different product lines cannot be compared equally. A characterization strategy is needed, along with standardized test vehicle(s), methodology, and conditions, so that users can make informed judgments on which gate arrays are best suited for their needs. The program described developed preferred procedures for the radiation characterization of gate arrays, including a gate array evaluation test vehicle, featuring a canary circuit, designed to define the speed versus hardness envelope of the gate array. A multiplier was chosen for this role, and a baseline multiplier architecture is suggested that could be incorporated into an existing standard evaluation circuit chip.

GATE: Improving the computational efficiency

International Nuclear Information System (INIS)

Staelens, S.; De Beenhouwer, J.; Kruecker, D.; Maigne, L.; Rannou, F.; Ferrer, L.; D'Asseler, Y.; Buvat, I.; Lemahieu, I.

2006-01-01

GATE is a software dedicated to Monte Carlo simulations in Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET). An important disadvantage of those simulations is the fundamental burden of computation time. This manuscript describes three different techniques in order to improve the efficiency of those simulations. Firstly, the implementation of variance reduction techniques (VRTs), more specifically the incorporation of geometrical importance sampling, is discussed. After this, the newly designed cluster version of the GATE software is described. The experiments have shown that GATE simulations scale very well on a cluster of homogeneous computers. Finally, an elaboration on the deployment of GATE on the Enabling Grids for E-Science in Europe (EGEE) grid will conclude the description of efficiency enhancement efforts. The three aforementioned methods improve the efficiency of GATE to a large extent and make realistic patient-specific overnight Monte Carlo simulations achievable

Stress Effects on Multiple Memory System Interactions

OpenAIRE

Ness, Deborah; Calabrese, Pasquale

2016-01-01

Extensive behavioural, pharmacological, and neurological research reports stress effects on mammalian memory processes. While stress effects on memory quantity have been known for decades, the influence of stress on multiple memory systems and their distinct contributions to the learning process have only recently been described. In this paper, after summarizing the fundamental biological aspects of stress/emotional arousal and recapitulating functionally and anatomically distinct memory syst...

Dual-gated cardiac PET-clinical feasibility study

Energy Technology Data Exchange (ETDEWEB)

Teraes, Mika; Kokki, Tommi; Noponen, Tommi; Hoppela, Erika; Sipilae, Hannu T.; Knuuti, Juhani [Turku PET Centre, PO BOX 52, Turku (Finland); Durand-Schaefer, Nicolas [General Electric Medical Systems, Buc (France); Pietilae, Mikko [Turku University Hospital, Department of Internal Medicine, Turku (Finland); Kiss, Jan [Turku University Hospital, Department of Surgery, Turku (Finland)

2010-03-15

Both respiratory and cardiac motions reduce image quality in myocardial imaging. For accurate imaging of small structures such as vulnerable coronary plaques, simultaneous cardiac and respiratory gating is warranted. This study tests the feasibility of a recently developed robust method for cardiac-respiratory gating. List-mode data with triggers from respiratory and cardiac cycles are rearranged into dual-gated segments and reconstructed with standard algorithms of a commercial PET/CT scanner. Cardiac gates were defined as three fixed phases and one variable diastolic phase. Chest motion was measured with a respiratory gating device and post-processed to determine gates. Preservation of quantification in dual-gated images was tested with an IEC whole-body phantom. Minipig and human studies were performed to evaluate the feasibility of the method. In minipig studies, a coronary catheter with radioactive tip was guided in coronary artery for in vivo and ex vivo acquisitions. Dual gating in humans with suspected cardiac disorders was performed using 18-F-FDG as a tracer. The method was found feasible for in vivo imaging and the radioactive catheter tip was better resolved in gated images. In human studies, the dual gating was found feasible and easy for clinical routine. Maximal movement of myocardial surface in cranio-caudal direction was over 20 mm. The shape of myocardium was clearly different between the gates and papillary muscles become more visible in diastolic images. The first clinical experiences using robust cardiac-respiratory dual gating are encouraging. Further testing in larger clinical populations using tracers designed especially for plaque imaging is warranted. (orig.)

Dual-gated cardiac PET-clinical feasibility study

International Nuclear Information System (INIS)

Teraes, Mika; Kokki, Tommi; Noponen, Tommi; Hoppela, Erika; Sipilae, Hannu T.; Knuuti, Juhani; Durand-Schaefer, Nicolas; Pietilae, Mikko; Kiss, Jan

2010-01-01

Both respiratory and cardiac motions reduce image quality in myocardial imaging. For accurate imaging of small structures such as vulnerable coronary plaques, simultaneous cardiac and respiratory gating is warranted. This study tests the feasibility of a recently developed robust method for cardiac-respiratory gating. List-mode data with triggers from respiratory and cardiac cycles are rearranged into dual-gated segments and reconstructed with standard algorithms of a commercial PET/CT scanner. Cardiac gates were defined as three fixed phases and one variable diastolic phase. Chest motion was measured with a respiratory gating device and post-processed to determine gates. Preservation of quantification in dual-gated images was tested with an IEC whole-body phantom. Minipig and human studies were performed to evaluate the feasibility of the method. In minipig studies, a coronary catheter with radioactive tip was guided in coronary artery for in vivo and ex vivo acquisitions. Dual gating in humans with suspected cardiac disorders was performed using 18-F-FDG as a tracer. The method was found feasible for in vivo imaging and the radioactive catheter tip was better resolved in gated images. In human studies, the dual gating was found feasible and easy for clinical routine. Maximal movement of myocardial surface in cranio-caudal direction was over 20 mm. The shape of myocardium was clearly different between the gates and papillary muscles become more visible in diastolic images. The first clinical experiences using robust cardiac-respiratory dual gating are encouraging. Further testing in larger clinical populations using tracers designed especially for plaque imaging is warranted. (orig.)

Demonstration of a Quantum Nondemolition Sum Gate

DEFF Research Database (Denmark)

Yoshikawa, J.; Miwa, Y.; Huck, Alexander

2008-01-01

The sum gate is the canonical two-mode gate for universal quantum computation based on continuous quantum variables. It represents the natural analogue to a qubit C-NOT gate. In addition, the continuous-variable gate describes a quantum nondemolition (QND) interaction between the quadrature...

Single Event Gate Rupture in 130-nm CMOS Transistor Arrays Subjected to X-Ray Irradiation

CERN Document Server

Silvestri, M; Gerardin, Simone; Faccio, Federico; Paccagnella, Alessandro

2010-01-01

We present new experimental results on heavy ion-induced gate rupture on deep submicron CMOS transistor arrays. Through the use of dedicated test structures, composed by a large number of 130-nm MOSFETs connected in parallel, we show the response to heavy ion irradiation under high stress voltages of devices previously irradiated with X-rays. We found only a slight impact on gate rupture critical voltage at a LET of 32 MeV cm(2) mg(-1) for devices previously irradiated up to 3 Mrad(SiO2), and practically no change for 100 Mrad(SiO2) irradiation, dose of interest for the future super large hadron collider (SLHC).

Stress magnetic resonance imaging in coronary artery disease. 11

International Nuclear Information System (INIS)

Pennell, D.J.; Underwood, S.R.

1991-01-01

The feasibility of MRI of wall motion and cardiovascular haemodynamics has been investigated during pharmacological stress with dipyridamole and dobutamine as pharmacological stressors. The authors conclude that dobutamine is preferable to dipyridamole for inducing myocardial ischemia during imaging. (H.W.). 74 refs.; 8 figs.; 5 tabs

High performance organic field-effect transistors with ultra-thin HfO2 gate insulator deposited directly onto the organic semiconductor

International Nuclear Information System (INIS)

Ono, S.; Häusermann, R.; Chiba, D.; Shimamura, K.; Ono, T.; Batlogg, B.

2014-01-01

We have produced stable organic field-effect transistors (OFETs) with an ultra-thin HfO 2 gate insulator deposited directly on top of rubrene single crystals by atomic layer deposition (ALD). We find that ALD is a gentle deposition process to grow thin films without damaging rubrene single crystals, as results these devices have a negligibly small threshold voltage and are very stable against gate-bias-stress, and the mobility exceeds 1 cm 2 /V s. Moreover, the devices show very little degradation even when kept in air for more than 2 months. These results demonstrate thin HfO 2 layers deposited by ALD to be well suited as high capacitance gate dielectrics in OFETs operating at small gate voltage. In addition, the dielectric layer acts as an effective passivation layer to protect the organic semiconductor

Safety of adenosine in stress cerebral perfusion imaging

International Nuclear Information System (INIS)

Hu Pengcheng; Gu Yushen; Liu Wenguan; Xiu Yan; Zhu Weimin; Chen Shuguang; Shi Hongcheng

2009-01-01

Objective: To evaluate the safety of adenosine as pharmacological stress agents in stress cerebral perfusion imaging. Methods: Eighty patients under investigation for suspected cerebral vessel disease were recruited. Each had a resting scan and a stress scan on different days. The adenosine stress protocol was as same as the protocol used in adenosine stress myocardial perfusion imaging. Subjective and objective side-effects were investigated during pharmacological stress procedure. Results: All patients completed the 6 min infusion protocol without premature termination on safety criteria or due to intolerable symptoms. 46 patients had mild side effects. 20 patients (25%) had dizziness, 12 patients (15%) had palpitation, 1 patient (1%) was hypotensive, 7 patients (9%) had dyspnoea, 4 patients (5%) felt hot, 3 patients (4%) had sweat, 4 patients (5%) had nausea, 6 patients (8%) had flushing, 19 patients (24%) had chest pain, 6 patients (8%) had abdomen pain, 3 patients (4%) had abnormal taste and 1 patient (1%) were thirsty. Transient ST change occurred in only 1 patient. Conclusion: Adenosine stress cerebral perfusion imaging is a safe diagnostic method with mild side effects. (authors)

Multi-gated field emitters for a micro-column

International Nuclear Information System (INIS)

Mimura, Hidenori; Kioke, Akifumi; Aoki, Toru; Neo, Yoichiro; Yoshida, Tomoya; Nagao, Masayoshi

2011-01-01

We have developed a multi-gated field emitter (FE) such as a quadruple-gated FE with a three-stacked electrode lens and a quintuple-gated FE with a four-stacked electrode lens. Both the FEs can focus the electron beam. However, the quintuple-gated FE has a stronger electron convergence than the quadruple-gated FE, and a beam crossover is clearly observed for the quintuple-gated FE.

Process Pharmacology: A Pharmacological Data Science Approach to Drug Development and Therapy.

Science.gov (United States)

Lötsch, Jörn; Ultsch, Alfred

2016-04-01

A novel functional-genomics based concept of pharmacology that uses artificial intelligence techniques for mining and knowledge discovery in "big data" providing comprehensive information about the drugs' targets and their functional genomics is proposed. In "process pharmacology", drugs are associated with biological processes. This puts the disease, regarded as alterations in the activity in one or several cellular processes, in the focus of drug therapy. In this setting, the molecular drug targets are merely intermediates. The identification of drugs for therapeutic or repurposing is based on similarities in the high-dimensional space of the biological processes that a drug influences. Applying this principle to data associated with lymphoblastic leukemia identified a short list of candidate drugs, including one that was recently proposed as novel rescue medication for lymphocytic leukemia. The pharmacological data science approach provides successful selections of drug candidates within development and repurposing tasks. © 2016 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

An evaluation of gating window size, delivery method, and composite field dosimetry of respiratory-gated IMRT

International Nuclear Information System (INIS)

Hugo, Geoffrey D.; Agazaryan, Nzhde; Solberg, Timothy D.

2002-01-01

A respiratory gating system has been developed based on a commercial patient positioning system. The purpose of this study is to investigate the ability of the gating system to reproduce normal, nongated IMRT operation and to quantify the errors produced by delivering a nongated IMRT treatment onto a moving target. A moving phantom capable of simultaneous two-dimensional motion was built, and an analytical liver motion function was used to drive the phantom. Studies were performed to assess the effect of gating window size and choice of delivery method (segmented and dynamic multileaf collimation). Additionally, two multiple field IMRT cases were delivered to quantify the error in gated and nongated IMRT with motion. Dosimetric error between nonmoving and moving deliveries is related to gating window size. By reducing the window size, the error can be reduced. Delivery error can be reduced for both dynamic and segmented delivery with gating. For the implementation of dynamic IMRT delivery in this study, dynamic delivery was found to generate larger delivery errors than segmented delivery in most cases studied. For multiple field IMRT delivery, the largest errors were generated in regions where high field modulation was present parallel to the axis of motion. Gating was found to reduce these large errors to clinically acceptable levels

Prognostic significance of stress myocardial gated SPECT among Japanese patients referred for coronary angiography: A study of data from the J-ACCESS database

Energy Technology Data Exchange (ETDEWEB)

Momose, Mitsuru [Tokyo Women' s Medical University, Department of Radiology, Tokyo (Japan); Nakajima, Kenichi [Kanazawa University Hospital, Department of Nuclear Medicine, Kanazawa (Japan); Nishimura, Tsunehiko [Kyoto Prefectural University of Medicine, Department of Radiology, Graduate School of Medical Science, Kyoto (Japan)

2009-08-15

The J-ACCESS [Japanese investigation of prognosis based on gated single photon emission computed tomography (SPECT)] study found that quantitative gated myocardial SPECT (QGS) is valuable for predicting the prognosis of Japanese patients with known or suspected ischaemic heart disease. The present study evaluates the incremental prognostic value of myocardial perfusion imaging (MPI) with QGS among patients referred for coronary angiography (CAG). Among 4,031 Japanese patients registered at 117 hospitals for the J-ACCESS study, we selected 1,011 who underwent CAG within 3 months before or after MPI with QGS. Summed stress, rest and difference scores (SSS, SRS and SDS) were generated from myocardial perfusion images using a 20-segment scoring system. Myocardial ischaemia was judged visually. End-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were determined by QGS. Numbers of diseased (> 75% stenosis) coronary vessels (CDV) were assessed by CAG. All patients were followed up for 3 years to determine cardiac events (CE) including cardiac death, non-fatal myocardial infarction and severe heart failure. Univariate and multivariate analyses of prognostic ability included age, cardiac risk factors (hypertension, hyperlipidaemia, diabetes mellitus and prior myocardial infarction), angiographic findings and the QGS parameters as independent variables. Cardiac events occurred more frequently with increasing numbers of coronary vessel lesions (p=0.0016). Cox univariate analysis revealed that diabetes, CDV, SSS, SDS, EDV, ESV and EF were significant predictors (Wald {chi}{sup 2}=5.99, 12.9, 8.39, 9.11, 35.5, 42.1 and 31.1, respectively), whereas multivariate analysis selected only ESV and SDS as significant predictors (Wald {chi}{sup 2}=36.4, 8.4; p = 0.0038, p < 0.001). MPI with QGS, especially with gated functional data, has incremental prognostic value in addition to angiographic findings. MPI with QGS findings predominantly contribute to the

International Union of Basic and Clinical Pharmacology. C. Nomenclature and Properties of Calcium-Activated and Sodium-Activated Potassium Channels.

Science.gov (United States)

Kaczmarek, Leonard K; Aldrich, Richard W; Chandy, K George; Grissmer, Stephan; Wei, Aguan D; Wulff, Heike

2017-01-01

A subset of potassium channels is regulated primarily by changes in the cytoplasmic concentration of ions, including calcium, sodium, chloride, and protons. The eight members of this subfamily were originally all designated as calcium-activated channels. More recent studies have clarified the gating mechanisms for these channels and have documented that not all members are sensitive to calcium. This article describes the molecular relationships between these channels and provides an introduction to their functional properties. It also introduces a new nomenclature that differentiates between calcium- and sodium-activated potassium channels. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Effects of heat stress on baroreflex function in humans

Science.gov (United States)

Crandall, Craig G.; Cui, Jian; Wilson, Thad E.

2003-01-01

INTRODUCTION: Heat stress significantly reduces orthostatic tolerance in humans. The mechanism(s) causing this response remain unknown. The purpose of this review article is to present data pertaining to the hypothesis that reduced orthostatic tolerance in heat stressed individuals is a result of heat stress induced alterations in baroflex function. METHODS: In both normothermic and heat stressed conditions baroreflex responsiveness was assessed via pharmacological and non-pharmacological methods. In addition, the effects of heat stress on post-synaptic vasoconstrictor responsiveness were assessed. RESULTS: Generally, whole body heating did not alter baroreflex sensitivity defined as the gain of the linear portion of the baroreflex curve around the operating point. However, whole body heating shifted the baroreflex curve to the prevailing (i.e. elevated) heart rate and muscle sympathetic nerve activity. Finally, the heat stress impaired vasoconstrictor responses to exogenous administration of adrenergic agonists. CONCLUSION: Current data do not support the hypothesis that reduced orthostatic tolerance associated with heat stress in humans is due to impaired baroreflex responsiveness. This phenomenon may be partially due to the effects of heat stress on reducing vasoconstrictor responsiveness.

Double optical gating

Science.gov (United States)

Gilbertson, Steve

The observation and control of dynamics in atomic and molecular targets requires the use of laser pulses with duration less than the characteristic timescale of the process which is to be manipulated. For electron dynamics, this time scale is on the order of attoseconds where 1 attosecond = 10 -18 seconds. In order to generate pulses on this time scale, different gating methods have been proposed. The idea is to extract or "gate" a single pulse from an attosecond pulse train and switch off all the other pulses. While previous methods have had some success, they are very difficult to implement and so far very few labs have access to these unique light sources. The purpose of this work is to introduce a new method, called double optical gating (DOG), and to demonstrate its effectiveness at generating high contrast single isolated attosecond pulses from multi-cycle lasers. First, the method is described in detail and is investigated in the spectral domain. The resulting attosecond pulses produced are then temporally characterized through attosecond streaking. A second method of gating, called generalized double optical gating (GDOG), is also introduced. This method allows attosecond pulse generation directly from a carrier-envelope phase un-stabilized laser system for the first time. Next the methods of DOG and GDOG are implemented in attosecond applications like high flux pulses and extreme broadband spectrum generation. Finally, the attosecond pulses themselves are used in experiments. First, an attosecond/femtosecond cross correlation is used for characterization of spatial and temporal properties of femtosecond pulses. Then, an attosecond pump, femtosecond probe experiment is conducted to observe and control electron dynamics in helium for the first time.

Multi detector computed tomography (MDCT) of the aortic root; ECG-gated verses non-ECG-gated examinations

International Nuclear Information System (INIS)

Kristiansen, Joanna; Guenther, Anne; Aalokken, Trond Mogens; Andersen, Rune

2011-01-01

Purpose: Motion artifacts may degrade a conventional CT examination of the ascending aorta and hinder accurate diagnosis. We quantitatively compared retrospectively electrocardiographic (ECG) -gated multi detector computed tomography (MDCT) with non-ECG-gated MDCT in order to demonstrate whether or not one of the methods should be preferred. Method: The study included seventeen patients with surgically reconstructed aortic root and reimplanted coronary arteries. All patients had undergone both non-gated MDCT and retrospectively ECG-gated MDCT employing a stringently modulated tube current with single phase image reconstruction. The incidence of motion artifacts in the left main coronary artery (LM), proximal right coronary artery (RCA), and aortic root and ascending aorta were rated using a four point scale. The effective dose for each scan was calculated and normalized to a 15 cm scan length. Statistical analysis of motion artifacts and radiation dose was performed using Wilcoxon matched pairs signed rank sum test. Results: A significant reduction in motion artifacts was found in all three vessels in images from the retrospectively ECG-gated scans (LM: P = 0.005, RCA: P = 0.015, aorta: P = 0.003). The mean normalized effective radiation dose was 3.69 mSv (±1.03) for the non-ECG-gated scans and 16.37 mSv (±2.53) for the ECG-gated scans. Conclusion: Retrospective ECG-gating with single phase reconstruction significantly reduces the incidence of motion artifacts in the aortic root and the proximal portion of the coronary arteries but at the expense of a fourfold increase in radiation dose.

Cardiac gated ventilation

International Nuclear Information System (INIS)

Hanson, C.W. III; Hoffman, E.A.

1995-01-01

There are several theoretic advantages to synchronizing positive pressure breaths with the cardiac cycle, including the potential for improving distribution of pulmonary and myocardial blood flow and enhancing cardiac output. The authors evaluated the effects of synchronizing respiration to the cardiac cycle using a programmable ventilator and electron beam CT (EBCT) scanning. The hearts of anesthetized dogs were imaged during cardiac gated respiration with a 50 msec scan aperture. Multi slice, short axis, dynamic image data sets spanning the apex to base of the left ventricle were evaluated to determine the volume of the left ventricular chamber at end-diastole and end-systole during apnea, systolic and diastolic cardiac gating. The authors observed an increase in cardiac output of up to 30% with inspiration gated to the systolic phase of the cardiac cycle in a non-failing model of the heart

Nanosecond pulsed electric fields depolarize transmembrane potential via voltage-gated K+, Ca2+ and TRPM8 channels in U87 glioblastoma cells.

Science.gov (United States)

Burke, Ryan C; Bardet, Sylvia M; Carr, Lynn; Romanenko, Sergii; Arnaud-Cormos, Delia; Leveque, Philippe; O'Connor, Rodney P

2017-10-01

Nanosecond pulsed electric fields (nsPEFs) have a variety of applications in the biomedical and biotechnology industries. Cancer treatment has been at the forefront of investigations thus far as nsPEFs permeabilize cellular and intracellular membranes leading to apoptosis and necrosis. nsPEFs may also influence ion channel gating and have the potential to modulate cell physiology without poration of the membrane. This phenomenon was explored using live cell imaging and a sensitive fluorescent probe of transmembrane voltage in the human glioblastoma cell line, U87 MG, known to express a number of voltage-gated ion channels. The specific ion channels involved in the nsPEF response were screened using a membrane potential imaging approach and a combination of pharmacological antagonists and ion substitutions. It was found that a single 10ns pulsed electric field of 34kV/cm depolarizes the transmembrane potential of cells by acting on specific voltage-sensitive ion channels; namely the voltage and Ca2 + gated BK potassium channel, L- and T-type calcium channels, and the TRPM8 transient receptor potential channel. Copyright © 2017 Elsevier B.V. All rights reserved.

Caenorhabditis elegans as Model System in Pharmacology and Toxicology: Effects of Flavonoids on Redox-Sensitive Signalling Pathways and Ageing

Directory of Open Access Journals (Sweden)

Karoline Koch

2014-01-01

Full Text Available Flavonoids are secondary plant compounds that mediate diverse biological activities, for example, by scavenging free radicals and modulating intracellular signalling pathways. It has been shown in various studies that distinct flavonoid compounds enhance stress resistance and even prolong the life span of organisms. In the last years the model organism C. elegans has gained increasing importance in pharmacological and toxicological sciences due to the availability of various genetically modified nematode strains, the simplicity of modulating genes by RNAi, and the relatively short life span. Several studies have been performed demonstrating that secondary plant compounds influence ageing, stress resistance, and distinct signalling pathways in the nematode. Here we present an overview of the modulating effects of different flavonoids on oxidative stress, redox-sensitive signalling pathways, and life span in C. elegans introducing the usability of this model system for pharmacological and toxicological research.

Caenorhabditis elegans as Model System in Pharmacology and Toxicology: Effects of Flavonoids on Redox-Sensitive Signalling Pathways and Ageing

Science.gov (United States)

Koch, Karoline; Havermann, Susannah; Büchter, Christian

2014-01-01

Flavonoids are secondary plant compounds that mediate diverse biological activities, for example, by scavenging free radicals and modulating intracellular signalling pathways. It has been shown in various studies that distinct flavonoid compounds enhance stress resistance and even prolong the life span of organisms. In the last years the model organism C. elegans has gained increasing importance in pharmacological and toxicological sciences due to the availability of various genetically modified nematode strains, the simplicity of modulating genes by RNAi, and the relatively short life span. Several studies have been performed demonstrating that secondary plant compounds influence ageing, stress resistance, and distinct signalling pathways in the nematode. Here we present an overview of the modulating effects of different flavonoids on oxidative stress, redox-sensitive signalling pathways, and life span in C. elegans introducing the usability of this model system for pharmacological and toxicological research. PMID:24895670

Double-gated spectral snapshots for biomolecular fluorescence

International Nuclear Information System (INIS)

Nakamura, Ryosuke; Hamada, Norio; Ichida, Hideki; Tokunaga, Fumio; Kanematsu, Yasuo

2007-01-01

A versatile method to take femtosecond spectral snapshots of fluorescence has been developed based on a double gating technique in the combination of an optical Kerr gate and an image intensifier as an electrically driven gate set in front of a charge-coupled device detector. The application of a conventional optical-Kerr-gate method is limited to molecules with the short fluorescence lifetime up to a few hundred picoseconds, because long-lifetime fluorescence itself behaves as a source of the background signal due to insufficiency of the extinction ratio of polarizers employed for the Kerr gate. By using the image intensifier with the gate time of 200 ps, we have successfully suppressed the background signal and overcome the application limit of optical-Kerr-gate method. The system performance has been demonstrated by measuring time-resolved fluorescence spectra for laser dye solution and the riboflavin solution as a typical sample of biomolecule

SU-E-T-350: Verification of Gating Performance of a New Elekta Gating Solution: Response Kit and Catalyst System

Energy Technology Data Exchange (ETDEWEB)

Xie, X; Cao, D; Housley, D; Mehta, V; Shepard, D [Swedish Cancer Institute, Seattle, WA (United States)

2014-06-01

Purpose: In this work, we have tested the performance of new respiratory gating solutions for Elekta linacs. These solutions include the Response gating and the C-RAD Catalyst surface mapping system.Verification measurements have been performed for a series of clinical cases. We also examined the beam on latency of the system and its impact on delivery efficiency. Methods: To verify the benefits of tighter gating windows, a Quasar Respiratory Motion Platform was used. Its vertical-motion plate acted as a respiration surrogate and was tracked by the Catalyst system to generate gating signals. A MatriXX ion-chamber array was mounted on its longitudinal-moving platform. Clinical plans are delivered to a stationary and moving Matrix array at 100%, 50% and 30% gating windows and gamma scores were calculated comparing moving delivery results to the stationary result. It is important to note that as one moves to tighter gating windows, the delivery efficiency will be impacted by the linac's beam-on latency. Using a specialized software package, we generated beam-on signals of lengths of 1000ms, 600ms, 450ms, 400ms, 350ms and 300ms. As the gating windows get tighter, one can expect to reach a point where the dose rate will fall to nearly zero, indicating that the gating window is close to beam-on latency. A clinically useful gating window needs to be significantly longer than the latency for the linac. Results: As expected, the use of tighter gating windows improved delivery accuracy. However, a lower limit of the gating window, largely defined by linac beam-on latency, exists at around 300ms. Conclusion: The Response gating kit, combined with the C-RAD Catalyst, provides an effective solution for respiratorygated treatment delivery. Careful patient selection, gating window design, even visual/audio coaching may be necessary to ensure both delivery quality and efficiency. This research project is funded by Elekta.

Voltage-Gated Potassium Channels: A Structural Examination of Selectivity and Gating

Science.gov (United States)

Kim, Dorothy M.; Nimigean, Crina M.

2016-01-01

Voltage-gated potassium channels play a fundamental role in the generation and propagation of the action potential. The discovery of these channels began with predictions made by early pioneers, and has culminated in their extensive functional and structural characterization by electrophysiological, spectroscopic, and crystallographic studies. With the aid of a variety of crystal structures of these channels, a highly detailed picture emerges of how the voltage-sensing domain reports changes in the membrane electric field and couples this to conformational changes in the activation gate. In addition, high-resolution structural and functional studies of K+ channel pores, such as KcsA and MthK, offer a comprehensive picture on how selectivity is achieved in K+ channels. Here, we illustrate the remarkable features of voltage-gated potassium channels and explain the mechanisms used by these machines with experimental data. PMID:27141052

Audio-visual biofeedback for respiratory-gated radiotherapy: Impact of audio instruction and audio-visual biofeedback on respiratory-gated radiotherapy

International Nuclear Information System (INIS)

George, Rohini; Chung, Theodore D.; Vedam, Sastry S.; Ramakrishnan, Viswanathan; Mohan, Radhe; Weiss, Elisabeth; Keall, Paul J.

2006-01-01

Purpose: Respiratory gating is a commercially available technology for reducing the deleterious effects of motion during imaging and treatment. The efficacy of gating is dependent on the reproducibility within and between respiratory cycles during imaging and treatment. The aim of this study was to determine whether audio-visual biofeedback can improve respiratory reproducibility by decreasing residual motion and therefore increasing the accuracy of gated radiotherapy. Methods and Materials: A total of 331 respiratory traces were collected from 24 lung cancer patients. The protocol consisted of five breathing training sessions spaced about a week apart. Within each session the patients initially breathed without any instruction (free breathing), with audio instructions and with audio-visual biofeedback. Residual motion was quantified by the standard deviation of the respiratory signal within the gating window. Results: Audio-visual biofeedback significantly reduced residual motion compared with free breathing and audio instruction. Displacement-based gating has lower residual motion than phase-based gating. Little reduction in residual motion was found for duty cycles less than 30%; for duty cycles above 50% there was a sharp increase in residual motion. Conclusions: The efficiency and reproducibility of gating can be improved by: incorporating audio-visual biofeedback, using a 30-50% duty cycle, gating during exhalation, and using displacement-based gating

Image quality in non-gated versus gated reconstruction of tongue motion using magnetic resonance imaging: a comparison using automated image processing

Energy Technology Data Exchange (ETDEWEB)

Alvey, Christopher; Orphanidou, C.; Coleman, J.; McIntyre, A.; Golding, S.; Kochanski, G. [University of Oxford, Oxford (United Kingdom)

2008-11-15

The use of gated or ECG triggered MR is a well-established technique and developments in coil technology have enabled this approach to be applied to areas other than the heart. However, the image quality of gated (ECG or cine) versus non-gated or real-time has not been extensively evaluated in the mouth. We evaluate two image sequences by developing an automatic image processing technique which compares how well the image represents known anatomy. Four subjects practised experimental poly-syllabic sentences prior to MR scanning. Using a 1.5 T MR unit, we acquired comparable gated (using an artificial trigger) and non-gated sagittal images during speech. We then used an image processing algorithm to model the image grey along lines that cross the airway. Each line involved an eight parameter non-linear equation to model of proton densities, edges, and dimensions. Gated and non-gated images show similar spatial resolution, with non-gated images being slightly sharper (10% better resolution, less than 1 pixel). However, the gated sequences generated images of substantially lower inherent noise, and substantially better discrimination between air and tissue. Additionally, the gated sequences demonstrate a very much greater temporal resolution. Overall, image quality is better with gated imaging techniques, especially given their superior temporal resolution. Gated techniques are limited by the repeatability of the motions involved, and we have shown that speech to a metronome can be sufficiently repeatable to allow high-quality gated magnetic resonance imaging images. We suggest that gated sequences may be useful for evaluating other types of repetitive movement involving the joints and limb motions. (orig.)

Image quality in non-gated versus gated reconstruction of tongue motion using magnetic resonance imaging: a comparison using automated image processing

International Nuclear Information System (INIS)

Alvey, Christopher; Orphanidou, C.; Coleman, J.; McIntyre, A.; Golding, S.; Kochanski, G.

2008-01-01

The use of gated or ECG triggered MR is a well-established technique and developments in coil technology have enabled this approach to be applied to areas other than the heart. However, the image quality of gated (ECG or cine) versus non-gated or real-time has not been extensively evaluated in the mouth. We evaluate two image sequences by developing an automatic image processing technique which compares how well the image represents known anatomy. Four subjects practised experimental poly-syllabic sentences prior to MR scanning. Using a 1.5 T MR unit, we acquired comparable gated (using an artificial trigger) and non-gated sagittal images during speech. We then used an image processing algorithm to model the image grey along lines that cross the airway. Each line involved an eight parameter non-linear equation to model of proton densities, edges, and dimensions. Gated and non-gated images show similar spatial resolution, with non-gated images being slightly sharper (10% better resolution, less than 1 pixel). However, the gated sequences generated images of substantially lower inherent noise, and substantially better discrimination between air and tissue. Additionally, the gated sequences demonstrate a very much greater temporal resolution. Overall, image quality is better with gated imaging techniques, especially given their superior temporal resolution. Gated techniques are limited by the repeatability of the motions involved, and we have shown that speech to a metronome can be sufficiently repeatable to allow high-quality gated magnetic resonance imaging images. We suggest that gated sequences may be useful for evaluating other types of repetitive movement involving the joints and limb motions. (orig.)

High-fidelity gates in quantum dot spin qubits.

Science.gov (United States)

Koh, Teck Seng; Coppersmith, S N; Friesen, Mark

2013-12-03

Several logical qubits and quantum gates have been proposed for semiconductor quantum dots controlled by voltages applied to top gates. The different schemes can be difficult to compare meaningfully. Here we develop a theoretical framework to evaluate disparate qubit-gating schemes on an equal footing. We apply the procedure to two types of double-dot qubits: the singlet-triplet and the semiconducting quantum dot hybrid qubit. We investigate three quantum gates that flip the qubit state: a DC pulsed gate, an AC gate based on logical qubit resonance, and a gate-like process known as stimulated Raman adiabatic passage. These gates are all mediated by an exchange interaction that is controlled experimentally using the interdot tunnel coupling g and the detuning [Symbol: see text], which sets the energy difference between the dots. Our procedure has two steps. First, we optimize the gate fidelity (f) for fixed g as a function of the other control parameters; this yields an f(opt)(g) that is universal for different types of gates. Next, we identify physical constraints on the control parameters; this yields an upper bound f(max) that is specific to the qubit-gate combination. We show that similar gate fidelities (~99:5%) should be attainable for singlet-triplet qubits in isotopically purified Si, and for hybrid qubits in natural Si. Considerably lower fidelities are obtained for GaAs devices, due to the fluctuating magnetic fields ΔB produced by nuclear spins.

Retrospectively ECG-gated multi-detector row CT of the chest: does ECG-gating improve three-dimensional visualization of the bronchial tree?

International Nuclear Information System (INIS)

Schertler, T.; Wildermuth, S.; Willmann, J.K.; Crook, D.W.; Marincek, B.; Boehm, T.

2004-01-01

Purpose: To determine the impact of retrospectively ECG-gated multi-detector row CT (MDCT) on three-dimensional (3D) visualization of the bronchial tree and virtual bronchoscopy (VB) as compared to non-ECG-gated data acquisition. Materials and Methods: Contrast-enhanced retrospectively ECG-gated and non-ECG-gated MDCT of the chest was performed in 25 consecutive patients referred for assessment of coronary artery bypass grafts and pathology of the ascending aorta. ECG-gated MDCT data were reconstructed in diastole using an absolute reverse delay of -400 msec in all patients. In 10 patients additional reconstructions at -200 msec, -300 msec, and -500 msec prior to the R-wave were performed. Shaded surface display (SSD) and virtual bronchoscopy (VB) for visualization of the bronchial segments was performed with ECG-gated and non-ECG-gated MDCT data. The visualization of the bronchial tree underwent blinded scoring. Effective radiation dose and signal-to-noise ratio (SNR) for both techniques were compared. Results: There was no significant difference in visualizing single bronchial segments using ECG-gated compared to non-ECG-gated MDCT data. However, the total sum of scores for all bronchial segments visualized with non-ECG-gated MDCT was significantly higher compared to ECG-gated MDCT (P [de

Gate errors in solid-state quantum-computer architectures

International Nuclear Information System (INIS)

Hu Xuedong; Das Sarma, S.

2002-01-01

We theoretically consider possible errors in solid-state quantum computation due to the interplay of the complex solid-state environment and gate imperfections. In particular, we study two examples of gate operations in the opposite ends of the gate speed spectrum, an adiabatic gate operation in electron-spin-based quantum dot quantum computation and a sudden gate operation in Cooper-pair-box superconducting quantum computation. We evaluate quantitatively the nonadiabatic operation of a two-qubit gate in a two-electron double quantum dot. We also analyze the nonsudden pulse gate in a Cooper-pair-box-based quantum-computer model. In both cases our numerical results show strong influences of the higher excited states of the system on the gate operation, clearly demonstrating the importance of a detailed understanding of the relevant Hilbert-space structure on the quantum-computer operations

Edge-on gating effect in molecular wires.

Science.gov (United States)

Lo, Wai-Yip; Bi, Wuguo; Li, Lianwei; Jung, In Hwan; Yu, Luping

2015-02-11

This work demonstrates edge-on chemical gating effect in molecular wires utilizing the pyridinoparacyclophane (PC) moiety as the gate. Different substituents with varied electronic demands are attached to the gate to simulate the effect of varying gating voltages similar to that in field-effect transistor (FET). It was observed that the orbital energy level and charge carrier's tunneling barriers can be tuned by changing the gating group from strong electron acceptors to strong electron donors. The single molecule conductance and current-voltage characteristics of this molecular system are truly similar to those expected for an actual single molecular transistor.

Comparison of gate dielectric plasma damage from plasma-enhanced atomic layer deposited and magnetron sputtered TiN metal gates

Energy Technology Data Exchange (ETDEWEB)

Brennan, Christopher J.; Neumann, Christopher M.; Vitale, Steven A., E-mail: steven.vitale@ll.mit.edu [Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02420 (United States)

2015-07-28

Fully depleted silicon-on-insulator transistors were fabricated using two different metal gate deposition mechanisms to compare plasma damage effects on gate oxide quality. Devices fabricated with both plasma-enhanced atomic-layer-deposited (PE-ALD) TiN gates and magnetron plasma sputtered TiN gates showed very good electrostatics and short-channel characteristics. However, the gate oxide quality was markedly better for PE-ALD TiN. A significant reduction in interface state density was inferred from capacitance-voltage measurements as well as a 1200× reduction in gate leakage current. A high-power magnetron plasma source produces a much higher energetic ion and vacuum ultra-violet (VUV) photon flux to the wafer compared to a low-power inductively coupled PE-ALD source. The ion and VUV photons produce defect states in the bulk of the gate oxide as well as at the oxide-silicon interface, causing higher leakage and potential reliability degradation.

Opening of the New Gate E - Final Closure of Gate C - New azur «B» type cern access card

CERN Multimedia

Relations with the Host States Service

2004-01-01

Gate E ("Charles de Gaulle Gate") to the Meyrin Site will be open, for those entitled to use it, from 1 November 2004. The opening of this Gate should contribute to relieving congestion not only on the Prévessin - RN84 and Meyrin Route border crossings but also at Gates A and B. As a result, Gate C will be closed indefinitely from 1 November 2004. Providing a direct link between the Meyrin Site and the French territory beyond the fenced part of the CERN site, Gate E is the subject of international agreements between CERN, Switzerland and France, on the basis of which the Director-General has issued the "Rules for the Use of Gate E", (document CERN/DSU-RH/12222 of 27 October 2004; see also the latest news in "publications" at http://www.cern.ch/relations/). The main provisions of these Rules are as follows: Gate E is open from Monday to Friday, except on official CERN holidays, from 7.30 a.m. to 9.30 a.m. for access into the site, and from 4.30 p.m. to 6.30 p.m. for passage out of the site. Persons are aut...

Gate length variation effect on performance of gate-first self-aligned In₀.₅₃Ga₀.₄₇As MOSFET.

Science.gov (United States)

Mohd Razip Wee, Mohd F; Dehzangi, Arash; Bollaert, Sylvain; Wichmann, Nicolas; Majlis, Burhanuddin Y

2013-01-01

A multi-gate n-type In₀.₅₃Ga₀.₄₇As MOSFET is fabricated using gate-first self-aligned method and air-bridge technology. The devices with different gate lengths were fabricated with the Al2O3 oxide layer with the thickness of 8 nm. In this letter, impact of gate length variation on device parameter such as threshold voltage, high and low voltage transconductance, subthreshold swing and off current are investigated at room temperature. Scaling the gate length revealed good enhancement in all investigated parameters but the negative shift in threshold voltage was observed for shorter gate lengths. The high drain current of 1.13 A/mm and maximum extrinsic transconductance of 678 mS/mm with the field effect mobility of 364 cm(2)/Vs are achieved for the gate length and width of 0.2 µm and 30 µm, respectively. The source/drain overlap length for the device is approximately extracted about 51 nm with the leakage current in order of 10(-8) A. The results of RF measurement for cut-off and maximum oscillation frequency for devices with different gate lengths are compared.

Gate Length Variation Effect on Performance of Gate-First Self-Aligned In0.53Ga0.47As MOSFET

Science.gov (United States)

Mohd Razip Wee, Mohd F.; Dehzangi, Arash; Bollaert, Sylvain; Wichmann, Nicolas; Majlis, Burhanuddin Y.

2013-01-01

A multi-gate n-type In0.53Ga0.47As MOSFET is fabricated using gate-first self-aligned method and air-bridge technology. The devices with different gate lengths were fabricated with the Al2O3 oxide layer with the thickness of 8 nm. In this letter, impact of gate length variation on device parameter such as threshold voltage, high and low voltage transconductance, subthreshold swing and off current are investigated at room temperature. Scaling the gate length revealed good enhancement in all investigated parameters but the negative shift in threshold voltage was observed for shorter gate lengths. The high drain current of 1.13 A/mm and maximum extrinsic transconductance of 678 mS/mm with the field effect mobility of 364 cm2/Vs are achieved for the gate length and width of 0.2 µm and 30µm, respectively. The source/drain overlap length for the device is approximately extracted about 51 nm with the leakage current in order of 10−8 A. The results of RF measurement for cut-off and maximum oscillation frequency for devices with different gate lengths are compared. PMID:24367548

Functional and pharmacological consequences of the distribution of voltage-gated calcium channels in the renal blood vessels

DEFF Research Database (Denmark)

Hansen, P B L

2013-01-01

Calcium channel blockers are widely used to treat hypertension because they inhibit voltage-gated calcium channels that mediate transmembrane calcium influx in, for example, vascular smooth muscle and cardiomyocytes. The calcium channel family consists of several subfamilies, of which the L......-type is usually associated with vascular contractility. However, the L-, T- and P-/Q-types of calcium channels are present in the renal vasculature and are differentially involved in controlling vascular contractility, thereby contributing to regulation of kidney function and blood pressure. In the preglomerular...... vascular bed, all the three channel families are present. However, the T-type channel is the only channel in cortical efferent arterioles which is in contrast to the juxtamedullary efferent arteriole, and that leads to diverse functional effects of L- and T-type channel inhibition. Furthermore...

Gate-first integration of tunable work function metal gates of different thicknesses into high-k metal gates CMOS FinFETs for multi- VTh engineering

KAUST Repository

Hussain, Muhammad Mustafa; Smith, Casey Eben; Harris, Harlan Rusty; Young, Chadwin; Tseng, Hsinghuang; Jammy, Rajarao

2010-01-01

Gate-first integration of tunable work function metal gates of different thicknesses (320 nm) into high-k/metal gates CMOS FinFETs was demonstrated to achieve multiple threshold voltages (VTh) for 32-nm technology and beyond logic, memory, input/output, and system-on-a-chip applications. The fabricated devices showed excellent short-channel effect immunity (drain-induced barrier lowering ∼ 40 mV/V), nearly symmetric VTh, low T inv(∼ 1.4 nm), and high Ion(∼780μAμm) for N/PMOS without any intentional strain enhancement. © 2006 IEEE.

Gate-first integration of tunable work function metal gates of different thicknesses into high-k metal gates CMOS FinFETs for multi- VTh engineering

KAUST Repository

Hussain, Muhammad Mustafa

2010-03-01

Gate-first integration of tunable work function metal gates of different thicknesses (320 nm) into high-k/metal gates CMOS FinFETs was demonstrated to achieve multiple threshold voltages (VTh) for 32-nm technology and beyond logic, memory, input/output, and system-on-a-chip applications. The fabricated devices showed excellent short-channel effect immunity (drain-induced barrier lowering ∼ 40 mV/V), nearly symmetric VTh, low T inv(∼ 1.4 nm), and high Ion(∼780μAμm) for N/PMOS without any intentional strain enhancement. © 2006 IEEE.

Only connect: the merger of BMC Pharmacology and BMC Clinical Pharmacology.

Science.gov (United States)

Moylan, Elizabeth C; Morrey, Christopher; Appleford-Cook, Joanne M

2012-08-13

This editorial celebrates the launch of BMC Pharmacology and Toxicology within the BMC series of journals published by BioMed Central. The scope of the journal is interdisciplinary encompassing toxicology, experimental and clinical pharmacology including clinical trials. In this editorial we discuss the origins of this new journal and the ethos and policies under which it will operate.

Pharmacologic Evaluation of Antidepressant Activity and Synthesis of 2-Morpholino-5-phenyl-6H-1,3,4-thiadiazine Hydrobromide

Directory of Open Access Journals (Sweden)

Alexey P. Sarapultsev

2016-05-01

Full Text Available Substituted thiadiazines exert a reliable therapeutic effect in treating stress, and a schematic description of their ability to influence all aspects of a stress response has been depicted. This study was conducted to pharmacologically evaluate compound L-17, a substituted thiadiazine, (2-morpholino-5-phenyl-6H-1,3,4-thiadiazine, hydrobromide for possible anti-psychotic/antidepressant activity. Compound L-17 was synthesized by cyclocondensation of α-bromoacetophenone with the original morpholine-4-carbothionic acid hydrazide. Pharmacologic evaluations were conducted using methods described by E.F. Lavretskaya (1985, and in accordance with published guidelines for studying drugs for neuroleptic activity. Compound L-17 was evaluated for various possible mechanisms of action, including its effects on cholinergic system agonists/antagonists, dopaminergic neurotransmission, the adrenergic system, and 5-HT3 serotonin receptors. One or more of these mechanisms may be responsible for the beneficial effects shown by thiadiazine compounds in experiments conducted to evaluate their activity in models of acute stress and acute myocardial infarction.

Protected gates for topological quantum field theories

International Nuclear Information System (INIS)

Beverland, Michael E.; Pastawski, Fernando; Preskill, John; Buerschaper, Oliver; Koenig, Robert; Sijher, Sumit

2016-01-01

We study restrictions on locality-preserving unitary logical gates for topological quantum codes in two spatial dimensions. A locality-preserving operation is one which maps local operators to local operators — for example, a constant-depth quantum circuit of geometrically local gates, or evolution for a constant time governed by a geometrically local bounded-strength Hamiltonian. Locality-preserving logical gates of topological codes are intrinsically fault tolerant because spatially localized errors remain localized, and hence sufficiently dilute errors remain correctable. By invoking general properties of two-dimensional topological field theories, we find that the locality-preserving logical gates are severely limited for codes which admit non-abelian anyons, in particular, there are no locality-preserving logical gates on the torus or the sphere with M punctures if the braiding of anyons is computationally universal. Furthermore, for Ising anyons on the M-punctured sphere, locality-preserving gates must be elements of the logical Pauli group. We derive these results by relating logical gates of a topological code to automorphisms of the Verlinde algebra of the corresponding anyon model, and by requiring the logical gates to be compatible with basis changes in the logical Hilbert space arising from local F-moves and the mapping class group

Latest design of gate valves

Energy Technology Data Exchange (ETDEWEB)

Kurzhofer, U.; Stolte, J.; Weyand, M.

1996-12-01

Babcock Sempell, one of the most important valve manufacturers in Europe, has delivered valves for the nuclear power industry since the beginning of the peaceful application of nuclear power in the 1960s. The latest innovation by Babcock Sempell is a gate valve that meets all recent technical requirements of the nuclear power technology. At the moment in the United States, Germany, Sweden, and many other countries, motor-operated gate and globe valves are judged very critically. Besides the absolute control of the so-called {open_quotes}trip failure,{close_quotes} the integrity of all valve parts submitted to operational forces must be maintained. In case of failure of the limit and torque switches, all valve designs have been tested with respect to the quality of guidance of the gate. The guidances (i.e., guides) shall avoid a tilting of the gate during the closing procedure. The gate valve newly designed by Babcock Sempell fulfills all these characteristic criteria. In addition, the valve has cobalt-free seat hardfacing, the suitability of which has been proven by friction tests as well as full-scale blowdown tests at the GAP of Siemens in Karlstein, West Germany. Babcock Sempell was to deliver more than 30 gate valves of this type for 5 Swedish nuclear power stations by autumn 1995. In the presentation, the author will report on the testing performed, qualifications, and sizing criteria which led to the new technical design.

Age- and gender-specific differences in left ventricular cardiac function and volumes determined by gated SPET

International Nuclear Information System (INIS)

Bondt, P. de; Wiele, C. van de; Winter, F. de; Dierckx, R.A.; Sutter, J. de; Backer, G. de

2001-01-01

The aim of this study was to determine normative volumetric data and ejection fraction values derived from gated myocardial single-photon emission tomography (SPET) using the commercially available software algorithm QGS (quantitative gated SPET). From a prospective database of 876 consecutive patients who were referred for a 2-day stress-rest technetium-99m tetrofosmin (925 MBq) gated SPET study, 102 patients (43 men, 59 women) with a low (<10%) pre-test likelihood of coronary disease were included (mean age 57.6 years). For stress imaging, a bicycle protocol was used in 79 of the patients and a dipyridamole protocol in 23. Left ventricular ejection fraction (LVEF) and end-diastolic and -systolic volumes (EDV and ESV) were calculated by QGS. EDV and ESV were corrected for body surface area, indicated by EDVi and ESVi. To allow comparison with previous reports using other imaging modalities, men and women were divided into three age groups (<45 years, ≥45 years but <65 years and ≥65 years). Men showed significantly higher EDVi and ESVi values throughout and lower LVEF values when compared with women in the subgroup ≥65 years (P<0.05, ANOVA). Significant negative and positive correlations were found between age and EDVi and ESVi values for both women and men and between LVEF and age in women (Pearson P≤0.01). LVEF values at bicycle stress were significantly higher than at rest (P=0.000, paired t test), which was the result of a significant decrease in ESV (P=0.003), a phenomenon which did not occur following dipyridamole stress (P=0.409). The data presented suggest that LVEF and EDVi and ESVi as assessed by QGS are strongly gender-specific. Although the physiological significance of these results is uncertain and needs further study, these findings demonstrate that the evaluation of cardiac function and volumes of patients by means of QGS should consider age- and gender-matched normative values. (orig.)

High-Fidelity Single-Shot Toffoli Gate via Quantum Control.

Science.gov (United States)

Zahedinejad, Ehsan; Ghosh, Joydip; Sanders, Barry C

2015-05-22

A single-shot Toffoli, or controlled-controlled-not, gate is desirable for classical and quantum information processing. The Toffoli gate alone is universal for reversible computing and, accompanied by the Hadamard gate, forms a universal gate set for quantum computing. The Toffoli gate is also a key ingredient for (nontopological) quantum error correction. Currently Toffoli gates are achieved by decomposing into sequentially implemented single- and two-qubit gates, which require much longer times and yields lower overall fidelities compared to a single-shot implementation. We develop a quantum-control procedure to construct a single-shot Toffoli gate for three nearest-neighbor-coupled superconducting transmon systems such that the fidelity is 99.9% and is as fast as an entangling two-qubit gate under the same realistic conditions. The gate is achieved by a nongreedy quantum control procedure using our enhanced version of the differential evolution algorithm.

Tunable pulse-shaping with gated graphene nanoribbons

DEFF Research Database (Denmark)

Prokopeva, Ludmila; Emani, Naresh K.; Boltasseva, Alexandra

2014-01-01

We propose a pulse-shaper made of gated graphene nanoribbons. Simulations demonstrate tunable control over the shapes of transmitted and reflected pulses using the gating bias. Initial fabrication and characterization of graphene elements is also discussed.......We propose a pulse-shaper made of gated graphene nanoribbons. Simulations demonstrate tunable control over the shapes of transmitted and reflected pulses using the gating bias. Initial fabrication and characterization of graphene elements is also discussed....

Pharmacological enhancement of exposure-based treatment in PTSD: a qualitative review

OpenAIRE

de Kleine, Rianne A.; Rothbaum, Barbara O.; van Minnen, Agnes

2013-01-01

There is a good amount of evidence that exposure therapy is an effective treatment for posttraumatic stress disorder (PTSD). Notwithstanding its efficacy, there is room for improvement, since a large proportion of patients does not benefit from treatment. Recently, an interesting new direction in the improvement of exposure therapy efficacy for PTSD emerged. Basic research found evidence of the pharmacological enhancement of the underlying learning and memory processes of exposure therapy. Th...

Structured-gate organic field-effect transistors

International Nuclear Information System (INIS)

Aljada, Muhsen; Pandey, Ajay K; Velusamy, Marappan; Burn, Paul L; Meredith, Paul; Namdas, Ebinazar B

2012-01-01

We report the fabrication and electrical characteristics of structured-gate organic field-effect transistors consisting of a gate electrode patterned with three-dimensional pillars. The pillar gate electrode was over-coated with a gate dielectric (SiO 2 ) and solution processed organic semiconductors producing both unipolar p-type and bipolar behaviour. We show that this new structured-gate architecture delivers higher source-drain currents, higher gate capacitance per unit equivalent linear channel area, and enhanced charge injection (electrons and/or holes) versus the conventional planar structure in all modes of operation. For the bipolar field-effect transistor (FET) the maximum source-drain current enhancements in p- and n-channel mode were >600% and 28%, respectively, leading to p and n charge mobilities with the same order of magnitude. Thus, we have demonstrated that it is possible to use the FET architecture to manipulate and match carrier mobilities of material combinations where one charge carrier is normally dominant. Mobility matching is advantageous for creating organic logic circuit elements such as inverters and amplifiers. Hence, the method represents a facile and generic strategy for improving the performance of standard organic semiconductors as well as new materials and blends. (paper)

Structured-gate organic field-effect transistors

Science.gov (United States)

Aljada, Muhsen; Pandey, Ajay K.; Velusamy, Marappan; Burn, Paul L.; Meredith, Paul; Namdas, Ebinazar B.

2012-06-01

We report the fabrication and electrical characteristics of structured-gate organic field-effect transistors consisting of a gate electrode patterned with three-dimensional pillars. The pillar gate electrode was over-coated with a gate dielectric (SiO2) and solution processed organic semiconductors producing both unipolar p-type and bipolar behaviour. We show that this new structured-gate architecture delivers higher source-drain currents, higher gate capacitance per unit equivalent linear channel area, and enhanced charge injection (electrons and/or holes) versus the conventional planar structure in all modes of operation. For the bipolar field-effect transistor (FET) the maximum source-drain current enhancements in p- and n-channel mode were >600% and 28%, respectively, leading to p and n charge mobilities with the same order of magnitude. Thus, we have demonstrated that it is possible to use the FET architecture to manipulate and match carrier mobilities of material combinations where one charge carrier is normally dominant. Mobility matching is advantageous for creating organic logic circuit elements such as inverters and amplifiers. Hence, the method represents a facile and generic strategy for improving the performance of standard organic semiconductors as well as new materials and blends.

Amplifying genetic logic gates.

Science.gov (United States)

Bonnet, Jerome; Yin, Peter; Ortiz, Monica E; Subsoontorn, Pakpoom; Endy, Drew

2013-05-03

Organisms must process information encoded via developmental and environmental signals to survive and reproduce. Researchers have also engineered synthetic genetic logic to realize simpler, independent control of biological processes. We developed a three-terminal device architecture, termed the transcriptor, that uses bacteriophage serine integrases to control the flow of RNA polymerase along DNA. Integrase-mediated inversion or deletion of DNA encoding transcription terminators or a promoter modulates transcription rates. We realized permanent amplifying AND, NAND, OR, XOR, NOR, and XNOR gates actuated across common control signal ranges and sequential logic supporting autonomous cell-cell communication of DNA encoding distinct logic-gate states. The single-layer digital logic architecture developed here enables engineering of amplifying logic gates to control transcription rates within and across diverse organisms.

Physical Modeling of Gate-Controlled Schottky Barrier Lowering of Metal-Graphene Contacts in Top-Gated Graphene Field-Effect Transistors

Science.gov (United States)

Mao, Ling-Feng; Ning, Huansheng; Huo, Zong-Liang; Wang, Jin-Yan

2015-12-01

A new physical model of the gate controlled Schottky barrier height (SBH) lowering in top-gated graphene field-effect transistors (GFETs) under saturation bias condition is proposed based on the energy conservation equation with the balance assumption. The theoretical prediction of the SBH lowering agrees well with the experimental data reported in literatures. The reduction of the SBH increases with the increasing of gate voltage and relative dielectric constant of the gate oxide, while it decreases with the increasing of oxide thickness, channel length and acceptor density. The magnitude of the reduction is slightly enhanced under high drain voltage. Moreover, it is found that the gate oxide materials with large relative dielectric constant (>20) have a significant effect on the gate controlled SBH lowering, implying that the energy relaxation of channel electrons should be taken into account for modeling SBH in GFETs.

Physical Modeling of Gate-Controlled Schottky Barrier Lowering of Metal-Graphene Contacts in Top-Gated Graphene Field-Effect Transistors.

Science.gov (United States)

Mao, Ling-Feng; Ning, Huansheng; Huo, Zong-Liang; Wang, Jin-Yan

2015-12-17

A new physical model of the gate controlled Schottky barrier height (SBH) lowering in top-gated graphene field-effect transistors (GFETs) under saturation bias condition is proposed based on the energy conservation equation with the balance assumption. The theoretical prediction of the SBH lowering agrees well with the experimental data reported in literatures. The reduction of the SBH increases with the increasing of gate voltage and relative dielectric constant of the gate oxide, while it decreases with the increasing of oxide thickness, channel length and acceptor density. The magnitude of the reduction is slightly enhanced under high drain voltage. Moreover, it is found that the gate oxide materials with large relative dielectric constant (>20) have a significant effect on the gate controlled SBH lowering, implying that the energy relaxation of channel electrons should be taken into account for modeling SBH in GFETs.

Pharmacological Conversion of a Cardiac Inward Rectifier into an Outward Rectifier Potassium Channel.

Science.gov (United States)

Moreno-Galindo, Eloy G; Sanchez-Chapula, Jose A; Tristani-Firouzi, Martin; Navarro-Polanco, Ricardo A

2016-09-01

Potassium (K(+)) channels are crucial for determining the shape, duration, and frequency of action-potential firing in excitable cells. Broadly speaking, K(+) channels can be classified based on whether their macroscopic current outwardly or inwardly rectifies, whereby rectification refers to a change in conductance with voltage. Outwardly rectifying K(+) channels conduct greater current at depolarized membrane potentials, whereas inward rectifier channels conduct greater current at hyperpolarized membrane potentials. Under most circumstances, outward currents through inwardly rectifying K(+) channels are reduced at more depolarized potentials. However, the acetylcholine-gated K(+) channel (KACh) conducts current that inwardly rectifies when activated by some ligands (such as acetylcholine), and yet conducts current that outwardly rectifies when activated by other ligands (for example, pilocarpine and choline). The perplexing and paradoxical behavior of KACh channels is due to the intrinsic voltage sensitivity of the receptor that activates KACh channels, the M2 muscarinic receptor (M2R). Emerging evidence reveals that the affinity of M2R for distinct ligands varies in a voltage-dependent and ligand-specific manner. These intrinsic receptor properties determine whether current conducted by KACh channels inwardly or outwardly rectifies. This review summarizes the most recent concepts regarding the intrinsic voltage sensitivity of muscarinic receptors and the consequences of this intriguing behavior on cardiac physiology and pharmacology of KACh channels. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Study of heat treatment parameters for large-scale hydraulic steel gate track

Directory of Open Access Journals (Sweden)

Ping-zhou Cao

2013-10-01

Full Text Available In order to enhance external hardness and strength, a large-scale hydraulic gate track should go through heat treatment. The current design method of hydraulic gate wheels and tracks is based on Hertz contact linear elastic theory, and does not take into account the changes in mechanical properties of materials caused by heat treatment. In this study, the heat treatment parameters were designed and analyzed according to the bearing mechanisms of the wheel and track. The quenching process of the track was simulated by the ANSYS program, and the temperature variation, residual stress, and deformation were obtained and analyzed. The metallurgical structure field after heat treatment was predicted by the method based on time-temperature-transformation (TTT curves. The results show that the analysis method and designed track heat treatment process are feasible, and can provide a reference for practical projects.

Atomic-Layer-Deposited SnO2 as Gate Electrode for Indium-Free Transparent Electronics

KAUST Repository

Alshammari, Fwzah Hamud

2017-08-04

Atomic-layer-deposited SnO2 is used as a gate electrode to replace indium tin oxide (ITO) in thin-film transistors and circuits for the first time. The SnO2 films deposited at 200 °C show low electrical resistivity of ≈3.1 × 10−3 Ω cm with ≈93% transparency in most of the visible range of the electromagnetic spectrum. Thin-film transistors fabricated with SnO2 gates show excellent transistor properties including saturation mobility of 15.3 cm2 V−1 s−1, a low subthreshold swing of ≈130 mV dec−1, a high on/off ratio of ≈109, and an excellent electrical stability under constant-voltage stressing conditions to the gate terminal. Moreover, the SnO2-gated thin-film transistors show excellent electrical characteristics when used in electronic circuits such as negative channel metal oxide semiconductor (NMOS) inverters and ring oscillators. The NMOS inverters exhibit a low propagation stage delay of ≈150 ns with high DC voltage gain of ≈382. A high oscillation frequency of ≈303 kHz is obtained from the output sinusoidal signal of the 11-stage NMOS inverter-based ring oscillators. These results show that SnO2 can effectively replace ITO in transparent electronics and sensor applications.

A bistable electromagnetically actuated rotary gate microvalve

International Nuclear Information System (INIS)

Luharuka, Rajesh; Hesketh, Peter J

2008-01-01

Two types of rotary gate microvalves are developed for flow modulation in microfluidic systems. These microvalves have been tested for an open flow rate of up to 100 sccm and operate under a differential pressure of 6 psig with flow modulation of up to 100. The microvalve consists of a suspended gate that rotates in the plane of the chip to regulate flow through the orifice. The gate is suspended by a novel fully compliant in-plane rotary bistable micromechanism (IPRBM) that advantageously constrains the gate in all degrees of freedom except for in-plane rotational motion. Multiple inlet/outlet orifices provide flexibility of operating the microvalve in three different flow configurations. The rotary gate microvalve is switched with an external electromagnetic actuator. The suspended gate is made of a soft magnetic material and its electromagnetic actuation is based on the operating principle of a variable-reluctance stepper motor

Impact of psychological stress on irritable bowel syndrome.

Science.gov (United States)

Qin, Hong-Yan; Cheng, Chung-Wah; Tang, Xu-Dong; Bian, Zhao-Xiang

2014-10-21

Psychological stress is an important factor for the development of irritable bowel syndrome (IBS). More and more clinical and experimental evidence showed that IBS is a combination of irritable bowel and irritable brain. In the present review we discuss the potential role of psychological stress in the pathogenesis of IBS and provide comprehensive approaches in clinical treatment. Evidence from clinical and experimental studies showed that psychological stresses have marked impact on intestinal sensitivity, motility, secretion and permeability, and the underlying mechanism has a close correlation with mucosal immune activation, alterations in central nervous system, peripheral neurons and gastrointestinal microbiota. Stress-induced alterations in neuro-endocrine-immune pathways acts on the gut-brain axis and microbiota-gut-brain axis, and cause symptom flare-ups or exaggeration in IBS. IBS is a stress-sensitive disorder, therefore, the treatment of IBS should focus on managing stress and stress-induced responses. Now, non-pharmacological approaches and pharmacological strategies that target on stress-related alterations, such as antidepressants, antipsychotics, miscellaneous agents, 5-HT synthesis inhibitors, selective 5-HT reuptake inhibitors, and specific 5-HT receptor antagonists or agonists have shown a critical role in IBS management. A integrative approach for IBS management is a necessary.

Phase analysis of gated blood pool SPECT for multiple stress testing assessments of ventricular mechanical dyssynchrony in a tachycardia-induced dilated cardiomyopathy canine model.

Science.gov (United States)

Salimian, Samaneh; Thibault, Bernard; Finnerty, Vincent; Grégoire, Jean; Harel, François

2017-02-01

Stress-induced dyssynchrony has been shown to be independently correlated with clinical outcomes in patients with dilated cardiomyopathy (DCM) and narrow QRS complexes. However, the extent to which stress levels affect inter- and intraventricular dyssynchrony parameters remains unknown. Ten large dogs were submitted to tachycardia-induced DCM by pacing the right ventricular apex for 3-4 weeks to reach a target ejection fraction (EF) of 35% or less. Stress was then induced in DCM dogs by administering intravenous dobutamine up to a maximum of 20 μg·kg -1 ·min -1 . Hemodynamic and ventricular dyssynchrony data were analyzed by left ventricular (LV) pressure measurements and gated blood pool SPECT (GBPS) imaging. In order to assess mechanical dyssynchrony in DCM subjects and compare it with that of 8 normal counterparts, we extracted the following data: count-based indices of LV contraction homogeneity index (CHI), entropy and phase standard deviation, and interventricular dyssynchrony index. A significant LV intraventricular dyssynchrony (CHI: 96.4 ± 1.3% in control vs 78.6% ± 10.9% in DCM subjects) resulted in an intense LV dysfunction in DCM subjects (EF: 49.5% ± 8.4% in control vs 22.6% ± 6.0% in DCM), compared to control subjects. However, interventricular dyssynchrony did not vary significantly between the two groups. Under stress, DCM subjects showed a significant improvement in ventricular functional parameters at each level (EF: 22.6% ± 6.0% at rest vs 48.1% ± 5.8% at maximum stress). All intraventricular dyssynchrony indices showed a significant increase in magnitude of synchrony from baseline to stress levels of greater than or equal to 5 μg·kg -1 ·min -1 dobutamine. There were individual differences in the magnitude and pattern of change in interventricular dyssynchrony during the various levels of stress. Based on GBPS analyses, different levels of functional stress, even in close intervals, can have a significant impact on

Piezoconductivity of gated suspended graphene

NARCIS (Netherlands)

Medvedyeva, M.V.; Blanter, Y.M.

2011-01-01

We investigate the conductivity of graphene sheet deformed over a gate. The effect of the deformation on the conductivity is twofold: The lattice distortion can be represented as pseudovector potential in the Dirac equation formalism, whereas the gate causes inhomogeneous density redistribution. We

Restless Tuneup of High-Fidelity Qubit Gates

Science.gov (United States)

Rol, M. A.; Bultink, C. C.; O'Brien, T. E.; de Jong, S. R.; Theis, L. S.; Fu, X.; Luthi, F.; Vermeulen, R. F. L.; de Sterke, J. C.; Bruno, A.; Deurloo, D.; Schouten, R. N.; Wilhelm, F. K.; DiCarlo, L.

2017-04-01

We present a tuneup protocol for qubit gates with tenfold speedup over traditional methods reliant on qubit initialization by energy relaxation. This speedup is achieved by constructing a cost function for Nelder-Mead optimization from real-time correlation of nondemolition measurements interleaving gate operations without pause. Applying the protocol on a transmon qubit achieves 0.999 average Clifford fidelity in one minute, as independently verified using randomized benchmarking and gate-set tomography. The adjustable sensitivity of the cost function allows the detection of fractional changes in the gate error with a nearly constant signal-to-noise ratio. The restless concept demonstrated can be readily extended to the tuneup of two-qubit gates and measurement operations.

Pharmacologic intervention as an alternative to exercise stress

International Nuclear Information System (INIS)

Gould, K.L.

1987-01-01

Although thallium exercise imaging has served an important role in clinical cardiology, it is significantly limited by suboptimal sensitivity and specificity, particularly in asymptomatic man. The increasing recognition of silent myocardial ischemia, the significant prevalence of coronary artery disease in asymptomatic middle age men, and the frequent occurrence of myocardial infarction without preceding symptoms in 60% of cases emphasizes the need for a more definitive, noninvasive diagnostic test for the presence of coronary artery disease suitable for screening in asymptomatic or symptomatic patients. Intravenous dipyridamole combined with handgrip stress provides a potent stimulus for purposes of diagnostic perfusion imaging. Although planar and single photon emission computed tomography (SPECT) imaging also have played an important role, these techniques are seriously hindered by their inability to quantitate radiotracer uptake or image modest differences in maximum relative flow caused by coronary artery stenosis. Accordingly, the combination of dipyridamole-handgrip stress with positron imaging of myocardial perfusion has become a powerful diagnostic tool suitable for routine clinical use. With the availability of generator-produced rubidium-82, dedicated clinically oriented positron cameras, the routine application of positron imaging to clinical cardiology has become feasible. 75 references

Pharmacologic Approach to Defective Protein Trafficking in the E637K-hERG Mutant with PD-118057 and Thapsigargin.

Directory of Open Access Journals (Sweden)

Haiyan Mao

Full Text Available Treatment of LQT2 is inadequate. Many drugs which can pharmacologically rescue defective protein trafficking in LQT2 also result in potent blockade of HERG current, negating their therapeutic benefit. It is reported that PD-118057 and thapsigargin can rescue LQT2 without hERG channel blockade, but the precise mechanism of action is unknown. Furthermore, the effect of PD-118057 and thapsigargin on the dominant negative E637K-hERG mutant has not been previously investigated.IN THIS STUDY, WE INVESTIGATED: (a the effect of PD-118057 and thapsigargin on the current amplitudes of WT-hERG and WT/E637K-hERG channels; (b the effect of PD-118057 and thapsigargin on the biophysical properties of WT-hERG and WT/E637K-hERG channels; (c whether drug treatment can rescue channel processing and trafficking defects of the WT/E637K-hERG mutant.The whole-cell Patch-clamp technique was used to assess the effect of PD-118057 and thapsigargin on the electrophysiological characteristics of the rapidly activating delayed rectifier K(+ current (Ikr of the hERG protein channel. Western blot was done to investigate pharmacological rescue on hERG protein channel function.In our study, PD-118057 was shown to significantly enhance both the maximum current amplitude and tail current amplitude, but did not alter the gating and kinetic properties of the WT-hERG channel, with the exception of accelerating steady-state inactivation. Additionally, thapsigargin shows a similar result as PD-118057 for the WT-hERG channel, but with the exception of attenuating steady-state inactivation. However, for the WT/E637K-hERG channel, PD-118057 had no effect on either the current or on the gating and kinetic properties. Furthermore, thapsigargin treatment did not alter the current or the gating and kinetic properties of the WT/E637K-hERG channel, with the exception of opening at more positive voltages.Our findings illustrate that neither PD-118057 nor thapsigargin play a role in correcting

Top-gate hybrid complementary inverters using pentacene and amorphous InGaZnO thin-film transistors with high operational stability

Directory of Open Access Journals (Sweden)

J. B. Kim

2012-03-01

Full Text Available We report on the operational stability of low-voltage hybrid organic-inorganic complementary inverters with a top-gate bottom source-drain geometry. The inverters are comprised of p-channel pentacene and n-channel amorphous InGaZnO thin-film transistors (TFTs with bi-layer gate dielectrics formed from an amorphous layer of a fluoropolymer (CYTOP and a high-k layer of Al2O3. The p- and n- channel TFTs show saturation mobility values of 0.1 ± 0.01 and 5.0 ± 0.5 cm2/Vs, respectively. The individual transistors show high electrical stability with less than 6% drain-to-source current variations after 1 h direct current (DC bias stress. Complementary inverters yield hysteresis-free voltage transfer characteristics for forward and reverse input biases with static DC gain values larger than 45 V/V at 8 V before and after being subjected to different conditions of electrical stress. Small and reversible variations of the switching threshold voltage of the inverters during these stress tests are compatible with the observed stability of the individual TFTs.

Mining the Virgin Land of Neurotoxicology: A Novel Paradigm of Neurotoxic Peptides Action on Glycosylated Voltage-Gated Sodium Channels

Directory of Open Access Journals (Sweden)

Zhirui Liu

2012-01-01

Full Text Available Voltage-gated sodium channels (VGSCs are important membrane protein carrying on the molecular basis for action potentials (AP in neuronal firings. Even though the structure-function studies were the most pursued spots, the posttranslation modification processes, such as glycosylation, phosphorylation, and alternative splicing associating with channel functions captured less eyesights. The accumulative research suggested an interaction between the sialic acids chains and ion-permeable pores, giving rise to subtle but significant impacts on channel gating. Sodium channel-specific neurotoxic toxins, a family of long-chain polypeptides originated from venomous animals, are found to potentially share the binding sites adjacent to glycosylated region on VGSCs. Thus, an interaction between toxin and glycosylated VGSC might hopefully join the campaign to approach the role of glycosylation in modulating VGSCs-involved neuronal network activity. This paper will cover the state-of-the-art advances of researches on glycosylation-mediated VGSCs function and the possible underlying mechanisms of interactions between toxin and glycosylated VGSCs, which may therefore, fulfill the knowledge in identifying the pharmacological targets and therapeutic values of VGSCs.

Light-effect transistor (LET with multiple independent gating controls for optical logic gates and optical amplification

Directory of Open Access Journals (Sweden)

Jason eMarmon

2016-03-01

Full Text Available Modern electronics are developing electronic-optical integrated circuits, while their electronic backbone, e.g. field-effect transistors (FETs, remains the same. However, further FET down scaling is facing physical and technical challenges. A light-effect transistor (LET offers electronic-optical hybridization at the component level, which can continue Moore’s law to quantum region without requiring a FET’s fabrication complexity, e.g. physical gate and doping, by employing optical gating and photoconductivity. Multiple independent gates are therefore readily realized to achieve unique functionalities without increasing chip space. Here we report LET device characteristics and novel digital and analog applications, such as optical logic gates and optical amplification. Prototype CdSe-nanowire-based LETs show output and transfer characteristics resembling advanced FETs, e.g. on/off ratios up to ~1.0x106 with a source-drain voltage of ~1.43 V, gate-power of ~260 nW, and subthreshold swing of ~0.3 nW/decade (excluding losses. Our work offers new electronic-optical integration strategies and electronic and optical computing approaches.

Implementation of a two-qubit controlled-rotation gate based on unconventional geometric phase with a constant gating time

International Nuclear Information System (INIS)

Yabu-uti, B.F.C.; Roversi, J.A.

2011-01-01

We propose an alternative scheme to implement a two-qubit controlled-R (rotation) gate in the hybrid atom-CCA (coupled cavities array) system. Our scheme results in a constant gating time and, with an adjustable qubit-bus coupling (atom-resonator), one can specify a particular rotation R on the target qubit. We believe that this proposal may open promising perspectives for networking quantum information processors and implementing distributed and scalable quantum computation. -- Highlights: → We propose an alternative two-qubit controlled-rotation gate implementation. → Our gate is realized in a constant gating time for any rotation. → A particular rotation on the target qubit can be specified by an adjustable qubit-bus coupling. → Our proposal may open promising perspectives for implementing distributed and scalable quantum computation.

Dual-gated volumetric modulated arc therapy

International Nuclear Information System (INIS)

Fahimian, Benjamin; Wu, Junqing; Wu, Huanmei; Geneser, Sarah; Xing, Lei

2014-01-01

Gated Volumetric Modulated Arc Therapy (VMAT) is an emerging radiation therapy modality for treatment of tumors affected by respiratory motion. However, gating significantly prolongs the treatment time, as delivery is only activated during a single respiratory phase. To enhance the efficiency of gated VMAT delivery, a novel dual-gated VMAT (DG-VMAT) technique, in which delivery is executed at both exhale and inhale phases in a given arc rotation, is developed and experimentally evaluated. Arc delivery at two phases is realized by sequentially interleaving control points consisting of MUs, MLC sequences, and angles of VMAT plans generated at the exhale and inhale phases. Dual-gated delivery is initiated when a respiration gating signal enters the exhale window; when the exhale delivery concludes, the beam turns off and the gantry rolls back to the starting position for the inhale window. The process is then repeated until both inhale and exhale arcs are fully delivered. DG-VMAT plan delivery accuracy was assessed using a pinpoint chamber and diode array phantom undergoing programmed motion. DG-VMAT delivery was experimentally implemented through custom XML scripting in Varian’s TrueBeam™ STx Developer Mode. Relative to single gated delivery at exhale, the treatment time was improved by 95.5% for a sinusoidal breathing pattern. The pinpoint chamber dose measurement agreed with the calculated dose within 0.7%. For the DG-VMAT delivery, 97.5% of the diode array measurements passed the 3%/3 mm gamma criterion. The feasibility of DG-VMAT delivery scheme has been experimentally demonstrated for the first time. By leveraging the stability and natural pauses that occur at end-inspiration and end-exhalation, DG-VMAT provides a practical method for enhancing gated delivery efficiency by up to a factor of two

Cognitive mechanisms associated with auditory sensory gating

Science.gov (United States)

Jones, L.A.; Hills, P.J.; Dick, K.M.; Jones, S.P.; Bright, P.

2016-01-01

Sensory gating is a neurophysiological measure of inhibition that is characterised by a reduction in the P50 event-related potential to a repeated identical stimulus. The objective of this work was to determine the cognitive mechanisms that relate to the neurological phenomenon of auditory sensory gating. Sixty participants underwent a battery of 10 cognitive tasks, including qualitatively different measures of attentional inhibition, working memory, and fluid intelligence. Participants additionally completed a paired-stimulus paradigm as a measure of auditory sensory gating. A correlational analysis revealed that several tasks correlated significantly with sensory gating. However once fluid intelligence and working memory were accounted for, only a measure of latent inhibition and accuracy scores on the continuous performance task showed significant sensitivity to sensory gating. We conclude that sensory gating reflects the identification of goal-irrelevant information at the encoding (input) stage and the subsequent ability to selectively attend to goal-relevant information based on that previous identification. PMID:26716891

Experimental superposition of orders of quantum gates

Science.gov (United States)

Procopio, Lorenzo M.; Moqanaki, Amir; Araújo, Mateus; Costa, Fabio; Alonso Calafell, Irati; Dowd, Emma G.; Hamel, Deny R.; Rozema, Lee A.; Brukner, Časlav; Walther, Philip

2015-01-01

Quantum computers achieve a speed-up by placing quantum bits (qubits) in superpositions of different states. However, it has recently been appreciated that quantum mechanics also allows one to ‘superimpose different operations'. Furthermore, it has been shown that using a qubit to coherently control the gate order allows one to accomplish a task—determining if two gates commute or anti-commute—with fewer gate uses than any known quantum algorithm. Here we experimentally demonstrate this advantage, in a photonic context, using a second qubit to control the order in which two gates are applied to a first qubit. We create the required superposition of gate orders by using additional degrees of freedom of the photons encoding our qubits. The new resource we exploit can be interpreted as a superposition of causal orders, and could allow quantum algorithms to be implemented with an efficiency unlikely to be achieved on a fixed-gate-order quantum computer. PMID:26250107

Getting started with FortiGate

CERN Document Server

Fabbri, Rosato

2013-01-01

This book is a step-by-step tutorial that will teach you everything you need to know about the deployment and management of FortiGate, including high availability, complex routing, various kinds of VPN working, user authentication, security rules and controls on applications, and mail and Internet access.This book is intended for network administrators, security managers, and IT pros. It is a great starting point if you have to administer or configure a FortiGate unit, especially if you have no previous experience. For people that have never managed a FortiGate unit, the book helpfully walks t

Methodology for Analysis, Modeling and Simulation of Airport Gate-waiting Delays

Science.gov (United States)

Wang, Jianfeng

This dissertation presents methodologies to estimate gate-waiting delays from historical data, to identify gate-waiting-delay functional causes in major U.S. airports, and to evaluate the impact of gate operation disruptions and mitigation strategies on gate-waiting delay. Airport gates are a resource of congestion in the air transportation system. When an arriving flight cannot pull into its gate, the delay it experiences is called gate-waiting delay. Some possible reasons for gate-waiting delay are: the gate is occupied, gate staff or equipment is unavailable, the weather prevents the use of the gate (e.g. lightning), or the airline has a preferred gate assignment. Gate-waiting delays potentially stay with the aircraft throughout the day (unless they are absorbed), adding costs to passengers and the airlines. As the volume of flights increases, ensuring that airport gates do not become a choke point of the system is critical. The first part of the dissertation presents a methodology for estimating gate-waiting delays based on historical, publicly available sources. Analysis of gate-waiting delays at major U.S. airports in the summer of 2007 identifies the following. (i) Gate-waiting delay is not a significant problem on majority of days; however, the worst delay days (e.g. 4% of the days at LGA) are extreme outliers. (ii) The Atlanta International Airport (ATL), the John F. Kennedy International Airport (JFK), the Dallas/Fort Worth International Airport (DFW) and the Philadelphia International Airport (PHL) experience the highest gate-waiting delays among major U.S. airports. (iii) There is a significant gate-waiting-delay difference between airlines due to a disproportional gate allocation. (iv) Gate-waiting delay is sensitive to time of a day and schedule peaks. According to basic principles of queueing theory, gate-waiting delay can be attributed to over-scheduling, higher-than-scheduled arrival rate, longer-than-scheduled gate-occupancy time, and reduced gate

Gate tunneling current and quantum capacitance in metal-oxide-semiconductor devices with graphene gate electrodes

Science.gov (United States)

An, Yanbin; Shekhawat, Aniruddh; Behnam, Ashkan; Pop, Eric; Ural, Ant

2016-11-01

Metal-oxide-semiconductor (MOS) devices with graphene as the metal gate electrode, silicon dioxide with thicknesses ranging from 5 to 20 nm as the dielectric, and p-type silicon as the semiconductor are fabricated and characterized. It is found that Fowler-Nordheim (F-N) tunneling dominates the gate tunneling current in these devices for oxide thicknesses of 10 nm and larger, whereas for devices with 5 nm oxide, direct tunneling starts to play a role in determining the total gate current. Furthermore, the temperature dependences of the F-N tunneling current for the 10 nm devices are characterized in the temperature range 77-300 K. The F-N coefficients and the effective tunneling barrier height are extracted as a function of temperature. It is found that the effective barrier height decreases with increasing temperature, which is in agreement with the results previously reported for conventional MOS devices with polysilicon or metal gate electrodes. In addition, high frequency capacitance-voltage measurements of these MOS devices are performed, which depict a local capacitance minimum under accumulation for thin oxides. By analyzing the data using numerical calculations based on the modified density of states of graphene in the presence of charged impurities, it is shown that this local minimum is due to the contribution of the quantum capacitance of graphene. Finally, the workfunction of the graphene gate electrode is extracted by determining the flat-band voltage as a function of oxide thickness. These results show that graphene is a promising candidate as the gate electrode in metal-oxide-semiconductor devices.

Precise linear gating circuit on integrated microcircuits

Energy Technology Data Exchange (ETDEWEB)

Butskii, V.V.; Vetokhin, S.S.; Reznikov, I.V.

Precise linear gating circuit on four microcircuits is described. A basic flowsheet of the gating circuit is given. The gating circuit consists of two input differential cascades total load of which is two current followers possessing low input and high output resistances. Follower outlets are connected to high ohmic dynamic load formed with a current source which permits to get high amplification (>1000) at one cascade. Nonlinearity amounts to <0.1% in the range of input signal amplitudes of -10-+10 V. Front duration for an output signal with 10 V amplitude amounts to 100 ns. Attenuation of input signal with a closed gating circuit is 60 db. The gating circuits described is used in the device intended for processing of scintillation sensor signals.

Bubble gate for in-plane flow control.

Science.gov (United States)

Oskooei, Ali; Abolhasani, Milad; Günther, Axel

2013-07-07

We introduce a miniature gate valve as a readily implementable strategy for actively controlling the flow of liquids on-chip, within a footprint of less than one square millimetre. Bubble gates provide for simple, consistent and scalable control of liquid flow in microchannel networks, are compatible with different bulk microfabrication processes and substrate materials, and require neither electrodes nor moving parts. A bubble gate consists of two microchannel sections: a liquid-filled channel and a gas channel that intercepts the liquid channel to form a T-junction. The open or closed state of a bubble gate is determined by selecting between two distinct gas pressure levels: the lower level corresponds to the "open" state while the higher level corresponds to the "closed" state. During closure, a gas bubble penetrates from the gas channel into the liquid, flanked by a column of equidistantly spaced micropillars on each side, until the flow of liquid is completely obstructed. We fabricated bubble gates using single-layer soft lithographic and bulk silicon micromachining procedures and evaluated their performance with a combination of theory and experimentation. We assessed the dynamic behaviour during more than 300 open-and-close cycles and report the operating pressure envelope for different bubble gate configurations and for the working fluids: de-ionized water, ethanol and a biological buffer. We obtained excellent agreement between the experimentally determined bubble gate operational envelope and a theoretical prediction based on static wetting behaviour. We report case studies that serve to illustrate the utility of bubble gates for liquid sampling in single and multi-layer microfluidic devices. Scalability of our strategy was demonstrated by simultaneously addressing 128 bubble gates.

Suppression of surface-originated gate lag by a dual-channel AlN/GaN high electron mobility transistor architecture

Science.gov (United States)

Deen, David A.; Storm, David F.; Scott Katzer, D.; Bass, R.; Meyer, David J.

2016-08-01

A dual-channel AlN/GaN high electron mobility transistor (HEMT) architecture is demonstrated that leverages ultra-thin epitaxial layers to suppress surface-related gate lag. Two high-density two-dimensional electron gas (2DEG) channels are utilized in an AlN/GaN/AlN/GaN heterostructure wherein the top 2DEG serves as a quasi-equipotential that screens potential fluctuations resulting from distributed surface and interface states. The bottom channel serves as the transistor's modulated channel. Dual-channel AlN/GaN heterostructures were grown by molecular beam epitaxy on free-standing hydride vapor phase epitaxy GaN substrates. HEMTs fabricated with 300 nm long recessed gates demonstrated a gate lag ratio (GLR) of 0.88 with no degradation in drain current after bias stressed in subthreshold. These structures additionally achieved small signal metrics ft/fmax of 27/46 GHz. These performance results are contrasted with the non-recessed gate dual-channel HEMT with a GLR of 0.74 and 82 mA/mm current collapse with ft/fmax of 48/60 GHz.

High speed gated x-ray imagers

International Nuclear Information System (INIS)

Kilkenny, J.D.; Bell, P.; Hanks, R.; Power, G.; Turner, R.E.; Wiedwald, J.

1988-01-01

Single and multi-frame gated x-ray images with time-resolution as fast as 150 psec are described. These systems are based on the gating of microchannel plates in a stripline configuration. The gating voltage comes from the avalanche breakdown of reverse biased p-n junction producing high power voltage pulses as short as 70 psec. Results from single and four frame x-ray cameras used on Nova are described. 8 refs., 9 figs

Respiratory gating and multi field technique radiotherapy for esophageal cancer

International Nuclear Information System (INIS)

Ohta, Atsushi; Kaidu, Motoki; Tanabe, Satoshi

2017-01-01

To investigate the effects of a respiratory gating and multi field technique on the dose-volume histogram (DVH) in radiotherapy for esophageal cancer. Twenty patients who underwent four-dimensional computed tomography for esophageal cancer were included. We retrospectively created the four treatment plans for each patient, with or without the respiratory gating and multi field technique: No gating-2-field, No gating-4-field, Gating-2-field, and Gating-4-field plans. We compared the DVH parameters of the lung and heart in the No gating-2-field plan with the other three plans.Result In the comparison of the parameters in the No gating-2-field plan, there are significant differences in the Lung V 5Gy , V 20Gy , mean dose with all three plans and the Heart V 25Gy -V 40Gy with Gating-2-field plan, V 35Gy , V 40Gy , mean dose with No Gating-4-field plan and V 30Gy -V 40Gy , and mean dose with Gating-4-field plan. The lung parameters were smaller in the Gating-2-field plan and larger in the No gating-4-field and Gating-4-field plans. The heart parameters were all larger in the No gating-2-field plan. The lung parameters were reduced by the respiratory gating technique and increased by the multi field technique. The heart parameters were reduced by both techniques. It is important to select the optimal technique according to the risk of complications. (author)

Can fear extinction be enhanced? A review of pharmacological and behavioral findings

Science.gov (United States)

Fitzgerald, Paul J.; Seemann, Jocelyn R.; Maren, Stephen

2014-01-01

There is considerable interest, from both a basic and clinical standpoint, in gaining a greater understanding of how pharmaceutical or behavioral manipulations alter fear extinction in animals. Not only does fear extinction in rodents model exposure therapy in humans, where the latter is a cornerstone of behavioral intervention for anxiety disorders such as post-traumatic stress disorder and specific phobias, but also understanding more about extinction provides basic information into learning and memory processes and their underlying circuitry. In this paper, we briefly review three principal approaches that have been used to modulate extinction processes in animals and humans: a purely pharmacological approach, the more widespread approach of combining pharmacology with behavior, and a purely behavioral approach. The pharmacological studies comprise modulation by: brain derived neurotrophic factor (BDNF), d-cycloserine, serotonergic and noradrenergic drugs, neuropeptides, endocannabinoids, glucocorticoids, histone deacetylase (HDAC) inhibitors, and others. These studies strongly suggest that extinction can be modulated by drugs, behavioral interventions, or their combination, although not always in a lasting manner. We suggest that pharmacotherapeutic manipulations provide considerable promise for promoting effective and lasting fear reduction in individuals with anxiety disorders. PMID:24374101

Fuzzy pharmacology: theory and applications.

Science.gov (United States)

Sproule, Beth A; Naranjo, Claudio A; Türksen, I Burhan

2002-09-01

Fuzzy pharmacology is a term coined to represent the application of fuzzy logic and fuzzy set theory to pharmacological problems. Fuzzy logic is the science of reasoning, thinking and inference that recognizes and uses the real world phenomenon that everything is a matter of degree. It is an extension of binary logic that is able to deal with complex systems because it does not require crisp definitions and distinctions for the system components. In pharmacology, fuzzy modeling has been used for the mechanical control of drug delivery in surgical settings, and work has begun evaluating its use in other pharmacokinetic and pharmacodynamic applications. Fuzzy pharmacology is an emerging field that, based on these initial explorations, warrants further investigation.

Air-gating and chemical-gating in transistors and sensing devices made from hollow TiO2 semiconductor nanotubes

Science.gov (United States)

Alivov, Yahya; Funke, Hans; Nagpal, Prashant

2015-07-01

Rapid miniaturization of electronic devices down to the nanoscale, according to Moore’s law, has led to some undesirable effects like high leakage current in transistors, which can offset additional benefits from scaling down. Development of three-dimensional transistors, by spatial extension in the third dimension, has allowed higher contact area with a gate electrode and better control over conductivity in the semiconductor channel. However, these devices do not utilize the large surface area and interfaces for new electronic functionality. Here, we demonstrate air gating and chemical gating in hollow semiconductor nanotube devices and highlight the potential for development of novel transistors that can be modulated using channel bias, gate voltage, chemical composition, and concentration. Using chemical gating, we reversibly altered the conductivity of nanoscaled semiconductor nanotubes (10-500 nm TiO2 nanotubes) by six orders of magnitude, with a tunable rectification factor (ON/OFF ratio) ranging from 1-106. While demonstrated air- and chemical-gating speeds were slow here (˜seconds) due to the mechanical-evacuation rate and size of our chamber, the small nanoscale volume of these hollow semiconductors can enable much higher switching speeds, limited by the rate of adsorption/desorption of molecules at semiconductor interfaces. These chemical-gating effects are completely reversible, additive between different chemical compositions, and can enable semiconductor nanoelectronic devices for ‘chemical transistors’, ‘chemical diodes’, and very high-efficiency sensing applications.

Gate replacement at the Upper Lake Falls development

International Nuclear Information System (INIS)

Chen, C.T.; Locke, A.E.; Brown, E.R.

1998-01-01

Nova Scotia Power's integrated approach to dam safety was discussed. One of the two intake gates at Unit 1 of the Upper Falls Power Plant on the Mersey River was replaced in 1997 as part of the Utility's upgrading program. In the event of governor failure or turbine runaway, the new roller gate will allow operators to close the original sliding gate first under a more-or-less balanced head condition, and then to close the new roller gate under a full-flow condition. The planning, design and construction of the new roller gate is described. One of the two head gates of Unit 2 at the same station will be replaced in a similar fashion in the fall of 1998. 4 refs., 7 figs

Pulse wave as an alternate signal for data synchronization during gated myocardial perfusion SPECT imaging.

Science.gov (United States)

Lang, Otto; Trojanova, Helena; Balon, Helena R; Kunikova, Ivana; Bilwachs, Milos; Penicka, Martin; Kaminek, Milan; Myslivecek, Miroslav

2011-09-01

Proper identification of the cardiac cycle is essential for gated SPECT myocardial perfusion imaging. We have developed an alternate method of ECG for gating, that is, using the peripheral pulse wave (PW) as the triggering signal for gated SPECT acquisition. The aim of this study is to compare the use of this method of gating with the standard ECG trigger. We tested the PW triggering by comparing it with the ECG trigger. We evaluated 33 patients (25 males, 8 females), average age of 61 years (39-80) referred for stress myocardial perfusion imaging. Data from all patients were acquired twice and were processed by CEqual and QGS software. We compared the left ventricular ejection fraction (LVEF), end-diastolic and end-systolic volumes (EDV, ESV). Paired t test and Pearson correlation coefficient were used for comparison. The mean LVEF, EDV, and ESV calculated with the ECG trigger were 0.52, 120, and 64, respectively, those with the pulse-wave trigger were 0.48, 126, and 71, respectively. Mean paired difference for LVEF was -0.034 (P<0.001), for EDV 5.9 (P=0.012), and for ESV 7.9 (P<0.001). Pearson correlation coefficient for LVEF was 0.955, for EDV 0.987, and for ESV 0.991 (P<0.001 for all correlations). Triggering of gated-data acquisition by the PW is feasible. Quantitative parameters of cardiac function correlate highly with those obtained from the ECG trigger and the absolute differences are not clinically significant across a wide range of values.

Measurement of the effects and safety of Higenamine, a Chinese herbal medicine on cardiovascular system: Could it represent a new pharmacological myocardial stress agent?

International Nuclear Information System (INIS)

Zhang, Z.; Tao, Z.H.; Shi, R.F.; Zhang, X.; Liu, Y.Z.; He, Z.-X.; Chen, B.; Liu, X.J.

2003-01-01

Higenamine (HG) is a derivative of the medicinal herb, aconite root, that has been in use for several decades as a traditional medicine in the treatment of heart disease. The aim of this study was to investigate Higenamine as an alternative pharmacological agent to dobutamine (DB) for use in cardiac stress studies. Six dogs were infused intravenously with Higenamine in escalating doses of 1, 2 and 4 μg per kg of body weight per minute, each dose being given for a duration of 5 minutes and compared with dobutamine doses of 5, 10, and 20 μg/kg/min. Heart rate, blood pressure (systolic and diastolic), cardiac output, or aortic blood flow, myocardial oxygen consumption and coronary blood flow were measured with the physiological and electromagnetic flow devices at the beginning of the test and by the end of each dose-infusion. Left ventricular ejection fraction (LVEF) was measured with radionuclide ventriculography. ECG was monitored during the study. Another 8 dogs were administered Higenamine in escalating doses ranging from 1μg/kg/min and up to 500 μg/kg/min in order to observe the tolerability and safety of Higenamine. Heart rate, blood pressure and ECG were monitored during the test. Intravenous administration of Higenamine resulted in significant inotropic and chronotropic effects on the heart. Heart rate, myocardial oxygen consumption, cardiac output, coronary blood flow and LVEF all increased in a dose-dependent manner in both Higenamine and dobutamine tests. Higenamine did not cause significant change in systolic blood pressure, but a slight decrease in diastolic blood pressure was noted. Heart rate increased rapidly to the peak value, and then maintained a plateau level. No significant ECG abnormalities were demonstrated except for few occasional premature ventricular beats. None of the dogs died during the study. Hemodynamic studies demonstrated that Higenamine could be used as a pharmacologic cardiac stress agent with remarkable tolerability and safety

Myocardial perfusion scintigraphy 2007 in Germany. Results of the query and current status

Energy Technology Data Exchange (ETDEWEB)

Lindner, O. [Inst. fuer Radiologie, Nuklearmedizin und Molekulare Bildgebung, Herz- und Diabeteszentrum NRW, Bad Oeynhausen (Germany); Burchert, W. [Inst. fuer Radiologie, Nuklearmedizin und Molekulare Bildgebung, Herz- und Diabeteszentrum NRW, Bad Oeynhausen (Germany); Arbeitsgemeinschaft Kardiovaskulaere Nuklearmedizin der Deutschen Gesellschaft fuer Nuklearmedizin (Germany); Bengel, F.M. [Cardiovascular Nuclear Medicine, Johns Hopkins Medical Institutions, Baltimore (United States); Arbeitsgruppe Nuklearkardiologische Diagnostik der Deutschen Gesellschaft fuer Kardiologie (Germany); Zimmermann, R. [Arbeitsgruppe Nuklearkardiologische Diagnostik der Deutschen Gesellschaft fuer Kardiologie (Germany); Medizinische Klinik, Klinikum Pforzheim GmbH, Pforzheim (Germany); Dahl, J. vom [Klinik fuer Kardiologie, Kliniken Maria Hilf GmbH, Moenchengladbach (Germany); Schaefer, W. [Klinik fuer Nuklearmedizin, Universitaetsklinikum Aachen (Germany); Schober, O. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Muenster UKM (Germany); Schaefers, M. [Arbeitsgemeinschaft Kardiovaskulaere Nuklearmedizin der Deutschen Gesellschaft fuer Nuklearmedizin (Germany); Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Muenster UKM (Germany)

2009-07-01

Aim: This third survey of the working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine in cooperation with the working group Nuclear Cardiology of the German Cardiac Society was to deliver information on the procedures and in particular on the development of myocardial perfusion scintigraphy (MPS) from 2005 to 2007. Method: 370 questionnaires (222 private practices (PP), 117 hospitals (HO), 31 university hospitals (UH)) were evaluated. Results: MPS of 114,374 patients were reported, 83% were investigated with {sup 99m}Tc-perfusion tracers. 76% [2006=74%] were performed in PP, 15% [2006=17%] in HO and 9% [2006=9%] in UH. Diabetics represented 21% of all MPS patients in 2007. Data of 215 institutions which participated all from 2005 to 2007 showed an increase in MPS of 2.3% (PP +6.8%, HO -4.5%, UH -18.2%). The type of stress was pharmacological in 27% [2006 = 27%]; 67% adenosine (of these 25% with exercise), 31% dipyridamole (of these 55% with exercise), and 2% dobutamine. Gated SPECT was performed in 47% [2006 = 42%] of all rest and in 44% [2006 = 39%] of all stress MPS. 61% [2006 = 83%] of all institutions did not apply perfusion scores. 20% [2006 = 24%] of the institutions reported changes in the use of MPS by competing methods. Conclusion: There is a small increase of MPS between 2005 and 2007 despite competing methods. Gated SPECT has experienced more acceptance, but is still underrepresented. As compared to the European average and general standards of MPS a considerable backlog accounts to pharmacological stress tests, gated SPECT and perfusion scores. (orig.)

Myocardial perfusion scintigraphy 2007 in Germany. Results of the query and current status

International Nuclear Information System (INIS)

Lindner, O.; Burchert, W.; Bengel, F.M.; Zimmermann, R.; Dahl, J. vom; Schaefer, W.; Schober, O.; Schaefers, M.

2009-01-01

Aim: This third survey of the working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine in cooperation with the working group Nuclear Cardiology of the German Cardiac Society was to deliver information on the procedures and in particular on the development of myocardial perfusion scintigraphy (MPS) from 2005 to 2007. Method: 370 questionnaires (222 private practices (PP), 117 hospitals (HO), 31 university hospitals (UH)) were evaluated. Results: MPS of 114,374 patients were reported, 83% were investigated with 99m Tc-perfusion tracers. 76% [2006=74%] were performed in PP, 15% [2006=17%] in HO and 9% [2006=9%] in UH. Diabetics represented 21% of all MPS patients in 2007. Data of 215 institutions which participated all from 2005 to 2007 showed an increase in MPS of 2.3% (PP +6.8%, HO -4.5%, UH -18.2%). The type of stress was pharmacological in 27% [2006 = 27%]; 67% adenosine (of these 25% with exercise), 31% dipyridamole (of these 55% with exercise), and 2% dobutamine. Gated SPECT was performed in 47% [2006 = 42%] of all rest and in 44% [2006 = 39%] of all stress MPS. 61% [2006 = 83%] of all institutions did not apply perfusion scores. 20% [2006 = 24%] of the institutions reported changes in the use of MPS by competing methods. Conclusion: There is a small increase of MPS between 2005 and 2007 despite competing methods. Gated SPECT has experienced more acceptance, but is still underrepresented. As compared to the European average and general standards of MPS a considerable backlog accounts to pharmacological stress tests, gated SPECT and perfusion scores. (orig.)

Lippia citrodora: a review on its phytochemistry and pharmacological activities

Directory of Open Access Journals (Sweden)

2017-11-01

Full Text Available Background and objectives: Lippia citrodora commonly known as lemon verbena is a species of flowering plant in the verbena family, native to western South America. With its antioxidant effects, it is mostly used in folk medicine to treat anti-inflammatory diseases, and diseases associated with oxidative stress. This review has presented a summary on L. citordora’s phytochemistry and its pharmacological activities. It will also discuss gaps and challenges needed to be solved. Methods: Electronic database including Web of Science, PubMed, Science Direct and Google Scholar were searched for articles published between 1973 and 2017 regarding the phytochemistry and biological activities of L. citodora. Results: Traditional uses of this plant were specially related to coagulation system, digestive system and brain. Phytochemical investigations identified flavonoids, terpenes, iridois, lignins, phenylethanoid, as the main components of the plant. Antimicrobial, neuroprotective, antinociceptive, anti hyperpropulsive, sedative, anticolitis, anxiolytic, anticonvulsant, antihyperalgesic, and anticancer properties were among the pharmacological activities of L. citriodora. The plant extract and essential oil had also demonstrated high antioxidant activity. Conclusion: Modern pharmacological studies have now validated many traditional uses of L. citrodora. The data reviewed here revealed that this plant is a potential source for the treatment of a wide range of diseases specially inflammatory diseases and neurological dysfunctions. Future human studies are needed for further confirmation of the therapeutic activities of L. citriodora.

Pharmacologic and non-pharmacologic treatments for chronic pain in individuals with HIV: a systematic review

Science.gov (United States)

Merlin, Jessica S.; Bulls, Hailey W.; Vucovich, Lee A.; Edelman, E. Jennifer; Starrels, Joanna L.

2016-01-01

Chronic pain occurs in as many as 85% of individuals with HIV and is associated with substantial functional impairment. Little guidance is available for HIV providers seeking to address their patients’ chronic pain. We conducted a systematic review to identify clinical trials and observational studies that examined the impact of pharmacologic or non-pharmacologic interventions on pain and/or functional outcomes among HIV-infected individuals with chronic pain in high-development countries. Eleven studies met inclusion criteria and were mostly low or very low quality. Seven examined pharmacologic interventions (gabapentin, pregabalin, capsaicin, analgesics including opioids) and four examined non-pharmacologic interventions (cognitive behavioral therapy, self-hypnosis, smoked cannabis). The only controlled studies with positive results were of capsaicin and cannabis, and had short-term follow-up (≤12 weeks). Among the seven studies of pharmacologic interventions, five had substantial pharmaceutical industry sponsorship. These findings highlight several important gaps in the HIV/chronic pain literature that require further research. PMID:27267445

Gate valve performance prediction

International Nuclear Information System (INIS)

Harrison, D.H.; Damerell, P.S.; Wang, J.K.; Kalsi, M.S.; Wolfe, K.J.

1994-01-01

The Electric Power Research Institute is carrying out a program to improve the performance prediction methods for motor-operated valves. As part of this program, an analytical method to predict the stem thrust required to stroke a gate valve has been developed and has been assessed against data from gate valve tests. The method accounts for the loads applied to the disc by fluid flow and for the detailed mechanical interaction of the stem, disc, guides, and seats. To support development of the method, two separate-effects test programs were carried out. One test program determined friction coefficients for contacts between gate valve parts by using material specimens in controlled environments. The other test program investigated the interaction of the stem, disc, guides, and seat using a special fixture with full-sized gate valve parts. The method has been assessed against flow-loop and in-plant test data. These tests include valve sizes from 3 to 18 in. and cover a considerable range of flow, temperature, and differential pressure. Stem thrust predictions for the method bound measured results. In some cases, the bounding predictions are substantially higher than the stem loads required for valve operation, as a result of the bounding nature of the friction coefficients in the method

Double-disc gate valve

International Nuclear Information System (INIS)

Wheatley, S.J.

1979-01-01

The invention relates to an improvement in a conventional double-disc gate valve having a vertically movable gate assembly including a wedge, spreaders slidably engaged therewith, a valve disc carried by the spreaders. When the gate assembly is lowered to a selected point in the valve casing, the valve discs are moved transversely outward to close inlet and outlet ports in the casing. The valve includes hold-down means for guiding the disc-and-spreader assemblies as they are moved transversely outward and inward. If such valves are operated at relatively high differential pressures, they sometimes jam during opening. Such jamming has been a problem for many years in gate valves used in gaseous diffusion plants for the separation of uranium isotopes. The invention is based on the finding that the above-mentioned jamming results when the outlet disc tilts about its horizontal axis in a certain way during opening of the valve. In accordance with the invention, tilting of the outlet disc is maintained at a tolerable value by providing the disc with a rigid downwardly extending member and by providing the casing with a stop for limiting inward arcuate movement of the member to a preselected value during opening of the valve

[STUDYING THE ROLE OF BRAIN MELANOCORTIN RECEPTORS IN THE SUPPRESSING OF FOOD INTAKE UNDER ETHER STRESS IN MICE].

Science.gov (United States)

Bazhan, N M; Kulikova, E V; Makarova, E N; Yakovleva, T V; Kazantseva, A Yu

2015-12-01

Melanocortin (MC) system regulates food intake under the rest conditions. Stress inhibits food intake. It is not clear whether brain MC system is involved in stress-induced anorexia in mice. The aim of the work was to investigate the effect of pharmacological blockade and activation of brain MC receptors on food intake under stress. C57B1/6J male mice were subjected to ether stress (0.5 minute ether anesthesia) before the administration of saline solution or synthetic non-selective blocker (SHU9119) or agonist (Melanotan II) of MC receptors into the lateral brain ventricle. Food intake was pre-stimulated with 17 hours of fasting in all mice. Ether stress decreased food intake, increased the plasma corticosterone level and hypothalamic mRNA AgRP (natural MC receptor antagonist) level at 1 hour after the stress. Pharmacological blockade of the MC receptors weakened stress-induced anorexia and decreased mRNA AgRP level in the hypothalamus. Pharmacological stimulation of the MC receptors enhanced ether stress-induced anorexia and hypercortisolism. Thus, our data demonstrated that the central MC system was involved in the development of stress-induced anorexia in mice.

The pharmacology of regenerative medicine.

Science.gov (United States)

Christ, George J; Saul, Justin M; Furth, Mark E; Andersson, Karl-Erik

2013-07-01

Regenerative medicine is a rapidly evolving multidisciplinary, translational research enterprise whose explicit purpose is to advance technologies for the repair and replacement of damaged cells, tissues, and organs. Scientific progress in the field has been steady and expectations for its robust clinical application continue to rise. The major thesis of this review is that the pharmacological sciences will contribute critically to the accelerated translational progress and clinical utility of regenerative medicine technologies. In 2007, we coined the phrase "regenerative pharmacology" to describe the enormous possibilities that could occur at the interface between pharmacology, regenerative medicine, and tissue engineering. The operational definition of regenerative pharmacology is "the application of pharmacological sciences to accelerate, optimize, and characterize (either in vitro or in vivo) the development, maturation, and function of bioengineered and regenerating tissues." As such, regenerative pharmacology seeks to cure disease through restoration of tissue/organ function. This strategy is distinct from standard pharmacotherapy, which is often limited to the amelioration of symptoms. Our goal here is to get pharmacologists more involved in this field of research by exposing them to the tools, opportunities, challenges, and interdisciplinary expertise that will be required to ensure awareness and galvanize involvement. To this end, we illustrate ways in which the pharmacological sciences can drive future innovations in regenerative medicine and tissue engineering and thus help to revolutionize the discovery of curative therapeutics. Hopefully, the broad foundational knowledge provided herein will spark sustained conversations among experts in diverse fields of scientific research to the benefit of all.

Rapidly reconfigurable all-optical universal logic gate

Science.gov (United States)

Goddard, Lynford L.; Bond, Tiziana C.; Kallman, Jeffrey S.

2010-09-07

A new reconfigurable cascadable all-optical on-chip device is presented. The gate operates by combining the Vernier effect with a novel effect, the gain-index lever, to help shift the dominant lasing mode from a mode where the laser light is output at one facet to a mode where it is output at the other facet. Since the laser remains above threshold, the speed of the gate for logic operations as well as for reprogramming the function of the gate is primarily limited to the small signal optical modulation speed of the laser, which can be on the order of up to about tens of GHz. The gate can be rapidly and repeatedly reprogrammed to perform any of the basic digital logic operations by using an appropriate analog optical or electrical signal at the gate selection port. Other all-optical functionality includes wavelength conversion, signal duplication, threshold switching, analog to digital conversion, digital to analog conversion, signal routing, and environment sensing. Since each gate can perform different operations, the functionality of such a cascaded circuit grows exponentially.

The gated blood pool scan in the evaluation of coronary artery disease

International Nuclear Information System (INIS)

Anger, K.; Erbel, R.; Krebs, W.; Meyer, J.; Moeller, T.; Schweizer, P.; Yalkinoglu, O.; Technische Hochschule Aachen

1983-01-01

38 patients with clinically suspected coronary artery disease were studied by contrast ventriculography, 2-dimensional echocardiography and multiple gated blood pool imaging (MUGA) without stress. The results were compared with eath other and with the final diagnosis confirmed by coronary angiography. The left ventricular ejection fraction is evaluated nearly identically and with sufficient accuracy by both non-invasive methods, local motion abnormalities are on the other hand diagnosed in the best way by MUGA imaging in our own cases. (orig.) [de

Penn State DOE GATE Program

Energy Technology Data Exchange (ETDEWEB)

Anstrom, Joel

2012-08-31

The Graduate Automotive Technology Education (GATE) Program at The Pennsylvania State University (Penn State) was established in October 1998 pursuant to an award from the U.S. Department of Energy (U.S. DOE). The focus area of the Penn State GATE Program is advanced energy storage systems for electric and hybrid vehicles.

The D1CT-7 mouse model of Tourette syndrome displays sensorimotor gating deficits in response to spatial confinement.

Science.gov (United States)

Godar, Sean C; Mosher, Laura J; Strathman, Hunter J; Gochi, Andrea M; Jones, Cori M; Fowler, Stephen C; Bortolato, Marco

2016-07-01

The D1CT-7 mouse is one of the best known animal models of Tourette syndrome (TS), featuring spontaneous tic-like behaviours sensitive to standard TS therapies; these characteristics ensure a high face and predictive validity of this model, yet its construct validity remains elusive. To address this issue, we studied the responses of D1CT-7 mice to two critical components of TS pathophysiology: the exacerbation of tic-like behaviours in response to stress and the presence of sensorimotor gating deficits, which are thought to reflect the perceptual alterations causing the tics. D1CT-7 and wild-type (WT) littermates were subjected to a 20 min session of spatial confinement (SC) within an inescapable, 10 cm wide cylindrical enclosure. Changes in plasma corticosterone levels, tic-like behaviours and other spontaneous responses were measured. SC-exposed mice were also tested for the prepulse inhibition (PPI) of the startle response (a sensorimotor gating index) and other TS-related behaviours, including open-field locomotion, novel object exploration and social interaction and compared with non-confined counterparts. SC produced a marked increase in corticosterone concentrations in both D1CT-7 and WT mice. In D1CT-7, but not WT mice, SC exacerbated tic-like and digging behaviours, and triggered PPI deficits and aggressive responses. Conversely, SC did not modify locomotor activity or novel object exploration in D1CT-7 mice. Both tic-like behaviours and PPI impairments in SC-exposed D1CT-7 mice were inhibited by standard TS therapies and D1 dopamine receptor antagonism. These findings collectively support the translational and construct validity of D1CT-7 mice with respect to TS. This article is part of a themed section on Updating Neuropathology and Neuropharmacology of Monoaminergic Systems. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v173.13/issuetoc. © 2015 The British Pharmacological Society.

Two-dimensional simulation of the thermal stress effect on static and dynamic VDMOS characteristics

International Nuclear Information System (INIS)

Alwan, M.; Beydoun, B.; Ketata, K.; Zoaeter, M.

2005-01-01

Using a two-dimensional simulator, the effect of the thermal stress on static and dynamic vertical double-diffusion metal oxide semiconductor (VDMOS) characteristics have been investigated. The use of the device under certain thermal stress conditions can produce modifications of its physical and electrical properties. Based on physics and 2D simulations, this paper proposes an analysis of this stress effect observed on the electrical characteristics of the device. Parameters responsible of these modifications are determined. Approximate expressions of the ionization coefficients and breakdown voltage in terms of temperature are proposed. Non-punch-through junction theory is used to express the breakdown voltage and the space charge extension with respect to the impurity concentration and the temperature. The capacitances of the device have been also studied. The effect of the stress on C-V characteristics is observed and analyzed. We notice that the drain-gate, drain-source and gate-source capacitances are shifted due to the degradation of device physical properties versus thermal stress

Effects of early life stress: Opportunities for pharmacological intervention

NARCIS (Netherlands)

Loi, M

2016-01-01

Moderate acute activation of the body’s stress response system is considered an adaptive mechanism that increases the chance of survival, but severe stressors early in life may disturb brain development. In agreement, epidemiological data suggest that adverse experiences early in life, such as

Comparison of myocardial function between post-menopausal and pre-menopausal women: evaluation by gated myocardial SPECT

International Nuclear Information System (INIS)

Hwang, K. H.; Choa, Won Sick; Yoon, Min Ki

2005-01-01

In addition to inhibiting coronary atherosclerosis, estrogen is expected to have protective effects on cardiac myocytes. We investigated the difference in myocardial functional parameters evaluated by gated myocardial SPECT after adenosine-stress between post-menopausal and pre-menopausal healthy women. This study included 22 healthy post-menopausal women (mean age: 53.0 yr) and 20 pre-menopausal women (mean age: 43.0 yr) who performed Tc-99m tetrofosmin gated myocardial SPECT after adenosine-stress. Measured hemodynamic parameters, EDV, ESV, stroke volume, EF, cardiac output and cardiac index were compared between the two groups. For comparison, similar-aged two male groups with matched numbers were also studied. There was no significant difference in hemodynamic parameters. EDV, ESV, stroke volume, EF, or cardiac output between the post-menopausal and pre-menopausal women. However, post-menopausal women have a smaller cardiac index (mean: 1.95 L/min/m2 vs 2.20 L/min/m2; p=0.045) and adenosine-induced HR increase (mean : 80.5/min vs 89.7/min ; p=0.03), compared to the pre-menopausal women. On the contrary, the two male groups of the same age range and numbers with the women groups showed no significant difference in any myocardial parameters. These results suggest that menopause may be correlated with reduced increase in cardiac index and HR increase after adenosine-stress

Comparison of myocardial function between post-menopausal and pre-menopausal women: evaluation by gated myocardial SPECT

Energy Technology Data Exchange (ETDEWEB)

Hwang, K. H.; Choa, Won Sick; Yoon, Min Ki [Gachon Medical School, Gil Hospital, Incheon (Korea, Republic of)

2005-07-01

In addition to inhibiting coronary atherosclerosis, estrogen is expected to have protective effects on cardiac myocytes. We investigated the difference in myocardial functional parameters evaluated by gated myocardial SPECT after adenosine-stress between post-menopausal and pre-menopausal healthy women. This study included 22 healthy post-menopausal women (mean age: 53.0 yr) and 20 pre-menopausal women (mean age: 43.0 yr) who performed Tc-99m tetrofosmin gated myocardial SPECT after adenosine-stress. Measured hemodynamic parameters, EDV, ESV, stroke volume, EF, cardiac output and cardiac index were compared between the two groups. For comparison, similar-aged two male groups with matched numbers were also studied. There was no significant difference in hemodynamic parameters. EDV, ESV, stroke volume, EF, or cardiac output between the post-menopausal and pre-menopausal women. However, post-menopausal women have a smaller cardiac index (mean: 1.95 L/min/m2 vs 2.20 L/min/m2; p=0.045) and adenosine-induced HR increase (mean : 80.5/min vs 89.7/min ; p=0.03), compared to the pre-menopausal women. On the contrary, the two male groups of the same age range and numbers with the women groups showed no significant difference in any myocardial parameters. These results suggest that menopause may be correlated with reduced increase in cardiac index and HR increase after adenosine-stress.

Threading dislocation movement in AlGaN/GaN-on-Si high electron mobility transistors under high temperature reverse bias stressing

Directory of Open Access Journals (Sweden)

W. A. Sasangka

2016-09-01

Full Text Available Dislocations are known to be associated with both physical and electrical degradation mechanisms of AlGaN/GaN-on-Si high electron mobility transistors (HEMTs. We have observed threading dislocation movement toward the gate-edges in AlGaN/GaN-on-Si HEMT under high reverse bias stressing. Stressed devices have higher threading dislocation densities (i.e. ∼5 × 109/cm2 at the gate-edges, as compared to unstressed devices (i.e. ∼2.5 × 109/cm2. Dislocation movement correlates well with high tensile stress (∼1.6 GPa at the gate-edges, as seen from inverse piezoelectric calculations and x-ray synchrotron diffraction residual stress measurements. Based on Peierls stress calculation, we believe that threading dislocations move via glide in 〈 11 2 ¯ 0 〉 / { 1 1 ¯ 00 } and 〈 11 2 ¯ 0 〉 / { 1 1 ¯ 01 } slip systems. This result illustrates the importance of threading dislocation mobility in controlling the reliability of AlGaN/GaN-on-Si HEMTs.

Implementation of a funnel-and-gate remediation system

International Nuclear Information System (INIS)

O'Brien, K.; Keyes, G.; Sherman, N.

1997-01-01

A funnel-and-gate trademark system incorporating activated carbon was deemed the most attractive remediation method for an active lumber mill in the western United States. Petroleum hydrocarbons, chlorinated solvents, pentachlorophenol, and tetrachlorophenol were detected in on-site groundwater samples. The shallow aquifer consists of a heterogeneous mixture of marine deposits and artificial fill, underlain by low-permeability siltstones and mudstone. In the funnel-and-gate trademark system, a low-permeability cutoff wall was installed to funnel groundwater flow to a smaller area (a open-quotes gateclose quotes) where a passive below-grade treatment system treats the plume as it flows through the gate. Groundwater flow modeling focused on the inhomogeneities of the aquifer and the spatial relationship between gate(s) and barrier walls. The gate design incorporates several factors, including contaminant concentration, flow rate, and time between carbon changeouts. To minimize back pressure and maximize residence time, each gate was designed using 1.25-meter (4-foot) diameter corrugated metal pipe filled with a 1.25-meter (4-foot) thick bed of activated carbon. The configuration will allow water to flow through the treatment gates without pumps. The installed system is 190 meters (625 feet) long and treats approximately 76 L/min (20 gpm) during the winter months

Universal Fault-Tolerant Gates on Concatenated Stabilizer Codes

Directory of Open Access Journals (Sweden)

Theodore J. Yoder

2016-09-01

Full Text Available It is an oft-cited fact that no quantum code can support a set of fault-tolerant logical gates that is both universal and transversal. This no-go theorem is generally responsible for the interest in alternative universality constructions including magic state distillation. Widely overlooked, however, is the possibility of nontransversal, yet still fault-tolerant, gates that work directly on small quantum codes. Here, we demonstrate precisely the existence of such gates. In particular, we show how the limits of nontransversality can be overcome by performing rounds of intermediate error correction to create logical gates on stabilizer codes that use no ancillas other than those required for syndrome measurement. Moreover, the logical gates we construct, the most prominent examples being Toffoli and controlled-controlled-Z, often complete universal gate sets on their codes. We detail such universal constructions for the smallest quantum codes, the 5-qubit and 7-qubit codes, and then proceed to generalize the approach. One remarkable result of this generalization is that any nondegenerate stabilizer code with a complete set of fault-tolerant single-qubit Clifford gates has a universal set of fault-tolerant gates. Another is the interaction of logical qubits across different stabilizer codes, which, for instance, implies a broadly applicable method of code switching.

Gating of long-term potentiation by nicotinic acetylcholine receptors at the cerebellum input stage.

Directory of Open Access Journals (Sweden)

Francesca Prestori

Full Text Available The brain needs mechanisms able to correlate plastic changes with local circuit activity and internal functional states. At the cerebellum input stage, uncontrolled induction of long-term potentiation or depression (LTP or LTD between mossy fibres and granule cells can saturate synaptic capacity and impair cerebellar functioning, which suggests that neuromodulators are required to gate plasticity processes. Cholinergic systems innervating the cerebellum are thought to enhance procedural learning and memory. Here we show that a specific subtype of acetylcholine receptors, the α7-nAChRs, are distributed both in cerebellar mossy fibre terminals and granule cell dendrites and contribute substantially to synaptic regulation. Selective α7-nAChR activation enhances the postsynaptic calcium increase, allowing weak mossy fibre bursts, which would otherwise cause LTD, to generate robust LTP. The local microperfusion of α7-nAChR agonists could also lead to in vivo switching of LTD to LTP following sensory stimulation of the whisker pad. In the cerebellar flocculus, α7-nAChR pharmacological activation impaired vestibulo-ocular-reflex adaptation, probably because LTP was saturated, preventing the fine adjustment of synaptic weights. These results show that gating mechanisms mediated by specific subtypes of nicotinic receptors are required to control the LTD/LTP balance at the mossy fibre-granule cell relay in order to regulate cerebellar plasticity and behavioural adaptation.

Protonic/electronic hybrid oxide transistor gated by chitosan and its full-swing low voltage inverter applications

Energy Technology Data Exchange (ETDEWEB)

Chao, Jin Yu [Shanxi Province Key Laboratory High Gravity Chemical Engineering, North University of China, Taiyuan 030051 (China); Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Zhu, Li Qiang, E-mail: lqzhu@nimte.ac.cn; Xiao, Hui [Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Yuan, Zhi Guo, E-mail: ncityzg@163.com [Shanxi Province Key Laboratory High Gravity Chemical Engineering, North University of China, Taiyuan 030051 (China)

2015-12-21

Modulation of charge carrier density in condensed materials based on ionic/electronic interaction has attracted much attention. Here, protonic/electronic hybrid indium-zinc-oxide (IZO) transistors gated by chitosan based electrolyte were obtained. The chitosan-based electrolyte illustrates a high proton conductivity and an extremely strong proton gating behavior. The transistor illustrates good electrical performances at a low operating voltage of ∼1.0 V such as on/off ratio of ∼3 × 10{sup 7}, subthreshold swing of ∼65 mV/dec, threshold voltage of ∼0.3 V, and mobility of ∼7 cm{sup 2}/V s. Good positive gate bias stress stabilities are obtained. Furthermore, a low voltage driven resistor-loaded inverter was built by using an IZO transistor in series with a load resistor, exhibiting a linear relationship between the voltage gain and the supplied voltage. The inverter is also used for decreasing noises of input signals. The protonic/electronic hybrid IZO transistors have potential applications in biochemical sensors and portable electronics.

Cleaning Challenges of High-κ/Metal Gate Structures

KAUST Repository

Hussain, Muhammad Mustafa; Shamiryan, Denis G.; Paraschiv, Vasile; Sano, Kenichi; Reinhardt, Karen A.

2010-01-01

High-κ/metal gates are used as transistors for advanced logic applications to improve speed and eliminate electrical issues associated with polySi and SiO2 gates. Various integration schemes are possible and will be discussed, such as dual gate, gate-first, and gate-last, both of which require specialized cleaning and etching steps. Specific areas of discussion will include cleaning and conditioning of the silicon surface, forming a high-quality chemical oxide, removal of the high-κ dielectric with selectivity to the SiO2 layer, cleaning and residue removal after etching, and prevention of galvanic corrosion during cleaning. © 2011 Scrivener Publishing LLC. All rights reserved.

Cleaning Challenges of High-κ/Metal Gate Structures

KAUST Repository

Hussain, Muhammad Mustafa

2010-12-20

High-κ/metal gates are used as transistors for advanced logic applications to improve speed and eliminate electrical issues associated with polySi and SiO2 gates. Various integration schemes are possible and will be discussed, such as dual gate, gate-first, and gate-last, both of which require specialized cleaning and etching steps. Specific areas of discussion will include cleaning and conditioning of the silicon surface, forming a high-quality chemical oxide, removal of the high-κ dielectric with selectivity to the SiO2 layer, cleaning and residue removal after etching, and prevention of galvanic corrosion during cleaning. © 2011 Scrivener Publishing LLC. All rights reserved.

Pharmacologic inhibition of S1P attenuates ATF6 expression, causes ER stress and contributes to apoptotic cell death.

Science.gov (United States)

Lebeau, Paul; Byun, Jae Hyun; Yousof, Tamana; Austin, Richard C

2018-04-22

Mammalian cells express unique transcription factors embedded in the endoplasmic reticulum (ER) membrane, such as the sterol regulatory element-binding proteins (SREBPs), that promote de novo lipogenesis. Upon their release from the ER, the SREBPs require proteolytic activation in the Golgi by site-1-protease (S1P). As such, inhibition of S1P, using compounds such as PF-429242 (PF), reduces cholesterol synthesis and may represent a new strategy for the management of dyslipidemia. In addition to the SREBPs, the unfolded protein response (UPR) transducer, known as the activating transcription factor 6 (ATF6), is another ER membrane-bound transcription factor that requires S1P-mediated activation. ATF6 regulates ER protein folding capacity by promoting the expression of ER chaperones such as the 78-kDa glucose-regulated protein (GRP78). ER-resident chaperones like GRP78 prevent and/or resolve ER polypeptide accumulation and subsequent ER stress-induced UPR activation by folding nascent polypeptides. Here we report that pharmacological inhibition of S1P reduced the expression of ATF6 and GRP78 and induced the activation of UPR transducers inositol-requiring enzyme-1α (IRE1α) and protein kinase RNA-like ER kinase (PERK). As a consequence, S1P inhibition also increased the susceptibility of cells to ER stress-induced cell death. Our findings suggest that S1P plays a crucial role in the regulation of ER folding capacity and also identifies a compensatory cross-talk between UPR transducers in order to maintain adequate ER chaperone expression and activity. Copyright © 2018. Published by Elsevier Inc.

High frequency MOSFET gate drivers technologies and applications

CERN Document Server

Zhang, Zhiliang

2017-01-01

This book describes high frequency power MOSFET gate driver technologies, including gate drivers for GaN HEMTs, which have great potential in the next generation of switching power converters. Gate drivers serve as a critical role between control and power devices.

The clinical implementation of respiratory-gated intensity-modulated radiotherapy

International Nuclear Information System (INIS)

Keall, Paul; Vedam, Sastry; George, Rohini; Bartee, Chris; Siebers, Jeffrey; Lerma, Fritz; Weiss, Elisabeth; Chung, Theodore

2006-01-01

The clinical use of respiratory-gated radiotherapy and the application of intensity-modulated radiotherapy (IMRT) are 2 relatively new innovations to the treatment of lung cancer. Respiratory gating can reduce the deleterious effects of intrafraction motion, and IMRT can concurrently increase tumor dose homogeneity and reduce dose to critical structures including the lungs, spinal cord, esophagus, and heart. The aim of this work is to describe the clinical implementation of respiratory-gated IMRT for the treatment of non-small cell lung cancer. Documented clinical procedures were developed to include a tumor motion study, gated CT imaging, IMRT treatment planning, and gated IMRT delivery. Treatment planning procedures for respiratory-gated IMRT including beam arrangements and dose-volume constraints were developed. Quality assurance procedures were designed to quantify both the dosimetric and positional accuracy of respiratory-gated IMRT, including film dosimetry dose measurements and Monte Carlo dose calculations for verification and validation of individual patient treatments. Respiratory-gated IMRT is accepted by both treatment staff and patients. The dosimetric and positional quality assurance test results indicate that respiratory-gated IMRT can be delivered accurately. If carefully implemented, respiratory-gated IMRT is a practical alternative to conventional thoracic radiotherapy. For mobile tumors, respiratory-gated radiotherapy is used as the standard of care at our institution. Due to the increased workload, the choice of IMRT is taken on a case-by-case basis, with approximately half of the non-small cell lung cancer patients receiving respiratory-gated IMRT. We are currently evaluating whether superior tumor coverage and limited normal tissue dosing will lead to improvements in local control and survival in non-small cell lung cancer

Prefrontal cortex executive processes affected by stress in health and disease.

Science.gov (United States)

Girotti, Milena; Adler, Samantha M; Bulin, Sarah E; Fucich, Elizabeth A; Paredes, Denisse; Morilak, David A

2017-07-06

Prefrontal cortical executive functions comprise a number of cognitive capabilities necessary for goal directed behavior and adaptation to a changing environment. Executive dysfunction that leads to maladaptive behavior and is a symptom of psychiatric pathology can be instigated or exacerbated by stress. In this review we survey research addressing the impact of stress on executive function, with specific focus on working memory, attention, response inhibition, and cognitive flexibility. We then consider the neurochemical pathways underlying these cognitive capabilities and, where known, how stress alters them. Finally, we review work exploring potential pharmacological and non-pharmacological approaches that can ameliorate deficits in executive function. Both preclinical and clinical literature indicates that chronic stress negatively affects executive function. Although some of the circuitry and neurochemical processes underlying executive function have been characterized, a great deal is still unknown regarding how stress affects these processes. Additional work focusing on this question is needed in order to make progress on developing interventions that ameliorate executive dysfunction. Published by Elsevier Inc.

Light-effect transistor (LET) with multiple independent gating controls for optical logic gates and optical amplification

Science.gov (United States)

Marmon, Jason; Rai, Satish; Wang, Kai; Zhou, Weilie; Zhang, Yong

The pathway for CMOS technology beyond the 5-nm technology node remains unclear for both physical and technological reasons. A new transistor paradigm is required. A LET (Marmon et. al., Front. Phys. 2016, 4, No. 8) offers electronic-optical hybridization at the component level, and is capable of continuing Moore's law to the quantum scale. A LET overcomes a FET's fabrication complexity, e.g., physical gate and doping, by employing optical gating and photoconductivity, while multiple independent, optical gates readily realize unique functionalities. We report LET device characteristics and novel digital and analog applications, such as optical logic gates and optical amplification. Prototype CdSe-nanowire-based LETs, incorporating an M-S-M structure, show output and transfer characteristics resembling advanced FETs, e.g., on/off ratios up to 106 with a source-drain voltage of 1.43V, gate-power of 260nW, and a subthreshold swing of 0.3nW/decade (excluding losses). A LET has potential for high-switching (THz) speeds and extremely low-switching energies (aJ) in the ballistic transport region. Our work offers new electronic-optical integration strategies for high speed and low energy computing approaches, which could potentially be extended to other materials and devices.

Effects of Gate Stack Structural and Process Defectivity on High-k Dielectric Dependence of NBTI Reliability in 32 nm Technology Node PMOSFETs

Directory of Open Access Journals (Sweden)

H. Hussin

2014-01-01

Full Text Available We present a simulation study on negative bias temperature instability (NBTI induced hole trapping in E′ center defects, which leads to depassivation of interface trap precursor in different geometrical structures of high-k PMOSFET gate stacks using the two-stage NBTI model. The resulting degradation is characterized based on the time evolution of the interface and hole trap densities, as well as the resulting threshold voltage shift. By varying the physical thicknesses of the interface silicon dioxide (SiO2 and hafnium oxide (HfO2 layers, we investigate how the variation in thickness affects hole trapping/detrapping at different stress temperatures. The results suggest that the degradations are highly dependent on the physical gate stack parameters for a given stress voltage and temperature. The degradation is more pronounced by 5% when the thicknesses of HfO2 are increased but is reduced by 11% when the SiO2 interface layer thickness is increased during lower stress voltage. However, at higher stress voltage, greater degradation is observed for a thicker SiO2 interface layer. In addition, the existence of different stress temperatures at which the degradation behavior differs implies that the hole trapping/detrapping event is thermally activated.

Silicon photonic crystal all-optical logic gates

Energy Technology Data Exchange (ETDEWEB)

Fu, Yulan [State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871 (China); Hu, Xiaoyong, E-mail: xiaoyonghu@pku.edu.cn [State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871 (China); Gong, Qihuang, E-mail: qhgong@pku.edu.cn [State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871 (China)

2013-01-03

All-optical logic gates, including OR, XOR, NOT, XNOR, and NAND gates, are realized theoretically in a two-dimensional silicon photonic crystal using the light beam interference effect. The ingenious photonic crystal waveguide component design, the precisely controlled optical path difference, and the elaborate device configuration ensure the simultaneous realization of five types of logic gate with low-power and a contrast ratio between the logic states of “1” and “0” as high as 20 dB. High power is not necessary for operation of these logic gate devices. This offers a simple and effective approach for the realization of integrated all-optical logic devices.

Electrocardiographic gating in positron emission computed tomography

International Nuclear Information System (INIS)

Hoffman, E.J.; Phelps, M.E.; Wisenberg, G.; Schelbert, H.R.; Kuhl, D.E.

1979-01-01

Electrocardiographic (ECG) synchronized multiple gated data acquisition was employed with positron emission computed tomography (ECT) to obtain images of myocardial blood pool and myocardium. The feasibility and requirements of multiple gated data acquisition in positron ECT were investigated for 13NH3, ( 18 F)-2-fluoro-2-D-deoxyglucose, and ( 11 C)-carboxyhemoglobin. Examples are shown in which image detail is enhanced and image interpretation is facilitated when ECG gating is employed in the data collection. Analysis of count rate data from a series of volunteers indicates that multiple, statistically adequate images can be obtained under a multiple gated data collection format without an increase in administered dose

Enhanced transconductance in a double-gate graphene field-effect transistor

Science.gov (United States)

Hwang, Byeong-Woon; Yeom, Hye-In; Kim, Daewon; Kim, Choong-Ki; Lee, Dongil; Choi, Yang-Kyu

2018-03-01

Multi-gate transistors, such as double-gate, tri-gate and gate-all-around transistors are the most advanced Si transistor structure today. Here, a genuine double-gate transistor with a graphene channel is experimentally demonstrated. The top and bottom gates of the double-gate graphene field-effect transistor (DG GFET) are electrically connected so that the conductivity of the graphene channel can be modulated simultaneously by both the top and bottom gate. A single-gate graphene field-effect transistor (SG GFET) with only the top gate is also fabricated as a control device. For systematical analysis, the transfer characteristics of both GFETs were measured and compared. Whereas the maximum transconductance of the SG GFET was 17.1 μS/μm, that of the DG GFET was 25.7 μS/μm, which is approximately a 50% enhancement. The enhancement of the transconductance was reproduced and comprehensively explained by a physics-based compact model for GFETs. The investigation of the enhanced transfer characteristics of the DG GFET in this work shows the possibility of a multi-gate architecture for high-performance graphene transistor technology.

Emergency Gate Vibration of the Pipe-Turbine Model

Directory of Open Access Journals (Sweden)

Andrej Predin

2000-01-01

Full Text Available The vibration behavior of an emergency gate situated on a horizontal-shaft Kaplan turbine is studied. The analysis and transfer of the dynamic movements of the gate are quite complex. In particular the behavior is examined of the emergency gate for the case when the power unit is disconnected from the system or there is a breakdown of the guide vane system at the moment when the maximal head and capacity are achieved. Experimental-numerical methods both in the time domain and in the frequency domain are employed. Natural vibrations characterize a first zone, corresponding to relatively small gate openings. As the gate opening increases, the vibration behavior of the gate becomes increasingly dependent on the swirl pulsations in the draft tube of the turbine. Finally, the data transfer from the model to the prototype by use of the dynamic similitude law is discussed.

ECG-gating in non-cardiac digital subtraction angiography

International Nuclear Information System (INIS)

Gattoni, F.; Baldini, V.; Cairo, F.

1987-01-01

This paper reports the results of the ECG-gating in non-cardiac digital subtraction angiography (DSA). One hundred and fifteen patients underwent DSA (126 examinations); ECG-gating was applied in 66/126 examinations: images recorded at 70% of R wave were subtracted. Artifacts produced by vascular movements were evaluated in all patients: only 40 examinations, carried out whithout ECG-gating, showed vascular artifacts. The major advantage of the ECG-gated DSA is the more efficent subtraction because of the better images superimposition: therefore, ECG-gating can be clinically helpful. On the contrary, it could be a problem in arrhytmic or bradycardic patients. ECG-gating is helpful in DSA imaging of the thoracic and abdominal aorta and of the cervical and renal arteries. In the examinations of peripheral vessels of the limbs it is not so efficent as in the trunk or in the neck

Analysis of gate underlap channel double gate MOS transistor for electrical detection of bio-molecules

Science.gov (United States)

Ajay; Narang, Rakhi; Saxena, Manoj; Gupta, Mridula

2015-12-01

In this paper, an analytical model for gate drain underlap channel Double-Gate Metal-Oxide-Semiconductor Field-Effect Transistor (DG-MOSFET) for label free electrical detection of biomolecules has been proposed. The conformal mapping technique has been used to derive the expressions for surface potential, lateral electric field, energy bands (i.e. conduction and valence band) and threshold voltage (Vth). Subsequently a full drain current model to analyze the sensitivity of the biosensor has been developed. The shift in the threshold voltage and drain current (after the biomolecules interaction with the gate underlap channel region of the MOS transistor) has been used as a sensing metric. All the characteristic trends have been verified through ATLAS (SILVACO) device simulation results.

Gate A: changes to opening hours

CERN Multimedia

2015-01-01

Due to maintenance work, the opening hours of Gate A (near Reception) will be modified between Monday, 13 and Friday, 17 April 2015.   During this period, the gate will be open to vehicles between 7 a.m. and 9.30 a.m., then between 4.30 p.m. and 7 p.m. It will be completely closed to traffic between 9.30 a.m. and 4.30 p.m. Pedestrians and cyclists may continue to use the gate. We apologise for any inconvenience and thank you for your understanding.

Synthesis of multivalued quantum logic circuits by elementary gates

Science.gov (United States)

Di, Yao-Min; Wei, Hai-Rui

2013-01-01

We propose the generalized controlled X (gcx) gate as the two-qudit elementary gate, and based on Cartan decomposition, we also give the one-qudit elementary gates. Then we discuss the physical implementation of these elementary gates and show that it is feasible with current technology. With these elementary gates many important qudit quantum gates can be synthesized conveniently. We provide efficient methods for the synthesis of various kinds of controlled qudit gates and greatly simplify the synthesis of existing generic multi-valued quantum circuits. Moreover, we generalize the quantum Shannon decomposition (QSD), the most powerful technique for the synthesis of generic qubit circuits, to the qudit case. A comparison of ququart (d=4) circuits and qubit circuits reveals that using ququart circuits may have an advantage over the qubit circuits in the synthesis of quantum circuits.

Interpreting anomalies observed in oxide semiconductor TFTs under negative and positive bias stress

NARCIS (Netherlands)

Jin, J.W.; Nathan, A.; Barquinha, P.; Pereira, L.; Fortunato, E.; Martins, R.; Cobb, B.

2016-01-01

Oxide semiconductor thin-film transistors can show anomalous behavior under bias stress. Two types of anomalies are discussed in this paper. The first is the shift in threshold voltage (VTH) in a direction opposite to the applied bias stress, and highly dependent on gate dielectric material. We

Anesthetic pharmacology

National Research Council Canada - National Science Library

Evers, Alex S; Maze, M; Kharasch, Evan D

2011-01-01

...: Section 1 introduces the principles of drug action, Section 2 presents the molecular, cellular and integrated physiology of the target organ/functional system and Section 3 reviews the pharmacology...

Recruitment of aged donor heart with pharmacological stress echo. A case report

Directory of Open Access Journals (Sweden)

Bombardini Tonino

2006-01-01

Full Text Available Abstract Background The heart transplant is a treatment of the heart failure, which is not responding to medications, and its efficiency is already proved: unfortunately, organ donation is a limiting step of this life-saving procedure. To counteract heart donor shortage, we should screen aged potential donor hearts for initial cardiomyopathy and functionally significant coronary artery disease. Donors with a history of cardiac disease are generally excluded. Coronary angiography is recommended for most male donors older than 45 years and female donors older than 50 years to evaluate coronary artery stenoses. A simpler way to screen aged potential donor hearts for initial cardiomyopathy and functionally significant coronary artery disease should be stress echocardiography. Case report A marginal donor (A 57 year old woman meeting legal requirements for brain death underwent a transesophageal (TE Dipyridamole stress echo (6 minutes accelerated protocol to rule out moderate or severe heart and coronary artery disease. Wall motion was normal at baseline and at peak stress (WMSI = 1 at baseline and peak stress, without signs of stress inducible ischemia. The pressure/volume ratio was 9.6 mmHg/ml/m2 at baseline, increasing to 14 mmHg/ml/m2 at peak stress, demonstrating absence of latent myocardial dysfunction. The marginal donor heart was transplanted to a recipient "marginal" for co-morbidity ( a 63 year old man with multiple myeloma and cardiac amyloidosis , chronic severe heart failure, NYHA class IV. Postoperative treatment and early immunosuppressant regimen were performed according to standard protocols. The transplanted heart was assessed normal for dimensions and ventricular function at transthoracic (TT echocardiography on post-transplant day 7. Coronary artery disease was ruled out at coronary angiography one month after transplant; left ventriculography showed normal global and segmental LV function of the transplanted heart. Conclusion For

Multiple sclerosis: general features and pharmacologic approach

International Nuclear Information System (INIS)

Nielsen Lagumersindez, Denis; Martinez Sanchez, Gregorio

2009-01-01

Multiple sclerosis is an autoimmune, inflammatory and desmyelinization disease central nervous system (CNS) of unknown etiology and critical evolution. There different etiological hypotheses talking of a close interrelation among predisposing genetic factors and dissimilar environmental factors, able to give raise to autoimmune response at central nervous system level. Hypothesis of autoimmune pathogeny is based on study of experimental models, and findings in biopsies of affected patients by disease. Accumulative data report that the oxidative stress plays a main role in pathogenesis of multiple sclerosis. Oxygen reactive species generated by macrophages has been involved as mediators of demyelinization and of axon damage, in experimental autoimmune encephalomyelitis and strictly in multiple sclerosis. Disease diagnosis is difficult because of there is not a confirmatory unique test. Management of it covers the treatment of acute relapses, disease modification, and symptoms management. These features require an individualized approach, base on evolution of this affection, and tolerability of treatments. In addition to diet, among non-pharmacologic treatments for multiple sclerosis it is recommended physical therapy. Besides, some clinical assays have been performed in which we used natural extracts, nutrition supplements, and other agents with promising results. Pharmacology allowed neurologists with a broad array of proved effectiveness drugs; however, results of research laboratories in past years make probable that therapeutical possibilities increase notably in future. (Author)

Accuracy and Consistency of Respiratory Gating in Abdominal Cancer Patients

International Nuclear Information System (INIS)

Ge, Jiajia; Santanam, Lakshmi; Yang, Deshan; Parikh, Parag J.

2013-01-01

Purpose: To evaluate respiratory gating accuracy and intrafractional consistency for abdominal cancer patients treated with respiratory gated treatment on a regular linear accelerator system. Methods and Materials: Twelve abdominal patients implanted with fiducials were treated with amplitude-based respiratory-gated radiation therapy. On the basis of daily orthogonal fluoroscopy, the operator readjusted the couch position and gating window such that the fiducial was within a setup margin (fiducial-planning target volume [f-PTV]) when RPM indicated “beam-ON.” Fifty-five pre- and post-treatment fluoroscopic movie pairs with synchronized respiratory gating signal were recorded. Fiducial motion traces were extracted from the fluoroscopic movies using a template matching algorithm and correlated with f-PTV by registering the digitally reconstructed radiographs with the fluoroscopic movies. Treatment was determined to be “accurate” if 50% of the fiducial area stayed within f-PTV while beam-ON. For movie pairs that lost gating accuracy, a MATLAB program was used to assess whether the gating window was optimized, the external-internal correlation (EIC) changed, or the patient moved between movies. A series of safety margins from 0.5 mm to 3 mm was added to f-PTV for reassessing gating accuracy. Results: A decrease in gating accuracy was observed in 44% of movie pairs from daily fluoroscopic movies of 12 abdominal patients. Three main causes for inaccurate gating were identified as change of global EIC over time (∼43%), suboptimal gating setup (∼37%), and imperfect EIC within movie (∼13%). Conclusions: Inconsistent respiratory gating accuracy may occur within 1 treatment session even with a daily adjusted gating window. To improve or maintain gating accuracy during treatment, we suggest using at least a 2.5-mm safety margin to account for gating and setup uncertainties

High performance top-gated indium–zinc–oxide thin film transistors with in-situ formed HfO{sub 2} gate insulator

Energy Technology Data Exchange (ETDEWEB)

Song, Yang, E-mail: yang_song@brown.edu [Department of Physics, Brown University, 182 Hope Street, Providence, RI 02912 (United States); Zaslavsky, A. [Department of Physics, Brown University, 182 Hope Street, Providence, RI 02912 (United States); School of Engineering, Brown University, 184 Hope Street, Providence, RI 02912 (United States); Paine, D.C. [School of Engineering, Brown University, 184 Hope Street, Providence, RI 02912 (United States)

2016-09-01

We report on top-gated indium–zinc–oxide (IZO) thin film transistors (TFTs) with an in-situ formed HfO{sub 2} gate dielectric insulator. Building on our previous demonstration of high-performance IZO TFTs with Al{sub 2}O{sub 3}/HfO{sub 2} gate dielectric, we now report on a one-step process, in which Hf is evaporated onto the 20 nm thick IZO channel, forming a partially oxidized HfO{sub x} layer, without any additional insulator in-between. After annealing in air at 300 °C, the in-situ reaction between partially oxidized Hf and IZO forms a high quality HfO{sub 2} gate insulator with a low interface trapped charge density N{sub TC} ~ 2.3 × 10{sup 11} cm{sup −2} and acceptably low gate leakage < 3 × 10{sup −7} A/cm{sup 2} at gate voltage V{sub G} = 1 V. The annealed TFTs with gate length L{sub G} = 50 μm have high mobility ~ 95 cm{sup 2}/V ∙ s (determined via the Y-function technique), high on/off ratio ~ 10{sup 7}, near-zero threshold voltage V{sub T} = − 0.02 V, and a subthreshold swing of 0.062 V/decade, near the theoretical limit. The on-current of our proof-of-concept TFTs is relatively low, but can be improved by reducing L{sub G}, indicating that high-performance top-gated HfO{sub 2}-isolated IZO TFTs can be fabricated using a single-step in-situ dielectric formation approach. - Highlights: • High-performance indium–zinc–oxide (IZO) thin film transistors (TFTs). • Single-step in-situ dielectric formation approach simplifies fabrication process. • During anneal, reaction between HfO{sub x} and IZO channel forms a high quality HfO{sub 2} layer. • Gate insulator HfO{sub 2} shows low interface trapped charge and small gate leakage. • TFTs have high mobility, near-zero threshold voltage, and a low subthreshold swing.

A quantum Fredkin gate.

Science.gov (United States)

Patel, Raj B; Ho, Joseph; Ferreyrol, Franck; Ralph, Timothy C; Pryde, Geoff J

2016-03-01

Minimizing the resources required to build logic gates into useful processing circuits is key to realizing quantum computers. Although the salient features of a quantum computer have been shown in proof-of-principle experiments, difficulties in scaling quantum systems have made more complex operations intractable. This is exemplified in the classical Fredkin (controlled-SWAP) gate for which, despite theoretical proposals, no quantum analog has been realized. By adding control to the SWAP unitary, we use photonic qubit logic to demonstrate the first quantum Fredkin gate, which promises many applications in quantum information and measurement. We implement example algorithms and generate the highest-fidelity three-photon Greenberger-Horne-Zeilinger states to date. The technique we use allows one to add a control operation to a black-box unitary, something that is impossible in the standard circuit model. Our experiment represents the first use of this technique to control a two-qubit operation and paves the way for larger controlled circuits to be realized efficiently.

A quantum Fredkin gate

Science.gov (United States)

Patel, Raj B.; Ho, Joseph; Ferreyrol, Franck; Ralph, Timothy C.; Pryde, Geoff J.

2016-01-01

Minimizing the resources required to build logic gates into useful processing circuits is key to realizing quantum computers. Although the salient features of a quantum computer have been shown in proof-of-principle experiments, difficulties in scaling quantum systems have made more complex operations intractable. This is exemplified in the classical Fredkin (controlled-SWAP) gate for which, despite theoretical proposals, no quantum analog has been realized. By adding control to the SWAP unitary, we use photonic qubit logic to demonstrate the first quantum Fredkin gate, which promises many applications in quantum information and measurement. We implement example algorithms and generate the highest-fidelity three-photon Greenberger-Horne-Zeilinger states to date. The technique we use allows one to add a control operation to a black-box unitary, something that is impossible in the standard circuit model. Our experiment represents the first use of this technique to control a two-qubit operation and paves the way for larger controlled circuits to be realized efficiently. PMID:27051868

Characterization of a Common-Gate Amplifier Using Ferroelectric Transistors

Science.gov (United States)

Hunt, Mitchell; Sayyah, Rana; MacLeod, Todd C.; Ho, Fat D.

2011-01-01

In this paper, the empirical data collected through experiments performed using a FeFET in the common-gate amplifier circuit is presented. The FeFET common-gate amplifier was characterized by varying all parameters in the circuit, such as load resistance, biasing of the transistor, and input voltages. Due to the polarization of the ferroelectric layer, the particular behavior of the FeFET common-gate amplifier presents interesting results. Furthermore, the differences between a FeFET common-gate amplifier and a MOSFET common-gate amplifier are examined.

Bill Gates vil redde Folkeskolen

DEFF Research Database (Denmark)

Fejerskov, Adam Moe

2014-01-01

Det amerikanske uddannelsessystem bliver for tiden udsat for hård kritik, ledt an af Microsoft stifteren Bill Gates. Gates har indtil videre brugt 3 mia. kroner på at skabe opbakning til tiltag som præstationslønning af lærere og strømlining af pensum på tværs af alle skoler i landet...

Multi-Valued Logic Gates, Continuous Sensitivity, Reversibility, and Threshold Functions

OpenAIRE

İlhan, Aslı Güçlükan; Ünlü, Özgün

2016-01-01

We define an invariant of a multi-valued logic gate by considering the number of certain threshold functions associated with the gate. We call this invariant the continuous sensitivity of the gate. We discuss a method for analysing continuous sensitivity of a multi-valued logic gate by using experimental data about the gate. In particular, we will show that this invariant provides a lower bound for the sensitivity of a boolean function considered as a multi-valued logic gate. We also discuss ...

Normal p50 gating in unmedicated schizophrenia outpatients

DEFF Research Database (Denmark)

Arnfred, Sidse M; Chen, Andrew C.N.; Glenthøj, Birte Y

2003-01-01

The hypothesis of a sensory gating defect in schizophrenia has been supported by studies demonstrating deficient auditory P50 gating in patients. P50 gating is the relative attenuation of P50 amplitude in the auditory evoked potential following the second auditory stimulus of a stimulus pair....

Online junction temperature measurement using peak gate current

DEFF Research Database (Denmark)

Baker, Nick; Munk-Nielsen, Stig; Iannuzzo, Francesco

2015-01-01

A new method for junction temperature measurement of MOS-gated power semiconductor switches is presented. The measurement method involves detecting the peak voltage over the external gate resistor of an IGBT or MOSFET during turn-on. This voltage is directly proportional to the peak gate current...

Cytoplasmic Domains and Voltage-Dependent Potassium Channel Gating

Science.gov (United States)

Barros, Francisco; Domínguez, Pedro; de la Peña, Pilar

2012-01-01

The basic architecture of the voltage-dependent K+ channels (Kv channels) corresponds to a transmembrane protein core in which the permeation pore, the voltage-sensing components and the gating machinery (cytoplasmic facing gate and sensor–gate coupler) reside. Usually, large protein tails are attached to this core, hanging toward the inside of the cell. These cytoplasmic regions are essential for normal channel function and, due to their accessibility to the cytoplasmic environment, constitute obvious targets for cell-physiological control of channel behavior. Here we review the present knowledge about the molecular organization of these intracellular channel regions and their role in both setting and controlling Kv voltage-dependent gating properties. This includes the influence that they exert on Kv rapid/N-type inactivation and on activation/deactivation gating of Shaker-like and eag-type Kv channels. Some illustrative examples about the relevance of these cytoplasmic domains determining the possibilities for modulation of Kv channel gating by cellular components are also considered. PMID:22470342

Suppression of surface-originated gate lag by a dual-channel AlN/GaN high electron mobility transistor architecture

International Nuclear Information System (INIS)

Deen, David A.; Storm, David F.; Scott Katzer, D.; Bass, R.; Meyer, David J.

2016-01-01

A dual-channel AlN/GaN high electron mobility transistor (HEMT) architecture is demonstrated that leverages ultra-thin epitaxial layers to suppress surface-related gate lag. Two high-density two-dimensional electron gas (2DEG) channels are utilized in an AlN/GaN/AlN/GaN heterostructure wherein the top 2DEG serves as a quasi-equipotential that screens potential fluctuations resulting from distributed surface and interface states. The bottom channel serves as the transistor's modulated channel. Dual-channel AlN/GaN heterostructures were grown by molecular beam epitaxy on free-standing hydride vapor phase epitaxy GaN substrates. HEMTs fabricated with 300 nm long recessed gates demonstrated a gate lag ratio (GLR) of 0.88 with no degradation in drain current after bias stressed in subthreshold. These structures additionally achieved small signal metrics f_t/f_m_a_x of 27/46 GHz. These performance results are contrasted with the non-recessed gate dual-channel HEMT with a GLR of 0.74 and 82 mA/mm current collapse with f_t/f_m_a_x of 48/60 GHz.

Suppression of surface-originated gate lag by a dual-channel AlN/GaN high electron mobility transistor architecture

Energy Technology Data Exchange (ETDEWEB)

Deen, David A., E-mail: david.deen@alumni.nd.edu; Storm, David F.; Scott Katzer, D.; Bass, R.; Meyer, David J. [Naval Research Laboratory, Electronics Science and Technology Division, Washington, DC 20375 (United States)

2016-08-08

A dual-channel AlN/GaN high electron mobility transistor (HEMT) architecture is demonstrated that leverages ultra-thin epitaxial layers to suppress surface-related gate lag. Two high-density two-dimensional electron gas (2DEG) channels are utilized in an AlN/GaN/AlN/GaN heterostructure wherein the top 2DEG serves as a quasi-equipotential that screens potential fluctuations resulting from distributed surface and interface states. The bottom channel serves as the transistor's modulated channel. Dual-channel AlN/GaN heterostructures were grown by molecular beam epitaxy on free-standing hydride vapor phase epitaxy GaN substrates. HEMTs fabricated with 300 nm long recessed gates demonstrated a gate lag ratio (GLR) of 0.88 with no degradation in drain current after bias stressed in subthreshold. These structures additionally achieved small signal metrics f{sub t}/f{sub max} of 27/46 GHz. These performance results are contrasted with the non-recessed gate dual-channel HEMT with a GLR of 0.74 and 82 mA/mm current collapse with f{sub t}/f{sub max} of 48/60 GHz.

Automatically closing swing gate closure assembly

Science.gov (United States)

Chang, Shih-Chih; Schuck, William J.; Gilmore, Richard F.

1988-01-01

A swing gate closure assembly for nuclear reactor tipoff assembly wherein the swing gate is cammed open by a fuel element or spacer but is reliably closed at a desired closing rate primarily by hydraulic forces in the absence of a fuel charge.

Synthesizing biomolecule-based Boolean logic gates.

Science.gov (United States)

Miyamoto, Takafumi; Razavi, Shiva; DeRose, Robert; Inoue, Takanari

2013-02-15

One fascinating recent avenue of study in the field of synthetic biology is the creation of biomolecule-based computers. The main components of a computing device consist of an arithmetic logic unit, the control unit, memory, and the input and output devices. Boolean logic gates are at the core of the operational machinery of these parts, and hence to make biocomputers a reality, biomolecular logic gates become a necessity. Indeed, with the advent of more sophisticated biological tools, both nucleic acid- and protein-based logic systems have been generated. These devices function in the context of either test tubes or living cells and yield highly specific outputs given a set of inputs. In this review, we discuss various types of biomolecular logic gates that have been synthesized, with particular emphasis on recent developments that promise increased complexity of logic gate circuitry, improved computational speed, and potential clinical applications.

Synthesizing Biomolecule-based Boolean Logic Gates

Science.gov (United States)

Miyamoto, Takafumi; Razavi, Shiva; DeRose, Robert; Inoue, Takanari

2012-01-01

One fascinating recent avenue of study in the field of synthetic biology is the creation of biomolecule-based computers. The main components of a computing device consist of an arithmetic logic unit, the control unit, memory, and the input and output devices. Boolean logic gates are at the core of the operational machinery of these parts, hence to make biocomputers a reality, biomolecular logic gates become a necessity. Indeed, with the advent of more sophisticated biological tools, both nucleic acid- and protein-based logic systems have been generated. These devices function in the context of either test tubes or living cells and yield highly specific outputs given a set of inputs. In this review, we discuss various types of biomolecular logic gates that have been synthesized, with particular emphasis on recent developments that promise increased complexity of logic gate circuitry, improved computational speed, and potential clinical applications. PMID:23526588

Non-pharmacological management of abdominal pain-related functional gastrointestinal disorders in children.

Science.gov (United States)

Paul, Siba Prosad; Basude, Dharamveer

2016-11-01

Abdominal pain-related functional gastrointestinal disorder (AP-FGID) comprises of 4 main conditions: functional dyspepsia, irritable bowel syndrome, abdominal migraine and functional abdominal pain. AP-FGIDs are diagnosed clinically based on the Rome IV criteria for FGIDs of childhood. There is limited evidence for pharmacological therapies. This review article discusses nonpharmacological management of AP-FGID based on the current literature including systematic reviews, randomized controlled trials, cohort and case control studies. We aim to provide a comprehensive overview on the available evidence for the pediatricians and pediatric gastroenterologists involved in managing children with AP-FGID. Managing AP-FGIDs can be challenging. This should follow a stepwise approach with focused history, identification of "red flag" signs and symptoms, physical examination and investigations done following initial consultation. Family needs explaining that there is nothing seriously wrong with the child's abdomen. This explanation and reassurance can achieve symptom control in large number of cases. Non-pharmacological interventions are delivered through lifestyle and dietary changes and bio-psychosocial therapies. Dietary interventions vary depending on the type of AP-FGID. Bio-psychosocial therapies such as hypnotherapy, cognitive behavioral therapy and yoga aim at stress reduction. There is increasing evidence for use of non-pharmacological interventions in children with APFGID.

Exchange gate on the qudit space and Fock space

International Nuclear Information System (INIS)

Fujii, Kazuyuki

2003-01-01

We construct an exchange gate with small elementary gates on the space of qudits, which consist of three controlled shift gates and three 'reverse' gates. This is a natural extension of the qubit case. We also consider a similar situation in Fock space, but in this case we find some differences. However, we can construct the exchange gate by making use of a generalized coherent operator based on the Lie algebra su(2), which is a well-known method in quantum optics. We also make a brief comment on 'imperfect clones'

Dry dock gate stability modelling

Science.gov (United States)

Oktoberty; Widiyanto; Sasono, E. J.; Pramono, S.; Wandono, A. T.

2018-03-01

The development of marine transportation needs in Indonesia increasingly opens national shipyard business opportunities to provide shipbuilding services to the shipbuilding vessels. That emphasizes the stability of prime. The ship's decking door becomes an integral part of the efficient place and the specification of the use of the asset of its operational ease. This study aims to test the stability of Dry Dock gate with the length of 35.4 meters using Maxsurf and Hydromax in analyzing the calculation were in its assessment using interval per 500 mm length so that it can get detail data toward longitudinal and transverse such as studying Ship planning in general. The test result shows dry dock gate meets IMO standard with ballast construction containing 54% and 68% and using fix ballast can produce GMt 1,924 m, tide height 11,357m. The GMt value indicates dry dick gate can be stable and firmly erect at the base of the mouth dry dock. When empty ballast produces GMt 0.996 which means dry dock date is stable, but can easily be torn down. The condition can be used during dry dock gate treatment.

Robust Deterministic Controlled Phase-Flip Gate and Controlled-Not Gate Based on Atomic Ensembles Embedded in Double-Sided Optical Cavities

Science.gov (United States)

Liu, A.-Peng; Cheng, Liu-Yong; Guo, Qi; Zhang, Shou

2018-02-01

We first propose a scheme for controlled phase-flip gate between a flying photon qubit and the collective spin wave (magnon) of an atomic ensemble assisted by double-sided cavity quantum systems. Then we propose a deterministic controlled-not gate on magnon qubits with parity-check building blocks. Both the gates can be accomplished with 100% success probability in principle. Atomic ensemble is employed so that light-matter coupling is remarkably improved by collective enhancement. We assess the performance of the gates and the results show that they can be faithfully constituted with current experimental techniques.

Calibration of submerged multi-sluice gates

Directory of Open Access Journals (Sweden)

Mohamed F. Sauida

2014-09-01

The main objective of this work is to study experimentally and verify empirically the different parameters affecting the discharge through submerged multiple sluice gates (i.e., the expansion ratios, gates operational management, etc.. Using multiple regression analysis of the experimental results, a general equation for discharge coefficient is developed. The results show, that the increase in the expansion ratio and the asymmetric operation of gates, give higher values for the discharge coefficient. The obtained predictions of the discharge coefficient using the developed equations are compared to the experimental data. The present developed equations showed good consistency and high accuracy.

A double-gate double-feedback JFET charge-sensitive preamplifier

International Nuclear Information System (INIS)

Fazzi, A.

1996-01-01

A new charge-sensitive preamplifier (CSP) without a physical resistance in the feedback is presented. The input device has to be a double-gate JFET. In this new preamplifier configuration the feedback capacitor is continuously discharged by means of a second DC current feedback loop closed through the bottom gate of the input JFET. The top gate-channel junction works as usual in reverse bias, the bottom gate-channel is forward biased. A fraction of the current injected by the bottom gate reaches the top gate discharging the feedback capacitor. The n-channel double-gate JFET is considered from the viewpoint of the restoring action as a parasitic p-n-p ''transversal'' bipolar junction transistor. The new preamplifier is also suited for detectors operating at room temperature with leakage current which may vary with time. The DC behaviour and the dynamic behaviour of the circuit is analyzed and new measurements presented. (orig.)

Deep Gate Recurrent Neural Network

Science.gov (United States)

2016-11-22

and Fred Cummins. Learning to forget: Continual prediction with lstm . Neural computation, 12(10):2451–2471, 2000. Alex Graves. Generating sequences...DSGU) and Simple Gated Unit (SGU), which are structures for learning long-term dependencies. Compared to traditional Long Short-Term Memory ( LSTM ) and...Gated Recurrent Unit (GRU), both structures require fewer parameters and less computation time in sequence classification tasks. Unlike GRU and LSTM

Neuropathic pain in people with cancer (part 2): pharmacological and non-pharmacological management.

Science.gov (United States)

Taverner, Tarnia

2015-08-01

The aim of this paper is to provide an overview of the management of neuropathic pain associated with cancer and to provide helpful clinical advice for nurses working with patients who may have neuropathic pain. While cancer pain is a mixed-mechanism pain, this article will focus only on neuropathic pain management. The impact of neuropathic pain on patients' quality of life is great and while many patients recover from their cancer, a significant number continue to suffer from a neuropathic pain syndrome. Management of neuropathic pain is significantly different from management of nociceptive pain with respect to pharmacological and non-pharmacological strategies. Neuropathic pain is complex, and as such requires complex management using pharmacological as well as non-pharmacological approaches. Specific drugs for neuropathic pain may be effective for some patients, but not all; therefore, ongoing and comprehensive assessment and management are required. Furthermore, these patients may require trials of several drugs before they find one that works for them. It is important for nurses to understand neuropathic pain, its manifestation, impact on quality of life and management when nursing patients with neuropathic pain associated with cancer.

Natural product-derived pharmacological modulators of Nrf2/ARE pathway for chronic diseases.

Science.gov (United States)

Kumar, Hemant; Kim, In-Su; More, Sandeep Vasant; Kim, Byung-Wook; Choi, Dong-Kug

2014-01-01

Covering: 2000 to 2013. Oxidative stress is the central component of chronic diseases. The nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) pathway is vital in the up-regulation of cytoprotective genes and enzymes in response to oxidative stress and treatment with certain dietary phytochemicals. Herein, we classify bioactive compounds derived from natural products that are Nrf2/ARE pathway activators and recapitulate the molecular mechanisms for inducing Nrf2 to provide favorable effects in experimental models of chronic diseases. Moreover, pharmacological inhibition of Nrf2 signalling has emerged as promising strategy against multi-drug resistance thereby improving the treatment efficacy. We have also enlisted natural product-derived inhibitors of Nrf2/ARE pathway.

Posttraumatic Stress Disorder Disturbs Coronary Tone and Its Regulatory Mechanisms.

Science.gov (United States)

Lazuko, Svetlana S; Kuzhel, Olga P; Belyaeva, Lyudmila E; Manukhina, Eugenia B; Fred Downey, H; Tseilikman, Olga B; Komelkova, Maria V; Tseilikman, Vadim E

2018-01-01

Posttraumatic stress disorder (PTSD) is associated with myocardial injury, but changes in coronary regulatory mechanisms in PTSD have not been investigated. This study evaluated the effect of PTSD-inducing stress on coronary tone and its regulation by nitric oxide (NO) and voltage-gated K + channels. PTSD was induced by exposing rats to predator stress, 15 min daily for 10 days, followed by 14 stress-free days. Presence of PTSD was confirmed by the elevated plus-maze test. Coronary tone was evaluated from changes in coronary perfusion pressure of Langendorff isolated hearts. Predator stress induced significant decreases in coronary tone of isolated hearts and in blood pressure of intact rats. L-NAME, a non-selective NO synthase (NOS) inhibitor, but not S-MT, a selective iNOS inhibitor, and increased coronary tone of control rats. In PTSD rats, both L-NAME and S-MT increased coronary tone. Therefore, the stress-induced coronary vasodilation resulted from NO overproduction by both iNOS and eNOS. NOS induction was apparently due to systemic inflammation as evidenced by increased serum interleukin-1β and C-reactive protein in PTSD rats. Decreased corticosterone in PTSD rats may have contributed to inflammation and its effect on coronary tone. PTSD was also associated with voltage-gated K + channel dysfunction, which would have also reduced coronary tone.

Aralia elata var. mandshurica (Rupr. & Maxim.) J.Wen: An overview of pharmacological studies.

Science.gov (United States)

Shikov, Alexander N; Pozharitskaya, Olga N; Makarov, Valery G

2016-11-15

Aralia elata var. mandshurica (Rupr. & Maxim.) J.Wen syn. A. mandshurica Rupr. & Maxim is evaluated for its medicinal application. The aim of this study is to analyze pharmacological studies on A. elata var. mandshurica published until December 2015. The information regarding the chemistry, safety, effectiveness, and pharmacological and clinical effects of A. elata was systematically collected from the scientific literature through library catalogs; online services such as E-library.ru, Medline/PubMed, Scopus, Web of Science, and Google Scholar. A. elata is often considered an example of a medicinal plant used in Chinese, Korean, and Japanese traditional medicine. However, the contemporary applications of Aralia in officinal medicine result primarily from a large number of pharmacological and clinical investigations carried out in the former USSR in the mid-20th century. Since the 1950s, medicinal preparations from radices of A. elata and radices of A. mandshurica have secured an established position within Russian/USSR medicine as evidenced by the inclusion of the drug in recent editions of the National Pharmacopoeia of the USSR and in the Register of Medicinal Preparations of Russia. Pharmacological studies on animals have shown that Aralia increases physical working capacity and affords a stress-protective effect against a broad spectrum of harmful factors including cold stress, immobilization, UV irradiation, and low air pressure. The phytoadaptogen exerts an effect on the central nervous, reproductive, immune, respiratory, and gastrointestinal systems; the metabolic syndrome including hypolipidemic and antidiabetic effects; and blood coagulation. Together with general properties of adaptogens, Aralia has its own specificity, which manifests in cardioprotective and antiarrhythmic activities. Studies on isolated organs, cells, and enzymes have revealed that Aralia preparations exhibit antioxidant activities and enhance sarcoplasmic reticulum Ca 2+ -ATPase

Hot carrier injection degradation under dynamic stress

International Nuclear Information System (INIS)

Ma Xiao-Hua; Cao Yan-Rong; Hao Yue; Zhang Yue

2011-01-01

In this paper, we have studied hot carrier injection (HCI) under alternant stress. Under different stress modes, different degradations are obtained from the experiment results. The different alternate stresses can reduce or enhance the HC effect, which mainly depends on the latter condition of the stress cycle. In the stress mode A (DC stress with electron injection), the degradation keeps increasing. In the stress modes B (DC stress and then stress with the smallest gate injection) and C (DC stress and then stress with hole injection under V g = 0 V and V d = 1.8 V), recovery appears in the second stress period. And in the stress mode D (DC stress and then stress with hole injection under V g = −1.8 V and V d = 1.8 V), as the traps filled in by holes can be smaller or greater than the generated interface states, the continued degradation or recovery in different stress periods can be obtained. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Error-Transparent Quantum Gates for Small Logical Qubit Architectures

Science.gov (United States)

Kapit, Eliot

2018-02-01

One of the largest obstacles to building a quantum computer is gate error, where the physical evolution of the state of a qubit or group of qubits during a gate operation does not match the intended unitary transformation. Gate error stems from a combination of control errors and random single qubit errors from interaction with the environment. While great strides have been made in mitigating control errors, intrinsic qubit error remains a serious problem that limits gate fidelity in modern qubit architectures. Simultaneously, recent developments of small error-corrected logical qubit devices promise significant increases in logical state lifetime, but translating those improvements into increases in gate fidelity is a complex challenge. In this Letter, we construct protocols for gates on and between small logical qubit devices which inherit the parent device's tolerance to single qubit errors which occur at any time before or during the gate. We consider two such devices, a passive implementation of the three-qubit bit flip code, and the author's own [E. Kapit, Phys. Rev. Lett. 116, 150501 (2016), 10.1103/PhysRevLett.116.150501] very small logical qubit (VSLQ) design, and propose error-tolerant gate sets for both. The effective logical gate error rate in these models displays superlinear error reduction with linear increases in single qubit lifetime, proving that passive error correction is capable of increasing gate fidelity. Using a standard phenomenological noise model for superconducting qubits, we demonstrate a realistic, universal one- and two-qubit gate set for the VSLQ, with error rates an order of magnitude lower than those for same-duration operations on single qubits or pairs of qubits. These developments further suggest that incorporating small logical qubits into a measurement based code could substantially improve code performance.

Diminished auditory sensory gating during active auditory verbal hallucinations.

Science.gov (United States)

Thoma, Robert J; Meier, Andrew; Houck, Jon; Clark, Vincent P; Lewine, Jeffrey D; Turner, Jessica; Calhoun, Vince; Stephen, Julia

2017-10-01

Auditory sensory gating, assessed in a paired-click paradigm, indicates the extent to which incoming stimuli are filtered, or "gated", in auditory cortex. Gating is typically computed as the ratio of the peak amplitude of the event related potential (ERP) to a second click (S2) divided by the peak amplitude of the ERP to a first click (S1). Higher gating ratios are purportedly indicative of incomplete suppression of S2 and considered to represent sensory processing dysfunction. In schizophrenia, hallucination severity is positively correlated with gating ratios, and it was hypothesized that a failure of sensory control processes early in auditory sensation (gating) may represent a larger system failure within the auditory data stream; resulting in auditory verbal hallucinations (AVH). EEG data were collected while patients (N=12) with treatment-resistant AVH pressed a button to indicate the beginning (AVH-on) and end (AVH-off) of each AVH during a paired click protocol. For each participant, separate gating ratios were computed for the P50, N100, and P200 components for each of the AVH-off and AVH-on states. AVH trait severity was assessed using the Psychotic Symptoms Rating Scales AVH Total score (PSYRATS). The results of a mixed model ANOVA revealed an overall effect for AVH state, such that gating ratios were significantly higher during the AVH-on state than during AVH-off for all three components. PSYRATS score was significantly and negatively correlated with N100 gating ratio only in the AVH-off state. These findings link onset of AVH with a failure of an empirically-defined auditory inhibition system, auditory sensory gating, and pave the way for a sensory gating model of AVH. Copyright © 2017 Elsevier B.V. All rights reserved.

Interprofessional education in pharmacology using high-fidelity simulation.

Science.gov (United States)

Meyer, Brittney A; Seefeldt, Teresa M; Ngorsuraches, Surachat; Hendrickx, Lori D; Lubeck, Paula M; Farver, Debra K; Heins, Jodi R

2017-11-01

This study examined the feasibility of an interprofessional high-fidelity pharmacology simulation and its impact on pharmacy and nursing students' perceptions of interprofessionalism and pharmacology knowledge. Pharmacy and nursing students participated in a pharmacology simulation using a high-fidelity patient simulator. Faculty-facilitated debriefing included discussion of the case and collaboration. To determine the impact of the activity on students' perceptions of interprofessionalism and their ability to apply pharmacology knowledge, surveys were administered to students before and after the simulation. Attitudes Toward Health Care Teams scale (ATHCT) scores improved from 4.55 to 4.72 on a scale of 1-6 (p = 0.005). Almost all (over 90%) of the students stated their pharmacology knowledge and their ability to apply that knowledge improved following the simulation. A simulation in pharmacology is feasible and favorably affected students' interprofessionalism and pharmacology knowledge perceptions. Pharmacology is a core science course required by multiple health professions in early program curricula, making it favorable for incorporation of interprofessional learning experiences. However, reports of high-fidelity interprofessional simulation in pharmacology courses are limited. This manuscript contributes to the literature in the field of interprofessional education by demonstrating that an interprofessional simulation in pharmacology is feasible and can favorably affect students' perceptions of interprofessionalism. This manuscript provides an example of a pharmacology interprofessional simulation that faculty in other programs can use to build similar educational activities. Copyright © 2017 Elsevier Inc. All rights reserved.

Applications of stable isotopes in clinical pharmacology

NARCIS (Netherlands)

Schellekens, Reinout C A; Stellaard, Frans; Woerdenbag, Herman J; Frijlink, Henderik W; Kosterink, Jos G W

2011-01-01

This review aims to present an overview of the application of stable isotope technology in clinical pharmacology. Three main categories of stable isotope technology can be distinguished in clinical pharmacology. Firstly, it is applied in the assessment of drug pharmacology to determine the

Feasibility of epicardial adipose tissue quantification in non-ECG-gated low-radiation-dose CT: comparison with prospectively ECG-gated cardiac CT

Energy Technology Data Exchange (ETDEWEB)

Simon-Yarza, Isabel; Viteri-Ramirez, Guillermo; Saiz-Mendiguren, Ramon; Slon-Roblero, Pedro J.; Paramo, Maria [Dept. of Radiology, Clinica Univ. de Navarra, Pamplona (Spain); Bastarrika, Gorka [Dept. of Radiology, Clinica Univ. de Navarra, Pamplona (Spain); Cardiac Imaging Unit, Clinica Univ. de Navarra, Pamplona (Spain)], e-mail: bastarrika@unav.es

2012-06-15

Background: Epicardial adipose tissue (EAT) is an important indicator of cardiovascular risk. This parameter is generally assessed on ECG-gated computed tomography (CT) images. Purpose: To evaluate feasibility and reliability of EAT quantification on non-gated thoracic low-radiation-dose CT examinations with respect to prospectively ECG-gated cardiac CT acquisition. Material and Methods: Sixty consecutive asymptomatic smokers (47 men; mean age 64 {+-} 9.8 years) underwent low-dose CT of the chest and prospectively ECG-gated cardiac CT acquisitions (64-slice dual-source CT). The two examinations were reconstructed with the same range, field of view, slice thickness, and convolution algorithm. Two independent observers blindly quantified EAT volume using commercially available software. Data were compared with paired sample Student t-test, concordance correlation coefficients (CCC), and Bland-Altman plots. Results: No statistically significant difference was observed for EAT volume quantification with low-dose-CT (141.7 {+-} 58.3 mL) with respect to ECG-gated CT (142.7 {+-} 57.9 mL). Estimation of CCC showed almost perfect concordance between the two techniques for EAT-volume assessment (CCC, 0.99; mean difference, 0.98 {+-} 5.1 mL). Inter-observer agreement for EAT volume estimation was CCC: 0.96 for low-dose-CT examinations and 0.95 for ECG-gated CT. Conclusion: Non-gated low-dose CT allows quantifying EAT with almost the same concordance and reliability as using dedicated prospectively ECG-gated cardiac CT acquisition protocols.

Feasibility of epicardial adipose tissue quantification in non-ECG-gated low-radiation-dose CT: comparison with prospectively ECG-gated cardiac CT

International Nuclear Information System (INIS)

Simon-Yarza, Isabel; Viteri-Ramirez, Guillermo; Saiz-Mendiguren, Ramon; Slon-Roblero, Pedro J.; Paramo, Maria; Bastarrika, Gorka

2012-01-01

Background: Epicardial adipose tissue (EAT) is an important indicator of cardiovascular risk. This parameter is generally assessed on ECG-gated computed tomography (CT) images. Purpose: To evaluate feasibility and reliability of EAT quantification on non-gated thoracic low-radiation-dose CT examinations with respect to prospectively ECG-gated cardiac CT acquisition. Material and Methods: Sixty consecutive asymptomatic smokers (47 men; mean age 64 ± 9.8 years) underwent low-dose CT of the chest and prospectively ECG-gated cardiac CT acquisitions (64-slice dual-source CT). The two examinations were reconstructed with the same range, field of view, slice thickness, and convolution algorithm. Two independent observers blindly quantified EAT volume using commercially available software. Data were compared with paired sample Student t-test, concordance correlation coefficients (CCC), and Bland-Altman plots. Results: No statistically significant difference was observed for EAT volume quantification with low-dose-CT (141.7 ± 58.3 mL) with respect to ECG-gated CT (142.7 ± 57.9 mL). Estimation of CCC showed almost perfect concordance between the two techniques for EAT-volume assessment (CCC, 0.99; mean difference, 0.98 ± 5.1 mL). Inter-observer agreement for EAT volume estimation was CCC: 0.96 for low-dose-CT examinations and 0.95 for ECG-gated CT. Conclusion: Non-gated low-dose CT allows quantifying EAT with almost the same concordance and reliability as using dedicated prospectively ECG-gated cardiac CT acquisition protocols

Dual material gate doping-less tunnel FET with hetero gate dielectric for enhancement of analog/RF performance

Science.gov (United States)

Anand, Sunny; Sarin, R. K.

2017-02-01

In this paper, charge-plasma-based tunnel FET is proposed by employing dual material gate with hetero gate dielectric technique and it is named hetero-dielectric dual material gate doping-less TFET (HD_DMG_DLTFET). It is compared with conventional doping-less TFET (DLTFET) and dual material gate doping-less TFET (DMG_DLTFET) on the basis of analog and RF performance. The HD_DMG_DLTFET provides better ON state current ({I}\\text{ON}=94 μ \\text{A}/μ \\text{m}), {I}\\text{ON}/{I}\\text{OFF}(≈ 1.36× {10}13), \\text{point} (≈ 3\\text{mV}/\\text{dec}) and average subthreshold slope (\\text{AV}-\\text{SS}=40.40 \\text{mV}/\\text{dec}). The proposed device offers low total gate capacitance (C gg) along with higher drive current. However, with a better transconductance (g m) and cut-off frequency (f T), the HD_DMG_DLTFET can be a good candidate for RF circuitry. The early voltage (V EA) and output conductance (g d) are also moderate for the proposed device with comparison to other devices and therefore can be a candidate for analog devices. From all these simulation results and their study, it is observed that HD_DMG_DLTFET has improved analog/RF performance compared to DLTFET and DMG_DLTFET.

Hybrid Toffoli gate on photons and quantum spins.

Science.gov (United States)

Luo, Ming-Xing; Ma, Song-Ya; Chen, Xiu-Bo; Wang, Xiaojun

2015-11-16

Quantum computation offers potential advantages in solving a number of interesting and difficult problems. Several controlled logic gates, the elemental building blocks of quantum computer, have been realized with various physical systems. A general technique was recently proposed that significantly reduces the realization complexity of multiple-control logic gates by harnessing multi-level information carriers. We present implementations of a key quantum circuit: the three-qubit Toffoli gate. By exploring the optical selection rules of one-sided optical microcavities, a Toffoli gate may be realized on all combinations of photon and quantum spins in the QD-cavity. The three general controlled-NOT gates are involved using an auxiliary photon with two degrees of freedom. Our results show that photons and quantum spins may be used alternatively in quantum information processing.

Extending Double Optical Gating to the Midinfrared

Science.gov (United States)

Gorman, Timothy; Camper, Antoine; Agostini, Pierre; Dimauro, Louis

2015-05-01

In the past decade there has been great interest in creating broadband isolated attosecond pulses (IAPs). Primarily these IAPs have been generated using Ti:Sapphire 800nm short pulses, namely through spatiotemporal gating with the attosecond lighthouse technique, amplitude gating, polarization gating, and double optical gating (DOG). Here we present theoretical calculations and experimental investigations into extending DOG to using a 2 μm driving wavelength, the benefits of which include extended harmonic cutoff and longer input driving pulse durations. It is proposed that broadband IAPs with cutoffs extending up to 250 eV can be generated in Argon by using >30 fs pulses from the passively-CEP stabilized 2 μm idler out of an optical parametric amplifier combined with a collinear DOG experimental setup.

Seven channel gated charge to time converter

Energy Technology Data Exchange (ETDEWEB)

Stubbs, R J; Waddoup, W D [Durham Univ. (UK)

1977-11-01

By using a hybrid integrated circuit seven independent gated charge to time converters have been constructed in a single width NIM module. Gate widths from < approximately 10 ns to approximately 300 ns are possible with a resolution of 0.25 pC, linearity is better than +-1 pC over 2.5 decades of input signal height. Together with a multichannel scaling system described in the following paper one has a very powerful multichannel gated ADC system.

Toxicological and pharmacological concerns on oxidative stress and related diseases

Energy Technology Data Exchange (ETDEWEB)

Saeidnia, Soodabeh [Medicinal Plants Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran 1417614411 (Iran, Islamic Republic of); College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon (Canada); Abdollahi, Mohammad, E-mail: Mohammad@TUMS.Ac.Ir [Department of Toxicology and Pharmacology, Faculty of Pharmacy, Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran 1417614411 (Iran, Islamic Republic of)

2013-12-15

Although reactive oxygen species (ROS) such as superoxide, hydrogen peroxide and hydroxyl radical are generated as the natural byproduct of normal oxygen metabolism, they can create oxidative damage via interaction with bio-molecules. The role of oxidative stress as a remarkable upstream part is frequently reported in the signaling cascade of inflammation as well as chemo attractant production. Even though hydrogen peroxide can control cell signaling and stimulate cell proliferation at low levels, in higher concentrations it can initiate apoptosis and in very high levels may create necrosis. So far, the role of ROS in cellular damage and death is well documented with implicating in a broad range of degenerative alterations e.g. carcinogenesis, aging and other oxidative stress related diseases (OSRDs). Reversely, it is cleared that antioxidants are potentially able to suppress (at least in part) the immune system and to enhance the normal cellular protective responses to tissue damage. In this review, we aimed to provide insights on diverse OSRDs, which are correlated with the concept of oxidative stress as well as its cellular effects that can be inhibited by antioxidants. Resveratrol, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, statins, nebivolol and carvedilol, pentaerythritol tetranitrate, mitochondria-targeted antioxidants, and plant-derived drugs (alone or combined) are the potential medicines that can be used to control OSRD.

Toxicological and pharmacological concerns on oxidative stress and related diseases

International Nuclear Information System (INIS)

Saeidnia, Soodabeh; Abdollahi, Mohammad

2013-01-01

Although reactive oxygen species (ROS) such as superoxide, hydrogen peroxide and hydroxyl radical are generated as the natural byproduct of normal oxygen metabolism, they can create oxidative damage via interaction with bio-molecules. The role of oxidative stress as a remarkable upstream part is frequently reported in the signaling cascade of inflammation as well as chemo attractant production. Even though hydrogen peroxide can control cell signaling and stimulate cell proliferation at low levels, in higher concentrations it can initiate apoptosis and in very high levels may create necrosis. So far, the role of ROS in cellular damage and death is well documented with implicating in a broad range of degenerative alterations e.g. carcinogenesis, aging and other oxidative stress related diseases (OSRDs). Reversely, it is cleared that antioxidants are potentially able to suppress (at least in part) the immune system and to enhance the normal cellular protective responses to tissue damage. In this review, we aimed to provide insights on diverse OSRDs, which are correlated with the concept of oxidative stress as well as its cellular effects that can be inhibited by antioxidants. Resveratrol, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, statins, nebivolol and carvedilol, pentaerythritol tetranitrate, mitochondria-targeted antioxidants, and plant-derived drugs (alone or combined) are the potential medicines that can be used to control OSRD

Comparison of short-circuit characteristics of trench gate and planar gate U-shaped channel SOI-LIGBTs

Science.gov (United States)

Zhang, Long; Zhu, Jing; Sun, Weifeng; Zhao, Minna; Huang, Xuequan; Chen, Jiajun; Shi, Longxing; Chen, Jian; Ding, Desheng

2017-09-01

Comparison of short-circuit (SC) characteristics of 500 V rated trench gate U-shaped channel (TGU) SOI-LIGBT and planar gate U-shaped channel (PGU) SOI-LIGBT is made for the first time in this paper. The on-state carrier profile of the TGU structure is reshaped by the dual trenches (a gate trench G1 and a hole barrier trench G2), which leads to a different conduction behavior from that of the PGU structure. The TGU structure exhibits a higher latchup immunity but a severer self-heating effect. At current density (JC) 640 A/cm2. Comparison of layouts and fabrication processes are also made between the two types of devices.

Probing Dense Sprays with Gated, Picosecond, Digital Particle Field Holography

Directory of Open Access Journals (Sweden)

James Trolinger

2011-12-01

Full Text Available This paper describes work that demonstrated the feasibility of producing a gated digital holography system that is capable of producing high-resolution images of three-dimensional particle and structure details deep within dense particle fields of a spray. We developed a gated picosecond digital holocamera, using optical Kerr cell gating, to demonstrate features of gated digital holography that make it an exceptional candidate for this application. The Kerr cell gate shuttered the camera after the initial burst of ballistic and snake photons had been recorded, suppressing longer path, multiple scattered illumination. By starting with a CW laser without gating and then incorporating a picosecond laser and an optical Kerr gate, we were able to assess the imaging quality of the gated holograms, and determine improvement gained by gating. We produced high quality images of 50–200 μm diameter particles, hairs and USAF resolution charts from digital holograms recorded through turbid media where more than 98% of the light was scattered from the field. The system can gate pulses as short as 3 mm in pathlength (10 ps, enabling image-improving features of the system. The experiments lead us to the conclusion that this method has an excellent capability as a diagnostics tool in dense spray combustion research.

Free energy dissipation of the spontaneous gating of a single voltage-gated potassium channel.

Science.gov (United States)

Wang, Jia-Zeng; Wang, Rui-Zhen

2018-02-01

Potassium channels mainly contribute to the resting potential and re-polarizations, with the potassium electrochemical gradient being maintained by the pump Na + /K + -ATPase. In this paper, we construct a stochastic model mimicking the kinetics of a potassium channel, which integrates temporal evolving of the membrane voltage and the spontaneous gating of the channel. Its stationary probability density functions (PDFs) are found to be singular at the boundaries, which result from the fact that the evolving rates of voltage are greater than the gating rates of the channel. We apply PDFs to calculate the power dissipations of the potassium current, the leakage, and the gating currents. On a physical perspective, the essential role of the system is the K + -battery charging the leakage (L-)battery. A part of power will inevitably be dissipated among the process. So, the efficiency of energy transference is calculated.

Free energy dissipation of the spontaneous gating of a single voltage-gated potassium channel

Science.gov (United States)

Wang, Jia-Zeng; Wang, Rui-Zhen

2018-02-01

Potassium channels mainly contribute to the resting potential and re-polarizations, with the potassium electrochemical gradient being maintained by the pump Na+/K+-ATPase. In this paper, we construct a stochastic model mimicking the kinetics of a potassium channel, which integrates temporal evolving of the membrane voltage and the spontaneous gating of the channel. Its stationary probability density functions (PDFs) are found to be singular at the boundaries, which result from the fact that the evolving rates of voltage are greater than the gating rates of the channel. We apply PDFs to calculate the power dissipations of the potassium current, the leakage, and the gating currents. On a physical perspective, the essential role of the system is the K+-battery charging the leakage (L-)battery. A part of power will inevitably be dissipated among the process. So, the efficiency of energy transference is calculated.

A gating grid driver for time projection chambers

Energy Technology Data Exchange (ETDEWEB)

Tangwancharoen, S.; Lynch, W.G.; Barney, J.; Estee, J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Shane, R. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Tsang, M.B., E-mail: tsang@nscl.msu.edu [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Zhang, Y. [Department of Physics, Tsinghua University, Beijing 100084 (China); Isobe, T.; Kurata-Nishimura, M. [RIKEN Nishina Center, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Murakami, T. [Department of Physics, Kyoto University, Kita-shirakawa, Kyoto 606–8502 (Japan); Xiao, Z.G. [Department of Physics, Tsinghua University, Beijing 100084 (China); Zhang, Y.F. [College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China)

2017-05-01

A simple but novel driver system has been developed to operate the wire gating grid of a Time Projection Chamber (TPC). This system connects the wires of the gating grid to its driver via low impedance transmission lines. When the gating grid is open, all wires have the same voltage allowing drift electrons, produced by the ionization of the detector gas molecules, to pass through to the anode wires. When the grid is closed, the wires have alternating higher and lower voltages causing the drift electrons to terminate at the more positive wires. Rapid opening of the gating grid with low pickup noise is achieved by quickly shorting the positive and negative wires to attain the average bias potential with N-type and P-type MOSFET switches. The circuit analysis and simulation software SPICE shows that the driver restores the gating grid voltage to 90% of the opening voltage in less than 0.20 µs, for small values of the termination resistors. When tested in the experimental environment of a time projection chamber larger termination resistors were chosen so that the driver opens the gating grid in 0.35 µs. In each case, opening time is basically characterized by the RC constant given by the resistance of the switches and terminating resistors and the capacitance of the gating grid and its transmission line. By adding a second pair of N-type and P-type MOSFET switches, the gating grid is closed by restoring 99% of the original charges to the wires within 3 µs.

Programming the quorum sensing-based AND gate in Shewanella oneidensis for logic gated-microbial fuel cells.

Science.gov (United States)

Hu, Yidan; Yang, Yun; Katz, Evgeny; Song, Hao

2015-03-11

An AND logic gate based on a synthetic quorum-sensing (QS) module was constructed in a Shewanella oneidensis MR-1 mtrA knockout mutant. The presence of two input signals activated the expression of a periplasmic decaheme cytochrome MtrA to regenerate the extracellular electron transfer conduit, enabling the construction of AND-gated microbial fuel cells.

ZnO nanowire-based nano-floating gate memory with Pt nanocrystals embedded in Al2O3 gate oxides

International Nuclear Information System (INIS)

Yeom, Donghyuk; Kang, Jeongmin; Lee, Myoungwon; Jang, Jaewon; Yun, Junggwon; Jeong, Dong-Young; Yoon, Changjoon; Koo, Jamin; Kim, Sangsig

2008-01-01

The memory characteristics of ZnO nanowire-based nano-floating gate memory (NFGM) with Pt nanocrystals acting as the floating gate nodes were investigated in this work. Pt nanocrystals were embedded between Al 2 O 3 tunneling and control oxide layers deposited on ZnO nanowire channels. For a representative ZnO nanowire-based NFGM with embedded Pt nanocrystals, a threshold voltage shift of 3.8 V was observed in its drain current versus gate voltage (I DS -V GS ) measurements for a double sweep of the gate voltage, revealing that the deep effective potential wells built into the nanocrystals provide our NFGM with a large charge storage capacity. Details of the charge storage effect observed in this memory device are discussed in this paper

Stress and visceral pain: from animal models to clinical therapies

Science.gov (United States)

Larauche, Muriel; Mulak, Agata; Taché, Yvette

2011-01-01

Epidemiological studies have implicated stress (psychosocial and physical) as a trigger of first onset or exacerbation of irritable bowel syndrome (IBS) symptoms of which visceral pain is an integrant landmark. A number of experimental acute or chronic exteroceptive or interoceptive stressors induce visceral hyperalgesia in rodents although recent evidence also points to stress-related visceral analgesia as established in the somatic pain field. Underlying mechanisms of stress-related visceral hypersensitivity may involve a combination of sensitization of primary afferents, central sensitization in response to input from the viscera and dysregulation of descending pathways that modulate spinal nociceptive transmission or analgesic response. Biochemical coding of stress involves the recruitment of corticotropin releasing factor (CRF) signaling pathways. Experimental studies established that activation of brain and peripheral CRF receptor subtype 1 plays a primary role in the development of stress-related delayed visceral hyperalgesia while subtype 2 activation induces analgesic response. In line with stress pathways playing a role in IBS, non-pharmacologic and pharmacologic treatment modalities aimed at reducing stress perception using a broad range of evidence-based mind-body interventions and centrally-targeted medications to reduce anxiety impact on brain patterns activated by visceral stimuli and dampen visceral pain. PMID:21575632

Effect of gate voltage polarity on the ionic liquid gating behavior of NdNiO3/NdGaO3 heterostructures

Directory of Open Access Journals (Sweden)

Yongqi Dong

2017-05-01

Full Text Available The effect of gate voltage polarity on the behavior of NdNiO3 epitaxial thin films during ionic liquid gating is studied using in situ synchrotron X-ray techniques. We show that while negative biases have no discernible effect on the structure or composition of the films, large positive gate voltages result in the injection of a large concentration of oxygen vacancies (∼3% and pronounced lattice expansion (0.17% in addition to a 1000-fold increase in sheet resistance at room temperature. Despite the creation of large defect densities, the heterostructures exhibit a largely reversible switching behavior when sufficient time is provided for the vacancies to migrate in and out of the thin film surface. The results confirm that electrostatic gating takes place at negative gate voltages for p-type complex oxides while positive voltages favor the electrochemical reduction of Ni3+. Switching between positive and negative gate voltages therefore involves a combination of electronic and ionic doping processes that may be utilized in future electrochemical transistors.

Electrochemical Single-Molecule Transistors with Optimized Gate Coupling

DEFF Research Database (Denmark)

Osorio, Henrry M.; Catarelli, Samantha; Cea, Pilar

2015-01-01

Electrochemical gating at the single molecule level of viologen molecular bridges in ionic liquids is examined. Contrary to previous data recorded in aqueous electrolytes, a clear and sharp peak in the single molecule conductance versus electrochemical potential data is obtained in ionic liquids....... These data are rationalized in terms of a two-step electrochemical model for charge transport across the redox bridge. In this model the gate coupling in the ionic liquid is found to be fully effective with a modeled gate coupling parameter, ξ, of unity. This compares to a much lower gate coupling parameter...

Heavy-ion-induced, gate-rupture in power MOSFETs

International Nuclear Information System (INIS)

Fischer, T.A.

1987-01-01

A new, heavy-ion-induced, burnout mechanism has been experimentally observed in power metal-oxide-semiconductor field-effect transistors (MOSFETs). This mechanism occurs when a heavy, charged particle passes through the gate oxide region of n- or p-channel devices having sufficient gate-to-source or gate-to-drain bias. The gate-rupture leads to significant permanent degradation of the device. A proposed failure mechanism is discussed and experimentally verified. In addition, the absolute immunity of p-channel devices to heavy-ion-induced, semiconductor burnout is demonstrated and discussed along with new, non-destructive, burnout testing methods

Feasibility and diagnostic accuracy of Ecg-gated SPECT myocardial perfusion imaging by a two-hour protocol: The Myofast study;Faisabilite et precision diagnostique d'un protocole de scintigraphie myocardique synchronisee a l'ECG en deux heures: l'etude Myofast

Energy Technology Data Exchange (ETDEWEB)

Dunet, V.; Costo, S.; Sabatier, R.; Grollier, G.; Bouvard, G.; Agostini, D. [CHU Cote-de-Nacre, Service de medecine nucleaire, 14 - Caen (France)

2010-04-15

Aim of the study: To assess the feasibility of early stress and rest myocardial perfusion and function study using a fast {sup 99m}Tc-tetrofosmin gated-SPECT protocol in patients with known coronary artery disease. Materials and methods: Forty-three patients (pts) (37 M, 6 F, mean age 63.8 +- 9.8 years) underwent a {sup 99m}Tc-Tetrofosmin gated-SPECT (Axis Picker-Philips) myocardial study and a coronary angiography (C.A.) within 3 months. Images were acquired (LEHR, eight bins, 40 sec per image) after injection of {sup 99m}Tc-tetrofosmin (200 to 380 MBq) early (15 min) post-stress (36 dipyridamole, two dobutamine and five ergo-metric stress), and at rest after {sup 99m}Tc-tetrofosmin reinjection (600 to 1150 MBq), in a total time not exceeding 2 hours. Processing was performed with Q.G.S. software using the 17-segment model. Pathological study was defined as a summed difference score (SDS) greater than or equal to 4 4, a fixed defect with summed rest score greater than or equal to 4 and/or L.V. dysfunction defined as myocardial stunning (variation between stress and rest L.V.E.F. greater than or equal to 4 5%), stress L.V.E.F. less than or equal to 45% or rest L.V.E.F. less than or equal to 40%. Results were compared with C.A., and stenosis greater than or equal to 4 50% was considered as significant. Results: For 100% the quality of SPECT imaging was good or excellent. For six patients gating was impossible because of arrhythmia. The overall sensitivity, specificity and accuracy were 95%, 50%, and 91%, respectively. The concordance between gated SPECT and C.A. was moderate (kappa = 0.45, S.E. = 0.15). Interestingly, early-gated acquisition permitted to underline left ventricular dysfunction in 11 cases (30%), of whom eight had poly vascular disease. Stunning was detected in six of 37 cases (16%), of whom six had poly vascular disease. Conclusion: A one-day two-hour {sup 99m}Tc-tetrofosmin gated-SPECT protocol to assess left ventricular perfusion and function is

Dual-gate polysilicon nanoribbon biosensors enable high sensitivity detection of proteins

International Nuclear Information System (INIS)

Zeimpekis, I; Sun, K; Hu, C; Ditshego, N M J; De Planque, M R R; Chong, H M H; Morgan, H; Ashburn, P; Thomas, O

2016-01-01

We demonstrate the advantages of dual-gate polysilicon nanoribbon biosensors with a comprehensive evaluation of different measurement schemes for pH and protein sensing. In particular, we compare the detection of voltage and current changes when top- and bottom-gate bias is applied. Measurements of pH show that a large voltage shift of 491 mV pH"−"1 is obtained in the subthreshold region when the top-gate is kept at a fixed potential and the bottom-gate is varied (voltage sweep). This is an improvement of 16 times over the 30 mV pH"−"1 measured using a top-gate sweep with the bottom-gate at a fixed potential. A similar large voltage shift of 175 mV is obtained when the protein avidin is sensed using a bottom-gate sweep. This is an improvement of 20 times compared with the 8.8 mV achieved from a top-gate sweep. Current measurements using bottom-gate sweeps do not deliver the same signal amplification as when using bottom-gate sweeps to measure voltage shifts. Thus, for detecting a small signal change on protein binding, it is advantageous to employ a double-gate transistor and to measure a voltage shift using a bottom-gate sweep. For top-gate sweeps, the use of a dual-gate transistor enables the current sensitivity to be enhanced by applying a negative bias to the bottom-gate to reduce the carrier concentration in the nanoribbon. For pH measurements, the current sensitivity increases from 65% to 149% and for avidin sensing it increases from 1.4% to 2.5%. (paper)

Tunnel field-effect transistor with two gated intrinsic regions

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Y. Zhang

2014-07-01

Full Text Available In this paper, we propose and validate (using simulations a novel design of silicon tunnel field-effect transistor (TFET, based on a reverse-biased p+-p-n-n+ structure. 2D device simulation results show that our devices have significant improvements of switching performance compared with more conventional devices based on p-i-n structure. With independent gate voltages applied to two gated intrinsic regions, band-to-band tunneling (BTBT could take place at the p-n junction, and no abrupt degenerate doping profile is required. We developed single-side-gate (SSG structure and double-side-gate (DSG structure. SSG devices with HfO2 gate dielectric have a point subthreshold swing of 9.58 mV/decade, while DSG devices with polysilicon gate electrode material and HfO2 gate dielectric have a point subthreshold swing of 16.39 mV/decade. These DSG devices have ON-current of 0.255 μA/μm, while that is lower for SSG devices. Having two nano-scale independent gates will be quite challenging to realize with good uniformity across the wafer and the improved behavior of our TFET makes it a promising steep-slope switch candidate for further investigations.

AlN and Al oxy-nitride gate dielectrics for reliable gate stacks on Ge and InGaAs channels

Energy Technology Data Exchange (ETDEWEB)

Guo, Y.; Li, H.; Robertson, J. [Engineering Department, Cambridge University, Cambridge CB2 1PZ (United Kingdom)

2016-05-28

AlN and Al oxy-nitride dielectric layers are proposed instead of Al{sub 2}O{sub 3} as a component of the gate dielectric stacks on higher mobility channels in metal oxide field effect transistors to improve their positive bias stress instability reliability. It is calculated that the gap states of nitrogen vacancies in AlN lie further away in energy from the semiconductor band gap than those of oxygen vacancies in Al{sub 2}O{sub 3}, and thus AlN might be less susceptible to charge trapping and have a better reliability performance. The unfavourable defect energy level distribution in amorphous Al{sub 2}O{sub 3} is attributed to its larger coordination disorder compared to the more symmetrically bonded AlN. Al oxy-nitride is also predicted to have less tendency for charge trapping.

Creativity and sensory gating indexed by the P50: selective versus leaky sensory gating in divergent thinkers and creative achievers.

Science.gov (United States)

Zabelina, Darya L; O'Leary, Daniel; Pornpattananangkul, Narun; Nusslock, Robin; Beeman, Mark

2015-03-01

Creativity has previously been linked with atypical attention, but it is not clear what aspects of attention, or what types of creativity are associated. Here we investigated specific neural markers of a very early form of attention, namely sensory gating, indexed by the P50 ERP, and how it relates to two measures of creativity: divergent thinking and real-world creative achievement. Data from 84 participants revealed that divergent thinking (assessed with the Torrance Test of Creative Thinking) was associated with selective sensory gating, whereas real-world creative achievement was associated with "leaky" sensory gating, both in zero-order correlations and when controlling for academic test scores in a regression. Thus both creativity measures related to sensory gating, but in opposite directions. Additionally, divergent thinking and real-world creative achievement did not interact in predicting P50 sensory gating, suggesting that these two creativity measures orthogonally relate to P50 sensory gating. Finally, the ERP effect was specific to the P50 - neither divergent thinking nor creative achievement were related to later components, such as the N100 and P200. Overall results suggest that leaky sensory gating may help people integrate ideas that are outside of focus of attention, leading to creativity in the real world; whereas divergent thinking, measured by divergent thinking tests which emphasize numerous responses within a limited time, may require selective sensory processing more than previously thought. Copyright © 2015 Elsevier Ltd. All rights reserved.

Double gated-integrator for shaping nuclear radiation detector signals

International Nuclear Information System (INIS)

Gal, J.

2001-01-01

A new shaper, the double gated-integrator, for shaping nuclear radiation detector signals is investigated both theoretically and experimentally. The double gated-integrator consists of a pre-filter and two cascaded gated integrators. Two kinds of pre-filters were considered: a rectangular one and an exponential one. The results of the theoretical calculation show that the best figure of demerit for the double gated-integrator with exponential pre-filter is 1.016. This means that its noise to signal ratio is only 1.6% worse than that it is for infinite cusp shaping. The practical realization of the exponential pre-filter and that of the double gated integrator, both in analogue and in digital way, is very simple. Therefore, the double gated-integrator with exponential pre-filter could be a promising solution for shaping nuclear radiation detector signals

Gate-keeper module for TANSY-KM5

International Nuclear Information System (INIS)

Rydz, R.; Norberg, L.; Urholm, L.; Grosshoeg, G.

1991-01-01

The purpose of the Gate-keeper is the control of the RDCs, the ADCs, and the constant fraction discriminator. The Gate-keeper synchronizes the units and ensures that the data taking is clean and not intermixed with other events. There are six Gate-Keepers in the system, one for each proton detector. All input circuits are designed to accept TTL as well as negative NIM signals. The output is 50 ohm TTL or negative NIM as defined by internal jumpers

Quality verification for respiratory gated proton therapy

International Nuclear Information System (INIS)

Kim, Eun Sook; Jang, Yo Jong; Park, Ji Yeon; Kang, Dong Yun; Yeom, Doo Seok

2013-01-01

To verify accuracy of respiratory gated proton therapy by measuring and analyzing proton beam delivered when respiratory gated proton therapy is being performed in our institute. The plan data of 3 patients who took respiratory gated proton therapy were used to deliver proton beam from proton therapy system. The manufactured moving phantom was used to apply respiratory gating system to reproduce proton beam which was partially irradiated. The key characteristics of proton beam, range, spreat-out Bragg peak (SOBP) and output factor were measured 5 times and the same categories were measured in the continuous proton beam which was not performed with respiratory gating system. Multi-layer ionization chamber was used to measure range and SOBP, and Scanditronix Wellhofer and farmer chamber was used to measure output factor. The average ranges of 3 patients (A, B, C), who had taken respiratory gated proton therapy or not, were (A) 7.226, 7.230, (B) 12.216, 12.220 and (C) 19.918, 19.920 g/cm 2 and average SOBP were (A) 4.950, 4.940, (B) 6.496, 6.512 and (C) 8.486, 8.490 g/cm 2 . And average output factor were (A) 0.985, 0.984 (B) 1.026, 1.027 and (C) 1.138, 1.136 cGy/MU. The differences of average range were -0.004, -0.004, -0.002 g/cm 2 , that of SOBP were 0.010, -0.016, -0.004 g/cm 2 and that of output factor were 0.001, -0.001, 0.002 cGy/MU. It is observed that the range, SOBP and output factor of proton beam delivered when respiratory gated proton therapy is being performed have the same beam quality with no significant difference compared to the proton beam which was continuously irradiated. Therefore, this study verified the quality of proton beam delivered when respiratory gated proton therapy and confirmed the accuracy of proton therapy using this

Alpha-Amylase Activity in Blood Increases after Pharmacological, But Not Psychological, Activation of the Adrenergic System.

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Urs M Nater

Full Text Available Alpha-amylase in both blood and saliva has been used as a diagnostic parameter. While studies examining alpha-amylase activity in saliva have shown that it is sensitive to physiological and psychological challenge of the adrenergic system, no challenge studies have attempted to elucidate the role of the adrenergic system in alpha-amylase activity in blood. We set out to examine the impact of psychological and pharmacological challenge on alpha-amylase in blood in two separate studies.In study 1, healthy subjects were examined in a placebo-controlled, double-blind paradigm using yohimbine, an alpha2-adrenergic antagonist. In study 2, subjects were examined in a standardized rest-controlled psychosocial stress protocol. Alpha-amylase activity in blood was repeatedly measured in both studies.Results of study 1 showed that alpha-amylase in blood is subject to stronger increases after injection of yohimbine compared to placebo. In study 2, results showed that there was no significant effect of psychological stress compared to rest.Alpha-amylase in blood increases after pharmacological activation of the adrenergic pathways suggesting that sympathetic receptors are responsible for these changes. Psychological stress, however, does not seem to have an impact on alpha-amylase in blood. Our findings provide insight into the mechanisms underlying activity changes in alpha-amylase in blood in healthy individuals.

Pills or push-ups? Effectiveness and public perception of pharmacological and non-pharmacological cognitive enhancement

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Lucius eCaviola

2015-12-01

Full Text Available We review work on the effectiveness of different forms of cognitive enhancement, both pharmacological and non-pharmacological. We consider caffeine, methylphenidate, and modafinil for pharmacological cognitive enhancement (PCE and computer training, physical exercise, and sleep for non-pharmacological cognitive enhancement (NPCE. We find that all of the techniques described can produce significant beneficial effects on cognitive performance. However, effect sizes are moderate, and consistently dependent on individual and situational factors as well as the cognitive domain in question. Although meta-analyses allowing a quantitative comparison of effectiveness across techniques are lacking to date, we can conclude that PCE is not more effective than NPCE. We discuss the physiological reasons for this limited effectiveness.We then propose that even though their actual effectiveness seems similar, in the general public PCE is perceived as fundamentally different from NPCE, in terms of effectiveness, but also in terms of acceptability. We illustrate the potential consequences such a misperception of PCE can have.

Stress Characterization of 4H-SiC Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) using Raman Spectroscopy and the Finite Element Method.

Science.gov (United States)

Yoshikawa, Masanobu; Kosaka, Kenichi; Seki, Hirohumi; Kimoto, Tsunenobu

2016-07-01

We measured the depolarized and polarized Raman spectra of a 4H-SiC metal-oxide-semiconductor field-effect transistor (MOSFET) and found that compressive stress of approximately 20 MPa occurs under the source and gate electrodes and tensile stress of approximately 10 MPa occurs between the source and gate electrodes. The experimental result was in close agreement with the result obtained by calculation using the finite element method (FEM). A combination of Raman spectroscopy and FEM provides much data on the stresses in 4H-SiC MOSFET. © The Author(s) 2016.

Active gated imaging in driver assistance system

Science.gov (United States)

Grauer, Yoav

2014-04-01

In this paper, we shall present the active gated imaging system (AGIS) in relation to the automotive field. AGIS is based on a fast-gated camera and pulsed illuminator, synchronized in the time domain to record images of a certain range of interest. A dedicated gated CMOS imager sensor and near infra-red (NIR) pulsed laser illuminator, is presented in this paper to provide active gated technology. In recent years, we have developed these key components and learned the system parameters, which are most beneficial to nighttime (in all weather conditions) driving in terms of field of view, illumination profile, resolution, and processing power. We shall present our approach of a camera-based advanced driver assistance systems (ADAS) named BrightEye™, which makes use of the AGIS technology in the automotive field.

Role of myocardial perfusion single photon emission computed tomography in pediatric cardiology practice

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Sundaram P

2009-01-01

Full Text Available Diagnostic and prognostic power of myocardial perfusion imaging in patients with coronary artery disease has been demonstrated with planar imaging which was further improvised with addition of gated SPECT and newer Technetium labeled myocardial perfusion tracers like SestaMIBI, Tetrofosmin. Myocardial perfusion abnormalities at rest and after stress are considered to be the best predictors of cardiac event-free survival in adults with ischemic heart disease. This article highlights various myocardial perfusion imaging (MPIradiopharmaceuticals, exercise procedures, pharmacological stress protocols, indications for MPI and myocardial perfusion patterns in children with some of the common congenital and acquired heart diseases.

Aroma Effects on Physiologic and Cognitive Function Following Acute Stress: A Mechanism Investigation.

Science.gov (United States)

Chamine, Irina; Oken, Barry S

2016-09-01

Aromas may improve physiologic and cognitive function after stress, but associated mechanisms remain unknown. This study evaluated the effects of lavender aroma, which is commonly used for stress reduction, on physiologic and cognitive functions. The contribution of pharmacologic, hedonic, and expectancy-related mechanisms of the aromatherapy effects was evaluated. Ninety-two healthy adults (mean age, 58.0 years; 79.3% women) were randomly assigned to three aroma groups (lavender, perceptible placebo [coconut], and nonperceptible placebo [water] and to two prime subgroups (primed, with a suggestion of inhaling a powerful stress-reducing aroma, or no prime). Participants' performance on a battery of cognitive tests, physiologic responses, and subjective stress were evaluated at baseline and after exposure to a stress battery during which aromatherapy was present. Participants also rated the intensity and pleasantness of their assigned aroma. Pharmacologic effects of lavender but not placebo aromas significantly benefited post-stress performance on the working memory task (F(2, 86) = 5.41; p = 0.006). Increased expectancy due to positive prime, regardless of aroma type, facilitated post-stress performance on the processing speed task (F(1, 87) = 8.31; p = 0.005). Aroma hedonics (pleasantness and intensity) played a role in the beneficial lavender effect on working memory and physiologic function. The observable aroma effects were produced by a combination of mechanisms involving aroma-specific pharmacologic properties, aroma hedonic properties, and participant expectations. In the future, each of these mechanisms could be manipulated to produce optimal functioning.

The cooperative voltage sensor motion that gates a potassium channel.

Science.gov (United States)

Pathak, Medha; Kurtz, Lisa; Tombola, Francesco; Isacoff, Ehud

2005-01-01

The four arginine-rich S4 helices of a voltage-gated channel move outward through the membrane in response to depolarization, opening and closing gates to generate a transient ionic current. Coupling of voltage sensing to gating was originally thought to operate with the S4s moving independently from an inward/resting to an outward/activated conformation, so that when all four S4s are activated, the gates are driven to open or closed. However, S4 has also been found to influence the cooperative opening step (Smith-Maxwell et al., 1998a), suggesting a more complex mechanism of coupling. Using fluorescence to monitor structural rearrangements in a Shaker channel mutant, the ILT channel (Ledwell and Aldrich, 1999), that energetically isolates the steps of activation from the cooperative opening step, we find that opening is accompanied by a previously unknown and cooperative movement of S4. This gating motion of S4 appears to be coupled to the internal S6 gate and to two forms of slow inactivation. Our results suggest that S4 plays a direct role in gating. While large transmembrane rearrangements of S4 may be required to unlock the gating machinery, as proposed before, it appears to be the gating motion of S4 that drives the gates to open and close.

Role of voltage-gated L-type Ca2+ channel isoforms for brain function.

Science.gov (United States)

Striessnig, J; Koschak, A; Sinnegger-Brauns, M J; Hetzenauer, A; Nguyen, N K; Busquet, P; Pelster, G; Singewald, N

2006-11-01

Voltage-gated LTCCs (L-type Ca2+ channels) are established drug targets for the treatment of cardiovascular diseases. LTCCs are also expressed outside the cardiovascular system. In the brain, LTCCs control synaptic plasticity in neurons, and DHP (dihydropyridine) LTCC blockers such as nifedipine modulate brain function (such as fear memory extinction and depression-like behaviour). Voltage-sensitive Ca2+ channels Cav1 .2 and Cav1.3 are the predominant brain LTCCs. As DHPs and other classes of organic LTCC blockers inhibit both isoforms, their pharmacological distinction is impossible and their individual contributions to defined brain functions remain largely unknown. Here, we summarize our recent experiments with two genetically modified mouse strains, which we generated to explore the individual biophysical features of Cav1.2 and Cav1.3 LTCCs and to determine their relative contributions to various physiological peripheral and neuronal functions. The results described here also allow predictions about the pharmacotherapeutic potential of isoform-selective LTCC modulators.

Dose verification for respiratory-gated volumetric modulated arc therapy

Energy Technology Data Exchange (ETDEWEB)

Qian Jianguo; Xing Lei; Liu Wu; Luxton, Gary, E-mail: gluxton@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305 (United States)

2011-08-07

A novel commercial medical linac system (TrueBeam(TM), Varian Medical Systems, Palo Alto, CA) allows respiratory-gated volumetric modulated arc therapy (VMAT), a new modality for treating moving tumors with high precision and improved accuracy by allowing for regular motion associated with a patient's breathing during VMAT delivery. The purpose of this work is to adapt a previously-developed dose reconstruction technique to evaluate the fidelity of VMAT treatment during gated delivery under clinic-relevant periodic motion related to patient breathing. A Varian TrueBeam system was used in this study. VMAT plans were created for three patients with lung or pancreas tumors. Conventional 6 and 15 MV beams with flattening filter and high-dose-rate 10 MV beams with no flattening filter were used in these plans. Each patient plan was delivered to a phantom first without gating and then with gating for three simulated respiratory periods (3, 4.5 and 6 s). Using the adapted log-file-based dose reconstruction procedure supplemented with ion chamber array (Seven29(TM), PTW, Freiburg, Germany) measurements, the delivered dose was used to evaluate the fidelity of gated VMAT delivery. Comparison of Seven29 measurements with and without gating showed good agreement with gamma-index passing rates above 99% for 1%/1 mm dose accuracy/distance-to-agreement criteria. With original plans as reference, gamma-index passing rates were 100% for the reconstituted plans (1%/1 mm criteria) and 93.5-100% for gated Seven29 measurements (3%/3 mm criteria). In the presence of leaf error deliberately introduced into the gated delivery of a pancreas patient plan, both dose reconstruction and Seven29 measurement consistently indicated substantial dosimetric differences from the original plan. In summary, a dose reconstruction procedure was demonstrated for evaluating the accuracy of respiratory-gated VMAT delivery. This technique showed that under clinical operation, the TrueBeam system

The comparison of gamma-radiation and electrical stress influences on oxide and interface defects in power VDMOSFET

Directory of Open Access Journals (Sweden)

Đorić-Veljković Snežana M.

2013-01-01

Full Text Available The behaviour of oxide and interface defects in n-channel power vertical double-diffused metal-oxide-semiconductor field-effect transistors, firstly degraded by the gamma-irradiation and electric field and subsequently recovered and annealed, is presented. By analyzing the transfer characteristic shifts, the changes of threshold voltage and underlying changes of gate oxide and interface trap densities during the stress (recovery, annealing of investigated devices, it is shown that these two types of stress influence differently on the gate oxide and the SiO2-Si interface. [Projekat Ministarstva nauke Republike Srbije, br. OI171026

Integration of biomolecular logic gates with field-effect transducers

Energy Technology Data Exchange (ETDEWEB)

Poghossian, A., E-mail: a.poghossian@fz-juelich.de [Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, Campus Juelich, Heinrich-Mussmann-Str. 1, D-52428 Juelich (Germany); Institute of Bio- and Nanosystems, Research Centre Juelich GmbH, D-52425 Juelich (Germany); Malzahn, K. [Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, Campus Juelich, Heinrich-Mussmann-Str. 1, D-52428 Juelich (Germany); Abouzar, M.H. [Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, Campus Juelich, Heinrich-Mussmann-Str. 1, D-52428 Juelich (Germany); Institute of Bio- and Nanosystems, Research Centre Juelich GmbH, D-52425 Juelich (Germany); Mehndiratta, P. [Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, Campus Juelich, Heinrich-Mussmann-Str. 1, D-52428 Juelich (Germany); Katz, E. [Department of Chemistry and Biomolecular Science, NanoBio Laboratory (NABLAB), Clarkson University, Potsdam, NY 13699-5810 (United States); Schoening, M.J. [Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, Campus Juelich, Heinrich-Mussmann-Str. 1, D-52428 Juelich (Germany); Institute of Bio- and Nanosystems, Research Centre Juelich GmbH, D-52425 Juelich (Germany)

2011-11-01

Highlights: > Enzyme-based AND/OR logic gates are integrated with a capacitive field-effect sensor. > The AND/OR logic gates compose of multi-enzyme system immobilised on sensor surface. > Logic gates were activated by different combinations of chemical inputs (analytes). > The logic output (pH change) produced by the enzymes was read out by the sensor. - Abstract: The integration of biomolecular logic gates with field-effect devices - the basic element of conventional electronic logic gates and computing - is one of the most attractive and promising approaches for the transformation of biomolecular logic principles into macroscopically useable electrical output signals. In this work, capacitive field-effect EIS (electrolyte-insulator-semiconductor) sensors based on a p-Si-SiO{sub 2}-Ta{sub 2}O{sub 5} structure modified with a multi-enzyme membrane have been used for electronic transduction of biochemical signals processed by enzyme-based OR and AND logic gates. The realised OR logic gate composes of two enzymes (glucose oxidase and esterase) and was activated by ethyl butyrate or/and glucose. The AND logic gate composes of three enzymes (invertase, mutarotase and glucose oxidase) and was activated by two chemical input signals: sucrose and dissolved oxygen. The developed integrated enzyme logic gates produce local pH changes at the EIS sensor surface as a result of biochemical reactions activated by different combinations of chemical input signals, while the pH value of the bulk solution remains unchanged. The pH-induced charge changes at the gate-insulator (Ta{sub 2}O{sub 5}) surface of the EIS transducer result in an electronic signal corresponding to the logic output produced by the immobilised enzymes. The logic output signals have been read out by means of a constant-capacitance method.

Integration of biomolecular logic gates with field-effect transducers

International Nuclear Information System (INIS)

Poghossian, A.; Malzahn, K.; Abouzar, M.H.; Mehndiratta, P.; Katz, E.; Schoening, M.J.

2011-01-01

Highlights: → Enzyme-based AND/OR logic gates are integrated with a capacitive field-effect sensor. → The AND/OR logic gates compose of multi-enzyme system immobilised on sensor surface. → Logic gates were activated by different combinations of chemical inputs (analytes). → The logic output (pH change) produced by the enzymes was read out by the sensor. - Abstract: The integration of biomolecular logic gates with field-effect devices - the basic element of conventional electronic logic gates and computing - is one of the most attractive and promising approaches for the transformation of biomolecular logic principles into macroscopically useable electrical output signals. In this work, capacitive field-effect EIS (electrolyte-insulator-semiconductor) sensors based on a p-Si-SiO 2 -Ta 2 O 5 structure modified with a multi-enzyme membrane have been used for electronic transduction of biochemical signals processed by enzyme-based OR and AND logic gates. The realised OR logic gate composes of two enzymes (glucose oxidase and esterase) and was activated by ethyl butyrate or/and glucose. The AND logic gate composes of three enzymes (invertase, mutarotase and glucose oxidase) and was activated by two chemical input signals: sucrose and dissolved oxygen. The developed integrated enzyme logic gates produce local pH changes at the EIS sensor surface as a result of biochemical reactions activated by different combinations of chemical input signals, while the pH value of the bulk solution remains unchanged. The pH-induced charge changes at the gate-insulator (Ta 2 O 5 ) surface of the EIS transducer result in an electronic signal corresponding to the logic output produced by the immobilised enzymes. The logic output signals have been read out by means of a constant-capacitance method.

Gates to the CERN site - Changes and reminder

CERN Multimedia

2006-01-01

I. Gate E New international agreements have been concluded between CERN, Switzerland and France concerning Gate E ('Charles de Gaulle Gate') aimed at reducing congestion at the Prévessin-RN84 and Meyrin Route customs posts, in particular during the work associated with the future Cornavin-Meyrin-CERN tram link. On the basis of these agreements, the Director-General has issued a revised version of the Rules for the use of Gate E (document CERN/DSU-RH/12222/Rev.1 which is available on the Relations with Host States website at: http:/www.cern.ch/relations/), which will enter into force as of 1 December 2006, and includes the following provisions: Gate E is open from Monday to Friday, except on official CERN holidays, from 7.00 a.m. to 9.00 a.m. for access to the site, and from 5.00 p.m. to 7.00 p.m. for departure from the site (instead of 7.30 a.m. to 9.00 a.m. and 5.00 p.m. to 6.30 p.m. respectively). The following persons are authorised to use Gate E: members of the CERN personnel (who may be accompanie...

Gates to the CERN site - Changes and reminder

CERN Multimedia

2006-01-01

I. Gate E New international agreements have been concluded between CERN, Switzerland and France concerning Gate E ('Charles de Gaulle Gate') aimed at reducing congestion at the Prévessin-RN84 and Meyrin Route customs posts, in particular during the work associated with the future Cornavin-Meyrin-CERN tram link. On the basis of these agreements, the Director-General has issued a revised version of the Rules for the use of Gate E (document CERN/DSU-RH/12222/Rev.1 which is available on the Relations with Host States website at: http:/www.cern.ch/relations/), which will enter into force as of 1December 2006, and includes the following provisions: Gate E is open from Monday to Friday, except on official CERN holidays, from 7.00 a.m. to 9.00 a.m. for access to the site, and from 5.00 p.m. to 7.00 p.m. for departure from the site (instead of 7.30 a.m. to 9.00 a.m. and 5.00 p.m. to 6.30 p.m. respectively). The following persons are authorised to use Gate E: members of the CERN personnel (who may be accompani...