13 research outputs found
Ge/SiGe Quantum Well p-i-n Structures for Uncooled Infrared Bolometers
Cataloged from PDF version of article.The temperature dependence of current is
investigated experimentally for silicon–germanium (Si-Ge)
multi-quantum-well p-i-n devices on Si substrates as uncooled
bolometer active layers. Temperature coefficient of resistance
values as high as −5.8%/K are recorded. This value is
considerably higher than that of even commercial bolometer
materials in addition to being well above the previous efforts
based on CMOS compatible materials
Ge/SiGe quantum well P-I-N structures for uncooled infrared bolometers
The temperature dependence of current is investigated experimentally for silicon-germanium (Si-Ge) multi-quantum-well p-i-n devices on Si substrates as uncooled bolometer active layers. Temperature coefficient of resistance values as high as-5.8%/K are recorded. This value is considerably higher than that of even commercial bolometer materials in addition to being well above the previous efforts based on CMOS compatible materials. © 2006 IEEE
Using nanogap in label-free impedance based electrical biosensors to overcome electrical double layer effect
Point-of-care biosensor applications require low-cost and low-power solutions. They offer being easily accessible at home site. They are usable without any complex sample handling or any kind of special expertise. Impedance spectroscopy has been utilized for point-of-care biosensor applications; however, electrical double layer formed due to ions in the solution of interest has been a challenge, due to shielding of the electric field used for sensing the target molecules. Here in this study, we demonstrate a nanogap based biosensor structure with a relatively low frequency (1–100 kHz) measurement technique, which not only eliminates the undesired shielding effect of electrical double layer but also helps in minimizing the measurement volume and enabling low concentration (µ molar level) detection of target molecules (streptavidin). Repeatability and sensitivity tests proved stable and reliable operation of the sensors. These biosensors might offer attributes such as low-cost label-free detection, fast measurement and monolithic chip integrability. © 2015, Springer-Verlag Berlin Heidelberg
Chronic Granulomatous Disease Presenting With Hypogammaglobulinemia
Chronic granulomatous disease (CGD) is a primary immunodeficiency disorder caused by inherited defects in the nicotinamide adenine dinucleotide phosphate oxidase complex. The neutrophils of patients with CGD can ingest bacteria normally, but the oxidative processes that lead to superoxide anion formation, hydrogen peroxide production, nonoxidative pathway activation, and bacterial killing are impaired. Serious infections result from microorganisms that produce catalase. Immunoglobulin levels of patients with CGD are usually normal or elevated. We describe a patient with CGD associated with hypogammaglobulinemia, an unusual co-occurrence
Topiramate: A novel therapeutic candidate for diabetes and aggression? positron emission tomography (PET) findings
Background: There is still limited knowledge regarding the role of impaired brain glucose metabolism in the generation of aggression during diabetes. Additionally, there are rapidly replicating piece of evidence suggesting that topiramate may exert significant mood stabilizing effect. In this respect, we aimed to evaluate the neurometabolic correlates of the therapeutic effect of topiramate in a patient with diabetes and Intermittent explosive disorder (IED). Methods: We measured regional cerebral glucose metabolism using 2-[18F]-fluoro-2-deoxy-D-glucose and positron emission tomography (FDG-PET) in a diabetic patient with aggressive outbursts before and after treatment with topiramate. In order to reveal a defined information underlying the improvement of the aggressive symptoms we also combined the PET with Modified Overt Aggression Scale. Results: We have found that topiramate leads to the improvement in Modified Overt Aggression Scale that was well correlated with the increase in cortical brain metabolism. Discussion: The therapeutic role of topiramate may not only suggest secondary deficits due to diminished functions of the cortical part of emotional circuits but also indicate that diabetic individuals may be vulnerable to lower cerebral glucose metabolism in cortical regions. Further clinical trials that include well-conducted randomized controlled trials and cohort studies by using other methods (i.e., magnetic resonance spectroscopy and quantitative EEG analysis) are necessary to confirm our preliminary findings. © 2016 Bentham Science Publishers
Using nanogap in label-free impedance based electrical biosensors to overcome electrical double layer effect
Guler, Mustafa/0000-0003-1168-202X; Acar, Handan/0000-0001-8708-9279WOS: 000397499300008Point-of-care biosensor applications require low-cost and low-power solutions. They offer being easily accessible at home site. They are usable without any complex sample handling or any kind of special expertise. Impedance spectroscopy has been utilized for point-of-care biosensor applications; however, electrical double layer formed due to ions in the solution of interest has been a challenge, due to shielding of the electric field used for sensing the target molecules. Here in this study, we demonstrate a nanogap based biosensor structure with a relatively low frequency (1-100 kHz) measurement technique, which not only eliminates the undesired shielding effect of electrical double layer but also helps in minimizing the measurement volume and enabling low concentration (A mu molar level) detection of target molecules (streptavidin). Repeatability and sensitivity tests proved stable and reliable operation of the sensors. These biosensors might offer attributes such as low-cost label-free detection, fast measurement and monolithic chip integrability.European Union Framework Program 7 Marie Curie IRG [239444, 249196]; COST NanoTPEuropean Cooperation in Science and Technology (COST); TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [109E044, 112M004, 112E052, 112M944, 113M815]; TUBITAK-BIDEBTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)This work was supported in part by European Union Framework Program 7 Marie Curie IRG Grant 239444 and 249196, COST NanoTP, TUBITAK Grants 109E044, 112M004, 112E052, 112M944 and 113M815. The authors acknowledge support from TUBITAK-BIDEB. The authors thank Firat Yilmaz for his contributions and Dr. Mohammad Ghaffari for SEM images
Association between APOE polymorphisms and mesial temporal lobe epilepsy with hippocampal sclerosis
To evaluate the hypothetical link between apolipoprotein E (APOE) polymorphisms and mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) and whether presence of APOE epsilon4 allele shortens the latent period between febrile seizures and epilepsy. A further interest is whether presence of APOE epsilon4 allele has an impact on severity of the disease. Forty-seven patients with MTLE-HS were compared with 62 controls. APOE polymorphisms were determined from lymphocytes by standard methods. Eight patients (17%) and 10 controls (16.1%) were demonstrated to have one APOE epsilon4 allele. There was not any statistically significant difference in APOE epsilon4 frequency between patients and controls (P > 0.05). There was not any difference statistically according to onset age of epilepsy and the presence of APOE epsilon4 allele within patient group. APOE epsilon4 polymorphisms did not influence the severity of epilepsy. APOE epsilon4 polymorphisms had no impact on outcome after surgery. Patients with bilateral memory deficits, bilateral hippocampal atrophy and with bilateral epileptiform interictal EEG transients, were independently compared with patients having unilateral features and there were not any statistically significant differences. This study has found no association between APOE epsilon4 polymorphisms and presentation of MTLE-HS in a group of Turkish patients
Modeling and Simulation of Void Closure during Steckel Mill Rolling for Steel Plate
Internal void defects as shrinkage porosity, gas bubble, and thermo-mechanical cracks are usually formed during steel casting processes. These defects have critical impact on the quality and service life of hot-rolled products. Study of the possibility of self-healing of existing internal defects during hot-rolling process has been of interest to industry and researchers. Prediction of void closure is extremely useful in relation to better product design and manufacturing process optimization. Herein, a 3D finite element model of the slab hot-rolling process is developed to simulate and analyze the healing of internal voids in hot-rolled steel plate. The material model for the steel plate is developed based on Johnson–Cook constitutive relation to accurately represent its viscoplastic behavior at high temperatures as well as account for strain rate sensitivity. The study evaluates the thermal and mechanical response of low-carbon steel slabs having pre-existing voids during multi-pass strands reverse hot-rolling process. Through thickness plastic strains within the slab are found to influence void closure. Results show that variation in void size and locations also affect the healing possibilities. Finally, the effect of thermal history and thermo-mechanical stresses on void closure is studied