Each superconductor logic family has distinct features and advantages. For instance, adiabatic quantum-flux-parametron (AQFP) circuits operate with very high energy efficiency, and rapid ...single-flux-quantum (RSFQ) circuits operate at very high clock frequencies. To build a hybrid system that combines the above advantages, we propose a compact interface between AQFP and RSFQ circuits that converts current signals in AQFP logic into flux signals in RSFQ logic using a non-adiabatic quantum-flux-parametron gate. Compared to a previously proposed AQFP/RSFQ interface, the proposed interface has far fewer Josephson junctions (4 vs. 11). We optimize the circuit parameters of the AQFP/RSFQ interface and demonstrate the interface at low speed as proof of concept. Furthermore, we demonstrate data propagation between AQFP circuits along a long passive transmission line via the AQFP/RSFQ interface at low speed to show that the AQFP/RSFQ interface can alleviate the interconnect length limit in AQFP circuits.
We report on influence of neutron radiation on majority and minority carrier traps in n-type 4H-SiC. Together with the increase of the well-known carbon vacancy (VC) majority carrier related trap, ...neutron irradiation has introduced two deep traps, labeled as EH1 and EH3 with the activation energies for electron emission estimated as 0.4 and 0.7 eV bellow the conduction band, respectively. Based on Laplace deep level transient spectroscopy (DLTS) results, we have assigned EH1 trap to silicon vacancy (VSi). Two minority carrier traps labelled as B and D-center were detected by minority transient spectroscopy (MCTS) and assigned to substitutional boron BSi and BC, respectively. Activation energies for hole emission for B and D-center are estimated as 0.27 and 0.60 eV above the valence band, respectively. We have identified two emission lines for D-center by Laplace-MCTS measurements and assigned them to BC sitting at hexagonal (−h) and cubic (−k) lattice sites.
Abstract
Correlative microscopy and block-face imaging (CoMBI), a method that we previously developed, is characterized by the ability to correlate between serial block-face images as 3-dimensional ...(3D) datasets and sections as 2-dimensional (2D) microscopic images. CoMBI has been performed for the morphological analyses of various biological specimens, and its use is expanding. However, the conventional CoMBI system utilizes a cryostat, which limits its compatibility to only frozen blocks and the resolution of the block-face image. We developed a new CoMBI system that can be applied to not only frozen blocks but also paraffin blocks, and it has an improved magnification for block-face imaging. The new system, called CoMBI-S, comprises sliding-type sectioning devices and imaging devices, and it conducts block slicing and block-face imaging automatically. Sections can also be collected and processed for microscopy as required. We also developed sample preparation methods for improving the qualities of the block-face images and 3D rendered volumes. We successfully obtained correlative 3D datasets and 2D microscopic images of zebrafish, mice, and fruit flies, which were paraffin-embedded or frozen. In addition, the 3D datasets at the highest magnification could depict a single neuron and bile canaliculus.
Silicon carbide diodes for neutron detection Coutinho, José; Torres, Vitor J.B.; Capan, Ivana ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2021, Letnik:
986
Journal Article
Recenzirano
In the last two decades we have assisted to a rush towards finding a 3He-replacing technology capable of detecting neutrons emitted from fissile isotopes. The demand stems from applications like ...nuclear war-head screening or preventing illicit traffic of radiological materials. Semiconductor detectors stand among the strongest contenders, particularly those based on materials possessing a wide band gap like silicon carbide (SiC). We review the workings of SiC-based neutron detectors, along with several issues related to material properties, device fabrication and testing. The paper summarizes the experimental and theoretical work carried out within the E-SiCure project (Engineering Silicon Carbide for Border and Port Security), co-funded by the NATO Science for Peace and Security Programme. The main goal was the development of technologies to support the fabrication of radiation-hard silicon carbide detectors of special nuclear materials. Among the achievements, we have the development of successful Schottky barrier based detectors and the identification of the main carrier life-time-limiting defects in the SiC active areas, either already present in pristine devices or introduced upon exposure to radiation fields. The physical processes involved in neutron detection are described. Material properties as well as issues related to epitaxial growth and device fabrication are addressed. The presence of defects in as-grown material, as well as those introduced by ionizing radiation are reported. We finally describe several experiments carried out at the Jozef Stefan Institute TRIGA Mark II reactor (Ljubljana, Slovenia), where a set of SiC-based neutron detectors were tested, some of which being equipped with a thermal neutron converter layer. We show that despite the existence of large room for improvement, Schottky barrier diodes based on state-of-the-art 4H-SiC are closing the gap between gas- and semiconductor-based detectors regarding their sensitivity.
In order to break through limits of conventional MRAMs, MTJs with strain-induced magnetic anisotropy were intensively tested as SOT-MRAM cells. Small critical switching-current of 10–25 μA and ...switching-voltage of about 0.055 V, and almost no retention energy dependence of them were predicted and confirmed by experiments. Finally, high write efficiency of 1750 kBT/V (4.1 kBT/μA) and high write-power efficiency of 100 kBT/(μA·V) were obtained.
We report on boron-related defects in the low-doped n-type (nitrogen-doped) 4H-SiC semitransparent Schottky barrier diodes (SBDs) studied by minority carrier transient spectroscopy (MCTS). An unknown ...concentration of boron was introduced during chemical vapor deposition (CVD) crystal growth. Boron incorporation was found to lead to the appearance of at least two boron-related deep-level defects, namely, shallow (B) and deep boron (D-center), with concentrations as high as 1 × 10
cm
. Even though the boron concentration exceeded the nitrogen doping concentration by almost an order of magnitude, the steady-state electrical characteristics of the n-type 4H-SiC SBDs did not deteriorate.
A 70-year-old man with multicentric Castleman disease (MCD) was admitted to our hospital with jaundice and ascites. Elevations in his bilirubin and interleukin-6 levels were noted, and computed ...tomography revealed hepatic atrophy and portal vein and bile duct disorders. Steroid therapy was started for MCD, but he died of hepatic failure. An autopsy revealed that the MCD activity was mild, but advanced fibrosis and cholestasis were observed in the liver. Mild infiltration of interleukin-6-positive plasma cells was noted in the highly fibrotic area of the liver. Although rare, liver and biliary tract damage may be also considered organ disorders of MCD.
A 66-year-old man, who had undergone plasma exchange 30 years previously in Egypt for the treatment of falciparum malaria, was referred to our hospital for treatment of chronic hepatitis C (HCV). An ...analysis of the 655-nucleotide 5′-untranslated region-core region sequence revealed infection with HCV subtype 1g. A phylogenetic analysis of the full-length HCV genome confirmed that the patient's HCV was subtype 1g, which was the first case identified in Japan. Although his HCV possessed several naturally occurring resistance-associated substitutions in the nonstructural (NS) 3 and NS5A regions, he was successfully treated by combination therapy with glecaprevir/pibrentasvir.
Background
Patients with morbid obesity selected for bariatric surgery have a high prevalence of nonalcoholic steatohepatitis (NASH); however, the incidence is varied and depends on race. The ...prevalence of NASH in obese Japanese patients is unknown. We evaluated the prevalence of NASH in a prospective cohort of Japanese patients with morbid obesity.
Methods
From October 2009 to July 2011, consecutive patients requiring bariatric surgery underwent a liver biopsy during the operation. The indications for bariatric surgery followed the guidelines of the Asia–Pacific Metabolic and Bariatric Surgery Society.
Results
One hundred two patients (55 males and 47 females, age 42.7 ± 10.7 years) were analyzed. The mean body mass index was 42.1 ± 8.2 kg/m
2
. Among the 102 patients, 84 patients (82.4 %) had nonalcoholic fatty liver disease and 79 patients (77.5 %) had NASH. The grading and staging of NASH by Brunt’s classification were as follows: grade 0 steatosis, one patient; grade 1 steatosis, 35 patients; grade 2 steatosis, 32 patients; grade 3 steatosis, 11 patients; stage 1 fibrosis, 25 patients; stage 2 fibrosis, 38 patients; stage 3 fibrosis, 16 patients, stage 4 fibrosis, no patients. The body weight, waist–hip ratio, visceral fat area, and aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transpeptidase, fasting plasma glucose, fasting plasma insulin, C peptide, hemoglobin A
1c
, and homeostasis model assessment insulin resistance levels were significantly elevated in the NASH group in comparison with the non-NASH group. The platelet count was significantly decreased in the NASH group. The waist–hip ratio and the alanine aminotransferase, fasting plasma glucose, and homeostasis model assessment insulin resistance levels were found to be independent predictors of NASH in a multivariate analysis.
Conclusion
The prevalence of NASH was 77.5 % in this prospective Japanese cohort. The prevalence of NASH in Japanese morbidly obese patients was extremely high, and early intervention should be undertaken.
Background
Patients with morbid obesity are complicated with metabolic diseases and have a high incidence of non-alcoholic fatty liver disease (NAFLD), including non-alcoholic steatohepatitis (NASH).
...Methods
We report on a follow-up study of a cohort included 102 obese patients (55 males and 47 females, mean age 42.9 ± 10.6 years) undergoing bariatric surgery for the management of morbid obesity. Abdominal computed tomography was performed before and 1 year after surgery. Anthropometric and biochemical measurements were performed at 1, 3, and 5 years after surgery.
Results
The mean body mass index (BMI) of the NAFLD patients improved from 42.5 ± 8.3 kg/m
2
to 28.5 ± 6.9, and 29.1 ± 5.7, 29.7 ± 5.5 kg/m
2
at 1, 3, and 5 years, respectively. The liver fat accumulation and visceral fat areas were significantly improved at 1 year after surgery. The decrease in the BMI, waist-hip ratio, body fat percentage, and basal metabolic rate remained decreased for at least 5 years after surgery. Blood test findings including AST, ALT, γ-GTP, uric acid, albumin, CRP, HDL cholesterol, LDL cholesterol, triglycerides, and homeostasis model assessment insulin resistance (HOMA-IR) were also still improved at least 5 years after surgery.
Conclusion
Bariatric surgery is useful for ensuring the long-term treatment of NAFLD/NASH in morbidly obese Japanese patients. Bariatric surgery is a therapeutic option for patients resistant to conventional treatment.
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