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1.
Phys Rev E ; 105(2-2): 025203, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35291161

ABSTRACT

We present an experimental method to generate quasiperpendicular supercritical magnetized collisionless shocks. In our experiment, ambient nitrogen (N) plasma is at rest and well magnetized, and it has uniform mass density. The plasma is pushed by laser-driven ablation aluminum (Al) plasma. Streaked optical pyrometry and spatially resolved laser collective Thomson scattering clarify structures of plasma density and temperatures, which are compared with one-dimensional particle-in-cell simulations. It is indicated that just after the laser irradiation, the Al plasma is magnetized by a self-generated Biermann battery field, and the plasma slaps the incident N plasma. The compressed external field in the N plasma reflects N ions, leading to counterstreaming magnetized N flows. Namely, we identify the edge of the reflected N ions. Such interacting plasmas form a magnetized collisionless shock.

2.
Phys Rev Lett ; 123(23): 235101, 2019 Dec 06.
Article in English | MEDLINE | ID: mdl-31868466

ABSTRACT

A 3D fully kinetic simulation shows that the lower-hybrid drift instability disturbs the front of magnetic reconnection outflow jets and additionally causes energy dissipation. The result is very consistent with a disturbance observed at the dipolarization front (DF) in Earth's magnetotail by the Magnetospheric Multiscale (MMS) mission. A fully kinetic dispersion relation solver, validated by the MMS observations, further predicts that the disturbance of the reconnection jet front could occur over different parameter regimes in space plasmas including Earth's DF and solar flares.

4.
Acta Neuropathol Commun ; 4: 7, 2016 Jan 28.
Article in English | MEDLINE | ID: mdl-26822851

ABSTRACT

The original version of this article unfortunately contained a mistake in the presentation of Fig. 1 in both the PDF and HTML versions of this manuscript [1]. In the right panel of the corrected Fig. 1d, the images of Mock cells, which were visualized with GFP and stained with Abeta oligomer-specific antibody 11A1, were replaced with those of APPWT cells, and instead the images of APPWT cells were replaced with those of Mock cells. These images had been incorrectly placed in the original Fig. 1. The correct version of Fig. 1 is presented below.

5.
Nat Mater ; 13(2): 151-6, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24240243

ABSTRACT

Over the past few years, single-photon generation has been realized in numerous systems: single molecules, quantum dots, diamond colour centres and others. The generation and detection of single photons play a central role in the experimental foundation of quantum mechanics and measurement theory. An efficient and high-quality single-photon source is needed to implement quantum key distribution, quantum repeaters and photonic quantum information processing. Here we report the identification and formation of ultrabright, room-temperature, photostable single-photon sources in a device-friendly material, silicon carbide (SiC). The source is composed of an intrinsic defect, known as the carbon antisite-vacancy pair, created by carefully optimized electron irradiation and annealing of ultrapure SiC. An extreme brightness (2×10(6) counts s(-1)) resulting from polarization rules and a high quantum efficiency is obtained in the bulk without resorting to the use of a cavity or plasmonic structure. This may benefit future integrated quantum photonic devices.

6.
Int Angiol ; 32(1): 67-73, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23435394

ABSTRACT

AIM: The aim of this study was to analyze the clinical characteristics, operative management and early and late outcomes of Inflammatory abdominal aortic aneurysms (IAAAs) in our vascular service, retrospectively and to compare with the outcomes of open and endovascular aneurysm repair (EVAR) in the patients with IAAAs in literature reviews. METHODS: Between January 1990 and December 2011, this series included twenty-four patients with IAAAs who underwent surgical treatment. The mean length of follow-up was 37.6 months (range 3-108). Kaplan-Meier life tables were used to calculate survival rate. RESULTS: Fifteen patients (60%) were symptomatic including 3 patients with hydronephrosis. Seven patients with severe symptoms underwent emergency operations. Twenty four patients underwent open surgical AAA repair. The 30 - day mortality rates were 0%. All patients had successful post operative courses and followed as outpatients in an elective situation. The ten year cumulative survival rate was 70%. The early and late mortality was the same for open repair compared to non-inflammatory AAA. CONCLUSIONS: IAAA compared with non-IAAA is associated with a higher incidence of preoperative morbidity, however operative mortality rates are lower. EVAR has lower early operative mortality rates, however, there are some problems such as remaining periaortic fibrosis and hydronephrosis in approximately half of IAAA patients after EVAR.


Subject(s)
Aortic Aneurysm, Abdominal/surgery , Aortitis/surgery , Endovascular Procedures , Aged , Aged, 80 and over , Aortic Aneurysm, Abdominal/complications , Aortitis/complications , Female , Humans , Male , Middle Aged , Retrospective Studies , Time Factors , Treatment Outcome , Vascular Surgical Procedures
7.
Phys Rev Lett ; 109(18): 187603, 2012 Nov 02.
Article in English | MEDLINE | ID: mdl-23215331

ABSTRACT

Using electron paramagnetic resonance (EPR), energy levels of the carbon vacancy (V(C)) in 4H-SiC and its negative-U properties have been determined. Combining EPR and deep-level transient spectroscopy we show that the two most common defects in as-grown 4H-SiC--the Z(1/2) lifetime-limiting defect and the EH(7) deep defect--are related to the double acceptor (2-|0) and single donor (0|+) levels of V(C), respectively.

8.
Br J Radiol ; 85(1017): e622-9, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22422390

ABSTRACT

OBJECTIVES: The objective of this study was to evaluate the imaging capabilities of chest digital tomosynthesis (DT) as a screening method for the detection of artificial pulmonary nodules, and to compare its efficiency with that of CT. METHODS: DT and CT were used to detect artificial pulmonary nodules (5 mm and 8 mm in diameter, ground-glass opacities) placed in a chest phantom. Using a three-dimensional filtered back-projection algorithm at acquisition angles of 8°, 20°, 30° and 40°, DT images of the desired layer thicknesses were reconstructed from the image data acquired during a single tomographic scan. Both standard and sharp CT reconstruction kernels were used, and the detectability index (DI) valves computed for both the DT scan acquisition angles and CT reconstruction kernel types were considered. For the observer study, we examined 50 samples of artificial pulmonary nodules using both DT and CT imaging. On the basis of evaluations made by five thoracic radiologists, a jackknife free-response receiver operating characteristic (JAFROC) study was performed to compare and assess the differences in detection accuracy between CT and DT imaging. RESULTS: For each increased acquisition angle, DI obtained by DT imaging was similar to that obtained by CT imaging. The difference in the observer-averaged JAFROC figure of merit for the five readings was 0.0363 (95% confidence interval: -0.18, 0.26; F=0.101; p=0.75). CONCLUSION: With the advantages of a decreased radiation dose and the practical accessibility of examination, DT may be a useful alternative to CT for the detection of artificial pulmonary nodules.


Subject(s)
Mass Screening/methods , Phantoms, Imaging , Radiographic Image Enhancement/methods , Radiography, Thoracic/methods , Solitary Pulmonary Nodule/diagnostic imaging , Humans , Mass Screening/instrumentation , Radiographic Image Enhancement/instrumentation , Radiography, Thoracic/instrumentation , Reproducibility of Results , Sensitivity and Specificity
9.
Phys Rev Lett ; 107(22): 220501, 2011 Nov 25.
Article in English | MEDLINE | ID: mdl-22182018

ABSTRACT

We report the experimental realization of a hybrid quantum circuit combining a superconducting qubit and an ensemble of electronic spins. The qubit, of the transmon type, is coherently coupled to the spin ensemble consisting of nitrogen-vacancy centers in a diamond crystal via a frequency-tunable superconducting resonator acting as a quantum bus. Using this circuit, we prepare a superposition of the qubit states that we store into collective excitations of the spin ensemble and retrieve back into the qubit later on. These results constitute a proof of concept of spin-ensemble based quantum memory for superconducting qubits.

10.
Osteoarthritis Cartilage ; 19(1): 51-7, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21044694

ABSTRACT

OBJECTIVE: To investigate relationship between serum hyaluronan (HA) level and the presence and severity of radiographic knee osteoarthritis (OA) as well as degree of knee pain in Japanese population. DESIGN: A total of 616 volunteers participated in this study. Based on the Kellgren-Lawrence (K-L) grade, participants were radiographically classified into three groups: Normal (K-L grade 0 or 1), Moderate (grade 2) and Severe (grade 3 or 4). The degree of knee pain was quantified by visual analogue scale (VAS) and Knee injury and Osteoarthritis Outcome Score (KOOS) Pain. Serum HA levels were compared among the Normal, Moderate and Severe groups, and the relationship between serum HA level and the severity of knee OA was analyzed after age, sex and body mass index (BMI) were adjusted. In addition, the correlation between serum HA level and the degree of knee pain was analyzed in each group. RESULTS: Regarding relationship between serum HA level and the severity of radiographic knee OA, serum HA levels of the Moderate and Severe groups were significantly higher than in the Normal group (P<0.001). Furthermore, serum HA level correlated with the severity of radiographic knee OA (r=0.289, P<0.001) after adjusting for age, sex and BMI. Serum HA level correlated with VAS of knee pain and/or KOOS Pain in the Normal and Moderate groups. CONCLUSION: Serum HA level has the potential to be useful for the diagnosis of the presence and severity of knee OA.


Subject(s)
Asian People , Hyaluronic Acid/blood , Osteoarthritis, Knee/blood , Pain/etiology , Aged , Aging/blood , Biomarkers/blood , Female , Humans , Japan , Knee Joint/diagnostic imaging , Male , Middle Aged , Osteoarthritis, Knee/diagnostic imaging , Osteoarthritis, Knee/ethnology , Pain/diagnosis , Pain Measurement , Quality of Life , Radiography , Severity of Illness Index
11.
J Phys Condens Matter ; 22(38): 384202, 2010 Sep 29.
Article in English | MEDLINE | ID: mdl-21386536

ABSTRACT

First-principles calculations were performed to investigate the optical property of blue silicate phosphor, CMS:Eu. The optical absorption property is discussed based on electronic band structure and density of states. Our calculation results indicate that hybridization of the wavefunction plays an important role for nonradiative migration of electrons and holes. The calculated optical absorption spectrum could reproduce the optical features of the experimental excitation spectrum. It is also demonstrated that a practical approach using computational materials screening is effective in phosphor materials development.

12.
J Food Sci ; 73(9): H229-34, 2008 Nov.
Article in English | MEDLINE | ID: mdl-19021806

ABSTRACT

The effects of cellulose and the interindividual variations on the transit time in the small intestine remain unclear, but no previous study has to date taken these factors into sufficient consideration. We assessed the oro-ileal transit time and the recovery percentage of cellulose in the terminal ileum looking at interindividual variations. Seven healthy males received 100 mL of a dietary fiber-free basal diet with 5 g cellulose and 5 g of polyethylene glycol 4000. The ileal contents were aspirated every 30 min via an experimental tube placed in the terminal ileum to assess the oro-ileal transit time and the recovery percentage of cellulose. The mean percentage (with standard deviation) of the amounts of cellulose collected in the terminal ileum was 98.4%+/- 16.5% (ranging from 67.4% to 114.5%) with a coefficient variation of 16.8%. The average times (in hours) taken for 20%, 40%, 60%, and 80% of cellulose to reach the terminal ileum were 5.5 +/- 1.1, 6.7 +/- 0.7, 8.5 +/- 1.3, and 8.8 +/- 1.2, respectively, with large interindividual variations. In conclusion, the averaged recovery percentage of cellulose in the terminal ileum was approximately 100%, in accordance with the present generally accepted definition of dietary fiber. However, there were large interindividual variations in the oro-ileal transit time and the percentage of cellulose recovered.


Subject(s)
Cellulose , Gastrointestinal Transit , Adult , Cecum/metabolism , Cellulose/analysis , Cellulose/metabolism , Dietary Fiber , Endoscopy , Glucose/metabolism , Humans , Ileum/metabolism , Intestine, Small/metabolism , Intubation/methods , Male , Reference Values , Young Adult
13.
Br J Sports Med ; 42(4): 255-9, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18390768

ABSTRACT

OBJECTIVES: To clarify the effects of high-intensity and high-frequency long-term/chronic training on neutrophil function and serum levels of myogenic enzymes in male university judoists. METHODS: The subjects were 24 male judoists who had stopped judo training for 6 months and then restarted their training. The following parameters were examined before and after a 2 h unified exercise loading (UEL) at the beginning of the restarted quotidian training (pre-training) and at 2 months, 4 months and 6 months thereafter: myogenic enzymes, neutrophil and leucocyte counts, and neutrophil phagocytic activity (PA) and oxidative burst activity as a measure of reactive oxygen species (ROS) production capability. RESULTS: Myogenic enzymes that were measured after UEL at all four points significantly increased except for creatine kinase at the 2-month point (p<0.01 in each) and neutrophil counts significantly increased after UEL at the pre-training, 2-month and 4-month points (p<0.01 in each), but these changes became smaller from the 2-month point. PA significantly decreased after UEL at the pre-training and 2-month points (p<0.01 in each), but no change was seen at the 4-month and 6-month points. On the other hand, no change in ROS production per cell after UEL was seen at the pre-training point, but it significantly increased after UEL at the 2-month, 4-month and 6-month points (p<0.01 in each). CONCLUSION: The changing rate of the levels of UEL-mediated myogenic enzymes, neutrophil mobilisation and neutrophil function was seen to decrease at the 2-month, 4-month and 6-month assessments, compared with the pre-training point: these may comprise at least some of the long-term training effects.


Subject(s)
Martial Arts/physiology , Muscle, Skeletal/enzymology , Neutrophils/physiology , Adolescent , Anthropometry , Aspartate Aminotransferases/blood , Body Composition , Creatine Kinase/blood , Flow Cytometry , Humans , L-Lactate Dehydrogenase/blood , Leukocyte Count , Male , Phagocytosis/physiology , Physical Education and Training/methods , Reactive Oxygen Species/metabolism , Respiratory Burst/physiology , Time Factors
14.
Arch Androl ; 53(2): 53-8, 2007.
Article in English | MEDLINE | ID: mdl-17453680

ABSTRACT

The effect of sample collection site on semen parameters in ten men aged between 22 and 24 years was investigated. Sperm was collected at two sites: in a university hospital restroom for general use and in a one-person hospital room. Samples were collected from the same individual twice, with an interval of two weeks between collections. Semen parameters for the two sites were compared. Samples were collected after a minimum of three days and not longer than seven days of sexual abstinence. Sperm concentration did not differ significantly between the university hospital restroom location (86.8 +/- 25.4 x 10(6)/ml; mean +/- standard deviation) and the private hospital room (97.1 +/- 72.0 x 10(6)/ml). There was no difference in the total motile sperm count or daily sperm production between the collection sites. These results suggest that the collection site has little effect on semen parameters.


Subject(s)
Semen/physiology , Spermatozoa/cytology , Adult , Humans , Male , Sexual Abstinence , Specimen Handling , Sperm Count , Sperm Motility , Time Factors
15.
Br J Sports Med ; 41(1): 13-8, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17035481

ABSTRACT

AIMS: To evaluate the influences of the accumulative effect of two consecutive rugby sevens matches (Sevens) on aspects of human neutrophil-related non-specific immunity. METHODS: In seven players participating in the Japan Sevens, neutrophil reactive oxygen species (ROS) production capability and phagocytic activity were measured using flow cytometry, and serum opsonic activity (SOA) was assessed by measuring neutrophil ROS using the peak height of lucigenin-dependent chemiluminescence before and after two consecutive matches. RESULTS: ROS showed no change immediately after the first match, and had significantly (P<0.05) increased 4 h later, but showed a decrease after the second match. Phagocytic activity showed no change immediately after the first match, but had significantly (P<0.01) decreased 4 h later, and showed a further decrease after the second match, although it was not significant. SOA significantly (P<0.01) increased after the first match, and still maintained its high 4 h later, but decreased after the second match. ROS production capability, phagocytic activity and SOA significantly (P<0.01) decreased after the second match. CONCLUSIONS: When rugby players play two consecutive Sevens matches, the exercise loading is thought to be hard, similar to that experienced during a marathon race and intensive or long training in a training camp, although the expected changes were not seen after the first match. Differences between after the first and the second matches may be due to the "cumulative effect".


Subject(s)
Football/physiology , Immunity, Innate/immunology , Neutrophils/immunology , Reactive Oxygen Species/immunology , Adult , Flow Cytometry , Humans , Japan , Leukocyte Count , Phagocytosis/immunology , Risk Factors
16.
Cephalalgia ; 26(8): 1010-5, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16886938

ABSTRACT

We semiquantitatively analysed radionuclide cisternography in three patients with spontaneous cerebrospinal fluid (CSF) leakage diagnosed by typical symptoms and magnetic resonance imaging findings before and several months after treatment with epidural blood patch. Radioactivity in the whole CSF space was measured immediately after and at 1, 5, 7 and 24 h after intrathecal injection of (111)In-diethylenetriaminepentaacetic acid (DTPA). Initial findings included the vague appearance of leakage in the thoracic spine in two patients, early bladder filling at 1 h in one and a lack of tracer filling into the high cranial convexity in all three. The radioactivity count rapidly decreased within several hours after injection and reached 20% of the initial value at 24 h. In contrast, no rapid decrease was observed after treatment and more than 50% of tracer remained at 24 h after injection. Semiquantitative analysis of tracer clearance may provide additional information in the diagnosis of CSF leakage, especially with no obvious qualitative findings.


Subject(s)
Intracranial Hypotension/cerebrospinal fluid , Intracranial Hypotension/diagnostic imaging , Octreotide/analogs & derivatives , Pentetic Acid/analogs & derivatives , Subdural Effusion/cerebrospinal fluid , Subdural Effusion/diagnostic imaging , Female , Humans , Intracranial Hypotension/etiology , Male , Metabolic Clearance Rate , Middle Aged , Myelography/methods , Octreotide/cerebrospinal fluid , Pentetic Acid/cerebrospinal fluid , Radioisotope Dilution Technique , Radionuclide Imaging , Radiopharmaceuticals/cerebrospinal fluid , Reproducibility of Results , Sensitivity and Specificity , Subdural Effusion/complications
17.
J Anim Physiol Anim Nutr (Berl) ; 90(5-6): 208-15, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16684141

ABSTRACT

Obesity in dogs and cats have been increasingly recognized in recent years. Because obesity underlies various diseases, pet owners and veterinarians have an important responsibility to help animals lose weight and maintain their health. Diet therapy, however, is typically based on limited calorie intake and animals may suffer stress from hunger and this is also a concern to animal owners. For this reason, many clients drop out of weight control programmes. In the present study, we focused on dietary diacylglycerol (DAG) as a potentially effective ingredient for canine weight control without caloric restriction. We replaced a portion of the fat in dog food with either DAG or triacylglycerol (TAG), referred to as DAG or TAG diets here, and fed overweight beagle dogs (body condition score of 4 or higher) with either the DAG or TAG diet for a 6-week period. Results indicated that, even though the food composition other than fat type were identical, dogs fed the DAG diet showed a statistically significant reduction in body weight averaging a 2.3% reduction within 6 weeks while the TAG-fed dogs maintained their obese body weights. In addition, the DAG group also showed a reduction in body fat content, serum triglyceride and total cholesterol concentrations. These results suggest the possibility of developing a pet food using DAG to control weight and serum lipid levels without compromising caloric intake.


Subject(s)
Diglycerides/therapeutic use , Dog Diseases/diet therapy , Lipids/blood , Obesity/veterinary , Weight Loss/drug effects , Animals , Cross-Over Studies , Diglycerides/administration & dosage , Dogs , Female , Male , Obesity/diet therapy , Treatment Outcome , Triglycerides/administration & dosage , Triglycerides/therapeutic use
18.
Phys Rev Lett ; 96(14): 145501, 2006 Apr 14.
Article in English | MEDLINE | ID: mdl-16712089

ABSTRACT

The metastability of vacancies was theoretically predicted for several compound semiconductors alongside their transformation into the antisite-vacancy pair counterpart; however, no experiment to date has unambiguously confirmed the existence of antisite-vacancy pairs. Using electron paramagnetic resonance and first principles calculations we identify the S15 center as the carbon antisite-vacancy pair in the negative charge state (C(Si)V-(C)) in 4H-SiC. We suggest that this defect is a strong carrier-compensating center in n-type or high-purity semi-insulating SiC.

19.
Phys Rev Lett ; 96(5): 055501, 2006 Feb 10.
Article in English | MEDLINE | ID: mdl-16486945

ABSTRACT

Electron paramagnetic resonance and ab initio supercell calculations suggest that the P6/P7 centers, which were previously assigned to the photoexcited triplet states of the carbon vacancy-antisite pairs in the double positive charge state, are related to the triplet ground states of the neutral divacancy. The spin density is found to be located mainly on three nearest C neighbors of the silicon vacancy, whereas it is negligible on the nearest Si neighbors of the carbon vacancy.

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