511 keV γ\gamma-ray emission from the galactic bulge by MeV millicharged dark matter

We propose a possible explanation for the recently observed anomalous 511 keV line with a new "millicharged" fermion. This new fermion is light [${\cal O}({\rm MeV})$]. Nevertheless, it has never been observed by any collider experiments by virtue of its tiny electromagnetic charge $\epsilon e$. In particular, we constrain parameters of this millicharged particle if the 511 keV cosmic $\gamma$-ray emission from the galactic bulge is due to positron production from this new particle.Comment: 3 pages, 1 figure, A talk given by J.C.Park at the 16th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY08), Seoul, Korea, June 16-21, 200

Real-time delay-multiply-and-sum beamforming with coherence factor for in vivo clinical photoacoustic imaging of humans

In the clinical photoacoustic (PA) imaging, ultrasound (US) array transducers are typically used to provide B-mode images in real-time. To form a B-mode image, delay-and-sum (DAS) beamforming algorithm is the most commonly used algorithm because of its ease of implementation. However, this algorithm suffers from low image resolution and low contrast drawbacks. To address this issue, delay-multiply-and-sum (DMAS) beamforming algorithm has been developed to provide enhanced image quality with higher contrast, and narrower main lobe compared but has limitations on the imaging speed for clinical applications. In this paper, we present an enhanced real-time DMAS algorithm with modified coherence factor (CF) for clinical PA imaging of humans in vivo. Our algorithm improves the lateral resolution and signal-to-noise ratio (SNR) of original DMAS beam-former by suppressing the background noise and side lobes using the coherence of received signals. We optimized the computations of the proposed DMAS with CF (DMAS-CF) to achieve real-time frame rate imaging on a graphics processing unit (GPU). To evaluate the proposed algorithm, we implemented DAS and DMAS with/without CF on a clinical US/PA imaging system and quantitatively assessed their processing speed and image quality. The processing time to reconstruct one B-mode image using DAS, DAS with CF (DAS-CF), DMAS, and DMAS-CF algorithms was 7.5, 7.6, 11.1, and 11.3 ms, respectively, all achieving the real-time imaging frame rate. In terms of the image quality, the proposed DMAS-CF algorithm improved the lateral resolution and SNR by 55.4% and 93.6 dB, respectively, compared to the DAS algorithm in the phantom imaging experiments. We believe the proposed DMAS-CF algorithm and its real-time implementation contributes significantly to the improvement of imaging quality of clinical US/PA imaging system.11Ysciescopu

Inelastic scattering in a monolayer graphene sheet; a weak-localization study

Charge carriers in a graphene sheet, a single layer of graphite, exhibit much distinctive characteristics to those in other two-dimensional electronic systems because of their chiral nature. In this report, we focus on the observation of weak localization in a graphene sheet exfoliated from a piece of natural graphite and nano-patterned into a Hall-bar geometry. Much stronger chiral-symmetry-breaking elastic intervalley scattering in our graphene sheet restores the conventional weak localization. The resulting carrier-density and temperature dependence of the phase coherence length reveal that the electron-electron interaction including a direct Coulomb interaction is the main inelastic scattering factor while electron-hole puddles enhance the inelastic scattering near the Dirac point.Comment: 12 pages, 3 figures, submitted to PR

Benign metastasizing leiomyoma of the lung

Benign leiomyomas of the uterus are uncommonly found in association with benign smooth muscle tumors beyond the confines of the uterus. Benign metastasizing leiomyoma (BML) is a rare disease in which the lung is described to be the most afflicted extrauterine organ. We present a brief review of the literature, along with case reports for four patients who were followed up after resection of a pulmonary lesion or after pathological confirmation by biopsy. The clinical course of BML varies from chronic asymptomatic appearance to rapid progression, leading to respiratory failure and death. Our BML patients did not complain of pulmonary symptoms, such as cough, dyspnea, or chest tightness. Pathology revealed benign leiomyomas with no atypia and mitotic activity <5 per 10 high-power field. Immunohistochemical staining was positive for actin and desmin. A standard treatment for BML has not yet been established. Because of the hormone-sensitive characteristics of BML, treatments are based on hormonal manipulation along with either surgical or medical oophorectomy. Benign metastasizing leiomyoma can be observed in postmenopausal women. We observed four patients who did not receive adjuvant hormonal therapy because they were postmenopausal or perimenopausal. All patients are still healthy and show no evidence of recurrence or progression of the disease

Influence of mixed alkali oxides on some melt properties of TV screen glass

The influence of K2O/R2O (R2O = Na2O+K2O) on some melt properties was studied in alkali-alkaline earth-silicate TV screen glasses. Viscosity, surface tension, electrical resistivity, volatilization and devitrification of glass melts were determined. No mixed alkali effect was observed in viscosity, surface tension and liquidus temperature. They showed a linear behavior with increase of K2O/R2O. On the other hand, electrical resistivity and weight loss by volatilization showed a strong mixed alkali effect against relative alkali concentration. According to the dependence of viscosity, electrical resistivity and volatilization on K2O/R2O, the slope change of those properties took place at K2O/R2O = 0.4 to ≈ 0.5. The compositional dependence of viscosity, surface tension and liquidus temperature was discussed in terms of field strength, polarizability and material diffusion, respectively. Α correlation was also discussed between the dependence of properties on K2O/R2O and the production process of TV screen glass. In conclusion, from the viewpoint of both production and application of TV glasses it was suggested that the mole fraction of K2O/R2O should lie between 0.2 and 0.5

Impacts of Heavy Rain and Typhoon on Allergic Disease

AbstractObjectivesAllergic disease may be increased by climate change. Recent reports have shown that typhoon and heavy rain increase allergic disease locally by concentration of airborne allergens of pollen, ozone, and fungus, which are causes of allergic disease. The objective of this study was to determine whether typhoon and heavy rain increase allergic disease in Korea.MethodsThis study included allergic disease patients of the area declared as a special disaster zone due to storms and heavy rains from 2003 to 2009. The study used information from the Korea Meteorological Administration, and from the National Health Insurance Service for allergic diseases (asthma, allergic rhinitis, and atopic dermatitis).ResultsDuring a storm period, the numbers of allergy rhinitis and atopic dermatitis outpatients increased [rate ratio (RR) = 1.191; range, 1.150–1.232] on the sixth lag day. However, the number of asthma outpatients decreased (RR = 0.900; range, 0.862–0.937) on the sixth lag day after a disaster period. During a storm period, the numbers of allergic rhinitis outpatients (RR = 1.075; range, 1.018–1.132) and atopy outpatients increased (RR = 1.134; range, 1.113–1.155) on the seventh lag day. However, the number of asthma outpatients decreased to RR value of 0.968 (range, 0.902–1.035) on the fifth lag day.ConclusionThis study suggests that typhoon and heavy rain increase allergic disease apart from asthma. More study is needed to explain the decrease in asthma

Catalytic pyrolysis of Laminaria japonica over nanoporous catalysts using Py-GC/MS

The catalytic pyrolysis of Laminaria japonica was carried out over a hierarchical meso-MFI zeolite (Meso-MFI) and nanoporous Al-MCM-48 using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The effect of the catalyst type on the product distribution and chemical composition of the bio-oil was examined using Py-GC/MS. The Meso-MFI exhibited a higher activity in deoxygenation and aromatization during the catalytic pyrolysis of L. japonica. Meanwhile, the catalytic activity of Al-MCM-48 was lower than that of Meso-MFI due to its weak acidity

Isolation and characterization of a new mucoid-free Klebsiella pneumoniae strain for 2,3-butanediol production

The secretion of mucoid substances by Klebsiella pneumoniae, a natural 2,3-butanediol (2,3-BD) hyper-producer, hinders its application in large-scale fermentation because of pathogenicity, fermentation instability, and downstream difficulty. In this study, 14 K. pneumoniae strains were isolated from a waste water treatment plant and their 2,3-BD production efficiencies were assessed with the strain K. pneumoniae DSM2026. Among various strains isolated, K. pneumoniae GSC010 and GSC112 produced relatively large amounts of 2,3-BD compared to other isolates; and their 2,3-BD production was consistent with DSM2026. Meanwhile, mucoidic characteristics of GSC010 were more or less similar to DSM2026, which was observed by scanning electron microscope (SEM) as a characteristic intercalated thread anchored on the surface of the cells. However, no polysaccharide materials were found in a non-mucoid cell, GSC112. Fed-batch culture of GSC112 with continuous glucose feeding resulted in the production of 2,3-BD at 52.4 g/l with 2,3-BD yield and overall productivity of 0.27 g/g glucose and 0.52 g/l/h, respectively. These results strongly suggest that the newly isolated mucoid-free K. pneumoniae GSC112 has potential for industrial production of 2,3-BD.Keywords: 2,3-Butanediol, Klebsiella pneumoniae, isolation, capsular polysaccharides, scanning electron microscop