853 research outputs found
3D cut-cell modelling for high-resolution atmospheric simulations
Owing to the recent, rapid development of computer technology, the resolution
of atmospheric numerical models has increased substantially. With the use of
next-generation supercomputers, atmospheric simulations using horizontal grid
intervals of O(100) m or less will gain popularity. At such high resolution
more of the steep gradients in mountainous terrain will be resolved, which may
result in large truncation errors in those models using terrain-following
coordinates. In this study, a new 3D Cartesian coordinate non-hydrostatic
atmospheric model is developed. A cut-cell representation of topography based
on finite-volume discretization is combined with a cell-merging approach, in
which small cut-cells are merged with neighboring cells either vertically or
horizontally. In addition, a block-structured mesh-refinement technique is
introduced to achieve a variable resolution on the model grid with the finest
resolution occurring close to the terrain surface. The model successfully
reproduces a flow over a 3D bell-shaped hill that shows a good agreement with
the flow predicted by the linear theory. The ability of the model to simulate
flows over steep terrain is demonstrated using a hemisphere-shaped hill where
the maximum slope angle is resolved at 71 degrees. The advantage of a locally
refined grid around a 3D hill, with cut-cells at the terrain surface, is also
demonstrated using the hemisphere-shaped hill. The model reproduces smooth
mountain waves propagating over varying grid resolution without introducing
large errors associated with the change of mesh resolution. At the same time,
the model shows a good scalability on a locally refined grid with the use of
OpenMP.Comment: 19 pages, 16 figures. Revised version, accepted for publication in
QJRM
The Physiological Roles of Leptin in Skin Wound Healing
Leptin, a 16 kDa circulating anti-obesity hormone, has many physiological properties such as body weight homeostasis, lipid metabolism, hematopoiesis, thermogenesis, ovarian function, bone formation, and angiogenesis. Interestingly, a certain study showed that skin wound healing delayed in leptin deficient ob/ob mice. However, little has been known about the physiological role of leptin in skin wound healing. In this chapter, we introduce whether local and single-dose administration of leptin exerted a promotive influence on the skin wound healing. Immunohistochemical analysis revealed that leptin receptor was expressed in mouse epidermal cells. In addition, topical administration of leptin promoted the healing of chemical burn wounds created on the back skin of mice without any side effects. Then, the mechanisms of the promotive effect of leptin on the wound healing of the skin were demonstrated immunohistochemical and biological analysis; namely, leptin stimulated angiogenesis in the connective tissue beneath the wounded area and the cell proliferation, differentiation/function, and migration of human epidermal keratinocytes. These findings revealed the possible and promising usefulness of leptin as a new wound-healing promoting agent
減数分裂組換えがアカショウジョウバエのneo-Y染色体の進化に及ぼす影響
首都大学東京, 2016-03-25, 博士(理学), 甲第568号首都大学東
Rapid preparation of mutated influenza hemagglutinins for influenza virus pandemic prevention
Influenza viruses have periodically caused pandemic due to frequent mutation of viral proteins. Influenza viruses have two major membrane glycoproteins: hemagglutinin (HA) and neuraminidase (NA). Hemagglutinin plays a crucial role in viral entry, while NA is involved in the process of a viral escape. In terms of developing antiviral drugs, HA is a more important target than NA in the prevention of pandemic, since HA is likely to change the host specificity of a virus by acquiring mutations, thereby to increase the risk of pandemic. To characterize mutated HA functions, current approaches require immobilization of purified HA on plastic wells and carriers. These troublesome methods make it difficult to respond to emerging mutations. In order to address this problem, a yeast cell surface engineering approach was investigated. Using this technology, human HAs derived from various H1N1 subtypes were successfully and rapidly displayed on the yeast cell surface. The yeast-displayed HAs exhibited similar abilities to native influenza virus HAs. Using this system, human HAs with 190E and 225G mutations were shown to exhibit altered recognition specificities from human to avian erythrocytes. This system furthermore allowed direct measurement of HA binding abilities without protein purification and immobilization. Coupled with the ease of genetic manipulation, this system allows the simple and comprehensive construction of mutant protein libraries on yeast cell surface, thereby contributing to influenza virus pandemic prevention
The Framework Convention on Tobacco Control (FCTC) and Japanese anti-tobacco measures
Japanese anti-tobacco measures are reviewed and checked the relationship between the FCTC and its changes. Japan is making efforts to follow the FCTC, but it is insufficient and present anti-tobacco measures seem to have only a little impact on decreasing smoking rates. More effective measures should be developed for reducing smoking rates and for making smoke-free society
Usefulness of Highly Sensitive AFP-L3 and DCP in Surveillance for Hepatocellular Carcinoma in Patients with a Normal Alpha-Fetoprotein
Background and aims: Early detection of Hepatocellular Carcinoma (HCC) is crucial for effective management. Incidence of HCC has increased in the United States largely attributed to hepatitis B and C virus. Lens culinaris agglutinin-reactive Alpha-Fetoprotein (AFP-L3) and Des-Gamma-Carboxy Prothrombin (DCP) are being recognized specific biomarkers for HCC.
Methods: We measured AFP-L3 and DCP in serial serum specimens of a cohort of chronic hepatitis patients on HCC surveillance and compared these markers to abdominal imaging. Among fifty patients who developed HCC during surveillance, 30 were included in the study with available sera 1-2 years before, at diagnosis and post ablation of HCC. For controls, three consecutive annual sera were examined from 106 chronic hepatitis patients without HCC during surveillance for 5-10 years. The μTASWako i30 auto analyzer was used for the assay that utilizes the microfluidics chip based assay platform. It can fractionate AFP-L3 glycoform and calculates AFP-L3% if AFP level is ≥ 0.6 ng/mL.
Results: Combination of AFP, AFP-L3 and DCP showed high sensitivity of 83% in all patients and 75% in patients with AFP\u3c20 ng/mL. AFP-L3 and DCP assays were useful in patients with low levels of AFP (\u3c20 ng/mL) and could detect significant AFP-L3% elevation in some patients more than one year before the diagnosis of HCC. Furthermore, AFP-L3 predicted recurrence of HCC.
Conclusions: This is the first study in the U.S. patients using the μTASWako i30 analyzer to test these HCC biomarkers. Our results suggest that combinations of these biomarkers are highly useful for early detection of HCC
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