203 research outputs found
Steady solution and its stability to Navier-Stokes equations with general Navier slip boundary condition
Steady solution and asymptotic behaviour of corresponding nonsteady solution are studied for the Navier-Stokes equations under general Navier slip boundary condition. It is proved that the existence of a unique stationary solution and that this solution is asymptotically stable under some restrictions of the data
DWT Domain On-line Signature Verification Using Pen-movement Vector
We examine a pen-movement vector parameter to reduce the computational complexity in the on-line signature verification method based on DiscreteWavelet Transform (DWT) and adaptive signal processing. The pen-movement vector is a time-varying signal which is derived from pen-position parameters and is decomposed into sub-band signals by using the DWT. Individual features are extracted as high frequency components in sub-bands. Verification is achieved in each sub-band by using the adaptive signal processing. Total decision for verification is done by combining multiple verification results. Experimental results show that the verification rate using the pen-movement vector parameter is equivalent to that of our conventional method which utilizes the pen-position parameter although computational complexity is reduced to half of that of the conventional method
Traditional Herbal Medicine, Rikkunshito, Induces HSP60 and Enhances Cytoprotection of Small Intestinal Mucosal Cells as a Nontoxic Chaperone Inducer
Increasing incidence of small intestinal ulcers associated with nonsteroidal anti-inflammatory drugs (NSAIDs) has become a topic with recent advances of endoscopic technology. However, the pathogenesis and therapy are not fully understood. The aim of this study is to examine the effect of Rikkunshito (TJ-43), a traditional herbal medicine, on expression of HSP60 and cytoprotective ability in small intestinal cell line (IEC-6). Effect of TJ-43 on HSP60 expression in IEC-6 cells was evaluated by immunoblot analysis. The effect of TJ-43 on cytoprotective abilities of IEC-6 cells against hydrogen peroxide or indomethacin was studied by MTT assay, LDH-release assay, caspase-8 activity, and TUNEL. HSP60 was significantly induced by TJ-43. Cell necrosis and apoptosis were significantly suppressed in IEC-6 cells pretreated by TJ-43 with overexpression of HSP60. Our results suggested that HSP60 induced by TJ-43 might play an important role in protecting small intestinal epithelial cells from apoptosis and necrosis in vitro
Correlation of Heat Shock Protein Expression to Gender Difference in Development of Stress-Induced Gastric Mucosal Injury in Rats
Recent studies have indicated that heat shock proteins (HSPs), which function as molecular chaperones, play important roles in cellular responses to stress-related events. However, the gender difference in the expression of HSP in the gastric mucosa remains unclear. In order to understand the mechanism of gender difference in the prevalence or severity of gastric mucosal lesions, the expression level of HSP and the correlation of estrogen to HSP induction in the gastric mucosa were evaluated in this study. The basal expression levels of HSP60 and HSP90 in the gastric mucosa were significantly higher in females than those in males. The gastric ulcer index was significantly higher in male rats compared to female rats observed after 12 h water immersion stress exposure. At this time point, the expression levels of HSP60 and HSP90 in the gastric mucosa were significantly higher in females than those in males. An estrogen-treatment significantly induced the expression of HSP60, HSP70 and HSP90 in the gastric mucosa. Inversely, an ovariectomy dramatically reduced the expression of HSP60, HSP70 and HSP90 in the gastric mucosa. Our results suggested that estrogen might play an important role in gastric mucosal protection with the induction of gastric mucosal HSPs
A Young Brown Dwarf Companion to DH Tauri
We present the detection of a young brown dwarf companion DH Tau B associated
with the classical T Tauri star DH Tau. Near-infrared coronagraphic
observations with CIAO on the Subaru Telescope have revealed DH Tau B with H =
\~15 mag located at 2.3" (330 AU) away from the primary DH Tau A. Comparing its
position with a Hubble Space Telescope archive image, we confirmed that DH Tau
A and B share the common proper motion, suggesting that they are physically
associated with each other. The near-infrared color of DH Tau B is consistent
with those of young stellar objects. The near-infrared spectra of DH Tau B show
deep water absorption bands, a strong K I absorption line, and a moderate Na I
absorption line. We derived its effective temperature and surface gravity of
Teff = 2700 -- 2800 K and log g = 4.0--4.5, respectively, by comparing the
observed spectra with synthesized spectra of low-mass objects. The location of
DH Tau B on the HR diagram gives its mass of 30 -- 50 M_Jupiter.Comment: 10 pages, 14 figures, 1 table, accepted for publication in Ap
Tailored Synthesis of 162-Residue S-Monoglycosylated GM2-Activator Protein (GM2AP) Analogues that Allows Facile Access to Protein Library
A synthetic protocol has been developed for the preparation of 162-residue S-monoglycosylated GM2-activator protein (GM2AP) analogues bearing various amino acid substitutions for Thr69. The facile incorporation of the replacements into the protein was achieved by a one-pot/N–to–C-directed sequential ligation strategy using readily accessible middle N-sulfanylethylanilide (SEAlide) peptides consisting of seven amino acid residues. A kinetically-controlled ligation protocol was successfully applied to the assembly of three peptide segments covering the GM2AP. The native chemical ligation (NCL) reactivities of the SEAlide can be tuned by the presence or absence of phosphate salts. Furthermore, the NCL of the alkyl thioester fragment (GM2AP (1–31)) with the N-terminal cysteinyl prolyl thioester (GM2AP (32–67)) proceeded smoothly to yield the 67-residue prolyl thioester, with the prolyl thioester moiety remaining intact. This newly developed strategy enabled the facile synthesis of GM2AP analogues. Thus, we refered this synthetic protocol as “Tailored Synthesis” for the construction of a GM2AP library
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