Search Results - (Author, Cooperation:I. Choi)

2018-04-27

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Geosciences

Computer Science

Medicine

Natural Sciences in General

Physics

Neuroscience

2018-05-16

National Academy of Sciences

0027-8424

1091-6490

Biology

Medicine

Natural Sciences in General

2015-07-25

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2015-10-03

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; Conditioning, Classical ; Estrogen Receptor alpha/*genetics ; Fear ; *Gene Expression Regulation ; Hippocampus/*metabolism ; Male ; Membrane Proteins/*genetics ; *Memory ; Mice ; Mice, Inbred C57BL ; Protein Biosynthesis/*genetics ; Ribosomal Proteins/genetics ; Transcription, Genetic

2013-11-05

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Adult ; Animals ; Bacteria/genetics ; Colitis, Ulcerative/enzymology/genetics/microbiology ; Crohn Disease/enzymology/genetics/microbiology ; Female ; Gene Deletion ; Gene Expression Profiling ; *Gene Expression Regulation ; Histone Deacetylases/genetics/*metabolism ; *Homeostasis ; Humans ; Intestinal Mucosa/*enzymology/pathology ; Intestines/*microbiology ; Male ; Mice ; Mice, Inbred C57BL ; Paneth Cells/cytology/metabolism ; RNA, Ribosomal, 16S/genetics ; Signal Transduction ; *Symbiosis

2018-03-15

The Company of Biologists

0950-1991

1477-9129

Biology

Musculoskeletal system

1089-7674

AIP Digital Archive

Physics

Spectra of energetic electrons in the 100 keV range were measured from the interaction of intense femtosecond laser pulses with clusters of xenon or argon. The interaction of 28 fs pulses with cluster targets revealed quite different results with respect to applied laser intensity. At the laser intensity of 1×1016 W/cm2, the absorption by xenon clusters was about 25%; however, at the laser intensity of 1×1017 W/cm2, the laser energy absorption drastically increased to 78%, and the efficient coupling between the laser pulse and cluster target produced electrons with energy as high as 500 keV. The estimated hot electron temperatures ranged from about 30 to 90 keV depending on atoms and backing pressures. © 2002 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

We investigated the effects of surface roughness and grain boundary diffusion (GBD) at elevated temperatures on the Auger-electron-spectroscopy sputter depth profiles of Co–Ag bilayers and the GBD process of Ag atoms in Co. The Ag layer in the Ag/Co bilayer is transformed from a uniform layer to discrete islands by heat treatment. Enhanced mobility during sputtering at elevated temperatures makes Ag atoms migrate continually from islands to cover neighboring exposed Co, which reduces the size of Ag islands. On the other hand, the surface morphological modification of Co/Ag bilayer does not occur by heat treatment, and the depth profile at 340 °C resembles that from a uniformly intermixed film, which shows a drastic difference from that of Ag/Co. This is explained with a very thin and stable accumulation of Ag on the Co layer by GBD. A model of structural changes in Co/Ag subjected to ion sputtering at elevated temperatures is proposed on the basis of the results. The activation energy and pre-exponential factor for GBD of Ag in Co are found to be 0.46±0.06 eV and ∼1×10−8 cm2/s, respectively. © 1996 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Cu (400 Å)/polyimide was mixed with 80 keV Ar+ and N2+ from 1.0×1015 to 2.0×1016 ions/cm2. The same processes were repeated for the Cu (400 Å)/Al (50 Å)/polyimide system which has Al as a buffer layer. The quantitative adhesion strength was measured by a standard scratch test. X-ray photoelectron spectroscopy was employed to investigate the change in the chemical bonds of the ion beam mixed polyimide substrate and the intermediate effects for the adhesion enhancement in Cu/Al/polyimide. Two distinct tendencies are observed in the adhesion strength: Cu/Al/polyimide is more adhesive than Cu/polyimide after ion beam mixing, and N2+ ions are more effective in the adhesion enhancement than Ar+. The formation of an interlayer compound of CuAl2O4 accounts for the former, while the latter is understood by the fact that N2+ ions produce more pyridinelike moiety, amide group and tertiary amine moiety which are known as adhesion promoters. © 1997 American Institute of Physics.

Electronic Resource

1398-9995

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1745-4603

Blackwell Publishing Journal Backfiles 1879-2005

Process Engineering, Biotechnology, Nutrition Technology

A mixture of partially defatted peanut flour (12% fat) and rice flour was extruded to produce indirectly, puffed extrudates using a corotating twin-screw extruder. Extrudates were dried to obtain half-products of 11-12% moisture content, and the half-products were expanded by deep-fat frying. The effects of three levels of peanut flour (30, 40, and 50%), screw speed (200, 300, and 400 rpm) and feed rate (4, 5, and 6 kg/h) were studied by characterizing the cellular structure of expanded snack products using Scanning Electron Microscopy (SEM). Average cell size (mm2) and the number of cells per unit area (cm2) were determined from the interior cross-section area of snack products. Those parameters were influenced mainly by the level of peanut flour followed by screw speed and feed rate. Increasing peanut flour from 40 to 50% produced less puffed final products resulting in small cell size compared to snacks of 30 - 40% peanut flour. The maximum cell size was produced in the snack products extruded with peanut flour of 30 - 40% at screw speed of 250 - 330 rpm and feed rate of 4.7 - 5.7 kg/h. While the number of cells was relatively similar regardless of screw speed and feed rate, increasing peanut flour increased the number of cells. The cell walls became thicker with increasing feed rate.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background Recent studies suggest that atopy may be associated with exercise-induced bronchospasm (EIB) in asthma. However, it is not clear whether atopy is related to EIB, regardless of airway hyper-responsiveness (AHR) to methacholine, because asthmatic subjects often show AHR to exercise and methacholine simultaneously.Objective To investigate whether atopy is related to EIB in asthmatic subjects, independently of AHR to methacholine.Methods Fifty-eight male asthmatic subjects were studied. Initial spirometry was performed. Skin prick test was carried out, using 53 common allergens including mites dust antigen. Atopy score was defined as a sum of mean weal diameters to all allergens tested. Methacholine bronchial provocation testing was performed. Twenty-four hours later, free running test was performed. Positive EIB was defined as a 15% reduction or more in FEV1 from baseline after exercise.Results All subjects had AHR to methacholine. The degree of AHR to methacholine in asthmatics with EIB was similar to that in asthmatics without EIB. However, atopy score and skin reaction to Dermatophagoides pteronyssinus significantly increased in asthmatics with EIB compared with those without EIB (P 〈 0.05, respectively). Furthermore, the degree of EIB significantly correlated with atopy score in all subjects (r = 0.35, P 〈 0.01). This relationship was maintained even after the exclusion of EIB-negative asthmatic subjects.Conclusion Atopy defined as skin test reactivity may contribute to the development of EIB in asthma, independently of AHR to methacholine.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background Cytokines production by T helper lymphocytes (Th cells), which orchestrate the interplay of the different cells involved in airway inflammation of asthma, may be reflected in peripheral blood. Some studies have suggested that the Th cell cytokines by peripheral blood T cells correlate with asthma severity.Objective To investigate the relationship between changes in IFN-γ production by peripheral blood T cells and changes in lung function in chronic stable asthmatics.Methods Sixteen patients with chronic stable moderate asthma aged 35–65 years (nine women) were recruited. Morning and evening peak expiratory flow rates (PEFR) monitoring and blood sampling for peripheral blood T cell culture, total IgE and blood eosinophils were performed at baseline and week 12. Levels of IFN-γ, IL-4 and IL-5 in culture supernatants of peripheral blood T cell were determined by using enzyme-linked immunosorbent assay (ELISA) kits.Results Patients with increased IFN-γ changes from baseline showed significantly increased changes in morning (P = 0.02) and evening (P 〈 0.05) PEFR compared with those with decreased IFN-γ changes. The changes in IFN-γ production and IFN-γ: IL-4 ratio significantly correlated with the changes in morning PEFR (Rs = 0.59, P 〈 0.02; Rs = 0.63, P 〈 0.01, respectively) and tended to correlate with the changes in evening PEFR (Rs = 0.45, P = 0.08; Rs = 0.5, P = 0.05, respectively). The changes in IL-4 and IL-5 did not correlate with the changes in IgE and blood eosinophils, respectively.Conclusions These findings suggest that IFN-γ may be associated with the alteration of lung function in asthmatics and play a role in the pathophysiology of chronic stable asthma.

Electronic Resource

0020-1693

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1398-9995

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background:  Proliferating cell nuclear antigen (PCNA) is a component of multiprotein complexes that are expressed during cell proliferation. Ozone induces cell necrosis and a consequent increase in cell proliferation. Methods:  To investigate the effects of acute ozone inhalation on cell proliferation and airway obstruction in BALB/C mice, we examined enhanced pause (Penh) as an index of airway obstruction and PCNA expression by immunohistochemical staining. Results:  Compared with controls that received filtered air, the ozone-exposed groups had increased PCNA expression in the alveolar epithelial cells. In rank order, the highest PCNA index was found following 2.0 p.p.m. ozone exposure. In the 2.0 p.p.m. ozone group, there was a PCNA index of 16.83 ± 0.57% (mean ± SEM; P 〈 0.01), compared with 4.25 ± 0.5% at 0.12 p.p.m., 6.83 ± 0.60 at 0.5 p.p.m and 12.16 ± 0.48% at 1 p.p.m. Following ozone exposure, Penh was increased in a dose-dependent manner. There was a significant correlation between the PCNA index in alveoli and Penh ( r  = 0.63, P 〈 0.01). Conclusions:  These data suggest that ozone can induce alveolar epithelial cell proliferation in a dose-dependent manner, and that alveolar epithelial cell proliferation is correlated with airway obstruction.

Electronic Resource

1398-9995

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1398-9995

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1365-2036

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Helicobacter pylori eradication has become the standard treatment for duodenal ulcer. However, there is no relevant evidence for antibacterial treatment of the white scar stage of duodenal ulcer (duodenal ulcer scar) in patients with no past history of duodenal ulcer.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:To investigate whether H. pylori eradication could decrease duodenal ulcer recurrence in patients with duodenal ulcer scar and no past history of duodenal ulcer.〈section xml:id="abs1-3"〉〈title type="main"〉Patients and methods:We prospectively enrolled 66 patients with duodenal ulcer scar: 53 were H. pylori-positive and 13 were H. pylori-negative. H. pylori-positive patients were randomly assigned into two groups (two-to-one allocation): 36 patients were assigned to the treatment group and 17 to the follow-up group. Thirteen H. pylori-negative patients were followed up according to the study protocol. Follow-up endoscopy was performed to evaluate ulcer scar changes and H. pylori status 6 weeks after anti-H. pylori treatment and then every 6 months for up to 30 months.〈section xml:id="abs1-4"〉〈title type="main"〉Results:Active duodenal ulcer recurrence was identified in seven of 23 H. pylori-positive/non-cured patients (30%). There was no duodenal ulcer recurrence in 43 H. pylori-negative/cured patients (0%), which was significantly different in terms of duodenal ulcer recurrence (P=0.001).〈section xml:id="abs1-5"〉〈title type="main"〉Conclusions: H. pylori eradication is effective at preventing active duodenal ulcer recurrence in patients with duodenal ulcer scar and no past history of duodenal ulcer.

Electronic Resource

1365-2036

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Proton pump inhibitor-based triple therapies are recommended as the first-line treatment for Helicobacter pylori eradication.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:To evaluate the efficacies of low-dose clarithromycin triple therapy and tinidazole-containing triple therapy in a metronidazole resistance prevalent area and to compare the efficacies with standard triple therapy.〈section xml:id="abs1-3"〉〈title type="main"〉Methods:In a randomized, multicentre, prospective study, a total of 352 patients with duodenal ulcer or non-ulcer dyspepsia were randomly divided into three groups according to the administered regimen: OAC250 group (omeprazole, 20 mg, amoxicillin, 1000 mg, and clarithromycin, 250 mg), OAC500 group (omeprazole, 20 mg, amoxicillin, 1000 mg, and clarithromycin, 500 mg) and OTC group (omeprazole, 20 mg, tinidazole, 500 mg, and clarithromycin, 500 mg). The three groups received each regimen twice daily for 7 days. Upper gastrointestinal endoscopy was performed before and 4 weeks after treatment. H. pylori status was determined by rapid urease test and 13C urea breath test.〈section xml:id="abs1-4"〉〈title type="main"〉Results:The eradication rates in the OAC250, OAC500 and OTC groups were 76.2%, 65.7% and 64.8% (95% confidence interval: 67.9–84.4%, 56.7–74.8% and 55.7–73.9%), respectively, by intention-to-treat analysis (P=0.149) and 92.8%, 87.2% and 84.1% (95% confidence interval: 84.4–97.3%, 77.9–93.8% and 73.9–91.2%), respectively, by per protocol analysis (P=0.088). All regimens were well tolerated and compliance was excellent.〈section xml:id="abs1-5"〉〈title type="main"〉Conclusions:Both low-dose clarithromycin triple therapy and tinidazole-containing triple therapy are effective and safe regimens for H. pylori eradication.

Electronic Resource

1043-4666

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Medicine

Electronic Resource