276 research outputs found
An ytterbium quantum gas microscope with narrow-line laser cooling
We demonstrate site-resolved imaging of individual bosonic
atoms in a Hubbard-regime two-dimensional optical lattice
with a short lattice constant of 266 nm. To suppress the heating by probe light
with the - transition of the wavelength = 399 nm for
high-resolution imaging and preserve atoms at the same lattice sites during the
fluorescence imaging, we simultaneously cool atoms by additionally applying
narrow-line optical molasses with the - transition of the
wavelength = 556 nm. We achieve a low temperature of $T = 7.4(1.3)\
\mu\mathrm{K}$, corresponding to a mean oscillation quantum number along the
horizontal axes of 0.22(4) during imaging process. We detect on average 200
fluorescence photons from a single atom within 400 ms exposure time, and
estimate the detection fidelity of 87(2)%. The realization of a quantum gas
microscope with enough fidelity for Yb atoms in a Hubbard-regime optical
lattice opens up the possibilities for studying various kinds of quantum
many-body systems such as Bose and Fermi gases, and their mixtures, and also
long-range-interacting systems such as Rydberg states.Comment: 14 pages, 6 figure
Resonant Control of Interaction Between Different Electronic States
We observe a magnetic Feshbach resonance in a collision between the ground
and metastable states of two-electron atoms of ytterbium (Yb). We measure the
on-site interaction of doubly-occupied sites of an atomic Mott insulator state
in a three-dimensional optical lattice as a collisional frequency shift in a
high-resolution laser spectroscopy. The observed spectra are well fitted by a
simple theoretical formula, in which two particles with an s-wave contact
interaction are confined in a harmonic trap. This analysis reveals a wide
variation of the interaction with a resonance behavior around a magnetic field
of about 1.1 Gauss for the energetically lowest magnetic sublevel of
Yb, as well as around 360 mG for the energetically highest magnetic
sublevel of Yb. The observed Feshbach resonance can only be induced
by an anisotropic inter-atomic interaction. This novel scheme will open the
door to a variety of study using two-electron atoms with tunable interaction.Comment: 5 pages, 5 figure
Swap-Rate of Entrance Examination and Its Software -SRAS-
When we select N₀ student from N applicants using a result of an entrance examination, which consists of two step selection, the primary test and the secondary test. It is important to evaluate the contribution for each test. Swap-rate is one of the measure of the contribution for each stage test, and it its widely used. In this paper, we describe a population swap-rate and a sample swap-rate in the first. Next, we consider the distribution of applicants who change the result of the test from pass to fail. Finary, we introduce our system "SRAS - Swap-Rate Analysis System-", that can analyze the examination data on such point of view
Immune Reactions Against Elongation Factor 2 Kinase: Specific Pathogenesis of Gastric Ulcer from Helicobacter pylori Infection
Helicobacter pylori (H. pylori) infection is a definite causative factor for gastric ulcers (GUs). In the present study we detected a specific antigen of gastric epithelial cells (HGC-27) using cell ELISA, which was recognized by the sera of GU patients (n = 20) but not in patients with chronic gastritis (CG; n = 20) or in healthy volunteers (HC; n = 10). This antigen was over-expressed by a stressful (heat-stressed) environment, and was identified as elongation factor 2 kinase (EF-2K) by western blotting. The GU patients' lymphocytes stimulated by H. pylori specifically disrupted heat-stressed HGC-27 cells in a cytotoxic assay. In flow cytometry, the effector cells (lymphocytes) from GU patients were significantly differentiated to T helper type 1 lymphocyte (Th1) and cytotoxic T lymphocyte (CTL) as opposed to those from CG patients. The target cells (HGC-27) expressed EF-2K and MHC-class I together with costimulatory molecules from heat stress. This antigen specific immune mechanism could have a prominent role in the pathogenesis of GU
Clinical significance of spa therapy in the treatment of patients with chronic obstructive pulmonary disease (COPD). A study on 520 patients with COPD admitted for last5 years.
1992年1月より1996年12月までの5力年間に当院へ入院した慢性閉塞性呼吸器疾患520例を対象に,疾患の種類,年齢,地域分布などについて検討を加えた。1.最近5年間に当院へ入院した呼吸器疾患患者は588例で,このうち,慢性閉塞性呼吸器疾患患者は520例(88.4%)であった。これらの慢性閉塞性呼吸器疾患のなかでは,気管支喘息が433例(83.3%)と最も多く,その他,慢性気管支炎19例,閉塞性細気管支炎33例,肺気腫35例であった。2.慢性閉塞性呼吸器疾患の年齢別検討では,鳥取県内および遠隔地(鳥取県外)いずれの症例においても,60-69才および70才以上の症例が多い傾向が見られた。3.入院患者の地域分布では,鳥取県内からの入院患者に比べ,遠隔地(鳥取県外)からの入院患者がより多く,その分布別検討では,岡山県,兵庫県,大阪腐,広島県,山口県,愛媛県からの入院患者が多い傾向が見られた。The kind of respiratory diseases, age, and areas where patients came from were discussed in 520 patients with chronic obstructive pulmonary diseas (COPD) admitted at
Misasa Medical Branch for last 5 years from 1992 to 1995.
1. For the last 5 years 588 patients with respiratory diseases were admitted at Misasa Medical Branch. Of these patients, 520 were those with chronic obstructive pulmonary
disease (COPD). Of the 520, 433 (83.3%) were patients with asthma" 19 with chronic bronchitis, 33 with obstructive bronchiolitis, and 35 with pulmonary emphysema. 2. Regarding the distribution of age of these patients, patients between the ages of 60 and 69, and those over the age of 70 were more frequently observed, regardless of the area where patients came from (inside or outside Tottori prefecture). 3. The number of patients from distant areas (outside Tottori prefecture) was larger than the number of
those inside Tottori prefecture. The number of patients from Okayama, Hyogo, Hiroshima, Osaka, Yamaguchi, and Ehime
prefectures was predominantly larger than the number from other distant areas
The Genetic Diversity of Helicobacter pylori Virulence Genes Is Not Associated with Gastric Atrophy Progression
Atrophy of the gastric mucosa is a precursor of intestinal-type gastric cancer, and Helicobacter pylori infection causes atrophic gastritis. The aim of this study was to determine whether the genetic diversity of H. pylori virulence genes is associated with the development and progression of gastric atrophy in humans. We isolated and cultured H. pylori strains from patients with gastric ulcer and duodenal ulcer accompanied by atrophic gastritis in background mucosa. H. pylori strains were stored at -80℃ prior to the experiments being carried out. We analyzed iceA, babA, vacA, cagA, and cagE genes by PCR. The cagA gene was analyzed through sequencing of the C-terminal region containing the EPIYA motif, which is related to tyrosine phosphorylation. Severe atrophy was observed in patients with gastric ulcer. The major phenotype of the vacA gene was s1c/m1 (93オ). The cagA gene was detected in all strains. The cagE gene was not detected in 2 and 5 strains from the mild cases and severe cases, respectively. The major cagA EPIYA motif, which is amino acids repeat in the C terminus, was the A-B-D type (44 of 58 strains). The virulence genes were not statistically associated with the severity of atrophy in the background gastric mucosa in humans. Not only identification of bacterial virulence factors but also studies of the host response will be necessary to investigate the progression of gastric atrophy and subsequent cancer development in humans
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