865 research outputs found
Possibility of Macroscopic resonant Tunneling near the Superconductor- Insulator Transition in YBaCuO Thin Films
Experimental results of I-V characteristics near the superconductor-insulator
transition observed for disorder-tuned YBaCuO thinfilms are presented. The I-V
characteristics exibit new quasiperiodic structures as a function of the
current. The current interval, the number of the dI/dV peaks, and the magnetic
field dependence of the peaks are consistent with the theoretical predictions
of the resonant tunneling of a phase particle ina tilted-cosine potential for
asingle Josephson junction with small capacitance.Comment: 7 pages, 4 figures, in press (Europhys. Lett.
A New Endoscopic Technique for Examination of Esophageal Stenosis: The Funnel-shaped Transparent Cap Technique
We have devised a funnel-shaped transparent cap for the endoscopic diagnosis and treatment
of stenosis in the digestive tract. This funnel-shaped cap is made of highly transparent
methacrylic resin. A 73-year-old woman with reflux esophagitis (categorized as grade
D by the Los Angeles Classification) visited our hospital with the chief complaint of
dysphagia. She was examined using an endoscope equipped with a transparent vinyl
chloride hood at its tip. Many pieces of food were found to be trapped in the esophagus. These were removed using tripod forceps or aspirated into the hood. The internal diameter
of the stenotic segment was as small as 1 or 2 mm, and it was difficult to advance the
endoscope past the stenosis. The endoscope was withdrawn, and the attached hood was
removed and replaced with a transparent cap. This provided clear visualization of the
mucosal surface of the stenotic segment, which could not be examined using any conventional
device, permitting the stenosis to be relieved
Color Changes in Electronic Endoscopic Images Caused by Image Compression
In recent years, recording of color still images into magneto–optical video disks has been
increasingly used as a method for recording electronic endoscopic images. In this case,
image compression is often used to reduce the volume and cost of recording media and
also to minimize the time required for image recording and playback. With this in mind,
we recorded 8 images into a magneto-optical video disk in 4 image compression modes
(no compression, weak compression, moderate compression, and strong compression)
using the Joint Photographic Image Coding Experts Group (JPEG) system, which is a
widely used and representative method for compressing color still images, in order to
determine the relationship between the degree of image compression and the color
information in electronic endoscopic images. The acquired images were transferred to an
image processor using an offline system. A total of 10 regions of interest (ROls) were
selected, and red (R), green (G), and blue (B) images were obtained using different
compression modes. From histograms generated for these images, mean densities of R,
G, and B in each ROI were measured and analyzed. The results revealed that color
changes were greater for B, which had the lowest density, than for R or G as the degree
of compression was increased
SHG microscopic observations of polar state in Li-doped KTaO3 under electric field
Incipient ferroelectric KTaO3 with off-center Li impurity of the critical
concentration of 2.8 mol% was investigated in order to clarify the dipole glass
state under electric field. Using optical second-harmonic generation (SHG)
microscope, we observed a marked history dependence of SHG intensity through
zero-field cooling (ZFC), zero-field heating (ZFH), field heating after ZFC
(FH/ZFC) and FH after field cooling (FH/FC). These show different paths with
respect to temperature: In the ZFC/ZFH process, weak SHG was observed at low
temperature, while in the FH/ZFC process, relatively high SHG appears in a
limited temperature range below TF depending on the field strength, and in the
FC and FH/FC processes, the SHG exhibits ferroelectric-like temperature
dependence: it appears at the freezing temperature of 50K, increases with
decreasing temperature and has a tendency of saturation. These experimental
results strongly suggest that dipole glass state or polar nano-clusters which
gradually freezes with decreasing temperature is transformed into
semi-macroscopic polar state under the electric field. However at sufficiently
low temperature, the freezing is so strong that the electric field cannot
enlarge the polar clusters. These experimental results show that the polar
nano-cluster model similar to relaxors would be more relevant in KTaO3 doped
with the critical concentration of Li. Further experiments on the anisotropy of
SHG determine that the average symmetry of the field-induced polar phase is
tetragonal 4mm or 4, which is also confirmed by the X-ray diffraction
measurement.Comment: 26 pages, 8 figures, 1 tabl
The shape parameter of liposomes and DNA-lipid complexes determined by viscometry utilizing small sample volumes
A minicapillary viscometer utilizing \u3c0.5 ml of sample at a volume fraction of \u3c0.1% is described. The calculated a/b of DPPC/DPPG multilamellar liposome was 1.14 as prolate ellipsoids and a/b of dioleoylpropyltrimethyl ammonium methylsulfate-DNA complex at a charge ratio of 4:1 (+/-) was 3.7 as prolate ellipsoids or 4.9 as oblate ellipsoids. The deviation of shape from perfect sphere is thus expressed quantitatively in more than two significant figures. In these measurement, the necessary amount of DNA is \u3c0.5 mg
An Inner Centromere Protein that Stimulates the Microtubule Depolymerizing Activity of a KinI Kinesin
AbstractMitosis requires precise control of microtubule dynamics. The KinI kinesin MCAK, a microtubule depolymerase, is critical for this regulation. In a screen to discover previously uncharacterized microtubule-associated proteins, we identified ICIS, a protein that stimulates MCAK activity in vitro. Consistent with this biochemical property, blocking ICIS function in Xenopus extracts with antibodies caused excessive microtubule growth and inhibited spindle formation. Prior to anaphase, ICIS localized in an MCAK-dependent manner to inner centromeres, the chromosomal region located in between sister kinetochores. From Xenopus extracts, ICIS coimmunoprecipitated MCAK and the inner centromere proteins INCENP and Aurora B, which are thought to promote chromosome biorientation. By immunoelectron microscopy, we found that ICIS is present on the surface of inner centromeres, placing it in an ideal location to depolymerize microtubules associated laterally with inner centromeres. At inner centromeres, MCAK-ICIS may destabilize these microtubules and provide a mechanism that prevents kinetochore-microtubule attachment errors
Lung adenocarcinoma with giant cyst formation showing a variety of histologic patterns: a case report
<p>Abstract</p> <p>Introduction</p> <p>Lung cancer with large cyst formation is relatively rare. This is a case report of a patient with lung cystic adenocarcinoma with multiple histologic patterns. This type of lung adenocarcinoma is believed to be the first reported case in English language medical literature.</p> <p>Case presentation</p> <p>A 60-year-old Japanese woman was admitted to hospital complaining of dyspnea and died of respiratory failure. She had been suffering from lung cancer with pleural effusion for five years. Autopsy analysis revealed lung adenocarcinoma with large cyst formation showing a variety of histologic patterns.</p> <p>Conclusions</p> <p>Autopsy analysis of this atypical case of lung cancer may provide insight and lead to a better understanding of the heterogeneity and clonal expansion of lung adenocarcinoma.</p
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