An improved GaAs device model for the simulation of analog integrated circuit

This paper describes an improved device model of GaAs MESFETs and heterojunction FETs for the design and analysis of analog integrated circuits. The proposed device model provides a new expression for the current and the capacitance of the device,which gives excellent agreements with experimental data for all regions of device operation. For the expression of the low frequency anomalies of GaAs devices, an improved technique with an equivalent circuit are presented to model the frequency dispersion of the transconductance and the drain conductance of the device, which give a good agreement with the experimental data of both the frequency dispersion and the lag effect of the device. The new device model proposed here clearly provides a superior prediction of the performance of GaAs analog integrated circuit.     

Immunohistochemical studies in depressed type adenomas of the stomach--comparison with protruded type adenomas and depressed type well differentiated mucosal gastric cancers

In this study, we performed immunohistochemical studies using p53 and Ki-67 immunostaining in 48 depressed type adenomas, and compared with protruded type adenomas (n = 28) and depressed type well differentiated mucosal gastric cancers (mcancer: n = 46). Focal and diffuse p53 staining patterns were not noticed in depressed type adenomas and in protruded type adenomas, but were noticed in mcancers (focal: 4.3%, diffuse: 41.3%). Ki-67 positive cells were noticed in surface epithelium in 24.4% of depressed type adenomas, in 21.4% of protruded type adenomas and in 87.0% of mcancers. Ki-67 positive rate in foveolar epithelium (superior, middle, inferior) were noticed in (31.1%, 12.9%, 6.1%) of depressed type adenomas, in (33.4%, 15.4%, 6.9%) of protruded type adenomas and in (33.4%, 31.4%, 20.4%) of mcancers. These results suggest that from the point of immunohistochemistry, depressed type adenomas were similar to protruded type adenomas, but were different from mcancers.     

Adhesion of leukocytes to endothelial cells in atherosclerosis]

The adherence of blood monocytes to the endothelium, followed by transmigration beneath the endothelium, are initiating events in the formation of foam cells, promoting atherogenesis. We showed that adhesion molecules on leukocytes were up- or down-regulated in atherosclerosis, when binding of monoclonal antibodies was measured by indirect immunofluorescence with flow cytometry. Expression of PE-CAM-1 (CD31) on monocytes and LFA-1 (CD11a) on lymphocytes was increased with age. Expression of PECAM-1 in monocytes was also up-regulated in patients with coronary artery disease. Being unchanged on aging, expression of HAR (CD44) on polymorphonuclear leukocytes and monocytes was increased in patients with coronary artery disease. On the other hand, expression of L-selectin (CD62L) on polymorphonuclear leukocytes, and LFA-1, CR3 (CD11b) and VLA-4 (CD49d) on monocytes was decreased. These findings may show the mechanism of increased chemotaxis of monocytes beneath the endothelium during the incipient stage of atherosclerosis.     

Ultrawide 75-nm 3-dB gain-band optical amplification witherbium-doped fluoride fiber amplifiers and distributed Raman amplifiers

An extremely large 3-dB gain-bandwidth of 75 nm (1531-1606 nm) is achieved with a partially gain-flattened erbium-doped fluoride fiber amplifier and a distributed Raman amplifier. The Raman amplifier consists of a 85-km dispersion-shifted fiber (transmission fiber) and a practical 1505-nm Fabry-Perot laser diode pump. 9×2.5 Gb/s wavelength-division-multiplexing (WDM) transmission is successfully demonstrated using two 75-nm gain-band amplifiers as in-line and preamplifiers     

Spontaneous esophageal rupture after gastrointestinal examination using barium

We experienced a case of spontaneous rupture of the esophagus after gastrointestinal examination using barium. A 48-year-old male experienced severe chest pain after vomiting following gastrointestinal examination. Chest X-ray revealed a right pneumothorax and pleural effusion by barium. We diagnosed spontaneous rupture of the esophagus and performed right thoracotomy 6 hours after onset of symptoms. At 10 cm above the diaphragm, there was a vertical perforation 3 cm in length. Following saline lavage, the ruptured esophageal wall was directly closed by the layer to layer method. The post operative course was uneventful and the patient was discharged 3 weeks after surgery. Cases of spontaneous rupture of the esophagus into the right thoracic cavity induced by gastrointestinal examination are extremely rare.     

Specific and independent recognition of U3 and U5 att sites by human immunodeficiency virus type 1 integrase in vivo

The retroviral attachment (att) sites at viral DNA ends are cis-acting regions essential for proviral integration. To investigate the sequence features of att important for human immunodeficiency virus type 1 (HIV-1) integration in vivo, we generated a series of 25 att mutants of HIV-1 by mutagenesis of the U3, U5, or both boundaries of att. Our results indicated that the terminal 11 or 12 bp of viral DNA are sufficient for specific recognition by HIV-1 integrase (IN) and suggested that IN might recognize each att site independently in vivo.     

Comparison of automatic boundary detection and manual tracing technique in echocardiographic determination of left atrial volume

Previous reports have indicated that echocardiography with automatic boundary detection (ABD) is useful for the noninvasive estimation of left ventricular volume. However, few data exist regarding the measurement of left atrial (LA) volume, which also provides pivotal information in the clinical setting. Therefore, the feasibility of LA volume measurement by ABD in comparison with the manual tracing using modified Simpson's method (SM) was evaluated. Fifty-nine patients with coronary artery-disease with sinus rhythm were examined. Using ABD, a region of interest was set around the LA border and mitral annulus from an apical four-chamber view. The maximal and minimal LA volume (Vmax and Vmin) were measured from the volume waveform. Using the SM, the maximal and minimal LA volume were measured by the manual tracing on frozen frames at the apical four-chamber view. The ABD displayed a curve of LA volume change that consisted of passive emptying, diastasis, and active emptying phases during the left ventricular diastolic period. Under these conditions, the Vmax and Vmin were 43.7 +/- 11.2 ml and 21.1 +/- 7.6 ml, respectively, yielding the volume change of 22.6 +/- 6.0 ml. By the SM, Vmax and Vmin were 43.1 +/- 9.9 ml (r = 0.94, p < 0.0001, y(ABD) = 0.91x (SM) + 3.6) and 22.0 +/- 9.0 ml (r = 0.91, p < 0.0001, y = 0.94x + 0.7), respectively, and the volume change was 22.8 +/- 6.1 ml (r = 0.82, p < 0.0001, y = 0.84x + 3.8). These results indicate that the ABD from the apical four-chamber approach could provide an accurate estimation of LA volume change, suggesting the potential value of this method in assessing LA function, although some technical difficulties need to be further overcome.     

Structural Degradation of Tobermorite during Vibratory Milling

Mechanochemistry of hydrothermally prepared Al-free and Al-substituted 1.1 nm tobermorite was studied using ²⁹Si NMR, XRD, and TGA-DTA. Tobermorite has a double-chain structure and Al/Si substitution occurs preferentially at bridging tetrahedra. By using the vibration mill, both tobermorites were observed to decompose as a function of milling time to form amorphous C-S-H-like phases. The decomposition rate was higher for the Al-substituted tobermorite. The decomposition process occurs mainly at the bridge portion of the silicate double chain. In the Al-substituted tobermorite, the breakage seems to occur preferentially at the points where Al has replaced Si. On heating the amorphous C-S-H-like phase, wollastonite is formed. However, no decrease was observed at the wollastonite formation temperature.