Transesophageal pacing and recording

Identification of P wave is essential for the diagnosis of various arrhythmias. The transesophageal ECG is useful for obtaining the relationship of atrial-ventricular activation when P wave is difficult to recognize on the surface ECG. Transesophageal pacing is also helpful to evaluate the function of the conduction system and to clarify the mechanism of arrhythmias. Thus, transesophageal pacing and recording can be used as beside electrophysiologic studies in patients with sick sinus syndrome, atrial-ventricular block, atrial flutter, and paroxysmal supraventricular tachycardia.     

CuPc/PbZr0.2Ti0.8O3/(La,Ba)MnO3 field effect transistor heterojunction photomemory

We investigated a photoconductor(PC)/ferroelectric oxide(OF)/semiconductor oxide(SO) POS-FET structure photomemory consisting of organic photoconductor CuPc/inorganic ferroelectric PbZr_0.2Ti_0.8O₃ heterojunction gate and a ferromagnetic oxide semiconductor La_0.87Ba_0.13MnO₃ channel. Visible light information detected by photoconductor CuPc can be memorized in ferroelectric PbZr_0.2Ti_0.8O₃, and non-volatile and non-destructive reading out process of light information memorized in this ferroelectric layer were achieved by reading out the resistance modulation of ferromagnetic semiconductor oxide La_0.87Ba_0.13MnO₃ channel under the photoconductor/ferroelectric gate.     

Crystal structure of 3-isopropylmalate dehydrogenase from the moderate facultative thermophile, Bacillus coagulans: two strategies for thermostabilization of protein structures

The crystal structure of 3-isopropylmalate dehydrogenase from the moderate facultative thermophile Bacillus coagulans (BcIPMDH) has been determined by the X-ray method. BcIPMDH is a dimeric enzyme composed of two identical subunits, each of which takes an open alpha/beta structure with 11 alpha-helices and 14 beta-strands. The polypeptide is folded into two domains. The first domain is composed of residues 1-101 and 257-356, and the second domain, of residues 102-256. The latter domains of the two subunits are associated with one another by a dyad axis to make the dimer, locally forming a beta-sheet and a four-helix bundle. As compared with the structure of the enzyme from the extreme thermophile Thermus thermophilus (TtIPMDH), a new short beta-sheet (residues 329-330 and 340-341) absent in TtIPMDH is formed by the insertion of 5 residues in BcIPMDH. In terms of determinants for thermostabilization, both consistent and inconsistent changes were found between the two enzymes. The regions including inconsistent changes are formed by different usages of the determinants for stabilizing the loops at different levels. Those in BcIPMDH contain some structural redundancies in length of amino acid sequence and flexibility of residues, which seem to be unnecessary for the enzymatic reaction. Such redundancies are also found in the primary structure of the enzyme of the mesophile Bacillus subtilis, but these parts are more stabilized in BcIPMDH by hydrogen bonds and salt bridges. On the other hand, TtIPMDH is stabilized by reducing such redundant parts. This contrast suggests that different strategies may be preferred for thermostabilization, depending on temperature.     

Residual oil cracking combined with hydrogen production by steam-iron reaction

A new residual oil upgrading process has been developed. Residual oils were cracked over an iron oxide catalyst with simultaneous generation of hydrogen. The newly-developed iron oxide catalyst containing CaO and Cr₂O₃ was found to be a good catalyst for this process because it exhibited stable activity in the steam-iron reaction in the laboratory experiment and also in a large scale pilot plant. Effects of these foreign oxides on redox cycles were investigated. The catalyst was designed so as to maintain the stoichiometric balance between the reduction of magnetite and the oxidation of wustite by adding CaO and Cr₂O₃.     

Synthesis of polychloroprene–silica composites by sol‐gel method in the presence of modified polychloroprene containing triethoxysilyl group

Triethoxysilyl‐modified polychloroprene (CR) latex was synthesized by the emulsion copolymerization of 2‐(3‐triethoxysilylpropyl)‐1,3‐butadiene with chloroprene. This latex was mixed with unmodified CR latex and tetraethoxysilane to obtain CR–silica composites by sol‐gel reaction in the latex. SEM observation showed that the silica particles in unvulcanized composites have various diameters ranging from 0.1 to 0.6 μ m, and their size became larger with the decrease of the silica content. Vulcanized CR–silica composites showed that the tensile modulus and tear strength improved with an increase of the amount of modified CR. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1545–1552, 2005     

Clinicopathologic features of patients with hepatocellular carcinoma surviving >10 years after hepatic resection

BACKGROUND: This study was performed to clarify the clinicopathologic features of hepatocellular carcinoma (HCC) patients surviving >10 years after hepatic resection. METHODS: Between January 1971 and April 1987, 142 patients underwent hepatic resection. Thirty-nine patients who died of surgical morbidity (surgical mortality rate: 27.5%) were excluded from this study. Among the 103 patients who survived and were observed for >10 years after surgery, 12 patients (11.7%) survived >10 years after hepatectomy. The surviving patients were divided into 2 groups: 10-year survivors (n = 12) and nonsurvivors (n = 91). A comparative study between the two groups was made. RESULTS: Preoperative liver function tests such as the indocyanine green retention test at 15 minutes and albumin levels showed that 10-year survivors had better liver function than nonsurvivors. With regard to virus markers, 5 of 12 patients (41.7%) were positive for hepatitis B surface antigen (HBs-Ag) and the incidence of hepatitis B virus-related HCC was significantly higher than in nonsurvivors (P = 0.020). The results also showed that 4 of 12 long term survivors had hepatitis C virus (HCV) antibody and 1 patient did not have any HCV antibody or HBs-Ag. In two other patients, the HCV antibody was not measured and HBs-Ag was negative. Among four patients with the HCV antibody, the serum HCV RNA concentration, measured by branched DNA probe assay, was <0.5 in 3 patients and 1.72 in 1 patient. Therefore, the HCV RNA concentration tended to be lower in 10-year survivors. Tumor recurrence occurred in 8 of the 10-year survivors. Solitary recurrence was observed in five patients whereas multiple recurrence was observed in three patients. All five patients with solitary recurrence underwent a second resection. CONCLUSIONS: Based on the results of the current study, good liver function, HBs-Ag positivity, and a low concentration of serum HCV RNA in HCV-related HCC should be considered potentially good predictors of a long term survival.     

The flow characteristics of an upward gas‐liquid two‐phase flow in a vertical tube with a wire coil: Part 1. Experimental results of flow pattern,void fraction,and pressure drop

Experiments were carried out to investigate the flow pattern, average void fraction, and pressure drop of an upward air‐water two‐phase flow in vertical tubes of 25‐mm inside diameter with wire coils of varying wire diameter, pitch, and number of coils in cross section. Five kinds of flow patterns—bubble, slug, churn, semiannular, and annular flow—were defined based on the observation of flow behavior in the experiments. At higher water flowrates, the bubble‐to‐slug transition occurred at lower air flowrates in tubes with wire coils than in smooth tubes. The average void fraction was found by using the drift flux model. Further, the experimental results of the friction pressure drop were compared with the Lockhart‐Martinelli correlation. As a result, a correlation with the constant C in Chisholm's equation was obtained as a function of the wire coil pitch‐to‐diameter ratio. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(8): 639–651, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10066     

Peptidergic innervation in human von Ebner''s glands: an immunohistochemical study

Human bites in cases of homicide, sexual assault, and abuse are often distorted due to the elasticity and curvature of the skin. Physical comparison of a bite mark to a suspect's teeth is sometimes difficult. Saliva, which is usually deposited during biting, can be collected and analyzed to identify the perpetrator. Using simulated bite mark situations in two experimental series, three samples of 40 microL of whole saliva were deposited on the skin of 27 cadavers (at 33 sites) and three samples of 100 microL of whole saliva were deposited on the skin of 5 cadavers (at 12 sites). Saliva was collected using the double swab technique at t = 5 min, t = 24 h, and t = 48 h. DNA was extracted using the modified Chelex method and submitted to PCR-based typing at two short tandem repeat loci. Results indicate that the concentration of DNA in saliva recovered from skin varies as a function of time since deposition. There is a significant decrease in concentration in the first 24 h but the concentration remains stable from 24 to 48 h. The success of PCR amplification is independent of the time since deposition or the concentration of DNA in the saliva sample. Contamination from the DNA of the cadaver was not found in any of the cases studied.