Two-temperature chemically-non-equilibrium modeling of argon induction plasmas with diatomic gas

A non-equilibrium modeling of argon–oxygen and argon–hydrogen induction thermal plasmas was performed without thermal and chemical equilibrium assumptions. Reaction rates of dissociation and recombination of diatomic gas and ionization were taken into account with two-temperature modeling. A substantial deviation from LTE exists near the torch wall in argon–oxygen induction plasmas under atmospheric pressure, while small deviation in argon–hydrogen plasmas results from the large collision frequency between electrons and hydrogen atoms.     

Radiation-induced bystander effects induce radioadaptive response by low-dose radiation

When normal human fibroblast cells (MRC-5) received a priming irradiation of 3-20 mGy 4 h prior to irradiation with 1000 mGy, the number of DNA double-stranded breaks (DSBs) decreased significantly to 18.2-18.7 per cell compared with 21 per cell when there was no priming irradiation. This result indicates that a priming irradiation of 3-20 mGy induces a radioadaptive response in MRC-5. The authors' previous study had indicated that DSBs induced by ≤ 20 mGy are due to a radiation-induced bystander effect. These findings suggest that radiation-induced bystander effects might contribute to induction of the radioadaptive response. To test this hypothesis, MRC-5 were suspended in lindane, an inhibitor of radiation-induced bystander effects, which was added to the medium for the priming irradiation of 3-20 mGy. Lindane inhibited the protective effect of priming irradiation on DSBs caused by subsequent irradiation with 1000 mGy. Thus, radiation-induced bystander effects may play a role in radioadaptive responses.     

Assimilative and co-metabolic degradation of chloral hydrate by bacteria and their bioremediation potential

Although the bacterial degradation of chloral hydrate (CH) has been recognized for several decades, its degradation pathway by assimilation has not been demonstrated. In this paper, we report the isolation of the LF54 bacterial strain, which utilizes CH as its sole carbon and energy source. LF54 converted CH into trichloroethanol (TCAol), which was dehalogenated to dichloroethanol (DCAol), and CO(2) was detected as the end product. Another strain that we isolated, RS20, co-metabolized CH into TCAol. Our 16S rRNA gene sequencing and taxonomic analyses revealed that the LF54 and RS20 strains belong to the Pseudomonas and Arthrobacter genera, respectively. When the two strains were inoculated into soil microcosms, both degraded 0.3mM CH to undetectable levels (<0.01mM) within 5days. These results suggest that LF54 and RS20 could be used in the bioremediation of CH-contaminated environments.     

The distribution of ND genes in yeast mitochondrial genomes and the mitochondrial DNA structure of Pichia membranaefacens

For long time, it has been believed that the yeast mitochondrial (mt) genome lacks NADH dehydrogenase subunit genes which are designated ND genes. However, our complete mtDNA sequencing of yeast Hansenula wingei led us to the first finding of seven mitochondrial ND genes. We investigated the distribution of ND genes in mtDNAs of other yeasts including Pichia membranaefaciens, Yarrowia lypolitica, Candida maltosa, Saccharomyces kluyveri and Saccharomyces exiguus. By Southern hybridization with probes of H. wingei's ND1, 2 and 5 genes, we detected positive signals on mtDNAs in P. membranaefaciens, Y. lypolitica, and C. maltosa. To confirm this, we cloned and sequenced DNA fragment of ND5 gene in P. membranaefaciens. We have discussed the sequence homology and genome structure.     

Intrahepatic peripheral cholangiocarcinoma: mode of spread and choice of surgical treatment

BACKGROUND: Classification of macroscopic appearance and standard operative procedures for intrahepatic cholangiocarcinoma (ICC) are still controversial. METHODS: The mode of spread of 12 resected ICCs was examined by light microscopy, and the appropriate operative procedures for the various tumours were considered. RESULTS: Macroscopically, nine tumours were classified as mass-forming type and three as periductal infiltrating type. All patients were treated by major hepatectomy; resection of the extrahepatic bile duct was included in two cases of the periductal infiltrating type. Microscopically, invasion into the portal vein, intrahepatic metastasis and perineural or lymphatic vessel invasion occurred in none, one and all of three tumours of the periductal infiltrating type and in eight, six and six of nine tumours of the mass-forming type. CONCLUSION: ICC of the periductal infiltrating type has a tendency to spread along Glisson's sheath via lymphatic vessels. By contrast, ICC of the mass-forming type tends to invade the liver via the portal vein system; such tumours begin to invade Glisson's sheath through the lymphatic vessels when the tumour has increased in size. Therefore, major hepatectomy with combined resection of the extrahepatic bile duct should be performed for all ICCs of the periductal infiltrating type and for those of the mass-forming type with invasion of Glisson's sheath.     

FATIGUE LIMIT OF BLUNT-NOTCHED COMPONENTS

The position and effective resistance of microstructural barriers and their relation to the fatigue strength of blunt-notched specimens are analysed and modelled for three low-carbon steel microstructures. A relationship for the notch size effect on the basis of the experimental evidence that the fatigue limit (both plain and notched) represents the threshold stress for the propagation of the nucleated microstructurally short cracks, was derived. The derived relationship characterizes the fatigue notch sensitivity by means of the parameter k_td defined as the stress concentration introduced by the notch at a distance d from the notch root surface equal to the distance between microstructural barriers, and was experimentally verified for two notch geometries in three microstructures: ferrite, ferrite–bainite and bainite–martensite.     

Characterization of long-periodic layered structures by X-ray diffraction I: A system for small angle and intermediate angle X-ray diffraction using a reflection kratky camera

A high resolution camera has been developed for the small angle X-ray diffraction measurement of long-periodic layered structures such as Langmuir-Blodgett multilayers, superlattices and liquid crystals. A block collimation system known as a Kratky camera is used to produce a very narrow incident beam. The camera is mounted on a computer-controlled goniometer whose sample holder is rotated around a vertical Θ axis by a pulse motor. Measurements can be carried out in a θ-2θ scan, and also in θ or 2θ scans. Processing of the collected data includes smoothing, and correction for absorption, polarization factor and instrumental broadening. The performance of the present system has been demonstrated by observation of diffraction patterns of a Langmuir-Blodgett film of cadmium arachidate and a GaAs/AlAs superlattice.     

Interplay Between Vorticity and Chirality Inside the Vortex Core in Chiral p-Wave Superconductors

The vortex core in chiral p-wave superconductors exhibits various properties owing to the interplay between the vorticity and chirality inside the vortex core. In the chiral p-wave superconductors, the site-selective nuclear spin-lattice relaxation rate T ^–1 ₁ is theoretically studied inside the vortex core within the framework of the quasiclassical theory of superconductivity. T ^–1 ₁ at the vortex center depends on the sense of the chirality relative to the sense of the magnetic field. The effect of a tilt of the magnetic field upon T ^–1 ₁ is investigated. The effect of the anisotropy in the superconducting gap and the Fermi surface is then investigated. The result is expected to be experimentally observed as a sign of the chiral pairing state in a superconducting material Sr₂RuO₄.     

Hyperthermia and hypoxia increase tolerance of retinal ganglion cells to anoxia and excitotoxicity

PURPOSE: Knowledge of the mechanisms by which retinal ganglion cells are damaged may provide information required to develop novel treatments for diseases that cause retinal ganglion cell death. The authors investigated whether the expression of the 72-kDa heat shock protein in cultured rat retinal ganglion cells increases tolerance to hypoxic and excitotoxic injury. METHODS: Hyperthermia (42 degrees C for 1 hour) and sublethal hypoxia (9% O2 for 6 hours) were used to induce synthesis of the 72-kDa heat shock protein in cultured rat retinal ganglion cells and cultured retinal Müller cells. Induction of the 72-kDa heat shock protein was detected with immunocytochemical and immunoblot techniques. Survival of cultured retinal ganglion cells after exposure to anoxia (< 1% O2 for 6 hours) and glutamate (200 microns for 6 hours) was measured and compared to control cultures stressed previously by hyperthermia or sublethal hypoxia. The effect of quercetin, a blocker of heat shock protein synthesis, was evaluated in parallel experiments. RESULTS: Heat shock protein immunoreactivity was expressed in cultured retinal ganglion cells and Müller cells after hyperthermia and sublethal hypoxia. The mean (+/- standard deviation) retinal ganglion cell survival rates after exposure to anoxia (expressed as a percentage of untreated control cultures) in cells pretreated with sublethal hypoxia (83% +/- 17%) and hyperthermia (82% +/- 19%) were significantly greater than for cells that had no pretreatment (50% +/- 18%, P < 0.001). The mean (+/-standard deviation) retinal ganglion cell survival rate after exposure to glutamate in cells pretreated with sublethal hypoxia (82% +/- 19%) and hyperthermia (86% +/- 17%) were significantly greater than for cells that had no pretreatment (56% +/- 17%, P < 0.001). Inhibition of heat shock protein synthesis with quercetin abolished the protective effects of sublethal hypoxia and hyperthermia on cell survival after anoxia and glutamate exposure. CONCLUSIONS: The neuroprotective effect of hyperthermia and sublethal hypoxia suggests that heat shock proteins confer protection against ischemic and excitotoxic retinal ganglion cell death.     

Usefulness and limitations of ultrasonography in the initial evaluation of blunt abdominal trauma

BACKGROUND: In the assessment of blunt abdominal trauma, the reliability of ultrasonography (US) in identifying individual organ injuries remains uncertain, in spite of its usefulness in detecting hemoperitoneum. This study was designed to evaluate the overall diagnostic value of US, including identification of individual organ injuries. METHODS: The accuracy of US in the detection of intra-abdominal injuries and the identification of individual organ injuries was evaluated in 1,239 patients seen during a 15-year period. Accuracy was based on detection of intraperitoneal fluid, free air, or irregular parenchymal lesions. RESULTS: For the detection of injuries, US was 94.6% sensitive, 95.1% specific, and 94.9% accurate. Individual organ injuries were identified with sensitivities of 92.4, 90.0, 92.2, 71.4, and 34.7% for the liver, spleen, kidneys, pancreas, and intestine, respectively. CONCLUSION: US is reliable for the detection of injuries and the identification of solid-organ injuries despite its poor sensitivity for intestinal injuries.