The combined method: a novel access technique for fetal endoscopic surgery

BACKGROUND/PURPOSE: To develop practical and less invasive techniques for fetal endoscopic surgery, new methods of lifting the uterine wall to allow fetal surgery without maternal laparotomy were developed and assessed. METHODS: Fetal endoscopic surgical procedures, including tracheostomy and umbilical vascular cannulation, were performed using one of the three methods to enter the uterus without maternal laparotomy in pregnant goats (n = 6; 105 to 115 days' gestation): (1) direct uterine lifting with an air-cushion device; (2) indirect uterine lifting, in which the uterine wall was fixed to the maternal abdominal wall using balloon tip ports inserted percutaneously by Seldinger's method, then the maternal abdomen was lifted mechanically; and (3) combined method, in which low pressure CO2 (5 mm Hg for initial inflation and 2 mm Hg for maintenance) was insufflated into the uterus in addition to the indirect uterine lifting cited above. RESULTS: The direct uterine lifting caused massive injury of myometrium and uterine membranes. The creation of intrauterine space and the protection of the membranes were not accomplished effectively by the indirect uterine lifting only. The combined method provided the adequate intrauterine space and excellent endoscopic visibility for completion of the endoscopic procedures with minimal uterine injury. CONCLUSION: The fetal endoscopic surgery may be accomplished simply and safely by the combined method, a novel technique of uterine lifting to allow fetal surgery without maternal laparotomy.     

Critical heat flux on a flat plate heater located at the middle of a duct in forced flow of pressurized He II

Critical heat fluxes (CHFs) were measured for two types of rectangular ducts containing horizontal flat plate heaters. One has the flat plate heater of 6 mm wide and 20 mm long located on the inner lower wall at 50 mm from the inlet. The other duct has two horizontal flat plates of 6 mm wide and 20 mm long on inner upper and lower walls at 50 mm from the inlet. The equation of CHF for the forced convection containing a new nondimensional-parameter m introduced in order to calculate cross-sectionally averaged liquid temperature at the center of the duct was derived based on two fluid model, ordinary convection theorem and experimental results. It was confirmed that this correlation can describe not only the author's data on the duct but also other worker's data for channels with different shapes and sizes.     

Remineralization effects of xylitol on demineralized enamel

We morphologically determined the effects of xylitol on the remineralization of artificially demineralized enamel. The samples were demineralized and then immersed in a remineralizing solution with or without 20% xylitol at 37 degrees C for 2 weeks. Samples were observed using contact microradiography, a multipurpose image processor (MIP) and a high-resolution electron microscope (HRTEM). Contact microradiography indicated that remineralization occurred in the surface and deep layers of samples immersed in a non-xylitol solution. Samples immersed in a xylitol solution demonstrated less mineralization in the outer 10 microm of the outermost surface layers, but more mineralization in the middle and deep layers, than was observed in the non-xylitol samples. The MIP evaluation indicated that remineralization was more prominent in layers at depths of 50-60 microm in the xylitol samples than in the non-xylitol samples. Observation of the xylitol samples by HRTEM revealed crystals of various sizes and irregular shapes with unclear crystal angles in the outermost surface layers. In the middle layers, they had thickened and angles of crystals are clear. These results indicate that xylitol can induce remineralization of deeper layers of demineralized enamel by facilitating Ca2+ movement and accessibility.     

Analysis of secretion and expression of platelet-derived growth factor in cultured endothelial cells from stroke-prone spontaneously hypertensive rat

1. We characterized the endothelial cell-derived growth factors of SHRSP and Wistar Kyoto rats (WKY), respectively and found that platelet-derived growth factor (PDGF)-B chain related growth factor constituted a major portion of the mitogenic activity of the conditioned media of endothelial cells from both animals. There were no remarkable qualitative differences between the endothelial cell-derived growth factors of SHRSP and WKY. 2. Northern analysis revealed that the expression of PDGF-B chain was 2-4-fold enhanced in cultured aortic endothelial cells of SHRSP. This enhanced expression of PDGF-B chain, which may be induced under chronic hypertensive conditions, is suggested to contribute to the increase in endothelial cell-derived growth factors reported in this animal.     

Antiemetic efficacy of granisetron in pediatric cancer treatment--(2). Comparison of granisetron and granisetron plus methylprednisolone as antiemetic prophylaxis

A crossover clinical trial was carried out to compare the effectiveness and safety of granisetron alone (40 micrograms/kg) with that from a combination of granisetron plus methylprednisolone (MPL, 10 mg/kg) for control of emesis and vomiting induced by anticancer drugs in children with cancer. Complete control of emesis and vomiting were achieved in 95% (19/20 cases) of patients receiving the combination compared to 85% (17/20 cases) of patients receiving granisetron alone. There were no clinical toxicities or side effects in either treatment group. These data indicated that the combination of granisetron plus MPL was superior for control of emesis and vomiting in children receiving cytostatic anticancer drugs.     

Expectancy theory prediction of the goal theory postulate, "The harder the goals, the higher the performance."

Goal theory postulates that harder goals lead to higher performance than do easier goals. The present study tested the prediction, based on expectancy valence theory, that this would be true only if the payoff for succeeding at the harder goal is sufficiently greater than the alternatives to compensate for its greater difficulty. 63 undergraduates were each given an easy and a hard task/goal, requiring the comparison of paired sets of 3-digit numbers. Expectancy theory measures for the 2 goals were obtained from Ss. Performance was higher for the hard goal than for the easy goal, supporting the goal theory postulate. Force was also higher for the hard goal than for the easy goal. In addition, force change across the 2 goals was associated with performance change, supporting the conclusion that expectancy valence theory can predict the goal theory postulate. The valence of goal attainment was higher for the hard goal than for the easy goal. Valence change across the 2 goals was associated with performance change to a greater degree than was expectancy change, suggesting that the attained performance difference can be attributed to the valence difference. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Release behavior of tritium from graphite heavily irradiated by neutrons

The release behavior of tritium formed in graphite has been investigated as a function of radiation damage by means of isochronal annealing of samples heavily irradiated by neutrons. The lithium impurities in graphite were estimated as the source of tritium formation. The main chemical form of released tritium was hydrogen accompanied by a small quantity of methane. No other hydrocarbons could be detected. Tritiated water was always measured, but the formation mechanism was experimentally confirmed as the secondary oxidation of released HT molecule. The release spectrum of tritium in isochronal annealing was shifted to a higher heating temperature with the increase of the neutron fluence received by the graphite crystal. A relationship was established between the amount of tritium released up to a certain temperature and the degree of graphitization of the sample.     

Heat capacities and thermal conductivities of AmO2 and AmO1.5

The thermal diffusivity of AmO₂ was measured from 473 to 773 K and that of AmO_1.5 between 473 and 1373 K using a laser flash method. The enthalpy increment of AmO₂ was measured from 335 to 1081 K and that of AmO_1.5 between 335 and 1086 K using drop calorimetry. The heat capacities of AmO₂ and AmO_1.5 were derived from the enthalpy increment measurements. The thermal conductivity was determined from the measured thermal diffusivity, heat capacity and bulk density. The heat capacities of AmO₂ was found larger than that of AmO_1.5. The thermal conductivities of AmO₂ and AmO_1.5 were found to decrease with increasing temperature in the investigated temperature range. The thermal conductivity of AmO_1.5 with A-type hexagonal structure was smaller than that of AmO₂ with C-type fluorite structure but larger than that of sub-stoichiometric AmO_1.73.     

Pressure dependence of upper critical solution temperatures in the polystyrene - cyclohexane system

The pressure dependence of the upper critical solution temperature $\text{(}\text{d}\text{T}\text{d}\text{p}\text{)}{}_{\mathrm{c}}$ in the polystyrene-cyclohexane system has been measured over the pressure range of 1 to 50 atm. The value of $\text{(}\text{d}\text{T}\text{d}\text{p}\text{)}{}_{\mathrm{c}}$ determined over the molecular weight (M_w) range of 3.7 × 10⁴ to ～145 × 10⁴ greatly depends on the molecular weight of polystyrene. The value of $\text{(}\text{d}\text{T}\text{d}\text{p}\text{)}{}_{\mathrm{c}}$ for a polystyrene solution of low molecular weight (M_w = 3.7 × 10⁴) is positive (3.14 × 10^?3 degree atm^?1), while the values are negative (?0.52 × 10^?3～?5.64 × 10^?3 degree atm^?) for solutions of polystyrene over the high molecular weight range of 11 × 10⁴ to ～145 × 10⁴. The Patterson-Delmas theory of the corresponding state and the newer Flory theory have been used to explain this behaviour.