A comparison of the nasal mask and the nasopharyngeal airway in paediatric chair dental anaesthesia

This study compared the quality of anaesthesia and surgical access afforded by two techniques for the administration of anaesthesia during paediatric chair dental procedures. A total of 50 ASA 1 paediatric day case patients were randomly assigned to receive anaesthesia through either the traditional Goldman nasal mask or through a nasopharyngeal airway. Patients in the nasal mask group were judged to have significantly worse airway patency (p = 0.0001) and significantly more episodes of airway obstruction (14 vs. 4; p = 0.0032) than those in the nasopharyngeal airway group. Anaesthetic, surgical and oxygen saturation data did not differ significantly between the two groups. Operating conditions were universally graded as excellent in the nasopharyngeal airway group, while those in the nasal mask group were graded as excellent/good in only 79% of cases (p < 0.0001). These results suggest that better quality anaesthesia and operating conditions can be achieved by using a nasopharyngeal airway rather than the traditional nasal mask for the administration of anaesthesia to paediatric chair dental patients.     

Bcl-2-independent Bcr-Abl-mediated resistance to apoptosis: protection is correlated with up regulation of Bcl-xL

Bcr - Abl is the molecule responsible for both the transformation phenotype and the resistance to chemotherapeutic drugs found in chronic myelogenous leukemia (CML) cells. Wild-type HL-60, a transformed pro-myelocytic cell line, is very susceptible to apoptosis-inducing agents. We show here that expression of Bcr - Abl in HL-60 cells rendered them extremely resistant to apoptosis induced by a wide variety of agents. The anti-apoptotic effect of Bcr - Abl was found to be independent of the phase of the cell cycle. Treatment with antisense oligonucleotides directed to bcr decreased the expression of the ectopic bcr - abl and restored susceptibility to apoptosis. Double mutations affecting the autophosphorylation site and the phosphotyrosine-binding motif (FLVRES) have been previously shown to impair the transforming activity of Bcr - Abl in fibroblasts and hematopoietic cells, however HL-60 cells expressing this double mutant molecule exhibited the same level of resistance to apoptosis as those expressing the wild-type Bcr - Abl. Interestingly, wild type and mutant Bcr - Abl induced in HL-60 cells a dramatic down regulation of Bcl-2 and increased the levels of Bcl-xL. The level of Bax did not change in response to the presence of Bcr - Abl. Antisense oligonucleotides targeted to bcl-x downregulated the expression of Bcl-x, and increased the susceptibility of HL-60. Bcr - Abl cells to staurosporine. Importantly, HL-60 cells overexpressing Bcl-xL showed higher expression of Bcl-xL but lower resistance to apoptosis when compared to HL-60. Bcr - Abl cells. The results described here show that Bcr - Abl is a powerful mammalian anti-apoptotic molecule and can act independently of Bcl-2. Bcl-xL, however, seems to participate in part in Bcr - Abl-mediated resistance to apoptosis in HL-60 cells.     

Investigation of acoustic waves in thin plates of lithium niobate and lithium tantalate

The general properties of fundamental antisymmetric A0, symmetric S0, and shear horizontal SH0 acoustic waves propagating in thin piezoelectric plates have been theoretically investigated on samples of lithium niobate (LiNbO3) and lithium tantalate (LiTaO3). The results obtained will be useful for a proper development of various physical, chemical, and biological sensors and devices for signal processing based on plate acoustic waves.     

High-temperature zirconium-dioxide binders for the masonry of the outer trap of a reactor

Investigations were performed for the purpose of selecting the compositions of zirconium dioxide binding materials (mortars) with two types of binders: barium monoaluminate and zirconium dioxide binding suspension. The foundations of a technology for obtaining these materials and their applications were developed and the density, porosity, contraction, and behavior in contact with steel and iron oxide melts were described. The mortars developed were recommended for use in a refractory shielding of the outer trap based on zirconium dioxide heat-resisting materials, 2 figures, 1 table, 7 references. Translated from Atomnaya énergiya, Vol. 88, No. 4, pp. 277–282, April, 2000.     

Splitting of pipe steel produced by TMCP

The texture of low-carbon low-alloy pipe steel sheet with bainitic structure produced by thermomechanical controlled processing (TMCP) is studied by means of electron backscatter diffraction (EBSD). Samples generally characterized by splitting (secondary cracks) on fracture in mechanical tests are compared with those that are free of splitting. Splitting occurs in the presence of regions that consist of small crystallites with uniform (001)[110] orientation; those regions extend in the direction of controlled hot rolling. The formation of such regions is thought to be due to γ → α shear transformations with different treatment parameters.