Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ventilatory responses to isocapnic hypoxia and hypercapnia were studied in six dogs each with a tracheostomy, awake and during anaesthesia with halothane, enflurane and isoflurane (1-2.5 MAC). Isocapnic hypoxic ventilatory response (HVR) was expressed as the parameter A, such that the greater the value of A, the greater the hypoxic response. In the anaesthetized dogs HVR (A) was reduced significantly from the awake value of 2010 +/- 172 (mean + SEM) to 630 +/- 173 by 1 MAC halothane, 495 +/- 105 by 1 MAC enflurane and 952 +/- 157 by 1 MAC isoflurane (PL0.05). All three anaesthetic agents produced significant depression of HUR at 1 MAC, but enflurane was more depressant than isoflurane. At 1.5 MAC all three anaesthetics produced equal and significant depression of HVR at equianalgesic concentrations. Further increases in anaesthetic concentration caused no increase in depression. Hypercapnic drive, as measured by the slope of the VE/PACO2 response curve, was reduced significantly from 9.75 litre min-1 kPa-1 +/- 2.4 in awake dogs to 0.83 +/- 0.56 after 1 MAC halothane, 0.68 +/- 0.53 after 1 MAC enflurane and 1.58 +/- 0.75 after 1 MAC isoflurane. In addition, hypercapnia-induced augmentation of the hypoxic drive was abolished by 1 MAC halothane or enflurane and diminished markedly by 1 MAC isoflurane. It may be clinically significant that hypoxia and hypercapnia during anaesthesia with these agents did not produce optimal stimulation of ventilation.
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PMID:Depression of hypoxic ventilatory response by halothane, enflurane and isoflurane in dogs. 92 74

To develop a new ceramic material that can be machined and infiltrated with glass, a porous alumina blank sintered at 1350 degrees C was made of high purity, super fine alpha-alumina and then infiltrated with glass in this study. The density, bending strength and fracture toughness of the partially sintered alumina and alumina-glass composite were determined. The results indicated that the porous alumina density was 2.12 g/cm3, the three point bending strength 102 MPa, the fracture toughness 1.61 MPam1/2; that the alumina-glass composite density was 3.85 g/cm3, the three point bending strength 385 MPa, and the fracture toughness 4.05 MPam1/2. By SEM and EDXA analysis, lanthanum boroslicate glass was completely infiltrated into the 3 mm thick porous alumina blank for 6 h at 1150 degrees C. These suggest that the new developed alumina blank is suited for clinical use.
Hua Xi Yi Ke Da Xue Xue Bao 1998 Dec
PMID:[Research on bending strength and fracture toughness of alumina-glass composite]. 1074 33

This in vitro study evaluated the effect of removing smear layer and applying adhesive on the marginal adaptation of amalgam fillings to cavity walls. Three groups were established, cavities in group 1 were exposed to 10% EDTA (pH7.4) for 1 minute to remove smear layer before amalgam condensation; cavities in group 2 were also subjected to EDTA, then Miradapt adhesive was applied on the walls, finally amalgam condensed into cavities before the adhesive set; cavities in group 3 received no special treatment before amalgam condensation. After thermocycling, all teeth were subjected to SEM and image analyser. Results showed: Space between restorations and tooth structure in group 1 was 6.31 microns, space in group 2 with adhesive was 3.49 microns and micromechanical interlocking was observed while space in control group was 14.22 microns. Difference among the three groups was statistical significant. It was indicated that removing smear layer and using adhesive resin significantly improved the adaptation of amalgam to cavity walls.
Hua Xi Kou Qiang Yi Xue Za Zhi 1997 Nov
PMID:[Influence of smear layer and adhesive resin on the adaptation of amalgam restoration to cavity walls]. 1147 72

The aim of this work was to investigate machinable glass-ceramics used as oral restoration material in K2O-MgO-Al2O3-SiO2-F glass system. By using of DTA, XRD and SEM investigation, the crystalline structure and characteristics were tested. The chemical composition of WCMM machinable glass-ceramics was defined by the following general formula: (K,Na)Mg3-3x Al2x (AlSi3) O10F2(0.5 < or = x < 0.7). The experimental results show that WCMM is an excellent oral restoration materials in the fabrication of crowns, inlayers and veneers.
Hua Xi Kou Qiang Yi Xue Za Zhi 1997 Aug
PMID:[The preliminary study on WCMM machinable glass-ceramics]. 1147 98

In order to investigate the factors which could enhance the integrity of the biological seal between implant and epithelial cells, basement membrane matrigel was coated on the surface of smooth pure titanium. SEM observations showed that the spreading of primary cultured human gingival epithelial cells on Matrigel coated titanium surface was better than that of control groups on the third and the sixth day. This result suggests that the attachment of human gingival epithelial cells to titanium can be enhanced by the basement membrane matrigel.
Hua Xi Kou Qiang Yi Xue Za Zhi 1997 Feb
PMID:[The influence of basement membrane matrix on the attachment of human gingival epithelial cell to titanium: a scanning electron microscopic study]. 1148 46