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Notes: We have studied the effects of light on high-temperature superconductor microstrip transmission lines under conditions for which a bolometric photoresponse is expected. We illustrate the pitfall of comparing a spatially local property (such as microwave detected photoresponse) and a global property (such as microwave transmission), and then drawing conclusions regarding the bolometric character of the photoresponse. For low microwave powers, the photoresponse, measured as function of the position of the spot illuminated, provides a measurement of the spatial inhomogeneity of the microwave properties of the film. For microwave powers large enough to depress the critical temperature, such measurements provide information about standing waves in the microstrip.

Notes: We report the first radiation effects study on a superconducting ring resonator made from thin-film YBa2Cu3O7−δ. Exposure to 2 MeV protons causes the superconducting transition temperature Tc to decrease predictably with fluence. For temperatures below about 0.9Tc , there is no significant change in the transmission coefficient, the center frequency, or the quality factor Q of the resonator, even for doses in excess of 4×1016 protons/cm2 (∼0.04 displacements per film atom). Similarly, the low-temperature surface resistance Rs of an unpatterned film does not change with irradiation. We show that this insensitivity to radiation is not predicted by standard theory, and that the dominant part of Rs at low temperature is the residual resistance R0. Thus any viable theory describing the origin of R0 must, as a criterion, explain the origin of its insensitivity to large irradiation doses. This criterion is used to evaluate theories ascribing R0 to weak links, flux pinning, impurities, and lattice imperfections.

Notes: Thin films of YBa2Cu3O7−δ were deposited on both sides of (100) LaAlO3 substrates by metalorganic chemical vapor deposition. Using a gold-coated wafer carrier, improvements in both the transition temperature and critical current density of the film exposed to the carrier (first side) were demonstrated. Tc's of 86–88 K and Jc's≥106 A/cm2 at 77 K were achieved. The microwave surface resistance of both sides of double-sided samples measured at 77 K was approximately 8 mΩ at 36 GHz, scaling to less than 700 μΩ at 10 GHz.

Notes: Thin films of YBa2Cu3O7−δ on (100) LaAlO3 and (100) SrTiO3, up to 5000 A(ring) thick, were grown by metalorganic chemical vapor deposition. The as-deposited films were c-axis oriented, and had transition temperatures between 87 and 89 K, transition widths less than or equal to 1 K, and critical current densities of 1–3×106 A/cm2 at 77 K. Microwave surface resistance measurements at 36 GHz on (100) LaAlO3 showed significant improvements over copper metal at 77 K. Films grown on (100) SrTiO3 exhibited slightly better properties than those grown on (100) LaAlO3. Films which were slightly deficient in barium and rich in yttrium consistently demonstrated superior properties.

Notes: Superconducting, silver-doped films of Y1Ba2Cu3O7−δ have been deposited by spray pyrolysis of aqueous nitrate solutions onto MgO substrates. The superconducting transport properties, microstructure, and microwave losses have been characterized for various amounts of AgNO3 added to the spraying solution. These films had resistive transition temperatures between 79 and 85 K with widths from 3 to 7 K. The room-temperature resistivity was a strong function of the silver doping, dropping by a factor of 50 for the heavily doped films. Critical current densities at 4 K were typically several 103 A/cm2 with little correlation to the silver doping. Lattice constants also were not significantly affected by the silver doping level, however, lightly doped films were denser, had the strongest c axis preferred orientation, and a smoother surface. Rf surface resistance was measured at 18 GHz, and for the best films dropped a factor of 10 below copper by 40 K. The London penetration depth was estimated to be approximately 1 μm for the best films.

Notes: This study analyses the infrastructure of the plasma cell population of periodontitis-affected soft tissue close to the advancing front of interdental lesions. Biopsies from 20 patients and 3 control volunteers were examined: 5 with treated adult periodontitis (AP), 5 with untreated AP, 5 with treated juvenile or postjuvenile periodontitis (JP) and 5 with untreated JP. Plasma cell (PC) counts increased significantly (p 〈 0.05) with lesion severity. They were absent from epithelium and sparse in the clinically healthy control specimens. Degenerate PC tended to be more numerous within JP tissue but differences were not significant (p 〉 0.05) when compared to AP. Intact plasma cells were never seen within JP superficial connective tissue. Russell bodies were small and few in number. The presence of degenerated plasma cells indicated normal formation and release of immunoglobulins within the tissues of AP and JP. Increased counts of degenerate PC and tissue destruction in JP suggested a correlation, possibly attributable to anti-collagen antibody secretion.

Notes: Abstract A redox dye, methylene blue, was compared with subgingival root surface debridement and sterile water in the treatment of adult periodontitis. Plaque and gingival indices, bleeding on probing, and microbiological samples were obtained at baseline, and at 1, 4, 8 and 12 weeks following treatment. All subjects had matched pockets in each of the 4 quadrants, of 5 mm or more. One treatment consisted of 0.1% methylene blue gel irrigated professionally at 0, 1 and 4 weeks, and by subjects at days in between up to 4 weeks, at chosen sites within a randomly selected quadrant (split-mouth design). A 2nd treatment was sterile water irrigation as above. A 3rd quadrant received subgingival debridement, and sites in the 4th received methylene blue incorporated into a slow-release device of a biodegradable collagen alginate vicryl composite. All sites showed improvements in clinical and microbiological parameters. However, no statistically significant differences between treatment types were found for clinical measurements. Although plaque index tended to increase after week 1, gingival index was reduced, as was the papilla bleeding index. Probing depth reductions were approximately 1.2 mm for all treatments. Microbiological variables showed an increase in cocci and a decrease in motile organisms for all groups, the latter reaching statistical significance for subgingival debridement. The reductions in spirochaetes were significant for subgingival debridement and methylene blue by slow-release. Culture demonstrated an increase in the aerobe:anaerobe ratio for all groups, which was statistically significant initially (weeks 1 and 4) for subgingival debridement. Methylene blue was also effective statistically in improving this ratio, both by irrigation and slow-release (week 4). Methylene blue also significantly reduced the numbers of black-pigmented anaerobes during the trial period, both by irrigation and slow–release, which sterile water and subgingival debridement failed to do. No serious adverse experiences were seen, however, significantly greater morbidity was associated with subgingival debridement. These results clearly demonstrate that in altering the microflora to one that is more compatible with periodontal health, methylene blue treatment is comparable, or even better, than the currently standard treatment of subgingival debridement, and is better tolerated.

Notes: Abstract Traditionally cervical dentinal sensitivity (CDS) has been evaluated mainly subjectively on the basis of the individual patient's subjective response, e.g., in the form of verbal rating and visual analogue scales and questionnaires. The stimuli used for evaluating this response can be grouped into 4 main categories: mechanical, chemical, electrical and thermal. This review of the literature, however, indicates that there are problems in evaluating patient subjective response to these various test stimuli used in the assessment and treatment of CDS. Opinions also vary as to the reliability of some of these methods of assessment, although recently, efforts have been made to develop controlled reproducible stimuli more suited to the evaluation of CDS. Currently no single method of eliciting and assessing CDS may be considered ideal. Further research is required to evaluate suitable methodology for the quantification of realistic test stimuli under controlled clinical conditions, whereby the subjective response may be objectively measured by the investigator.

Notes: Abstract The present study comprises an investigation of 7 different probe types, representing currently-marketed major designs (WHO-CPITN, Williams, Michigan), as well as available calibration systems (engraved, etched and painted markings). Width of markings, accuracy of calibration from probe tip, and tine diameter at the tip and at specified points along the tine were assessed, using a stereomicroscope at a magnification of × 40. Blind duplicate measurements of these probe tine characteristics were 100% reproducible to within 0.01 mm. There was an overall range in marking width from 0.00–1.13 mm. The best marking, in that it had no appreciable width and the highest accuracy, was the discrete transition between normal and engraved parts of probes with engraved bands. Mean inaccuracies of different probe sets varied from 0.06 to 0.22 mm. Probes from the same batch from the same production line could differ by more than 0.5 mm in calibration. Mean tip diameter ranged from 0.28 to 0.70 mm. It was concluded that probe tine diameter and calibration should be considered in addition to other variables of periodontal probing. Standardisation of tine characteristics and avoidance of the use of different types or batches in a single study should enhance the accuracy and reproducibility of periodontal probe-dependent measurements.