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91.
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93.
Renan Belli Neimar Sartori Lais Dalmagro Peruchi Jackeline Coutinho Guimarães Élito Araújo Sylvio Monteiro Jr. Luiz Narciso Baratieri Ulrich Lohbauer 《Journal of dentistry》2010
Objectives
To evaluate the dentin bond durability of simplified adhesives after one-year (1 y) under water storage and simulated pulpal pressure.Methods
Class I cavities were prepared in sixty human third molars with the pulpal wall located in mid-coronal dentin. The roots were cut off to expose the pulpal chamber, and the teeth were assembled in a pulpal pressure simulator device. A two-step etch-and-rinse adhesive (Single Bond 2/SB), a two-step self-etch adhesive (Clearfil SE Bond/CSE), a three-step self-etch adhesive (Adper Scotchbond SE/SSE) and three all-in-one adhesives (Adper Easy Bond/EB, Clearfil S3 Bond/S3 and Adhese One/AO) were applied according to manufacturer? instructions. No enamel pre-etching was used for the self-etch systems. The cavities were filled with a composite (Z250, 3M ESPE) in four to five horizontal increments and individually cured. Immediately after the final cure, pulpal pressure was set to 15 cm H2O. After 24 h and 1 y under simulate pulpal pressure the teeth were cut following a ‘nontrimming’ microtensile test technique (n = 30) and tested in tension. Kruskall–Wallis and post hoc multiple comparisons were used at α = 0.05. Weibull statistics was applied to SB, CSE and EB. Fractographic analysis of debonded specimens was performed using scanning electron microscopy.Results
At 24 h and 1 y periods, SB showed higher bond strength means than all the others adhesives tested. CSE was not statistically different from EB at 24 h and from EB and SB at 1 y. EB showed bond strength statistically higher than the other three self-etch adhesives, which were not statistically different from each other at 24 h. AO showed significantly lower bond strength than all tested materials after 1 y. For all adhesives the mean bond strength at 1 y were not statistically different from the values measured at 24 h (p > 0.05). Shifts in failure mode patterns and Weibull modulus decrease indicate some degree of bond degradation after the 1 y storage period.Conclusion
One-year of simulated pulpal pressure did not affect dentin bond strength of simplified adhesives in Class I restorations. Signs of degradation were only revealed by fractographic analysis and reliability parameters. 相似文献94.
Albert NM, Gillinov AM, Lytle BW, Feng J, Cwynar R, Blackstone EH. A randomized trial of massage therapy after heart surgery. Heart Lung 2009; 38: 480–90. 相似文献
95.
96.
Computer simulation in conjunction with medical thermography as an adjunct tool for early detection of breast cancer 总被引:1,自引:0,他引:1
Background
Mathematical modelling and analysis is now accepted in the engineering design on par with experimental approaches. Computer simulations enable one to perform several 'what-if' analyses cost effectively. High speed computers and low cost of memory has helped in simulating large-scale models in a relatively shorter time frame. The possibility of extending numerical modelling in the area of breast cancer detection in conjunction with medical thermography is considered in this work.Methods
Thermography enables one to see the temperature pattern and look for abnormality. In a thermogram there is no radiation risk as it only captures the infrared radiation from the skin and is totally painless. But, a thermogram is only a test of physiology, whereas a mammogram is a test of anatomy. It is hoped that a thermogram along with numerical modelling will serve as an adjunct tool. Presently mammogram is the 'gold-standard' in breast cancer detection. But the interpretation of a mammogram is largely dependent on the radiologist. Therefore, a thermogram that looks into the physiological changes in combination with numerical simulation performing 'what-if' analysis could act as an adjunct tool to mammography.Results
The proposed framework suggested that it could reduce the occurrence of false-negative/positive cases.Conclusion
A numerical bioheat model of a female breast is developed and simulated. The results are compared with experimental results. The possibility of this method as an early detection tool is discussed.97.
K. M. Kilbride F. L. Paveglio A. L. AltstattRID=""ID="" <E>Present address:</E> Chiswell Lane Silver Spring MD USA W. G. Henry C. A. JanikRID=""ID="" <E>Present address:</E> Palo Verde Albuquerque NM USA 《Archives of environmental contamination and toxicology》1998,35(2):236-248
Throughout the western United States, studies have identified various detrimental effects of contaminants to aquatic biota
from the use of agricultural drainage water for management of arid wetlands. However, little is known about the relative contributions
of contaminant loading from pollutants dissolved in water compared with those carried by drifting material (e.g., detritus) associated with drainage water. Consequently, we determined loading rates for contaminants dissolved in water and
those incorporated by drifting material for drainage (Diagonal Drain) as well as fresh (S-Line Canal) water used for wetland
management at Stillwater National Wildlife Refuge (SNWR), Nevada during the early, middle, and late periods of the irrigation
season (June through mid-November) in 1993. We found loading rates for trace elements throughout the irrigation season were
almost entirely (> 98%) associated with contaminants dissolved in the water rather than incorporated by drift. Although drift
contributed little to the total loading for trace elements to SNWR wetlands, contaminant concentrations were much greater
in drift compared with those dissolved in water. Loading rates for dissolved As, B, Hg, and total dissolved solids (TDS) differed
among periods for the Diagonal Drain. Along the Diagonal Drain, loading rates for dissolved As, B, Hg, Mo, unionized ammonia
(NH3-N), TDS, and Zn differed among its three sampling sites. B was the only trace element with differences in loading rates for
drift among periods from the Diagonal Drain. In contrast, loading rates for As, B, Cr, Cu, Hg, Se, and Zn in drift differed
among periods for the S-Line Canal. Along Diagonal Drain, loading rates in drift for B (middle and late periods), Cr, Cu,
and Zn differed among sites. Hg (xˉ ≥ 12.0 ng/L) and NH3-N (xˉ ≥ 0.985 mg/L) dissolved in water as well as B (xˉ ≥ 97.4 μg/g DW) and Hg (xˉ ≥ 0.461 μg/g DW) in drift from the Diagonal
Drain and S-Line Canal exceeded screening levels (SLs) for protection of aquatic biota throughout the irrigation season. Dissolved
As (xˉ ≥ 0.0426 mg/L) in water from the Diagonal Drain during all periods exceeded the SL for protection of aquatic biota.
Dissolved B (xˉ = 1.03 mg/L) in water from the Diagonal Drain during the early period exceeded the SL for protection of aquatic
biota.
Received: 18 September 1997/Accepted: 5 February 1998 相似文献
98.
Morizono H; Listrom CD; Rajagopal BS; Aoyagi M; McCann MT; Allewell NM; Tuchman M 《Human molecular genetics》1997,6(6):963-968
Although many mutations in the ornithine transcarbamylase gene have been
correlated with 'late onset' of hyperammonemia in patients, the effects of
these mutations on enzyme function are largely unknown. Three recurrent
mutations (R40H, R277W and R277Q) found in patients with 'late onset'
disease were incorporated into 'mature' human ornithine transcarbamylase
cDNA and overexpressed in Escherichia coli. The three recombinant mutant
enzymes were purified to homogeneity on an affinity column and their
biochemical characteristics were compared to the wild type enzyme. The
R277W and R277Q mutants display markedly reduced affinity for L-ornithine,
loss of substrate inhibition, alkaline shift of pH optimum, and reduced
thermal stability compared to the wild type enzyme. These differences,
particularly the reduced affinity for L-ornithine, are sufficient to
account for their biochemical effects. In contrast, the 'mature' R40H
mutant was biochemically indistinguishable from the wild type enzyme in
vitro.
相似文献
99.
OBJECTIVE: The purpose of this investigation was to evaluate the influence of finishing and polishing procedures on the decision to replace existing amalgam restorations. METHOD AND MATERIALS: Twenty Class I and Class II amalgam restorations, free from obvious defects, were selected in 6 patients. The restorations were photographed before and after being submitted to a standard finishing and polishing procedure. In the first phase, the preoperative slides were examined by 27 clinicians and senior dental students, who were instructed to inspect each restoration and answer a questionnaire indicating if and why the restoration needed to be replaced. Two weeks later, the postoperative slides were presented to the same examiners, who were asked to answer the same questionnaire as before. RESULTS: At the first phase, there were 236 decisions (44%) to replace existing amalgam restorations. Following the finishing and polishing procedures, 114 decisions (21%) were made to replace existing amalgam restorations. This difference was statistically significant. Secondary caries was the most common reason for replacement. CONCLUSION: The finishing and polishing procedure reversed the decision to replace old amalgam restorations. 相似文献
100.
Background: The incidence of pseudoaneurysm has increased due to the large number of vascular procedures performed and the widespread use of anticoagulation therapy during procedures. Non-invasive methods for management of pseudoaneurysms comprise of ultrasound guided compression (USGC), thrombin therapy, arterial embolisation and endovascular stent graft insertion. We discuss our experience in the management of fourteen cases of pseudoaneurysms using non surgical techniques. 相似文献