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At least 91 records · Page 5Linked to original sources
PubMed2001

Effect of patch type on the cumulative irritation potential of 4 test materials.

BACKGROUND: Many different patch systems are available for predicting contact dermatitis. It is important to determine the ideal patch to meet the objective of the testing method. OBJECTIVE: The 21-day cumulative irritation test is well accepted for predicting irritation after repeated exposures. The patch type must allow separation of materials to predict irritation potential in the marketplace. Three patch systems were compared to determine which best provides this separation and prediction. METHODS: Four test materials were evaluated using 3 patch systems in a 21-day cumulative irritation test. Tested were water, 0.06% sodium lauryl sulfate (SLS), and 2 underarm products (UAP), one having lower and one having higher irritation potential. The patch types were; Webril pad and 8-mm and 12-mm Finn Chambers. RESULTS: Both the 12-mm Finn Chamber and Webril pad showed the ability to differentiate the higher irritating UAP and the 0.06% SLS from the lower irritation UAP product and water. The 8-mm Finn chamber was less discriminating, showing the 0.06% SLS to be the same as water and the lower-irritating UAP. CONCLUSION: The Webril pad and the 12-mm Finn Chamber are better at discriminating irritation potential than is the 8-mm Finn Chamber. The 12-mm Finn Chamber might also allow discrimination with a lower degree of irritation.

Adolescent↗
PubMed1980

Pediatric speech intelligibility test. I. Generation of test materials.

Normal children between 3 and 7 years of age generated word and sentence messages for use in a new speech intelligibility test. Word materials did not differ as a function of chronological age, vocabulary skills, or receptive language ability. Sentence materials, however, did reflect differences in chronological age, vocabulary skills, and receptive language skills. Older children, approximately 5-10 years, responded with complete, adult-like sentences. Younger children, approximately 3-10 years, responded with either a proform substituted for the noun phrase subject of a sentence or by omitting the auxiliary verb "be" in forming the present progressive verb tense of the sentence. To represent the differences in the children's responses, two different types of test sentences were formed. In one construction, the test sentence is composed of (noun phrase/verb-ing/noun phrase), preceded by the carrier phrase "show me", e.g., "Show me a bear brushing his teeth". In the other construction, the test sentence is composed of (noun phrase/auxiliary verb-ing/noun phrase), e.g., "A bear is brushing his teeth". The two different sentence forms are proposed as a means of equating differences in normal language development among children.

Age Factors↗
PubMed1985

Irritant and allergic responses as influenced by triamcinolone in patch test materials.

While the prior application of triamcinolone acetonide to skin does not strongly influence patch test reactions, the presence of triamcinolone in the materials used for patch testing has a profound effect. Both irritant and allergic reactions to thimerosal are consistently negated when triamcinolone acetonide is present in concentrations of 0.1% and 0.025%.

Dermatitis, Contact↗
PubMed2005

Proficiency testing in immunopathology: establishing the homogeneity of test material.

AIMS: To develop a technique for homogeneity testing of serum aliquot samples suitable for use in the Quality Assurance Program in Clinical Immunology (QAP Pty Ltd). METHODS: Albumin was selected as the surrogate protein marker for the product to be tested and the coefficient of dispersion (COD) calculated as the measure of homogeneity. To detect changes in the average level of homogeneity, cumulative sum control (cusum) charts were used. RESULTS: The COD(%) for each triplicate reading of albumin obtained from 34 specimens was normally distributed with a mean of 0.49% and a standard deviation of 0.25%. In industrial quality control schemes the action line is generally set at the upper 99% confidence limits, hence any triplicate sample would be considered to have acceptable homogeneity if the COD was < or = 1.08%. Cusum charts were created to monitor albumin homogeneity over time. CONCLUSIONS: The use of albumin measurement as the surrogate appears statistically suitable for homogeneity testing in QAP programs for immunodiagnostic testing. CUSUM charts are particularly useful to monitor such homogeneity testing.

Albumins↗
PubMed1978

Leukocyte migration agarose test (LMAT) in sarcoidosis using Kveim test material.

The two-stage leukocyte migration agarose test (indirect LMAT), shown to be a sensitive in vitro assay for cell-mediated immunity, was used to study Kveim reactivity in vitro in patients with sarcoidosis. No Kveim-induced inhibition of leukocyte migration in agarose or Kveim-induced lymphocyte transformation in vitro was found in 23 patients with sarcoidosis, suggesting that the Kveim reaction is not an expression of cell-mediated immunity.

Adult↗
PubMed2004

Bidirectional axial transmission can improve accuracy and precision of ultrasonic velocity measurement in cortical bone: a validation on test materials.

The axial transmission technique uses a linear arrangement of ultrasonic emitters and receivers placed on a same side of a cortical bone site in contact with the skin, involving ultrasonic propagation along the axis of bone. The velocity of the waves radiated from bone has been shown to reflect bone status. The thickness and composition of soft tissue may vary along the length of the bone, between different skeletal sites, or between subjects. Hence, accurate estimates of velocity require first to eliminate the effect of the overlying soft tissue that is traversed by the ultrasound wave. To correct for such bias without measuring soft tissue properties, we designed new ultrasonic probes in the 1-2 MHz frequency range. It is based on propagation along the bone surface in two opposite directions from two sources placed on both sides of a unique group of receivers. The aim is to obtain an unbiased estimate of the velocity without any intermediate calculation of soft tissue properties, such as thickness variation or velocity. Validation tests were performed on academic material such as Perspex or aluminum. We found that head wave velocity values could be biased by more than 10% for inclination of a few degrees between the test specimen surface and the probe. On test materials, the compensation procedure implemented in our probe led to a relative precision error on velocity measurement lower than 0.2 to 0.3%. These results suggest that the correction procedure allows measuring in vivo velocities independently of soft tissue properties.

Algorithms↗
PubMed2003

Emission of biocides from treated materials: test procedures for water and air.

Methods for the determination of biocide emissions from treated materials into water and air were developed and tested in order to support a comparative ecological assessment of biocidal products. Leaching tests, experiments with simulated rain, extraction cleaning of carpets and emission chamber tests were performed with a series of treated materials. The experiments focused on the effect of changes in the procedure as well as characteristics of the specimens and demonstrate the suitability of the proposed methods for biocides of different product types. It was demonstrated that emissions of biocides into water can be compared on the basis of leaching tests in which the emission kinetics of the active ingredients are recorded. However, the water volume per surface area and the timetable for water changes have to be defined in such tests. Functions of flux rates related to time can be well described for inorganic compounds, whereas modelling of the data is more complicated for organic substances. Emission chamber tests using 20-litre and 23-litre glass exsiccators, originally developed to study volatile organic compounds, were successfully adapted for the investigation of the emission of biocides from treated materials which are usually semi volatile organic compounds. However test parameters and the method of analysis have to be adapted to the substances to be determined. Generally, it was found that the emission curves for the semi volatile organic compounds investigated differ from those of volatile organic compounds.

Air Pollutants↗
PubMed1990

[Comparative material testing of dental impression and articulation plasters according to German Industrial Standard DIN 13911].

The purpose of the present investigation was a comparison of three special articulation plasters and three impression plasters. As DIN 13911 does not refer to articulation plasters, the inspection as well as the testing of pouring time, setting time, setting expansion and compressive strength using standard and manufacturer's consistence as carried out conforming to the guidelines for impression plasters. None of the tested plasters could meet the requirements of inspection in all points. Considering the physical parameters all plasters are up to standard, while Alpa quickstone and Arti-Plaster exhibited very low expansion and high compressive strength values. Although the compressive strength standard needs redefining, the value of a standardized testing technique for dental plasters is evident.

Calcium Sulfate↗
PubMed1995

Evaluating lyophilized human serum preparations for suitability as proficiency testing materials for high-density lipoprotein cholesterol measurement.

OBJECTIVE: To evaluate the suitability of various commercial preparations for use by the College of American Pathologists as survey materials in assessing high-density lipoprotein cholesterol measurement performance. DESIGN: Lyophilized human serum preparations from six vendors (vendors A through F) were evaluated to determine which material(s) best mimicked the commutability of fresh human serum. Two freshly collected unfrozen pools prepared from donor specimens were analyzed concurrently with the vendor materials to identify sources of variation and possible matrix bias. Each material was evaluated using 5 common precipitation reagents (phosphotungstate-magnesium, phosphotungstic acid, dextran sulfate [50K and 500K], and heparin-manganese). To evaluate how each reagent separates lipoproteins in each material, the lipoprotein separation patterns were profiled using high-pressure liquid chromatography and compared with separation patterns observed for the fresh human serum pools. MAIN OUTCOME MEASURES: Similarities in performance characteristics of vendor material(s) were compared with fresh human serum. RESULTS: Two of the six materials gave separation profiles for the lipoproteins similar to the typical patterns observed for human serum. Material from vendor B showed the best commutability across all of the precipitation reagents and had the best combination of low overall variability (10% for level 1 and 9.4% for level 2) and minimal concentration differences among reagents. CONCLUSIONS: Vendor B was selected by the College of American Pathologists to provide materials for use in assessing performance of lipid and lipoprotein testing in the 1994 Comprehensive Chemistry Surveys. This study demonstrates the great variability that different vendor preparations introduce into the measurement of high-density lipoprotein cholesterol. It also emphasizes the effort required to evaluate the suitability of processed materials for use in proficiency testing.

Analysis of Variance↗
PubMed1994

Four axial structural and material test machine.

Structural tests of complex motion segments, such as those found in numerous joints in the body, require a flexible test bed capable of coordinated multiple axis control and a thorough understanding of the forces and moments. Past experience with such tests on the wrist, elbow, foot and spine joints pointed to the inadequacies of conventional test machines not designed for such purposes. Therefore, a PC-based four-axial benchtop test machine suited for more flexible, sophisticated, biomechanical testing has been developed and built. The test machine consists of a rigid aluminum frame incorporating three translational and one rotational axis driven by micro-stepping motors. The tester is controlled by an industry standard 486 PC including a motor indexer and analog-to-digital (A-D) board. The custom motion control software (not limited to four channels) is designed to accommodate both stepper and servo controllers in displacement or load control modes, or a feedback mode utilizing any number of A-D inputs to control axis velocity. Each axis can act independently, or dependently as a function of another axis. A six-component load cell was also incorporated for force and moment measurement. This new test machine has been found to be quite feasible and easy to operate in the analysis of joint constraint and laxity measurement.

Biomechanical Phenomena↗
PubMed1976

The Edinburgh spleen: source of a validated Kveim-Siltzbach test material.

Although it is true that some Kveim-Siltzbach test suspension may for reasons unknown behave in a totally nonspecific way and so be useless in the confirmation of active sarcoidosis, the experience with the Edinburgh spleen has shown that it is also true that a preparation can be made which acts specifically in the sarcoid context and fulfils all the Siltzbach criteria. The active principle probably resides in the membrane components of sarcoid tissue cells.

Antigens↗
PubMed1989

[Material testing for the use of titanium in bonded prosthodontic restorations].

The effects of chemically etching cast pure titanium to achieve a microretentive surface morphology were studied by SEM. Etching failed to produce an effective improvement of the retentive structures compared to air brushing with Al2 O3 of 50 microns grain size. The bond strength values of the Silicoater-treated retentive surfaces of titanium and Wiron 88 (bonding agent Comspan) determined by shear tests were considerably higher than those of the air-brushed or chemically etched surfaces (bonding agents Comspan, ABC-Zement, Superbond). The clinical use of the Silicoater procedure in bonded restorations seems to provide a suitable retentive mechanism for titanium frameworks.

Acid Etching, Dental↗