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Test Parameters (test + parameter)
Selected AbstractsPerformance of two tube coagulase methods for rapid identification of Staphylococcus aureus from blood cultures and their impact on antimicrobial managementCLINICAL MICROBIOLOGY AND INFECTION, Issue 5 2008P. D. J. Sturm Abstract Test parameters and clinical impact of the direct tube coagulase test (DTCT) for rapid identification of Staphylococcus aureus from blood culture were investigated. The sensitivity of the DTCT at 4 h using saline dilution was 96%, compared with 93% using serum separator tubes; specificity was 100% for both methods. Among 32 patients with S. aureus bacteraemia, treatment modifications were based on microbiology results from the primary source of infection in 12 patients, on a Gram's stain from blood culture in seven patients, and on the DTCT in nine patients. The DTCT is a valuable adjunct in the routine microbiology laboratory because of its good performance, technical simplicity and low cost. [source] Variable-Pulse Nd:YAG Laser in the Treatment of Facial TelangiectasiasDERMATOLOGIC SURGERY, Issue 1 2006AVERY A. BEVIN MD BACKGROUND Variable-pulse 1,064 nm wavelength lasers have been used with good effectiveness on leg telangiectasias and reticular veins and have shown promising results on facial telangiectasias as well. OBJECTIVE To investigate the effectiveness of a variable-pulse neodymium:yttrium-aluminum-garnet (Nd:YAG) laser using a small spot size in the treatment of facial telangi-ectasias. METHODS Eight male patients (mean age 75 years) underwent a single treatment session using a variable-pulse 1.5 mm spot size Nd:YAG laser with epidermal cooling. Telangiectasia diameters were 0.3 to 2.0 mm. Test sites were performed using three pulse widths (3, 20, and 60 ms), with fluences varying depending on vessel size and response. Full treatments were per-formed using test parameters giving the best response. Thirteen weeks later, the patients returned for final evaluation and satisfaction rating. RESULTS Fluences ranged from 226 to 425 J/cm2, with smaller vessels requiring larger energies. Pulse duration was equally divided between the 20 and 60 ms settings. The shortest pulse width (3 ms) was inferior in all patients. Longer pulse durations achieved superior vessel elimination with minimal immediate purpura and no postinammatory hyperpigmentation. The average mean vessel clearance was 26 to 50% in half of the patients and 51 to 75% in the other half as evaluated by three unbiased dermatologists with extensive laser experience. CONCLUSION A small,spot size Nd:YAG laser using a pulse width of 20 ms or higher appears to be effective in clearing a significant percentage of facial telangectasias with a single pass. The side effects were minimal. [source] Cyst-based toxicity tests XII,Development of a short chronic sediment toxicity test with the ostracod crustacean Heterocypris incongruens: Selection of test parametersENVIRONMENTAL TOXICOLOGY, Issue 6 2002Belgis Chial Abstract Experiments were carried out with neonates of the freshwater ostracod Heterocypris incongruens hatched from cysts in order to develop a new culture/maintenance-free solid-phase microbiotest for the toxicity assessment of contaminated sediments. Based on preliminary investigations, a number of test parameters were investigated for a short-chronic assay: hatching time, size of the cups of the multiwell test plates, feeding of the test organisms prior to the test, amount of supplemental algal food, volume of sediment, and duration of the test. On the basis of the findings, a test protocol was formulated for a 6-day assay in 12-cup multiwell plates with 10 organisms per cup and 3 replicates. The test organisms were collected 52 h after the start of the incubation of the cysts in standard freshwater at 25°C under continuous illumination after a 4-h prefeeding with 1.3 mg/mL Spirulina. The test biota in the cups were exposed to 300 ,L of test sediment in 2 mL of standard freshwater with 3 × 107 live algal cells (Raphidocelis subcapitata) as food supplement. Calibrated sand was used as a reference sediment. Mortality and growth of the ostracods were determined after 6 days' incubation at 25°C in darkness. The selected test parameters for the new microbiotest were found adequate for toxicity determination of natural sediments compared with the 10-day contact test with the amphipod Hyalella azteca. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 520,527, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10085 [source] Cyst-based toxicity tests XIII,Development of a short chronic sediment toxicity test with the ostracod crustacean Heterocypris incongruens: Methodology and precisionENVIRONMENTAL TOXICOLOGY, Issue 6 2002Belgis Chial Abstract Experiments were carried out with neonates of the freshwater ostracod Heterocypris incongruens to verify and complete previous choices of test parameters for a new culture/maintenance-free solid-phase microbiotest for freshwater sediments. From trials with increasing volumes of reference sediment, it was concluded that 300 ,L was the most appropriate amount of substrate to be put in 12-cup multiwell plates with 2 mL of standard freshwater. Tests in 3,9 replicates eventually showed that six parallels were needed to have good assay precision (repeatability). Application of the final test protocol to oil-contaminated sediments from the St. Lawrence River in Canada revealed that the 6-day chronic ostracod microbiotest had less variation in repeated tests than did the 10-day contact assay with Hyalella azteca and hence can be considered more precise. Based on the 95% confidence intervals for mortality and growth of the ostracods in the controls (reference sediment) of the 56 tests carried out for the Canadian project, a validity threshold of 20% for mortality was eventually selected, in analogy with the acceptability limits applied in many chronic bioassays. A minimum length of 600 ,m in the control sediment after 6 days' exposure was also taken as the threshold for good health of the test organisms and for reliable test conditions. The new microbiotest has been tailored in a handy and user-friendly new toxkit, the Ostracodtoxkit, which is particularly suited for cost-effective routine monitoring. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 528,532, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10086 [source] Fretting fatigue crack nucleation in Ti,6Al,4VFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 3 2003J. M. WALLACE ABSTRACT Fretting fatigue crack nucleation in Ti,6Al,4V when fretted against itself is investigated to determine the influence of contact pressure, stress amplitude, stress ratio, and contact geometry on the degradation process. For the test parameters considered in this investigation, a partial slip condition generally prevails. The resulting fatigue modifying factors are 0.53 or less. Cycles to crack nucleation, frictional force evolution, crack orientations and their relationship to the microstructure are reported. The crack nucleation process volume is of the same order as the microstructural length scales with several non-dominant cracks penetrating 50 ,m or less. The effective coefficient of friction increases during early part of fretting. Observations suggest that cyclic plastic deformation is extensive in the surface layers and that cyclic ratchetting of plastic strain may play a key role in nucleation of the fretting cracks. A Kitagawa,Takahashi diagram is used to relate the depth of fretting damage to the modifying factor on fatigue life. [source] Migraine Headache Recurrence: Relationship to Clinical, Pharmacological, and Pharmacokinetic Properties of TriptansHEADACHE, Issue 4 2003Gilles Géraud MD Background and Objectives.,Triptan use is associated with headache recurrence, and this has been cited as an important reason for patient dissatisfaction with the treatment. The mechanism by which recurrence occurs is not clear, and the incidence of recurrence varies with the triptan used. In order to explore the pharmacological and physiological interaction of triptans and migraine headache recurrence further, some specific clinical, pharmacological, and pharmacokinetic factors that might influence migraine recurrence were evaluated in a review of the major efficacy data for the drugs in the triptan class. These factors were 5-HT1B and 5-HT1D receptor activities, the pharmacokinetic elimination half-life of each triptan, and the clinical efficacy of each compound, determined by the proportion of patients with headache relief and the therapeutic gain over placebo. Methods.,Clinical data were derived from 31 triptan, placebo-controlled, major efficacy studies used in a previous meta-analysis. The mean recurrence rate, mean headache response, and therapeutic gain were calculated using the results from the individual clinical studies. Mean headache response and therapeutic gain were calculated at the time point used to define recurrence in each study. Data for binding affinity and potency were taken from a direct-comparison in vitro pharmacology study, and the elimination half-life quoted in the data sheet for each triptan was used. Rank correlation with recurrence rate was performed for each of the test parameters. Results.,Mean headache recurrence rates ranged from 17% for frovatriptan 2.5 mg to 40% for rizatriptan. Elimination half-life and recurrence were inversely correlated (r = ,1.0, P = .0016). There was also a significant inverse correlation between 5-HT1B receptor potency and recurrence (r = ,0.68, P = .034), but 5-HT1D receptor potency was not correlated with recurrence (r = ,0.20, P = .54). In addition, the binding affinities for the 5-HT1B and 5-HT1D receptors were not correlated to headache recurrence. Importantly, it also was demonstrated that initial clinical efficacy was not correlated to headache recurrence. The correlation coefficient for headache response was 0.18 (P = .53) and for therapeutic gain, ,0.11 (P = .71). Conclusion.,The incidence of migraine headache recurrence varies between drugs in the triptan class. Migraine recurrence does not appear to be related to initial clinical efficacy, but is influenced by the pharmacological and pharmacokinetic properties of the individual triptans. The triptans with longer half-lives and greater 5-HT1B receptor potency had the lowest rates of headache recurrence. [source] Quantification of red blood cell fragmentation by the automated hematology analyzer XE-2100 in patients with living donor liver transplantationINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 5 2005S. BANNO Summary The fragmented red cell (FRC) is a useful index for diagnosing and determining the severity of thrombotic thrombocytopenic purpura (TTP), thrombotic microangiopathy (TMA) and other similar conditions, as it is found in peripheral blood in patients with these diseases. The FRC expression rate has conventionally been determined by manual methods using smear samples. However, it is difficult to attain accurate quantification by such methods as they are time consuming and prone to a great margin of error. With cases of living donor liver transplantation, the current study examined the possibility of using a multi-parameter automated hematology analyzer, the XE-2100 (Sysmex Corporation) for FRC quantification. While there was a notable correlation between the manual and automated measurements, the manual measurement resulted in higher values. This suggested remarkable variations in judgment by individuals. The FRC values had a significant correlation with the reticulocyte count, red blood cell distribution width (RDW), fibrin/fibrinogen degradation products (P-FDP) and lactate dehydrogenase (LDH) among the test parameters, and this finding was consistent with the clinical progression in patients. The automated method can offer precise measurements in a short time without inter-observer differences, meeting the requirement for standardization. The determination of FRC count (%) by the XE-2100 that enables early diagnoses and monitoring of TTP or TMA will be useful in the clinical field. [source] On the peel behavior of polymer coating,steel system: Effect of hygrothermal agingADVANCES IN POLYMER TECHNOLOGY, Issue 3 2010N. Guermazi Abstract This paper describes the development and application of a new peel protocols for the evaluation of adhesion of a flexible-to-rigid assembly. The developed apparatus allows simulating and predicting the delamination of the polymer coating from the steel substrate. The effect of certain test parameters such as a peel angle and peel speed was discussed. The durability of the retained assembly was equally investigated by considering an accelerated hygrothermal aging. The interfacial damages after conditioning and peel tests were characterized. Using two peeling angles of 90° and 180°, no significant difference was observed in terms of peel responses. The interface behavior seems to be not sensitive to the peel angle. However, an increase in the peel rate induces an increase in the peel strength. The characterization of the interface exhibits two mechanisms: The delamination process of the polymer coating is characterized by cohesive and mixed rupture, respectively, at low and high peel rates. Studying the effects of aging and coating defects on the interface behavior displays a continuous loss of adhesion of the polymer coating especially when it presents physical defects. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:185,196, 2010; View this article online at wileyonlinelibrary. DOI 10.1002/adv.20188 [source] Impact of advanced exercise ECG analysis on cost of coronary artery disease managementJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 4 2010Riccardo Bigi PhD Abstract Background, Conventional analysis of exercise electrocardiogram (EX-ECG) has limited accuracy. This study aims to evaluate the potential impact of improving EX-ECG accuracy on costs of diagnosis and number of misdiagnoses of coronary artery disease (CAD). Methods, A decision-tree model was simulated including sequential application of diagnostic procedures for suspected CAD. The model was structured in two main branches (presence or absence of CAD). A probabilistic sensitivity analysis was then performed for several combinations of improvement in test sensitivity and specificity. Results, A clear trend in cost reduction was observed at improving EX-ECG specificity (about 8,8.5 million dollars, corresponding to a 5.6,7.6% reduction according to the prevalence level). Wrong diagnoses counted for 9,13% of test. Improvements in test parameters lead to reductions in wrong diagnoses, especially when increasing specificity (8.8,12.5%). Conclusions, A proper improvement in EX-ECG sensitivity and specificity would have a relevant impact on the costs of CAD management, while reducing the number of misdiagnoses. [source] Modifications to improve the accuracy of a four-ball test apparatusLUBRICATION SCIENCE, Issue 1 2000P. I. Lacey Abstract The four-ball wear test machine is one of the most widely used tribological tools in both research and industry. In general, the test geometry is self-aligning and minimises the opportunity for random variation. Nonetheless, accurate control of the test parameters remains vital to repeatability and reproducibility. The present paper details a number of modifications to a commercially available test apparatus that have been found to improve accuracy. The applied load on some apparatus was found to vary from the correct value, probably due to frictional drag in the loading system. A feedback control loop was designed and fitted to the applied load mechanism, which resulted in significantly improved accuracy. Finally, the apparatus was fully automated, with complete computer control of all test parameters. Under this, following cleaning and assembly of the test specimens, the required test procedure could be selected from a menu of standard methods, and the computer program then adjusted the test parameters according to the method selected, greatly reducing the possibility of operator error. [source] Reliable assessment of high temperature oxidation resistance by the development of a comprehensive code of practice for thermocycling oxidation testing , European COTEST project ,MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 1 2006M. Schütze Abstract The cyclic oxidation test is the most often used tool in industry to characterise the high temperature oxidation/corrosion resistance of technical materials in the laboratory. In the past, however, there has been the problem of a lack of intercomparability of data from different laboratories and sometimes even from different test runs in the same lab since no general guidelines or standards were existing for this type of test. Being aware of this situation the European COTEST research project was started with 23 participants from 11 countries including representatives from industry, universities, private institutes and national research labs. The present paper reports about the outcome of this project after three years. The project consisted of 8 work packages including literature search on the state-of-the-art at the beginning of the work, experimental investigations supported by a statistics approach in order to quantify the impact of the different test parameters on the test results, a validation testing phase and the development of a comprehensive set of guidelines. The latter is available on the internet and serves as a basis for a future ISO standard for this type of test. [source] Piecewise analysis and modeling of circuit pack temperature cycling dataBELL LABS TECHNICAL JOURNAL, Issue 3 2006Toby Joyce Temperature cycling environmental stress testing (EST) of circuit packs is a standard test procedure for the precipitation of latent defects in order to minimize early product lifecycle customer returns. EST is an expensive, energy-intensive bottleneck in the manufacturing process, one that is based on empiricisms that may be out of date. This presents great opportunity for optimization and test cost reduction. This paper describes the characterization of temperature cycling through analysis and modeling of process data in order to optimize the test parameters,ramp rate, temperature extremes, dwell times, and number of cycles. Failure data from circuit packs tested at a Lucent facility is analyzed using a regression technique and graphical inspection. The dwell and ramp periods of the test are considered in a piecewise manner. A cost model is applied based on distributions fitted to the failure data. The analysis yields a methodology for the dynamic, value-based optimization of temperature cycling EST. © 2006 Lucent Technologies Inc. [source] | |||||||||||||