Testing Spot Research Articles

Characterization of the Efflux Capability and Substrate Specificity of Aspergillus fumigatus PDR5-like ABC Transporters Expressed in Saccharomyces cerevisiae.

This research analyzed six Aspergillus fumigatus genes encoding putative efflux proteins for their roles as transporters. TheA. fumigatus genes abcA, abcC, abcF, abcG, abcH, and abcI were cloned into plasmids and overexpressed in a Saccharomyces cerevisiae strain in which the highly active endogenous ABC transporter gene PDR5 was deleted. The activity of each transporter was measured by efflux of rhodamine 6G and accumulation of alanine β-naphthylamide. The transporters AbcA, AbcC, and AbcF had the strongest efflux activities of these compounds. All of the strains with plasmid-expressed transporters had more efflux activity than did the PDR5-deleted background strain. We performed broth microdilution drug susceptibility testing and agar spot assays using an array of compounds and antifungal drugs to determine the transporter specificity and drug susceptibility of the strains. The transporters AbcC and AbcF showed the broadest range of substrate specificity, while AbcG and AbcH had the narrowest range of substrates. Strains expressing the AbcA, AbcC, AbcF, or AbcI transporter were more resistant to fluconazole than was the PDR5-deleted background strain. Strains expressing AbcC and AbcF were additionally more resistant to clotrimazole, itraconazole, ketoconazole, and posaconazole than was the background strain. Finally, we analyzed the expression levels of the genes by reverse transcription-quantitative PCR (RT-qPCR) in triazole-susceptible and -resistant A. fumigatus clinical isolates. All of these transporters are expressed at a measurable level, and transporter expression varied significantly between strains, demonstrating the high degree of phenotypic variation, plasticity, and divergence of which this species is capable.IMPORTANCE One mechanism behind drug resistance is altered export out of the cell. This work is a multifaceted analysis of membrane efflux transporters in the human fungal pathogen A. fumigatus Bioinformatics evidence infers that there is a relatively large number of genes in A. fumigatus that encode ABC efflux transporters. However, very few of these transporters have been directly characterized and analyzed for their potential role in drug resistance.Our objective was to determine if these undercharacterized proteins function as efflux transporters and then to better define whether their efflux substrates include antifungal drugs used to treat fungal infections. We chose six A. fumigatus potential plasma membrane ABC transporter genes for analysis and found that all six genes produced functional transporter proteins. We used two fungal systems to look for correlations between transporter function and drug resistance. These transporters have the potential to produce drug-resistant phenotypes in A. fumigatus Continued characterization of these and other transporters may assist in the development of efflux inhibitor drugs.

Nondestructive Spot Weld Quality Evaluation by Measurement of Structural Vibration Transfer Through Joined Panels

A nondestructive test method using structural vibrations was proposed for spot weld quality evaluations. The wave propagations in multi-spot-welded structures were analyzed using the spectral element method. The resonance frequency showed dependence on the spot stiffness due to the out-of-phase vibration modes locally generated at the testing spot. The experiments to measure the local vibrations were performed. A vehicle specimen made of multi-spot-welded ultra-high-strength steel panels was used for the evaluation. After exciting one side of the spot by an electric shaker, the resulting vibrations were measured on the other side. The transmitted responses by the input vibrations at the testing spot were obtained. The resonance frequencies depended on the wavelength for local vibrations in the specimen. The weld stiffness was predicted using the vibration transfer function. The estimated weld quality was compared to the actual spot diameter. The weld quality had influence on the dynamic properties and resonant modal vibration of the part under tests. To minimize the effect of the geometric and boundary conditions, the local vibrations affected only by the weld quality was used in this study. The proposed method enabled the efficient structural integrity evaluation using the vibration measurements of the welded structure.

NDT of spot welds by imaging analysis of the residual magnetic flux density – Investigation on the influence of electrode indentation on the measurement results

Nondestructive testing (NDT) of spot welds still poses a great challenge for industrial mass production like automotive body manufacturing or rail vehicle constructions. In these production areas, ultrasonic-based NDT methods with pulse-echo technology have become established. Hitherto, these methods require a lot of experience from the staff, which often makes the results subjective. Furthermore, these methods reach their limits when testing spot welds with deep electrode indentations or huge differences between sheet metal thicknesses. Imaging analysis of the residual magnetic flux density shows great potential especially when addressing the restrictions of the ultrasonic-based NDT methods. Typical spot welds show a characteristic electrode indentation. This indentation influences the measureable magnetic flux density, which depends on the distance between the surface of the spot weld and the sensor. This paper will show the influence of electrode indentation on the test result and presents the resulting restrictions for imaging analysis of the residual magnetic flux density when testing spot welds.

Review and drug therapy implications of glucose-6-phosphate dehydrogenase deficiency.

The pathophysiology, diagnosis, and medication-use implications of glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common enzyme deficiency in humans, are reviewed. Originally identified as favism in patients who experienced hemolysis after ingestion of fava beans, G6PD deficiency results from an X-linked chromosomal mutation that leads to reduced activity of the enzyme responsible for the final step of the pentose phosphate pathway, through which reduced nicotinamide adenine dinucleotide phosphate required for protection of cells from oxidative stress is produced. G6PD deficiency affects about 400 million people worldwide. Diagnosis of G6PD can be made through detection of enzymatic activity (by spectrophotometric testing, fluorescence testing, or formazan-based spot testing) or molecular analysis to detect known mutations of the gene encoding G6PD. Most individuals with G6PD deficiency are asymptomatic throughout life. Symptoms of acute hemolysis associated with G6PD deficiency include anemia, fatigue, back or abdominal pain, jaundice, and hemoglobinuria. The most common precipitators of oxidative stress and hemolysis in G6PD deficiency include medication use and infection. G6PD deficiency should be considered in patients who experience acute hemolysis after exposure to known oxidative medications, infection, or ingestion of fava beans. A diagnosis of G6PD deficiency is most often made through enzymatic activity detection, but molecular analysis may be required in females heterozygous for the disorder. When clinically feasible, rasburicase, primaquine, dapsone, pegloticase, and methylene blue should not be used until a G6PD diagnostic test has been performed.

The analysis of methods effectiveness of automated non-destructive testing of products based on Data Mining methods

Purpose of the study: the analysis of the effectiveness of automated nondestructive testing methods within the objectives of data clustering on the use of short-wave electromagnetic radiation in flaw detection. Research methods: Kohonen self-organizing maps (SOM). The relevance of the work is that due to the increased demand for quality and reliability of products are becoming increasingly important physical methods for automated control of metals and products thereof that do not require cutting or fracture specimens of finished productes. The article noted common features of methods of short-wave electromagnetic control of products. The effectiveness of the Data Mining approach to the construction of a hypothesis on the interrelationships of data groups on non-destructive testing of products is substantiated. As an instrument, the method of self-organizing Kohonen maps was chosen. An example of a part of training data and neural network configuration parameters performing the task of visualization and clustering is given. It is concluded about the lead electromagnetic methods of automated control of complex products in production. The resulting distance matrix and the cluster map are shown. An example of applying the results of analysis to the problem of testing spot welded joints is considered. Given the further directions of research is to develop a computer image processing techniques in the framework of automated non-destructive testing systems.

Structural Changes Associated with Delayed Dark Adaptation in Age-Related Macular Degeneration

To examine the relationship between dark adaptation (DA) and optical coherence tomography (OCT)-based macular morphology in age-related macular degeneration (AMD). Prospective, cross-sectional study. Patients with AMD and a comparison group (>50 years) without any vitreoretinal disease. All participants were imaged with spectral-domain OCT and color fundus photographs, and then staged for AMD (Age-related Eye Disease Study system). Both eyes were tested with the AdaptDx (MacuLogix, Middletown, PA) DA extended protocol (20 minutes). A software program was developed to map the DA testing spot (2° circle, 5° superior to the fovea) to the OCT B-scans. Two independent graders evaluated the B-scans within this testing spot, as well as the entire macula, recording the presence of several AMD-associated abnormalities. Multilevel mixed-effects models (accounting for correlated outcomes between 2 eyes) were used for analyses. The primary outcome was rod-intercept time (RIT), defined in minutes, as a continuous variable. For subjects unable to reach RIT within the 20 minutes of testing, the value of 20 was assigned. We included 137 eyes (n= 77 subjects), 72.3% (n= 99 eyes) with AMD and the remainder belonging to the comparison group. Multivariable analysis revealed that even after adjusting for age and AMD stage, the presence of any abnormalities within the DA testing spot (ß= 4.8, P < 0.001), as well as any abnormalities in the macula (ß= 2.4, P= 0.047), were significantly associated with delayed RITs and therefore impaired DA. In eyes with no structural changes within the DA testing spot (n= 76, 55.5%), the presence of any abnormalities in the remaining macula was still associated with delayed RITs (ß= 2.00, P= 0.046). Presence of subretinal drusenoid deposits and ellipsoid zone disruption were a consistent predictor of RIT, whether located within the DA testing spot (P= 0.001 for both) or anywhere in the macula (P < 0.001 for both). Within the testing spot, the presence of classic drusen or serous pigment epithelium detachment was also significantly associated with impairments in DA (P ≤ 0.018). Our results suggest a significant association between macular morphology evaluated by OCT and time to dark-adapt. Subretinal drusenoid deposits and ellipsoid zone changes seem to be strongly associated with impaired dark adaptation.

Erasure temperature measurements of heat assisted magnetic recording media

For heat assisted magnetic recording (HAMR) media development, measurement of erasure temperature (Te) is interesting and important for practical HAMR testing and applications. Here, we present an investigation on Te measurements of L10 ordered FePt granular HAMR media made using a Laser Heating (LH) method on a home-built HAMR write test system versus that from a bulk heating approach. The HAMR write test system provides HAMR writing, micro-MOKE (magneto-optical Kerr effect) signal detection, and MOKE imaging functions at the same testing spot in one single system. Magnetic force microscopy (MFM) and magnetic Kerr microscopy observations of the scanning laser induced degradation/erasure/demagnetization of the pre-recorded magnetic patterns on disk media (over a wide area of a few hundreds of μm2) show that the magnetic (MFM and Kerr signal) amplitude of the pre-recorded magnetic patterns decreases slowly with increasing laser power (Pw) (/temperature rise) for Pw ≲ 66 mW and then drops sharply to nearly zero for Pw ≥ ∼72 mW (the laser power corresponding to complete thermal erasure when the media temperature is ∼Te). It was further found that this trend of magnetic amplitude reduction with increased Pw is similar to that from magnetic amplitude decrease of pre-recorded magnetic patterns with increased bulk heating temperature. The temperature for complete erasure at laser power, Pw = 72 mW for the LH method, corresponds therefore to ∼650 K (≈Te) for the bulk heating methods. Besides fast measurement, LH (as a comparable and viable approach for erasure measurement) is dynamic, localized, and has time scales closer to practical HAMR situation.

Technical knitting and ergonomical design of 3D seamless compression hosiery and pressure performances in vivo and in vitro

The present study was conducted from a new and innovative view to analyze pressure performances of elastic compression hosieries (ECHs) based on a technical knitting and ergonomic design and development methodology. ECHs with pressure classes I and II have been designed and developed. Multiple influencing factors and their dynamic interaction involved in the working mechanisms of ECHs were analyzed and discussed in this study. Yarn properties, material combinations, knitting structural complex, and parameters setting of machinery elements determine the fabric elasticity, stiffness, hosiery configuration, pressure magnitudes and gradient distribution. A good agreement and significant correlation on pressure performances of the developed hosieries are present from positions B1 to D when being tested on the wooden leg model by using Medical stocking tester in vitro and on the studied subjects’ legs in vivo. A reasonable pressure gradient was presented on the leg model (i.e. 70–100 % pressure at B1 and 50–80 % at C compared with the pressure exerted at ankle B), which supported the technical knitting design methodology applied in this study. However, some differences at ankle region B existed between the in vivo and in vitro values due to differences of anatomic structures that existed on the tested ankle areas. The location of testing points and body postures being undertaken by the wearers also significantly influenced the pressure profiles in vivo. More stretch deformations in hosiery fabric are produced, as assessed by static stiffness index evaluation, at the ankle when the body posture changes from standing to supine. The developed ECHs with pressure classes I and II received positive feedback on pressure and comfort perceptions on testing spot. More explorations are needed to elevate the consistency of the in vitro and in vivo pressure values at ankle region and to investigate their long-term pressure performances in practical wear through innovative knitting technical design with considerations of ergonomic factors and conducting larger scale of wear trials in future studies.

Design of Network Power Meter Based on Modbus TCP

To implement fast transmation for a large amount of the electricity parameters and timely measurement, the network power meter is developed based on Modbus TCP. The power meter mainly uses 32bits ARM processor STM32F103RBT6, thighly integrated Delta-Segma ADC CS5451 and Ethernet chip W5100 built-in hardwired TCP/IP stack. According to the meter usage on the testing spot, the measurement precision and communication speed of the network power meter can well meet the power industry requirements.

The Testing Stand Design and Parameter Determination of Pneumatic Seed Metering Device of No-Till Seeder

testing stand that is able to imitate the vibration of seeder field surface stirred up is designed to analyse the effect of vibration on the seed metering function of pneumatic seeder. The signal of vibration data is collected by tape recorder on the testing spot in testing process and then the vibration signal is analysed. A conclusion is reached based on the analysis of testing result that: the trait vibration of seeder is an approximate periodic function, which may be approximately simulated with sine exciting signal; the trait vibration frequency of seeder ranges form 0 to 68 Hz, the maximum acceleration of vibration makes 25m/s2, and the minimum excited vibration thrust of vibration exciter is 500N. A testing stand for seed metering is designed by taking these parameters as the criterion to simulate field surface excited vibration and analyse the seed metering dynamic characteristic of seed metering device.

Slider Optical Constant Distribution, $n$ and $k$ Correlation, and FH Measurement Accuracy

The slider material is a composition of alumina (Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) and titanium carbide (TiC) with a big difference in the optical constants. The random grain size, shape, and composition of TiC make the effective optical constant of slider air bearing surface (ABS) in the size of test spot vary largely. The spot-by-spot scanning of optical constant over slider ABS by ellipsometer indicates that the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> correlate each other linearly. As the commercia flying height (FH) testers use the averaged <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> value to calculate FH, there is a concern of FH testing error if the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> value at the testing spot derivates from the average value. This work discovered that the FH testing error is mainly determined by the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> correlation rather than the absolute value of <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> dispersion. The laser phase detection method improves the repeatability of FH testing significantly, but the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> correlation is the key to estimate the accuracy of FH measurement.

Energy Dispersive X-Ray Fluorescence (EDXRF) Analysis as a Reliable Nondestructive Industrial Tool

For the past several years the Boeing Aerospace Company has been implementing advanced nondestructive chemical analysis methods to improve product reliability and reduce material inspection costs. Previous testing of incoming material for conformance to vendor test reports or of production materials for verification of alloy composition, had consisted of either time-consuming destructive testing or nondestructive chemical spot testing, which often was insensitive to differences between alloys of similar chemical properties. Beginning in 1974, development of EDXRF techniques was initiated to provide a rapid nondestructive analysis capability for both laboratory and factory use. For materials containing elements easily excited by EDXRF methods, costly destructive sampling and testing can be avoided. Generally, chips, wire, barstock, sheet or plate can be analyzed using an annular radioactive source. The uniformity of the X-ray flux diminishes sample geometry and surface roughness effects.

The separation of appeal and brand-name in testing spot advertising.

The separation of appeal and brand-name in testing spot advertising.