Reliable Test Method Research Articles

Establishment of a Direct PCR Assay for Simultaneous Differential Diagnosis of African Swine Fever and Classical Swine Fever Using Crude Tissue Samples.

African swine fever (ASF) and classical swine fever (CSF) are contagious swine diseases that are clinically indistinguishable from each other; hence, reliable test methods for accurate diagnosis and differentiation are highly demanded. By employing a buffer system suitable for crude extraction of nucleic acids together with an impurity-tolerant enzyme, we established a multiplex assay of real-time reverse-transcription polymerase chain reaction (rRT-PCR) for simultaneous detection of ASF virus (ASFV), CSF virus (CSFV) and swine internal control derived genes in a sample without the need for prior purification of viral nucleic acids. We applied this method to test serum and tissue samples of infected pigs and wild boars and compared the statistical sensitivities and specificities with those of standard molecular diagnostic methods. When a serum was used as a test material, the newly established assay showed 94.4% sensitivity for both and 97.9 and 91.9% specificity for ASFV and CSFV detection, respectively. In contrast, the results were 100% identical with those obtained by the standard methods when a crude tissue homogenate was used as a test material. The present data indicate that this new assay offers a practical, quick, and reliable technique for differential diagnosis of ASF and CSF where geographical occurrences are increasingly overlapping.

Factors affecting employee commitment of office staff in Ho Chi Minh City

This paper examined the factors affecting the commitment of office staff in Ho Chi Minh City (HCMC). The data is collected through questionnaires from 253 office staff; the SPSS software is used to analyse data through Cronbach’s Alpha reliability testing method, Exploratory Factor Analysis (EFA), and regression analysis. The research results revealed that training and development opportunities, salary and bonuses, and employee benefits are three critical factors that positively affect the commitment of office staff to the enterprise. The study provides implications or strategies for managers to improve their human resource management and enhance long-term employee commitment. Besides, the study also provides recommendations for future research.

Effect of Equal Volume Replacement of Fine Aggregate with Fly Ash on Carbonation Resistance of Concrete.

Concrete is prepared by substituting an equal volume of fly ash for fine aggregate, and the effect of substitution rate on its carbonation resistance is studied. Using a rapid carbonation test, the distribution law of the internal pH value of concrete with fly ash as fine aggregate (CFA) along the carbonation depth under different substitution rates (10%, 20%, 30%, and 40%) after carbonation is studied and compared with the test results of phenolphthalein solution. Then, to further clarify the damage mechanism of fly ash replacing fine aggregate on concrete carbonation, the changes in the pore structure and micromorphology of CFA after carbonation are studied by means of mercury intrusion pressure and electron microscope scanning tests. The results indicate that the carbonation depth of CFA increases gradually with increasing carbonation time. In particular, in the later stage of carbonation, the carbonation rate of concrete decreases significantly with an increase in the substitution rate. The carbonation depth XC of CFA measured by phenolphthalein solution is approximately 0.24–0.39 times of the complete noncarbonation depth measured by the pH method. The pH value test is a reliable test method that can reveal the carbonation mechanism of CFA. Carbonation can significantly reduce the proportion of more harmful holes in concrete with a large amount of fly ash, but it can also increase the proportion of less harmful and harmful holes. In general, the pore size distribution and micromorphology of concrete can be improved by replacing fine aggregates with fly ash.

Experimental Evaluation of Shear Properties of Lightweight PVC Core for Marine Application Using Digital Image Correlation System

Sandwich structures are well-known and frequently used solutions in marine applications, especially when structural stiffness is required. An important part of the sandwich structure is the core, which usually carries shear loads. Therefore, choosing a reliable test method and knowing the exact shear properties of the particular core used in the structural design is beneficial for every engineer. Shear properties of the FlexyFoam M-55, a closed-cell, lightweight PVC foam with an apparent density of 60 kg/m3, have been investigated according to the ASTM C273 standard, using the tensile and compressive loading of metal supporting plates glued to the PVC foam sample. A digital image correlation (DIC) technique was used to monitor the crack propagation, and the appearance of secondary stresses at the foam-adhesive interface and strain field for the representative sample was presented. Displacement was measured using the testing machine sensors and compared to the measurements from the DIC technique. Specimen manufacturing details, surface preparation, and the gluing sequence were described, and measuring equipment and experiment settings were presented. Stress-strain curves have been presented and shear modulus and ultimate shear strength of the foam were compared for each test approach. The results were discussed and compared with the manufacturer’s data, as well as with foams of similar densities. The well-established approach in testing the core material was discussed, and recommendations were given to improve the testing procedure.

Identifying SARS-COV-2 infected patients through canine olfactive detection on axillary sweat samples; study of observed sensitivities and specificities within a group of trained dogs.

There is an increasing need for rapid, reliable, non-invasive, and inexpensive mass testing methods as the global COVID-19 pandemic continues. Detection dogs could be a possible solution to identify individuals infected with SARS-CoV-2. Previous studies have shown that dogs can detect SARS-CoV-2 on sweat samples. This study aims to establish the dogs’ sensitivity (true positive rate) which measures the proportion of people with COVID-19 that are correctly identified, and specificity (true negative rate) which measures the proportion of people without COVID-19 that are correctly identified. Seven search and rescue dogs were tested using a total of 218 axillary sweat samples (62 positive and 156 negative) in olfaction cones following a randomised and double-blind protocol. Sensitivity ranged from 87% to 94%, and specificity ranged from 78% to 92%, with four dogs over 90%. These results were used to calculate the positive predictive value and negative predictive value for each dog for different infection probabilities (how likely it is for an individual to be SARS-CoV-2 positive), ranging from 10–50%. These results were compared with a reference diagnostic tool which has 95% specificity and sensitivity. Negative predictive values for six dogs ranged from ≥98% at 10% infection probability to ≥88% at 50% infection probability compared with the reference tool which ranged from 99% to 95%. Positive predictive values ranged from ≥40% at 10% infection probability to ≥80% at 50% infection probability compared with the reference tool which ranged from 68% to 95%. This study confirms previous results, suggesting that dogs could play an important role in mass-testing situations. Future challenges include optimal training methods and standardisation for large numbers of detection dogs and infrastructure supporting their deployment.

Gold Nanoparticles and Plant Pathogens: An Overview and Prospective for Biosensing in Forestry.

Plant diseases and their diagnoses are currently one of the global challenges and cause significant impact to the economy of farmers and industries depending on plant-based products. Plant pathogens such as viruses, bacteria, fungi, and pollution caused by the nanomaterial, as well as other important elements of pollution, are the main reason for the loss of plants in agriculture and in forest ecosystems. Presently, various techniques are used to detect pathogens in trees, which includes DNA-based techniques, as well as other microscopy based identification and detection. However, these methodologies require complex instruments and time. Lately, nanomaterial-based new biosensing systems for early detection of diseases, with specificity and sensitivity, are developed and applied. This review highlights the nanomaterial-based biosensing methods of disease detection. Precise and time effective identification of plant pathogens will help to reduce losses in agriculture and forestry. This review focuses on various plant diseases and the requirements for a reliable, fast, and cost-effective testing method, as well as new biosensing technologies for the detection of diseases of field plants in forests at early stages of their growth.

A practical laboratory method to determine ceftazidime-avibactam-aztreonam synergy in patients with New Delhi metallo-beta-lactamase (NDM)–producing Enterobacterales infection

In response to infection with New Delhi metallo-beta-lactamase (NDM)-producing Enterobacterales, combination antimicrobial therapy with ceftazidime/avibactam (CAZ/AVI) plus aztreonam (ATM) has been explored. This study evaluated a practical laboratory method of testing for clinically significant synergy between CAZ/AVI+ATM in NDM-producing Enterobacterales. Minimum inhibitory concentrations (MICs) of clinical NDM-producing isolates were determined for ATM alone and CAZ/AVI+ATM using broth dilution. Restoration of the ATM breakpoint after the addition of CAZ/AVI was explored. A CAZ/AVI Etest/ATM disc method was compared with broth dilution. Of 43 isolates, 33 (77%) were ATM resistant (median [range] MIC=56 [16-512] mg/L). Addition of CAZ/AVI restored the ATM breakpoint (MIC <4 mg/L) in 29 of 33 resistant isolates (89%). Overall, the Etest/disc method correlated with the findings from broth dilution in 35 of 43 cases (81%). Etest/disc sensitivity was 77% and specificity 85%. Positive predictive value was 92% and negative predictive value 61%. CAZ/AVI+ATM demonstrated significant synergy in most ATM-resistant NDM-producing Enterobacterales. The Etest/disc method is a quick, reproducible, and reliable method of testing for clinically relevant synergy in the microbiology laboratory.

Developing Immunity Testing for SARS-CoV-2 and Other Novel Vaccines—Correlates of Immunogenicity Parameters with Protection

During the assessment and licensing of novel vaccines, as well as post licensure follow up, it is critical to have reliable immunogenicity testing methods that relate well to real life protection [...].

Rapid Detection and Antimicrobial Susceptibility Testing of Pathogens Using AgNPs-Invertase Complexes and the Personal Glucose Meter.

Rapid detection of pathogens and assessment of antimicrobial susceptibility is of great importance for public health, especially in resource-limiting regions. Herein, we developed a rapid, portable, and universal detection method for bacteria using AgNPs-invertase complexes and the personal glucose meter (PGM). In the presence of bacteria, the invertase could be released from AgNPs-invertase complexes where its enzyme activity of invertase was inhibited. Then, the enzyme activity of invertase was restored and could convert sucrose into glucose measured by a commercially PGM. There was a good linear relationship between PGM signal and concentration of E. coli or S. aureus as the bacteria model with high sensitivity. And our proposed biosensor was proved to be a rapid and reliable method for antimicrobial susceptibility testing within 4 h with consistent results of Minimum Inhibitory Concentrations (MICs) testing, providing a portable and convenient method to treat infected patients with correct antibiotics and reduce the production of antibiotic-resistant bacteria, especially for resource-limiting settings.

Non-Destructive Multi-Method Assessment of Steel Fiber Orientation in Concrete

Integration of fiber reinforcement in high-performance cementitious materials has become widely applied in many fields of construction. One of the most investigated advantages of steel fiber reinforced concrete (SFRC) is the deceleration of crack growth and hence its improved sustainability. Additional benefits are associated with its structural properties, as fibers can significantly increase the ductility and the tensile strength of concrete. In some applications it is even possible to entirely replace the conventional reinforcement, leading to significant logistical and environmental benefits. Fiber reinforcement can, however, have critical disadvantages and even hinder the performance of concrete, since it can induce an anisotropic material behavior of the mixture if the fibers are not appropriately oriented. For a safe use of SFRC in the future, reliable non-destructive testing (NDT) methods need to be identified to assess the fibers’ orientation in hardened concrete. In this study, ultrasonic material testing, electrical impedance testing, and X-ray computed tomography have been investigated for this purpose using specially produced samples with biased or random fiber orientations. We demonstrate the capabilities of each of these NDT techniques for fiber orientation measurements and draw conclusions based on these results about the most promising areas for future research and development.

Experimental assessment on the dynamic mechanical response of rocks under cyclic coupled compression-shear loading

Rock engineering structures are quite susceptible to cyclic coupled compression-shear loading. Accurately characterizing the dynamic compression-shear behaviors of rocks is thus crucial for the construction safety and disaster prevention of rock engineering. In this study, a convenient and reliable testing method is proposed to characterize the fatigue mechanical response of rocks under cyclic coupled compression-shear loading: an inclined specimen under cyclic uniaxial loading. With the specimen axis inclining the loading direction, a cyclic shear component is introduced into rocks when subjected to cyclic uniaxial compression. Our method has certain distinct merits in the specimen preparation and experimental operation since no undesired loading devices are required. To demonstrate this method, 21 cyclic loading tests are conducted on inclined sandstone specimens with different tilting angles (i.e., 0°, 3°, 6° and 10°) and under different loading frequencies (i.e., 0.5, 1, 2, and 3 Hz). Based on experimental results, the influence of the tilting angle and loading frequency on the dynamic properties of rocks is revealed and a fatigue life prediction function is proposed. With increasing tilting angle of rock specimens or decreasing loading frequency, rock specimens are featured by an increase of nominal hysteresis energy density, leading to higher damage variable and lower fatigue life. Quite different from the axial splitting failure of right cuboid specimens along the loading direction, all inclined rock specimens (i.e., 3°, 6° and 10°) exhibit a prominent shear-dominated failure accompanied by localized tensile damage, and the shear component becomes more remarkable as the tilting angle increases. In addition, with a higher tilting angle or under lower loading frequency, the cyclically failed specimen is characterized by a higher degree of fragmentation.

Research of social expectations of university students in the dimensions of psychological well-being

The aim of the article is to argue theoretically and empirically study the relationship between social expectations and psychological well-being of university students. Methodological starting points of empirical research are outlined. Valid and reliable test methods are used to study the psychological content parameters of social expectations and psychological well-being. The results determined that the psychological features of social expectations and psychological well-being of student's youth are theoretically substantiated. It was found that the respondents have an average level of parameters of psychological well-being and social expectations, which indicates moderate life satisfaction and the presence of adequate orientation in the socio-psychological reality. The most formed components of psychological well-being are the balance of affect and meaningfulness, which indicates the awareness of their own lives by student’s youth. It is recorded that the respondents have the least formed - self-acceptance, positive attitude and autonomy.

The Separation of Cannabinoids on Sub-2 µm Immobilized Polysaccharide Chiral Stationary Phases.

The increased use and applicability of Cannabis and Cannabis-derived products has skyrocketed over the last 5 years. With more and more governing bodies moving toward medical and recreational legalization, the need for robust and reliable analytical testing methods is also growing. While many stationary phases and methods have been developed for this sort of analysis, chiral stationary phases (CSPs) are unique in this area; not only can they serve their traditional chiral separation role, but they can also be used to perform achiral separations. Given that mixtures of cannabinoids routinely contain enantiomers, diastereomers, and structural isomers, this offers an advantage over the strictly achiral-only analyses. This work presents the separation of a 10-cannabinoid mixture on several polysaccharide-based sub-2 µm CSPs with both normal-phase and reversed-phase ultra-high-performance liquid chromatography (UHPLC) conditions. Along with the separation of the mixture, appropriate single-peak identification was performed to determine the elution order and reported where applicable.

Trends in the epidemiology of dermatophytosis in the Middle East and North Africa region.

Dermatophytosis corresponds to a broad series of infections, mostly superficial, caused by a group of keratinophilic and keratinolytic filamentous fungi called dermatophytes. These mycoses are currently considered to be a major public health concern worldwide, particularly in developing countries such as those in the Middle East and North Africa (MENA) region. Here we compiled and discussed existing epidemiologic data on these infections in the MENA region. Most of the available studies were based on conventional diagnostic strategies and were published before the last taxonomic revision of dermatophytes. This has led to misidentifications, which might have resulted in the underestimation of the real burden of these infections in the MENA countries. Our analysis of the available literature highlights an urgent need for further studies based on reliable diagnostic tools and standard susceptibility testing methods for dermatophytosis, which represents a major challenge for these countries. This is crucial for guiding appropriate interventions and activating antifungal stewardship programs in the future.

ANALISIS GAYA KEPEMIMPINAN DAN MOTIVASI KERJA TERHADAP KINERJA KARYAWAN

This study aims to examine and analyze the effect of leadership style and motivation on employee performance with a population of PT Boga Berkat Prima Jakarta. The data collection technique was carried out using questionnaires and was intended for 50 employees of PT Boga Berkat Prima Jakarta. The data analysis method in this study uses SPSS Statistics version 24.0 by first using the data testing technique method of validity testing and reliability testing for research questionnaires. Classical assumption test and multiple linear regression analysis, to test and prove the research hypothesis used statistical t test. The results of the analysis show that leadership style has a positive effect on employee performance and motivation also has a positive effect on employee performance

Direct and Indirect Genotoxicity of Graphene Family Nanomaterials on DNA-A Review.

Graphene family nanomaterials (GFNs), including graphene, graphene oxide (GO), reduced graphene oxide (rGO), and graphene quantum dots (GQDs), have manifold potential applications, leading to the possibility of their release into environments and the exposure to humans and other organisms. However, the genotoxicity of GFNs on DNA remains largely unknown. In this review, we highlight the interactions between DNA and GFNs and summarize the mechanisms of genotoxicity induced by GFNs. Generally, the genotoxicity can be sub-classified into direct genotoxicity and indirect genotoxicity. The direct genotoxicity (e.g., direct physical nucleus and DNA damage) and indirect genotoxicity mechanisms (e.g., physical destruction, oxidative stress, epigenetic toxicity, and DNA replication) of GFNs were summarized in the manuscript, respectively. Moreover, the influences factors, such as physicochemical properties, exposure dose, and time, on the genotoxicity of GFNs are also briefly discussed. Given the important role of genotoxicity in GFNs exposure risk assessment, future research should be conducted on the following: (1) developing reliable testing methods; (2) elucidating the response mechanisms associated with genotoxicity in depth; and (3) enriching the evaluation database regarding the type of GFNs, applied dosages, and exposure times.

Rapid Identification of Escherichia coli Colistin-Resistant Strains by MALDI-TOF Mass Spectrometry.

Colistin resistance is one of the major threats for global public health, requiring reliable and rapid susceptibility testing methods. The aim of this study was the evaluation of a MALDI-TOF mass spectrometry (MS) peak-based assay to distinguish colistin resistant (colR) from susceptible (colS) Escherichia coli strains. To this end, a classifying algorithm model (CAM) was developed, testing three different algorithms: Genetic Algorithm (GA), Supervised Neural Network (SNN) and Quick Classifier (QC). Among them, the SNN- and GA-based CAMs showed the best performances: recognition capability (RC) of 100% each one, and cross validation (CV) of 97.62% and 100%, respectively. Even if both algorithms shared similar RC and CV values, the SNN-based CAM was the best performing one, correctly identifying 67/71 (94.4%) of the E. coli strains collected: in point of fact, it correctly identified the greatest number of colS strains (42/43; 97.7%), despite its lower ability in identifying the colR strains (15/18; 83.3%). In conclusion, although broth microdilution remains the gold standard method for testing colistin susceptibility, the CAM represents a useful tool to rapidly screen colR and colS strains in clinical practice.

Assessing the impact of curing on chloride penetration resistance of the concrete cover using sorptivity profiling

The chloride penetration resistance of the near-surface concrete cover depth is greatly influenced by the type and extent of curing provided. Very short or ineffective curing regimes result in less cement hydration and a more porous surface due to early evaporation of capillary water. The resultant depth-dependent capillary pore structure results in a depth-dependent resistance to ingress of aggressive fluids, such as chloride solutions. Without reliable performance test methods for pre-qualification and quality assurance, minimum requirements for curing in specifications for concrete structures exposed to chlorides are typically prescriptive. In this paper, a series of modified rate of absorption tests is used to describe and quantify the effect of curing on the chloride penetration resistance of two concretes subjected to four different curing regimes, including accelerated moist curing. The proposed test method can be used to optimize curing for durability performance and allow credit for use of accelerated curing.

Investigation of Fosfomycin Susceptibility in Extended Spectrum Beta-Lactamase Producing Enteric Bacteria by Disk Diffusion, Automated System and Agar Dilütion Kit

Due to the increase of bacteria that develop resistance to classical antibiotics in recent years, fosfomycin has become one of the antibiotics gaining importance again. Fosfomycin exerts its bactericidal effect on many bacteria by binding to a cytoplasmic enzyme, MurA, and inhibiting the enzyme enopurivil transferase, which is involved in peptidoglycan synthesis. Bacteria producing ESBL are common pathogens in nosocomial infections and resistance is frequently encountered in their treatment. Fosfomycin is considered as an alternative drug in these infections. With its reintroduction, it is important to establish reliable and reproducible susceptibility testing methods for fosfomycin. In this study, it was aimed to evaluate the utility of disk diffusion, agar dilution kit and automated MicroScan methods (Beckman Coulter, Brea, CA, ABD) for fosfomycin susceptibility of ESBL-producing enteric bacteria. The study included 120 ESBL positive isolates of enteric bacteria (89 Escherichia coli, 31 Klebsiella pneumoniae) cultivated from the samples sent to the Microbiology Laboratory of the Mersin University Medical Faculty of Medicine Hospital between May 2019 and November 2019. Fosfomycin susceptibilities of the isolates included in the study were tested by disk diffusion, automated MicroScan and the commercial agar dilution kit. In the study, 37 (30.8%) of 120 isolates were determined as resistant to fosfomycin by disk diffusion method and six (5%) of the isolates were found to be resistant to fosfomycin with the MicroScan automatized system. With the agar dilution kit, 11 (9.1%) of 120 isolates were found to be resistant as the minimum inhibitory concentration (MIC) values were > 32 µg/ml. Fosfomycin resistance was significantly higher in K.pneumoniae isolates than E.coli isolates by agar dilution method (p= 0.006). Ertapenem resistance was detected in seven of 120 isolates. All seven isolates that were resistant to ertapenem were susceptible to fosfomycin by agar dilution method. All three isolates, which were found resistant to colistin, were susceptible to fosfomycin by agar dilution method. In the study, the categorical agreement of the disk diffusion and MicroScan methods in E.coli isolates with the agar dilution was high and the error rates were low. For K.pneumoniae, categorical concordance was calculated as 22.5% for disk diffusion test and 74.1% for MicroScan, while major and minor error rates were found to be quite high. As a result; fosfomycin is thought to be an alternative drug option in the treatment of infections caused by especially carbapenem and colistin resistant bacteria, with its high activity on ESBL-producing enteric bacteria. It has been determined that there is a great agreement between the agar dilution, which is the reference method for the determination of fosfomycin resistance for E.coli, and the MicroScan and disk diffusion methods, and that the disk diffusion method which provides ease of use in terms of cost and labor compared to the agar dilution method, can be used as a reliable method. However, it has been demonstrated that the agar dilution method should be used in K.pneumoniae isolates. Nevertheless; It was concluded that if the automatized system is used in laboratories where agar dilution cannot be performed, the results should be interpreted carefully, since the error rates are very high.

PENGARUH KUALITAS PRODUK, CITRA MEREK DAN WORD OF MOUTH TERHADAP MINAT BELI ULANG MELALUI KEPUASAN KONSUMEN PADA MAHASISWA ESA UNGGUL PENGGUNA IPHONE

The purpose of this study was to determine the effect of product quality, brand image and word of mouth on repurchase interest through consumer satisfaction in Esa Unggul Student Iphone users. This type of research is quantitative research with causal associative research. The population in this study were 170 regular and parallel active students at Esa Unggul University, Faculty of Economics, Citra Raya, which were taken using the purposive sampling method. Data testing was carried out using the validity test, reliability test, and path analysis methods. Based on the results of the study, several conclusions can be drawn as follows: 1) Product Quality, Brand Image, Word of Mouth variables have a positive and significant effect on consumer satisfaction in students of the economics faculty of Esa Unggul University; 2) Variables of Product Quality, Brand Image, Word of Mouth, and Consumer Satisfaction have a positive and significant effect on repurchase interest in students of the economics faculty of Esa Unggul University; 3) Product Quality and Brand Image variables have a positive and significant influence on repurchase intention but consumer satisfaction does not mediate; and 4) Word of Mouth variable has a positive and significant effect on repurchase intention by mediating consumer satisfaction.