Laboratory Verification Research Articles

Validation of Agitated Patient Remote Monitoring Alarm System in the Intensive Care Unit.

The purpose of this research is to innovate and develop a vision-based remote monitoring alarm system for agitated patients to provide intensive care unit (ICU) nurses with action warnings for agitated patients during their busy work. After the system is completed, preliminary laboratory verification is carried out, and the results are 94.87% in sensitivity, 97.44% in specificity, and 96.15% in accuracy, which enhances the confidence of the follow-up system in clinical testing.

640. Development of a Laboratory Verification Protocol for Concurrent Detection of Bacterial, Fungal, and Antimicrobial Resistance Genes in a Multiplex Syndromic Joint Infection Panel

Abstract Background Verification is a critical component of implementing a diagnostic test in a clinical lab and can be time consuming and costly. A verification protocol and organism panel were developed in collaboration with ZeptoMetrix®, LLC to verify all analyte detections for the BioFire® Joint Infection (JI) Panel*. The BioFire JI Panel detects 31 pathogens and 8 antimicrobial resistance (AMR) genes associated with joint infections from synovial fluid specimens. Methods A protocol was developed using prototype NATtrol™ controls from ZeptoMetrix®, synovial fluid, and the BioFire® FilmArray® 2.0 and the BioFire® FilmArray® Torch Systems. Control materials were tested in the presence of synovial fluid from pooled human donors. The 32 targets required for all analyte detections were divided into 5 pools of 6-7 analytes and then tested over multiple days on several systems. Results Preliminary outcomes were good with a cumulative positive detection rate of 100% (310/310) and expected negative detections of 99.3% (1182/1190) from 50 prototype BioFire JI Panel test runs. AMRs were correctly identified in 50/50 (100%) replicates when a correlated bacterium was present. Unexpected detections of Streptococcus spp. (7/50) and Staphylococcus lugdunensis (1/50) were likely due to contaminants in the synovial fluid; Streptococcus spp. was confirmed by testing the synovial fluid in isolation. Conclusion Efficient performance verification may be achieved by combining 32 organisms/8 AMR into 5 pools and can be completed with 20 test runs in 4 days. The pooling scheme provides multiple positive/negative detections per analyte and accurately detects AMR. The protocol and controls serve as a useful tool for providing reliable detections of targets over multiple days, operators and systems and offers a flexible solution for supporting verification needs. *The BioFire® Joint Infection Panel is currently pending US FDA De Novo review. This product has not been evaluated by other global regulatory agencies for in vitro diagnostic use. Not available for sale. Panel menu subject to change. Disclosures Monica Cronin, MS, BioFire Diagnostics, LLC (Employee) Taylor K. Fadgen, Bachelor of Science, BioFire Diagnostics, LLC (Employee) Lisa Ogden, BS, BioFire Diagnostics, LLC (Employee) Jeremy P. Green, BS, BioFire Diagnostics, LLC (Employee, Shareholder) Stephanie A. Thatcher, MS, BioFire Diagnostics (Employee) Rebecca C. Young, MS, BioFire Diagnostics, LLC (Employee) Brandon Hoelcle, BS, ZeptoMetrix, LLC (Employee)

Офтальмологические проявления герпесвирусной инфекции у собак

This article describes the main aspects of the epizootology and pathogenesis of Cahv-1 (canine herpesvirus), also, the clinical forms of manifestations of pathology in dogs of different ages and physiological status are described. Particular attention is paid to ocular pathologies developing at Cahv-1, such as herpetic conjunctivitis, blepharitis, ulcerative and stromal keratitis. The features of the diagnosis and differentiation of these pathologies are described. The systematic and local medicines used by us in the practice of treating dogs with herpetic eye, the principles and algorithms of their prescription are presented. The difficulties of diagnostics Cahv-1 are described, and the reasons for frequent false-negative results during PCR explained in the article. Besides additional laboratory verification methods for Cahv-1 as well as methods of prevention of herpetic infection of dogs are indicated.

Fusarium Endophthalmitis: About a Case of Enucleation

Fungal eye damages are rare but severe diseases that cause corneal opacity and blindness. The most common pathogens of such damages are Fusarium and Aspergillus. Fusarium is ubiquitous mold found commonly in soil and organic debris. The risk factors for fungal eye damages are trauma (plants, soil, metallic or foreign bodies), corneal surgery (keratoplasty), disruption of corneal epithelium, contact lens wear, and immunosuppressed patients. Clinical suspicion of fungal keratitis is helpful because the diagnosis is difficult to reach based on a laboratory verification, with corneal scraping in adequate culture medium and PCR. Fusarium sp are generally resistant to most antifungal drugs. Despite medical therapy with topical natamycin and voriconazole, surgery is often required with antifungal intracorneal injection, corneal transplantation, and enucleation. A 37-year-old patient presented with a trauma of cornea with a metallic piece was examined in this study. Nine months after local treatment, he complained of painful ocular lesion with a hypopyon. He was treated by intravitreal injection of vancomycin. A corneal scrapping showed hyphae of Fusarium proliferatum. He was treated with amphotericin B and voriconazole; however, no convincing efficacy was achieved and the unbearable eye pain persisted and, unfortunately, he was diagnosed with hepatic cytolysis. Due to the treatment failure, therefore, the enucleation was required and the pathological examination of the eye was found negative.

Analysis of temporal and spatial distribution characteristics of ammonium chloride smoke particles in confined spaces

In response to the demand for short-range detection of anti-smoke environment interference by laser fuzes, this study proposes a smoke environment simulation of non-uniform continuous point source diffusion and investigates an experimental laboratory smoke environment using an ammonium chloride smoke agent. The particle size distribution, composition, and mass flow distribution of the smoke were studied. Based on a discrete phase model and a k-ε turbulence model, a numerical simulation was developed to model the smoke generation and diffusion processes of the smoke agent in a confined space. The temporal and spatial distribution characteristics of the smoke mass concentration, velocity, and temperature in the space after smoke generation were analyzed, and the motion law governing the smoke diffusion throughout the entire space was summarized. Combined with the experimental verification of the smoke environment laboratory, the results showed that the smoke plume changed from fan-shaped to umbrella-shaped during smoke generation, and then continued to spread around. Meanwhile, the mass concentration of smoke in the space decreased from the middle outward; the changes in temperature and velocity were small and stable. In the diffusion stage (after 900 s), the mass concentration of smoke above 0.8 m was relatively uniform across an area of smoke that was 12 m thick. The concentration decreased over time, following a consistent decreasing trend, and the attenuation was negligible in a very short time. Therefore, this system was suitable for conducting experimental research on laser fuzes in a smoke environment. Owing to the stability of the equipment and facilities, the setup could reproduce the same experimental smoke environment by artificially controlling the smoke emission of the smoke agent. Overall, this work provides a theoretical reference for subsequent research efforts regarding the construction of uniform smoke environments and evaluating laser transmission characteristics in smoky environments.

Paired sensitivity analysis of four SARS-CoV-2 serological immunoassays in a longitudinal cohort of convalescent hospital staff.

SARS-CoV-2 serological testing has seen extensive academic and clinical use from investigating correlates of immunity to seroprevalence, convalescent plasma and vaccine trials. Interpretation of these studies will depend on robust validation of the longitudinal sensitivities of these assays, especially in the context of mild disease which makes up the majority of the Coronavirus Disease 2019 (COVID-19) caseload. Hospital staff (n = 94) returning to work following polymerase chain reaction confirmed COVID-19 were offered antibody testing to assist with laboratory verification. Initial specimens were collected at median 29 days post-symptom onset and run on the Roche, Abbott, Siemens and DiaSorin platforms. Re-sampling occurred at median 142 days from a subset of the initial cohort (n = 62) that had volunteered to provide further serum samples to assist in longitudinal sensitivity analysis. Samples that were not run across all four platforms were excluded from analysis. Comparative sensitivity analysis was conducted on 89/94 of the initial specimens and 55/62 of the repeat specimens. Sensitivity at initial sampling ranged from 78 to 87% across platforms. At re-sampling, sensitivities were: 100% (Roche), 45% (Abbott), 100% (Siemens), and 80% (DiaSorin). Paired analysis using the longitudinal cohort (n = 55) demonstrated stable or increasing median assay values on three platforms, with a clear reduction seen only on the Abbott platform (4.78 to 1.34) with corresponding sensitivity drop-off (81.8% to 45.4%). The Abbott assay demonstrated sensitivity drop-off and decrease in median assay signal below detection threshold at four to five months. This has implications on the interpretation and design of future studies.

Laboratory Verification of Electron‐Scale Reconnection Regions Modulated by a Three‐Dimensional Instability

AbstractDuring magnetic reconnection in collisionless space plasma, the electron fluid decouples from the magnetic field within narrow current layers, and theoretical models for this process can be distinguished in terms of their predicted current layer widths. From theory, the off‐diagonal stress in the electron pressure tensor is related to the thermal noncircular orbit motion of electrons around the magnetic field lines. This stress becomes significant when the width of the reconnecting current layer approaches the small characteristic length scale of the electron motion. To aid in situ spacecraft and numerical investigations of reconnection, the structure of the electron diffusion region is here investigated using the Terrestrial Reconnection Experiment. In agreement with the closely matched kinetic simulations, laboratory observations reveal the presence of electron‐scale current layer widths. Although the layers are modulated by a current‐driven instability, three‐dimensional simulations demonstrate that it is the off‐diagonal stress that is responsible for breaking the frozen‐in condition of the electron fluid.

Pharmacophore based in silico study with laboratory verification-environmental explanation of prostate cancer recurrence.

The prediction of harmful effects can guide research on the health hazards of environmental pollutants. The development of a computer-aided drug design in pharmacological technology and omics database remarkably facilitates the prediction of the possible harmful effects of hazardous substances. In this study, the pharmacophore target database based on molecular structure served as a bridge between pollutants and genes and combined with the omics database and molecular pathway enrichment technology to predict the potential prostatic cancer-promoting effect of dibutyl phthalate. Cell experiments and gene expression were carried out to verify the previous prediction, and the characteristics of harmful effects were further explored. Low concentrations of dibutyl phthalate may have androgen-independent prostate cancer-promoting effects, which may put patients receiving androgen deprivation therapy in danger. This study suggests the potential negative effects of phthalates on prostate cancer and a method for predicting harmful effects on the basis of pharmacology technology.

A Cavopulmonary Assist Device for Long-Term Therapy of Fontan Patients

Treatment of univentricular hearts remains restricted to palliative surgical corrections (Fontan pathway). The established Fontan circulation lacks a subpulmonary pressure source and is commonly accompanied by progressively declining hemodynamics. A novel cavopulmonary assist device (CPAD) may hold the potential for improved therapeutic management of Fontan patients by chronic restoration of biventricular equivalency. This study aimed at translating clinical objectives toward a functional CPAD with preclinical proof regarding hydraulic performance, hemocompatibility and electric power consumption. A prototype composed of hemocompatible titanium components, ceramic bearings, electric motors, and corresponding drive unit was manufactured for preclinical benchtop analysis: hydraulic performance in general and hemocompatibility characteristics in particular were analyzed in-silico (computational fluid dynamics) and validated in-vitro. The CPAD's power consumption was recorded across the entire operational range. The CPAD delivered pressure step-ups across a comprehensive operational range (0-10 L/min, 0-50 mm Hg) with electric power consumption below 1.5 W within the main operating range. In-vitro hemolysis experiments (N=3) indicated a normalized index of hemolysis of 3.8 ± 1.6 mg/100 L during design point operation (2500 rpm, 4 L/min). Preclinical investigations revealed the CPAD's potential for low traumatic and thrombogenic support of a heterogeneous Fontan population (pediatric and adult) with potentially accompanying secondary disorders (e.g., elevated pulmonary vascular resistance or systemic ventricular insufficiency) at distinct physical activities. The low power consumption implied adequate settings for a small, fully implantable system with transcutaneous energy transfer. The successful preclinical proof provides the rationale for acute and chronic in-vivo trials aiming at the confirmation of laboratory findings and verification of hemodynamic benefit.

Design and alignment of a laser launch telescope in a two afocal configuration

Laser launch telescopes are optical systems forming a reference beacon in the sky, to be used as a reference for ground telescope adaptive optics. One of the requirement of the system is that the laser beam should have a radius as small as possible at the target distance where the telescope detects the beacon. This is not trivial given the Gaussian nature of laser beams. Traditionally, laser launch telescopes consists of a simple afocal. Its magnification sets the output beam waist to an optimal radius that limits the laser beam divergence. We propose a configuration consisting of a combination of two afocal systems, each with a controlled defocus. Our system provides enough degrees of freedom to displace the waist at any distance in the sky and to achieve a smaller beam radius at the target distance. After presenting the theoretical concept of the combination, this paper describes the practical implementation of the system. We start by describing the design process and the expected performances. Then, the alignment and experimental verification process are emphasized. In particular, the verification of the controlled defocus is challenging as it cannot be done simply by putting a detector at several km from the optical system. Instead, the verification in laboratory is performed by performing interferometric measurement for different defocus and comparing them to theoretical simulations. The laser launch telescope will be used in various meteorological conditions. We describe the impact of thermal variations and how it can be compensated.

Development and implementation of an LIS-based validation system for autoverification toward zero defects in the automated reporting of laboratory test results

BackgroundValidation of the autoverification function is one of the critical steps to confirm its effectiveness before use. It is crucial to verify whether the programmed algorithm follows the expected logic and produces the expected results. This process has always relied on the assessment of human–machine consistency and is mostly a manually recorded and time-consuming activity with inherent subjectivity and arbitrariness that cannot guarantee a comprehensive, timely and continuous effectiveness evaluation of the autoverification function. To overcome these inherent limitations, we independently developed and implemented a laboratory information system (LIS)-based validation system for autoverification.MethodsWe developed a correctness verification and integrity validation method (hereinafter referred to as the "new method") in the form of a human–machine dialog. The system records personnel review steps and determines whether the human–machine review results are consistent. Laboratory personnel then analyze the reasons for any inconsistency according to system prompts, add to or modify rules, reverify, and finally improve the accuracy of autoverification.ResultsThe validation system was successfully established and implemented. For a dataset consisting of 833 rules for 30 assays, 782 rules (93.87%) were successfully verified in the correctness verification phase, and 51 rules were deleted due to execution errors. In the integrity validation phase, 24 projects were easily verified, while the other 6 projects still required the additional rules or changes to the rule settings. Taking the Hepatitis B virus test as an example, from the setting of 65 rules to the automated releasing of 3000 reports, the validation time was reduced from 452 (manual verification) to 275 h (new method), a reduction in validation time of 177 h. Furthermore, 94.6% (168/182) of laboratory users believed the new method greatly reduced the workload, effectively controlled the report risk and felt satisfied. Since 2019, over 3.5 million reports have been automatically reviewed and issued without a single clinical complaint.ConclusionTo the best of our knowledge, this is the first report to realize autoverification validation as a human–machine interaction. The new method effectively controls the risks of autoverification, shortens time consumption, and improves the efficiency of laboratory verification.

Research on all-optical redundancy networks underground coal mines

In view of the serious environmental interference of coal mine underground, the inconvenient power supply of underground equipment and the existence of passive serial series series number of existing F5G underground network network, explore a new coal mine underground all-optical network redundancy technology networking scheme, realize the multi-stage series of passive light branches of the mine, Solve the problem of low number of underground optical branches in series and anti-interference of communication. Based on the principle of all-optical network network, this paper expounds the redundancy protection mechanism of all-optical network group, and designs a wide-ranging coverage scheme of fiber optic whole mine through precision calculation and analysis. Through laboratory verification and coal mine roadway simulation experimental data show that the all-optical redundancy technology network scheme can realize the underground passive light multi-stage serialization, while ensuring the priority and reliability of underground gas system. At the same time, the priority and reliability of the underground gas system are guaranteed; the scheme parameter comparison table is suitable for various types of coal mines and can be used as a reference for coal mine users in the construction of underground all-optical networks.

Exploring the use of machine learning to predict metrics related to asphalt mixture performance

Agencies responsible for construction and maintenance of roadways often use some measure of performance to qualify asphalt mixtures before being used in construction. As of this writing, the state of Texas uses the Hamburg wheel tracking test and indirect tensile strength test to qualify a hot mix asphalt produced for roadway construction and maintenance. Optimizing the mixture design to produce mixtures with the desired performance criteria has been a topic of interest for asphalt researchers and industry personnel. This study explores the use of machine learning methods to estimate the rut depth from the Hamburg wheel tracking test and the indirect tensile strength from the mixture design and volumetric information. Support vector regression analysis and decision tree based ensemble methods, including bagging, random forests, extra-trees, and gradient boosting algorithms were trained with data collected by the Texas Department of Transportation for quality control and quality assurance purposes. Metrics related to mixture design including aggregate gradation and absorption, asphalt binder content and performance grade, use of warm mix asphalt, recycled materials, and laboratory-molded density as well as test information, such as number of wheel-passes applied in the Hamburg wheel tracking test, were used as input variables. The analysis showed that all of the machine learning algorithms adopted in this study were able to estimate the mixture performance criteria from the mixture design and volumetric properties when the models were trained with curated and sufficient data. While extra-trees provided the best performance in terms of the coefficient of determination, gradient boosting and support vector regression models were found to learn from the imbalanced data better than the other methods. This study offers opportunities for the development of data-driven performance-oriented mixture design optimization technique that can potentially replace the trial and error, mostly experience based, and time consuming processes preceding the laboratory verification during the mix design process.

Bridge influence surface identification method considering the spatial effect of vehicle load

Bridge influence surface is an important tool to study the bridge responses under the moving loads, which contains tremendous structural information. The structural deterioration during the service life would induce the variation of the bridge influence surface, which makes it essential to identify the influence surface exactly from the field measured data under moving vehicle loads. This paper firstly summarizes current development of bridge influence surface identification methods and classifies the methods in which the vehicle is respectively equivalent to line loads and concentrated loads. After that, the actual spatial distribution of the vehicle load is considered, based on which a new identification method is presented to solve the boundary problem of current influence surface identification methods. Then a numerical slab model with two fixed ends is illustrated to prove the validity of the method, and the accuracy and identifiable region of different methods in this condition are compared with the other methods. Influence factors of identification accuracy including noise level, axle number of vehicle and loading point are analyzed. Finally, laboratory verification using the same slab model is prepared to verify the effectiveness of the proposed identification method. Results of this study provide an effective identification method of bridge influence surface with very high identification accuracy, which can be used to full bridge influence surface test.

New Osmotic Tensiometer Development

Abstract Climatic variations induce negative pore-water pressure or soil suction oscillations in unsaturated soil with daily and seasonal cycles. The dramatic suction changes of unsaturated soil in shallow depths can lead to engineering failures. However, suction measurements using conventional water-based tensiometers are limited to 98-kPa suction that is due to water cavitation. Therefore, they are not able to capture variations of high suction values near the ground surface. A newly proposed osmotic tensiometer was developed using a cross-linked polymer-water solution to allow the high suction measurement range and provide a reliable and consistent suction response under long-term field monitoring. The unique swelling behavior of the polymer-water solution extends the suction measurement capacity to suction values above 1.5 MPa. Laboratory verification and calibration were carried out with centrifuge (covers the lower range of suction measurement from 0.66 to 250 kPa) and WP4C potentiometer (covers the higher range of suction measurement beyond 250 kPa). The proposed osmotic tensiometer can measure rapid suction changes during drying and wetting paths. Long-term laboratory monitoring using the submerged osmotic tensiometer in a deionized water reservoir demonstrated reliable and consistent suction measurements. Osmotic pressure decay was observed after a long testing period because of the leakage of polymer particles through the high air-entry ceramic disc. A series of parametric studies was performed to explore the optimal tensiometer configuration to minimize the pressure decay. Polymer adsorption measurements from ultraviolet-visible spectrometry were used to quantify the polymer leakage. The newly proposed osmotic tensiometer is expected to capture field suction changes that are due to rainfall precipitation (wetting) and evaporation (drying) and provide long-term, accurate, and consistent suction measurements for geotechnical engineering applications.

Grouting below Subterranean Water: Erosional Stability Test.

The article is focused on the medium-term negative effect of groundwater on the underground grout elements. This is the physical–mechanical effect of groundwater, which is known as erosion. We conduct a laboratory verification of the erosional resistance of grout mixtures. A new test apparatus was designed and developed, since there is no standardized method for testing at present. An erosion stability test of grout mixtures and the technical solutions of the apparatus for the test’s implementation are described. This apparatus was subsequently used for the experimental evaluation of the erosional stability of silicate grout mixtures. Grout mixtures with activated and non-activated bentonite are tested. The stabilizing effect of cellulose relative to erosion stability has been also investigated. The specimens of grout mixtures are exposed to flowing water stress for a certain period of time. The erosional stabilities of the grout mixtures are assessed on the basis of weight loss (WL) as a percentage of initial specimen weight. The lower the grout mixture weight loss, the higher its erosional stability and vice versa.

Eco-Friendly and Sustainable Process for Converting Hydrous Bioethanol to Butanol

The purpose of the study was the development of water-resistant catalyst and catalytic processes for the conversion of hydrous ethanol to 1-butanol. Water, in hydrous ethanol, strongly inhibits conversion to 1-butanol on solid catalysts. In this study, the nonstoichiometric P-deficient hydroxyapatite containing carbonate anions (C-HAP), Ca10−x/2(PO4)6−x(CO3)x(OH)2, displayed good performance in the Guerbet condensation of hydrated ethanol to 1-butanol, after proper stabilization of reaction conditions. Hydrous ethanol (96 wt%) was converted on C-HAP formed as extrudates with silica binder at 400 °C and weight hour space velocity (WHSV) = 0.5–1.0 h−1 to yield 21–23% 1-butanol and 73–74% selectivity. It displayed stable operation for up to 170 h on streams conducted in bench and mini-pilot rigs with catalyst loadings of 2 and 50 cm3, respectively. The process simulation employed the recycling of ethanol without laboratory verification to reach 68% theoretical yield of 1-butanol. The techno-economic analysis demonstrated the feasibility of this process, showing that it may be profitable depending on the prices of hydrated ethanol and 1-butanol.

Sound Source Acquisition and Location System Based on DSP and FPGA

According to the requirements of audio signal acquisition and conversion, sound source location in complex environment, a sound source collention and positioning system which based on DSP and FPGA is designed. The system adopts low noise MEMS microphone sensor to form microphone array, DSP chip as the core controller, beam forming algorithm as the core algorithm of the system. Through the application of high precision ADC chip to carry out synchronous sampling and conversion of 64 channels of audio signals, simultaneously, the use of low-cost, high-speed FPGA chip to achieve batch data acquisition and caching. The real-time data upload is realized by fast Ethernet controller to ensure the non-blocking transmission of large traffic data. Through the laboratory test, the analysis and verification of the experimental data, the system works stably and meets the design requirements.

Laboratory Verification of a BRCA1 and BRCA2 Massively Parallel Sequencing Assay from Wet Bench to Bioinformatics for Germline DNA Analysis.

Introduction A robust genetic test for BRCA1 and BRCA2 genes is necessary for the diagnosis, prognosis, and treatment of patients with hereditary breast and ovarian cancer. We evaluated a commercial amplicon-based massively parallel sequencing (MPS) assay, BRCA MASTR Plus on the MiSeq platform, for germline BRCA genetic testing. Methods This study was performed on 31 DNA from cell lines and proficiency testing samples to establish the accuracy of the assay. A reference cell line DNA, NA12878 was used to determine the reproducibility of the assay. Discordant MPS result was resolved orthogonally by the current gold-standard Sanger sequencing method. Results The analytical accuracy, sensitivity, and specificity for variant detection were 93.55, 92.86, and 100.00%, respectively. Both sequencing depth and variant allele frequencies were highly reproducible by comparing the NA12878 DNA tested in three separate runs. The single discordant result, later confirmed by Sanger sequencing was due to the inability of the MASTR Reporter software to identify a 40-bp deletion in BRCA1 . Conclusion The BRCA MASTR Plus assay on the MiSeq platform is accurate and reproducible for germline BRCA genetic testing, making it suitable for use in a clinical diagnostic laboratory. However, Sanger sequencing may still serve as a confirmatory method to improve diagnostic capability of the MPS assay.

Development of an indirect thrust stand based on a cantilever beam

There is a large number of missions that have been or will be launched soon that utilize the electric propulsion (EP), which is considered a key technology for applications in present and future space missions. Accomplishing an accurate measure of the thrust is a key aspect of the laboratory verification of EP systems. In the case of ground conditions and direct measurements, it is complicated to verify the thrusters, especially for some high power (>5 kW) thrusters. For this reason, we have developed an indirect method for measuring thrust. We have carried out an experiment with a Hall effect thruster (operated in the 250 W power range) and compared results against direct thrust measurements. The difficulties in the indirect measurement are analyzed, which provides a basis for the development of indirect thrust measurement.