Additively manufactured components are gaining popularity in aerospace, automotive and medical engineering applications. Additive manufacturing (AM) offers tremendous cost advantages over traditional ...manufacturing methods. However, inter- and intra-layer defects are observed in AM components. Moreover, the lack of appropriate testing methods for assessing the integrity of AM components deters its use, despite the several functional advantages it has to offer. Non-destructive testing (NDT) forms the most common and convenient way of inspecting parts. In this paper, a laser ultrasonic technique for the inspection of AM components is proposed. The results demonstrate laser ultrasonic testing (LUT) as a promising method for the non-contact inspection of additive manufactured components. Furthermore, the results were validated using X-ray computed tomography (CT) and ultrasonic immersion testing (UIT). The sample used in this study was manufactured through selective laser melting (SLM) AM process with built-in holes representing defects.
COVID-19 testing: One size does not fit all Mina, Michael J; Andersen, Kristian G
Science (American Association for the Advancement of Science),
01/2021, Letnik:
371, Številka:
6525
Journal Article
Recenzirano
Odprti dostop
To control the pandemic, testing should be considered a public health tool
Tests for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were developed within days of the release ...of the virus genome (
1
). Multiple countries have been successful at controlling SARS-CoV-2 transmission by investing in large-scale testing capacity (
2
). Most testing has focused on quantitative polymerase chain reaction (qPCR) assays, which are capable of detecting minute amounts of viral RNA. Although powerful, these molecular tools cannot be scaled to meet demands for more extensive public health testing. To combat COVID-19, the “one-size-fits-all” approach that has dominated and confused decision-making with regard to testing and the evaluation of tests is unsuitable: Diagnostics, screening, and surveillance serve different purposes, demand distinct strategies, and require separate approval mechanisms. By supporting the innovation, approval, manufacturing, and distribution of simpler and cheaper screening and surveillance tools, it will be possible to more effectively limit the spread of COVID-19 and respond to future pandemics.
In 1995, the American Society of Human Genetics (ASHG) and American College of Medical Genetics and Genomics (ACMG) jointly published a statement on genetic testing in children and adolescents. In ...the past 20 years, much has changed in the field of genetics, including the development of powerful new technologies, new data from genetic research on children and adolescents, and substantial clinical experience. This statement represents current opinion by the ASHG on the ethical, legal, and social issues concerning genetic testing in children. These recommendations are relevant to families, clinicians, and investigators. After a brief review of the 1995 statement and major changes in genetic technologies in recent years, this statement offers points to consider on a broad range of test technologies and their applications in clinical medicine and research. Recommendations are also made for record and communication issues in this domain and for professional education.
Toxicity Testing in the 21st Century National Research Council; Division on Earth and Life Studies; Institute for Laboratory Animal Research ...
03/2009
eBook
Odprti dostop
Advances in molecular biology and toxicology are paving the way for major improvements in the evaluation of the hazards posed by the large number of chemicals found at low levels in the environment. ...The National Research Council was asked by the U.S. Environmental Protection Agency to review the state of the science and create a far-reaching vision for the future of toxicity testing. The book finds that developing, improving, and validating new laboratory tools based on recent scientific advances could significantly improve our ability to understand the hazards and risks posed by chemicals. This new knowledge would lead to much more informed environmental regulations and dramatically reduce the need for animal testing because the new tests would be based on human cells and cell components. Substantial scientific efforts and resources will be required to leverage these new technologies to realize the vision, but the result will be a more efficient, informative and less costly system for assessing the hazards posed by industrial chemicals and pesticides.
IMPORTANCE: Understanding the effect of serum antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on susceptibility to infection is important for identifying at-risk ...populations and could have implications for vaccine deployment. OBJECTIVE: The study purpose was to evaluate evidence of SARS-CoV-2 infection based on diagnostic nucleic acid amplification test (NAAT) among patients with positive vs negative test results for antibodies in an observational descriptive cohort study of clinical laboratory and linked claims data. DESIGN, SETTING, AND PARTICIPANTS: The study created cohorts from a deidentified data set composed of commercial laboratory tests, medical and pharmacy claims, electronic health records, and hospital chargemaster data. Patients were categorized as antibody-positive or antibody-negative according to their first SARS-CoV-2 antibody test in the database. MAIN OUTCOMES AND MEASURES: Primary end points were post-index diagnostic NAAT results, with infection defined as a positive diagnostic test post-index, measured in 30-day intervals (0-30, 31-60, 61-90, >90 days). Additional measures included demographic, geographic, and clinical characteristics at the time of the index antibody test, including recorded signs and symptoms or prior evidence of coronavirus 2019 (COVID) diagnoses or positive NAAT results and recorded comorbidities. RESULTS: The cohort included 3 257 478 unique patients with an index antibody test; 56% were female with a median (SD) age of 48 (20) years. Of these, 2 876 773 (88.3%) had a negative index antibody result, and 378 606 (11.6%) had a positive index antibody result. Patients with a negative antibody test result were older than those with a positive result (mean age 48 vs 44 years). Of index-positive patients, 18.4% converted to seronegative over the follow-up period. During the follow-up periods, the ratio (95% CI) of positive NAAT results among individuals who had a positive antibody test at index vs those with a negative antibody test at index was 2.85 (95% CI, 2.73-2.97) at 0 to 30 days, 0.67 (95% CI, 0.6-0.74) at 31 to 60 days, 0.29 (95% CI, 0.24-0.35) at 61 to 90 days, and 0.10 (95% CI, 0.05-0.19) at more than 90 days. CONCLUSIONS AND RELEVANCE: In this cohort study, patients with positive antibody test results were initially more likely to have positive NAAT results, consistent with prolonged RNA shedding, but became markedly less likely to have positive NAAT results over time, suggesting that seropositivity is associated with protection from infection. The duration of protection is unknown, and protection may wane over time.
The dawn of consumer‐directed testing Ramos, Erica; Weissman, Scott M.
American journal of medical genetics. Part C, Seminars in medical genetics,
March 2018, 2018-03-00, 20180301, Letnik:
178, Številka:
1
Journal Article
Odprti dostop
As the public's interest in genetics and genomics has increased, there has been corresponding and unprecedented growth in direct‐to‐consumer genetic testing (DTC‐GT). Although regulatory concerns ...have limited true DTC‐GT available without a physician order, the paradigm has shifted to a model of consumer‐directed genetic testing (CD‐GT) in which patients are researching testing options and requesting specific genetic testing from their health‐care providers. However, many nongenetics health‐care providers do not have the background, education, interest, or time to order and/or interpret typical clinical genetic testing, let alone DTC‐GT. The lines between CD‐GT, DTC‐GT, and traditional clinical genetic testing are also blurring with the same types of tests available in different settings (e.g., carrier screening) and tests merging medical and nonmedical results, increasing the complexity for consumer decision‐making and clinician management. The genetics community has the training to work with CD‐GT, but there has been a hesitancy to commit to working with these results and questions about what to do when consumers have more complicated asks, like interpretation of raw data. Additionally, at the rate with which CD‐GT is growing, there are questions about having sufficient genetics professionals to meet the potential genetic counseling demand. While there are many complex questions and challenges, this market represents a chance for the genetics community to address and unmet need. We will review the history of the CD‐GT/DTC‐GT market and outline the issues and opportunities our profession is facing.
As one of the major approaches in combating the COVID-19 pandemics, the availability of specific and reliable assays for the SARS-CoV-2 viral genome and its proteins is essential to identify the ...infection in suspected populations, make diagnoses in symptomatic or asymptomatic individuals, and determine clearance of the virus after the infection. For these purposes, use of the quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) for detection of the viral nucleic acid remains the most valuable in terms of its specificity, fast turn-around, high-throughput capacity, and reliability. It is critical to update the sequences of primers and probes to ensure the detection of newly emerged variants. Various assays for increased levels of IgG or IgM antibodies are available for detecting ongoing or past infection, vaccination responses, and persistence and for identifying high titers of neutralizing antibodies in recovered individuals. Viral genome sequencing is increasingly used for tracing infectious sources, monitoring mutations, and subtype classification and is less valuable in diagnosis because of its capacity and high cost. Nanopore target sequencing with portable options is available for a quick process for sequencing data. Emerging CRISPR-Cas-based assays, such as SHERLOCK and AIOD-CRISPR, for viral genome detection may offer options for prompt and point-of-care detection. Moreover, aptamer-based probes may be multifaceted for developing portable and high-throughput assays with fluorescent or chemiluminescent probes for viral proteins. In conclusion, assays are available for viral genome and protein detection, and the selection of specific assays depends on the purposes of prevention, diagnosis and pandemic control, or monitoring of vaccination efficacy.
During the COVID-19 pandemics, sensitive and reliable assays for SARS-CoV-2 detection are essential for screening the population, identifying asymptomatic individuals, making diagnoses, monitoring treatment responses, and determining viral clearance. This review summarizes the principles, advantages, disadvantages, and specific applications of currently available assays for detection of the viral nucleotide, genome or proteins, as well as host antibody responses, and provide overall guidelines for selection of optimal assays for specific usage.
Wire rope inspection by nondestructive testing methods, sensors and signal processing techniques are mainly reviewed in this paper. Owing to the difference of physical mechanism and testing ...principles, magnetic flux leakage, eddy current, acoustic emission and ultrasonic guide wave testing as well as other inspection methods for steel wire rope are summarized. Then, the commonly and frequently used testing sensors of inductive coil, hall element, magnetoresistive sensors and others are compared in the perspective of their corresponding operating principles, development situation, advantages and disadvantages. Furthermore, signal processing techniques including the signal filtering techniques such as the time and frequency analysis methods, quantitative data processing methods such as the machine learning and defect classification are studied. Finally, the challenges and future developing trends of wire rope inspection in practical applications are discussed.
Software testing is a vital part of software engineering process. Automated testing makes this process more accurate and more efficient. For automated testing, many different testing tools were ...introduced. Due to the large number and the variety of testing tools, selecting the appropriate tools became a difficult confusable task. This research aims at developing a comprehensive taxonomy for testing tools that cover a broad range of testing tools criteria. This comprehensive view would help software developers and software vendors to specify the testing tool/s they need/develop accurately. In details, the framework includes two main parts: (1) comprehensive taxonomy of testing tools; (2) multi-criteria selection method. The first part covers different criteria of testing tools. Because these criteria are large in numbers, wide and variant, a taxonomy of these criteria is needed. This taxonomy will help developers distinguish among testing tools based on a wide spectrum of different criteria. The second part of the framework is a multi-criteria selection method; that enables software developers to choose the appropriate testing tool using a systematic and adequate automated manner. The selection method employs scientific two well-known methods of multi-criteria decision-making techniques; Analytic Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). The testing tools taxonomy is well validated by academic professionals in software engineering and achieved good scores in terms of significance, usefulness and comprehension. Academics reported that the taxonomy is slightly complex and needs to be simplified. The selection method was validated using different scenarios to prove the quality of selection even in complex cases with many criteria and many alternatives.
To face the current COVID-19 pandemic, diagnostic tools are essential. It is recommended to use real-time RT-PCR for RNA viruses in order (a) to perform a rapid and accurate diagnostic, (b) to guide ...patient care and management and (c) to guide epidemiological strategies. Further studies are warranted to define the role of serological diagnosis and a possible correlation between serological response and prognosis.
The aim was to guide clinical microbiologists in the use of these diagnostic tests and clinicians in the interpretation of their results.
A search of literature was performed through PubMed and Google Scholar using the keywords SARS-CoV-2, SARS-CoV-2 molecular diagnosis, SARS-CoV-2 immune response, SARS-CoV-2 serology/antibody testing, coronavirus diagnosis.
The present review discusses performances, limitations and use of current and future diagnostic tests for SARS-CoV-2.
Real-time RT-PCR remains the reference method for diagnosis of SARS-CoV-2 infection. On the other hand, notwithstanding its varying sensitivity according to the time of infection, serology represents a valid asset (a) to try to solve possible discrepancies between a highly suggestive clinical and radiological presentation and negative RT-PCR, (b) to solve discrepancies between different PCR assays and (c) for epidemiological purposes.
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