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30 years of the Comet Assay: an overview with some new insights

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889196494 Year: Pages: 174 DOI: 10.3389/978-2-88919-649-4 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Genetics
Added to DOAB on : 2016-08-16 10:34:25
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By means of this ‘Frontiers in Genetics’ research topic, we are celebrating 30 years of the Comet Assay. The first paper on this single-cell gel electrophoresis assay was published in 1984 by O. Ostling and K.J. Johanson (Biochem. Biophys. Res. Commun. Vol.123: 291-298). The comet assay is a versatile and sensitive method for measuring single - and double-strand breaks in DNA. By including lesion-specific enzymes in the assay, its range and sensitivity are greatly increased, but it is important to bear in mind that their specificity is not absolute. The comet assay (with and without inclusion of lesion-specific enzymes) is widely used as a biomarker assay in human population studies - primarily to measure DNA damage, but increasingly also to assess the capacity of cells for DNA repair. Ostling and Johanson (Biochem. Biophys. Res. Commun., 1984) were also the first to report experiments to measure DNA repair, by simply following the decrease of DNA damage over time after challenging cells with ionising radiation. However, this approach is time-consuming and laborious as it requires an extended period of cell culture and is therefore not ideal for biomonitoring studies, which typically require high-throughput processing of many samples. As an alternative approach, the in vitro comet-based repair assay was developed: a cell extract is incubated with a DNA substrate containing specific lesions, and DNA incisions accumulate. The in vitro comet-based repair assay has been modified and improved over the past decade: it was first devised to measure base excision repair of oxidised purines in lymphocytes (Collins et al., Mutagenesis, 2001), but has since been adapted for other lesions and thus other repair pathways, as well as being applied to tissue samples in addition to cell suspensions. Even after 30 years, the comet assay is still in a growth phase, with many new users each year. Many questions are repeatedly raised, which may seem to have self-evident answers, but clearly, it is necessary to reiterate them for the benefit of the new audience, and sometimes being forced to think again about old topics can shed new light. Different applications of the comet assay are discussed in this special issue, including: genotoxicity testing in different organisms, human biomonitoring, DNA repair studies, environmental biomonitoring and clinical studies. Furthermore, we consider and where possible answer questions, including the ones raised by Raymond Tice at the 8th International Comet Assay Workshop in Perugia (Italy 2009): What is the spectrum of DNA damage detected by the various versions of the comet assay?; What are the limitations associated with each application?; What should be done to standardize the assay for biomonitoring studies?; Can the comet assay be used to monitor changes in global methylation status?; What cell types are suitable for detecting genotoxic substances and their effects in vivo and in vitro?; Can the assay be fully automated?; and more. So this ‘Frontiers in Genetics’ research topic is written for the beginner as well as for the experienced users of the comet assay.

Experimental and Numerical Studies in Biomedical Engineering

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ISBN: 9783039212477 / 9783039212484 Year: Pages: 130 DOI: 10.3390/books978-3-03921-248-4 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- General and Civil Engineering
Added to DOAB on : 2019-12-09 16:10:12
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The term ‘biomedical engineering’ refers to the application of the principles and problem-solving techniques of engineering to biology and medicine. Biomedical engineering is an interdisciplinary branch, as many of the problems health professionals are confronted with have traditionally been of interest to engineers because they involve processes that are fundamental to engineering practice. Biomedical engineers employ common engineering methods to comprehend, modify, or control biological systems, and to design and manufacture devices that can assist in the diagnosis and therapy of human diseases. This Special Issue of Fluids aims to be a forum for scientists and engineers from academia and industry to present and discuss recent developments in the field of biomedical engineering. It contains papers that tackle, both numerically (Computational Fluid Dynamics studies) and experimentally, biomedical engineering problems, with a diverse range of studies focusing on the fundamental understanding of fluid flows in biological systems, modelling studies on complex rheological phenomena and molecular dynamics, design and improvement of lab-on-a-chip devices, modelling of processes inside the human body as well as drug delivery applications. Contributions have focused on problems associated with subjects that include hemodynamical flows, arterial wall shear stress, targeted drug delivery, FSI/CFD and Multiphysics simulations, molecular dynamics modelling and physiology-based biokinetic models.

Drinking Water Quality and Human Health

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ISBN: 9783038977261 Year: Pages: 374 DOI: 10.3390/books978-3-03897-727-8 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Sociology --- Social Sciences
Added to DOAB on : 2019-04-05 10:34:31
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The quality of drinking water is paramount for public health. Despite important improvements in the last decades, access to safe drinking water is not universal. The World Health Organization estimates that almost 10% of the population in the world do not have access to improved drinking water sources. Among other diseases, waterborne infections cause diarrhea, which kills nearly one million people every year, mostly children under 5 years of age. On the other hand, chemical pollution is a concern in high-income countries and an increasing problem in low- and middle-income countries. Exposure to chemicals in drinking water may lead to a range of chronic non-communicable diseases (e.g., cancer, cardiovascular disease), adverse reproductive outcomes, and effects on children’s health (e.g., neurodevelopment), among other health effects. Although drinking water quality is regulated and monitored in many countries, increasing knowledge leads to the need for reviewing standards and guidelines on a nearly permanent basis, both for regulated and newly identified contaminants. Drinking water standards are mostly based on animal toxicity data, and more robust epidemiologic studies with accurate exposure assessment are needed. The current risk assessment paradigm dealing mostly with one-by-one chemicals dismisses the potential synergisms or interactions from exposures to mixtures of contaminants, particularly at the low-exposure range. Thus, evidence is needed on exposure and health effects of mixtures of contaminants in drinking water. Finally, water stress and water quality problems are expected to increase in the coming years due to climate change and increasing water demand by population growth, and new evidence is needed to design appropriate adaptation policies.This Special Issue of International Journal of Environmental Research and Public Health (IJERPH) focuses on the current state of knowledge on the links between drinking water quality and human health.

Keywords

Vibrio pathogens --- rural water resources --- public health --- sub-Saharan Africa --- diarrhoeal disease --- HWTS implementation --- water and sanitation --- drinking water guidance --- infant exposure --- chemical risk assessment --- duration extrapolation --- acute gastroenteritis --- risk --- tap water --- time series study --- turbidity --- urban area --- water operation data --- THMs --- cancer --- effect measure modification --- drinking water --- drinking water --- exposure assessment --- sodium --- potassium --- magnesium --- calcium --- spatial variations --- Denmark --- water safety plans --- drinking water quality --- risk management --- impact assessment --- Asia-Pacific region --- diarrhea --- fever --- cough --- Nigeria --- infant health --- drinking water --- inorganic manganese --- health-based guideline --- infants --- pharmaceuticals --- human health --- environment --- drug labels --- screening method --- LTD --- uncertainty factors --- risk assessment --- risk context --- biomonitoring --- dental health --- drinking water --- fluoride --- pharmacokinetic modeling --- waterborne disease outbreak --- simulation study --- health insurance data --- space–time detection --- drinking water --- nitrate --- cancer --- adverse reproductive outcomes --- methemoglobinemia --- thyroid disease --- endogenous nitrosation --- N-nitroso compounds --- E. coli --- monitoring --- drinking water --- water safety plan --- sanitary inspection --- gravity-fed piped water scheme --- risk management --- chlorination by-product --- France --- environmental exposure --- organic matter --- tap water --- trihalomethanes --- private wells --- groundwater --- drinking water --- animal feeding operation --- fecal coliforms --- enterococci --- E. coli --- Maryland --- nitrite --- disinfection by-product --- drinking water distribution systems --- seasonality --- atrazine --- community water system --- low birth weight --- preterm birth --- small for gestational age --- water contamination --- endocrine disruptor --- drinking water --- radioactivity --- annual effective dose --- carcinogenic --- chronic kidney disease --- end-stage renal disease --- water contaminants --- zinc --- ammonia --- chemical oxygen demand --- dissolved oxygen --- arsenic

Advances in Near Infrared Spectroscopy and Related Computational Methods

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ISBN: 9783039280520 / 9783039280537 Year: Pages: 496 DOI: 10.3390/books978-3-03928-053-7 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General) --- Analytical Chemistry
Added to DOAB on : 2020-01-30 16:39:46
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In the last few decades, near-infrared (NIR) spectroscopy has distinguished itself as one of the most rapidly advancing spectroscopic techniques. Mainly known as an analytical tool useful for sample characterization and content quantification, NIR spectroscopy is essential in various other fields, e.g. NIR imaging techniques in biophotonics, medical applications or used for characterization of food products. Its contribution in basic science and physical chemistry should be noted as well, e.g. in exploration of the nature of molecular vibrations or intermolecular interactions. One of the current development trends involves the miniaturization and simplification of instrumentation, creating prospects for the spread of NIR spectrometers at a consumer level in the form of smartphone attachments—a breakthrough not yet accomplished by any other analytical technique. A growing diversity in the related methods and applications has led to a dispersion of these contributions among disparate scientific communities. The aim of this Special Issue was to bring together the communities that may perceive NIR spectroscopy from different perspectives. It resulted in 30 contributions presenting the latest advances in the methodologies essential in near-infrared spectroscopy in a variety of applications.

Keywords

hyperspectral imaging --- variety discrimination --- Chrysanthemum --- deep convolutional neural network --- DNA --- FTIR spectroscopy --- rapid identification --- PLS-DA --- animal origin --- near-infrared hyperspectral imaging --- raisins --- support vector machine --- pixel-wise --- object-wise --- maize kernel --- hyperspectral imaging technology --- accelerated aging --- principal component analysis --- support vector machine model --- standard germination tests --- blackberries --- Rubus fructicosus --- phenolics --- carotenoids --- bioanalytical applications --- near infrared --- chemometrics --- VIS/NIR hyperspectral imaging --- corn seed --- classification --- freeze-damaged --- image processing --- imaging visualization --- wavelength selection --- NIR spectroscopy --- binary dragonfly algorithm --- ensemble learning --- quantitative analysis modeling --- NIR --- SCiO --- pocket-sized spectrometer --- cheese --- fat --- moisture --- multivariate data analysis --- Fourier-transform near-infrared spectroscopy --- glucose --- fructose --- dry matter --- partial least square regression --- Ewing sarcoma --- Fourier transform infrared spectroscopy --- FTIR --- chemotherapy --- bone cancer --- calibration transfer --- NIR spectroscopy --- PLS --- quantitative analysis model --- melamine --- FT-IR --- NIR spectroscopy --- quantum chemical calculation --- anharmonic calculation --- overtones --- combination bands --- near infrared spectroscopy --- Trichosanthis Fructus --- geographical origin --- chemometric techniques --- crude drugs --- prepared slices --- support vector machine-discriminant analysis --- near-infrared fluorescence --- fluorescent probes --- Zn(II) --- di-(2-picolyl)amine --- living cells --- cellular imaging --- near-infrared (NIR) spectroscopy --- calibration transfer --- affine invariance --- multivariate calibration --- partial least squares (PLS) --- NIR --- direct model transferability --- MicroNIR™ --- SVM --- hier-SVM --- SIMCA --- PLS-DA --- TreeBagger --- PLS --- calibration transfer --- agriculture --- photonics --- imaging --- spectral imaging --- spectroscopy --- handheld near-infrared spectroscopy --- pasta/sauce blends --- partial least squares calibration --- nutritional parameters --- bootstrapping soft shrinkage --- partial least squares --- extra virgin olive oil --- adulteration --- FT-NIR spectroscopy --- near-infrared spectroscopy --- ethanol --- anharmonic quantum mechanical calculations --- isotopic substitution --- overtones --- combinations bands --- seeds vitality --- rice seeds --- near-infrared spectroscopy --- hyperspectral image --- discriminant analysis --- near-infrared spectroscopy --- counter propagation artificial neural network --- detection --- auxiliary diagnosis --- BRAF V600E mutation --- colorectal cancer --- tissue --- paraffin-embedded --- deparaffinized --- stained --- ultra-high performance liquid chromatography --- Folin–Ciocalteu --- total hydroxycinnamic derivatives --- phytoextraction --- near-infrared spectroscopy --- origin traceability --- data fusion --- Paris polyphylla var. yunnanensis --- Fourier transform mid-infrared spectroscopy --- near-infrared spectroscopy --- aquaphotomics --- water --- light --- near infrared spectroscopy --- water-mirror approach --- perturbation --- biomeasurements --- biodiagnosis --- biomonitoring --- Vitis vinifera L. --- proximal sensing --- precision viticulture --- near infrared --- chemometrics --- non-destructive sensor --- NIRS --- osteopathy --- late preterm --- brain --- splanchnic --- Raman spectroscopy --- hyperspectral imaging --- analytical spectroscopy --- counterfeit and substandard pharmaceuticals --- DFT calculations --- chemometrics --- PLSR --- API --- lumefantrine --- artemether --- antimalarial tablets --- FT-NIR spectroscopy --- PLS-R --- water --- glucose --- test set validation --- RMSEP --- hyperspectral image processing --- perfusion measurements --- clinical classifications --- n/a

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