scholarly journals Current status and future direction for examining engineered nanoparticles in natural systems

2014 ◽  
Vol 11 (4) ◽  
pp. 351 ◽  
Author(s):  
Manuel D. Montaño ◽  
Gregory V. Lowry ◽  
Frank von der Kammer ◽  
Julie Blue ◽  
James F. Ranville
Keyword(s):  
Environmental Samples ◽  
Accurate Determination ◽  
Engineered Nanoparticles ◽  
Engineered Nanomaterials ◽  
Current Status ◽  
Environmental Matrices ◽  
New Techniques ◽  
Unique Challenge ◽  
High Background ◽  
Naturally Occurring

Environmental context The detection and characterisation of engineered nanomaterials in the environment is essential for exposure and risk assessment for this emerging class of materials. However, the ubiquitous presence of naturally occurring nanomaterials presents a unique challenge for the accurate determination of engineered nanomaterials in environmental matrices. New techniques and methodologies are being developed to overcome some of these issues by taking advantage of subtle differences in the elemental and isotopic ratios within these nanomaterials. Abstract The increasing manufacture and implementation of engineered nanomaterials (ENMs) will continue to lead to the release of these materials into the environment. Reliably assessing the environmental exposure risk of ENMs will depend highly on the ability to quantify and characterise these materials in environmental samples. However, performing these measurements is obstructed by the complexity of environmental sample matrices, physiochemical processes altering the state of the ENM and the high background of naturally occurring nanoparticles (NNPs), which may be similar in size, shape and composition to their engineered analogues. Current analytical techniques can be implemented to overcome some of these obstacles, but the ubiquity of NNPs presents a unique challenge requiring the exploitation of properties that discriminate engineered and natural nanomaterials. To this end, new techniques are being developed that take advantage of the nature of ENMs to discern them from naturally occurring analogues. This paper reviews the current techniques utilised in the detection and characterisation of ENMs in environmental samples as well as discusses promising new approaches to overcome the high backgrounds of NNPs. Despite their occurrence in the atmosphere and soil, this review will be limited to a discussion of aqueous-based samples containing ENMs, as this environment will serve as a principal medium for the environmental dispersion of ENMs.

Behavior of engineered nanoparticles in aquatic environmental samples: Current status and challenges

2021 ◽  
pp. 148560
Author(s):  
Jejal Reddy Bathi ◽  
Faegheh Moazeni ◽  
Venkata K.K. Upadhyayula ◽  
Indranil Chowdhury ◽  
Soubantika Palchoudhury ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Engineered Nanoparticles ◽  
Current Status

scholarly journals Prevalence and types of Campylobacter on poultry farms and in their direct environment

2017 ◽  
Vol 15 (6) ◽  
pp. 849-862 ◽  
Author(s):  
Franciska M. Schets ◽  
Wilma F. Jacobs-Reitsma ◽  
Rozemarijn Q. J. van der Plaats ◽  
Lianne Kerkhof-De Heer ◽  
Angela H. A. M. van Hoek ◽  
...  
Keyword(s):  
Surface Water ◽  
Species Distribution ◽  
Surface Waters ◽  
Multilocus Sequence Typing ◽  
Environmental Samples ◽  
Background Level ◽  
Environmental Matrices ◽  
High Background ◽  
Poultry Farms ◽  
Sequence Types

Abstract To study whether broiler and layer farms contribute to the environmental Campylobacter load, environmental matrices at or close to farms, and caecal material from chickens, were examined. Similarity between Campylobacter from poultry and environment was tested based on species identification and Multilocus Sequence Typing. Campylobacter prevalence in caecal samples was 97% at layer farms (n = 5), and 93% at broiler farms with Campylobacter-positive flocks (n = 2/3). Campylobacter prevalence in environmental samples was 24% at layer farms, and 29% at broiler farms with Campylobacter-positive flocks. Campylobacter was detected in soil and surface water, not in dust and flies. Campylobacter prevalence in adjacent and remote surface waters was not significantly (P > 0.1) different. Detected species were C. coli (52%), C. jejuni (40%) and C. lari (7%) in layers, and C. jejuni (100%) in broilers. Identical sequence types (STs) were detected in caecal material and soil. A deviating species distribution in surface water adjacent to farms indicated a high background level of environmental Campylobacter. STs from layer farms were completely deviant from surface water STs. The occasional detection of identical STs in broilers, wastewater at broiler farms and surface water in the farm environment suggested a possible contribution of broiler farms to the aquatic environmental Campylobacter load.

Novel FIB Use for Failure Analysis of MEMS Gyroscopes

2016 ◽  
Author(s):  
Nathan Wang ◽  
Saunil Shah ◽  
Camille Garcia ◽  
Vicente Pasating ◽  
George Perreault
Keyword(s):  
Thin Films ◽  
Integrated Circuits ◽  
Failure Analysis ◽  
New Techniques ◽  
Unique Challenge ◽  
Root Cause ◽  
Large Size ◽  
Mems Gyroscopes

Abstract MEMS samples, with their relatively large size and weight, present a unique challenge to the failure analyst as they also included thin films and microstructures used in conventional integrated circuits. This paper describes how to accommodate the large MEMS structures without skimping on the microanalyses needed to get to the root cause. Investigations of tuning folk gyroscopes were used to demonstrate these new techniques.

scholarly journals Test spectra experimental construction for evaluating gamma-spectrometry computer codes for the 235U determination

2014 ◽  
Vol 29 (suppl.) ◽  
pp. 1-7 ◽  
Author(s):  
Konstantinos Karfopoulos ◽  
Dimitrios Karangelos ◽  
Marios Anagnostakis ◽  
Simos Simopoulos
Keyword(s):  
Gamma Spectrometry ◽  
Energy Region ◽  
Environmental Samples ◽  
Activity Concentration ◽  
Germanium Detector ◽  
Computer Code ◽  
High Background ◽  
Spectrometry Analysis ◽  
Background Continuum ◽  
Concentration Levels

The determination of 235U in environmental samples from its 185.72 keV photons may require the deconvolution of the multiplet photopeak at ~186 keV, due to the co-existence of the 186.25 keV photons of 226Ra in the spectrum. Successful deconvolution depends on many parameters, such as the detector characteristics, the activity concentration of the 235U and 226Ra in the sample, the background continuum in the 186 keV energy region and the gamma-spectrometry computer code used. In this work two sets of experimental test spectra were constructed for examining the deconvolution of the multiplet photopeak performed by different codes. For the construction of the test spectra, a high-resolution low energy germanium detector was used. The first series consists of 140 spectra and simulates environmental samples containing various activity concentration levels of 235U and 226Ra. The second series consists of 280 spectra and has been derived by adding 137Cs, corresponding to various activity concentration levels, to specific first series test spectra. As the 137Cs backscatter edge is detected in the energy region of the multiplet photopeak at ~186 keV, this second series of test spectra tests the analysis of the multiplet photopeak in high background continuum conditions. The analysis of the test spectra is performed by two different g-spectrometry analysis codes: (a) spectrum unix analysis code, a computer code developed in-house and (b) analysis of germanium detector spectra, a program freely available from the IAEA. The results obtained by the two programs are compared in terms of photopeak detection and photopeak area determination.

scholarly journals Recent advances in analysis of trace elements in environmental samples by X-ray based techniques (IUPAC Technical Report)

2019 ◽  
Vol 91 (6) ◽  
pp. 1029-1063 ◽  
Author(s):  
Roberto Terzano ◽  
Melissa A. Denecke ◽  
Gerald Falkenberg ◽  
Bradley Miller ◽  
David Paterson ◽  
...  
Keyword(s):  
Trace Elements ◽  
Environmental Samples ◽  
Analytical Techniques ◽  
Anthropogenic Pollution ◽  
Chemical Extraction ◽  
Environmental Matrices ◽  
Environmental Sciences ◽  
X Ray ◽  
Environmental Media ◽  
Living Organisms

Abstract Trace elements analysis is a fundamental challenge in environmental sciences. Scientists measure trace elements in environmental media in order to assess the quality and safety of ecosystems and to quantify the burden of anthropogenic pollution. Among the available analytical techniques, X-ray based methods are particularly powerful, as they can quantify trace elements in situ. Chemical extraction is not required, as is the case for many other analytical techniques. In the last few years, the potential for X-ray techniques to be applied in the environmental sciences has dramatically increased due to developments in laboratory instruments and synchrotron radiation facilities with improved sensitivity and spatial resolution. In this report, we summarize the principles of the X-ray based analytical techniques most frequently employed to study trace elements in environmental samples. We report on the most recent developments in laboratory and synchrotron techniques, as well as advances in instrumentation, with a special attention on X-ray sources, detectors, and optics. Lastly, we inform readers on recent applications of X-ray based analysis to different environmental matrices, such as soil, sediments, waters, wastes, living organisms, geological samples, and atmospheric particulate, and we report examples of sample preparation.

scholarly journals Using the Systematic Review Methodology To Evaluate Factors That Influence the Persistence of Influenza Virus in Environmental Matrices

2010 ◽  
Vol 77 (3) ◽  
pp. 1049-1060 ◽  
Author(s):  
C. K. Irwin ◽  
K. J. Yoon ◽  
C. Wang ◽  
S. J. Hoff ◽  
J. J. Zimmerman ◽  
...  
Keyword(s):  
Systematic Review ◽  
Influenza Virus ◽  
Environmental Samples ◽  
Disease Ecology ◽  
Environmental Science ◽  
Virus Concentration ◽  
Linear Regression Models ◽  
Environmental Matrices ◽  
Systematic Review Methodology ◽  
Human Influenza Virus

ABSTRACTUnderstanding factors that influence persistence of influenza virus in an environment without host animals is critical to appropriate decision-making for issues such as quarantine downtimes, setback distances, and eradication programs in livestock production systems. This systematic review identifies literature describing persistence of influenza virus in environmental samples, i.e., air, water, soil, feces, and fomites. An electronic search of PubMed, CAB, AGRICOLA, Biosis, and Compendex was performed, and citation relevance was determined according to the aim of the review. Quality assessment of relevant studies was performed using criteria from experts in virology, disease ecology, and environmental science. A total of 9,760 abstracts were evaluated, and 40 appeared to report the persistence of influenza virus in environmental samples. Evaluation of full texts revealed that 19 of the 40 studies were suitable for review, as they described virus concentration measured at multiple sampling times, with viruses detectable at least twice. Seven studies reported persistence in air (six published before 1970), seven in water (five published after 1990), two in feces, and three on surfaces. All three fomite and five air studies addressed human influenza virus, and all water and feces studies pertained to avian influenza virus. Outcome measurements were transformed to half-lives, and resultant multivariate mixed linear regression models identified influenza virus surviving longer in water than in air. Temperature was a significant predictor of persistence over all matrices. Salinity and pH were significant predictors of persistence in water conditions. An assessment of the methodological quality review of the included studies revealed significant gaps in reporting critical aspects of study design.

Therapeutic delivery using cell-penetrating peptides

2013 ◽  
Vol 5 (3) ◽  
Author(s):  
Rupa R. Sawant ◽  
Niravkumar R. Patel ◽  
Vladimir P. Torchilin
Keyword(s):  
Small Molecules ◽  
Therapeutic Agent ◽  
Intracellular Delivery ◽  
Cell Penetrating Peptides ◽  
Current Status ◽  
Unique Challenge ◽  
Large Molecules ◽  
Therapeutic Delivery ◽  
Cell Penetrating ◽  
Stimuli Sensitive

AbstractIntracellular delivery of promising therapeutic agents as well as nanocarriers presents a unique challenge. However, with the discovery of the cell-penetrating peptides (CPPs), overcoming this obstacle seems more plausible. In many cases, CPPs conjugated with therapeutic agent or therapeutic agent loaded-nanoparticles have shown promising results via increased cellular uptake. In this review, the current status of CPPs for the intracellular delivery of not just potential therapeutic small molecules but also large molecules like peptides, nucleic acids and nanocarriers is discussed. In addition, the design of ‘smart stimuli-sensitive nanocarrier’ to overcome the non-target-specificity of CPPs is also described.

scholarly journals Feline transfusion practice in South Africa : current status and practical solutions : continuing education

1999 ◽  
Vol 70 (3) ◽  
Author(s):  
T. Dippenaar
Keyword(s):  
South Africa ◽  
Transfusion Practice ◽  
Blood Type ◽  
Current Status ◽  
Hydration Status ◽  
Blood Collection ◽  
Transfusion Rate ◽  
Transfusion Therapy ◽  
Naturally Occurring ◽  
Disease Free

Blood transfusion therapy is often under-utilised in feline practice in South Africa. However, it is a technique that can be safely and effectively introduced in practice. Cats have naturally occurring allo-antibodies against the blood type that they lack, which makes blood typing, or alternatively cross-matching, essential before transfusions. Feline blood donors must be carefully selected, be disease free and should be sedated before blood collection. The preferred anticoagulant for feline blood collection is citrate-phosphatedextrose-adenine. Blood can either be administered intravenously or into the medullary cavity, with the transfusion rate depending on the cat's hydration status and cardiac function. Transfusion reactions can be immediate or delayed and they are classified as immunological or non-immunological. Indications, methods and techniques to do feline blood transfusions in a safe and economical way are highlighted.

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