Occurrence of neonicotinoids in guttation liquid of maize – soil mobility and cross-contamination

2017 ◽  
Vol 97 (9) ◽  
pp. 868-884 ◽  
Author(s):  
Mária Mörtl ◽  
Béla Darvas ◽  
Ágnes Vehovszky ◽  
János Győri ◽  
András Székács
Keyword(s):  
Cross Contamination ◽  
Soil Mobility

Restorative dental treatment in times of COVID-19

2020 ◽  
Vol 68 ◽  
Author(s):  
Robson de Lima GOMES ◽  
Marlus da Silva PEDROSA ◽  
Claudio Heliomar Vicente da SILVA
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Dental Treatment ◽  
Close Contact ◽  
Cross Contamination ◽  
Clinical Protocols ◽  
Know How ◽  
Dental Procedures ◽  
Dental Staff ◽  
Dental Professional ◽  
Restrictive Measures

ABSTRACT Since the outbreak of the Coronavirus Disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), numerous restrictive measures have been adopted by governments of different countries. The return to elective dental care in Brazil is a reality even during the COVID-19 pandemic. During restorative dental procedures, the dental professional requires close contact with the patient, being exposed to contaminated saliva and fluids. In addition, transmission of COVID-19 by the generation of aerosol produced by dental handipieces may be possible. Thus, the dental staff must know how to act during restorative dental procedures, putting into practice the correct clinical protocols to avoid cross-contamination and COVID-19 spread. The purpose of this article is to review the literature on the biosafety practices especially in the context of restorative dental procedures in times of COVID-19.

An Effective SIMS Methodology for GOI Contamination Analysis

2013 ◽  
Author(s):  
Yanhua Huang ◽  
Lei Zhu ◽  
Kenny Ong ◽  
Hanwei Teo ◽  
Younan Hua
Keyword(s):  
Oxide Layer ◽  
Secondary Ion Mass Spectrometry ◽  
Gate Oxide ◽  
Sample Surface ◽  
Low Energy ◽  
Cross Contamination ◽  
Common Effect ◽  
Sims Analysis ◽  
Secondary Ion ◽  
Lower Background

Abstract Contamination in the gate oxide layer is the most common effect which cause the gate oxide integrate (GOI) issue. Dynamic Secondary Ion Mass Spectrometry (SIMS) is a mature tool for GOI contamination analysis. During the sample preparation, all metal and IDL layers above poly should be removed because the presence of these layers added complexity for the subsequent SIMS analysis. The normal delayering process is simply carried out by soaking the sample in the HF solution. However, the poly surface is inevitably contaminated by surroundings even though it is already a practice to clean with DI rinse and tape. In this article, TOFSIMS with low energy sputter gun is used to clean the sample surface after the normal delayering process. The residue signals also can be monitored by TOF SIMS during sputtering to confirm the cross contamination is cleared. After that, a much lower background desirable by dynamic SIMS. Thus an accurate depth profile in gate oxide layer can be achieved without the interference from surface.

An artificial intelligent platform for live cell identification and the detection of cross-contamination (Preprint)

2019 ◽  
Author(s):  
Ruixin Wang ◽  
Dongni Wang ◽  
Dekai Kang ◽  
Xusen Guo ◽  
Chong Guo ◽  
...  
Keyword(s):  
Single Cell ◽  
Cell Line ◽  
Cell Lines ◽  
Cell Morphology ◽  
Single Cell Level ◽  
Cross Contamination ◽  
Cell Level ◽  
Cell Identification ◽  
Pure Cell ◽  
Microscopy Images

BACKGROUND In vitro human cell line models have been widely used for biomedical research to predict clinical response, identify novel mechanisms and drug response. However, one-fifth to one-third of cell lines have been cross-contaminated, which can seriously result in invalidated experimental results, unusable therapeutic products and waste of research funding. Cell line misidentification and cross-contamination may occur at any time, but authenticating cell lines is infrequent performed because the recommended genetic approaches are usually require extensive expertise and may take a few days. Conversely, the observation of live-cell morphology is a direct and real-time technique. OBJECTIVE The purpose of this study was to construct a novel computer vision technology based on deep convolutional neural networks (CNN) for “cell face” recognition. This was aimed to improve cell identification efficiency and reduce the occurrence of cell-line cross contamination. METHODS Unstained optical microscopy images of cell lines were obtained for model training (about 334 thousand patch images), and testing (about 153 thousand patch images). The AI system first trained to recognize the pure cell morphology. In order to find the most appropriate CNN model，we explored the key image features in cell morphology classification tasks using the classical CNN model-Alexnet. After that, a preferred fine-grained recognition model BCNN was used for the cell type identification (seven classifications). Next, we simulated the situation of cell cross-contamination and mixed the cells in pairs at different ratios. The detection of the cross-contamination was divided into two levels, whether the cells are mixed and what the contaminating cell is. The specificity, sensitivity, and accuracy of the model were tested separately by external validation. Finally, the segmentation model DialedNet was used to present the classification results at the single cell level. RESULTS The cell texture and density were the influencing factors that can be better recognized by the bilinear convolutional neural network (BCNN) comparing to AlexNet. The BCNN achieved 99.5% accuracy in identifying seven pure cell lines and 86.3% accuracy for detecting cross-contamination (mixing two of the seven cell lines). DilatedNet was applied to the semantic segment for analyzing in single-cell level and achieved an accuracy of 98.2%. CONCLUSIONS This study successfully demonstrated that cell lines can be morphologically identified using deep learning models. Only light-microscopy images and no reagents are required, enabling most labs to routinely perform cell identification tests.

scholarly journals OCORRÊNCIA DO HERBICIDA TEBUTHIURON NA ÁGUA SUBTERRÂNEA DA MICROBACIA DO CÓRREGO ESPRAIADO, RIBEIRÃO PRETO - SP

2001 ◽  
Vol 11 ◽  
Author(s):  
MARCO ANTONIO FERREIRA GOMES ◽  
CLÁUDIO A. SPADOTTO ◽  
VERA LÚCIA LANCHOTTE
Keyword(s):  
Biological Activity ◽  
Low Temperature ◽  
Water Samples ◽  
Critical Level ◽  
World Health ◽  
Contamination Risk ◽  
Soil Mobility ◽  
Drinkable Water ◽  
Health Organization ◽  
Monitoring Area

Pretendeu-se mostrar que o herbicida Tebuthiuron, selecionado entre outros usados na cultura de cana-de-açúcar, oferece risco de contaminação para a água subterrânea em função de suas características físico-químicas, principalmente, quando aplicado em áreas de recarga direta de aqüíferos consideradas de alta vulnerabilidade natural. Assim, efetuou-se monitoramento do referido herbicida no período compreendido entre 1995 e 1999, coletando amostras de água de poço semi-artesiano, com 53 metros de profundidade, localizado na microbacia do Córrego Espraiado, município de Ribeirão Preto/SP, Brasil, no qual tem sido freqüente o uso do produto em questão. Para efeito de testemunha da amostra de água foi considerado um poço semi-artesiano de profundidade semelhante, localizado cerca de três quilômetros de distância do poço objeto de monitoramento. Os resultados obtidos mostraram que o Tebuthiuron está presente em todas as amostras analisadas, embora em concentrações abaixo do nível crítico para padrão de potabilidade, conforme os limites mais restritivos estabelecidos pela Organização Mundial de Saúde (para os pesticidas em uso é de 0,1 µg/L por pesticida e de 0,5 µg/L para pesticidas totais). Mesmo com os baixos valores de concentração encontrados fica evidente que o Tebuthiuron está atingindo a água subterrânea podendo aumentar sua concentração pela existência de condições ambientais favoráveis à preservação da molécula em profundidade (tais como baixa temperatura, baixa atividade biológica e ausência de luz). Caso o nível crítico seja atingido, o risco de contaminação poderia ser minimizado por meio da substituição do Tebuthiuron por outro herbicida com menor mobilidade no perfil do solo. OCCURRENCE OF THE HERBICIDE TEBUTHIURON IN GROUNDWATER OF ESPRAIADO CATCHMENT RIBEIRAO PRETO - SP (BRASIL) Abstract The herbicide Tebuthiuron, selected among others utilized in sugar-cane crop, shows groundwater contamination risk due to its physicochemical properties, mainly, when applied in direct recharge areas of aquifers considered of high natural vulnerability. In this context, the monitoring of this herbicide in the period of 1995 through 1999 was realized, by collecting water samples of aquifers 53 m depht, located in Espraiado catchment, Ribeirao Preto/SP (Brazil) in which the product has been extensively used. For blank assays it was utilized water samples collected similarly 3 Km away from the monitoring area. The results obtained showed that Tebuthiuron is present in all analyzed samples. Although in lower concentrations of the critical level for drinkable water, following the restrictive limits established by World Health Organization (for pesticides in use is 0,1 µg/L by pesticide and of 0,5 µg/L for total pesticides). Even if the low concentration values found it is evident that the Tebuthiuron affects the groundwater, and could enhance its concentration by favorable ambiental conditions for molecule preservation in deep water (such as low temperature, low biological activity and absence of light). The present scenary reflects contamination risk in case of reaching the critical level, which could only be minimized by the substitution of Thebuthiuron for other herbicide with lower soil mobility.

Determination of Dimetridazole and Ipronidazole in Feeds at Cross-Contamination Levels

1988 ◽  
Vol 71 (3) ◽  
pp. 474-477 ◽  
Author(s):  
Duane D Hughes
Keyword(s):  
Thin Layer ◽  
Rapid Method ◽  
Aqueous Phase ◽  
Borate Buffer ◽  
Cross Contamination ◽  
Chromatographic System ◽  
Arsanilic Acid ◽  
Contamination Levels ◽  
Benzene Extract

Abstract A rapid method for the determination of dimetridazole and ipronidazole in feeds is described. The compounds are extracted from a borate buffer (pH 8.65) with benzene, partitioned into IN HC1, and then partitioned back into benzene from a basic aqueous phase. The benzene extract is concentrated and injected onto a nonpolar (Apiezon L) gas chromatographic column for determination by 63Ni electroncapture detection. Recoveries from feeds of various composition, spiked at 0.2 ppm with both dimetridazole and ipronidazole, ranged from 70 to 115%; for the same feeds spiked at 1 ppm or more, the recoveries were greater than 80%. Carbadox, furazolidone, levamisole, oxytetracycline, chlortetracycline, sulfamethazine, sulfaquinoxaline, arsanilic acid, piperazine, penicillin, and commonly added vitamins and minerals do not interfere. A 2-dimensional thin layer chromatographic system is presented as a means of additional identification.

scholarly journals Hepatitis E Virus RNA Presence in Wild Boar Carcasses at Slaughterhouses in Italy

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1624
Author(s):  
Mario Forzan ◽  
Maria Irene Pacini ◽  
Marcello Periccioli ◽  
Maurizio Mazzei
Keyword(s):  
Wild Boar ◽  
Hepatitis E Virus ◽  
Foodborne Pathogen ◽  
Hepatitis E ◽  
Cross Contamination ◽  
Wild Animals ◽  
Prevalence Rates ◽  
Virus Rna ◽  
The World ◽  
Undercooked Meat

Hepatitis E virus (HEV) is a waterborne and foodborne pathogen largely spread around the world. HEV is responsible for acute hepatitis in humans and it is also diffused in domestic and wild animals. In particular, domestic pigs represent the main reservoir of the infection and particular attention should be paid to the consumption of raw and undercooked meat as a possible zoonotic vehicle of the pathogen. Several studies have reported the presence of HEV in wild boar circulating in European countries with similar prevalence rates. In this study, we evaluated the occurrence of HEV in wild boar hunted in specific areas of Tuscany. Sampling was performed by collecting liver samples and also by swabbing the carcasses at the slaughterhouses following hunting activities. Our data indicated that 8/67 (12%) of liver samples and 4/67 (6%) of swabs were positive for HEV RNA. The presence of HEV genome on swabs indicates the possible cross-contamination of carcass surfaces during slaughtering procedures. Altogether, our data indicated that it is essential to promote health education programmes for hunters and consumers to limit the diffusion of the pathogen to humans.

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