scholarly journals Considerations for and Guidance to Testing and Evaluating Migration/Release of Nanoparticles from Polymer Based Nanocomposites

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1113 ◽  
Author(s):  
Roland Franz ◽  
Johannes Bott ◽  
Angela Störmer

The use of nanoadditives in food contact materials requires risk assessment to ensure consumers’ safety. The evaluation of health risk is based on the combination of two elements: hazard and exposure. For nanomaterials (NM) used as additives in nanocomposites, the exposure is directly linked to the level of migration or release of the NM into the food. In principle, appropriate methods for experimental determination and theoretical estimation of migration are available but need diligent considerations to avoid erroneous conclusions from the measured data. We propose a comprehensive test scheme based on these methods, starting with characterization of the nanomaterial itself and when incorporated in the polymer. These data form the basis for making a decision whether migration of the NM can be excluded by migration theoretical considerations or if experimental migration testing and/or abrasion testing for mechanical release should be carried out. Guidance to and considerations for each of these steps and regarding the applicable methods are discussed. In conclusion, the results will provide a basis for risk assessment, either directly when exposure of consumers to the nanomaterials can be excluded or will be very low or, in the case of evidenced exposure, in combination with then needed toxicological data.

2021 ◽  
Vol 11 (9) ◽  
pp. 3789
Author(s):  
Emmanouil D. Tsochatzis ◽  
Georgios Theodoridis ◽  
Helen G. Gika

Nuclear clarifying agents (NCAs) are a class of substances frequently used as additives in the production of polymers to improve their physical properties. Some are EU regulated under Commission Regulation (EU) no. 10/2011 can be used as additives in the production of food contact plastics. However, limited analytical methods for their analysis are currently available, in part due to poor solubility in most common organic solvents and lack of analytical standards of known purity. In this work, a simple and sensitive method was developed to analyze 4 EU-regulated sorbitol-based nucleating agents in food simulants, following solubility studies to establish effective solvents. The method was shown to be accurate and precise and can be used with official food simulant D1 (50% v/v ethanol/H2O). Application to other ethanolic simulants is also possible, but due to solubility issues, a posteriori conversion of those simulants into simulant D1 is required. Finally, the method was applied to quantify the target analytes in simulants after migration testing with polypropylene (PP) beverage cups.


Author(s):  
David Song ◽  
Ashish Gupta ◽  
Chia-Pin Chiu

This paper presents the current-carrying-capacity (CCC) characterization of a land-grid-array type microprocessor socket. This CCC study has been performed using both computational modeling and experiments using infrared camera. A subsequent risk assessment was performed against the maximum allowed temperature at the point of pressure contact of socket pin for the use-condition socket pin current and motherboard temperature. The results from the modeling and the experimental results are compared.


Author(s):  
Hui‐Lin Chin ◽  
Kieran O'Neill ◽  
Kristal Louie ◽  
Lindsay Brown ◽  
Kamilla Schlade‐Bartusiak ◽  
...  

Author(s):  
O Morales-Nápoles ◽  
D Worm ◽  
L Abspoel-Bukman ◽  
J Huibregtse ◽  
W Courage
Keyword(s):  

Nativa ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 219
Author(s):  
Jania Claudia Camilo dos Santos ◽  
Dayane Mércia Ribeiro Silva ◽  
Renato Nunes Costa ◽  
Carlos Humberto Da Silva ◽  
Wilton Da Silva Santos ◽  
...  

O objetivo deste trabalho foi avaliar a biometria e morfologia de S. brasiliensis, visando identificar características que auxiliem no uso e propagação dessa espécie da Caatinga em programa de restauração ambiental. Os dados biométricos foram obtidos a partir de 1000 frutos e 1000 sementes. Foram medidos o comprimento, largura, espessura e massa de frutos e sementes. Os dados foram ajustados utilizando a estatística descritiva e teste de Shapiro-Wilk. Para a descrição morfológica dos frutos, foram relatadas observações sobre os aspectos externos e internos do pericarpo, consistência da casca, coloração, brilho, forma e deiscência. Já as descrições morfológicas externa das sementes foram feitas observações sobre consistência, coloração, textura, forma e hilo. A caracterização biométrica de frutos e sementes de S. brasiliensis, possibilitou verificar a variação existente entre as classes biométricas através de histograma de frequência. Os frutos apresentam morfologia completa, em forma de sâmara, indeiscente e monospérmico. As sementes foram caracterizadas em oblongas e reniformes, envolvidas pelo endocarpo, resultando no pirênio, sendo esta a camada que dificulta o processo de embebição de água, a qual antecede a germinação, no entanto, esta camada é capaz de promover maior longevidade as sementes.Palavras-chave: análises biométricas, características morfológicas, sementes florestais, Caatinga. BIOMETRIC AND MORPHOLOGICAL ASPECTS OF THE FRUITS AND SEEDS OF SCHINOPSIS BRASILIENSIS ABSTRACT:The objective of this work was to evaluate the biometry and morphology of S. brasiliensis, aiming to identify traits that help in the use and propagation of this Caatinga species in an environmental restoration program. Biometric data were obtained from 1000 fruits and 1000 seeds. The length, width, thickness and mass of fruits and seeds were measured. Data were adjusted using descriptive statistics and Shapiro-Wilk test. For the fruits morphological description, observations on the external and internal traits of the pericarp, peel consistency, coloration, brightness, shape and dehiscence were reported. Already the external morphological descriptions of the seeds were made on consistency, color, texture, shape and thread. The biometric characterization of fruits and seeds of S. brasiliensis made it possible to verify the variation between the biometric classes through frequency histogram. The fruits presented complete morphology, in the form of a samara, indiscriminate and monospermic. The seeds were characterized in oblong and reniform, surrounded by the endocarp, resulting in the pyrenium, which is the layer that hinders the process of water imbibition, which precedes the germination, however this layer is able to promote greater longevity of the seeds.Keywords: biometric analyzes, morphological traits, forest seeds, Caatinga. DOI:


2021 ◽  
Vol 2 (Supplement_1) ◽  
pp. A46-A46
Author(s):  
D Levendowski ◽  
J Lee-Iannotti ◽  
D Shprecher ◽  
C Guevarra ◽  
P Timm ◽  
...  

Abstract Purpose Compare agreements between polysomnography-based (PSG) diagnosis of isolated REM-sleep-behavior-disorder (iRBD) and Non-REM-Hypertonia (NRH), a novel biomarker independently associated with synucleinopathy-related neurodegenerative diseases. Methods Sixteen patients with histories of dream-enactment-behavior (DEB)(women=38%; age:64.6±13.0) underwent PSG with simultaneously-recorded Sleep Profiler (SP). Two boarded sleep neurologists independently characterized iRBD. Physician1 combined abnormal qualitative REM-sleep-without-atonia (RSWA) by submental electromyography, with video-confirmation of probably DEB. Physician2 relied solely on qualitative RSWA. SP was auto-staged, technically reviewed, and reprocessed for automated abnormal NRH detection. Kappa scores measured physician and NRH agreements. Results In the 14 records with REM sleep, iRBD was characterized in: Physician1=64%, Physician2=79%, NRH=71% of the records. Across the three methods, unanimous iRBD agreement occurred in 57% of the records (positive=7, negative=1). The between-physician agreement in iRBD classifications was fair (kappa=0.32). The agreement between NRH and Physician1 was moderate (kappa=0.52) versus slight with Physician2 (kappa=0.05). NRH comparisons to consensus physician agreement yielded one false-positive and one false-negative iRBD finding. Physician2 classified: a) iRBD in two cases that were negative by Physician1 and NRH, and b) one negative case that Physician1 and NRH characterized as iRBD. Physician1 identified one negative case that was classified iRBD by Physician2 and NRH. Additionally, NRH was abnormal in one of the two records with no REM sleep. Discussion NRH may assist in iRBD risk assessment, given it agreed with at least one physician in 86% of the cases and the between-physician iRBD agreement was only fair. NRH also characterized iRBD-risk in patients with insufficient REM sleep for RSWA assessment.


2006 ◽  
Vol 2006 (2) ◽  
pp. 23-30 ◽  
Author(s):  
V.V. Kirsenko ◽  
◽  
T.A. Yastrub ◽  
V.F. Kovalenko ◽  
M.L. Marchenko ◽  
...  

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