Search results for " extract"

Behaviour of sediment-associated silver nanoparticles and their toxicity to Lumbriculus variegatus

2017

The increasing use of silver nanoparticles (AgNPs) in industry and consumer products results in the increasing environmental concentrations of AgNPs. In the aquatic environment, sediment is the major sink for the AgNPs. The behaviour and toxicity of AgNPs in sediments is largely unknown, and therefore the potential risk to the benthic ecosystems is difficult to predict. The aim of this thesis was to study the toxicity and uptake of uncoated AgNPs (uc-AgNPs) and polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs) to Lumbriculus variegatus in sediment exposures. Also, the association of AgNP-originated dissolved Ag with sediment components was studied using a sequential extraction method. Studies w…

Improving the Use of Simulation in Nursing Education: Protocol for a Realist Review

2020

BackgroundNursing education has evolved in line with societal needs, and simulation-based learning (SBL) is increasingly being used to bridge the gap between practice and education. Previous literature reviews have demonstrated the effectiveness of using SBL in nursing education. However, there is a need to explore how and why it works to expand the theoretical foundation of SBL.ObjectiveThis review aims to understand how, why, and in what circumstances the use of simulation affects learning as part of the bachelor’s program in nursing.MethodsA realist review will be conducted in accordance with the realist template for a systematic review. In particular, we will identify and explore the un…

Assays for detection of fungal hallucinogens such as psilocybin and psilocin

2016

Methods applicable to the detection of hallucinogenic indole compounds, namely psilocybin, psilocin, and related molecules, that have been developed so far for purposes of mycological research, toxicological studies, or forensic investigations are described in this chapter. The most current literature as well as some interesting older publications are cited, providing a historical overview of the subject. Methods of qualitative and quantitative analysis are presented. Additionally, preliminary purification steps and sample treatment before the exact quantitative determination are proposed. The methods described utilized various analytical techniques for the measurement of psilocybin/psiloci…

Impact of the Extraction Method on the Chemical Composition and Antioxidant Potency of Rosmarinus officinalis L. Extracts

2023

Rosmarinus officinalis L. is a dietary source that produces polyphenols as secondary metabolites. These natural compounds with potent antioxidant abilities are increasingly recommended as a supplement to inhibit oxidative stress. In the current work, we evaluated the impact of the extraction method on the chemical composition of R. officinalis extract, especially on the content of carnosic (CA) and rosmarinic (RA) acids using UPLC-MS-DAD as well as on their antioxidant potency. Four extracts of Tunisian rosemary were obtained from non-conventional extraction techniques:ultrasound-assisted extraction (UAE),supercritical extraction (SFE) and UAE and SFE combined ((UAE-SFE(I), UAE-SFE(II)). Th…

Evaluation of the Behavior of Phenolic Compounds and Steviol Glycosides of Sonicated Strawberry Juice Sweetened with Stevia (Stevia rebaudiana Berton…

2019

In this study, the influence of stevia addition and sonication processing parameters on the phenolic content and profile as well as the steviol glycosides of strawberry juice-based samples was investigated. For this purpose, three matrices&mdash

Supercritical Antisolvent Extraction of Bioactive Compounds from Mango by-Products

2013

Determination of glyphosate and its metabolite aminomethylphosphonic acid in fruit juices using supported-liquid membrane preconcentration method wit…

2005

Abstract The application of supported-liquid membrane (SLM) technique for effective extraction of N -(phosphonomethyl)glycine (glyphosate) and its primary metabolite aminomethylphosphonic acid (AMPA) from juices (orange, grapefruit, apple and blackcurrant) in combination with HPLC-UV detection after derivatization with p -toluenesulphonyl chloride (TsCl) is presented. The influence of various parameters such as the composition of acceptor phase, flow-rate, concentration of analytes, on the performance of extraction procedure, was studied. It was shown that by appropriate manipulation of SLM parameters the level of detection could be significantly improved. The influence of SLM conditions on…

A comparison between two feature selection algorithms

2017

This article provides a comparison of two feature selection algorithms, Information Gain Thresholding and Koller and Sahami's algorithm in the context of text document classification on the Reuters Corpus Volume 1 dataset. The algorithms were evaluated by testing the performance of classifiers trained on the features they select from a given dataset. Results show that Koller and Sahami's algorithm consistently outperforms Information Gain Thresholding by capturing interactions between features and avoiding redundancy among features, although it achieves its gains through increased complexity and longer running time.

A Network-Based Framework for Mobile Threat Detection

2018

Mobile malware attacks increased three folds in the past few years and continued to expand with the growing number of mobile users. Adversary uses a variety of evasion techniques to avoid detection by traditional systems, which increase the diversity of malicious applications. Thus, there is a need for an intelligent system that copes with this issue. This paper proposes a machine learning (ML) based framework to counter rapid evolution of mobile threats. This model is based on flow-based features, that will work on the network side. This model is designed with adversarial input in mind. The model uses 40 timebased network flow features, extracted from the real-time traffic of malicious and…

Support vector machine integrated with game-theoretic approach and genetic algorithm for the detection and classification of malware

2013

Abstract. —In the modern world, a rapid growth of mali- cious software production has become one of the most signifi- cant threats to the network security. Unfortunately, wides pread signature-based anti-malware strategies can not help to de tect malware unseen previously nor deal with code obfuscation te ch- niques employed by malware designers. In our study, the prob lem of malware detection and classification is solved by applyin g a data-mining-based approach that relies on supervised mach ine- learning. Executable files are presented in the form of byte a nd opcode sequences and n-gram models are employed to extract essential features from these sequences. Feature vectors o btained are…