Search results for "Extract"
showing 10 items of 2769 documents
Green synthesis of silver nanoparticles mediated by Pulicaria glutinosa extract
2013
Mujeeb Khan,1 Merajuddin Khan,1 Syed Farooq Adil,1 Muhammad Nawaz Tahir,2 Wolfgang Tremel,2 Hamad Z Alkhathlan,1 Abdulrahman Al-Warthan,1 Mohammed Rafiq H Siddiqui1 1Department of Chemistry, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia; 2Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Mainz, Germany Abstract: The green synthesis of metallic nanoparticles (NPs) has attracted tremendous attention in recent years because these protocols are low cost and more environmentally friendly than standard methods of synthesis. In this article, we report a simple and eco-friendly method for the synthesis of silver NPs using an aqueous…
Bioprospective of Sorbus aucuparia leaf extract in development of silver and gold nanocolloids
2010
At the present time the bioprospective field is a dynamic area of research. The rapid biosynthesis of silver and gold nanoparticles without using toxic chemicals is reported here. Sorbus aucuparia is omnipresent in Europe. The aqueous leaves extract of the plant were used as reducing agent for the synthesis of silver and gold nanoparticles from their salt solutions. The synthesized nanoparticles were spherical, triangular and hexagonal in shape with an average size of 16 and 18nm for silver and gold, respectively. Different extract quantities, metal concentrations, temperatures and contact times were investigated to find their effect on nanoparticles synthesis. The resulting silver and gold…
Protocol for development of various plants leaves extract in single-pot synthesis of metal nanoparticles
2012
This article is aimed to extend a simple protocol for preparation of various plant leaves extract and their application to green synthesis of the metallic nanoparticles. Five plant leaves extract showed mild reduction and stabilization ability for silver and gold nanoparticles (AgNPs and AuNPs) at room temperature. The particle size range varied from 25 to 42 nm and 21 to 47 nm for AgNPs and AuNPs, respectively. Plant leaves extract-mediated nanoparticles were characterized to confirm the shape, size, crystallinity, and content using different spectroscopic investigations. Differences in stability of nanoparticles at different pH were also measured by zeta potential.
A METHOD FOR STUDYING GENETICS OF THE PREDATORY MITE PHYTOSEIULUS PERSIMILIS
2008
Two DNA extraction and purification procedures for single mite analysis, organic (phenol-chloroform) method and the Chelex® -100 DNA extraction procedure, have been compared concerning extraction efficiency, DNA purity and DNA suitability for amplification. Phenol-chloroform extraction takes a relatively long period of time (5 days) and involves the use of toxic and hazardous chemical reagents but it produces consistent results. Chelex is a chelating resin that has a high affinity for polyvalent metal ions, Singer-Sam et al. postulated that boiling a sample in the presence of chelex prevents the degradation of DNA. Both method were evaluated to extract DNA from single frozen mite or individ…
A three-dimensional back-analysis of the collapse of an underground cavity in soft rocks
2017
Abstract The assessment of stability of man-made underground caves, excavated in the past and later on abandoned, represents a serious challenge for land and urban planning operations, especially for the areas of possible interaction of the caves with overlying structures and infrastructures. Several areas of Southern Italy are characterized by the presence of abandoned underground quarries for the extraction of soft calcarenite rocks, which now threatens the overlying environment due to the risk of collapse and the consequent generation of sinkholes. This work presents a back-analysis of a sinkhole occurred in 2011 in the town of Marsala, caused by the collapse of an underground quarry, as…
See how it feels to move: Relationships between movement characteristics and perception of emotions in dance
2020
Music makes humans move in ways found to relate to, for instance, musical characteristics, personality, or emotional content of the music. In this study, we investigated associations between embodiments of musical emotions and the perception thereof. After collecting motion capture data of dancers moving to emotionally distinct musical stimuli, silent stick-figure animations were rated by a set of observers regarding perceived discrete emotions, while 10 movement features were computationally extracted from the motion capture data. Results indicate kinematic profiles—emotion-specific sets of movement characteristics—that furthermore conform with dimensional models of valence and arousal, su…
UBFC-Phys: A Multimodal Database For Psychophysiological Studies of Social Stress
2021
As humans, we experience social stress in countless everyday-life situations. Giving a speech in front of an audience, passing a job interview, and similar experiences all lead us to go through stress states that impact both our psychological and physiological states. Therefore, studying the link between stress and physiological responses had become a critical societal issue, and recently, research in this field has grown in popularity. However, publicly available datasets have limitations. In this article, we propose a new dataset, UBFC-Phys, collected with and without contact from participants living social stress situations. A wristband was used to measure contact blood volume pulse (BVP…
Determination of benzomercaptans in environmental complex samples by combining zeolitic imidazolate framework-8-based solid-phase extraction and high…
2020
[EN] In this work, the synthesis of zeolitic imidazolate framework-8 (ZIF-8) crystals and their subsequent application as effective sorbents for extraction and preconcentration of several benzomercaptans from environmental complex samples is described. These materials were prepared by solvothermal approach varying the concentration of n-butylamine modulator to modify the surface of the metal-organic framework. The resulting materials were characterized by scanning and transmission electron microscopy, powder X-ray diffraction and Fourier transform infrared spectroscopy. The ZIF-8 material that gave the best features was selected as extractive phase and the influence of various parameters (s…
Volatile profiles of Sicilian prickly pear (Opuntia ficus indica) by SPME-GC/MS analysis
2005
The aroma compounds present in the headspace of homogenized slurries of fresh prickly pears (Opuntia ficus-indica) from Sicilian cultivars were determined. Solid Phase Microextraction (SPME) followed by Gas-chromatography/Mass Spectrometry (GC/MS) analysis was used to characterize the volatile compounds. The volatile flavour profiles of the three cultivars investigated (red, white and yellow) showed significant differences. The aromatic profile of peeled prickly pears stored for one day was different from the one of the fresh samples, mainly due to the occurrence of some oxidative and hydrolytic reactions
Determination of phenolic compounds in surface waters using high-performance liquid chromatography and molecularly imprinted solid-phase extraction
2021
An effective and reliable analytical method based on molecularly imprinted solid-phase extraction (MI-SPE) and high-performance liquid chromatography with photodiode array detector was developed to simultaneously determine four phenolic compounds: bisphenol A, 2-phenylphenol, tert-octylphenol and nonylphenol. A molecularly imprinted polymer that can selectively recognize bisphenol A and alkylphenols was developed. A bulk polymerization method using bisphenol A as a template, acrylamide as functional monomer, ethylene glycol dimethacrylate as the cross-linking agent, acetonitrile as porogenic solvent and 1,1’-azobis(cyclohexanecarbonitrile) as initiator was applied. This polymer was applied …