Magnetic study of Fe3O4/Ag nanoparticles

2018 ◽  
Vol 83 (1) ◽  
pp. 10402
Author(s):  
Janusz Typek ◽  
Nikos Guskos ◽  
Grzegorz Zolnierkiewicz ◽  
Zofia Lendzion-Bielun ◽  
Anna Pachla ◽  
...  
Keyword(s):  
Antibacterial Properties ◽  
Blocking Temperature ◽  
Precipitation Method ◽  
Magnetic Clusters ◽  
Mass Ratio ◽  
Three Samples ◽  
Two Samples ◽  
Magnetic Resonance Technique ◽  
Silver Nps ◽  
Multi Mode

Nanocomposites of Fe3O4 nanoparticles (NPs) impregnated with silver NPs display antibacterial properties and may be used in water treatment as disinfection agent. Three samples were synthesized: Fe3O4 NPs obtained by the precipitation method and additionally two samples with added silver NPs with mass ratio of Ag:Fe3O4 equal to 1:100 and 2:100. Magnetic properties of these samples were studied by SQUID magnetometry (in temperature range 2–300 K and magnetic fields up to 70 kG) and magnetic resonance technique at RT. Temperature dependence of dc susceptibility revealed the blocking temperature close to RT in all three samples and allowed to determine the presence of single or multi-mode distribution of NP sizes in a particular sample. Isothermal magnetisation measurements showed that the presence of silver NPs, especially those with smaller sizes, decreases the saturation magnetisation. The shape of ferromagnetic loop registered at T = 2 K was used to discuss the sizes of NP magnetic clusters in our samples. Conclusions obtained from analysis of the ferromagnetic resonance spectra were consistent with the propositions based on the magnetometric studies.

scholarly journals Microbiological analysis for drug resistant pathogenic microorganisms with determination of the antibacterial properties found in Fragaria x ananassa (strawberry) samples

2017 ◽  
Vol 6 (1) ◽  
pp. 16-19
Author(s):  
Nazneen Piangka ◽  
Tasnia Ahmed ◽  
Mrityunjoy Acharjee
Keyword(s):  
Pathogenic Bacteria ◽  
Antibacterial Properties ◽  
Microbiological Analysis ◽  
Drug Resistant ◽  
E Coli ◽  
Three Samples ◽  
Wide Range ◽  
Two Samples ◽  
Health Related

Strawberry is a popular fruit item consumed by people all over the world for its exceptional flavor and aroma. This fruit is being used to prepare a wide range of food items. Strawberries when consumed by people without undergoing any processing, the condition may not be good enough. People may get sick after consuming raw strawberries. Our current study identified several pathogenic bacteria which are very known in causing health related problems. E. coli was found in one sample (1.0×102 cfu/g), Staphylococcus aureus was commonly present in all of the five samples (up to 1.2×106 cfu/g), Klebsiella spp. was found to be present in two samples (within 1.0×103 cfu/g) and Pseudomonas spp. was present in three samples (8.2×104 cfu/g), respectively. All isolated bacteria showed some degree of drug resistant traits against some commonly used antibiotics. The most important and promising part of the study was to successfully find the antimicrobial activity of strawberries against seven types of pathogenic bacteriaStamford Journal of Microbiology, Vol.6(1) 2016: 16-19

scholarly journals Biosystematic Study on Some Egyptian Species of Astragalus L. (Fabaceae)

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 125
Author(s):  
Monier M. Abd El-Ghani ◽  
Ashraf S. A. El-Sayed ◽  
Ahmed Moubarak ◽  
Rabab Rashad ◽  
Hala Nosier ◽  
...  
Keyword(s):  
Genetic Relationships ◽  
Dna Barcode ◽  
Plant Morphology ◽  
Its Region ◽  
Its2 Region ◽  
Whole Plant ◽  
Three Samples ◽  
Two Samples ◽  
Region 10 ◽  
Unique Banding Pattern

Astragalus L. is one of the largest angiosperm complex genera that belongs to the family Fabaceae, subfamily Papilionoideae or Faboideae under the subtribe Astragalinae of the tribe Galegeae. The current study includes the whole plant morphology, DNA barcode (ITS2), and molecular marker (SCoT). Ten taxa representing four species of Astragalus were collected from different localities in Egypt during the period from February 2018 to May 2019. Morphologically, identification and classification of collected Astragalus plants occurred by utilizing the light microscope, regarding the taxonomic revisions of the reference collected Astragalus specimens in other Egyptian Herbaria. For molecular validation, ten SCoT primers were used in this study, producing a unique banding pattern to differentiate between ten samples of Astragalus taxa which generated 212 DNA fragments with an average of 12.2 bands per 10 Astragalus samples, with 8 to 37 fragments per primer. The 212 fragments amplified were distributed as 2 monomorphic bands, 27 polymorphic without unique bands, 183 unique bands (210 Polymorphic with unique bands), and ITS2 gene sequence was showed as the optimal barcode for identifying Astragalus L. using BLAST searched on NCBI database, and afterward, analyzing the chromatogram for ITS region, 10 samples have been identified as two samples representing A. hauarensis, four samples representing A. sieberi, three samples representing A. spinosus and one sample representing A. vogelii. Based on the ITS barcode, A. hauarensis RMG1, A. hauarensis RMG2, A. sieberi RMG1, A. sieberi RMG2, A. sieberi RMG3, A. sieberi RMG4, A. spinosus RMG1, A. spinosus RMG2, A. spinosus RMG3, A. vogelii RMG were deposited into GenBank with accession # MT367587.1, MT367591.1, MT367593.1, MT367585.1, MT367586.1, MT367588.1, MT160347.1, MT367590.1, MT367589.1, MT367592.1, respectively. These results indicated the efficiency of SCoT markers and ITS2 region in identifying and determining genetic relationships between Astragalus species.

scholarly journals A Comparison of the Composition of Selected Commercial Sandalwood Oils with the International Standard

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2249
Author(s):  
Malgorzata Kucharska ◽  
Barbara Frydrych ◽  
Wiktor Wesolowski ◽  
Jadwiga A. Szymanska ◽  
Anna Kilanowicz
Keyword(s):  
Mass Spectrometry Analysis ◽  
Santalum Album ◽  
Benzyl Benzoate ◽  
Spectrometry Analysis ◽  
Correct Information ◽  
Three Samples ◽  
Two Samples ◽  
High Street ◽  
Chromatographic Profile ◽  
Sandalwood Oil

Sandalwood oils are highly desired but expensive, and hence many counterfeit oils are sold in high street shops. The study aimed to determine the content of oils sold under the name sandalwood oil and then compare their chromatographic profile and α- and β santalol content with the requirements of ISO 3518:2002. Gas chromatography with mass spectrometry analysis found that none of the six tested “sandalwood” oils met the ISO standard, especially in terms of α-santalol content. Only one sample was found to contain both α- and β-santalol, characteristic of Santalum album. In three samples, valerianol, elemol, eudesmol isomers, and caryophyllene dominated, indicating the presence of Amyris balsamifera oil. Another two oil samples were found to be synthetic mixtures: benzyl benzoate predominating in one, and synthetic alcohols, such as javanol, polysantol and ebanol, in the other. The product label only gave correct information in three cases: one sample containing Santalum album oil and two samples containing Amyris balsamifera oil. The synthetic samples described as 100% natural essential oil from sandalwood are particularly dangerous and misleading to the consumer. Moreover, the toxicological properties of javanol, polysantol and ebanol, for example, are unknown.

scholarly journals Influence of pH on Structural, Morphological, Optical, Photocatalytic, and Antibacterial Properties of Yttrium Oxide Nanoparticles via Co-Precipitation Method

2021 ◽  
Author(s):  
Kiruthika Parangusan ◽  
Venkat Subramanium ◽  
Lakshmanaperumal Sundarabharathi ◽  
Karthik Kannan ◽  
Devi Radhika
Keyword(s):  
Yttrium Oxide ◽  
Antibacterial Properties ◽  
Blue Emission ◽  
Precipitation Method ◽  
Diffusion Method ◽  
Bandgap Energy ◽  
Oxide Nanoparticles ◽  
Ph Values ◽  
Co Precipitation ◽  
Yttrium Oxide Nanoparticles

Abstract Yttrium oxide nanoparticles with multiform morphologies have been synthesized by the co-precipitation method. The structure, morphology, functional groups, optical and photoluminescence properties were examined through X-ray diffraction (XRD), Scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), UV-Visible (UV-Vis), Photoluminescence spectra (PL). The XRD patterns obtained for the samples synthesized at various pH values confirmed the cubic structure of Y2O3. The patterns obtained on the samples at pH values of 8 and 9 appeared as have sharp peaks suggested, that the samples were well crystallized. From UV-vis spectra, it revealed that the bandgap energy exhibits a blue shift in the absorption edge for the samples with the increase of pH due to their changing morphologies and surface structures. In the PL spectra, the obtained Y2O3 samples demonstrate an intense and bright UV and blue emission under the excitation wavelength range of 250 nm. The photocatalytic degradation of the Y2O3 nanostructure was studied against the Methylene blue (MB) dye under sunlight irradiation. The results showed good recital under solar light irradiation. Further, the antimicrobial activities of Y2O3 nanostructure against foodborne pathogens (Staphylococcus aureus and Salmonella typhi) were examined by using the disc diffusion method. Moreover, the Y2O3 nanostructure was found to be biocompatible.

scholarly journals The Effect of Weathering on Salt Release from Coal Mine Spoils

Minerals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 760
Author(s):  
Melinda Hilton ◽  
Mandana Shaygan ◽  
Neil McIntyre ◽  
Thomas Baumgartl ◽  
Mansour Edraki
Keyword(s):  
Particle Size ◽  
Coal Mine ◽  
Chemical Weathering ◽  
Physical Weathering ◽  
Particle Size Fractions ◽  
Mine Spoils ◽  
Weathering Processes ◽  
Three Samples ◽  
Two Samples ◽  
Physical And Chemical

Coal mine spoils have the potential to create environmental impacts, such as salt load to surrounding environments, particularly when exposed to weathering processes. This study was conducted to understand the effect of physical and chemical weathering on the magnitude, rate, and dynamics of salt release from different coal mine spoils. Five spoil samples from three mines in Queensland were sieved to three different particle size fractions (<2 mm, 2–6 mm, and >6 mm). Two samples were dispersive spoils, and three samples were nondispersive spoils. The spoils were subjected to seven wet–dry cycles, where the samples were periodically leached with deionised water. The rate, magnitude, and dynamics of solutes released from spoils were spoil specific. One set of spoils did not show any evidence of weathering, but initially had higher accumulation of salts. In contrast, broad oxidative weathering occurred in another set of spoils; this led to acid generation and resulted in physical weathering, promoting adsorption–desorption and dissolution and, thus, a greater release of salts. This study indicated that the rate and magnitude of salt release decreased with increasing particle size. Nevertheless, when the spoil is dispersive, the degree of weathering manages salt release irrespective of initial particle size. This study revealed that the long-term salt release from spoils is not only governed by geochemistry, weathering degree, and particle size but also controlled by the water/rock ratio and hydrological conditions of spoils.

scholarly journals A Study of the Micropore Structure of Carbonized Rayon Yarn by Nitrogen Adsorption and Nonane Pre-Adsorption

1985 ◽  
Vol 2 (2) ◽  
pp. 89-95 ◽  
Author(s):  
J. N. Bohra ◽  
K. S. W. Sing
Keyword(s):  
External Surface ◽  
Nitrogen Adsorption ◽  
The Other ◽  
Adsorption Method ◽  
Micropore Structure ◽  
Surface Areas ◽  
Three Samples ◽  
Two Samples ◽  
Before And After ◽  
Gain Access

Adsorption isotherms of nitrogen have been determined at 77 K on three samples of carbonized rayon yarn, both before and after the pre-adsorption of n-nonane. In their original state the three samples were all highly microporous. Application of the αs-method of isotherm analysis reveals that their micropore volumes were 0·17–0·19 cm3g−1 and their external surface areas 20–27 m2g−1 (the corresponding BET areas being 427–483 m2g−1). Nonane pre-adsorption resulted in blockage of the entire micropore structure only in the case of one sample: micropore volumes ∼0·1 cm3g−1 were still available for nitrogen adsorption in the other two samples. It appears that nitrogen molecules were able to gain access to some parts of these micropore structures through wider pore entrances which were not completely blocked by the pre-adsorbed nonane. The work has shown that the nonane pre-adsorption method requires further investigation before it can be used with confidence for the assessment of microporosity.

An in situ study of the phase transitions among CaCO3 high-pressure polymorphs

2018 ◽  
Vol 83 (02) ◽  
pp. 191-197 ◽  
Author(s):  
Xueyin Yuan ◽  
Chao Gao ◽  
Jing Gao
Keyword(s):  
Phase Transitions ◽  
Intermediate Phase ◽  
The Other ◽  
Three Samples ◽  
Short Period ◽  
Two Samples ◽  
Wide Pressure Range ◽  
Diamond Anvil ◽  
Wide Pressure

AbstractThe phase transitions involving calcite (CaCO3-I), CaCO3-II, CaCO3-III and CaCO3-IIIb were investigated using a diamond anvil cell and micro-Raman spectroscopy. Based on the results obtained from in situ observations and Raman measurements made with six natural calcite crystals, the phase transition from calcite to CaCO3-II took place between 1.56 and 1.67 GPa under ambient temperature. Under a precise pressure of 1.97 ± 0.03 GPa, three CaCO3 samples were observed to transform from CaCO3-II directly to CaCO3-III, while in the other three samples both CaCO3-III and CaCO3-IIIb crystal structures were detected. Transformation from CaCO3-IIIb to CaCO3-III was completed in a short period in one sample, whereas in the other two samples coexistence of CaCO3-III and CaCO3-IIIb was observed over a wide pressure range from 1.97 to 3.38 GPa, with sluggish transformation from CaCO3-IIIb to CaCO3-III being observed after the samples were preserved under 3.38 GPa for 72 h. Hence, it can be concluded that CaCO3-IIIb is a metastable intermediate phase occurring during the reconstructive transformation from CaCO3-II to CaCO3-III. Splitting of the C–O in-plane bending (ν4) and symmetric stretching (ν1) vibrations and appearance of new lattice vibrations in the Raman spectra of CaCO3-III and CaCO3-IIIb suggest a lowering in crystal symmetry during the transformation from CaCO3-II through CaCO3-IIIb to CaCO3-III, which is in good agreement with the observed sequence of phase symmetries.

Determination of Heavy Metals in Wheat and Barley Grains Using ICP-MS/MS

2020 ◽  
Vol 103 (5) ◽  
pp. 1277-1281
Author(s):  
Tamer M A M Thabit ◽  
Shokr Abdelsalam Shokr ◽  
Dalia I H Elgeddawy ◽  
Medhat A H El-Naggar
Keyword(s):  
Heavy Metals ◽  
Acid Digestion ◽  
Validation And Verification ◽  
European Origin ◽  
Three Samples ◽  
Icp Ms ◽  
Two Samples ◽  
Low Levels ◽  
Barley Grains

Abstract Wheat and barley grains are two of the most important nutritional grains for humans and animals and they play an essential role in the nutritional cycle by different ratios according to people's nutritional habits. This work aimed to monitor ten of the most important heavy metals in some European-origin wheat and barley grains during the season of 2018. The measured elements, Al, As, Cd, Co, Cr, Hg, Mo, Ni, Pb, and V, are of importance ecologically and biologically and may be involved in many health disorders affecting the human body. Moisture, protein, and specific grain weights were checked. Samples were digested using microwave acid digestion and the elements measured with ICP-MS/MS in He mode to increase sensitivity, lower the background, and avoid interference. Method validation and verification were carried out through spiking at two levels (2.0 and 10 ppb), then RSD, LOD, and LOQ were calculated. Recoveries were &gt;97% for all elements at both levels with an RSD of &lt;7.6%. Results revealed that As, Cd, Hg, and Pb were not detected in most wheat and barley samples, whereas Cd was detected in one sample of Ukrainian wheat and two samples of Estonian barley (but in very small traces). Pb was detected in three samples of Polish wheat (in very small traces). Al, Mo, and Ni were detected in some samples of wheat and barley of all origins, whereas other elements were at very low levels considered to be negligible concentrations.

scholarly journals Detection and Characterization of Human Enteroviruses, Human Cosaviruses, and a New Human Parechovirus Type in Healthy Individuals in Osun State, Nigeria, 2016/2017

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1037 ◽  
Author(s):  
Folakemi Abiodun Osundare ◽  
Oladele Oluyinka Opaleye ◽  
Akeem Abiodun Akindele ◽  
Samuel Adeyinka Adedokun ◽  
Olusola Anuoluwapo Akanbi ◽  
...  
Keyword(s):  
Healthy Individuals ◽  
Coding Region ◽  
Rt Pcr ◽  
Human Parechovirus ◽  
Full Genome Sequencing ◽  
Three Samples ◽  
Two Samples ◽  
Stool Samples ◽  
Pcr Assays ◽  
Species Specific

Human enteroviruses and human parechoviruses are associated with a broad range of diseases and even severe and fatal conditions. For human cosaviruses, the etiological role is yet unknown. Little is known about the circulation of non-polio enteroviruses, human parechoviruses, and human cosaviruses in Nigeria. A total of 113 stool samples were collected from healthy individuals in Osun State between February 2016 and May 2017. RT-PCR assays targeting the 5′ non-coding region (5′ -NCR) were used to screen for human enteroviruses, human parechoviruses, and human cosaviruses. For human enteroviruses, species-specific RT-PCR assays targeting the VP1 regions were used for molecular typing. Inoculation was carried out on RD-A, CaCo-2, HEp-2C, and L20B cell lines to compare molecular and virological assays. Ten samples tested positive for enterovirus RNA with 11 strains detected, including CV-A13 (n = 3), E-18 (n = 2), CV-A20 (n = 1), CV-A24 (n = 1), EV-C99 (n = 1), and EV-C116 (n = 2). Three samples tested positive for human parechovirus RNA, and full genome sequencing on two samples allowed assignment to a new Parechovirus A type (HPeV-19). Thirty-three samples tested positive for cosavirus with assignment to species Cosavirus D and Cosavirus A based on the 5′-NCR region. Screening of stool samples collected from healthy individuals in Nigeria in 2016 and 2017 revealed a high diversity of circulating human enteroviruses, human parechoviruses, and human cosaviruses. Molecular assays for genotyping showed substantial benefits compared with those of cell-culture assays.

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