scholarly journals Phyto-Nanocatalysts: Green Synthesis, Characterization, and Applications

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3418 ◽  
Author(s):  
Fierascu ◽  
Ortan ◽  
Avramescu ◽  
Fierascu
Keyword(s):  
Chemical Composition ◽  
Plant Extracts ◽  
Metallic Nanoparticles ◽  
Chemical Processes ◽  
Metallic Oxides ◽  
New Methods ◽  
Methods Of Synthesis ◽  
Promising Area ◽  
Shape Of Nanoparticles ◽  
Almost All

Catalysis represents the cornerstone of chemistry, since catalytic processes are ubiquitous in almost all chemical processes developed for obtaining consumer goods. Nanocatalysis represents nowadays an innovative approach to obtain better properties for the catalysts: stable activity, good selectivity, easy to recover, and the possibility to be reused. Over the last few years, for the obtaining of new catalysts, classical methods—based on potential hazardous reagents—have been replaced with new methods emerged by replacing those reagents with plant extracts obtained in different conditions. Due to being diversified in morphology and chemical composition, these materials have different properties and applications, representing a promising area of research. In this context, the present review focuses on the metallic nanocatalysts’ importance, different methods of synthesis with emphasis to the natural compounds used as support, characterization techniques, parameters involved in tailoring the composition, size and shape of nanoparticles and applications in catalysis. This review presents some examples of green nanocatalysts, grouped considering their nature (mono- and bi-metallic nanoparticles, metallic oxides, sulfides, chlorides, and other complex catalysts).

ASSESSMENT OF TOXICITY OF GERMANIUM COORDINATION COMPOUNDS

2019 ◽  
pp. 16-21
Author(s):  
A. V. Kadomtsevа ◽  
I. V. Zhdanovich ◽  
M. S. Piskunovа ◽  
A. N. Lineva ◽  
A. N. Novikova ◽  
...  
Keyword(s):  
Coordination Compounds ◽  
Organometallic Compounds ◽  
Biologically Active ◽  
Pharmacological Properties ◽  
Toxicological Studies ◽  
Methods Of Synthesis ◽  
Promising Area

The synthesis of biologically active coordination compounds and the design on their basis of effective pharmacological preparations is currently the promising area. This paper presents the results of the toxicological studies on digermanium and its complex derivatives. It should be noted that the positive medical properties of organometallic compounds of germanium are confirmed by numerous studies, therefore, the development of the methods of synthesis, as well as investigations of physicochemical and pharmacological properties of these compounds are at the center of attention.

Chemical Composition and Antimicrobial Activity of Bark and Leaf Extracts of Cupressus sempervirens and Juniperus phoenicea Grown in Al- Jabel Al-Akhdar Region, Libya

2019 ◽  
Vol 9 (4) ◽  
pp. 268-279
Author(s):  
Mohamed E.I. Badawy ◽  
Ibrahim E.A. Kherallah ◽  
Ahmed S.O. Mohareb ◽  
Mohamed. Z.M. Salem ◽  
Hameda A. Yousef
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Sea Level ◽  
Plant Extracts ◽  
Complex Mixture ◽  
Biologically Active ◽  
Cupressus Sempervirens ◽  
Leaf Extracts ◽  
Juniperus Phoenicea ◽  
The Impact

Background:Plant extracts are important products in the world and have been widely used for isolation of important biologically active products. Because of their significant environmental impact, extensive research has been explored to determine the antimicrobial activity of plant extracts.Methods:Acetone extracts of the bark and leaf of Cupressus sempervirens and Juniperus phoenicea, collected from three different altitudes (125, 391, and 851 m high of sea level) at Al- Jabel Al-Akhdar area, Libya were obtained and analyzed by GC/MS. The antimicrobial activity of the extracts was further evaluated against plant bacteria Rhizobium radiobacter, Erwinia carotovora, Rhodococcus fascians and Ralstonia solanacearum and fungus Botrytis cinerea.Results:The impact of the altitude from the sea level on the quantity and chemical constituents of the extracts was investigated. The yield was largely dependent on tree species and the highest yield (6.50%) was obtained with C. sempervirens L bark of altitude III (851 m of the sea level), while the lowest (1.17%) was obtained with the leaf extract of C. sempervirens L from altitude I (125 m). The chemical composition analyzed by GC/MS confirmed that the leaf extracts of C. sempervirens and J. phoenicea contained a complex mixture of monoterpene hydrocarbons, sesquiterpenes, diterpenes, diterpenoids, terpenophenolic, steroids and phthalates. However, the bark extracts of both trees contained a mixture of sesquiterpenes, diterpenes, diterpenoids, terpenophenolics, phthalates, retinol and steroids. These constituents revealed some variability among the extracts displaying the highest interesting chemotype of totarol (terpenophenolic) in all extracts (14.63-78.19% of the total extract). The extracts displayed a noteworthy antifungal potency with varying degrees of inhibition of growth with EC50 values ranged from 78.50 to 206.90 mg/L. The extracts obtained from the leaves of C. sempervirens showed that the highest inhibitory activity was obtained with the extract of altitude II (391 m) with MIC 565, 510, 380 and 710 mg/L against E. carotovora, R. fascians, and R. radiobacter and R. solanacearum, respectively.Conclusion:Based on antimicrobial activity, raw plant extracts can be a cost-effective way to protect crops from microbial pathogens. Because plant extracts contain several antimicrobial compounds, the development of resistant pathogens can be delayed.

Green synthesis of silver nanoparticles using sustainable resources and their use as antibacterial agents: A review

2020 ◽  
Vol 13 ◽  
Author(s):  
Kumari Jyoti ◽  
Punyasloka Pattnaik ◽  
Tej Singh
Keyword(s):  
Silver Nanoparticles ◽  
Plant Extracts ◽  
Metallic Nanoparticles ◽  
Cost Effective ◽  
Biological Properties ◽  
Metal Species ◽  
Sustainable Resources ◽  
Research Areas ◽  
Low Toxicity

Background:: Synthesis of metallic nanoparticles has attracted extensive vitality in numerous research areas such as drug delivery, biomedicine, catalysis etc. where continuous efforts are being made by scientists and engineers to investigate new dimensions for both technological and industrial advancements. Amongst numerous metallic nanoparticles, silver nanoparticle (AgNPs) is a novel metal species with low toxicity, higher stability and significant chemical, physical and biological properties. Methods:: In this, various methods for the fabrication of AgNPs are summarized. Importantly, we concentrated on the role of reducing agents of different plants parts, various working conditions such as AgNO3 concentration; ratio of AgNO3/extract; incubation time; centrifugal conditions, size and shapes. Results:: This study suggested that eco-friendly and non toxic biomolecules present in the extracts (e.g. leaf, stem and root) of plants are used as reducing and capping agents for silver nanoparticles fabrication. This method of fabrication of silver nanoparticles using plants extracts is comparatively cost-effective and simple. A silver salt is simply reduced by biomolecules present in the extracts of these plants. In this review, we have emphasized the synthesis and antibacterial potential of silver nanoparticles using various plant extracts. Conclusion:: Fabrication of silver nanoparticles using plant extracts have advantage over the other physical methods, as it is safe, eco-friendly and simple to use. Plants have huge potential for the fabrication of silver nanoparticles of wide potential of applications with desired shape and size.

scholarly journals Research Regarding the Quality of Lambs Carcass Resulted from Tsigaia Purebred Compared with Hybrids of Tsigaia Ewes Crossed with Blanc du Massif Central Rams

2017 ◽  
Vol 74 (1) ◽  
pp. 7
Author(s):  
Mihai Marian BORZAN ◽  
Dana PUSTA ◽  
Liviu BOGDAN ◽  
Alexandra TABARAN ◽  
Attila MATE ◽  
...  
Keyword(s):  
Body Weight ◽  
Chemical Composition ◽  
Massif Central ◽  
Live Body Weight ◽  
Almost All ◽  
Qualitative Characteristics

Abstract: The research aims to compare some qualitative characteristics of purebred Tsigaia lambs and Tsigaia crossed with Blanc du Massif Central lambs. The criteria assessed were: chemical composition of purebred and Tsigaia crossed meat, the live body weight, the slaughtering performance, the weight of different carcass cut. For almost all criteria chosen the crossed individuals registered better results.

scholarly journals The Benefits of Smart Nanoparticles in Dental Applications

2021 ◽  
Vol 22 (5) ◽  
pp. 2585
Author(s):  
Silvia Vasiliu ◽  
Stefania Racovita ◽  
Ionela Aurica Gugoasa ◽  
Maria-Andreea Lungan ◽  
Marcel Popa ◽  
...  
Keyword(s):  
Metallic Nanoparticles ◽  
Periodontal Diseases ◽  
Dental Materials ◽  
Moisture Stress ◽  
New Methods ◽  
Strong Trend ◽  
Scientific World ◽  
Oral Environment ◽  
Recent Developments ◽  
Dental Applications

Dentistry, as a branch of medicine, has undergone continuous evolution over time. The scientific world has focused its attention on the development of new methods and materials with improved properties that meet the needs of patients. For this purpose, the replacement of so-called “passive” dental materials that do not interact with the oral environment with “smart/intelligent” materials that have the capability to change their shape, color, or size in response to an externally stimulus, such as the temperature, pH, light, moisture, stress, electric or magnetic fields, and chemical compounds, has received much attention in recent years. A strong trend in dental applications is to apply nanotechnology and smart nanomaterials such as nanoclays, nanofibers, nanocomposites, nanobubbles, nanocapsules, solid-lipid nanoparticles, nanospheres, metallic nanoparticles, nanotubes, and nanocrystals. Among the nanomaterials, the smart nanoparticles present several advantages compared to other materials, creating the possibility to use them in various dental applications, including preventive dentistry, endodontics, restoration, and periodontal diseases. This review is focused on the recent developments and dental applications (drug delivery systems and restoration materials) of smart nanoparticles.

Epicuticular waxes of the genus Hordeum: a survey of their chemical composition and ultrastructure

1989 ◽  
Vol 67 (11) ◽  
pp. 3219-3226 ◽  
Author(s):  
Bernard R. Baum ◽  
A. Pat Tulloch ◽  
L. Grant Bailey
Keyword(s):  
Chemical Composition ◽  
Discriminant Analysis ◽  
Alcohol Content ◽  
Total Absence ◽  
Average Alcohol ◽  
The Common ◽  
Group 2 ◽  
Whole Plants ◽  
Almost All ◽  
Group 1

This study was based on 148 accessions representing 39 species of Hordeum. SEM ultrastructural morphology of waxes was based on individual spikelets, whereas waxes' chemical composition was assessed from whole plants. When all the data, in the form of individual accessions, were subjected to various cluster analyses methods, no groupings were revealed. But when the data were first summarized by species and then subjected to clustering, two polythetic groups of species were detected. Group 1 is characterized by species with 40–60% average alcohol content and by the common presence of diketones, whereas group 2 is characterized by species with 61 – 80% average alcohol content, by the total absence of hydroxy-β-diketone, and almost all species without β-diketone. The chemical data were then subjected to classificatory discriminant analysis to assess if a single previously unclassified accession could be identified into one of the two groupings. The nature of the differences between the two groupings was described by means of a canonical discriminant analysis. Mostly only plates and filaments were detected, and in many accessions the filaments were widened, appeared platelike, and were characteristic for one group. Presence of β-diketone varied within species. Hordeum violaceum was found to be unique in chemical composition.

scholarly journals Influences of Bath Chemistry and Plating Variables on Characteristics of Electroless Ni–P Films on Si Wafers from Alkaline Citrate Solutions

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Naiming Miao ◽  
Jinjin Jiang ◽  
Wangping Wu
Keyword(s):  
Thermal Stability ◽  
Chemical Composition ◽  
Deposition Rate ◽  
Electroless Nickel ◽  
Monocrystalline Silicon ◽  
P Content ◽  
Almost All ◽  
P Type ◽  
Electroless Ni ◽  
Thermal Stability Of

Electroless nickel–phosphorus (Ni–P) films were produced on the surface of p-type monocrystalline silicon in the alkaline citrate solutions. The influences of bath chemistry and plating variables on the chemical composition, deposition rate, morphology, and thermal stability of electroless Ni–P films on silicon wafers were studied. The as-deposited Ni–P films were almost all medium- and high-P deposits. The concentrations of Ni2+ and citric ions influenced the deposition rate of the films but did not affect P content in the deposits. With increasing H2PO2− content, the P content and deposition rate were steadily increased. The pH and plating temperature had a significant effect on the chemical composition and the deposition rate of the films. The thermal stability of the medium-P film was better than that of the high-P deposit. At the same time, the proposed mechanism of Ni–P films on monocrystalline silicon substrates in the alkaline bath solution was discussed and addressed.

scholarly journals AROMI NATURALI: LEGISLAZIONE E SINTESI

2020 ◽  
Author(s):  
Stefano Serra
Keyword(s):  
Legal Regulations ◽  
New Methods ◽  
Methods Of Synthesis ◽  
Natural Flavors

This report describes the legal regulations concerning flavour production, classification and marketing. The effect that the legislation itself has brought in the development of new methods of synthesis of natural flavors is described in detail.

Sign in / Sign up

Export Citation Format

Share Document