scholarly journals Antifungal potential, chemical composition of Chlorella vulgaris and SEM analysis of morphological changes in Fusarium oxysporum

2021 ◽  
Author(s):  
Kahkashan Perveen ◽  
Najat A. Bukhari ◽  
Luluah M. Al Masoudi ◽  
Amera Naser Alqahtani ◽  
Mashael W Alruways ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Fusarium Oxysporum ◽  
Chlorella Vulgaris ◽  
Morphological Changes ◽  
Sem Analysis ◽  
Antifungal Potential

Effects of Aging on the Morphology of Rubber-Brass Interfacial Layer

2011 ◽  
Vol 39 (1) ◽  
pp. 20-43 ◽  
Author(s):  
A. Ashirgade ◽  
P. B. Harakuni ◽  
W. J. Vanooij
Keyword(s):  
Chemical Composition ◽  
Interfacial Layer ◽  
Secondary Ion Mass Spectrometry ◽  
Morphological Changes ◽  
Grazing Incidence ◽  
Complex Nature ◽  
Rubber Compound ◽  
Tire Cord ◽  
Morphological Transformation ◽  
Adhesion Promoter

Abstract Adhesion between rubber compound and brass-plated steel tire cord is crucial in governing the overall performance of tires. The rubber-brass interfacial adhesion is influenced by the chemical composition and thickness of the interfacial layer. It has been shown that the interfacial layer consists mainly of sulfides and oxides of copper and zinc. This paper discusses the effect of changes in the chemical composition and the structure of the interfacial layers due to addition of adhesion promoter resins. Grazing incidence x-ray diffraction (GIXRD) experiments were run on sulfidized polished brass coupons previously bonded to five experimental rubber compounds. It was confirmed that heat and humidity conditions lead to physical and chemical changes of the rubber-steel tire cord interfacial layer, closely related to the degree of rubber-brass adhesion. Morphological transformation of the interfacial layer led to loss of adhesion after aging. The adhesion promoter resins inhibit unfavorable morphological changes in the interfacial layer, thus stabilizing it during aging and prolonging failure. Tire cord adhesion tests illustrated that the one-component resins improved adhesion after aging using a rubber compound with lower cobalt loading. Based on the acquired diffraction profiles, these resins were also found to impede crystallization of the sulfide layer after aging, leading to improved adhesion. Secondary ion mass spectrometry depth profiles and scanning electron microscopy micrographs strongly corroborated the findings from GIXRD. This interfacial analysis adds valuable information to our understanding of the complex nature of the rubber-brass bonding mechanism.

scholarly journals Evaluation of ionic degradation and slot corrosion of metallic brackets by the action of different dentifrices

2013 ◽  
Vol 18 (1) ◽  
pp. 86-93
Author(s):  
Gustavo Antônio Martins Brandão ◽  
Rafael Menezes Simas ◽  
Leandro Moreira de Almeida ◽  
Juliana Melo da Silva ◽  
Marcelo de Castro Meneghim ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Artificial Saliva ◽  
Positive Control ◽  
Negative Control ◽  
Sem Analysis ◽  
Wilcoxon Test ◽  
Surface Polishing ◽  
Aluminium Ion ◽  
Negative Controls

OBJECTIVE: To evaluate the in vitro ionic degradation and slot base corrosion of metallic brackets subjected to brushing with dentifrices, through analysis of chemical composition by Energy Dispersive Spectroscopy (EDS) and qualitative analysis by Scanning Electron Microscopy (SEM). METHODS: Thirty eight brackets were selected and randomly divided into four experimental groups (n = 7). Two groups (n = 5) worked as positive and negative controls. Simulated orthodontic braces were assembled using 0.019 x 0.025-in stainless steel wires and elastomeric rings. The groups were divided according to surface treatment: G1 (Máxima Proteção Anticáries®); G2 (Total 12®); G3 (Sensitive®); G4 (Branqueador®); Positive control (artificial saliva) and Negative control (no treatment). Twenty eight brushing cycles were performed and evaluations were made before (T0) and after (T1) experiment. RESULTS: The Wilcoxon test showed no difference in ionic concentrations of titanium (Ti), chromium (Cr), iron (Fe) and nickel (Ni) between groups. G2 presented significant reduction (p < 0.05) in the concentration of aluminium ion (Al). Groups G3 and G4 presented significant increase (p < 0.05) in the concentration of aluminium ion. The SEM analysis showed increased characteristics indicative of corrosion on groups G2, G3 and G4. CONCLUSION: The EDS analysis revealed that control groups and G1 did not suffer alterations on the chemical composition. G2 presented degradation in the amount of Al ion. G3 and G4 suffered increase in the concentration of Al. The immersion in artificial saliva and the dentifrice Máxima Proteção Anticáries® did not alter the surface polishing. The dentifrices Total 12®, Sensitive® and Branqueador® altered the surface polishing.

scholarly journals Ultra-Morphological Changes of Trichophyton Rubrum Treated with Hydroxychavicol

2020 ◽  
Vol 16 (2) ◽  
Author(s):  
P. M. Ridzuan ◽  
Nasir Mohamad ◽  
Salwani Ismail ◽  
Nor Iza A. Rahman ◽  
Sanusi N.A ◽  
...  
Keyword(s):  
Trichophyton Rubrum ◽  
Morphological Changes ◽  
Treated Group ◽  
Fungal Species ◽  
Skin Infections ◽  
Betel Leaf ◽  
Transmission Electron ◽  
Antifungal Potential ◽  
Resistant Strains ◽  
Preliminary Study

Trichophyton rubrum is a common pathogenic fungal species that is responsible for causing infection on human skin, hair and nail. The antifungal-resistant strains complicate the treatment regime. Hydroxychavicol (HC) is one of the main compounds from Piper betel leaf that have antifungal potential and its mechanism of action has not been studied yet. The objective of this preliminary study to determine the antifungal properties of HC against T. rubrum using transmission electron microscope (TEM) on gross and ultrastructure of T. rubrum hypha. T. rubrum was treated with HC and miconazole (MI) at concentrations of 1.25, 2.5, 5 and 10 mg/mL for 1, 3, 5 and 7 days continuously. Generally, fungi structures became more severely damaged at increasing treatment duration. Microscopically, the fungi’s cell wall treated with HC showed a rough surface, shrinkage and demolition similar to the MI treated group. The fungi organelles were also demolished and disorganized. This study revealed that HC has the ability to inhibit T. rubrum growth and has potential to be an antifungal agent for skin infections.

scholarly journals Phytochemical screening and antifungal potentials of Citrus limon peels against Fusarium oxysporum and Rhizopus stolonifer causing rots in water melon (Citrullus lanatus L.)

2020 ◽  
pp. 17-21
Author(s):  
L.U. Bashir ◽  
A. Abdulkadir ◽  
M. M. Shah ◽  
A. Hamisu ◽  
U. Sharif ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Citrullus Lanatus ◽  
Citrus Limon ◽  
Pathogenicity Test ◽  
Phytochemical Screening ◽  
Rhizopus Stolonifer ◽  
Methanol Extracts ◽  
Antifungal Potential ◽  
Phytochemical Constituents ◽  
Water Melon

This study investigated the phytochemical constituents and antifungal potential of Citrus limon peels using aqueous and methanol extracts against Fusarium oxysporum and Rhizopus stolonifer causing rots in water melon. The result of phytocemical screening revealed the presence of Saponin, Tannin, Phenols, Alkaloid and Flavanoid. Pathogenicity test conducted showed that F. oxysporum and R. stolonifer causes rots of Citrullus lanatus. The extracts inhibited the growth of F. oxysporum (76.67% and 60.00 %) methanol and aqueous respectively. R. stolonifer growth was inhibited (85.93% and 71.11%) methanol and aqueous extracts. The fungitoxicity of synthetic fungicide Benomyl was 95.56%. The methanol extracts has highest inhibitory activity than aqueous extract. The result of the findings indicates the Biofungicide potentials of Citrus limon peels as alternative to synthetic fungicide in management of phyto-pathogens of water lemon.

scholarly journals Facile Synthesis of SnS Nanostructures With Different Morphologies for Supercapcitor and Dye-Sensitized Solar Cell Applications

2021 ◽  
Author(s):  
Mohd Arif Dar ◽  
D. Govindarajaran ◽  
Gulam Nabi Dar
Keyword(s):  
Morphological Changes ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Orthorhombic Phase ◽  
Sem Analysis ◽  
Tin Sulfide ◽  
Counter Electrodes ◽  
X Ray ◽  
Dye Sensitized ◽  
Direct Energy

Abstract In this paper, Tin Sulfide (SnS) nanoparticles is synthesized with three different solvents through hydrothermal method and characterized by using X-Ray diffraction, scanning electron microscopy, UV–Drs spectroscopy, Fourier transform infrared spectroscopy, Energy Dispersive X- ray spectrum, Supercapcitor and photovoltaic performance. XRD patterns indicate that the prepared SnS nanoparticles exist in the orthorhombic phase. The SEM analysis clearly picturize the morphological changes in the SnS nanoparticles synthesized through different solvents. The UV-Drs spectrum gives direct energy band gap which lies between 1.0 eV to 2.0 eV. The FT-IR spectrum explains various functional groups present in the SnS nanoparticles. The prepared SnS counter electrodes (CEs) showed good electrocatalytic activity in the redox reaction of the I−/I3−. The efficiency of SnS-e, SnS-a and SnS-m counter electrodes are 9.99 %, 9.90 % and 9.86 % in Dye-sensitized solar cells (DSSC) than that of platinum counter electrode which is 9.80 %. The specific capacitance of 284 F/g is obtained for SnS-e electrode at a current density of 5 A/g and an energy density of 216 Wh/kg corresponding to power density value of 1.6 KWh/kg which proves SnS-e electrode possesses better capacitive performance.

Chemical composition and antifungal potential of Iranian propolis against Candida krusei strains

2017 ◽  
Vol 56 (5) ◽  
pp. 581-587 ◽  
Author(s):  
Hojjatollah Shokri ◽  
Farzad Katiraee ◽  
Mahnaz Fatahinia ◽  
Mohammad Hassan Minooeianhaghighi
Keyword(s):  
Chemical Composition ◽  
Candida Krusei ◽  
Antifungal Potential

scholarly journals Chemical Composition and Preliminary Antimicrobial Activity of the Hydroxylated Sesquiterpenes in the Essential Oil from Piper barbatum Kunth Leaves

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 211 ◽  
Author(s):  
Paco Noriega ◽  
José Ballesteros ◽  
Alejandra De la Cruz ◽  
Tatiana Veloz
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Chemical Composition ◽  
Essential Oil ◽  
Forest Ecosystem ◽  
Raw Materials ◽  
The Andes ◽  
Ancestral Knowledge ◽  
Antifungal Potential

This study evaluates the antimicrobial and antifungal potential of the essential oil extracted from a species located in the Andes of Ecuador, Piper barbatum Kunth, known as “cordoncillo” or “allupa”, used by the Quichua people as an antibacterial plant for washing female genitalia in cases of infection. The most abundant molecules in the essential oil were: α- phellandrene (43.16%), limonene (7.04%); some oxygenated sesquiterpenes such as: trans-sesquisabinene hydrate (8.23%), elemol (7.21%) and others. The evaluation of antimicrobial activity showed activity in all the strains analyzed; however, those in which MIC values are considered to be very strong (less than 500 µg/mL) are: Staphylococcus aureus 264 µg/mL, Streptococcus mutans 132 µg/mL, Candida albicans 132 µg/mL and Candida tropicalis 264 µg/mL. Antimicrobial bioautography defines which molecules are responsible for the activity; thus, it was possible to establish the chromatographic regions of = 0.02 and Rf = 0.04, as those with active molecules. It was established that 4 hydroxylated sesquiterpene molecules are involved: elemol (7.21%), trans-sesquisabinene hydrate (8.23%), β–eudesmol (3.49%) and 10-epi-γ-eudesmol (1.07%); the last two being the most active. The aim of this manuscript is to analyze both the ancestral knowledge of the Quichua people of Ecuador, and the chemical-biodiversity of the Andean forest ecosystem, in order to provide new raw materials of pharmaceutical interest.

scholarly journals Cation Doping Approach for Nanotubular Hydrosilicates Curvature Control and Related Applications

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 654
Author(s):  
Andrei A. Krasilin ◽  
Ekaterina K. Khrapova ◽  
Tatiana P. Maslennikova
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
Morphological Changes ◽  
High Technology ◽  
Synthetic Approach ◽  
Cation Doping ◽  
The Past ◽  
Technology Applications ◽  
Curvature Control ◽  
Uptake And Release

The past two decades have been marked by an increased interest in the synthesis and the properties of geoinspired hydrosilicate nanoscrolls and nanotubes. The present review considers three main representatives of this group: halloysite, imogolite and chrysotile. These hydrosilicates have the ability of spontaneous curling (scrolling) due to a number of crystal structure features, including the size and chemical composition differences between the sheets, (or the void in the gibbsite sheet and SiO2 tetrahedron, in the case of imogolite). Mineral nanoscrolls and nanotubes consist of the most abundant elements, like magnesium, aluminium and silicon, accompanied by uncontrollable amounts of impurities (other elements and phases), which hinder their high technology applications. The development of a synthetic approach makes it possible to not only to overcome the purity issues, but also to enhance the chemical composition of the nanotubular particles by controllable cation doping. The first part of the review covers some principles of the cation doping approach and proposes joint criteria for the semiquantitative prediction of morphological changes that occur. The second part focuses on some doping-related properties and applications, such as morphological control, uptake and release, magnetic and mechanical properties, and catalysis.

scholarly journals EVALUATION OF ANTIFUNGAL POTENTIAL OF ALLIUM AMPELOPRASUM AGAINST FUNGAL PHYTOPATHOGENS

2018 ◽  
Vol 11 (11) ◽  
pp. 129
Author(s):  
Shahid Khan ◽  
Amandeep Kaur ◽  
Neeta Raj Sharma
Keyword(s):  
Chemical Composition ◽  
Antifungal Activity ◽  
Inhibitory Concentration ◽  
Economic Importance ◽  
Allium Ampeloprasum ◽  
Water Extracts ◽  
Maximum Inhibition ◽  
Antifungal Potential ◽  
Organic Extracts ◽  
Fungal Phytopathogens

Objective: Present study evaluates the antifungal potential of Allium ampeloprasum extracts against two phytopathogens of economic importance, namely Alternaria triticina and Magnaporthe oryzae which are found to be one of the greatest threats to wheat and rice crop worldwide.Methods: Four different organic solvents, i.e., water, methanol, acetone, and hexane were used for extract preparation based on the increasing order of polarity. Further, different concentrations of these extracts were used to perform a quantitative assay for measuring the antifungal activity of extracts. Two-way analysis of variance was used to statistically analyze the results through GraphPad Prism v. 7.00.Results: The best results were shown by water extracts with a maximum inhibition of 99.39±0.2% against A. triticina and 99.39±2.2% against M. oryzae. Water extracts gave minimal inhibitory concentration 90 values at 9.94 μg/mL against M. oryzae and at 16.73 μg/mL against A. triticina.Conclusion: Water extracts of A. ampeloprasum have relatively higher potential for being used as an antifungal agent as compared to other organic extracts used in this study. Further study on the chemical composition of A. ampeloprasum water extracts can reveal potent anti-phytopathogenic fungal compounds which can be used to develop biofungicides.

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