scholarly journals Effect of Yttrium Oxide in Hydroxyapatite Biocomposite Materials: Electrical and Antimicrobial Evaluation

2021 ◽  
Author(s):  
G. M. Turky ◽  
Esmat Hamzawy ◽  
Gehan Bassyouny ◽  
Sayed Kenawy ◽  
Abeer A. Abd El-Aty
Keyword(s):  
Yttrium Oxide ◽  
Pathogenic Bacteria ◽  
Chemical Precipitation ◽  
Antimicrobial Activities ◽  
X Rays ◽  
Ionic Radii ◽  
Ft Ir ◽  
Mussel Shells ◽  
Bacteria And Fungi ◽  
Xrd Patterns

Abstract Synthesis and characterization of biocomposite materials of hydroxyapatite (HA) and yttrium oxide (Y2O3) were investigated. HA nanoparticles powder was obtained from mussel shells via a wet chemical precipitation routine. HA powder was doped with 1 and 2 wt% of Y2O3 . For microstructural examination, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) coupled with energy dispersive X-rays (EDX) were used. In addition, the dielectric and electrical properties and antimicrobial activities were investigated. XRD patterns reveal the crystallization of the oxyapatite. The peak intensities of pristine HA are inferior compared to the yttrium containing HA composites, thus suggesting that the addition of yttrium promotes the crystallization of HA due to the variance in their ionic radii. FT-IR shows a variation in the phosphate wavenumber, indicating the integration of yttrium into the HA matrix. SEM reveals nanorod- or worm-like crystals arose in clusters. With increasing Y2O3, from 1 to 2 wt%, the DC conductivity reduces from 16 to 9.3 nS/cm, which confirms that high amounts of Y3+ substitute Ca2+ in the HA matrix. In the high-frequency range, the AC conductivity linearly increases with increasing frequency following the universal power law. Further, antimicrobial activity results showed that the addition of yttrium in HA improves the antimicrobial effects against pathogenic bacteria and fungi. Additional research is needed to investigate the doping concentration of yttrium ions, and an anticipated property could be comprehended for several forthcoming biomedical applications

scholarly journals Antimicrobial Activities of Marine Sponge-Associated Bacteria

2021 ◽  
Vol 9 (1) ◽  
pp. 171
Author(s):  
Yitayal S. Anteneh ◽  
Qi Yang ◽  
Melissa H. Brown ◽  
Christopher M. M. Franco
Keyword(s):  
Pathogenic Bacteria ◽  
South Australia ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Marine Sponges ◽  
Bioactive Metabolites ◽  
Human Pathogens ◽  
Sponge Associated Bacteria ◽  
Microbial Symbionts ◽  
Bacteria And Fungi

The misuse and overuse of antibiotics have led to the emergence of multidrug-resistant microorganisms, which decreases the chance of treating those infected with existing antibiotics. This resistance calls for the search of new antimicrobials from prolific producers of novel natural products including marine sponges. Many of the novel active compounds reported from sponges have originated from their microbial symbionts. Therefore, this study aims to screen for bioactive metabolites from bacteria isolated from sponges. Twelve sponge samples were collected from South Australian marine environments and grown on seven isolation media under four incubation conditions; a total of 1234 bacterial isolates were obtained. Of these, 169 bacteria were tested in media optimized for production of antimicrobial metabolites and screened against eleven human pathogens. Seventy bacteria were found to be active against at least one test bacterial or fungal pathogen, while 37% of the tested bacteria showed activity against Staphylococcus aureus including methicillin-resistant strains and antifungal activity was produced by 21% the isolates. A potential novel active compound was purified possessing inhibitory activity against S. aureus. Using 16S rRNA, the strain was identified as Streptomyces sp. Our study highlights that the marine sponges of South Australia are a rich source of abundant and diverse bacteria producing metabolites with antimicrobial activities against human pathogenic bacteria and fungi.

scholarly journals Synthesis, Characterization, Semiempirical and Biological Activities of Organotin(IV) Carboxylates with 4-Piperidinecarboxylic Acid

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Shabbir Hussain ◽  
Saqib Ali ◽  
Saira Shahzadi ◽  
Saroj K. Sharma ◽  
Kushal Qanungo ◽  
...  
Keyword(s):  
Biological Activities ◽  
Free Ligand ◽  
Antimicrobial Activities ◽  
Heat Of Formation ◽  
Nucleophilic Attack ◽  
Carboxylate Ligand ◽  
Site Structure ◽  
Stability Of Complexes ◽  
Ft Ir ◽  
Bacteria And Fungi

Organotin (IV) carboxylates with the general formulae R2Sn(Cl)L [R = Me (1),n-Bu (2), Ph (3)] and R3SnL [R = Me (4), Ph (5)] have been synthesized by the reaction of 4-piperidinecarboxylic acid (HL) with KOH and R2SnCl2(R = Me,n-Bu, Ph)/R3SnCl (R = Me, Ph) in methanol under stirring conditions. The metal ligand binding site, structure, and stability of complexes have been verified by FT-IR, (1H,13C) NMR, EI-MS technique, and semiempirical study. The FT-IR data indicate the bidentate chelating mode of the carboxylate ligand which is also confirmed by semiempirical study. In solution state, five and four coordinated geometry around tin was confirmed by NMR spectroscopy. The EI-MS data agreed well with the molecular structure of the complexes. Thermodynamic parameters and molecular descriptors were calculated by using semiempirical PM3 method. HOMO-LUMO calculations show that chlorodiorganotin complexes are more susceptible to nucleophilic attack as compared to triorganotin complexes. Computed negative heat of formation indicates that complexes1–4are thermodynamically stable. The organotin(IV) carboxylates displayed powerful antimicrobial activities against various strains of bacteria and fungi and their minimal inhibitory concentration were also evaluated. The complexes exhibited comparatively higher hemolytic activity as compared to free ligand.

Synthesis, Characterisation, and Biological Properties of Oxidovanadium(IV) 3,5-Dinitrosalicylhydroxamate Complexes

2020 ◽  
Vol 73 (1) ◽  
pp. 61
Author(s):  
Bhanu Priya ◽  
Abhishek Kumar ◽  
Neeraj Sharma
Keyword(s):  
Magnetic Moment ◽  
Pathogenic Bacteria ◽  
Electrochemical Behaviour ◽  
Radical Scavenging ◽  
Biological Properties ◽  
Pyramidal Geometry ◽  
Elemental Analyses ◽  
Ft Ir ◽  
Bacteria And Fungi ◽  
Thermal Analysis Techniques

The new oxidovanadium(iv) complexes of composition [VO(3,5(NO2)2C6H2(OH)CONHO)2] 1 and [VO(acac)(3,5(NO2)2C6H2(OH)CONHO)] 2 (where acac=(CH3COCHCOCH3)–] have been synthesised by the reactions of VOSO4·5H2O and [VO(acac)2] with potassium 3,5-dinitrosalicylhydroxamate (3,5-(NO2)2SHK) and characterised by elemental analyses, molar conductivity, magnetic moment measurements and FT-IR, UV-vis, and electron spin resonance (ESR) spectroscopies and mass spectrometry. Infrared spectra of complexes have indicated bonding through oxygen atoms of carbonyl and hydroxamic groups (O,O coordination). The magnetic moment, ESR, and mass spectra of the complexes suggested their monomeric nature, and a distorted square-pyramidal geometry around the vanadium has tentatively been proposed. The electrochemical behaviour of 1 and 2 has been studied by cyclic voltammetry. Thermal behaviour of the complexes studied by thermogravimetric and differential thermal analysis techniques has yielded VO2 as the decomposition product. The invitro antimicrobial activity of the ligand and complexes has been assayed against pathogenic bacteria and fungi by the minimum inhibitory concentration (MIC) method. The invitro antioxidant activity of the complexes has been determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging method.

scholarly journals Effect of Different Formulations and Application Methods of Coral Calcium on its Remineralization Ability on Carious Enamel

2020 ◽  
Vol 8 (D) ◽  
pp. 94-99
Author(s):  
Ali Abdelnabi ◽  
Mermen Kamal Hamza ◽  
Ola M. El-Borady ◽  
Tamer M. Hamdy
Keyword(s):  
Calcium Level ◽  
Mineral Content ◽  
Argon Laser ◽  
Calcium Content ◽  
Chemical Precipitation ◽  
Control Group ◽  
X Rays ◽  
Ft Ir ◽  
Ir Analysis ◽  
Application Methods

BACKGROUND: Coral calcium is a new biomimetic product and dietary supplement which consists mainly of alkaline calcium carbonate. AIM: The aim of the current study is to compare the remineralization effect of coral calcium in different formulations and application methods. METHODS: A total of 35 extracted molars was collected, examined, and sectioned to obtain 70 sound enamel discs, all specimens were examined for calcium mineral content using energy dispersive analysis of X-rays (EDAX) coupled with scanning electron microscope. Hydroxyapatite (HA) nanoparticles were synthesized through wet chemical precipitation approach and characterized by transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) analysis. Teeth specimens were subjected to demineralization, and mineral content was measured, specimens were divided into ten groups according to the remineralizing agent used, where Groups 1–3 used 10, 20, and 30 weight % (wt.%) coral calcium gel, respectively, Groups 4–6 used 10, 20, and 30 wt.% coral calcium and nanohydroxyapatite mix gel, and Groups 7–9 used 10, 20, and 30 wt.% coral calcium with argon laser activation and Group 10 (control group) without a remineralizing agent. All groups were re-examined by EDAX after remineralization. RESULTS: The TEM and FT-IR analysis confirmed the formation of rod shape HA in nanoparticles size range. All groups showed a statistically significant decrease in calcium level after demineralization, all groups showed a statistically significant increase in calcium content after remineralization except for the control group. Moreover, Groups 2 and 8 showed the highest increase in calcium level after remineralization. CONCLUSION: Coral calcium showed a significant remineralizing effect on carious enamel (demineralization) with an optimum concentration of 20 wt.%.

scholarly journals Isolation and Identification of Saccharomyces cerevisiae from Caterpillar Frass and their Probiotic Characterization

2019 ◽  
Vol 16 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Ujwala Vinayak Khisti ◽  
Suyash Arun Kathade ◽  
Mayur Arjun Aswani ◽  
Pashmin Kaur Anand ◽  
Nirichan Kunchirman Bipinraj
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Pathogenic Bacteria ◽  
Antimicrobial Activities ◽  
Yeast Cells ◽  
Isolation And Identification ◽  
Yeast Cultures ◽  
Isolation And Characterization ◽  
Wide Range ◽  
Probiotic Yeast ◽  
Bacteria And Fungi

Probiotics are live microorganisms which upon ingestion confer health benefits to the host and are widely applied for human and animal welfare. The present study reports the isolation of yeast cells from caterpillar frasses and its probiotic characterization. Out of four yeast cultures isolated, all found to be non-hemolytic and cultures designated as CV-I, CV-II CV-III and CV-IV showed good bile tolerance at 1.2%. These cultures possessed the ability to grow pH range of 1.5 – 10, exhibited auto-aggregation and co-aggregation capabilities, which are essential for growth in alimentary canal and reduction of pathogen adherence on the intestinal epithelial cells. All cultures exhibited good tolerance to temperature up to 42°C. Isolate CV-I showed wide range of antimicrobial activities against pathogenic bacteria and fungi. This study is the first report of isolation and characterization of probiotic yeast from caterpillar frass. The isolate CV-I has been identified as Saccharomyces cerevisiae by molecular methods. This culture is an ideal candidate for further probiotic exploration.

In-Vitro Cytotoxicity, Antimicrobial activities and DNA binding studies, of Novel Copper (II) complex with Heterocyclic base

2021 ◽  
pp. 3051-3055
Author(s):  
Shalini V. ◽  
Deepika R. ◽  
Arumugham M. N
Keyword(s):  
Dna Binding ◽  
Pathogenic Bacteria ◽  
Spectroscopic Method ◽  
Antimicrobial Activities ◽  
In Vitro Cytotoxicity ◽  
Binding Studies ◽  
Heterocyclic Base ◽  
Heterocyclic Ligand ◽  
Bacteria And Fungi

A novel ternary copper (II) complex have been synthesized by the addition of N, N-heterocyclic ligand with L-amino acid. The copper (II) complex, [Cu(1,10-phen) (L-Thr) Br] (where phen=1,10-phenanthroline and Threo=Threonine) characterized by various spectroscopic method. The intense UV band around 271nm was due to π-π* transition. The DNA binding study of these copper (II) complex are examined by UV–Visible, Emission spectroscopic, cyclic voltammetric and viscosity method. The results revealed that complex shown to be a intercalation mode of binding into DNA. The anticancer activity of Cu (II) complexes has capability to the kill HepG2 liver cancer cell as assessed by the MTT method, The Ic50value was found 21.50µg/ml The biological activity of the complex tested against certain pathogenic bacteria and fungi results revealed it was found to be potent antibacterial agent.

scholarly journals Antimicrobial activities of chicken β-defensin (4 and 10) peptides against pathogenic bacteria and fungi

2015 ◽  
Vol 5 ◽  
Author(s):  
Haitham A. Yacoub ◽  
Ahmed M. Elazzazy ◽  
Osama A. H. Abuzinadah ◽  
Ahmed M. Al-Hejin ◽  
Maged M. Mahmoud ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Antimicrobial Activities ◽  
Bacteria And Fungi
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