scholarly journals Sintered and 3D-Printed Bulks of MgB2-Based Materials with Antimicrobial Properties

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 6045
Author(s):  
Petre Badica ◽  
Nicolae Dan Batalu ◽  
Mariana Carmen Chifiriuc ◽  
Mihail Burdusel ◽  
Mihai Alexandru Grigoroscuta ◽  
...  
Keyword(s):  
Antimicrobial Properties ◽  
Bacterial Strains ◽  
E Coli ◽  
Plasma Sintering ◽  
Complex Shapes ◽  
Spark Plasma ◽  
Powder Particles ◽  
3D Printed ◽  
Printed Materials

Pristine high-density bulk disks of MgB2 with added hexagonal BN (10 wt.%) were prepared using spark plasma sintering. The BN-added samples are machinable by chipping them into desired geometries. Complex shapes of different sizes can also be obtained by the 3D printing of polylactic acid filaments embedded with MgB2 powder particles (10 wt.%). Our present work aims to assess antimicrobial activity quantified as viable cells (CFU/mL) vs. time of sintered and 3D-printed materials. In vitro antimicrobial tests were performed against the bacterial strains Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Enterococcus faecium DSM 13590, and Enterococcus faecalis ATCC 29212; and the yeast strain Candida parapsilosis ATCC 22019. The antimicrobial effects were found to depend on the tested samples and microbes, with E. faecium being the most resistant and E. coli the most susceptible.

scholarly journals Epilobi Hirsuti Herba Extracts Influence the In Vitro Activity of Common Antibiotics on Standard Bacteria

2016 ◽  
Vol 14 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Lucia Pirvu ◽  
Isabela Nicorescu ◽  
Cristina Hlevca ◽  
Bujor Albu ◽  
Valentin Nicorescu
Keyword(s):  
Synergistic Effects ◽  
Herbal Medicines ◽  
Antimicrobial Properties ◽  
Inhibition Zone ◽  
In Vitro Activity ◽  
Bacterial Strains ◽  
Gram Negative ◽  
E Coli ◽  
Effective Source

AbstractEpilobium genus has been confirmed as an effective source of natural antimicrobials. However, the influence of Epilobi hirsuti herba derived products on usual antibiotics activity has not been studied. In this study, several standardized Epilobi hirsuti herba extracts (EHE) were evaluated in order to asses their potential effects on usual antibiotics tested on standard Gram-positive and Gram-negative bacterial strains in vitro. The results emphasized that the bacterial strains ranged from sensitive (MIC values between 50–200 μg GAE mL-1) (S. epidermidis ATCC 12228) to very resistant (E. coli strains), E. faecalis ATCC 29212 being practically immune to EHE. In terms of synergistic interaction, Tetracycline and Ampicillin combinations lead to the most important stimulatory effects, the diameters of the inhibition zone being even 60% bigger compared to the antibiotic alone. Synergistic effects between myricetin(galloyl) derivates and Tetracycline were also revealed on P. aeruginosa and E. coli strains. Together, it clearly demonstrated not only EHE’s own antimicrobial properties, but also their capacity to influence the antimicrobial potency of some common antibiotics. These results could be useful for the area of herbal medicines and as potential candidates in managing microbial resistance, but also for physicians and pharmacists using combined antibacterial therapy.

scholarly journals Antibacterial Activity of Aqueous Extracts of Anacyclus Pyrethrum (L) Link and Corrigiola Telephiifolia Pourr. From the Middle Atlas Region-Morocco

2017 ◽  
Vol 13 (33) ◽  
pp. 116 ◽  
Author(s):  
Daoudi Amine ◽  
Bammou Mohamed ◽  
Ibijbijen Jamal ◽  
Nassiri Laila
Keyword(s):  
Gallic Acid ◽  
Aqueous Extract ◽  
Antimicrobial Properties ◽  
Inhibition Zone ◽  
Aqueous Extracts ◽  
Bacterial Strains ◽  
E Coli ◽  
Disk Diffusion Assay ◽  
Middle Atlas

Aqueous extracts of Corrigiola telephiifolia and Anacyclus pyrethrum were studied in vitro for their antimicrobial properties. These plants were collected from the Central Middle Atlas region. Corrigiola telephiifolia Pourr. and Anacyclus pyrethrum (L.) Link are widely used as a natural drug for the treatment of various infectious diseases. Phytochemical screening of the plants showed the presence of flavonoids, saponins, tannins, steroids and alkaloids. The determination of the polyphenols in the aqueous extract of the two plants revealed the presence of significant amounts of polyphenols (58.5 ± 0.76 mg equivalent of gallic acid (GEA) per gram of extract for C. telephiifolia, and 97.57 mg equivalent of gallic acid (GEA) per gram of extract of A. pyrethrum). The antimicrobial activity of the aqueous extracts against three bacterial strains was evaluated on the basis of the inhibition zone using the disk diffusion assay. The aqueous extract of Corrigiola telephiifolia is slightly active on E. coli. At a concentration of extract 100 μg mL-1, the size of the inhibition zone equal to 9 ± 0.06 mm. Whereas S. aureus, E. coli and K. pneumoniae showed a sensitivity to the macerate of Anacyclus pyrethrum at the concentration 100 μg mL-1 of extract with an inhibition zone 16.55 ± 0.6 mm, 14.95 ± 1.25 mm and 10.83 ± 0.96 respectively.

scholarly journals The Impact Resistance of Highly Densified Metal Alloys Manufactured from Gas-Atomized Pre-Alloyed Powders

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 216
Author(s):  
Ramin Rahmani ◽  
Maksim Antonov ◽  
Konda Gokuldoss Prashanth
Keyword(s):  
Physical Vapor Deposition ◽  
Impact Resistance ◽  
Three Dimensional ◽  
Metal Alloys ◽  
Powder Bed ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
3D Printed ◽  
Printed Materials ◽  
The Impact

With the increasing acceleration of three-dimensional (3D) printing (for example, powder bed fusion (PBF)) of metal alloys as an additive manufacturing process, a comprehensive characterization of 3D-printed materials and structures is inevitable. The purpose of this work was to test highly densified materials produced from gas-atomized pre-alloyed metallic powders, namely 316L, Ti6Al4V, AlSi10Mg, CuNi2SiCr, CoCr28Mo6, and Inconel718, under impact conditions. This was done to demonstrate the best possible performance of such materials. Optimized spark plasma sintering (SPS) parameters (pressure, temperature, heating rate, and holding time) are applied as a novel technique of powder metallurgy. The densification level, impact site (imprint) diameter and volume, and Vickers hardness were studied. The comparison of 316L stainless steel (1) sintered by the SPS process, (2) manufactured by PBF process, and (3) coated by the physical vapor deposition (PVD) process (thin layer of TiAlN) was successfully achieved.

scholarly journals In Vitro Coliform Resistance to Bioactive Compounds in Urinary Infection, Assessed in a Lab Catheterization Model

2021 ◽  
Vol 11 (9) ◽  
pp. 4315
Author(s):  
Emanuel Vamanu ◽  
Laura Dorina Dinu ◽  
Cristina Mihaela Luntraru ◽  
Alexandru Suciu
Keyword(s):  
Urinary Tract ◽  
Bioactive Compounds ◽  
Urinary Tract Infections ◽  
Antimicrobial Effect ◽  
Biologically Active ◽  
Bacterial Strains ◽  
E Coli ◽  
Functional Product ◽  
Tract Infections

Bioactive compounds and phenolic compounds are viable alternatives to antibiotics in recurrent urinary tract infections. This study aimed to use a natural functional product, based on the bioactive compounds’ composition, to inhibit the uropathogenic strains of Escherichia coli. E. coli ATCC 25922 was used to characterize the IVCM (new in vitro catheterization model). As support for reducing bacterial proliferation, the cytotoxicity against a strain of Candida albicans was also determined (over 75% at 1 mg/mL). The results were correlated with the analysis of the distribution of biologically active compounds (trans-ferulic acid-268.44 ± 0.001 mg/100 g extract and an equal quantity of Trans-p-coumaric acid and rosmarinic acid). A pronounced inhibitory effect against the uropathogenic strain E. coli 317 (4 log copy no./mL after 72 h) was determined. The results showed a targeted response to the product for tested bacterial strains. The importance of research resulted from the easy and fast characterization of the functional product with antimicrobial effect against uropathogenic strains of E. coli. This study demonstrated that the proposed in vitro model was a valuable tool for assessing urinary tract infections with E. coli.

scholarly journals Design, Synthesis and Biological Evaluation of Novel Benzothiazole Based [1,2,4]Triazolo[4,3-c]quinazoline Derivatives

2020 ◽  
Vol 32 (3) ◽  
pp. 580-586
Author(s):  
Ranjit V. Gadhave ◽  
Bhanudas S. Kuchekar
Keyword(s):  
Biological Evaluation ◽  
Bacterial Strains ◽  
Active Compounds ◽  
Design Synthesis ◽  
Structural Modifications ◽  
E Coli ◽  
Chemical Structures ◽  
Ft Ir ◽  
Antioxidant Agent

A new series of N-(benzo[d]thiazol-2-yl)-[1,2,4]triazolo[4,3-c]quinazoline-5-carboxamide derivatives were synthesized by condensation of [1,2,4]triazolo[4,3-c]quinazoline-5-carboxylate derivatives with substituted benzothiazoles. The chemical structures of the synthesized compounds were confirmed by FT-IR, MS and 1H NMR spectra. Designed triazoloquinazoline derivatives were docked with oxido-reductase enzyme (PDB Code 4h1j) and DNA gyrase enzyme (PDB Code 3g75). Based on high binding affinity score, the best compound were selected for synthesis and subjected to in vitro antioxidant and antibacterial activity. Compounds 7a and 7d were found to be most active compounds as antioxidant agent among this series when compared with ascorbic acid. Compounds 7a, 7d and 7f were found to be most active compounds as an antibacterial agents among this series when compared with ciprofloxacin against bacterial strains such as S. aureus (ATCC 25923), E. coli (ATCC 25922) and P. aeruginosa (ATCC 27853). Study revealed that the most active compounds after structural modifications can be exploited as lead molecules for other pharmacological activities such as anti-inflammatory, anticancer and antidepressant activities.

Antimicrobial Screening, in Silico Studies and QSAR of Chalcone-based 1,4-disubstituted 1,2,3-triazole Hybrids

Drug Research ◽  
2020 ◽  
Author(s):  
Pinki Yadav ◽  
Kashmiri Lal ◽  
Ashwani Kumar
Keyword(s):  
Topoisomerase Ii ◽  
Antimicrobial Properties ◽  
Qsar Model ◽  
Quantitative Structure Activity Relationship ◽  
Binding Modes ◽  
E Coli ◽  
Structure Activity ◽  
In Silico Studies ◽  
Microbial Strains

AbstractThe in vitro antimicrobial properties of some chalcones (1a–1c ) and chalcone tethred 1,4-disubstituted 1,2,3-triazoles (2a–2u) towards different microbial strains viz. Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger and Candida albicans are reported. Compounds 2g and 2u exhibited better potency than the standard Fluconazole with MIC values of 0.0063 µmol/mL and 0.0068 µmol/mL, respectively. Furthermore, molecular docking was performed to investigate the binding modes of two potent compounds 2q and 2g with E. coli topoisomerase II DNA gyrase B and C. albicans lanosterol 14α-demethylase, respectively. Based on these results, a statistically significant quantitative structure activity relationship (QSAR) model was successfully summarized for antibacterial activity against B. subtilis.

scholarly journals Vacuum brazing of Al2O3 and 3D printed Ti6Al4V lap-joints using high entropy driven AlZnCuFeSi filler

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ashutosh Sharma ◽  
Byungmin Ahn
Keyword(s):  
Strength Properties ◽  
Lap Joints ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
3D Printed ◽  
Face Centered ◽  
Alloy Filler

AbstractIn this work, we studied the brazing characteristics of Al2O3 and 3D printed Ti–6Al–4V alloys using a novel equiatomic AlZnCuFeSi high entropy alloy filler (HEAF). The HEAF was prepared by mechanical alloying of the constituent powder and spark plasma sintering (SPS) approach. The filler microstructure, wettability and melting point were investigated. The mechanical and joint strength properties were also evaluated. The results showed that the developed AlZnCuFeSi HEAF consists of a dual phase (Cu–Zn, face-centered cubic (FCC)) and Al–Fe–Si rich (base centered cubic, BCC) phases. The phase structure of the (Cu–Al + Ti–Fe–Si)/solid solution promises a robust joint between Al2O3 and Ti–6Al–4V. In addition, the joint interfacial reaction was found to be modulated by the brazing temperature and time because of the altered activity of Ti and Zn. The optimum shear strength reached 84 MPa when the joint was brazed at 1050 °C for 60 s. The results can be promising for the integration of completely different materials using the entropy driven fillers developed in this study.

scholarly journals Fully coupled electrothermal and mechanical simulation of the production of complex shapes by spark plasma sintering

2021 ◽  
Vol 41 (7) ◽  
pp. 4252-4263
Author(s):  
A. Van der Laan ◽  
R. Epherre ◽  
G. Chevallier ◽  
Y. Beynet ◽  
A. Weibel ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Mechanical Simulation ◽  
Plasma Sintering ◽  
Complex Shapes ◽  
Spark Plasma ◽  
Fully Coupled

scholarly journals Synthesis and Antimicrobial Properties of Highly Cross-Linked pH-Sensitive Hydrogels through Gamma Radiation

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2223
Author(s):  
Moises Bustamante-Torres ◽  
Victor H. Pino-Ramos ◽  
David Romero-Fierro ◽  
Sandra P. Hidalgo-Bonilla ◽  
Héctor Magaña ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Film Formation ◽  
Antimicrobial Properties ◽  
Ph Sensitive ◽  
Scanning Calorimetry ◽  
Polymeric Systems ◽  
E Coli ◽  
High Prevalence

The design of new polymeric systems for antimicrobial drug release focused on medical/surgical procedures is of great interest in the biomedical area due to the high prevalence of bacterial infections in patients with wounds or burns. For this reason, in this work, we present a new design of pH-sensitive hydrogels copolymerized by a graft polymerization method (gamma rays), intended for localized prophylactic release of ciprofloxacin and silver nanoparticles (AgNPs) for potential topical bacterial infections. The synthesized hydrogels were copolymerized from acrylic acid (AAc) and agar. Cross-linked hydrogel film formation depended on monomer concentrations and the degree of radiation used (Cobalt-60). The obtained hydrogel films were characterized by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mechanical testing. The swelling of the hydrogels was evidenced by the influence of their pH-sensitiveness. The hydrogel was loaded with antimicrobial agents (AgNPs or ciprofloxacin), and their related activity was evaluated. Finally, the antimicrobial activity of biocidal-loaded hydrogel was tested against Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) on in vitro conditions.

PHYTO-MEDIATED SYNTHESIS OF SILVER NANOPARTICLES USING AQUEOUS EXTRACT OF „BUGLOSSOIDES PURPUROCAERULEA“ (BORAGINACEAE) AND THEIR BIOACTIVITY

2021 ◽  
Author(s):  
Jelena S. Katanić Stanković ◽  
◽  
Nikola Srećković ◽  
Vladimir Mihailović
Keyword(s):  
Silver Nanoparticles ◽  
Aqueous Extract ◽  
Radical Scavenging ◽  
Antimicrobial Properties ◽  
Bacterial Strains ◽  
Penicillium Species ◽  
Microdilution Method ◽  
Biological Potential ◽  
Vis Spectroscopy

In this study, silver nanoparticles (AgNPs) have been synthesized using the aqueous extract of the aerial parts of B. purpurocaerulea, collected in Serbia. B. purpurocaerulea silver nanoparticles (Bp– AgNPs) synthesis was confirmed using UV-Vis spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The biological potential of synthesized Bp-AgNPs was evaluated in vitro using ABTS assay for determining free radical scavenging potential and microdilution method for analysis of antimicrobial properties. Bp-AgNPs showed high antioxidant activity similar to Bp-extract, comparable to BHT. The synthesized nanoparticles exerted remarkable antibacterial effects, with minimal inhibitory concentration (MIC) values below 20 µg/mL. In the case of some bacterial strains, the results of Bp– AgNPs were comparable or similar to standard antibiotic erythromycin. The antifungal activity of Bp– AgNPs was moderate for most of the used strains. Nevertheless, several fungi were resistant to the NPs action, while two tested Penicillium species were extremely sensitive on Bp-AgNPs with MIC lower than 40 µg/mL. The antimicrobial properties of Bp-AgNPs can be useful for the development of new NPs-containing products.

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