scholarly journals High Performance Conducting Nanocomposites Polyaniline (PANI)-CuO with Enhanced Antimicrobial Activity for Biomedical Applications

Author(s):  
Supriya Vyas ◽  
◽  
Ashutosh Shukla ◽  
Sugam J Shivhare ◽  
Vivekanand S Bagal ◽  
...  
Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 340
Author(s):  
Kitherian Sahayaraj ◽  
Balakrishnan Saranya ◽  
Samy Sayed ◽  
Loko Yêyinou Laura Estelle ◽  
Koilraj Madasamy

The foam produced by nymphs of Poophilus costalis on eleven different host plants belonging to eight families on St. Xavier’s College campus in India was studied over five months. The chemical composition and antimicrobial activity of these biofoams were investigated. The results revealed that P. costalis preferred Theporsia purpurea and Mimosa pudica for laying their eggs and producing foam, over the other tested plants. P. costalis produce their foam on either nodes or internodes on monocotyledons (30%) (p < 0.05), whereas on dicotyledons, they produce more foam on the stems (63.8%) than on the leaves (6.2%) (p < 0.01). The number of nymphs in each piece of foam from P. costalis varied from 1 to 3 (mean = 1.8 per plant). They produced their foam (5.7 to 45.2 cm) from the ground level on a plant. The length and breadth of a piece of foam ranged from 1.0 to 3.9 cm and 0.6 to 4.7 cm, respectively. The foam tended to be cooler than the environment. Qualitative profiling showed that the foam consists of carbohydrates, including maltose; trypsin; amino acids; protease. The foam was also analyzed using a spectrophotometer, Fourier transform infrared spectroscopy (FT-IR), gas chromatography–mass spectroscopy (GC-MS), and high-performance liquid chromatography (HPLC). The antimicrobial activity of the biofoam was the greatest against Staphylococcus aureus, the growth of which was reduced by 55.9 ± 3.9%, suggesting that the foam could be used as an antimicrobial product. However, no activities were observed against Fusarium oxysporum and Candida albicans.


Author(s):  
amal aboelnaga ◽  
talaat Meaz ◽  
amany M elnahrawy

Abstract The aim of this study is to investigate the effect of different doses of Velosef in magnesium silica/chitosan nanocomposite in terms of structural, morphology, optical properties, and bioactivity. Loading Velosef in fine-sized magnesium silica/chitosan is an efficient engineering approach for drug delivery. The sol-gel process was used to prepare magnesium silica fine-sized before being blended into chitosan matrix, which acts as a potential morphogenetic biomaterial. The Velosef/magnesium silica/chitosan nanocomposites were characterized by XRD, TEM, SEM, FTIR, UV-absorption, and antimicrobial studies. The XRD was characteristic of the crystallinity degree of the MgO-SiO2/chitosan/Velosef nanocomposites with three maximum peaks at 26.37°, 33.34o, 36.9°. FTIR results indicated the structural change occurred with the Velosef sol-gel polymerization process. UV-absorbance reveals that the MgO-SiO2/chitosan nanocomposite appeared a high performance for loading Velosef at two absorption bands at 253 and 347 nm. The MgO-SiO2/Chitosan/Velosef nanocomposites showed considerable antimicrobial activity in opposition to the tested representative microorganisms. The maximum antimicrobial activity was obtained with MgO-SiO2/Chitosan against both Escherichia coli and Candida albicans (37 mm), while the minimum antimicrobial activity (30 mm) was recorded against B. mycoides and E. coli with control.


2019 ◽  
Vol 28 (07) ◽  
pp. 1950110 ◽  
Author(s):  
K. Hayatleh ◽  
S. Zourob ◽  
R. Nagulapalli ◽  
S. Barker ◽  
N. Yassine ◽  
...  

This paper describes a high-performance impedance measurement circuit for the application of skin impedance measurement in the early detection of skin cancer. A CMRR improvement technique has been adopted for OTAs to reduce the impact of high-frequency common mode interference. A modified three-OTA instrumentation amplifier (IA) has been proposed to help with the impedance measurement. Such systems offer a quick, noninvasive and painless procedure, thus having considerable advantages over the currently used approach, which is based upon the testing of a biopsy sample. The sensor has been implemented in 65[Formula: see text]nm CMOS technology and post-layout simulations confirm the theoretical claims we made and sensor exhibits sensitivity. Circuit consumes 45[Formula: see text]uW from 1.5[Formula: see text]V power supply. The circuit occupies 0.01954[Formula: see text]mm2 silicon area.


2019 ◽  
Vol 70 (4) ◽  
pp. 323-329 ◽  
Author(s):  
Gergely Sámuel Bartha ◽  
Gergő Tóth ◽  
Péter Horváth ◽  
Eszter Kiss ◽  
Nóra Papp ◽  
...  

Introduction Several Aristolochia species were used as medicinal herb across Europe and in recent years, their antimicrobial activity has also been investigated. Materials and methods In this study, A. clematitis was selected to evaluate the aristolochic acids I and II (AA I and AA II) concentrations and the antimicrobial activity of methanol, hexane, butanol, and ethyl acetate extracts of the root, stem, leaf, root, and fruit. AA I and AA II contents were measured by a validated high-performance liquid chromatography–ultraviolet method. Results Each fraction of the plant contained AA I and AA II and the root was found to have the highest contents of AA I (1.09%) and AA II (0.7454%). The minimum inhibitory concentrations of all extracts were determined by standard microdilution method. The fruit’s extracts showed the most efficient antimicrobial effect against both methicillin sensitive and resistant Staphylococcus aureus strains. Conclusion Correlation between the AA I and AA II concentrations and the antimicrobial effect was not found.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3641
Author(s):  
Beata Kaczmarek ◽  
Olha Mazur

Collagen-based biomaterials constitute one of the most widely studied types of materials for biomedical applications. Low thermal and mechanical parameters are the main disadvantages of such structures. Moreover, they present low stability in the case of degradation by collagenase. To improve the properties of collagen-based materials, different types of cross-linkers have been researched. In recent years, phenolic acids have been studied as collagen modifiers. Mainly, tannic acid has been tested for collagen modification as it interacts with a polymeric chain by strong hydrogen bonds. When compared to pure collagen, such complexes show both antimicrobial activity and improved physicochemical properties. Less research reporting on other phenolic acids has been published. This review is a summary of the present knowledge about phenolic acids (e.g., tannic, ferulic, gallic, and caffeic acid) application as collagen cross-linkers. The studies concerning collagen-based materials with phenolic acids are summarized and discussed.


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