Generation of silver titania nanoparticles from an Ag–Ti alloy via picosecond laser ablation and their antibacterial activities

RSC Advances ◽  
2015 ◽  
Vol 5 (89) ◽  
pp. 72981-72994 ◽  
Author(s):  
Abubaker Hamad ◽  
Lin Li ◽  
Zhu Liu ◽  
Xiang Li Zhong ◽  
Hong Liu ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Picosecond Laser ◽  
Antibacterial Activities ◽  
Titania Nanoparticles ◽  
Ti Alloy ◽  
First Time

In this work, a bulk Ti/Ag alloy was used, for the first time, to produce Ag–TiO2 compound nanoparticles using picosecond laser ablation in deionised water.

Chemical Constituents and Antibacterial Activity of Cissus Aralioides.

2020 ◽  
Vol 17 ◽  
Author(s):  
Balogun Olaoye Solomon ◽  
Ajayi Olukayode Solomon ◽  
Owolabi Temitayo Abidemi ◽  
Oladimeji Abdulkarbir Oladele ◽  
Liu Zhiqiang
Keyword(s):  
Plant Extract ◽  
Chemical Constituents ◽  
Ethyl Acetate Fraction ◽  
Antibacterial Activities ◽  
Sub Saharan Africa ◽  
Chromatographic Purification ◽  
Whole Plant ◽  
Sub Saharan ◽  
First Time

: Cissus aralioides is a medicinal plant used in sub-Saharan Africa for treatment of infectious diseases; however the chemical constituents of the plant have not been investigated. Thus, in this study, attempt was made at identifying predominant phytochemical constituents of the plant through chromatographic purification and silylation of the plant extract, and subsequent characterization using spectroscopic and GC-MS techniques. The minimum inhibitory concentration (MICs) for the antibacterial activities of the plant extract, chromatographic fractions and isolated compounds were also examined. Chromatographic purification of the ethyl acetate fraction from the whole plant afforded three compounds: β-sitosterol (1), stigmasterol (2) and friedelin (3). The phytosterols (1 and 2) were obtained together as a mixture. The GC-MS analysis of silylated extract indicated alcohols, fatty acids and sugars as predominant classes, with composition of 24.62, 36.90 and 26.52% respectively. Results of MICs indicated that friedelin and other chromatographic fractions had values (0.0626-1.0 mg/mL) comparable with the standard antibiotics used. Characterization of natural products from C. aralioides is being reported for the first time in this study.

scholarly journals Facile Green, Room-Temperature Synthesis of Gold Nanoparticles Using Combretum erythrophyllum Leaf Extract: Antibacterial and Cell Viability Studies against Normal and Cancerous Cells

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 893
Author(s):  
Olufunto T. Fanoro ◽  
Sundararajan Parani ◽  
Rodney Maluleke ◽  
Thabang C. Lebepe ◽  
Jose R. Varghese ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Cell Viability ◽  
Leaf Extract ◽  
Room Temperature ◽  
Klebsiella Oxytoca ◽  
Cost Effective ◽  
Average Diameter ◽  
Antibacterial Activities ◽  
Inhibition Concentration ◽  
First Time

We herein report a facile, green, cost-effective, plant-mediated synthesis of gold nanoparticles (AuNPs) for the first time using Combretum erythrophyllum (CE) plant leaves. The synthesis was conducted at room temperature using CE leaf extract serving as a reducing and capping agent. The as-synthesized AuNPs were found to be crystalline, well dispersed, and spherical in shape with an average diameter of 13.20 nm and an excellent stability of over 60 days. The AuNPs showed broad-spectrum antibacterial activities against both pathogenic Gram-positive (Staphylococcus epidermidis (ATCC14990), Staphylococcus aureus (ATCC 25923), Mycobacterium smegmatis (MC 215)) and Gram-negative bacteria (Proteus mirabilis (ATCC 7002), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13822), Klebsiella oxytoca (ATCC 8724)), with a minimum inhibition concentration of 62.5 µg/mL. In addition, the as-synthesized AuNPs were highly stable with exceptional cell viability towards normal cells (BHK- 21) and cancerous cancer cell lines (cervical and lung cancer).

Defining the molecular structure of teixobactin analogues and understanding their role in antibacterial activities

2017 ◽  
Vol 53 (12) ◽  
pp. 2016-2019 ◽  
Author(s):  
Anish Parmar ◽  
Stephen H. Prior ◽  
Abhishek Iyer ◽  
Charlotte S. Vincent ◽  
Dorien Van Lysebetten ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Antibacterial Activities ◽  
Key Residues ◽  
First Time

In this work, we have for the first time defined the molecular structure of seven teixobactin analogues through the variation of the d/l configuration of its key residues.

Preparation and Characterization of Chitosan-Casein Phosphopeptides Biocomposite Coatings on the Medical Titanium Alloy

2011 ◽  
Vol 480-481 ◽  
pp. 1065-1069
Author(s):  
Bin Liu ◽  
Lin Wang ◽  
Yin Zhong Bu ◽  
Sheng Rong Yang ◽  
Jin Qing Wang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Attenuated Total Reflectance ◽  
Ti Alloy ◽  
Force Microscopy ◽  
Implant Materials ◽  
Atomic Force ◽  
Casein Phosphopeptides ◽  
Potential Applications ◽  
First Time

Titanium (Ti) and its alloys have been applied in orthopedics as one of the most popular biomedical metallic implant materials. In this work, to enhance the bioactivity, the surface of Ti alloy pre-modified by silane coupling agent and glutaraldehyde was covalently grafted with chitosan (CS) via biochemical multistep self-assembled method. Then, for the first time, the achieved surface was further immobilized with casein phosphopeptides (CPP), which are one group of bioactive peptides released from caseins in the digestive tract and can facilitate the calcium adsorption and usage, to form CS-CPP biocomposite coatings. The structure and composition of the fabricated coatings were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and atomic force microscopy (AFM). As the experimental results indicated, multi-step assembly was successfully performed, and the CS and CPP were assembled onto the Ti alloy surface orderly. It is anticipated that the Ti alloys modified by CS-CPP biocomposite coatings will find potential applications as implant materials in biomedical fields.

scholarly journals Studies on linear, nonlinear optical and excited state dynamics of silicon nanoparticles prepared by picosecond laser ablation

AIP Advances ◽  
2015 ◽  
Vol 5 (12) ◽  
pp. 127127 ◽  
Author(s):  
Syed Hamad ◽  
G. Krishna Podagatlapalli ◽  
R. Mounika ◽  
S. V. S. Nageswara Rao ◽  
A. P. Pathak ◽  
...  
Keyword(s):  
Excited State ◽  
Laser Ablation ◽  
Nonlinear Optical ◽  
Silicon Nanoparticles ◽  
Picosecond Laser ◽  
Excited State Dynamics

scholarly journals Sesquiterpenoids From the Antarctic Fungus Pseudogymnoascus sp. HSX2#-11

2021 ◽  
Vol 12 ◽  
Author(s):  
Ting Shi ◽  
Xiang-Qian Li ◽  
Li Zheng ◽  
Ya-Hui Zhang ◽  
Jia-Jia Dai ◽  
...  
Keyword(s):  
Pathogenic Fungi ◽  
Antibacterial Activities ◽  
Aeromonas Salmonicida ◽  
Systematic Research ◽  
Cytotoxic Activities ◽  
Hepg2 Cell Lines ◽  
New Compounds ◽  
The Antarctic ◽  
First Time ◽  
Hepatoma Hepg2

The fungal strains Pseudogymnoascus are a kind of psychrophilic pathogenic fungi that are ubiquitously distributed in Antarctica, while the studies of their secondary metabolites are infrequent. Systematic research of the metabolites of the fungus Pseudogymnoascus sp. HSX2#-11 led to the isolation of six new tremulane sesquiterpenoids pseudotremulanes A–F (1–6), combined with one known analog 11,12-epoxy-12β-hydroxy-1-tremulen-5-one (7), and five known steroids (8–12). The absolute configurations of the new compounds (1–6) were elucidated by their ECD spectra and ECD calculations. Compounds 1–7 were proved to be isomeride structures with the same chemical formula. Compounds 1/2, 3/4, 1/4, and 2/3 were identified as four pairs of epimerides at the locations of C-3, C-3, C-9, and C-9, respectively. Compounds 8 and 9 exhibited cytotoxic activities against human breast cancer (MDA-MB-231), colorectal cancer (HCT116), and hepatoma (HepG2) cell lines. Compounds 9 and 10 also showed antibacterial activities against marine fouling bacteria Aeromonas salmonicida. This is the first time to find terpenoids and steroids in the fungal genus Pseudogymnoascus.

scholarly journals Developments of Space Debris Laser Ranging Technology Including the Applications of Picosecond Lasers

2021 ◽  
Vol 11 (21) ◽  
pp. 10080
Author(s):  
Haifeng Zhang ◽  
Mingliang Long ◽  
Huarong Deng ◽  
Shaoyu Cheng ◽  
Zhibo Wu ◽  
...  
Keyword(s):  
Space Debris ◽  
New Technologies ◽  
Pulse Repetition Frequency ◽  
Average Power ◽  
Picosecond Laser ◽  
Laser Ranging ◽  
Telescope Array ◽  
High Pulse ◽  
First Time ◽  
532 Nm

Debris laser ranging (DLR) is receiving considerable attention as an accurate and effective method of determining and predicting the orbits of space debris. This paper reports some technologies of DLR, such as the high pulse repetition frequency (PRF) laser pulse, large-aperture telescope, telescope array, multi-static stations receiving signals. DLR with a picosecond laser at the Shanghai Astronomical Observatory is also presented. A few hundred laps of space debris laser-ranging measurements have been made. A double-pulse picosecond laser with an average power of 4.2 W, a PRF of 1 kHz, and a wavelength of 532 nm has been implemented successfully in DLR, it’s the first time that DLR technology has reached a ranging precision at the sub-decimeter level. In addition, the characteristics of the picosecond-pulse-width laser transmission with the advantages of transmission in laser ranging were analyzed. With a mode of the pulse-burst picosecond laser having high average power, the DLR system has tracked small debris with a radar cross-section (RCS) of 0.91 m2 at a ranging distance up to 1726.8 km, corresponding to an RCS of 0.1 m2 at a distance of 1000 km. These works are expected to provide new technologies to further improve the performance of DLR.

Sign in / Sign up

Export Citation Format

Share Document