scholarly journals Antimicrobial Effect of Multilayered Carbon Nanotubes on Multi-Drug-Resistant Pseudomonas aeruginosa

2019 ◽  
Author(s):  
Hadis Mousavi ◽  
Hamideh Rouhani Nejad ◽  
Masoud Zandi ◽  
Amir Khodavirdi Pour
Keyword(s):  
Carbon Nanotubes ◽  
Pseudomonas Aeruginosa ◽  
Defense Mechanisms ◽  
Methicillin Resistance ◽  
Antimicrobial Effect ◽  
Inhibitory Effect ◽  
Drug Resistant ◽  
Minimal Inhibitory Concentrations ◽  
Single Walled Cnts ◽  
Walled Cnts

Background: Pseudomonas aeruginosa is the primary cause of infection with impaired defense mechanisms. P. aeruginosa commonly causes nosocomial infections and is the most common pathogen isolated from patients hospitalized for longer than 1 week. We examined the antimicrobial effect of multilayered carbon nanotubes on multi-drug-resistant. Materials and Methods: In this research, 20 clinical isolates collected at Motahari Hospital (Tehran, Iran) were compared with the standard (ATCC 27853) and identified as P. aeruginosa based on biochemical testing. Conventional disk diffusion assay demonstrated the methicillin resistance of the isolates. Minimal inhibitory concentrations for antibiotics and the multilayer CNTs were determined using the microdilution method. Single-walled CNTs were prepared and their efficacy and potential synergism with antibiotics was assessed. Results: Synergism against P. aeruginosa was evident for methicillin + single-walled CNTs. Conclusion: The inhibitory effect of single-walled CNTs and methicillin was synergistic against the growth of P. aeruginosa.

scholarly journals Dispersion of Carbon Nanotubes with “Green” Detergents

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2908
Author(s):  
Kazuo Umemura ◽  
Ryo Hamano ◽  
Hiroaki Komatsu ◽  
Takashi Ikuno ◽  
Eko Siswoyo
Keyword(s):  
Carbon Nanotubes ◽  
Sodium Dodecyl ◽  
Detergent Solution ◽  
Absorbance Spectroscopy ◽  
Fundamental Research ◽  
The Stability ◽  
Single Walled Cnts ◽  
Better Than ◽  
Walled Cnts ◽  
Cnt Suspensions

Solubilization of carbon nanotubes (CNTs) is a fundamental technique for the use of CNTs and their conjugates as nanodevices and nanobiodevices. In this work, we demonstrate the preparation of CNT suspensions with “green” detergents made from coconuts and bamboo as fundamental research in CNT nanotechnology. Single-walled CNTs (SWNTs) with a few carboxylic acid groups (3–5%) and pristine multi-walled CNTs (MWNTs) were mixed in each detergent solution and sonicated with a bath-type sonicator. The prepared suspensions were characterized using absorbance spectroscopy, scanning electron microscopy, and Raman spectroscopy. Among the eight combinations of CNTs and detergents (two types of CNTs and four detergents, including sodium dodecyl sulfate (SDS) as the standard), SWNTs/MWNTs were well dispersed in all combinations except the combination of the MWNTs and the bamboo detergent. The stability of the suspensions prepared with coconut detergents was better than that prepared with SDS. Because the efficiency of the bamboo detergents against the MWNTs differed significantly from that against the SWNTs, the natural detergent might be useful for separating CNTs. Our results revealed that the use of the “green” detergents had the advantage of dispersing CNTs as well as SDS.

Various Nanotube Scaffolds for Cell Proliferation

2009 ◽  
Vol 631-632 ◽  
pp. 181-186 ◽  
Author(s):  
Fumio Watari ◽  
T. Akasaka ◽  
K. Ishikawa ◽  
M. Matsuoka ◽  
E. Hirata ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Cell Proliferation ◽  
Body Fluid ◽  
Biomedical Applications ◽  
Cell Edge ◽  
The One ◽  
Single Walled Cnts ◽  
Cells Cultured ◽  
Walled Cnts ◽  
Multiwalled Cnts

Carbon nanotubes (CNT) and their derivatives with different structure and compositions have unique features. In the present study, cell proliferation was performed on various nanotubes such as single walled CNTs, multiwalled CNTs and imogolite which is nanotubes of aluminosilicate. SEM observation of the growth of osteoblast-like cells cultured on CNTs showed the morphology fully developed for the whole direction, which was different from that extended to the one direction on the usual scaffold. Numerous filopodia were grown from cell edge, extended far long and combined with CNT meshwork. Apatite precipitation in simulated body fluid, affinity for proteins and saccharides, and nanosize meshwork structure with large porosity would be the properties responsible for these cell adhesion and growth. Imogolite showed the similar properties to CNTs. Nanotubes could be the favorable materials for biomedical applications.

scholarly journals Measurement and study of thermophysical properties of nanofluids with carbon nanotubes

2021 ◽  
Vol 2119 (1) ◽  
pp. 012117
Author(s):  
V Ya Rudyak ◽  
G R Dashapilov ◽  
A A Shupik
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Thermophysical Properties ◽  
Weight Concentration ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Single Walled Cnts ◽  
Walled Cnts

Abstract This article is devoted to the study of the thermophysical properties of nanofluids with single-walled and multi-walled carbon nanotubes (CNT). Their weight concentration varied from 0.05 to 0.2%. Nanofluids, based on ethylene glycol and water, were studied. Dispersants were also used. The diffusion of CNT had been systematically investigated by the method of dynamic light scattering and their effective hydrodynamic dimensions were determined. The rheology and viscosity of all nanofluids were studied. It is shown that nanofluids are either pseu-doplastic or viscoplastic. Their rheology changes with increasing CNT concentration and temperature. However, in all cases, the viscosity of nanofluids with single-walled CNTs is signifi-cantly higher than that of nanofluids with multi-walled CNTs. In the last part, the electrical conductivity of all these nanofluids and the dispersants effect on it are investigated.

Controlled Deposition and Applied Field Alignment of Single Walled Carbon Nanotubes for CNT Device Fabrication.

2002 ◽  
Vol 739 ◽  
Author(s):  
Jan Smits ◽  
Buzz Wincheski ◽  
JoAnne Ingram ◽  
Neal Watkins ◽  
Jeff Jordan
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Transport ◽  
Device Fabrication ◽  
Self Assembled Monolayer ◽  
Si Substrates ◽  
Metallic Contacts ◽  
Controlled Deposition ◽  
Walled Carbon Nanotubes ◽  
Single Walled Cnts ◽  
Walled Cnts

ABSTRACTCarbon nanotubes (CNTs) offer great potential for advanced sensing devices due to their unique electronic transport properties. However, a significant obstacle to the realization of practical CNT devices is the formation of controlled, reliable and reproducible CNT to metallic contacts. In this work, a procedure for the deposition and alignment of CNTs onto metallic electrodes using chemically functionalized lithographic patterns is reported. This method uses photo and electron beam lithography to pattern simple Cr/Au thin film circuits on oxidized Si substrates. The circuits are then re-patterned with a self-assembled monolayer (SAM) of 3-aminopropyltriethoxysilane (APTES) to specify desired CNT locations between electrodes. The application of an electric field to the metallic contacts during the deposition of solution suspended single walled CNTs causes alignment of the CNTs in the field direction. This method consistently produces aligned CNTs in the defined locations.

CMOS Compatible Growth of Carbon Nanotubes and Their Application in Field-Effect Transistors

2012 ◽  
Vol 1407 ◽  
Author(s):  
T. Uchino ◽  
G. N. Ayre ◽  
D. C. Smith ◽  
J. L. Hutchison ◽  
C. H. de Groot ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Field Effect ◽  
Defect Density ◽  
Field Effect Transistors ◽  
State Of The Art ◽  
Chemical Vapor ◽  
Radial Breathing Mode ◽  
Metal Catalyst ◽  
Single Walled Cnts ◽  
Walled Cnts

ABSTRACTThe metal-catalyst-free growth of carbon nanotubes (CNTs) using chemical vapor deposition and the application in field-effect transistors (FETs) is presented. The CNT growth process used a 3-nm-thick Ge layer on SiO2 that was subsequently annealed to produce Ge nanoparticles. Raman measurements show the presence of radial breathing mode (RBM) peaks and the absence of the disorder induced D-band, indicating single walled CNTs (SWNTs) with a low defect density. The synthesized CNTs are used to fabricate CNTFETs and the best device has a state-of-the-art on/off current ratio of 3×108 and a steep sub-threshold slope of 110 mV/decade.

scholarly journals Shielding effects in thin films of carbon nanotubes within microwave range

2016 ◽  
Vol 56 (2) ◽  
Author(s):  
Alesia Paddubskaya ◽  
Mikhail Shuba ◽  
Gintaras Valušis ◽  
Polina Kuzhir ◽  
Sergey Maksimenko ◽  
...  
Keyword(s):  
Thin Films ◽  
Carbon Nanotubes ◽  
Microwave Frequency ◽  
Microwave Range ◽  
Different Types ◽  
Em Field ◽  
Shielding Properties ◽  
Single Walled Cnts ◽  
Shielding Effects ◽  
Walled Cnts

The electromagnetic shielding properties of thin films comprising different types of carbon nanotubes (CNTs) were analysed in the microwave frequency range (26–36 GHz). A comparative analysis of the shielding properties was achieved for films based on long and short single-, double- and multi-walled CNTs. The experimental results proved that long-length single-walled CNTs demonstrate the highest interaction with the electromagnetic (EM) field, thereby providing the best shielding efficiency. At the same time, double-walled CNTs demonstrate a higher level of absorption ability (50%) along with the overall high EM shielding efficiency (88%), which makes them attractive for using in nanoelectronics screens as they produce the smallest secondary EM pollution.

Antimicrobial effect of phenazines produced by Pseudomonas aeruginosa isolated from saline soil of Mina River, Algeria

2016 ◽  
Vol 5 (5) ◽  
pp. 187-193
Author(s):  
Hicham Dahah ◽  
Rachid Djibaoui ◽  
Saïd Nemmiche
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Saline Soil ◽  
Antimicrobial Effect ◽  
Diffusion Method ◽  
Gel Chromatography ◽  
Minimal Inhibitory Concentrations ◽  
River Region ◽  
Wide Range

Several strains of environmental Pseudomonas aeruginosa have been used in biotechnology to produce beneficial metabolites in medicine and agriculture. Many secondary metabolites are secreted throughout their growth where phenazines are one among the most known stronger metabolites. The phenazines are antimicrobial substances inhibiting a wide range of pathogenic bacteria. In order to exploit the antimicrobial effect of P. aeruginosa and its pheanzines we do isolate the studied bacteria from saline soil collected from Mina river region (Relizane, Algeria). Ten isolates belonged to Pseudomonas were selected by an antagonistic test, one of isolates was identified as P. aeruginosa and selected for phenazines production. Phenazines were produced using King A broth medium, extracted by ethyl acetate and purified by silica gel chromatography. The antimicrobial activity of crude extract containing phenazines was evaluated by the disc diffusion method against a number of pathogen microorganisms and the minimal inhibitory concentrations (MIC) were determined. The results indicated that the crude phenazines solution was effective against Escherichia coli, Staphylococcus aureus, Bacillus cereus, Shigella sonnei and Candida albicans. The characterization of purified phenazines extract by HPLC showed a peak similar to the standard. The results of this study will contribute in the identification of the potential of phenazines naturally-occurring substances as antimicrobial agents.

FABRICATION OF CARBON NANOTUBE FIELD EFFECT TRANSISTORS WITH OCMC DISPERSED SINGLE-WALLED CARBON NANOTUBES

2010 ◽  
Vol 09 (04) ◽  
pp. 377-381
Author(s):  
KUMAR RAJ ◽  
QING ZHANG ◽  
LIANGYU YAN ◽  
MARY B. CHAN PARK
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Single Walled Carbon Nanotubes ◽  
Oxygen Adsorption ◽  
P Type ◽  
Walled Carbon Nanotubes ◽  
Single Walled Cnts ◽  
Walled Cnts

We report on the fabrication of carbon nanotube field effect transistors (CNTFETs) from dispersed single-walled CNTs using OCMC (O-Carboxymethylchitosan) as the surfactant. The as-prepared devices exhibit p-type as well as ambipolar characteristics due to oxygen adsorption at the metal/nanotube contacts. The Raman scattering from the SWCNTs shows that OCMC disperses CNTs efficiently. Rapid thermal annealing (RTA) at 400°C for 5 min is found to partially remove OCMC from the surface of SWCNTs.

Effect of MoO3 as conditioning catalyst on synthesis of carbon nanotubes

2009 ◽  
Vol 24 (4) ◽  
pp. 1307-1310 ◽  
Author(s):  
Yunfang Liu ◽  
Kenji Takeuchi ◽  
Ki Chul Park ◽  
Hiroyuki Muramatsu ◽  
Tomoyuki Fukuyo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Weight ◽  
Reactive Species ◽  
High Yield ◽  
Layer Number ◽  
Yield Formation ◽  
Synthesis Of Carbon Nanotubes ◽  
Reactive Hydrocarbon ◽  
Single Walled Cnts ◽  
Walled Cnts

The effect of nonsupported MoO3 as a conditioning catalyst on the preparation of carbon nanotubes (CNTs) using a common main catalyst Fe/MgO was investigated. Without using MoO3, only single-walled CNTs were produced at low yield. In contrast, the use of MoO3 provided single-walled and double-walled CNTs at high yield. The MoO3 conditioning catalyst enhances not only the yield but also the diameter and layer number of CNTs. The higher yield formation of more layered CNTs with larger diameter would be attributed to the preproduction of reactive hydrocarbon species by the conditioning catalyst and their growth to larger molecular-weight reactive species.

Sign in / Sign up

Export Citation Format

Share Document