scholarly journals Characterization of biological membranes by physical chemical methods. Progress report, June 1, 1974--May 31, 1975. [Human erythrocytes and E. coli cells]

1975 ◽  
Author(s):  
A. K. Solomon
Keyword(s):  
Biological Membranes ◽  
Progress Report ◽  
Human Erythrocytes ◽  
Chemical Methods ◽  
E Coli ◽  
Physical Chemical

scholarly journals A GREEN AND SIMPLE SYNTHESIS OF CHITOSAN/Ag NANOCOMPOSITES AND STUDY FOR THEIR ANTIBACTERIAL ACTIVITY ON STAPHYLOCOCCUS AUREUS AND ESCHERICHIA COLI

2018 ◽  
Vol 56 (2A) ◽  
pp. 89-98
Author(s):  
Tran Thi Bich Quyen
Keyword(s):  
Antimicrobial Activity ◽  
Average Particle Size ◽  
Cost Effective ◽  
Simple Approach ◽  
Average Particle ◽  
Chemical Methods ◽  
Green Method ◽  
E Coli ◽  
Physical Chemical ◽  
Efficient Route

A green and simple approach has been successfully developed to synthesize chitosan/Ag nanocomposites using kumquat extract as a biological reducing agent. It indicates to be an eco-friendly and green method for the synthesis providing a cost effective and an efficient route for the chitosan/Ag nanocomposites’ synthesis. The prepared chitosan/Ag nanocomposites have been characterized by UV-vis, TEM, FTIR, and XRD. Result showed those chitosan/Ag nanocomposites have been obtained with average particle size ~15-25 nm. Moreover, the synthesized chitosan/Ag nanocomposites also showed their efficient antimicrobial activity against S. aureus and E. coli. The chitosan/Ag nanocomposite was found to have significantly higher antimicrobial activity than its components at their respective concentrations. The presence of a small percentage (2.5 %, w/w) of metal nanoparticles in the nanocomposite was enough to significantly enhance inactivation of S. aureus and E. coli as compared with unaltered chitosan. Thus, this eco-friendly method could be a competitive alternative to the conventional physical/chemical methods used for the synthesis of chitosan/Ag nanocomposites. Since, it has a potential to use in biomedical and cosmetic applications. 

Characterization of pili associated with Escherichia coli O18ac

1980 ◽  
Vol 29 (2) ◽  
pp. 685-691 ◽  
Author(s):  
P Wevers ◽  
R Picken ◽  
G Schmidt ◽  
B Jann ◽  
K Jann ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Stool Sample ◽  
Human Erythrocytes ◽  
Chemical Analyses ◽  
E Coli

A strain of Escherichia coli O18ac isolated from the stool sample of a patient with diarrhea was found to agglutinate human erythrocytes. From the results presented it is suggested that this hemagglutination is mediated by pili. Isolated pilus preparations agglutinated human erythrocytes, whereas pilus-negative mutants did not. The serological and chemical analyses indicate that the pili associated with E. coli O18ac are distinct from other types found with E. coli.

EXFOLIATION AND CHARACTERIZATION OF LAYERED SILICATE MINERALS: A REVIEW

2014 ◽  
Vol 21 (02) ◽  
pp. 1430001 ◽  
Author(s):  
FEIFEI JIA ◽  
SHAOXIAN SONG
Keyword(s):  
Layered Silicate ◽  
Influential Factors ◽  
Dramatic Improvement ◽  
Chemical Methods ◽  
Silicate Minerals ◽  
Physical Chemical ◽  
Physical And Chemical

Exfoliated silicate minerals have attracted great attentions because of the dramatic improvement in properties. This paper highlights the preparation of exfoliated silicate minerals, including physical, chemical, mixed physical and chemical methods. The mechanisms by which silicates are exfoliated and the important influential factors are also summarized. Finally, the instrumental techniques to characterize the exfoliated structure and exfoliation degree are presented.

Characterization of greywater sources on the base of organic content and microbial quality

2014 ◽  
Vol 5 (1) ◽  
pp. 35-40
Author(s):  
N. Boros ◽  
A. Petrányi ◽  
D. Kocsis ◽  
I. Bodnár
Keyword(s):  
Potable Water ◽  
Water Source ◽  
Organic Content ◽  
Contaminated Water ◽  
High Similarity ◽  
E Coli ◽  
Physical Chemical ◽  
Plate Counts

Abstract The recycling of greywater for non-potable water applications, such as toilet flushing or irrigation, is a potential solution to reduce potable water consumption. To estimate the quality of raw greywater samples, we measured several physical, chemical and biological parameters. We used Hygiene Monitor test kits to determine microbiological presence in the samples. The greywater samples showed a high variability for all the measured parameters. In general, we found that greywater sources had lightly alkaline character with a considerable inorganic and organic content. About half of the analyzed samples can be characterized as highly contaminated water source with organic substance. The average BOD5 and DOC values of greywater samples were 429 ± 410 mg l−1 and 341 ± 348 mg l−1. The samples showed high similarity concerning the total plate counts parameter (range from 5 to 6 log10 cfu ml−1). Among the three greywater sources, the samples from dish sources showed the lowest coliform content (3.9 log10 cfu ml−1) and the bath samples were contaminated with coliforms to the highest degree (4.9 log10 cfu ml−1). The results of E. coli contamination tests proved that all greywater sources can be contaminated with pathogen bacteria, consequently the treatment before reuse of greywater is indispensable.

A Research on Synthesis of Microorganism Template Nano-Selenium Material

2013 ◽  
Vol 443 ◽  
pp. 639-642
Author(s):  
Ya Li Zhang ◽  
Wei Xia ◽  
Ai Hua Ren
Keyword(s):  
Low Cost ◽  
Synthetic Methods ◽  
X Ray Diffraction ◽  
Environmental Friendliness ◽  
Preparation Methods ◽  
X Ray ◽  
E Coli ◽  
Physical Chemical ◽  
Harsh Conditions

At present there are various kinds of synthetic methods of nanomaterials including physical, chemical and composite method derived from the former two kinds. However, these preparation methods require harsh conditions and produce low yield. Besides, they cause environmental pollution easily. Therefore the microorganism template synthesis is favored highly due to its rich resources, low cost and availability, environmental friendliness and unique configuration and high morphology repeatability. In this thesis E. coli strains are successfully adopted as the template to synthesize nanoselenium material. Such inspection methods as scanning electron microscope, X-ray diffraction and ultraviolet are used for the characterization of samples. It aims to explore a new synthetic green way for nanoselenium material.

Transmission Electron Microscopy of Protein Macromolecules

1971 ◽  
Vol 29 ◽  
pp. 424-425
Author(s):  
Henry S. Slayter
Keyword(s):  
Biological Systems ◽  
Metal Vapor ◽  
Resolving Power ◽  
Electron Microscopic ◽  
Chemical Methods ◽  
Molecular Weights ◽  
The Past ◽  
Physical Chemical ◽  
Transmission Electron

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid-beta M1-42

2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Amyloid Beta ◽  
Western Blots ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Set Up ◽  
Short Time

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.

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