Toxicity assessment of 255 chemicals to pure cultured nitrifying bacteria using biosensor

2002 ◽  
Vol 46 (11-12) ◽  
pp. 331-335 ◽  
Author(s):  
Y. Tanaka ◽  
K. Taguchi ◽  
H. Utsumi
Keyword(s):  
Functional Group ◽  
Synergistic Effects ◽  
Toxicity Assessment ◽  
Inhibition Test ◽  
Nitrifying Bacteria ◽  
Inhibition Rate ◽  
Thioamide Group ◽  
Chemical Contaminant ◽  
Mixed Samples

The bioassay has been attracting attention as a method of toxicity assessments of micropollutants in the environment. In this study, we report the characteristics (selectivity and sensitivity) of the nitrifying bacteria biosensor for 255 kinds of chemicals as a model of chemical contaminant in the environment and the results of evaluation of mixed samples of several substances. In the nitrifying bacteria respiration inhibition test using the biosensor, 56 chemicals were detected. It was found that this biosensor is especially sensitive to seven chemicals that have a thiocarbonyl functional group (>C=S), such as a thioamide group of thiocarbamate group. These chemicals are considered to specifically inhibit AMO by chelation of copper. The samples consisted of a mixture of seven types of anilines that inhibit respiration in the bacteria, a mixture of five types of chlorophenols, and a mixture of eight types of substances that contain thiocarbonyl groups were examined. All of the mixed samples inhibited the respiration of the nitrifying bacteria more than 10% by the inhibition rate, and observed a synergistic effects of the substances in the samples.

scholarly journals Evaluation of antimicrobial and anticancer activity of Rosemary Rosmarinus oficinalis leaves extracts on pathogenic bacteria and cancer cell lines

2013 ◽  
Vol 7 (3) ◽  
pp. 3-15
Author(s):  
Mahfoodha A. Umran ◽  
AssAshwaq A. Kadhemma ◽  
Jinan MJ. Al-Saffar ◽  
Ekbal Razwqy
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Pathogenic Bacteria ◽  
Synergistic Effects ◽  
Inhibition Zone ◽  
Mammary Adenocarcinoma ◽  
Rosemary Extract ◽  
Inhibition Rate ◽  
E Coli ◽  
Mueller Hinton Agar

The present study was carried out to detect the active constitutions extracted from Rosmarinus oficinalis leaves by 70% methanol, the dried weight of aqueous extract (F1) were 12%(w:w) contain polyphenols represented by phenols, flavonoids and coumarins as a major compounds , while the dried weight of organic extract, [chloroform(F2)] was 2.8%(w:w) represented as terpenoids, tannins and coumarins detected by qualitative chemical analysis. Antimicrobial activity of Polyphenols and terpenoids were tested against four pathogenic bacteria isolates including: Escherichia coli; Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus cereus ,which grown on Mueller Hinton agar (MHA) plates and then treated with different concentrations of rosemary extract (F1) and (F2) ranged from 0.15-1.2mg/ml, the results revealed that the higher inhibition zone obtained by F1 were 35mm in S. aureus, 24mm in B. cereus and lowest inhibition were 16mm in E. coli and P. aeruginosa at concentration 1.2mg/ml, and the inhibition were depends on extract concentrations. The MIC value of F1 was 600 µg/ml against S. aureus, 1200 µg/ml against B. cereus and 2400 µg/ml against E. coli and P. aeruginosa, while the MICS values of F2 were 2400 µg/ml against S. aureus and P. aeruginosa, and 4800 µg/ml against E. coli and B. cereus. Furthermore calculating index fractional inhibitory concentration (∑FIC) of rosemary extracts (F1 or/and F2), the ∑FICA ranged from synergistic to additional on E. coli and P. aeruginosa respectively, antagonistic on S. aueras and B. cereus, while the ∑FICB index showed synergistic effects on all tested organisms except the additional effect on P. aeurginosa on the basis of resultant zone of inhibition. The anticancer effects of (F1) were used on three cell lines, human larynx epidermoid carcinoma (Hep-2), mammary adenocarcinoma (AMN-3), rhabdomyosarcoma (RD) and one normal cell line, Rat embryo fibroblast (REF) at different concentrations ranged from 62.5-1000 µg/ml. The highest inhibition rate (IR) was 82.41%, 85% on RD, 52.62%, 75.48% on Hep2, 39.14% and 49.75% on AMN-3 at concentrations 500 and 1000µg/ml after 72h exposure time respectively, while IR of Ref cell line exhibit low inhibition rate ranging from 5.8 to 15.7% after 72h in the same conditions.

Morphology of High-Performance Rigid-Rod Polymer Fibers and Molecular Composites

1989 ◽  
Vol 47 ◽  
pp. 338-339
Author(s):  
W.W. Adams ◽  
S. J. Krause
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Liquid Crystalline ◽  
Molecular Level ◽  
Synergistic Effects ◽  
Tensile Modulus ◽  
Commercial Development ◽  
The Matrix ◽  
Molecular Composites ◽  
Rigid Rod

Rigid-rod polymers such as PBO, poly(paraphenylene benzobisoxazole), Figure 1a, are now in commercial development for use as high-performance fibers and for reinforcement at the molecular level in molecular composites. Spinning of liquid crystalline polyphosphoric acid solutions of PBO, followed by washing, drying, and tension heat treatment produces fibers which have the following properties: density of 1.59 g/cm3; tensile strength of 820 kpsi; tensile modulus of 52 Mpsi; compressive strength of 50 kpsi; they are electrically insulating; they do not absorb moisture; and they are insensitive to radiation, including ultraviolet. Since the chain modulus of PBO is estimated to be 730 GPa, the high stiffness also affords the opportunity to reinforce a flexible coil polymer at the molecular level, in analogy to a chopped fiber reinforced composite. The objectives of the molecular composite concept are to eliminate the thermal expansion coefficient mismatch between the fiber and the matrix, as occurs in conventional composites, to eliminate the interface between the fiber and the matrix, and, hopefully, to obtain synergistic effects from the exceptional stiffness of the rigid-rod molecule. These expectations have been confirmed in the case of blending rigid-rod PBZT, poly(paraphenylene benzobisthiazole), Figure 1b, with stiff-chain ABPBI, poly 2,5(6) benzimidazole, Fig. 1c A film with 30% PBZT/70% ABPBI had tensile strength 190 kpsi and tensile modulus of 13 Mpsi when solution spun from a 3% methane sulfonic acid solution into a film. The modulus, as predicted by rule of mixtures, for a film with this composition and with planar isotropic orientation, should be 16 Mpsi. The experimental value is 80% of the theoretical value indicating that the concept of a molecular composite is valid.

A new model of synergistic effects of alcohol and high-fat diet on hepatic injury

2010 ◽  
Vol 48 (01) ◽  
Author(s):  
E Gäbele ◽  
K Dostert ◽  
C Dorn ◽  
C Hellerbrand
Keyword(s):  
High Fat Diet ◽  
Hepatic Injury ◽  
Synergistic Effects ◽  
High Fat ◽  
New Model
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