scholarly journals Influence of TiO2 Nanoparticles on the Resistance of Cementitious Composite Materials to the Action of Bacteria

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1074
Author(s):  
Andreea Hegyi ◽  
Adrian-Victor Lăzărescu ◽  
Henriette Szilagyi ◽  
Elvira Grebenişan ◽  
Jana Goia ◽  
...  
Keyword(s):  
Tio2 Nanoparticles ◽  
Cementitious Composite ◽  
Zone Of Inhibition ◽  
Composite Matrix ◽  
Potential Health ◽  
Gram Positive Bacteria ◽  
Low Concentrations ◽  
Building Surfaces ◽  
Inhibition Studies ◽  
Material Durability

The formation of biofilms on cementitious building surfaces can cause visible discoloration and premature deterioration, and it can also represent a potential health threat to building occupants. The use of embedded biofilm-resistant photoactivated TiO2 nanoparticles at low concentrations in the cementitious composite matrix is an effective method to increase material durability and reduce maintenance costs. Zone of inhibition studies of TiO2-infused cementitious samples showed efficacy toward both Gram-negative and Gram-positive bacteria.

scholarly journals Rheological and Textural Properties of Apple Pectin-Based Composite Formula with Xanthan Gum Modification for Preparation of Thickened Matrices with Dysphagia-Friendly Potential

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 873
Author(s):  
Huaiwen Yang ◽  
Chai-Chun Tsai ◽  
Jung-Shiun Jiang ◽  
Chi-Chung Hua
Keyword(s):  
Storage Modulus ◽  
Water Consumption ◽  
Xanthan Gum ◽  
Loss Modulus ◽  
Textural Properties ◽  
Apple Pectin ◽  
Composite Matrix ◽  
Low Concentrations ◽  
Composite Formula

Modifying the consistency of a given edible fluid matrix by incorporating food thickeners is a common nursing remedy for individuals with dysphagia when adequate water consumption is a concern. As apple pectin (AP) offers nutraceutical benefits, properly formulated apple pectin (AP)-based thickeners featuring xanthan gum (XG) can be superior candidates for preparation of dysphagia-friendly matrices (DFMs). Our recruited DFMs exhibit fluid-like behavior (loss modulus > storage modulus, G” > G’) at lower AP concentrations (2 and 5%, w/w); they turn into weak/critical gels (G’ ≈ G”) as the concentration becomes higher (9%). In contrast, XG-DFMs display gel-like attributes with G’ > G”, even at rather low concentrations (<1%) and become more resistant to sugar, Na+, and Ca2+ modifications. The composite matrix of AP1.8XG0.2 (constraint at 2%) exhibits a confined viscosity of 278 ± 11.7 mPa∙s, which is considered a DFM, in comparison to only AP- or XG-thickened ones. The hardness measurements of XG0.6 and AP1.2XG0.8 are 288.33 ± 7.506 and 302.00 ± 9.849 N/m2, respectively, which potentially represent a promising formulation base for future applications with DFMs; these textural values are not significantly different from a commercially available product (p > 0.05) for dysphagia nursing administrations.

Optimization of Silver Nanoparticles Production using Aspergillus niger and Study of Antimicrobial Activity

2021 ◽  
Vol 12 (4) ◽  
pp. 2383-2388
Author(s):  
Suguna Selvakumaran ◽  
Kayathri Marimuthu ◽  
Thiruvany Poopalan ◽  
Kalaiyarasi Tamil Selvan ◽  
Nozieana Khairuddin
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Aspergillus Niger ◽  
Culture Supernatant ◽  
Gram Negative Bacteria ◽  
Mixing Ratio ◽  
Zone Of Inhibition ◽  
Gram Positive Bacteria ◽  
Physiochemical Parameters ◽  
Uv Visible

Silver nanoparticles have attracted high attention worldwide for their various applications. The physiochemical parameters such as temperature, media, mixing ratio affect the rate of synthesis of silver nanoparticles and their yield. Thus, optimization of these physiochemical parameters is needed to enhance the production of silver nanoparticles. In this study, silver nanoparticles were synthesized using Aspergillus niger culture supernatant. The produced silver nanoparticles were characterized using UV-visible Spectrophotometer at 200 nm to 700 nm, which had a peak at 450 nm, indicates the formation of silver nanoparticles. It was found that Sabouraud Dextrose Broth (SDB) as optimum media, 40 ml of supernatant and 10 ml of silver nitrate as optimum mixing ratio and 65°C as optimum temperature to produce silver nanoparticles. The optimized silver nanoparticles were subjected to antimicrobial activity, and it was found that it is highly effective towards gram-negative bacteria than gram-positive bacteria where the zone of inhibition for Escherichia coli was  7 ± 2.7 mm and 5.3 ± 2.1 mm for Staphylococcus aureus.

scholarly journals Synthesis Photocatalytic and Antibacterial Activities of Nickle Doped Tio2 Nanoparticles

2018 ◽  
Vol 34 (6) ◽  
pp. 3140-3144
Author(s):  
Ritu Vershney ◽  
Komal Chelaramani ◽  
Arpan Bhardwaj ◽  
Nayma Siddiqui ◽  
Suresh Kumar Verma
Keyword(s):  
Photocatalytic Degradation ◽  
Tio2 Nanoparticles ◽  
Sol Gel ◽  
Antibacterial Activities ◽  
X Ray Diffraction ◽  
Zone Of Inhibition ◽  
Time Duration ◽  
X Ray ◽  
Gel Technique ◽  
Doped Titania

The synthesis of Ni doped titania (TiO2) nanoparticles were achieved via simple novel sol gel technique, in which Titanium-n-butoxide and NiCl2 were taken as precursors. Effect of different wt% of dopant in TiO2 was studied on photocatalytic degradation of Aniline blue and Toluidine Blue. The study suggested the increased photocatalytic degradation with increased time duration. The synthesized samples were analyzed by surface electron microscopy (SEM) and X-ray diffraction studies. The antibacterial activity was investigated against Gram-positive Staphylococcus aureus bacteriae. Studies revealed that on increasing the dopant concentration, the diameter of zone of inhibition also increased upto 1.5 wt%.

scholarly journals Seasonal Variability in the Composition of Particulate Matter and the Microclimate in Cultural Heritage Areas

Atmosphere ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 595 ◽  
Author(s):  
Radulescu ◽  
Stihi ◽  
Ion ◽  
Dulama ◽  
Stanescu ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Inductively Coupled Plasma ◽  
Chemical Compositions ◽  
Potential Health ◽  
Museum Exhibits ◽  
Inductively Coupled ◽  
Chemical Measurements ◽  
Low Concentrations ◽  
High Concentrations ◽  
Indoor And Outdoor

This study is the first attempt to decipher the effect of particulate matter (PM) composition on people’s health and on historic sites, in correlation with the daily and seasonal microclimate monitoring of the indoor and outdoor areas of the Roman Mosaic Edifice museum (the maritime port of Constanta, Romania). More specifically, the increase of metal concentrations in particulate matter during the summer of 2018 and spring of 2019 in the museum under investigation could possibly be associated with the microclimates of both seasons, with coastal factors, as well as with the anthropic activities specific to the port of Constanta. FTIR and inductively coupled plasma mass spectroscopy (ICP-MS) techniques, used for the investigation of PM2.5–10 samples, revealed high concentrations of Fe, Al-rich, and soluble particles inside the investigated museum area. In this respect, the chemical measurements of the PM2.5–10 masses highlighted high concentrations of heavy metals (i.e., Al, Fe, Zn, Mn, and Pb) and low concentrations of trace metals (i.e., Cr, Ni, Cu, and Cd). Statistical analysis showed that the chemical compositions of the particulate matter in the indoor and outdoor areas of the Roman Mosaic Edifice were influenced by microclimatic conditions, mainly temperature and relative humidity (RH). A potential health risk for tourists is the thermal and humid conditions, alongside the toxic components of the particulate matter. This research seeks to provide solutions for improving the environmental conditions inside the Roman Mosaic Edifice and to offer useful suggestions concerning health promotion and the protection of museum exhibits against possible future deterioration.

Measurement of Low Concentrations of Nanoparticles in Aerosols Using Optical Dielectric Microcavity: The Case of TiO2 Nanoparticles

2018 ◽  
Vol 13 (1-2) ◽  
pp. 38-44 ◽  
Author(s):  
K. N. Min’kov ◽  
A. D. Ivanov ◽  
A. A. Samoilenko ◽  
D. D. Ruzhitskaya ◽  
G. G. Levin ◽  
...  
Keyword(s):  
Tio2 Nanoparticles ◽  
Low Concentrations ◽  
Optical Dielectric

scholarly journals Analysis of Phytochemical Constituents and Biological Activity of Taxus Wallichiana Zucc. Dolakha District of Nepal

2018 ◽  
Vol 6 (2) ◽  
pp. 110-114
Author(s):  
Bimala Subba
Keyword(s):  
Biological Activities ◽  
Radical Scavenging ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Zone Of Inhibition ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Pharmacologically Active ◽  
Taxus Wallichiana

Phytochemical and biological activities of methanolic extract of Taxus wallichiana Zucc. (Leaf, stem) were carried out. The brine shrimp bioassay showed T. wallichiana is pharmacologically active. The antibacterial potential was studied against one gram positive bacteria (Staphylococcus aureus) and one gram negative bacteria (Escherichia Coli) using Agar Well Diffusion Method. Stem of T. wallichiana showed significant zone of inhibition against gram positive bacteria while the leaf of T. wallichiana did not show significant zone of inhibition against both gram positive and gram negative bacteria. Antioxidant activity was evaluated by 2, 2-diphenyl-1-picryl hydrazyl (DPPH) free radical scavenging activity and FRAP assay. Both assay showed that T. wallichiana leaves has high antioxidant activities.Int. J. Appl. Sci. Biotechnol. Vol 6(2): 110-114

scholarly journals FORMULATION AND EVALUATION OF NOVEL ANTIBACTERIAL AND ANTI-INFLAMMATORY CREAM CONTAINING MUNTINGIA CALABURA LEAVES EXTRACT

2017 ◽  
Vol 10 (12) ◽  
pp. 376
Author(s):  
Mahendran Sekar ◽  
Nur Syahira Abdul Jalil
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Infections ◽  
Stable State ◽  
Inflammatory Activity ◽  
Diffusion Method ◽  
Zone Of Inhibition ◽  
Gram Positive Bacteria ◽  
Maximum Inhibition ◽  
Anti Inflammatory ◽  
Muntingia Calabura

  Objective: The main objective of the present study was to formulate antibacterial and anti-inflammatory cream using Muntingia calabura leaves extract.Methods: 500 g of matured leaves of M. calabura were extracted with 70% methanol using maceration method for a week. The antibacterial activity of the extract and formulated cream in different concentration was investigated against two Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) through disc diffusion method. The anti-inflammatory activity of extract and formulated cream was studied using inhibition of albumin denaturation technique.Results: The antibacterial activity of the methanolic extract was studied in different concentrations (5, 10, and 25 mg/ml) and the formulated cream was studied in the concentration of (10, 25, 50, and 100 mg/ml). The extract showed significant antibacterial activity with all the tested pathogens with a zone of inhibition ranges from 3.33 ± 0.88-14.60 ± 0.80 mm. As for the formulated cream, the zone of inhibition for F1 ranged from 0.67 ± 0.67 mm to 14.80 ± 1.17 mm. F2 presented zone of inhibition at 3.40 ± 1.64 mm to 15.00 ± 1.18 mm. The anti-inflammatory activity showed maximum inhibition of 63.93 ± 5.90, 41.83 ± 5.64, and 27.20 ± 2.72 was observed at 1000 μg/ml for the extract, F2 and F1, respectively. The cream was found to be in stable state after 2 months.Conclusion: The results showed that the formulated cream can be used for bacterial infections and to reduce inflammation. We recommend this formulation need to be further developed into commercial standards.

scholarly journals Photocatalytic Coatings - Promising Way to Improve a Quality of Urban Building Surfaces

2015 ◽  
Vol 20 (1-2) ◽  
pp. 113-122 ◽  
Author(s):  
Tereza Sázavská ◽  
Jan Šubrt ◽  
Michaela Jakubičková ◽  
František Peterka
Keyword(s):  
Methylene Blue Degradation ◽  
Gram Positive Bacteria ◽  
Non Invasive ◽  
Building Facades ◽  
Building Surfaces ◽  
Self Cleaning ◽  
One Year ◽  
Texture Characterization

Abstract With the increasing air pollutants particularly in the cities the deteriorating conditions of the buildings accelerate. One of the non-invasive and cheap promising ways how to prevent the buildings against the aged processes caused by biological pollutants or smog exhalation is the innovation of suitable photocatalytic coatings. This work focuses on the characterization of prepared photocatalytic nanocomposite TiO2-SiO2 system to be applied on the building objects in order to improve a quality of their surfaces. The structure and the texture characterization of prepared nanocomposite were determined by electron microscopy (SEM, TEM + EDS). The photocatalytic activity of the composite was determined considering the self-cleaning ability and the antibacterial activity. For self-cleaning characterization the methylene blue degradation was measured. These self-cleaning properties were tested on the various types of supports, which are commonly used in the building facades. To estimate antibacterial and biocidal activity the Gram-negative bacterium Escherichia coli and the gram-positive bacteria Staphylococcus aureus were used. Both methods were done according to standard ISO tests. Next to the laboratory testing the application of the composite under the real condition was implemented. There were treated parts of the concrete outside wall with the composite and after more than one year the colour changed analysis of the wall surface was characterized.

Nitrogen as a potential health hazard

1982 ◽  
Vol 296 (1082) ◽  
pp. 543-550 ◽  
Keyword(s):  
Tobacco Smoke ◽  
Human Cancer ◽  
Health Hazard ◽  
The Body ◽  
Nitroso Compounds ◽  
Potential Health ◽  
Low Concentrations ◽  
Potential Health Hazard ◽  
Low Toxicity ◽  
Nitrate And Nitrite

Possible ways in which disturbances of the nitrogen cycle might result in deleterious effects on human and animal life are discussed, including the hazardous properties of oxides ofN, nitrate and nitrite, and certain N-nitroso compounds that may be found in the environment. The main biological actions of oxides of N are caused by NO 2 , which is a powerful respiratory irritant. Nitrates have relatively low toxicity but nitrites can cause methaemoglobinaemia, which may be fatal, particularly in infants. Nitrosamines occur in the environment in very low concentrations in certain foods, in tobacco smoke, and in the atmosphere in some areas. Carcinogenic nitrosamines can also be formed in the body by reaction of endogenous amines with nitrites, part of the latter being derived from saliva. Although nitrosamines are established as powerful carcinogens in animals, their possible role in human cancer is uncertain and requires further study.

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