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Seaweeds as Sustainable Sources for Food Packaging
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Y. S. M. Senarathna, I. Wickramasinghe, S. B. Navaratne
Agar is another type of sulfated polysaccharide (Figure 7.7) derived from red algae that consists of α (1–4)-3, 6-anhydro-L-galactose and β 9(1–3)-D-galactose residues (Carina et al. 2021). Two main parts can be identified in agar structure: agaropectin, which is the non-gelling fraction, and agarose, the gelling fraction. In producing agar, the agaropectin part is removed and only the agarose part is used to get higher gel strength (Mostafavi and Zaeim 2020). Hence, the applicability of agar is improved in food and medical industries as a thickening, emulsifying, gelling and texture modification agent (Carina et al. 2021). The gel formation capacity of agar leads to make consistent coatings and film matrices (Mostafavi and Zaeim 2020), thus widening its applicability in making packaging materials.
Principles and Methods of Ocular Pharmacokinetic Evaluation
Published in David W. Hobson, Dermal and Ocular Toxicology, 2020
Drug can be either in solution or in an agar gel. In either case the solution must be distilled water, or at least contain no anions or cations since they, being more mobile, will carry the current in preference to the drug and enhanced drug levels will not ensue. Similarly, the compound to be iontophoresed must be charged. Solutions can be placed in a cup shaped to fit the eye at one end as shown in Figure 10. For an agar solution of nonthermolabile drugs, the procedure is that distilled water is heated to boiling and, with the heat turned off, agar, to give a final concentration of 4% w/v, is added to the drug solution. As the solution cools, the agar can be either injected or poured into appropriate tubings. The agar/drug solution is then placed in contact with the appropriate electrode, and a small amount of agar is extruded from the end of the tubing (Figure 11). The latter procedure ensures that good contact is made between the ocular tissue and the drug-containing agar. This procedure is used for iontophoresis of fluorescein for aqueous humor turnover studies in man93–96 and for the enhancement of drug penetration in experimental animals.97,98 Only small currents (about 200 μA) for short time periods (a few seconds to a minute) can result in greatly enhanced tissue penetration. Kinetics depend on the final drug concentration reached in the various compartments and their subsequent clearance rates.
Assay of Antibiotics in Mammalian Cell Culture
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
The melted agar and the remaining ingredients are combined before a significant loss in temperature occurs. The nutrient and cell mixture is slowly poured into the flask containing the melted agar. Care should be taken to avoid frothing and bubble formation in the agar. Stir until the cells are uniformly dispersed, and immediately pour the agar mixture into sterile plates using the entire formulation of 220 ml for a single 23×23 plate. Use 25 ml for 100 mm petri plates. Distribute the agar evenly over the plate and allow to cool on a level surface.
Urethral instillation of chlorhexidine gel is an effective method of sterilisation
Published in Arab Journal of Urology, 2021
Osama Shaeer, Amr Abdel- Raheem, Haitham Elfeky, Ahmad Seif, Tarek M. Abdel-Raheem, Amgad Elsegeiny, May Sherif Soliman, Emad B. Basalious, Kamal Shaeer
Swab samples were directly transported to the laboratory for immediate culture. Culture on blood agar base supplemented with blood, MacConkey agar, and chocolate agar was done followed by incubation at 37°C for 48 h. Plates were examined after 24 and 48 h, and microbial growth was identified using standard procedures. Lactose fermenter colonies were subjected to conventional biochemical reaction in the form of triple sugar iron, motility indole ornithine, lysine iron agar, urease, and citrate. Non-lactose fermenter colonies were subjected to oxidase; if negative, a Gram stain was done to exclude Acinetobacter (coccobacilli) and if Gram-negative bacilli were found, the previous biochemical reactions were performed. Staphylococcus colonies were identified further using the mannitol salt and the DNase agar. Quality control was done for performance of the different media and identification methods in accordance with applicable regulations and accreditation requirements with Clinical and Laboratory Standards Institute (CLSI) guidance, using American Type Culture Collection (ATCC) strains as control strains for susceptibility testing at appropriate intervals [11].
Green synthesis and biomedicinal applications of silver and gold nanoparticles functionalized with methanolic extract of Mentha longifolia
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2021
Abdur Rauf, Touqeer Ahmad, Ajmal Khan, Ghias Uddin, Bashir Ahmad, Yahia Nasser Mabkhot, Sami Bawazeer, Nadia Riaz, Bates Kudaibergenova Malikovna, Zainab M. Almarhoon, Ahmed Al-Harrasi
The MLE and synthesised NPs were checked for their antibacterial activities against various bacterial strains, that is, Klebsiella pneumoniae (ATCC: 13882) (K. pneumoniae), Staphylococcus aureus (ATCC: 25923) (S. aureus), Bacillus subtilis (ATCC: 21332) (B. subtilis), using the standard protocol [46]. K. pneumoniae, a Gram-negative, while S. aureus and B. subtilis as Gram-positive bacteria were subjected to trials. These organisms were stored in Muller-Hinton agar (MHA) in the refrigerator at 4 °C. Modified agar well diffusion procedure was followed to study antibacterial activity of MLE and synthesised NPs. (MHA) agar was used as a growth medium. The cultures were cultivated and then incubated at 37 °C for 24 to 72 h, and taken as triplicate. Sterilized Petri-dishes were used for broth culture, 0.6 ml of the broth culture was added and Petri-dishes were sterilized first and then 20 ml sterilized molten MHA was added to each petri-dish. Wells were bored in the medium and 0.2 ml volume of crude extract was added to each well with the help of a micro pipette, while 2 mg/mL of synthesized NPs were used to examine their antibacterial ability. Streptomycin (2 mg/mL) was used as a standard drug. Petri-dishes were kept in a laminar flow hood for 1 h for proper diffusion, later plates were incubated at 37 °C for 24 h. Next day the zone of inhibition was measured [47].
Bacterial contamination of forehead skin and surgical mask in aerosol-producing dental treatment
Published in Journal of Oral Microbiology, 2021
Madline P Gund, Gabor Boros, Matthias Hannig, Sigrid Thieme-Ruffing, Barbara Gärtner, Tilman R Rohrer, Arne Simon, Stefan Rupf
The microbiological methodology used in this study had the advantage that the cultivation on agar only detects viable bacteria. The use of nucleic acid-based methods would probably have led to a larger number of detected species. This would have demonstrated the potential of aerosols to transport bacteria, regardless of their viability. From the infectious disease perspective, however, only viable bacteria pose a potential risk to the dental staff. The agar used usually serves to detect the majority of fast-growing bacteria. Slow-growing species may have been underestimated. However, it was to be expected that readily cultivable and robust bacteria, in particular, would play a role since the resident microbiota would offer a certain degree of protection against invading bacteria. Additionally, bacteria that spread easily would also be at an advantage if further contamination were to occur from the forehead or mask onto surfaces, other regions of the body, or other individuals. The MALDI-TOF MS analysis we used was restricted to colonies that were identified as different phenotypes. This may potentially have resulted in underestimation of the bacterial spectrum on both foreheads and surgical masks. In our study, surgical masks were worn for 60 min. Published data suggest, as shown by our own preliminary tests, that in the absence of aerosol-releasing treatments, surgical masks were completely free of detectable bacteria. Hence, this potential limitation is irrelevant to the conclusions of our study.