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On the Relationship Between Viscosity and Surface Tension

Wei et al. | Sep 16, 2014

On the Relationship Between Viscosity and Surface Tension

Surface tension and viscosity are both measures of how "sticky" a liquid is, but are they related? The authors here investigate the surface tension and viscosity of mixtures of water with different concentrations of agar agar, flour, or detergent. Surprisingly, they find that the least viscous mixtures had the strongest surface tensions, indicating that the two properties are not linked.

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Modeling the effects of acid rain on bacterial growth

Shah et al. | Nov 17, 2020

Modeling the effects of acid rain on bacterial growth

Acid rain has caused devastating decreases in ecosystems across the globe. To mimic the effect of acid rain on the environment, the authors analyzed the growth of gram-negative (Escherichia coli) and gram-positive (Staphylococcus epidermidis) bacteria in agar solutions with different pH levels. Results show that in a given acidic environment there was a significant decrease in bacterial growth with an increase in vinegar concentration in the agar, suggesting that bacterial growth is impacted by the pH of the environment. Therefore, increased levels of acid rain could potentially harm the ecosystem by altering bacterial growth.

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Effects of spices on rice spoilage

Govindaraj et al. | Aug 15, 2022

Effects of spices on rice spoilage

In this work, based on centuries of history where spices have been used and thought to have antimicrobial properties that prolong the shelf life of food, the authors investigated if several spices used in Indian cooking could delay the spoilage of cooked white rice. Based on changed in appearance and smell, as well as growth on agar plates, they found that cinnamon was the most effective in delaying spoilage, followed by cumin, pepper, garlic, and ginger. Their findings suggest the ability to use spices rather than chemical food preservatives to prolong the shelf life of foods.

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Effects of Temperature on Hand Sanitizer Efficiency

Molom-Ochir et al. | May 11, 2022

Effects of Temperature on Hand Sanitizer Efficiency

Here, recognizing the widespread use of hand sanitizers, the authors investigated their effectiveness in relation to storage temperature. They applied hand sanitizer before and after touching a cell phone and used LB-agar plates to monitor the growth of bacteria following this process. They found that 70% ethyl-alcohol-based sanitizers are least effective at temperatures above 107.27 °F and most effective at 96.17 °F.

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Antibacterial effectiveness of turmeric against gram-positive Staphylococcus epidermidis

Cox et al. | Jan 10, 2022

Antibacterial effectiveness of turmeric against gram-positive <i>Staphylococcus epidermidis</i>

Infections caused by antibiotic resistance are a leading issue faced by the medical field. The authors studied the antibacterial effectiveness of turmeric against gram-positive Staphylococcus epidermidis using antibiotic sensitivity disks. They infused blank antibiotic sensitivity disks with a 5% concentrated solution of turmeric and placed them on agar plates inoculated with bacteria. Overall, there was no measurable ZOI surrounding the turmeric disk so the measurements for all trials were 0 cm, suggesting that turmeric at a 5% concentration is not an effective antibacterial against S. epidermidis.

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The Emergence of Tetracycline Resistance in Rumen Bacteria

Memili et al. | Sep 16, 2016

The Emergence of Tetracycline Resistance in Rumen Bacteria

The emergence of antibiotic-resistant pathogenic bacteria is a major concern for human health, rendering some antibiotics ineffective in treating diseases. The authors of this study tested the hypothesis that exposing rumen bacteria to tetracycline will gradually lead to the development of tetracycline-resistant bacteria, some of which will develop multidrug resistance.

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Strain-specific and photochemically-activated antimicrobial activity of berberine and two analogs

Sun et al. | Nov 17, 2020

Strain-specific and photochemically-activated antimicrobial activity of berberine and two analogs

In this study, the authors investigate the antimicrobial effects of berberine and berberine analogs. Berberine is extracted from plants and is a naturally occurring alkaloid, and is also excited photochemically. Using three different assays, the authors tested whether these compounds would inhibit bacterial growth. They found that these compounds were antibacterial and even more so when used with photoirradiation. This study has important antibacterial implications.

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Green Tea Extract as an Environmentally Friendly Antibacterial Agent Against Pseudomonas syringae pv. tomato on Plants

Lo et al. | Oct 27, 2015

Green Tea Extract as an Environmentally Friendly Antibacterial Agent Against <i>Pseudomonas syringae pv. tomato </i>on Plants

Plant pathogens can cause significant crop loss each year, but controlling them with bactericides or antibiotics can be costly and may be harmful to the environment. Green tea naturally contains polyphenols, which have been shown to have some antimicrobial properties. In this study, the authors show that green tea extract can inhibit growth of the plant pathogen Pseudomonas syringae pv. tomato and may be useful as an alternative bactericide for crops.

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Characterization of antibacterial properties of common spices

Gehad et al. | Oct 03, 2020

Characterization of antibacterial properties of common spices

Bacterial infection is resurging as one of the most dangerous challenges facing the medical establishment. Americans spend about 55 to 70 billion dollars per year on antibiotics, yet these antibiotics are becoming increasingly ineffective as illness-causing bacteria gain resistance to the prescribed drugs. We tested if 11 commonly-used spices could inhibit growth of the gram-negative bacteria, E. coli, the main takeaway from these experiments is that certain spices and herbs have antibacterial effects that inhibit growth of E.coli , and these spices could show similarly promising activity towards other bacteria.

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