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Comparative singlet oxygen photosensitizer efficiency of berberine, rose bengal, and methylene blue by time course nuclear magnetic resonance (NMR) monitoring of a photochemical 4+2 cycloaddition endoperoxide formation

Su et al. | May 14, 2021

Comparative singlet oxygen photosensitizer efficiency of berberine, rose bengal, and methylene blue by time course nuclear magnetic resonance (NMR) monitoring of a photochemical 4+2 cycloaddition endoperoxide formation

Berberine, a natural product alkaloid, has been shown to exert biological activity via in situ production of singlet oxygen when photo irradiated. Berberine utilizes singlet oxygen in its putative mechanism of action, wherein it forms an activated complex with DNA and photosensitizes triplet oxygen to singlet oxygen to specifically oxidize guanine residues, thereby halting cell replication and leading to cell death. This has potential application in photodynamic therapy, alongside other such compounds which also act as photosensitizers and produce singlet oxygen in situ. The quantification of singlet oxygen in various photosensitizers, including berberine, is essential for determining their photosensitizer efficiencies. We postulated that the singlet oxygen produced by photoirradiation of berberine would be superior in terms of singlet oxygen production to the aforementioned photosensitizers when irradiated with UV light, but inferior under visible light conditions, due to its strong absorbance of UV wavelengths.

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Testing Different Polymers and Boron Nitride Nanotube Properties in Fabrication of Ion-selective Membranes

Yi et al. | Sep 28, 2020

Testing Different Polymers and Boron Nitride Nanotube Properties in Fabrication of Ion-selective Membranes

One largely untapped source of clean energy is the use of osmotic gradients where freshwater and saltwater are mixed, for example at estuaries. To harness such energy, charge-selective membranes are needed to separate the anions and cations in saltwater, establishing an electric potential like a battery. The objective of this study was twofold: to investigate the creation of the polymer matrix and test the properties of boron nitride nanotubes, as both are essential in the creation of an ion-selective membrane. Out of three polymer samples tested in this study, the mixture known as Soltech 704 showed the best resistance to etching, as well as the highest UV cure rate.

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Efficient synthesis of superabsorbent beads using photopolymerization with a low-cost method

Wang et al. | Jun 09, 2023

Efficient synthesis of superabsorbent beads using photopolymerization with a low-cost method

Superabsorbent beads are remarkable, used throughout our daily lives for various practical applications. These beads, as suggested by their name, possess a unique ability to absorb and retain large quantities of liquids. This characteristic of absorbency makes them essential throughout the medical field, agriculture, and other critical industries as well as in everyday products. To create these beads, the process of photopolymerization is fast growing in favor with distinct advantages of cost efficiency, speed, energy efficiency, and mindfulness towards the environment. In this article, researchers explore the pairing of cheap monomers with accessible equipment for creation of superabsorbent beads via the photopolymerization process. This research substantially demonstrates the successful application of photopolymerization in producing highly absorbent beads in a low-cost context, thereby expanding the accessibility of this process for creating superabsorbent beads in both research and practical applications.

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Analysis of ultraviolet light as a bactericide of gram-negative bacteria in Cladophora macroalgae extracts

Newell et al. | Nov 07, 2022

Analysis of ultraviolet light as a bactericide of gram-negative bacteria in <em>Cladophora</em> macroalgae extracts

Here, the authors sought to use Cladophora macroalgae as a possible antibiotic to address the growing threat of antibiotic resistance in pathogenic bacteria. However, when they observed algae extracts to be greatly contaminated with gram-negative bacteria, they adapted to explore the ability to use ultraviolet light as a bactericide. They found that treatment with ultraviolet light had a significant effect.

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The Inhibitory Effect of Probiotics on the Growth and Biofilm Formation of Salmonella Sp.

Lee et al. | Jan 26, 2019

The Inhibitory Effect of Probiotics on the Growth and Biofilm Formation of Salmonella Sp.

Salmonella is a genus of bacteria responsible for over 90 million cases of intestinal illnesses yearly. Like many bacteria, Salmonella can create a biofilm matrix, which confers stronger resistance against antibiotics. However, there has been relatively little research on the inhibition of Salmonella biofilm formation, which is a crucial factor in its widespread growth. In this study, Lee and Kim quantitatively measure the effectiveness of several common probiotics in inhibiting Salmonella bacterial growth. They found concentration-dependent antibacterial effects varied among the probiotics tested, indicating the possibility of probiotic species-specific mechanisms of Salmonella growth inhibition.

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QuitPuff: A Simple Method Using Saliva to Assess the Risk of Oral Pre-Cancerous Lesions and Oral Squamous Cell Carcinoma in Chronic Smokers

Shamsher et al. | Mar 27, 2019

QuitPuff: A Simple Method Using Saliva to Assess the Risk of Oral Pre-Cancerous Lesions and Oral Squamous Cell Carcinoma in Chronic Smokers

Smoking generates free radicals and reactive oxygen species which induce cell damage and lipid peroxidation. This is linked to the development of oral cancer in chronic smokers. The authors of this study developed Quitpuff, simple colorimetric test to measure the extent of lipid peroxidation in saliva samples. This test detected salivary lipid peroxidation with 96% accuracy in test subjects and could serve as an inexpensive, non-invasive test for smokers to measure degree of salivary lipid peroxidation and potential risk of oral cancer.

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Mechanistic deconvolution of autoreduction in tetrazolium-based cell viability assays

Tran et al. | Jul 12, 2024

Mechanistic deconvolution of autoreduction in tetrazolium-based cell viability assays

Optical reporters like tetrazolium dyes, exemplified by 5-diphenyl tetrazolium bromide (MTT), are effective tools for quantifying cellular responses under experimental conditions. These dyes assess cell viability by producing brightly-colored formazan dyes when reduced inside active cells. However, certain small molecules, including reducing agents like ascorbic acid, cysteine, and glutathione (GSH), can interfere with MTT assays, potentially compromising accuracy.

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