[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

The ability of probiotic bacteria to adhere to the intestinal epithelium play an important role in colonization of the gastrointestinal tract, preventing their elimination by peristalsis and providing a competitive advantage in this ecosystem. To identify bacterial traits related to adhesion the probiotic strain L. acidophilus M92 was examined for autoaggregation ability and cell surface hydrophobicity L. acidophilus M92 exhibits a strong autoaggregation phenotype and also coaggregation with some pathogen microorganisms that may form a barrier that prevents their colonization. The examined probiotic strain manifests a good degree of hydrophobicity determined by microbial adhesion to hydrocarbons. Aggregation and hydrophobicity were abolished upon exposure of the cells to pronase, which suggests the possible role of cell surface layer (S-layer) proteins, approximated at 45 kDa, in a L. acidophilus M92. The relationship between autoaggregation and adhesion ability to intestinal tissue was investigated by observing the adhesivity of L. acidophilus M92 to porcine ileal epithelial cells. Removal of the S-layer proteins by extraction with 5 M LiCl reduced autaggregation and in vitro adhesion of this strain.

Adhesion and aggregation ability of probiotic strain Lactobacillus acidophilus M92

There is great need for stand-alone luminescence-based chemosensors that exemplify selectivity, sensitivity, and applicability and that overcome the challenges that arise from complex, real-world media. Discussed herein are recent developments toward these goals in the field of supramolecular luminescent chemosensors, including macrocycles, polymers, and nanomaterials. Specific focus is placed on the development of new macrocycle hosts since 2010, coupled with considerations of the underlying principles of supramolecular chemistry as well as analytes of interest and common luminophores. State-of-the-art developments in the fields of polymer and nanomaterial sensors are also examined, and some remaining unsolved challenges in the area of chemosensors are discussed.

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Supramolecular Luminescent Sensors

The high versatility of poly(vinylpyrrolidone) (PVP) can be explained by its diverse properties including its solubility in water and in a broad range of liquid media, high chemical and thermal resistance, and unique wetting, binding, and film-forming properties. Thanks to biocompatibility, absence of toxicity and high capacity to form interpolymer complexes, PVP is widely used for designing materials for different applications, such as biomaterials for medical and nonmedical uses. This review summarizes a vast diversity of applicative examples showing the tremendous opportunities for future research and developments of PVP based biomaterials.

Poly(vinylpyrrolidone) – A Versatile Polymer for Biomedical and Beyond Medical Applications

Green synthesis of silver nanoparticles makes use of plant constituents, like carbohydrates, fats, enzymes, flavonoids, terpenoids, polyphenols, and alkaloids, as reducing agents to synthesize silver nanoparticles. The present study for the first time utilized seed extract of Tectona grandis (teak) for reduction of 1 mM silver nitrate solution to silver nanoparticles. The method proved to be very simple, cost-efficient, and convenient. Synthesis of nanoparticles was confirmed by visual detection in which the colorless solution gets changed to a brown-colored solution. Further characterization was done by UV-visible spectroscopy, XRD, FTIR analysis, SEM/EDS, FESEM, and TEM. Size of silver nanoparticles was found to be 10–30 nm approximately as determined by transmission electron microscopy (TEM). Energy-dispersive spectra (EDS) revealed that nanoparticles contain silver in its pure form. Well diffusion method showed the antimicrobial effect of AgNPs on different microorganisms with the zone of inhibition of 16 mm for Staphylococcus aureus, 12 mm for Bacillus cereus, and 17 mm for E. coli when 50 μg of AgNPs was used. Minimum inhibitory concentration was found to be 5.2, 2.6, and 2.0 μg/ml for Bacillus cereus, Staphylococcus aureus, and E. coli respectively. Mode of action of antimicrobial activity of nanoparticles was investigated by determining leakage of reducing sugars and proteins, suggesting that AgNPs were able to destroy membrane permeability.

/pdf/green-synthesis-of-silver-nanoparticles-from-tectona-grandis-2o8mwgp26f.pdf

Green synthesis of silver nanoparticles from Tectona grandis seeds extract: characterization and mechanism of antimicrobial action on different microorganisms

Effects of cinnamaldehyde on Escherichia coli and Staphylococcus aureus membrane

Immunomodulatory activities of polysaccharides from Ganoderma on immune effector cells.

http://users.encs.concordia.ca/~mojtaba/elec6271/melamine-detection%20AuNPs.pdf

Visual detection of melamine in raw milk by label-free silver nanoparticles

With the rapid development of modern society, many chronic diseases are increasing including diabetes, obesity, cardiovascular diseases, etc., which further cause an increased death rate worldwide. A high caloric diet with reduced natural polysaccharides, typically indigestible polysaccharides, is considered a health risk factor. With solid evidence accumulating that indigestible polysaccharides can effectively prevent and/or ameliorate symptoms of many chronic diseases, we give a narrative review of many natural polysaccharides extracted from various food resources which mainly contribute their health beneficial functions via intestinal fermentation.

Beneficial Effect of Intestinal Fermentation of Natural Polysaccharides

As plant-derived natural products, saponins have been widely applied for the dietary modification of metabolic syndrome. However, the underlying mechanisms of their preventive and therapeutic effects are still largely unclear. Nuclear receptors have been identified as potential pharmaceutical targets for treating various types of metabolic disorders. With similar structure to endogenous hormones, several saponins may serve as selective ligands for nuclear receptors. Recently, a series of saponins are proved to exert their physiological activities through binding to nuclear receptors. This review summarizes the biological and pharmacological activities of typical saponins mediated by some of the most well described nuclear receptors, including the classical steroid hormone receptors (ER, GR, MR, and AR) and the adopted orphan receptors (PPAR, LXR, FXR, and PXR).

Tiehua Zhang

Papers

Effects of cinnamaldehyde on Escherichia coli and Staphylococcus aureus membrane

Immunomodulatory activities of polysaccharides from Ganoderma on immune effector cells.

Visual detection of melamine in raw milk by label-free silver nanoparticles

Beneficial Effect of Intestinal Fermentation of Natural Polysaccharides

Saponins as modulators of nuclear receptors.