There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

This review gives an updated picture of each class of phenolic compounds and their properties. The most common classification implies the subdivision of phenolics in two main groups: flavonoids (e.g., anthocyanins, flavanols, flavanones, flavonols, flavonones, and isoflavones) and non-flavonoids (e.g., phenolic acids, xanthones, stilbens, lignans, and tannins) polyphenols. The great interest in polyphenols is associated with their high potential application for food preservation and for therapeutic beneficial use. The relationship between polyphenol intake and human health has been exploited with special reference to cardiovascular diseases, hypertension, diabetes, metabolic syndrome, obesity, and cancer. The use of current existing databases of bioactive compounds including polyphenols is described as key tools for human health research.

/pdf/polyphenols-a-concise-overview-on-the-chemistry-occurrence-2evnm5d0qr.pdf

Polyphenols: A concise overview on the chemistry, occurrence, and human health

Catechin, the name of which is derived from catechu of the extract of Acacia catechu L [...].

https://www.mdpi.com/1420-3049/24/3/528/pdf

Catechin in Human Health and Disease

Dissolution of cellulose in ionic liquids and their mixed cosolvents: A review

9.19 wt % of microcrystalline cellulose (MCC) could be dissolved in a new mixed solvent of tetra(n-butyl)ammonium hydroxide (TBAH; 20 wt %) and dimethyl sulfoxide (DMSO; 80 wt %) within 5 min at room temperature. The ratio of TBAH in the mixed solvent (WTBAH) is found to exert great influence on the solubility of cellulose. Dissolution mechanism relative to radical reactions has been proposed according to electron spin resonance (ESR) and UV–vis results, showing positive correlation between cellulose solubility and the radical amount produced in the mixed solvent (i.e., WTBAH). Partial degradation of the reducing AGU terminals via radical attack could be observed, followed by recombination of cellulose chain radicals, resulting in amorphous structures of all regenerated cellulose with higher average degree of polymerization values. Therefore, dissolution mechanism with regard to radical reactions has been proposed in this letter, supplementing the predominant electron donor–acceptor complexation theory.

Cellulose Dissolution in a Mixed Solvent of Tetra(n-butyl)ammonium Hydroxide/Dimethyl Sulfoxide via Radical Reactions

The proanthocyanidins from ethanol extracts (80%, v/v) of Acacia mearnsii (A. mearnsii) bark on chemical-based and cellular antioxidant activity assays as well as carbolytic enzyme inhibitory activities were studied. About 77% of oligomeric proanthocyanidins in ethanol extracts of A. mearnsii bark were found by using normal-phase HPLC. In addition, HPLC-ESI-TOF/MS and MALDI-TOF/TOF MS analyses indicated that proanthocyanidins from A. mearnsii bark exhibited with a degree of polymerization ranging from 1 to 11. These results of combined antioxidant activity assays, as well as carbolytic enzyme inhibitory activities of proanthocyanidins from A. mearnsii bark, indicated an encouraging antioxidant capacity for the high polyphenol content and a potential for use as alternative drugs for lowering the glycemic response.

Analytical Profiling of Proanthocyanidins from Acacia mearnsii Bark and In Vitro Assessment of Antioxidant and Antidiabetic Potential

The stability and bioaccessibility of polyphenol from Acacia mearnsii bark were measured at various stages during in vitro simulated digestion. Subsequently, the changes in the total polyphenol content (TPC) and biological activity were studied. The results showed that the phenolic compounds from A. mearnsii remained stable, and TPC underwent few changes during gastric digestion. Nonetheless, intestinal digestion led to the degradation of proanthocyanidins (PAs) and a significant decrease in TPC (26%). Degradation was determined by normal-phase HPLC and gel permeation chromatography. Only monomers, dimers, and trimers of flavan-3-ols were identified in the serum-accessible fraction for characterization of their bioaccessibility. The results also indicated the obvious antioxidant capacity of PAs from A. mearnsii bark, and ~53% of the α-glucosidase⁻inhibitory effect was preserved. All these findings show that PAs from A. mearnsii bark as a native plant source may be particularly beneficial for human health as a natural nutritional supplement.

https://www.mdpi.com/1420-3049/23/7/1804/pdf

Effects of In Vitro Digestion on the Content and Biological Activity of Polyphenols from Acacia mearnsii Bark.

Proanthocyanidins in ethanol extracts from the barks of Acacia mangium and Larix gmelinii were analyzed by gel permeation chromatography, MALDI-TOF/TOF MS, and HPLC/MS. The inhibitory effects of proanthocyanidins and acid-catalyzed hydrolysis of proanthocyanidins against carbolytic enzymes were also tested. A significant relationship between carbolytic enzymes inhibition and degree of polymerization was established, showing that the degree of polymerization is a major contributor to the biological activity of the proanthocyanidins from both types of woody plant bark. The results indicate that proanthocyanidins from the barks of A. mangium and L. gmelinii have potential antidiabetic properties.

/pdf/characterization-and-potential-antidiabetic-activity-of-4t7hh4ruz0.pdf

Xiao Chen

Papers

Cellulose Dissolution in a Mixed Solvent of Tetra(n-butyl)ammonium Hydroxide/Dimethyl Sulfoxide via Radical Reactions

Analytical Profiling of Proanthocyanidins from Acacia mearnsii Bark and In Vitro Assessment of Antioxidant and Antidiabetic Potential

Effects of In Vitro Digestion on the Content and Biological Activity of Polyphenols from Acacia mearnsii Bark.

Characterization and potential antidiabetic activity of proanthocyanidins from the barks of Acacia mangium and Larix gmelinii.

A luminescent cellulose ether with a regenerated crystal form obtained in tetra(n-butyl)ammonium hydroxide/dimethyl sulfoxide