Quantum-Acoustical Drude Peak Shift.

Quantum acoustics-a recently developed framework parallel to quantum optics-establishes a nonperturbative and coherent treatment of the electron-phonon interaction in real space. The quantum-acoustical representation reveals a displaced Drude peak hiding in plain sight within the venerable Fröhlich model: the optical conductivity exhibits a finite frequency maximum in the far-infrared range and the dc conductivity is suppressed. Our results elucidate the origin of the high-temperature absorption peaks in strange or bad metals, revealing that dynamical lattice disorder steers the system towards a non-Drude behavior.

Near-infrared fluorescent indolizine-dicyanomethylene-4H-pyran hybrids for viscosity imaging in living cells.

The development of near-infrared organic fluorescent dyes with tunable emission profiles is highly required in the field of biological sensing and imaging. In this paper, we designed and synthesized two organic fluorescent dyes, DCM-1 and DCM-2, through the hybridization of indolizine and dicyanomethylene-4H-pyran skeleton. These two compounds show near-infrared fluorescence with emission maximum approximately at 640 and 680 nm, respectively. Notably, both DCM-1 and DCM-2 have specific responses to viscosity without being interfered by biological relevant species. Cell experiments demonstrate that DCM-1 and DCM-2 can detect dynamic changes in viscosity within living cells, suggesting their potential applications in chemical biology research.

Complex phase diagram and supercritical matter.

The supercritical region is often described as uniform with no definite transitions. The distinct behaviors of the matter therein, e.g., as liquidlike and gaslike, however, suggest "supercritical boundaries." Here we provide a mathematical description of these phenomena by revisiting the Yang-Lee theory and introducing a complex phase diagram, specifically a four-dimensional (4D) one with complex T and p. While the traditional 2D phase diagram with real temperature T and pressure p values (the physical plane) lacks Lee-Yang (LY) zeros beyond the critical point, preventing the occurrence of criticality, the off-plane zeros in this 4D scenario still induce critical anomalies in various physical properties. This relationship is evidenced by the correlation between the Widom line and LY edges in van der Waals, 2D Ising model, and water. The diverged supercritical boundaries manifest the high-dimensional feature of the phase diagram: e.g., when LY zeros of complex T or p are projected onto the physical plane, boundaries defined by isobaric heat capacity C_{p} or isothermal compression coefficient K_{T} emanates. These results demonstrate the incipient phase transition nature of the supercritical matter.

Effect of Lactobacillus acidophilus, Oenococcus oeni, and Lactobacillus brevis on Composition of Bog Bilberry Juice.

This study investigated the impact of Lactobacillus acidophilus NCFM, Oenococcus oeni Viniflora® Oenos and Lactobacillus brevis CICC 6239 on bog bilberry juice with a considerably low pH and rich in anthocyanins content. Moreover, the effects of the strains on the composition of phenolic compounds, amino acids, ammonium ion, biogenic amines, reduced sugars, organic acids, and color parameters of the juice were studied. All three bacteria consumed sugars and amino acids but exhibited different growth patterns. Lactic acid was detected only in L. acidophilus inoculated juice. The content of the phenolic compounds, especially anthocyanins, decreased in juice after inoculation. The CIELa*b* analysis indicated that the juice inoculated with L. acidophilus and O. oeni showed a decrease on a* and b* (less red and yellow) but an increase on L (more lightness), whereas the color attributes of L. brevis inoculated juice did not significantly change. Based on this study, L. brevis showed the most optimal performance in the juice due to its better adaptability and fewer effects on the appearance of juice. This study provided a useful reference on the metabolism of lactic acid bacteria in low pH juice and the evolution of primary and secondary nutrients in juice after inoculated with lactic acid bacteria.

Comparison of physicochemical indexes, amino acids, phenolic compounds and volatile compounds in bog bilberry juice fermented by Lactobacillus plantarum under different pH conditions.

This study aimed to investigate the effect of Lactobacillus plantarum strains on quality improvement of bog bilberry juice. Bog bilberry juice with different pH conditions was fermented by Lactobacillus B7 or C8-1 strain. Physicochemical index, amino acids, phenolic compounds, and volatiles of these fermented juices were compared. Results indicated that Lactobacillus plantarum strains preferred to metabolize malic acid and reducing sugar in non-pH-adjusted juice (NJ, pH 2.65), whereas quinic and citric acids were largely consumed in pH-adjusted juice (AJ, pH 3.50). Shikimic acid and aromatic amino acids were significantly accumulated in pH-adjusted juice, and phenolic compounds in both juices were significantly reduced. These strains enhanced the composition and concentration of volatiles compounds in non-pH-adjusted juice and improved the floral and fruity flavors. However, concentration and complexity of volatiles were reduced in pH-adjusted juices.

Effect of Oak Chips on Evolution of Phenolic Compounds and Color Attributes of Bog Bilberry Syrup Wine During Bottle-Aging.

This study investigated the evolution of phenolic compounds of bog bilberry syrup wine during a bottle-aging process, and further estimated the oak chip treatment on the wine color alteration. The wine was macerated with oak chips (2 or 5 g/L under light or medium toasting level) for 20 d and then bottle-aged for 6 mo. Results showed that the oak chip treatment significantly increased the content of phenolic compounds and enhanced the copigmented anthocyanin level before aging. It also resulted in an increase on a* and C* but a decrease on L* , b* , and H* of the wine. During aging process, a content decrease of total phenol and antioxidant capacity of the wine was observed. Phenolic acids, flavonol glycosides, and anthocyanins reduced the content, whereas flavonol increased the content. Free and copigmented anthocyanin levels decreased, whereas polymerized anthocyanins level increased. This process caused an increase on L* , b* , and H* , but a decrease on a* and C* . The oak chip treatment delayed the wine color change and its effect was mainly depended on the addition amount. Partial least square regression revealed that flavonol glycosides, phenolic acids, and anthocyanins displayed a positive correlation with L* , b* , and H* , but a negative correlation with a* and C* . Quercetin-3-O-glucuronide, myricetin-3-O-galactoside, chlorogenic acid, and quercetin exerted a more important effect on the color alteration in wine.

Effect of Raw Material, Pressing and Glycosidase on the Volatile Compound Composition of Wine Made From Goji Berries.

This study investigated the effect of raw material, pressing, and glycosidase on the aromatic profile of goji berry wine. The free-run and the pressed juice of dried and fresh goji berries were used for wine production, whereas glycosidase was applied to wine after fermentation. Dried goji berry fermented wine exhibited much stronger fruity, floral, caramel, and herbaceous odors due to higher levels of esters, ß-ionone and methionol. However, fresh berry fermented wine possessed stronger chemical notes due to higher levels of 4-ethylphenol. Pressing treatment reduced the fruity and caramel odors in these fermented wines, and fresh berry free-run juice fermented wine exhibited the least floral aroma. Glycosidase addition did not alter the aromatic composition of wines. The principal component analysis indicated that goji raw material played a primary role in differentiating the aromatic profiles of the wines due to the difference on the content of 20 esters, nine benzenes, eight aldehydes/ketones, three acids, two alcohols and six other volatiles. The content differences on isopentyl alcohol, styrene, benzyl alcohol, 1-octanol, (E)-5-decen-1-ol, 1-hexanol, and ß-cyclocitral resulted in the segregation of the wines with and without the pressing treatment, especially for fresh berry fermented wine.