Portraying on-road CO2 concentrations using street view panoramas and ensemble learning.

A significant reduction in carbon dioxide (CO2) emissions caused by transportation is essential for attaining sustainable urban development. Carbon concentrations from road traffic in urban areas exhibit complex spatial patterns due to the impact of street configurations, mobile sources, and human activities. However, a comprehensive understanding of these patterns, which involve complex interactions, is still lacking due to the human perspective of road interface characteristics has not been taken into account. In this study, a mobile travel platform was constructed to collect both on-road navigation Street View Panoramas (OSVPs) and the corresponding CO2 concentrations. >100 thousand sample pairs that matched "street view-CO2 concentration" were obtained, covering 675.8 km of roads in Shenzhen, China. In addition, four ensemble learning (EL) models were utilized to establish nonlinear connections between the semantic and object features of streetscapes and CO2 concentrations. After performing EL fusion modeling, the predictive R2 in the test set exceeded 90 %, and the mean absolute error (MAE) was <3.2 ppm. The model was applied to Baidu Street View Panoramas (BSVPs) in Shenzhen to generate a map of average on-road CO2 with a 100 m resolution, and the Local Indicator of Spatial Association (LISA) was then used to identify high CO2 intensity spatial clusters. Additionally, the Light Gradient Boost-SHapley Additive exPlanation (LGB-SHAP) analysis revealed that vertically planted trees can reduce CO2 emissions from on-road sources. Moreover, the factors that affect on-road CO2 exhibit interaction and threshold effects. Street View Panoramas (SVPs) and Artificial Intelligence (AI) were adopted here to enhance the spatial measurement of on-road CO2 concentrations and the understanding of driving factors. Our approach facilitates the assessment and design of low-emission transportation in urban areas, which is critical for promoting sustainable traffic development.

Taste-Active Peptides from Triple-Enzymatically Hydrolyzed Straw Mushroom Proteins Enhance Salty Taste: An Elucidation of Their Effect on the T1R1/T1R3 Taste Receptor via Molecular Docking.

The objective of our study was to analyze and identify enzymatic peptides from straw mushrooms that can enhance salty taste with the aim of developing saltiness enhancement peptides to reduce salt intake and promote dietary health. We isolated taste-related peptides from the straw mushroom extract using ultrafiltration and identified them using UPLC-Q-TOF-MS/MS. The study found that the ultrafiltration fraction (500-2000 Da) of straw mushroom peptides had a saltiness enhancement effect, as revealed via subsequent E-tongue and sensory analyses. The ultrafiltration fractions (500-2000 Da) were found to contain 220 peptides, which were identified through UPLC-Q-TOF-MS/MS analysis. The interaction of these peptides with the T1R1/T1R3 receptor was also assessed. The investigation highlighted the significant involvement of Asp223, Gln243, Leu232, Asp251, and Pro254 in binding peptides from triple-enzymatically hydrolyzed straw mushrooms to T1R1/T1R3. Based on the binding energy and active site analysis, three peptides were selected for synthesis: DFNALPFK (-9.2 kcal/mol), YNEDNGIVK (-8.8 kcal/mol), and VPGGQEIKDR (-8.9 kcal/mol). Importantly, 3.2 mmol of VPGGQEIKDR increased the saltiness level of a 0.05% NaCl solution to that of a 0.15% NaCl solution. Additionally, the addition of 0.8 mmol of YNEDNGIVK to a 0.05% NaCl solution resulted in the same level of saltiness as a 0.1% NaCl solution.

Flash extraction of ulvan polysaccharides from marine green macroalga Ulva linza and evaluation of its antioxidant and gut microbiota modulation activities.

In this study, flash extraction was used to rapidly extract water-soluble polysaccharides from Ulva linza. The optimal extraction process for the flash extraction was determined by Box-Behnken design with extraction temperature 80 °C, extraction time 117 s, liquid-solid ratio 46:1 (mL/g) and a corresponding yield of 18.5 %. The crude Ulva linza polysaccharides (CULP) were subsequently isolated by chromatography technology to obtain purified Ulva linza polysaccharide (ULP) and characterized by monosaccharide composition and molecular weight determination analysis. Furthermore, the antioxidant bioactivity of ULP was studied and the results revealed that it had a good scavenging effect on DPPH, ABTS and OH, with IC50 values of 149.2 µg/mL, 252.5 µg/mL and 1073 µg/mL, respectively. After in vitro fermentation by human fecal microbiota, the pH value of fermentation culture significantly decreased to 5.06, suggesting that ULP could be hydrolyzed and utilized by gut microbiota. The abundance of beneficial bacteria including Bacteroides, Parabacteroides and Faecalibacterium was improved. Meanwhile, the relative abundance of Prevotella, Blautia and Ruminococcus was decreased, and the low ratio of these organisms might reveal positive effects on maintaining the balance of gut microbial biodiversity. These results suggested that the composition of the human gut microbiota could be modulated by ULP, and ULP might possess the potential to maintain gut homeostasis and improve human intestinal health.

Exploring novel Kokumi peptides in Agaricus bisporus: selection, identification, and tasting mechanism investigation through sensory evaluation and computer simulation analysis.

Agaricus bisporus contains amino acids associated with thickness and full-mouthfeel, making it a potential candidate for salt substitutes and flavor enhancers in various food applications. Kokumi peptides were isolated from the enzymatic digest of Agaricus bisporus using ultrafiltration nanofiltration, gel chromatographic separation, and RP-HPLC, coupled with sensory evaluation. Subsequently, the peptides, EWVPVTK and EYPPLGR, were selected for solid-phase synthesis based on molecular docking. Sensory analysis, including thresholds, time intensity, and dose-configuration relationships, indicated that EWVPVTK and EYPPLGR exhibited odor thresholds of 0.6021 mmol L-1 and 2.332 mmol L-1 in an aqueous solution. Molecular docking scores correlated with low sensory thresholds, signifying strong taste sensitivities. EWVPVTK, in particular, demonstrated a higher sense of richness at lower concentrations compared to EYPPLGR. Molecular docking and dynamics simulations elucidated that the interactions between Kokumi peptides and the CaSR receptor primarily involved hydrogen bonding, electrostatic interactions, and hydrophobic interactions. Both EWVPVTK and EYPPLGR exhibited stable binding to the CaSR receptor. Active binding sites were identified, with EWVPVTK interacting at Arg 66, Asp 216, Gln 245, and Asn 102, while EYPPLGR engaged with Ser 272, Gln 193, Glu 297, Ala-298, Tyr-2, and Agr-66 in hydrophilic interactions through hydrogen bonds. Notably, these two Kokumi peptides were found to be enriched in umami and sweet amino acids, underscoring their pivotal role in umami perception. This study not only identifies novel Kokumi peptides from Agaricus bisporus but also contributes theoretical foundations and insights for future studies in the realm of Kokumi peptides.

Novel kokumi peptides from yeast extract and their taste mechanism via an in silico study.

Yeast extract, a widely utilized natural substance in the food industry and biopharmaceutical field, holds significant potential for flavor enhancement. Kokumi peptides within yeast extracts were isolated through ultrafiltration and gel chromatography, followed by identification using liquid chromatography tandem mass spectrometry (LC-MS/MS). Two peptides, IQGFK and EDFFVR, were identified and synthesized using solid-phase methods based on molecular docking outcomes. Sensory evaluations and electronic tongue analyses conducted with chicken broth solutions revealed taste thresholds of 0.12 mmol L-1 for IQGFK and 0.16 mmol L-1 for EDFFVR, respectively, and both peptides exhibited kokumi properties. Additionally, through molecular dynamics simulations, the binding mechanisms between these peptides and the calcium-sensing receptor (CaSR) were explored. The findings indicated stable binding of both peptides to the receptor. IQGFK primarily interacted through electrostatic interactions, with key binding sites including Asp275, Asn102, Pro274, Trp70, Tyr218, and Ser147. EDFFVR mainly engaged via van der Waals energy and polar solvation free energy, with key binding sites being Asp275, Ile416, Pro274, Arg66, Ala298, and Tyr218. This suggests that both peptides can activate the CaSR, thereby inducing kokumi activity. This study provides a theoretical foundation and reference for the screening and identification of kokumi peptides, successfully uncovering two novel kokumi peptides derived from yeast extract.

Impact of Leavening Agents on Flavor Profiles and Microbial Communities in Steamed Bread: A Comparative Analysis of Traditional Chinese Sourdough and Commercial Yeast.

Chinese steamed bread (CSB) made with commercial yeasts and traditional Chinese sourdoughs was analyzed for the flavor and microbial communities. Sensory attributes were assessed using quantitative descriptive analysis (QDA). Results showed that commercial yeast CSB-1 (JMMT1), a yeast-based sample, had stronger milky and sweet attributes, while commercial yeast CSB-2 (JMMT2) had more pronounced yeasty attributes. Among the sourdough-based samples, Shandong traditional sourdough steamed bread (SDMT) exhibited a winelike character with a weak sweet aftertaste, whereas Shanxi traditional sourdough steamed bread (SXMT) had a distinct sour attribute and a less prominent floury taste. SAFE-GC-O-MS analysis identified 40 aroma compounds with FD values ≥2, including 33 key aroma compounds with an OAV of ≥1. Compounds such as 2,3-butanediol, decanal, methyl isobutenyl ketone, gamma-nonanolactone, ethyl caprate, 2-ethylhexyl acetate, vanillin, and indole contributed significantly to the diverse aroma profiles. High-throughput sequencing revealed dominant strains: Bacillus in JMMT1, Lactobacillus in JMMT2, Bacillus in SDMT, and Lactobacillus in SXMT. Over two-thirds of the aroma compounds showed correlations with microorganisms. Notably, Acetobacter exhibited a highly significant correlation with butanoic acid, while Lactobacillus played a significant role in the formation of ester flavors. These findings contribute to the flavor evaluation and microbial community analysis of steamed bread made with different leavening agents, providing valuable insights into their relationship.

Analysis of umami taste and their contributing compounds in edible fungi based on electronic tongue, sensory evaluation, and chemical analysis.

Edible fungi are rich in nutrients and have unique umami taste, which varies with genotypes, growth conditions, and harvest time. In this study, umami compounds in 12 species of edible fungi are analyzed and identified by electronic tongue. Through principal component analysis and discriminant factor analysis, these 2 methods could be successfully distinguished the variety of 12 edible fungi. Besides, the umami intensity of edible fungi soup is also evaluated by sensory and chemical analysis methods, for example, Tricholoma matsutake is 5.60 ± 0.34 and 5.17 ± 0.38, Coprinus comatus is 7.70 ± 0.23 and 9.83 ± 0.34 through sensory evaluation and electronic tongue respectively, followed by establishing the correlation from the response data by PLS (partial least squares analysis). According to the PLS model, with a correlation coefficients of calibration models greater than 0.7 and the low root mean square error of calibration and root mean square error of prediction values, the results correlate well with each other. Therefore, we can indicate that the electronic tongue is able to analyze and evaluate the umami intensity of edible fungi to some extent.

Exploration on dynamics in a discrete predator-prey competitive model involving feedback controls.

In this work, we set up a new discrete predator-prey competitive model with time-varying delays and feedback controls. By virtue of the difference inequality knowledge, a sufficient condition which guarantees the permanence of the established discrete predator-prey competitive model with time-varying delays and feedback controls is derived. Under some appropriate parameter conditions, we have proved that the periodic solution of the system without delay exists and globally attractive. To verify the correctness of the derived theoretical fruits, we give two examples and execute computer simulations. Our obtained results are novel and complement previous known results.

The menstrual cycle regularity and skin: irregular menstrual cycle affects skin physiological properties and skin bacterial microbiome in urban Chinese women.

BACKGROUND: The regularity of the menstrual cycle directly affects women's health. Many studies have focused on menstrual health; however, menstrual cycle regularity-related variations in skin physiological characteristics and skin microbiota have been seldom investigated. METHODS: To investigate the menstrual cycle regularity-related variations in skin physiological characteristics and skin microbiota of 197 cases of Chinese women aged 18-35 years living in shanghai in 2021. Based on a self-evaluation questionnaire, the volunteers were divided into three groups C1 (those with a regular menstrual cycle), C2 (those with a less regular menstrual cycle) and C3 (those with an irregular menstrual cycle). The physiological parameters of facial skin were measured by non-invasive methods and the skin microbiome was analyzed by 16S rRNA high-throughput sequencing. RESULTS: In the C3 group, the hydration content was significantly decreased (p < 0.05), the TEWL was significantly increased (p < 0.05), and the sebum content was increased (p > 0.05), indicating that the skin barrier integrity weakened with increased menstrual cycle irregularity. Additionally, the melanin level, L value and b value were significantly decreased (p < 0.05) in the C3 group, but the a value was significantly increased (p < 0.001), which indicated that the skin color became darker. Furthermore, the skin microbiota diversity decreased with increasing cycle irregularity, but the differences were not significant. The skin microbiota composition showed that the proportion of Firmicutes, Acinetobacter, Staphylococcus and Cutibacterium were increased in those with an irregular menstrual cycle, indicating that alterations in the ratio of bacterial phyla and/or genera might disturb skin homeostasis. Spearman correlation analysis revealed strong correlations between the microbiota and skin physiological parameters. Based on the associations among hormones, skin physiological parameters and skin microbiota, it is possible that the skin physiological parameters, as well as the skin microbial diversity and composition, change with hormonal fluctuations during the menstrual cycle. CONCLUSIONS: An irregular menstrual cycle can affect skin physiological characteristics and the skin microbiota. Female with an irregular menstrual cycle should strengthen skin care practices and use skin care products with moisturising and soothing effects to protect their skin.

Revealing the influence of microbiota on the flavor of kombucha during natural fermentation process by metagenomic and GC-MS analysis.

In this work, raw Pu-erh tea (RAPT) was employed for kombucha preparation, and the microbial composition and volatile flavor compounds of the fermented tea had been investigated during natural fermentation process. The head space-solid phase microextraction-gas chromatograph mass spectrometry (HS-SPME-GC-MS) was performed for volatiles analysis of unfermented tea and kombucha fermented for 3 days (KF-3) and 6 days (KF-6). Meanwhile, the microbial community of KF-3 and KF-6 were evaluated by metagenomic analysis. A total of 72 volatile compounds were identified and obvious changes in volatiles were observed during the fermentation process based on the results of GC-MS and principal component analysis (PCA). Metagenomic sequencing analysis demonstrated that bacterium Komagataeibacter saccharivorans and unclassified-g-komagataeibacter and yeast Saccharomyces cerevisiae and Brettanomyces bruxellensis were the most common microbes contained in the sampled kombucha communities. Furthermore, the relevance among microbial community and volatile compounds was evaluated through correlation heatmap analysis. The results suggested that the main flavor volatiles of kombucha (i.e., acids, esters and terpenes) were closely related to species of genus Komagataeibacter, Gluconacetobacter, Saccharomyces, Brettanomyces, Acetobacter, Novacetimonas and Pichia microorganisms. The obtained results would help to better understand microbial communities and volatile compounds of kombucha, which could provide useful information for enhancing the flavor quality of kombucha products.

Melatonin promotes the development of the secondary hair follicles by regulating circMPP5.

BACKGROUND: The quality and yield of cashmere fibre are closely related to the differentiation and development of secondary hair follicles in the skin of cashmere goats. The higher the density of secondary hair follicles, the higher the quality and yield of cashmere from the fleece. Development of secondary hair follicles commences in the embryonic stage of life and is completed 6 months after birth. Preliminary experimental results from our laboratory showed that melatonin (MT) treatment of goat kids after their birth could increase the density of secondary hair follicles and, thus, improve the subsequent yield and quality of cashmere. These changes in the secondary hair follicles resulted from increases in levels of antioxidant and expression of anti-apoptotic protein, and from a reduction in apoptosis. The present study was conducted to explore the molecular mechanism of MT-induced secondary hair follicle differentiation and development by using whole-genome analysis. RESULTS: MT had no adverse effect on the growth performance of cashmere kids but significantly improved the character of the secondary hair follicles and the quality of cashmere, and this dominant effect continued to the second year. Melatonin promotes the proliferation of secondary hair follicle cells at an early age. The formation of secondary hair follicles in the MT group was earlier than that in the control group in the second year. The genome-wide data results involved KEGG analysis of 1044 DEmRNAs, 91 DElncRNAs, 1054 DEcircRNAs, and 61 DEmiRNAs which revealed that the mitogen-activated protein kinase (MAPK) signaling pathway is involved in the development of secondary hair follicles, with key genes (FGF2, FGF21, FGFR3, MAPK3 (ERK1)) being up-regulated and expressed. We also found that the circMPP5 could sponged miR-211 and regulate the expression of MAPK3. CONCLUSIONS: We conclude that MT achieves its effects by regulating the MAPK pathway through the circMPP5 sponged the miR-211, regulating the expression of MAPK3, to induce the differentiation and proliferation of secondary hair follicle cells. In addition there is up-regulation of expression of the anti-apoptotic protein causing reduced apoptosis of hair follicle cells. Collectively, these events increase the numbers of secondary hair follicles, thus improving the production of cashmere from these goats.

Insights into the Edible and Biodegradable Ulvan-Based Films and Coatings for Food Packaging.

Recently, edible films or coatings that are made from algal polysaccharides have become promising candidates for replacing plastic-based packaging materials for food storage due to their non-toxic, biodegradable, biocompatible, and bioactive characteristics. Ulvan, a significant biopolymer with unique functional properties derived from marine green algae, has been extensively used in various sectors. However, there are fewer commercial applications of this sugar in the food packaging industry compared to many other algae-derived polysaccharides, such as alginates, carrageenan, and agar. This article aims to review the unparalleled chemical composition/structure and physiochemical properties of ulvan and the latest developments in ulvan-based edible films and coatings, thus highlighting their potential applications in the food packaging industry.

Hair Follicle Development and Cashmere Traits in Albas Goat Kids.

The objectives of this trial were to study the growth and development of hair follicles and cashmere traits in cashmere goats and to provide a theoretical basis for the regulation of secondary hair follicle development and the scientific breeding selection of cashmere goats. Twelve single-fetal female kids were selected as research objects. A long-term tracking plan was created to regularly determine their growth performance, cashmere performance, and hair follicle traits. The results showed no significant difference in live weight after the first and second combing. The cashmere yield and unit yield of the first combing were significantly higher than those of the second combing (p < 0.05). Sections of hair follicles showed that the primary hair follicles are almost fully developed by 1 month, and the secondary hair follicles are fully developed by 5-6 months after birth. The primary hair follicle density (PFD) and secondary hair follicle density (SFD) were highest at birth and decreased within 1 month; and SFD was stable at 5-6 months of age. The change of MSFD took a maximum time of 2 to 3 months. The S:P increase reached its peak at 6 months. BMP4 expression increased with time. FGF2, FGF21 and BMP7 were higher at 3 months old than at the other two-time points. In conclusion, this study determined the total development time of primary and secondary hair follicles from morphology and speculated that FGF2, FGF21, and BMP7 may play a regulatory role in developing secondary hair follicles. Therefore, the period from birth to 6 months of age was the best time to regulate secondary hair follicle development in cashmere goats kids. The traits of the hair follicle and cashmere at 6 months of age could be breeding selection indicators for cashmere goats.

Melatonin Promotes the Development of Secondary Hair Follicles in Adult Cashmere Goats by Activating the Keap1-Nrf2 Signaling Pathway and Inhibiting the Inflammatory Transcription Factors NFκB and AP-1.

Exogenous melatonin (MT) has been used to promote the growth of secondary hair follicles and improve cashmere fiber quality, but the specific cellular-level mechanisms involved are unclear. This study was carried out to investigate the effect of MT on the development of secondary hair follicles and on cashmere fiber quality in cashmere goats. The results showed that MT improved secondary follicle numbers and function as well as enhanced cashmere fiber quality and yield. The MT-treated goat groups had high secondary-to-primary ratios (S:P) for hair follicles, greater in the elderly group (p < 0.05). Antioxidant capacities of secondary hair follicles improved fiber quality and yield in comparison with control groups (p < 0.05/0.01). Levels of reactive oxygen and nitrogen species (ROS, RNS) and malondialdehyde (MDA) were lowered (p < 0.05/0.01) by MT. There was significant upregulation of antioxidant genes (for SOD-3; GPX-1; NFE2L2) and the protein of nuclear factor (Nrf2), and downregulation of the Keap1 protein. There were significant differences in the expression of genes for secretory senescence-associated phenotype (SASP) cytokines (IL-1ß, IL-6, MMP-9, MMP-27, CCL-21, CXCL-12, CXCL-14, TIMP-1,2,3) plus their protein of key transcription factors, nuclear factor kappa B (NFκB) and activator protein-1 (AP-1), in comparison with the controls. We concluded that MT could enhance antioxidant capacity and reduce ROS and RNS levels of secondary hair follicles through the Keap1-Nrf2 pathway in adult cashmere goats. Furthermore, MT reduced the expression of the SASP cytokines genes by inhibiting the protein of NFκB and AP-1 in the secondary hair follicles in older cashmere goats, thus delaying skin aging, improving follicle survival, and increasing the number of secondary hair follicles. Collectively, these effects of exogenous MT enhanced the quality and yield of cashmere fibers, especially at 5-7 years old.

Novel umami peptide from Hypsizygus marmoreus hydrolysate and molecular docking to the taste receptor T1R1/T1R3.

Hypsizygus marmoreus is an edible variety of mushroom with a distinct umami taste, which might be contributed by amino acids and umami peptides. Umami peptides have been widely studied, except for those from Hypsizygus marmoreus. Therefore, the main purpose of this study was to find new umami peptides in it. After the mushrooms were enzymatically hydrolyzed, they were separated and characterized by UF, GFC, RP-HPLC, UPLC-Q-TOF MS/MS and the umami peptide EGTAG was obtained. Sensory evaluation found that EGTAG had distinct umami taste with thresholds of 8.26 mmol/L and 10.04 mmol/L in water and chicken consommé, respectively. Molecular docking results showed that Glu120, Ser142, Asp162 and Gln361 of T1R1/T1R3 may play critical roles. Hydrogen and hydrophobic interactions were the main binding forces between T1R1/T1R3 and the umami peptide. We proposed umami peptide from Hypsizygus marmoreus may be used as savory enhancer in the salt-reducing foods in the future. HYPOTHESES: Edible fungi generally have umami taste and umami peptides from edible fungi had been reported in the literature. Hypsizygus marmoreus belongs to edible fungi and has umami characteristics, so it can be inferred that Hypsizygus marmoreus contains umami peptides.

Identification of novel umami peptides from Boletus edulis and its mechanism via sensory analysis and molecular simulation approaches.

The study aimed to identify umami peptides from Boletus edulis and explore their umami mechanism. 421, 713 and 616 peptides identified by LC-MS/MS from control sample (CS), enzymatically extracted sample (EES) and high-pressure cooking sample (HPCS), respectively. According to molecular docking study, three potential umami peptides (DGF, KCGQ and HHYE) were chemically synthesized for sensory evaluation. DGF/HHYE had the lowest umami recognition threshold values in the absence (0.37 mmol/L for DGF)/presence (0.21 mmol/L for HHYE) of monosodium l-glutamate. KCGQ exhibited the strongest synergistic umami effect. Molecular dynamic simulation revealed that hydrogen bonds and hydrophobic interactions were the major intermolecular interaction forces and the charged amino acid residues (D1, E4 and K1) in umami peptides were dominate in the molecular recognition of umami peptides and the receptor. This study lays the groundwork for the efficient screening of umami peptides from edible fungi and contributes to the umami peptides structure-activity relationship research.

Characteristic volatile fingerprints of three edible marine green algae (Ulva spp.) in China by HS-GC-IMS and evaluation of the antioxidant bioactivities.

In this study, the volatile compounds fingerprinting as well as the relationship between phytochemical composition and antioxidant bioactivity of U. prolifera, U. linza and U. clathrata were investigated. The significant differences of volatile compounds in three dehydrated seaweeds were observed by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), and the type of volatile compounds in U. clathrata (83 compounds) was highest, followed by U. linza (75 compounds) and U. prolifera (57 compounds). Furthermore, a variety of polarity solvents were used to extract Ulva spp. in order to determine the influence of total phenolics (TPC), flavonoids (TFC) and carbohydrates content (TCC) on antioxidant activities. The results showed that ethyl acetate extracts of U. prolifera had the highest antioxidant activity (IC50 = 143.18 µg/mL) in ABTS assay, and methanol extracts of U. clathrata revealed the highest scavenging activity (IC50 = 95.32 µg/mL) against OH radicals as well as the aqueous extracts of U. prolifera exhibited the strongest radical scavenging capacity (IC50 = 527.75 µg/mL) against DPPH radicals. Pearson correlation analysis revealed that the antioxidant capacity of Ulva spp. was significantly impacted by TFC and TPC. The findings presented in this thesis add to our understanding of volatilization characteristics and biological properties in edible marine green seaweeds.

New exploration on bifurcation for fractional-order quaternion-valued neural networks involving leakage delays.

During the past decades, many works on Hopf bifurcation of fractional-order neural networks are mainly concerned with real-valued and complex-valued cases. However, few publications involve the quaternion-valued neural networks which is a generalization of real-valued and complex-valued neural networks. In this present study, we explorate the Hopf bifurcation problem for fractional-order quaternion-valued neural networks involving leakage delays. Taking advantage of the Hamilton rule of quaternion algebra, we decompose the addressed fractional-order quaternion-valued delayed neural networks into the equivalent eight real valued networks. Then the delay-inspired bifurcation condition of the eight real valued networks are derived by making use of the stability criterion and bifurcation theory of fractional-order differential dynamical systems. The impact of leakage delay on the bifurcation behavior of the involved fractional-order quaternion-valued delayed neural networks has been revealed. Software simulations are implemented to support the effectiveness of the derived fruits of this study. The research supplements the work of Huang et al. (Neural Netw 117:67-93, 2019).

Variation in Volatile Compounds of Raw Pu-Erh Tea upon Steeping Process by Gas Chromatography-Ion Mobility Spectrometry and Characterization of the Aroma-Active Compounds in Tea Infusion Using Gas Chromatography-Olfactometry-Mass Spectrometry.

Steeping process is an important factor for aroma release of tea, which has rarely been investigated for the aroma changes of raw Pu-erh tea (RAPT). In addition, the comprehensive aroma characteristics identification of RAPT infusion is necessary. In this study, GC-IMS coupled with principal component analysis (PCA) was used to clarify the difference of volatile profiles during the steeping process of RAPT. Furthermore, the volatiles contained in the RAPT infusion were extracted by three pretreatment methods (HS-SPME, SBSE, and SAFE) and identified using GC-O-MS. According to the odor activity value, 28 of 66 compounds were categorized as aroma-active compounds. Aroma recombination and omission experiments showed that "fatty", "green", "fruity", and "floral" are considered to be the main aroma attributes of RAPT infusion with a strong relationship with 1-octen-3-one, 1-octen-3-ol, (E)-2-octenal, ß-ionone, linalool, etc. This study will contribute a better understanding of the mechanism of the RAPT steeping process and volatile generation.

Geographical differentiation of Molixiang table grapes grown in China based on volatile compounds analysis by HS-GC-IMS coupled with PCA and sensory evaluation of the grapes.

In this study, the volatile fingerprints of GC-IMS showed great differences on the volatile profiles of Molixiang grapes collected from three different regions of China, which suggested that aroma of table grapes could be largely impacted by origin areas. Butyl lactate, E-2-octenal and Z-2-pentanol were mainly contained in MLX-A, the grapes sampled from Ningbo, China. High contents of p-cymene, styrene and γ-terpinene were observed in MLX-B grapes sampled from Beizhen, China. In addition, benzaldehyde and methyl benzoate were major contained in MLX-C grapes sampled from Zhangzhou, China. The PCA results revealed effective differentiation of samples from different geographical origin based on the information obtained from GC-IMS. Furthermore, sensory evaluation showed that the aroma characters of grapes from different geographical origin were significantly different (P ≤ 0.05). E-2-octenal, styrene and benzaldehyde might serve as the geographical marker compounds of origin area based on the results of GC-IMS analysis and sensory evaluation.