Search Results (5,538)

Purple corn pericarp, a processing waste stream, is an extremely rich source of phytochemicals. Optimal polyphenol extraction parameters were identified using response surface methodology (RSM) by combining a deep eutectic solvent (DES) and ultrasound-assisted extraction (UAE) method. After DES characterization, Plackett–Burman design was used to screen five explanatory variables, namely, time, Temp (temperature), water, Amp (amplitude), and S/L (solid-to-liquid ratio). The total anthocyanin concentration (TAC), total polyphenol concentration (TPC), and condensed tannin (CT) concentration were the response variables. After identifying significant factors, the Box–Behnken design was utilized to identify the optimal extraction parameters. The experimental yields under the optimized conditions of time (10 min), temperature (60 °C), water concentration (42.73%), and amplitude (40%) were 36.31 ± 1.54 g of cyanidin-3-glucoside (C3G), 103.16 ± 6.17 g of gallic acid (GA), and 237.54 ± 9.98 g of epicatechin (EE) per kg of pericarp, with a desirability index of 0.858. The relative standard error among the predicted and experimental yields was <10%, validating the robustness of the model. HPLC analysis identified seven phytochemicals, and significant antioxidant activities were observed through four distinct assays. Metabolomic profiling identified 57 unique phytochemicals. The UAE technique combined with DES can efficiently extract polyphenols from purple corn pericarp in a short time. Full article

This contribution presents a personal perspective on the development of thermo-photocatalytic schemes. It discusses several concepts focused on the common presentation of catalytic and thermo-photocatalytic data, with special emphasis on the determination of TOF (Turnover Frequency) and Quantum Efficiency parameters. The importance of including temperature profiles and photon absorption rates in the analysis for intrinsic kinetic studies, comparison of catalytic results, and the potential scaling of reactors is highlighted. Additionally, topics related to the efficiency of the use of radiation and heat transfer are discussed. Photon absorption profiles are presented for a TiO₂ catalytic surface of 20 × 20 cm (both fluorescent and LED configuration), as well as the temperature profile obtained using a thermal resistance with a diameter of 5 cm in a flat reactor. Using this example, the importance of designing thermo-photocatalytic systems to ensure an acceptable level of homogeneity in light irradiation and temperature is discussed. The discussion provides data that positions thermo-photocatalytic processes in the early stages of research. It is still necessary to advance the understanding of phenomena occurring under mixed temperature and light conditions. Additionally, new materials that meet the required characteristics for each application need to be developed, along with the design of new thermo-photocatalytic reactors. Full article

Beer is one of the most popular alcoholic beverages globally, leading to continuous efforts to enhance its production methods. Raw materials and the production process are crucial in the brewing industry, with fermentation being a vital stage that significantly impacts beer quality. The aim of this study is to optimize the beer fermentation process by maximizing the ethanol concentration while minimizing species that adversely affect the organoleptic properties of beer. A novel optimization approach has been developed to derive an optimal, smooth, and continuous temperature profile that can be directly applied in real-world processes. This method integrates Fourier series and orthogonal polynomials for control action parameterization, in combination with evolutionary algorithms for parameter optimization. A key advantage of this methodology lies in its ability to handle a reduced parameter set efficiently, resulting in temperature profiles that are continuous and differentiable. This feature eliminates the need for post-smoothing and is particularly advantageous in biotechnological applications, where abrupt changes in temperature could negatively affect the viability of microorganisms. The optimized profiles not only enhance fermentation efficiency, but also improve the ethanol yield and reduce undesirable flavor compounds, providing a substantial improvement over current industrial practices. These advancements present significant potential for improving both the quality and consistency of beer production. Full article

Yakutia is one of the coldest permanently inhabited regions in the world, characterized by a subarctic climate with average January temperatures near −40 °C and the minimum below −60 °C. Recently, we demonstrated accelerated epigenetic aging of the Yakutian population in comparison to their Central Russian counterparts, residing in a considerably milder climate. In this paper, we analyzed these cohorts from the inflammaging perspective and addressed two hypotheses: a mismatch in the immunological profiles and accelerated inflammatory aging in Yakuts. We found that the levels of 17 cytokines displayed statistically significant differences in the mean values between the groups (with minimal p-value = 2.06 × 10⁻¹⁹), and 6 of them are among 10 SImAge markers. We demonstrated that five out of these six markers (PDGFB, CD40LG, VEGFA, PDGFA, and CXCL10) had higher mean levels in the Yakutian cohort, and therefore, due to their positive chronological age correlation, might indicate a trend toward accelerated inflammatory aging. At the same time, a statistically significant biological age acceleration difference between the two cohorts according to the inflammatory SImAge clock was not detected because they had similar levels of CXCL9, CCL22, and IL6, the top contributing biomarkers to SImAge. We introduced an explainable deep neural network to separate individual inflammatory profiles between the two groups, resulting in over 95% accuracy. The obtained results allow for hypothesizing the specificity of cytokine and chemokine profiles among people living in extremely cold climates, possibly reflecting the effects of long-term human (dis)adaptation to cold conditions related to inflammaging and the risk of developing a number of pathologies. Full article

Habanero pepper (Capsicum chinense) is known for its heat and culinary uses, especially in Mexico’s Yucatán Peninsula. Its leaves, rich in bioactive compounds like polyphenols with antioxidants and anti-inflammatory properties, have been traditionally used in medicinal practices and are gaining interest for health benefits. Efficient green extraction methods, such as natural deep eutectic solvents (NADES), combined with microencapsulation, can improve the stability and application of these compounds in functional foods and nutraceuticals. This study aimed to determine the optimal microencapsulation parameters using response surface methodology, implementing a 2² central composite design with 4 central points of habanero leaf extracts obtained by sonic probe with NADES. The factors evaluated were the percentage of guar gum (5%, 7.5%, and 10%) and the drying temperature (80 °C, 90 °C, and 100 °C). The extracts were spray-dried with maltodextrin (DE17-20), guar gum, and modified starch as encapsulating agents. The total polyphenol content (TPC), polyphenol profile, and antioxidant capacity methods like 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) or ABTS were analyzed. The best results for TPC and ABTS antioxidant capacity were achieved using 7.5% guar gum (GG) at 90 °C. At 104 °C, with the same GG concentration, the microcapsules maintained a high antioxidant capacity. Optimal conditions for TPC, DPPH, and neohesperidin were identified as 7.8% GG/89.4 °C, 8.06% GG/104.1 °C, and 4% GG/75.85 °C, respectively. The resulting powder exhibited high polyphenol content and antioxidant capacity, highlighting successful microencapsulation. Full article

To determine the optimal conditions of pressurized liquid extraction (PLE) and microwave-assisted extraction (MAE) of polyphenols from black chokeberry leaves (BCL), temperature, time and sample-to-solvent ratio (SSR) were varied to obtain maximum polyphenols yield. The extracts were analyzed for total polyphenols (TP) as well as individual ones (UPLC ESI MS²) and antioxidant capacity (FRAP, DPPH and ORAC). Moreover, the biological activity of the selected extracts was additionally determined. The optimal PLE and MAE conditions were 150 °C, 5 min extraction time and SSR 1:30 g/mL (TP 80.0 mg GAE/g dm), and 70 °C, extraction time 5 min and SSR 1:30 g/mL (TP 36.4 mg GAE/g dm), respectively. Both methods yielded similar polyphenol profiles (43 compounds) but differed quantitatively. MAE extracts contained more flavonols and phenolic acids, while PLE extracts had higher procyanidins and flavan-3-ols. Furthermore, the PLE extract exhibited a superior antioxidant capacity. This BCL extract also showed that it can protect against oxidative and DNA damage and can induce free radical formation and DNA damage, albeit at different doses. Moreover, it had a moderate antimicrobial activity against S. aureus and B. subtilis, while no antimicrobial activity was observed against Gram-negative bacteria as well as yeasts, lactic acid bacteria and molds. Full article

To evaluate the effects of mussel meal, as a sustainable ingredient for fish feed, on the growth, health status, proximate composition, and fatty acid profile of gilthead seabream, mussel meal was included in commercial feed formulations. Sunflower oil (2%) was used as a binding agent. Four groups of gilthead seabream were fed either with control feed (commercial feed, commercial feed and sunflower oil) or mussel-meal-supplemented formulations (commercial feed, sunflower oil, and 2.5 or 5% mussel meal) for six weeks. In this experiment, a total of 180 specimens of gilthead seabream juveniles were included. The initial weight and length of the gilthead seabream specimens were, on average, 13.04 g and 9.57 cm, respectively. The average temperature of the seawater ranged between 25 and 26 °C during the experiment. The results of this study indicated a higher relative weight gain and a slightly lower feed conversion ratio in the control group fed with commercial feed, probably because of macronutrient imbalances introduced by the addition of mussel meal and sunflower oil. The groups fed with mussel-supplemented diets had a slightly lower crude protein content compared to the group fed with a commercial diet. The addition of sunflower oil and mussel meal decreased the saturated fatty acid content while increasing the monounsaturated and polyunsaturated fatty acid content compared to the control group. However, the high content of DHA and EPA in the mussel meal resulted in a proportional increase of these fatty acids in the muscle tissue of gilthead seabream, although the overall effect was not statistically significant. The findings of this study suggest that mussel meal is a promising source of protein and lipids for sustainable fish feed production, but under the experimental setup, mussel meal did not act as an attractant for increasing fish feed intake during the summer conditions. Full article

Real-time and accurate construction of regional sound speed profiles (SSPs) is important for building underwater positioning, navigation, and timing (PNT) systems as it greatly affects signal propagation modes. In this paper, we summarize and analyze the current research status in the field of underwater SSP construction, where the mainstream methods include direct SSP measurement and SSP inversion. For the direct measurement method, we compare the performance of popular international and commercial brands of temperature, conductivity, and depth profilers (CTDs). For the inversion methods, the framework and basic principles of matched field processing (MFP), compressive sensing (CS), and deep learning (DL) are introduced, and their advantages and disadvantages are compared. Presently, SSP inversion relies on sonar observation data, limiting its applicability to areas that can only be reached by underwater observation systems. Furthermore, these methods are unable to predict the distribution of sound velocity in future time. Therefore, the mainstream trend in future research on SSP construction will involve comprehensive utilization of multi-source data to offer elastic sound velocity distribution estimation services for underwater users without the need for sonar observation data. Full article

Estuaries serve as transitional zones between rivers and the ocean, and their mixed dynamic characteristics are crucial for the transport, transformation, and cycling of materials. This study investigates the mixing characteristics and their dominant factors in the Danshui Estuary and thermal discharge outlets through field measurements. Based on CTD (Conductance Temperature Depth) profiles and nutrient concentration measurements, the Danshui Estuary exhibited significant stratification during the October 2016 cruise, while vertical mixing was uniform during the March 2017 cruise. Vertical mixing was suppressed during stratification, but the nutrient concentration varied with salinity in a manner that was similar to non-stratified conditions, generally conforming to the theoretical dilution curve, which means physical mixing dominated here, indicating that horizontal mixing is predominant in the Danshui Estuary. The spatial scale calibrated horizontal dispersion coefficients were measured as 9.16 ± 1.57 m² s⁻¹ and 11.84 ± 1.71 m² s⁻¹ for stratified and non-stratified conditions, respectively, highlighting the Danshui Estuary’s strong horizontal mixing. Thermal discharge outlets are an important type of estuarine environment in non-natural estuaries. The 3D thermohaline structure measured by the underway CTD revealed an upwelling of cold and high-salinity water during the flood tide. The calculated Richardson number during the flood tide was approximately 0.7, indicating a very strong stratification effect. The horizontal dispersion coefficients calibrated by spatial scale showed no significant difference between different tides (flood tide: 0.53 ± 0.18 m² s⁻¹, ebb tide: 0.46 ± 0.17 m² s⁻¹). Therefore, the slower temperature decay during the flood tide, as reflected by the e-folding time (flood tide: 4.19 ± 2.33 min, ebb tide: 2.14 ± 0.40 min), is attributed to the strong stratification. Based on these findings, it is recommended that the power plant mitigates the impact of waste heat on the marine environment by increasing discharge during the ebb tide and reducing it during the flood tide. Full article

The increasing trend of diet-related chronic diseases has stimulated research into developing new food products and beverages with health-promoting potential. At the same time, new resources, including plant by-products, are currently being investigated as a sustainable source of bioactive compounds. In this context, the present study focused on the enrichment of apple juice with anthocyanins and other phenolic compounds by direct ultrasound-assisted extraction (UAE) from bilberry pomace. Response surface methodology combined with a Box–Behnken design was used to find the optimal extraction conditions for maximizing the total anthocyanin content (TAC), total phenolic content (TPC) and DPPH radical scavenging activity (RSA) in the enriched apple juices and to characterize their phenolic profile as influenced by the extraction temperature. UAE from 15% bilberry pomace during 15 min in apple juice at 80 °C resulted in the highest TAC (262.73 mg CGE/L), TPC (1700.91 mg GAE/L) and RSA (8.93 mmol Trolox/L) of the enriched apple juice. The chromatographic polyphenolic profile of the control and enriched juices showed that, besides anthocyanins, phenolic acids (chlorogenic, gallic, caffeic, 3-hydroxybenzoic, p-coumaric, ellagic and protocatechuic acids) and flavonoids (epigallocatechin and catechin) were extracted from the bilberry pomace directly in the apple juice, while the extraction temperature differently impacted the content of individual phenolic compounds. Full article

Discovered within the North Himalayan Metallogenic Belt (NHMB), the Zhaxikang Pb–Zn–Ag–Sb deposit stands as the sole super-large scale ore deposit in the region. This deposit holds significant quantities of Pb and Zn (2.066 million tons at 6.38% average grade), Ag (2661 tons at an average of 101.64 g/t), and Sb (0.235 million tons at 1.14% average grade), making it one of China’s foremost Sb–polymetallic deposits. Stibnite represents the main carrier of Sb in this deposit and has been of great attention since its initial discovery. However, the trace element composition of stibnite in the Zhaxikang deposit has not yet been determined. This study carried out an analysis of the distribution patterns and substitution processes of trace elements within stibnite gathered from the Zhaxikang deposit, aiming to provide crucial information on ore-forming processes. Utilizing high-precision laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), we discovered that the studied stibnite is notably enriched in arsenic (~100 ppm) and lead (~10 ppm). Furthermore, the notably consistent time-resolved profiles suggest that elements such as Fe, Cu, As, In, Sn, Hg, and Pb predominantly exist as solid solutions within stibnite. Consequently, it is probable that the enrichment of Cu, Pb, and Sn in stibnite is due to isomorphic substitution reactions, including 3Pb²⁺↔2Sb³⁺, Cu⁺ + Pb²⁺↔Sb³⁺, and In³⁺ + Sn³⁺↔2Sb³⁺. Apart from that, Mn, Pb, and Hg with the spiky signals indicate their existence within stibnite as micro-inclusions. Overall, we found that the trace element substitutions in stibnite from the Zhaxikang Pb–Zn–Ag–Sb deposit are complicated. Incorporations of trace elements such as Pb, Cu, and In into stibnite are largely influenced by a variety of factors. The simple lattice structure and constant trace elements in studied stibnite indicate a low-temperature hydrothermal system and a relatively stable process for stibnite formation. Full article

Microwave radiometers are passive remote sensing devices that provide important observational data on the state of the oceanic and terrestrial atmosphere. Temperature retrieval accuracy is crucial for radiometer performance. However, inversions during strong convective weather or seasonal phenomena are short-lived and spatially limited, making it challenging for neural network algorithms trained on historical data to invert accurately, leading to significant errors. This paper proposes a long short-term memory (LSTM) network forecast correction model based on the temperature inversion phenomenon to resolve these large temperature inversion errors. The proposed model leverages the seasonal periodicity of atmospheric temperature profiles in historical data to form a circumferential background field, enabling the prediction of expected background profiles for the forecast day based on temporal and spatial continuity. The atmospheric profiles obtained using the radiometer retrieval are compensated with the forecast temperature inversion vector on the forecast day to obtain the final data. In this study, the accuracy of the forecast correction model was verified utilizing meteorological records for the Taizhou area from 2013 to 2017. Using a hierarchical backpropagation network based on the residual module for comparison, which had a forecast accuracy error of 0.0675 K, the error of our new model was reduced by 34% under the temperature inversion phenomenon. Meanwhile, error fluctuations were reduced by 33% compared with the residual network algorithm, improving the retrieval results’ stability in the temperature inversion state. Our results provide insights to improve radiometer remote sensing accuracy. Full article

Temperature and precipitation are important abiotic factors affecting net primary productivity (NPP) in grassland ecosystems. However, findings on how elevation influences the effects of these factors on NPP in alpine grasslands are not yet consistent. In addition, the impact of varied patterns of climate change on NPP sensitivity with elevation remain unclear. Therefore, alpine grassland on the Tibetan Plateau (TP) was selected to profile the spatial and temporal patterns of NPP from 2001 to 2022, and subsequently to reveal the effects of temperature and precipitation on the sensitivity of NPP with altitudinal gradient. The results showed that (1) 91% of the TP grassland experienced positive NPP trends, and the NPP trends followed a unimodal curve with elevation, with the largest mean value at 2500 m; (2) a positive correlation between precipitation and NPP dominated the grassland NPP up to an elevation of 3400 m, and a positive correlation between temperature and NPP dominated the grassland NPP above an elevation of 3400 m; (3) temperature, precipitation, and their interaction explained, on average, 21% of the temporal variation in the NPP of TP grassland, and the explanatory capacity decreased significantly with elevation; and (4) elevation, temperature, and precipitation variations together explained 35% of the NPP sensitivity of the TP grasslands. This study reveals the altitudinal characteristics of NPP in grasslands affected by climate, and reminds us to take elevation into account when carrying out grassland management. Full article

In this article, we report on the alginate heterografted by Poly(N-isopropyl acrylamide-co-N-tert-butyl acrylamide) and Poly(N-isopropyl acrylamide) (ALG-g-P(NIPAM86-co-NtBAM14)-g-PNIPAM) copolymer thermoresponsive hydrogel, reinforced by substituting part of the 5 wt% aqueous formulation by small amounts of Poly(acrylic acid)-g-P(boc-L-Lysine) (PAA-g-P(b-LL)) graft copolymer (up to 1 wt%). The resulting complex hydrogels were explored by oscillatory and steady-state shear rheology. The thermoresponsive profile of the formulations were affected remarkably by increasing the PAA-g-P(b-LL) component of the polymer blend. Especially, the sol-gel behavior altered to soft gel–strong gel behavior due to the formation of a semi-interpenetrating network based on the hydrophobic self-organization of the PAA-g-P(b-LL). In addition, the critical characteristics, namely T_{c,thermothickening} (temperature above which the viscosity increases steeply) and ΔT (transition temperature window), shifted and broadened to lower temperatures, respectively, due to the influence of the hydrophobic side chains P(b-LL) on the LCST of the PNIPAM-based grafted chains of the alginate. The effect of ionic strength was also examined, showing that this is another important factor affecting the thermoresponsiveness of the hydrogel. Again, the thermoresponsive profile of the hydrogel was changed significantly by the presence of salt. All the formulations showed self-healing capability and tolerance injectability, suitable for potential bioapplications in living bodies. Full article

Boldo (Peumus boldus M.), an plant endemic to central and southern Chile, has been recognized as a medicinal herb, especially its leaves that are rich in bioactive compounds with beneficial properties, such as antioxidant, anti-inflammatory, sedative, and antimicrobial properties, among others. This research aimed to evaluate solid-liquid extraction using a response surface methodology to obtain phenolic-rich extracts from boldo leaves and to encapsulate them through spray-drying. A Box-Behnken design was applied to optimize extraction process variables (temperature, time, and solid-liquid ratio). Extracts were characterized in terms of their total phenolic content, with the maximum value obtained being 37.78 mg GAE/g using extraction conditions of a temperature of 100 °C, a time of 60 min, and a solid-liquid ratio of 1:100. The developed microcapsules containing the optimal boldo extracts were characterized (moisture, water activity, scanning electron microscopy, zeta potential, FTIR, total phenolic compounds, antioxidant capacity, and phenolic profile by HPLC-DAD), highlighting their high phenolic content (5.38–5.49 mg GAE/g) and antioxidant capacity, as well as their bioactive content in terms of catechin (445 ± 37 mg/100 g), pyrogallol (304 ± 24 mg/100 g), and epigallocatechin (156 ± 12 mg/100 g). Overall, this study revealed an efficient technique by which to isolate and stabilize bioactive compounds from boldo leaves, with the microcapsules being promising candidates as high added-value ingredients. Full article