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This work reported the application of a twin‐column recycling chromatography system for the separation of three minor impurities in crude aloe‐emodin. The whole process went through three steps, each using a different mobile phase to separate corresponding impurity, which were integrated and automatically operated in a single device. Despite these impurities peaked closely in high‐performance liquid chromatography, they were successfully purified to a content exceeding 97%. In addition, the lab‐scale separation could reach the yields at the mg‐level. The high efficacy should be mainly attributed to the introduction of a small step solvent gradient between the upstream and downstream columns, which helped to counterbalance the band broadening. This report suggested that such an automated chromatographic system could provide fast and accurate separation of multiple impurities, allow the process of high‐throughput samples, and reduce the time required for purification and recovery of minor impurities in drugs. [ABSTRACT FROM AUTHOR]

This study explores the fatigue behavior and fracture mechanisms of TC11 titanium alloy formed by laser metal deposition (LMD) and subjected to double annealing. The research focuses on how the alloy's unique microstructure, consisting of alternating equiaxed and columnar crystals, influences its fatigue performance. The microstructure's basket-like α' phase, made up of both plate-shaped and needle-like structures, leads to variations in crack growth behavior, as shown in the relationship between the crack growth rate and the stress intensity. An analysis of slip patterns reveals that equiaxed crystals undergo more frequent deformation, accelerating crack propagation compared to the more evenly distributed deformation in columnar crystals. These findings suggest a new approach for improving the fatigue resistance of 3D-printed titanium alloys by optimizing their microstructure. This study provides valuable insights for enhancing material toughness and extending the lifespan of titanium alloys in applications such as aerospace and biomedical engineering. [ABSTRACT FROM AUTHOR]

Proton exchange membrane water electrolyser (PEMWE) possesses great significance for the production of high purity of hydrogen. To expedite the anodic oxygen evolution reaction (OER) that involved multiple electron–proton‐coupled process, efficient and stable electrocatalysts are highly desired. Currently, noble‐metal Ir‐based materials are the benchmark anode due to its corrosion‐resistant property and favourable combination of activity/stability. However, the large‐scale deployment of PEMWE is usually constrained due to the use of the scarcest element iridium. In this review, we disclose the current research progress towards the non‐iridium‐based electrocatalysts for OER in acidic media, and then summarize some typical oxides that possesses good catalytic performance. Besides, we also present the unresolved problems and challenges in an attempt to enhance the activity/stability of these catalysts. [ABSTRACT FROM AUTHOR]

TiN‐based cermets with different Cr3C2 addition were prepared by conventional vacuum sintering. Effect of Cr3C2 on microstructure and properties of TiN‐based cermets were discussed. Owing to the formation of sound rims on TiN cores, ultrafine TiN‐based cermets with more uniform microstructure and finer grains were obtained with 1 wt% Cr3C2. When the added Cr3C2 content enhanced from 0 to 2 wt%, the transverse rupture strength (TRS) and fracture toughness increased firstly and then decreased, while the hardness increased monotonically. For the experimental conditions considered, the cermet with 1 wt% Cr3C2 addition had optimal combination of hardness (91HRA), fracture toughness (14.7 MPa m1/2) and TRS (2123 MPa). [ABSTRACT FROM AUTHOR]

Chlorogenic acid from the flower buds ofLonicera japonicaThunb was extracted by modified supercritical CO2with subsequent analysis by HPLC. Response surface methodology was utilized to optimize process parameters. The effects of pressure range from 100 to 300 bar, temperature range from 50°C to 80°C, and various concentration of ethanol used as co-solvent range from 20% to 60% (ethanol:water, v/v) on the yield of chlorogenic acid were studied in supercritical CO2extraction. The free radical-scavenging activity of the extracts was evaluated with 2,2-diphenyl-1-picrylhydrazyl assay. Two quadratic models were used to fit the effects of the variables on chlorogenic acid yield and the free radical-scavenging activity of the extracts, respectively. The optimized extraction conditions were 32% ethanol (v/v), temperature of 74°C, and pressure of 289 bar, producing a maximum yield of 5.51% with IE500.286 mg/mL inside the experimental domain. [ABSTRACT FROM PUBLISHER]

This work describes an optimized supercritical fluid extraction (SFE) process of osthole and imperatorin from the fruits ofCnidium monnieri(L.) Cusson. Response surface methodology (RSM) was employed to evaluate the effects of independent variables on the yields of osthole and imperatorin. The independent variables were extraction pressure (100 to 300 bar), temperature (50 to 70°C), and ethanol flow rate (0 to 0.4 mL/min). Results indicated that the data could be well fitted to two second-order polynomial models in the selected experimental domain. The effects of independent variables of pressure, temperature, ethanol rate flow, as well as the interactions between pressure and ethanol flow rate, and between temperature and ethanol flow rate on the extraction yield were significant for osthole or imperatorin extraction (p < 0.05). The models predicted that the optimized conditions were 243 bar, 64°C, ethanol flow rate of 0.28 mL/min, giving maximum yields of 1.29% and 0.53% for osthole and imperatorin, respectively, that were in good agreement with the experimental values. The extraction yields obtained with the optimized SFE and Soxhlet extraction were compared. [ABSTRACT FROM PUBLISHER]

ABSTRACT Protein hydrolysates were prepared from Bombay duck ( Harpodon nehereus) by the combination of commercially available papain and Flavourzyme (Novozymes, Copenhagen, Denmark) . The influences of hydrolysis time and enzymes substrate ratio on the degree of hydrolysis (DH) were investigated in detail. Hydrolysates were freeze-dried and the obtained powder was characterized with respect to yield, moisture, nitrogen recovery, amino acid composition and peptide molecular mass distribution. The mechanism of reducing bitterness of hydrolysates was also studied. A DH of up to 19.7% was obtained under the optimal hydrolysis conditions. The mass yield, nitrogen recovery and moisture of freeze-dried fish protein hydrolysates were 10.5 g/100 g wet weight of raw material, 87.5% and 4.2%, respectively. The molecular mass of hydrolysates determined by size-exclusion chromatography was between 219 and 5,245 Da. The oligopeptides were the main fraction of the hydrolysates. It was significant that L-leucine was removed from oligopeptides to reduce the bitterness of hydrolysates. PRACTICAL APPLICATION Bombay duck ( Harpodon nehereus) has high a nutrition value, with a protein content of up to 70% of dry mass. There is a great interest in utilizing the proteins of this fish efficiently on industrial scale. The hydrolysates of the fish protein were prepared by enzymatic hydrolysis and dry-freezing. The characteristics of hydrolysates were determined to predict their potential as a nutritious supplement in various food products. Low molecular peptides were the main composition of the hydrolysates, which possess health properties and promote food products supplemented by hydrolysates as healthy and nutritious. [ABSTRACT FROM AUTHOR]