In this paper, nano-Ti-2Fe-0.1B alloys with different grain sizes were processed by high pressure torsion (HPT) deformation. The study examined the microstructural evolution of the Ti-2Fe-0.1B alloy during HPT and evaluated its mechanical properties through microhardness and tensile tests. The results of the microstructural observations revealed that the grain size of the Ti-2Fe-0.1B alloy progressively decreased from 3.14 mu m in the asannealed state to approximately 20 nm after 10 turns. In the initial state, the alloy consists of alpha-phase and beta-phases, with a volume ratio of approximately 5:1. During the HPT process, transformations of alpha-phase and beta-phase to o-phase were observed. The primary reason for this is that the shear forces applied during the HPT process facilitated the phase transformation of the alpha-phase. Additionally, the presence of Fe element in the alloy altered the lattice compatibility between the grains of beta-phase and o-phase, thereby promoting the phase transformation of the beta-phase, with the accumulated turns of HPT process, the fraction of o-phase increased in the beginning gradually, then decreased, which reached to the maximum 80.8% in the 5 turns. This is higher than that of pure titanium and Ti-Fe alloys under the same conditions, because the proportion of the o-phase increases with the increase in Fe content. Studies of mechanical properties demonstrated that HPT can substantially enhance the hardness of Ti-2Fe-0.1B alloys to as high as 483 HV, and the tensile strength of the Ti-2Fe0.1B alloy was observed to increase from 725 MPa to 1568 MPa after 5 turns, which is much higher than Ti-6Al-4V subjected to the identical processing conditions. It can be ascribed to the exist of mass o-phase as well as finer grain size in nanocrystalline Ti-2Fe-0.1B alloy.

Antarctic krill oil (AKO) possesses potent bioactivities but has limited applications in the food industry due to its poor stability, strong off-flavor, and low bioavailability of contained astaxanthin. In this study, Antarctic krill protein isolate (AKPI) was separated from processing by-product of krill and utilized as a novel wall material via complexing it with gum Arabic (GA) to improve the limitations of AKO. The strong complex coacervation reaction between AKPI and GA was occurred at the pH of 3.8 and the ratioAKPI-to-GA of 3:1, while electrostatic interaction and hydrogen-bond interaction were determined to be the main driving forces of such reaction. The ratiowall-to-core was confirmed as 1:0.75 after comprehensively assessing the effect of AKO content on the various properties of AKPI-GA coacervated microcapsules, while the wall material concentration and pH were optimized at 1 % and 3.8, respectively. The obtained solid AKO microcapsules exhibited the encapsulation efficiency of 80.22 %. AKPI-GA coacervated microcapsules extremely masked the odor of AKO and achieved the controlled-release of AKO in the gastrointestinal tract. Meanwhile, the encapsulated AKO displayed higher astaxanthin retention and oxidative stability compared with non-encapsulated AKO during storage.

Quercetin-3,4'-O-diglucoside (Q3,4'G), among the major dietary flavonoids, is superior to quercetin aglycone or quercetin monoglucoside in solubility. However, its low content in nature makes it hard to be prepared in large quantities by traditional extraction methods. In the present study, the F378S mutant of UGT78D2 (78D2_F378S) derived from Arabidopsis thaliana with improved regioselectivity and the V371A mutant of UGT73G1 (73G1_V371A) derived from Allium cepa were adopted to realize a two-step continuous glycosylation of quercetin to produce Q3,4'G. The mutation S31D was introduced to the sucrose synthase from Micractinium conductrix with enhanced activity, which was responsible for regenerating UDP-glucose by coupling with 78D2_F378S and 73G1_V371A. Using the aforementioned enzymes, prepared from the three-enzyme co-expression strain, 4.4 ± 0.03 g/L (7.0 ± 0.05 mM, yield 21.2%) Q3,4'G was produced from 10 g/L quercetin after reaction for 24 h at 45 °C.

Compared with bimodal microstructure, the low-cycle fatigue (LCF) behavior and cyclic deformation mechanism of a near beta Ti-3Al-5Mo-4Cr-2Zr-1Fe (Ti-35421) alloy with single beta were systematically investigated. Lower strength, but higher ductility and longer LCF life were found for Single beta. The nanoscale alpha '' martensite was detected in Single beta by selected area electron diffraction pattern. Besides, slips and strain induced martensitic transformation played the major deformation mechanisms in Single beta. Moreover, the existence of alpha '' contributed to the limit of microcracks nucleation in Single beta, which resulted in a better fatigue life.

Sucrose synthase (SuSy, EC 2.4.1.13) is a unique glycosyltransferase (GT) for developing cost-effective glycosylation processes. Up to now, some SuSys derived from plants and bacteria have been used to recycle uridine 5'-diphosphate glucose in the reactions catalyzed by Leloir GTs. In this study, after sequence mining and experimental verification, a SuSy from Micractinium conductrix (McSuSy), a single-cell green alga, was overexpressed in Escherichia coli, and its enzymatic properties were characterized. In the direction of sucrose cleavage, the specific activity of the recombinant McSuSy is 9.39 U/mg at 37°C and pH 7.0, and the optimum temperature and pH were 60°C and pH 7.0, respectively. Its nucleotide preference for uridine 5'-diphosphate (UDP) was similar to plant SuSys, and the enzyme activity remained relatively high when the DMSO concentration below 25%. The mutation of the predicted N-terminal phosphorylation site (S31D) significantly stimulated the activity of McSuSy. When the mutant S31D of McSuSy was applied by coupling the engineered Stevia glycosyltransferase UGT76G1 in a one-pot two-enzyme reaction at 10% DMSO, 50 g/L rebaudioside E was transformed into 51.06 g/L rebaudioside M in 57 h by means of batch feeding, with a yield of 76.48%. This work may reveal the lower eukaryotes as a promising resource for SuSys of industrial interest.