Template-Free Synthesis and Multifunctional Application of Foam HKUST-1.

Hierarchically porous metal-organic frameworks (HP-MOFs) have attracted a lot of attention in recent years because their hierarchical pores have critical importance in strengthening their performance, including guest diffusion kinetics, catalytic activity, and selectivity, especially with reference to large molecules. However, the preparation method for simple, controllable, and stable HP-MOFs at a micro-/meso-/macroscopic scale is still lacking. Herein, we showed several forms of HKUST-1 (HKUST = Hong Kong University of Science and Technology) by simply changing the copper source and solvent type, including original micron HKUST-1 (O-HKUST-1), half-foam HKUST-1 (HF-HKUST-1), and fully foam HKUST-1 (F-HKUST-1). Compared to O-HKUST-1, HF-HKUST-1 and F-HKUST-1 possessed an apparent hierarchically porous structure due to the high fusion of HKUST-1 nanocrystals. Especially in F-HKUST-1, all of the HKUST-1 nanocrystals were tightly integrated into each other, which formed a holistic hollow foam structure. Hence, F-HKUST-1 exhibited the highest adsorption capacity toward large molecules, including proteases, phosphotungstic acid, and organic dyes. Meanwhile, F-HKUST-1 presented the highest photocatalytic degradation capability for rhodamine B. Furthermore, F-HKUST-1, loaded with phosphotungstic acid (F-HKUST-1@PTA), which was used as a catalyst, indicated a catalytic capacity comparable to that of a homogeneous catalyst (pure phosphotungstic acid).

A new method for mutation inducing in rice by using DC electrophoresis bath and its mutagenic effects.

Mutation breeding is a significant means of increasing breeding efficiency and accelerating breeding process. In present study, we explored a new method for mutations inducing in rice (Oryza sativa L.) by using direct current electrophoresis bath (DCEB). The results showed that 20 mM NaCl solution is the optimal buffer, and the mortality of rice seeds followed an upward trend with increasing voltage and processing time of DCEB. By exploring the mutagenic effects of γ-irradiation and DCEB on seed vigor and physiological damages, we found that the physiological damages induced by DCEB on seed vigor were significant compared with that by γ-irradiation. We screened two mutants with low filled grain percentage and one mutant with abnormal hull from the M2 generations. These three mutants were confirmed to be authentic mutants based on 48 SSR markers followed by the protocol NY/T 1433-2014. Whole-genome resequencing detected a total of 503 and 537 polymorphisms in the two mutants, respectively, and the DCEB mutagenesis induced mainly InDel variants, while the exon region of mutant genes occupied a large proportion, especially the SNP variants, which occupied about 20% of the mutation sites in the exon region.

Template Method for Synthesizing Hierarchically Porous MIL-101(Cr) for Efficient Removal of Large Molecular Dye.

As one of the most important prototypical chromium-based MOFs, MIL-101(Cr) is well-studied and widely employed in various scientific fields. However, due to its small capture window sizes and curved internal apertures, its application in large molecular removal is quite limited, and given its high stability and high synthetic temperature (>200 °C), it is difficult to achieve hierarchically porous MIL-101(Cr). In our study, hierarchically porous MIL-101(Cr) involving a high macro-/meso-/micropores ratio was designed and synthesized using acetic acid as an additive and silicon dioxide (SiO2) nanoparticles as a template. The optimal hierarchically porous MIL-101(Cr) (A-4) possessed a high specific surface area (2693 m2 g−1) and an abundant macro-/mesoporous structure with the addition of SiO2 of 200 mg. Compared with the control sample (A-0) with a less macro-/mesoporous structure, A-4 showed good adsorption properties for both coomassie brilliant blue R-250 (CBB, 82.1 mg g−1) and methylene blue (MB, 34.3 mg g−1) dyes, which were 1.36 times and 9.37 times higher than those of A-0. Moreover, A-4 also had good recyclability, and the removal rate of CBB was still higher than 85% after five cycles of adsorption.

Advances in Metal-Organic Frameworks MIL-101(Cr).

MIL-101(Cr) is one of the most well-studied chromium-based metal-organic frameworks, which consists of metal chromium ion and terephthalic acid ligand. It has an ultra-high specific surface area, large pore size, good thermal/chemical/water stability, and contains unsaturated Lewis acid sites in its structure. Due to the physicochemical properties and structural characteristics, MIL-101(Cr) has a wide range of applications in aqueous phase adsorption, gas storage and separation, and catalysis. In this review, the latest synthesis of MIL-101(Cr) and its research progress in adsorption and catalysis are reviewed.

Nanofused Hierarchically Porous MIL-101(Cr) for Enhanced Methyl Orange Removal and Improved Catalytic Activity.

Hierarchically porous MIL-101(Cr) (H-MIL-101(Cr)) with meso/macro-pores was directly prepared via nanofusion progress by using butyric acid as a modulating agent. In the methyl orange (MO) adsorption experiments, H-MIL-101(Cr) showed a high adsorption capability of 369.8 mg g-1, which was 1.52-fold greater than that of pristine MIL-101(Cr) (P-MIL-101(Cr)). While in the oxidation reaction of indene and 1-dodecene tests, H-MIL-101(Cr) presented much higher catalytic efficiency, with turnover frequency (TOF) values of 0.7242 mmol g-1 min-1 and 0.1492 mmol g-1 min-1, respectively, which were 28% and 34% greater than that in the case of P-MIL-101(Cr). Thus, compared with P-MIL-101(Cr), H-MIL-101(Cr) exhibited better removal efficiency and higher levels of activity in the oxidation reactions of indene and 1-dodecene. The unique structure of H-MIL-101(Cr) also contributed to its superior performance in these processes.

Ginkgo Seed Proteins: Characteristics, Functional Properties and Bioactivities.

Ginkgo biloba L. is an ancient plant relic, which is known as a "living fossil", and is widely cultivated in China. This plant with medical potential and health benefits has drawn the attention of researchers. Ginkgo seeds are rich in protein. Ginkgo seed proteins (GSPs) have good functional properties over many other seed proteins, which have the potential to be utilized as food ingredients. Moreover, GSP contains no restricted amino acids and is easy to be separated. Several GSP isolate with various bioactivities, such as antimicrobial and antioxidative activities, have been purified and evaluated for their bioactive potential. In this review, the separation methods and bioactivities of GSP were summarized, physicochemical characteristics and functional properties were comprehensively reviewed and compared with other seed proteins. Some food applications of GSP were also briefly introduced. Besides, some suggestions and prospects were discussed in this review.

Efficient removal of ginkgotoxin from Ginkgo biloba seed powder by combining endogenous enzymatic hydrolysis with resin adsorption.

BACKGROUND: Ginkgotoxin including 4'-O-methylpyridoxine (MPN) and MPN-5'-glucoside (MPNG) is responsible for Ginkgo seed food poisoning. The purpose of the work reported was to prepare detoxified Ginkgo seed powder and at the same time to retain the nutritional and functional components of Ginkgo seed powder to the maximum extent. RESULTS: Resin adsorption technology was firstly employed to remove ginkgotoxin from water extract of Ginkgo seed powder. Under optimal conditions, the adsorption efficiency of the optimal resin for MPN could reach 100%, and that for MPNG could only reach 85.4 ± 0.93%. Resin adsorption alone could not effectively remove MPN and MPNG simultaneously. Endogenous enzymatic hydrolysis was next attempted to transform MPNG to MPN. MPNG could be completely hydrolyzed to MPN by endogenous enzyme(s) at 40 °C and pH 5.0 in 180 min. Ginkgotoxin only in the form of MPN in the enzymatic hydrolysate was then adsorbed with resin and the conditions were statistically optimized. The adsorption efficiency of MPN reached 98.89 ± 0.99% under the optimized conditions. CONCLUSIONS: Removal of ginkgotoxin by combining endogenous enzymatic hydrolysis with resin adsorption could preserve the main nutritional and functional components of Ginkgo seed powder to the most extent, and did not change its main characteristics. The ginkgotoxin removal method developed in this work is a relatively simple and efficient approach. © 2020 Society of Chemical Industry.

Submerged fermentation of Ginkgo biloba seed powder using Eurotium cristatum for the development of ginkgo seeds fermented products.

BACKGROUND: Ginkgo biloba seeds are well known for the significant curative effects on relieving cough and asthma. However, the development of products from ginkgo seeds still falls behind at present, resulting in a great waste of ginkgo seeds' resource. In this work, submerged fermentation of ginkgo seed powder using Eurotium cristatum was studied to investigate its feasibility as a new processing method. RESULTS: To promote the growth of E. cristatum, the optimum fermentation medium was 80.0 g L-1 of ginkgo seed powder with addition of 5.0 g L-1 calcium chloride (CaCl2 ), 4.0 g L-1 magnesium sulfate (MgSO4 ), 1.25 g L-1 zinc sulfate (ZnSO4 ) and 0.65 g L-1 iron(II) sulfate (FeSO4 ). The optimum fermentation conditions were pH 5.8 ± 0.1, inoculum size 5.1 × 106 CFU mL-1 , liquid medium volume 100 mL in 250-mL Erlenmeyer flask and fermentation 4 days. Through fermentation, the production of lovastatin in fermentation broth could reach up to 32.97 ± 0.17 µg mL-1 and the total antioxidant capacity was improved by more than two-fold. In addition, 40.15% of the ginkgotoxin in ginkgo seed powder was degraded while the entire degradation of ginkgolic acids was obtained. Moreover, fermented ginkgo seed powder suspension presented pleasant fragrances, and the activities of amylase and protease were enhanced to 11.30 ± 0.10 U mL-1 and 23.01 ± 0.20 U mL-1 , respectively. CONCLUSIONS: Submerged fermentation using E. cristatum could significantly enhance the functional value and safety of ginkgo seed powder, and had great potential to become a novel processing method for the development of ginkgo seeds fermented products. © 2020 Society of Chemical Industry.

Comparing the role of annealing on the transport properties of polymorphous AgBiSe2 and monophase AgSbSe2.

AgBiSe2 and AgSbSe2, two typical examples of Te-free I-V-VI2 chalcogenides, are drawing much attention due to their promising thermoelectric performance. Both compounds were synthesized via melting and consolidated by spark plasma sintering. The role of annealing on the transport properties of polymorphous AgBiSe2 and monophase AgSbSe2 was studied. Annealing has a greater impact on AgBiSe2 than AgSbSe2, which is ascribed to the temperature dependent phase transition of AgBiSe2. Unannealed AgBiSe2 shows p-n switching, but annealed AgBiSe2 exhibits n-type semiconducting behavior over the whole measurement temperature range. By performing high-temperature Hall measurements, we attribute this intriguing variation to the change in the amount of Ag vacancies and mid-temperature rhombohedral phase after annealing. Both AgBiSe2 and AgSbSe2 exhibit low thermal conductivity values, which are ∼0.40-0.50 W m-1 K-1 for AgSbSe2 and ∼0.45-0.70 W m-1 K-1 for AgBiSe2, respectively. The maximum ZT value of AgBiSe2 is enhanced from 0.18 to 0.21 after annealing. Pristine AgSbSe2 presents a ZT value as high as 0.60 at 623 K, although slight deterioration emerges after annealing.