Search

Objective: This study aimed to explore the quality features of basal tea of noval-jasmine tea. Methods: Taking three kinds of basal tea（Fujian Xianghao, Yunnan Maojian, Sichuan Xiangming）of noval-jasmine tea beverage scenting tea dhool from Fujian, Yunnan and Sichuan as the research objects, the quality of the base tea including main biochemical components, taste, aroma were analyzed by electronic tongue, solid phase microextraction combined with gas chromatography-mass spectrometry (GC-MS), sensory evaluation and chemical analysis. Results: Water extracts of three kinds of basal tea was 49.40%~51.40%, tea polyphenols was 18.00%~23.20%, caffeine was 3.20%~4.30%, free amino acid was 3.32%~3.50%. The main biochemical components and 16 kinds of amino acids of Yunnan Maojian were higher than the other two. The response values of acerbity, salty, richness of Yannan Maojian were the maximum, but the response value of sweet was the minimum, and tea soup was heavy and strong. The response values of acerbity and salty of Fujian Xianghao were the minimum, but the water extracts were high, and tea soup was thick and mellow. The contents of esters were the maximum, followed by alcohols and olefins. The order of aroma quality from high to low was Fujian Xianghao, Yunnan Maojian and Sichuan Xiangming，which were all middle degree by aroma evaluation. Conclusion: The inclusion of the three kinds of basal tea of noval-jasmine tea beverage were abundant, but the aroma quality needed improvement.

The corona virus disease 2019 (COVID-19) pandemic has created a global health and economic crisis. Our studies uncovered that in addition to respiratory symptoms, liver damage is also common in COVID-19 patients; however, the cause of liver damage has not been fully elucidated. In this article, we summarize the clinical manifestations and pathological features of COVID-19 reported in published relevant studies and delineate the etiology and pathogenesis of COVID-19-related liver injury. We speculate that cold stimulation may be associated with COVID-19-related liver injury, which should be considered in clinical decision-making and treatment of COVID-19 in cold regions.

Polymeric vesicles with tertiary amine and epoxy functional groups were fabricated via the reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization of 2-(diisopropylamino) ethyl methacrylate (DIPEMA) and glycidyl methacrylate (GlyMA) in an ethanol-water mixture by using poly (ethylene oxide)-4-(4-Cyanopentanoic acid) dithiobenzoate (mPEG45-CPADB) as the macro-chain-transfer agent (macro-CTA). Biocompatible polymer mPEG45 with molecular weight of 2000 and 4-(4-Cyanopentanoic acid) dithiobenzoate (CPADB) were used for the macro-CTA synthesizing via the esterification reaction. Investigation of the degree of polymerization (DP) of the hydrophobic block P(DIPEMA-co-GlyMA) and the solid content indicated that both have significant effect on the particle morphology and particle diameter. 1H NMR and FTIR analysis indicated the existing of tertiary amine and epoxy functional groups on the produced vesicles.

PP/FG composite materials were prepared by compressing moulding under high temperature through high-speed mixer, mixing mill and vulcanization machine taking PP as the matrix resin, FG as the thermal conductive filler, and NDZ-201 as the coupling agent. Effects of PP proportion, FG content and particle size on the thermal conductivity and mechanical properties of composite materials were studied. Results showed that PP proportion has little effect on the thermal conductivity of PP/FG composite materials, but it greatly affects the mechanical properties of the composite materials. Overall, the quality ratio of PP230 to K-4038 at 50:50 is more suitable. With the increasing of FG content, the thermal conductivity increases, and a significant critical value appears when the FG content is 50 wt%; The strength of the composite material first decreases and then increases, with an increase in modulus and a decrease in strain. As the FG particle size increases, the thermal conductivity of the composite material increases and the mechanical properties decrease.

A polyethylenimine adjuvant modified by mannose, which may be used in the study of vaccine adjuvant, was prepared in this paper. Its structure was characterized by infrared spectroscopy and its micromorphology was observed by transmission electron microscopy. A series of mannose-modified polyvinylimine were prepared according to the molar ratio of primary amine groups between mannose and polyvinylimine, and their storage stability was observed at 4°C. In addition, the cytotoxicity of modified and unmodified polyethylenimine was also tested, and the results showed that the modified polyethylenimine was less toxic than unmodified polyethylenimine.

Poly (lactic-co-glycolic acid) (PLGA) is a kind of medical polymer material with good biodegradability and histocompatibility, which is widely used in postoperative anti-adhesion materials. In this paper, PLGA microfiber membrane was successfully prepared with poly(lactic-co-glycolic acid) as the main material by electrospinning technology. The surface morphology, wettability, dimensional stability and mechanical properties of PLGA microfiber films were characterized by scanning electron microscopy (SEM) and tensile testing machine. The results show that the average diameter of the prepared PLGA fiber is 2.218~2.313 μm, the elongation at break of the fiber film is up to 193%, and the dimensional stability and wettability of the fiber film are maintained at 37°C. The degradation cycle is 2~3 months.

Polypropylene (PP) composite materials were prepared through two molding methods of injection and compression molding, taking PP, FG as the matrix and thermal conductive filler. The effects of molding methods and FG content on the thermal conductivity of composite materials were studied, and the SEM, XRD, and thermal expansion properties of the materials were further analyzed. Results showed that thermal conductivity of the composite material increases with increasing of the FG content. When the FG content was 75 wt%, the average thermal conductivity of the composite materials prepared by injection molding and compression molding is 9.88 W·m-1·K-1 and 6.03 W·m-1·K-1, respectively. The axial thermal conductivity is 16.6 W·m-1·K-1 and 1.35 W·m-1·K-1, and the radial thermal conductivity is 5.88 W·m-1·K-1 and 26.9 W·m-1·K-1, respectively. In composite materials formed by injection molding, the flaky FG is mainly oriented vertically, while in compression molding, the flaky FG is mainly oriented horizontally.

2-(diisopropylamino) ethyl methacrylate (DIPEMA) and glycidyl methacrylate (GlyMA) were used for the investigation of the redox-initiated reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization, by using poly (ethylene oxide)-4-(4-Cyanopentanoic acid) dithiobenzoate (mPEG-CPADB) as the macro-chain-transfer agent (macro-CTA). The particle growth process study indicated that the particles changed from spheres to worms, and then to vesicles during the polymerization process. The degree of polymerization (DP) of the hydrophobic block P(DIPEMA-co-GlyMA) affected the particle morphology, particle diameter and molecular weight significantly. Pure polymeric vesicles could be obtained when DP was equal to or higher than 60, and with increasing of the DP of the hydrophobic block, the diameter and the molecular weight of the particles both increased.