RESUMO
This study revealed the influence of phosphorylation-dimethylammonium chloride acyloxylation (PDACA) on the desizability, film properties, paste stability, and adhesion of biological starch macromolecules. A new starch-based sizing agent, phosphorylated-dimethylammonium chloride acyloxylated starch (PDACAS), was synthesized with degrees of substitution (DS) ranging from 0.033 to 0.065. Compared to control phosphorylated-quaternized starch (PQS, 87.4 %), the desizing efficiency of cotton yarns sized with PDACAS was ~94 %, exceeding the industrial minimum requirement of 90 %. The PDACAS film tensile properties were as follows: elongation at break of 3.31 %-3.78 %, bending endurance of 1131-1537 cycles, and tensile strength of 35.83-28.31 MPa, compared with those of acid-thinned starch (ATS) film (2.74 %, 957 cycles, and 38.12 MPa). The PDACAS had paste stability of ~92 %, compared with 83.3 % for ATS. The bonding forces (an indicator of adhesion to fibers) ranged from 107.1 N to 125.3 N for cotton roving, and 128.3 N to 148.7 N for polyester/cotton roving, which were significantly better than those of ATS (95 N for cotton and 117.9 N for polyester/cotton roving). Overall, PDACA treatment effectively avoided the adverse effect of high DS quaternization on the desizability of PQS and imparted good film properties, paste stability, and adhesion to starch.
Assuntos
Dimetilaminas , Fosfatos , Amido , Têxteis , Poliésteres , Resistência à TraçãoRESUMO
Miscanthus floridulus fibers obtained from the seed floss of M. floridulus (a perinneal plant of Gramineae native to Africa and Asia and widely distributed in tropical and subtropical regions) have potential application value in textile and other fields. At present, the biological characteristics and ecological benefits of Miscanthus floridus have been extensively studied by researchers, but there have been no literature on M. floridus fibers. In order to make reasonable use of M. floridus fibers, their morphological structure, physical properties, chemical composition, thermal insulation properties, and surface absorption properties were explored in detail in this study. The results showed that the M. floridus fiber is fine and short and has a hollow structure with a density of 0.67 g cm-3. Chemical analyses revealed that the main constituents of the fiber are cellulose (66.98%), hemicelluloses (13.86%), lignin (6.97%), pectin (1.99%), and wax (4.38%). The fill power and warmth retention performance of the fiber are similar to those of wool. In particular, the M. floridus fiber surface has hydrophobic and lipophilic properties with a static contact angle of 123.7° for water droplets in equilibrium. Therefore, the M. floridus fiber has a promising application prospect in bulk textile thermal insulation and oil-water separation fields.
RESUMO
Cholesterol overloading-induced damages on hepatocytes cause liver dysfunctions, which further damages cholesterol metabolism and results in visceral fat accumulation in patients with type 2 diabetes mellitus (T2DM). The sodium-glucose cotransporter 2 (SGLT2) inhibitor Dapagliflozin has been reported to regulate cholesterol levels in T2DM patients, but the underlying mechanisms have not been studied. In the present study, we initially established in vivo T2DM mice models, and our results showed that both free cholesterol (FC) and cholesteryl ester (CE) were accumulated, while the pro-proliferation associated genes were downregulated in T2DM mice liver tissues, which were reversed by Dapagliflozin co-treatment. Similarly, the mice primary hepatocytes were loaded with cholesterol to establish in vitro models, and we expectedly found that Dapagliflozin attenuated cholesterol-overloading induced cytotoxicity and cellular senescence in the hepatocytes. Then, we noticed that oxidative damages occurred in T2DM mice liver tissues and cholesterol treated hepatocytes, which could be suppressed by Dapagliflozin. Also, elimination of Reactive Oxygen Species (ROS) by N-acetyl-L-cysteine (NAC) recovered cellular functions of hepatocytes in vitro and in vivo. Furthermore, the potential underlying mechanisms were uncovered, and our data suggested that Dapagliflozin activated the anti-oxidant Nrf2/HO-1 pathway in mice hepatocytes, and silencing of Nrf2 abrogated the protective effects of Dapagliflozin on cholesterol-overloaded hepatocytes. Collectively, we concluded that Dapagliflozin recovered cholesterol metabolism functions in T2DM mice liver via activating the anti-oxidant Nrf2/HO-1 pathway, and our data supported that Dapagliflozin was a potential therapeutic drug to eliminate cholesterol-induced cytotoxicity during T2DM pathogenesis.