Polydopamine Doping and Pyrolysis of Cellulose Nanofiber Paper for Fabrication of Three-Dimensional Nanocarbon with Improved Yield and Capacitive Performances

Biomass-derived three-dimensional (3D) porous nanocarbons have attracted much attention due to their high surface area, permeability, electrical conductivity, and renewability, which are beneficial for various electronic applications, including energy storage. Cellulose, the most abundant and renewable carbohydrate polymer on earth, is a promising precursor to fabricate 3D porous nanocarbons by pyrolysis. However, the pyrolysis of cellulosic materials inevitably causes drastic carbon loss and volume shrinkage. Thus, polydopamine doping prior to the pyrolysis of cellulose nanofiber paper is proposed to fabricate the 3D porous nanocarbons with improved yield and volume retention. Our results show that a small amount of polydopamine (4.3 wt%) improves carbon yield and volume retention after pyrolysis at 700 °C from 16.8 to 26.4% and 15.0 to 19.6%, respectively. The pyrolyzed polydopamine-doped cellulose nanofiber paper has a larger specific surface area and electrical conductivity than cellulose nanofiber paper that without polydopamine. Owing to these features, it also affords a good specific capacitance up to 200 F g−1 as a supercapacitor electrode, which is higher than the recently reported cellulose-derived nanocarbons. This method provides a pathway for the effective fabrication of high-performance cellulose-derived 3D porous nanocarbons.

ANALISIS HASIL FRAKSINASI PROTEASE DAN LIPASE YANG BERASAL DARI SALURAN PENCERNAAN UDANG VANAME (Litopenaeus vannamei)

Analysis of Protease and Lipase Fractionation Originated from the Digestive Tract of Vannamei Shrimp (Litopenaeus vannamei) Vannamei shrimp is a fishery commodity with a high consumption value, so it has an impact of high shrimp waste in the form of head and skin. The digestive tract connected to the head of the vaname shrimp (Litopenaeus vannamei) contains digestive enzymes, including proteases and lipases. This study aims to obtain the protein fraction that has the highest protease and lipase activity. The separation method used was centrifugation followed by precipitation using ammonium sulfate salt and dialysis. The dialysate was purified by gel filtration chromatography at a volume retention of 10 drops per tube. The proteolytic and lipolytic enzyme activity of the fraction was measured using a spectrophotometer. The results showed that fraction 102 had the highest protease activity value of 96.3924 U / mL, while fraction 100 had the highest lipase activity of 531.07 U / mL. This study showed that in the digestive tract of vaname shrimp, protease and lipase activity increased with the level of purity. Keywords: digestive enzymes, gel filtration chromatography, lipase, protease, vannamei shrimp ABSTRAK Udang vaname merupakan komoditi perikanan dengan nilai konsumsi yang tinggi, sehingga berdampak pula dengan tingginya limbah udang yang berupa kepala dan kulit. Saluran pencernaan yang terhubung dengan kepala udang vaname (Litopenaeus vannamei) mengandung enzim pencernaan, diantaranya protease dan lipase. Penelitian ini bertujuan untuk mendapatkan fraksi protein yang memiliki aktivitas protease dan lipase tertinggi. Metode pemisahan yang dilakukan adalah sentrifugasi dilanjutkan dengan pengendapan menggunakan garam ammonium sulfat dan dialisis. Dialisat dimurnikan dengan kromatografi filtrasi gel pada retensi volume sebanyak 10 tetes tiap tabung. Aktivitas enzim proteolitik dan lipolitik fraksi diukur menggunakan spektrofotometer. Hasil menunjukkan bahwa fraksi 102 memiliki nilai aktivitas protease tertinggi sebesar 96,3924 U mL–1, sedangkan fraksi 100 memiliki aktivitas lipase tertinggi sebesar 531,07 U mL–1. Penelitian ini menunjukkan bahwa pada saluran pencernaan udang vaname terdapat aktivitas protease dan lipase yang meningkat seiring dengan tingkat kemurniannya.

Abstract P131: Jak2 Expression In Cd11c+ Myeloid Cells Plays A Role In Salt-sensitive Hypertension Through An Enac-dependent Mechanism.

Hypertension is a major risk factor for development of cardiovascular disease. Excess dietary salt contributes to inflammation and the genesis of hypertension. We recently found that gamma and alpha subunits of the epithelial sodium channel (ENaCαγ) on dendritic cells mediate NADPH oxidase-dependent formation of immunogenic isolevuglandin (IsoLG)-protein adducts leading to inflammation and salt-sensitive hypertension. We hypothesized that Jak2 expression, specifically in CD11c + myeloid cells, regulates expression of ENaCγ and promotes salt-sensitive hypertension. Our results indicate that deletion of Jak2 in CD11c + myeloid cells reduced the salt-induced expression of ENaCγ in CD11c+ cells. Moreover, mice lacking Jak2 in CD11c+ cells developed a blunted hypertensive response (123.8±4.7) during the high salt feeding phase of the N-Nitro-L-arginine methyl ester hydrochloride (L- NAME)/high salt model of salt-sensitive hypertension compared to their wildtype littermate controls (140.5±6.5). These mice also exhibited less infiltration of monocyte/macrophages in their kidneys and less volume retention (69.55±5.8) in response to high salt-feeding when compared to the wildtype litter mate controls (57.89±9.5). These results indicate that Jak2 expression in CD11c + myeloid cells plays a role in salt- sensitive hypertension through an ENaC-dependent mechanism.