ABSTRACT
Owing to its high sustainable production capacity, cellulose represents a valuable feedstock for the development of more sustainable alternatives to currently used fossil fuel-based materials. Chemical analysis of cellulose remains challenging, and analytical techniques have not advanced as fast as the development of the proposed materials science applications. Crystalline cellulosic materials are insoluble in most solvents, which restricts direct analytical techniques to lower-resolution solid-state spectroscopy, destructive indirect procedures or to 'old-school' derivatization protocols. While investigating their use for biomass valorization, tetralkylphosphonium ionic liquids (ILs) exhibited advantageous properties for direct solution-state nuclear magnetic resonance (NMR) analysis of crystalline cellulose. After screening and optimization, the IL tetra-n-butylphosphonium acetate [P4444][OAc], diluted with dimethyl sulfoxide-d6, was found to be the most promising partly deuterated solvent system for high-resolution solution-state NMR. The solvent system has been used for the measurement of both 1D and 2D experiments for a wide substrate scope, with excellent spectral quality and signal-to-noise, all with modest collection times. The procedure initially describes the scalable syntheses of an IL, in 24-72 h, of sufficient purity, yielding a stock electrolyte solution. The dissolution of cellulosic materials and preparation of NMR samples is presented, with pretreatment, concentration and dissolution time recommendations for different sample types. Also included is a set of recommended 1D and 2D NMR experiments with parameters optimized for an in-depth structural characterization of cellulosic materials. The time required for full characterization varies between a few hours and several days.
Subject(s)
Ionic Liquids , Ionic Liquids/chemistry , Solubility , Cellulose/chemistry , Solvents/chemistry , Magnetic Resonance Spectroscopy , Electrolytes/chemistryABSTRACT
Conventional wheat milling generates important volumes of wheat bran (WB), which is a concentrated source of polyphenols and insoluble fiber. In terms of health benefits and based on epidemiological and experimental evidence, these compounds contribute to reducing the risk of certain chronic pathologies. Protein concentration is the main quality factor conditioning wheat use in the agroindustry. When turning waste into feasible resources, it is essential to evaluate the variability of the raw material. The aim of this study was the evaluation of the impact of protein content in the valorization of WB based on its antioxidants, anti-inflammatory properties and glycemic index (GI). A significantly (p ≤ 0.05) lower content of phenolic compounds was found in the whole grain (WG) fractions, both free (FP) and bound (BP), as compared to the WB phenolic fractions, differences that ranged from 4- to 6-fold (538 to 561 mg GAE 100 g-1 in WG vs. 1027 to 1236 in WB mg GAE 100 g-1 in FP and 2245 to 2378 vs. 6344 to 7232 mg GAE 100 g-1 in BP). A significant (p ≤ 0.05) effect of the protein content on the resulting phenolic content and antioxidant capacity was observed, especially in WG, but also in WB, although in the latter a significant (p ≤ 0.05) negative correlation was observed, and increasing the protein content resulted in decreasing total phenolic content, antioxidants, and ferric-reducing capacities, probably due to their different types of proteins. The highest protein content in WB produced a significant (p ≤ 0.05) reduction in GI value, probably due to the role of protein structure in protecting starch from gelatinization, along with phytic acid, which may bind to proteins closely associated to starch and chelate calcium ions, required for α-amylase activity. A significant (p ≤ 0.05) effect of the protein content on the GI was also found, which may be explained by the structural effect of the proteins associated with starch, reducing the GI (21.64). The results obtained show the importance of segregation of WB in valorization strategies in order to increase the efficiency of the processes.
ABSTRACT
@#Objective: To present a unique case of blindness resulting from fungal rhinosinusitis involving multiple sinuses mimicking a malignant process in a pregnant patient. Methods: Design: Case Report Setting: Tertiary Government Training Hospital Patient: One Result: A 36-year-old pregnant woman developed unilateral blindness during her 20th week of gestation with a history of binocular diplopia, unilateral nasal obstruction and anosmia for 13 months during the pre-pregnancy period. Sphenoid sinus malignancy was suspected on imaging. The planned biopsy was intraoperatively shifted to endoscopic sinus surgery when clay-like materials were seen involving the left maxillary sinus and bilateral sphenoid and ethmoid sinuses. Histopathologic examination confirmed fungal growth. Postoperatively, nasal symptoms resolved but blindness of the left eye and blurring of vision of the right eye persisted. Conclusion: Fungal rhinosinusitis rarely occurs in multiple sinuses and is commonly misdiagnosed. It can afflict pregnant patients and mimic a malignant process. A high index of suspicion early on, especially in the presence of nasal congestion and diplopia may prevent potentially irreversible complications.
