Dickensskovbjerg0867

To obtain chitosan (CTS) with narrower molecular weight distribution, CTS with weight-average molecular weight (MW) of 197.30 kDa was first metal complexed and then degraded into five CTSs with MW of 107.90, 56.48, 10.40, 5.67 (CTS-4) and 3.66 kDa. Decrease of MW did not cause a significant change in chemical structure of the residue CTS, but the crystal structure was transformed significantly. The moisture retention increased firstly and then decreased as the MW of CTS decreased. EIDD-1931 mouse CTS-4 was superior to CTSs with other MW and propylene glycol in terms of the moisture retention. The lower water activity and increase of net isosteric heat were observed in CTS-4, which was due to the migration of immobilized water to a bound-state caused by mounting newly formed chain-end hydrophilic groups per unit weight. CTS-4 could effectively improve moisture retention, showing a potential to substitute commonly used humectant such as propylene glycol. Chitosan is a linear polysaccharide and non-toxic bioactive polymer with a wide variety of applications due to its functional properties such as ease of modification, and biodegradability. In this study, a green protocol for in situ fabrication of ultrafine Pd nanoparticles on chitosan-encapsulated Fe3O4/SiO2-NH2 nanoparticles, without the use of any toxic reducing agents, is described. The catalytic activity of Fe3O4/SiO2-NH2@CS/Pd nanocomposite was investigated through Suzuki-Miyaura coupling to synthesize biaryl derivatives, and reduction of 4-nitrophenol to 4-aminophenol. The core-shell nanoparticle modified with chitosan highly stabilizes the exterior Pd NPs. Leaching test was performed to assure heterogeneity of the catalyst. The magnetically retrievable catalyst was recycled up to eight times in both reactions without significant loss in its activity. Human milk oligosaccharides play an important role in promoting healthy growth of infants. Goat milk was one of the alternative sources for producing oligosaccharides. An in-depth understanding the composition and the quantity of oligosaccharides in goat milk was needed for its better utilization. In the present study, oligosaccharides were identified and quantified by using UPLC-MS/MS. The elution condition of UPLC was optimized leading to successful identification of 64 oligosaccharides in goat milk. Furthermore, the method to absolutely quantify 6 oligosaccharides in goat milk had been developed. The oligosaccharides in Guanzhong, local breed in China and Saanen goat milk, were compared by using this method. Five oligosaccharides were significantly different between two breeds. The amount of 6'-sialyllactose was 3.3 times higher in Guanzhong goat milk than that in Saanen goat milk. Guanzhong goat milk could be a potential good source for producing sialylated oligosaccharides, especially 6'-sialyllactose. This review focuses on cationic starches with a low degree of substitution ( less then 0.06) which are mainly used for production of paper-based products. After a brief introduction on starch in general, cationization pathways and importance of cationic starches in paper production, this review emphasizes on the analytical challenges from different perspectives. These include the different length scales of starches when in solution the macromolecular level, their assembly into nm aggregates and finally hydrocolloids with hundreds of nanometers of diameter. We give an overview on the current state of the art on the analysis of such challenging samples and aim at providing a guideline for obtaining and presenting reliable analytical data. Although the research on the cellulose allomorphs has been progressing for decades, many details especially in a nanoscale still require further exploration. In this article, the crystalline structure and morphology of cellulose III nanocrystals (CNC-III) are investigated after some typical modification routes. The results indicate that the crystalline structure of CNC-III is unsteady. After acetylation, hydrophobic cationization, polymer grafting and surface alkylation, CNC-III keep the original crystalline morphology but the crystallinity (62.8 %) decrease to 31.0 %, 42.5 %, 43.1 % and 43.8 %, respectively. However, after TEMPO-mediated oxidation and hydrophilic cationization, the crystalline structure of CNC-III transforms to the cellulose polymorph I and II, respectively. After modification, the dispersibility and thermal stability of CNC-III samples have been changed. Therefore, this systematic investigation is of great significance for understanding the effect of surface modification on the chemical and crystalline structure of CNC-III, which will provide a reference for future modifications and applications. The increased awareness about environment conservation and sustainable progress has encouraged the use of agricultural byproducts. Here, we investigated Borassus flabellifer leaf stalk residues as a sustainable precursor for nanofibrillated cellulose (NFC) production by sequential process. Alkali pretreatment and bleaching removed hemicellulose and lignin from B. flabellifer leaf stalk. Transmission electron microscopy images revealed the diameter and length of fibrillated cellulose nanostructure as 12-27 nm and 0.5-1 μm, respectively. NFC biocompatibility was analyzed in human mesenchymal stem cells (hMSCs) using cell viability assay, cellular and nuclear morphology analysis, mitochondrial membrane potential (MMP) assessment, and gene expression analysis. NFC showed no significant effect on hMSC viability at high concentration and failed to alter nuclear architecture and MMP. Biocompatibility assessment suggests that NFC is non-toxic and NFC-based films may enhance the adhesion and proliferation of hMSCs, highlighting its potential role as a suitable matrix for stem cell differentiation and biomedical applications. Ultrafine C-doped ZnO/carbon nanocomposites with different photocatalytic activities have been prepared using TEMPO-oxidized cellulose as a template but also as the source of carbon. The result is an enhancement of the photocatalytic activity ascribed to different phenomena a high mesoporosity beneficial to mass transport, a thin carbon layer onto ZnO increasing the charge transfer and hydrophobicity of ZnO, a narrowing of ZnO band gap and an increase of the zinc (VZn) and oxygen (Vo) vacancies effectively suppressing of the charge recombination. These are evidenced by photocatalytic test of photodegradation of methyl orange (MO) achieved to assess and compared the different photocatalysts. The highest rate constant value of photodegradation of MO is 0.0254 min-1, three times higher than that of ZnO prepared without templates (0.0087 min-1). The present results introduce a new vision of the use of template with multiple roles in the preparation of inorganic materials and specially photocatalysts. The present study aimed to investigate the protective effect of cultured Cordyceps sinensis polysaccharides (CSP) on cyclophosphamide (Cy)-induced intestinal mucosal immunosuppression and microbial dysbiosis in mice. Results showed that CSP stimulated cytokines secretion (IL-12, IFN-γ, IL-4, IL-13, IL-6, IL-17, IL-10, TGF-β3, TNF-α, IL-2, IL-21) and transcription factors production (T-bet, GATA-3, RORγt, Foxp3). TLRs (TLR-2, TLR-4, TLR-6) and NF-κB pathway key proteins (p-IκB-α, NF-κB p65) were also upregulated after CSP administration. Moreover, CSP recovered SCFAs levels which decreased by Cy treatment. Furthermore, 16S rRNA sequencing of fecal samples was performed. α-diversity and β-diversity analysis revealed CSP improved microbial community diversity and modulated the overall structure of gut microbiota. Taxonomic composition analysis found that CSP increased the abundance of probiotics (Lactobacillus, Bifidobacterium, Bacteroides) and decreased pathogenic bacteria (Clostridium, Flexispira). These findings suggested the potential of CSP as a prebiotics to reduce side effects of Cy on intestinal mucosal immunity and gut microbiota. This study aimed to develop an eco-friendly flexible surface-enhanced Raman scattering (SERS) substrate for in-situ detection of pesticides using biodegradable bacterial nanocellulose (BNC). Plasmonic silver nanoparticle- bacterial nanocellulose paper (AgNP-BNCP) composites were prepared by vacuum-assisted filtration. After loading AgNPs into BNC hydrogel, AgNPs were trapped firmly in the network of nanofibrous BNCP upon ambient drying process, resulting in 3D SERS hotspots within a few-micron depth on the substrate. The fabricated AgNP-BNCPs exhibited high SERS activity with good reproducibility and stability as demonstrated by the detection of 4-aminothiophenol and methomyl pesticide. Due to the optical transparency of BNCP, a direct and rapid detection of methomyl on fruit peels using AgNP-BNCPs can be achieved, demonstrating a simple and effective 'paste-and-read' SERS approach. These results demonstrate potential of AgNP-BNCP composites for user-friendly in-situ SERS analysis. Prenyltransferase NovQ immobilized carboxymethyl cellulose magnetic nanoparticles (NCMNs) were successfully synthesized via a valuable approach integrated from nanocomposite preparation, and applied for the production of vitamin K2 using menadione hydroquinol and dimethylallyl diphosphate (DMAPP) as substrates. To investigate the interaction between nanoparticles and NovQ, we characterized the nanocomposite, and revealed that carboxymethyl cellulose (CMC) and Fe3O4 formed a core-shell structure to absorb NovQ in the reaction systems, resulting from the high affinity of immobilized materials. Meanwhile, NCMNs with excellent pH and temperature tolerance, enhanced prenylated activity, and improved stability were found. Molecular docking analysis was also conducted to justify the contribution of multiple amino acids and effect of nanoparticles on catalytic properties of NovQ. Taken together, our study introduces a promising strategy to prepare magnetic nanoparticles and improve the performance of catalyst, which aims for opening new orientations for synthesis of magnetic nanoparticles used for prenyltransferase immobilization. The conformational states of chitosan macromolecules in solutions and their influence on the "grafting from" polymerization of 2-hydroxyethyl methacrylate and N-vinylpyrrolidone on the polysaccharide and the properties of their copolymers are studied. The conformational transition of macromolecules coil-rigid rod and rigid rod-globule in aqueous acidic solution was established by spectrophotometric method. The coil-rigid rod conformation transition depends on pH, it is sensitive to temperature and doesn't depend on the molecular weight of chitosan. The effective size of chitosan macromolecules for the rigid rod conformation was larger than for the coil conformation. The yield of the graft copolymer was significantly higher in case of where chitosan macromolecules were in the coil conformation (96 %) than in the rigid rod conformation (81 %). In the first case, the product of synthesis is a homogeneous solution, in the second case it is a colloidal solution. The copolymers were characterized by FTIR spectroscopy and gel-permeation chromatography. Adhesion loss of hydrocolloid wound dressings is ubiquitous clinical problem, which seriously reduces the therapeutic efficiency and patient experience. In order to address this problem, the clarification on adhesion loss mechanism and the development of effective alternatives of commercial hydrocolloid dressings are urgent and inevitable. Herein, adhesion loss mechanism of hydrocolloid dressings was investigated using sodium carboxymethyl cellulose (CMC)-filled hydrocolloid dressings exposing to physiological environment as model. The adhesion mechanism and contact angle tests were combined to obtain surface energy of dressings. The results indicated that the dissolution, swelling and exudation of CMC occurred successively (concentration reached 1.607 g/L after 10 h). The effused CMC led to the dramatic increase in surface energy (from 14.5-80.7 mN/m) and adhesion loss appeared. This work explored the origin of adhesion loss of hydrocolloid wound dressings and might promote the designing of hydrocolloid dressings with both excellent humidity control and sustained self-adhesiveness.