Allenhald7095

Considerable attention has been focused on the application of natural cellulosic materials due to the cost-effectiveness, renewability, and biodegradability of cellulose. However, gaps between cellulose-based and petroleum-based materials still exist. In this study, a green, environmental modification method for cellulose by enzyme-initiated reversible addition fragmentation chain transfer (RAFT) graft polymerization was reported. First, the grafting of acryloyl chloride (AC) provided reaction sites on cellulosic fiber surfaces, followed by the enzymatic RAFT graft polymerization of acrylamide (AM). The grafting of well-controlled polyacrylamide (PAM) chains on the cellulosic material surface was verified by Fourier transform infrared spectrometer (FTIR), X-ray photoelectron spectroscopy (XPS), and the controlled grafting ratio was also estimated. The transition of wetting behaviors after the modification of AC and PAM also provided evidence for successful grafting on cellulosic materials. In addition, this method can be well applied for the preparation of various functional cellulosic materials.Nano-chitosan (NCH), nano-cellulose (NCL) and cellulose derivative are biodegradable biopolymer. Nano-chitosan or nano-cellulose at different concentrations (0.1, 0.5 and 1%) incorporated in carboxymethyl cellulose (CMC) film solution using casting methods. Both CMC/NCH and NCL decreased physical properties (water solubility, moisture content and moisture absorption) especially in concentration of 1%. However, these properties in CMC/NCH were significantly (p less then 0.05) lower than CMC/NCL. GSK1325756 solubility dmso Water vapor permeability of polymer and nanofiller decreased when nanocomposite concentration increased. Tensile strength and Elongation at break improved in nanocomposite film by increasing concentration. Thermal properties of CMC/NCH were significantly (p less then 0.05) lower than CMC/NCL. Emersion of crystalline peaks in X-ray analyses certified the presence of nanofiller in polymer. However, in high content (1%) cause to create aggregation of nanofiller in CMC film. Finally antibacterial activity against five pathogens was studied and good effective inhibition on CMC/NCH was observed while CMC/NCL had no inhibitory effect. These results show that use of CMC/NCH as a biocompatible film has more advantages than CMC/NCL biopolymer.The aim of the paper was to investigate the ability of an eco-friendly luminescent xerogel prepared by chitosan crosslinking with a phenothiazine luminogen to detect and remove heavy metals. Its ability to give a divergent morphological and optical response towards fifteen environmental relevant metals was investigated by naked eye and UV lamp, fluorescence spectroscopy and scanning electron microscopy. A distinct response was noted for mercury, consisting in the transformation of the xerogel into a rubber-like material accompanied by the red shifting of the color of emitted light from yellow-green to greenish-yellow domain. The particularities of the metals anchoring into the xerogel were analyzed by FTIR spectroscopy and X-ray diffraction. The morphological changes and the metal uptake were analyzed by SEM-EDAX, swelling and gravimetric methods. It was concluded that mercury has a superior affinity towards this heteroatoms rich system, leading to a secondary crosslinking. This directed a great absorption capacity of 1673 mg/g and a specific morphological response for mercury ion concentrations up to 0.001 ppm.We herein report the synthesis of CuInS2/ZnS (CIS/ZnS) quantum dots (QDs) via a greener method followed by sodium alginate (SA) passivation and encapsulation into mesoporous channels of amine modified silica (SBA15-NH2) for improved photostability and biocompatibility. The as-synthesized CIS/ZnS QDs exhibited near infrared emission even after SA passivation and silica encapsulation. Transmission electron microscopy (TEM) and Small angle X-ray diffraction (XRD) revealed the mesoporous nature of the SBA-15 remained stable after loading with the SA-CIS/ZnS QDs. The effective encapsulation of SA-CIS/ZnS QDs inside the pores of SBA15-NH2 matrix was confirmed by Brunauer-Emmett-Teller (BET) pore volume analysis while the interaction between the QDs and SBA15-NH2 was confirmed using Fourier transform infrared (FTIR) spectroscopy. The photostability of the QDs was greatly enhanced after these modifications. The resultant SA-CIS/ZnS-SBA15-NH2 (QDs-silica) composite possessed remarkable biocompatibility towards lung cancer (A549) and kidney (HEK 293) cell lines making it a versatile material for theranostic applications.The global health emergency generated by coronavirus disease 2019 (COVID-19) has prompted the search for preventive and therapeutic treatments for its pathogen, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There are many potential targets for drug discovery and development to tackle this disease. One of these targets is the main protease, Mpro or 3CLpro, which is highly conserved among coronaviruses. 3CLpro is an essential player in the viral replication cycle, processing the large viral polyproteins and rendering the individual proteins functional. We report a biophysical characterization of the structural stability and the catalytic activity of 3CLpro from SARS-CoV-2, from which a suitable experimental in vitro molecular screening procedure has been designed. By screening of a small chemical library consisting of about 150 compounds, the natural product quercetin was identified as reasonably potent inhibitor of SARS-CoV-2 3CLpro (Ki ~ 7 μM). Quercetin could be shown to interact with 3CLpro using biophysical techniques and bind to the active site in molecular simulations. Quercetin, with well-known pharmacokinetic and ADMET properties, can be considered as a good candidate for further optimization and development, or repositioned for COVID-19 therapeutic treatment.To promote the application of probiotics that are beneficial to hosts, calcium-alginate (Ca-Alg) coated whey protein isolate microcapsules were prepared for protection and delivery of L. bulgaricus and L. paracasei. The internal layer was formed with transglutaminase-induced gelation of whey protein isolate (WPI). Sodium alginate (SA) was applied to form outer layer with external Ca2+ gelation method. The microcapsules loaded with probiotics were characterized by scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC). The results showed that the co-encapsulation efficiency was 90.54% and 84.46% of WPI micro-beads and Ca-Alg-coated microcapsules, respectively. The trehalose was added as cryoprotectant to improve the survival rate of probiotics in freeze-dried Ca-Alg-coated microcapsules from 3% to 41.26%. Ca-Alg-coated microcapsules have regular morphology and intensified structure. The protection of Ca-Alg-coated microcapsule for probiotics was improved under simulated gastrointestinal and thermal conditions.