Direct and Indirect Cationization of Cellulose Nanocrystals: Structure-Properties Relationship and Virus Capture Activity.

Due to increasing public concern over hygiene, there have been many studies investigating antimicrobial and antiviral agents recently. With the aim of developing biobased virucidal/virus capture agents, we report a chemical modification of the cellulose nanocrystals (CNCs) surface with poly(2-dimethylamino) ethyl acrylate) methyl chloride quaternary salt (Q-PDMAEA) to introduce the positively charged functional groups. The surface of CNCs was modified through direct and indirect graft polymerization. Subsequently, the direct and indirect cationization effect on the degree of functionalization, thermal stability, crystallinity, and antiviral activity of CNCs was investigated. Indirect cationization produced the highest degree of polymer grafting, increasing particle size and thermal stability. Further, the modified CNCs were tested for their ability to capture nonenveloped bacteriophages PhiX174 (ΦX174) and MS2. We observed a significant (>4.19 log10) reduction in total viral load by specific functionalized CNCs. However, the activity depended on the structure of functional groups, surface charge density, and the type of virus under study. Overall, the direct and indirect cationization of CNC leads to biobased agents with immobilized cationic charge, with good virus capture activity. Such agents can be used for various applications including textiles, packaging, wastewater treatment, etc.

Comparing the Efficacy of Sequential and Standard Quadruple Therapy for Eradication of H. Pylori Infection.

BACKGROUND: The aim of this study was comparison the effectiveness of sequential and standard quadruple therapy on eradication of H. pylori infection. METHODS: This clinical trial study was conducted on 160 patients with dyspepsia or gastroduodenal ulcer. Patients were randomly divided into two groups. Group A (standard regimen) received omeprazole, amoxicillin, clarithromycin and bismuth subcitrate for 2 weeks. Group B (sequential regimen) received omeprazole and amoxicillin in 5 days and omeprazole, tinidazole and levofloxacin in 5 days. After the end of treatment regimens, 20 mg omeprazole was administered twice daily for 3 weeks. H. pylori eradication was assessed 2 months after antibiotic treatment via fecal antigen. RESULTS: Frequency of H. pylori eradication in group A and B was observed in 55 (68.8%) and 63 patients (78.8%), respectively. No significant difference was seen between two groups, regarding H. pylori eradication (p = 0.15). The most common side effects in group A, B were bitterness of mouth (63.8%) and nausea (16.2%), respectively (p H. pylori infection, higher rate of H. pylori eradication was seen in group B than group A. Thus, sequential regimen was a more appropriate regimen with fewer complications.

Functionalized-MnO2/chitosan nanocomposites: A promising adsorbent for the removal of lead ions.

In the current study, the surface of alpha manganese dioxide nanorod (α-MnO2) functionalized with γ-aminopropyltriethoxysilane (APTS). The α-MnO2-APTS was used as filler for preparation of chitosan (CS) nanocomposites (NCs). The α-MnO2-APTS/CS NCs were crosslinked with different amount of glutaraldehyde (GA). The effects of the GA content on the morphology, thermal properties and adsorption of NC films were studied. The Fourier transform infrared (FT-IR) results verified the grafting of APTS onto α-MnO2. The amount of APTS grafted onto α-MnO2 was found to be 20wt% by thermo gravimetric analysis. Presented results also show that with increasing crosslinker agent concentration, the thermal stability of CS films were increased. The α-MnO2-APTS/CS NCs were tested and evaluated as a potential adsorbent for the removal of lead ions. The results showed that the adsorbent exhibited a favorable performance for the removal of lead ions. Therefore, α-MnO2-APTS/CS NCs could serve as promising adsorbents.