Effect of copper and titanium-exchanged montmorillonite nanostructures on the packaging performance of chitosan/poly-vinyl-alcohol-based active packaging nanocomposite films

In this study, CuMt and TiMt montmorillonites were produced via an ion-exchange process with Cu+ and Ti4+ ions. These nanostructured materials were characterized with X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR) measurements and added as nanoreinforcements and active agents in chitosan (CS)/poly-vinyl-alcohol (PVOH)-based packaging films. The developed films were characterized by XRD and FTIR measurements. The antimicrobial, tensile, and oxygen/water-barrier measurements for the evaluation of the packaging performance were carried out to the obtained CS/PVOH/CuMt and CS/PVOH/TiMt films. The results of this study indicated that CS/PVOH/CuMt film is a stronger intercalated nanocomposite structure compared to the CS/PVOH/TiMt film. This fact reflected higher tensile strength and water/oxygen-barrier properties. The antibacterial activity of these films was tested against four food pathogenic bacteria: Escherichia coli, Staphylococcus aureus, Salmonella enterica and Listeria monocytogenes. Results showed that in most cases, the antibacterial activity was generated by the CuMt and TiMt nanostructures. Thus, both CS/PVOH/CuMt and CS/PVOH/TiMt films are nanocomposite candidates with very good perspectives for future applications on food edible active packaging. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Tubulointerstitial nephritis and uveitis (TINU) syndrome in a 52-year-old female: A case report and review of the literature

Tubulointerstitial nephritis and uveitis (TINU) syndrome is a rare entity first described in 1975, affecting mainly young women and adolescents. We present a case of a 52-year-old female patient (one of the oldest in the literature) who complained of fever, anorexia, nausea, and vomiting. After she was admitted to our hospital, laboratory tests revealed tubular proteinuria, elevated erythrocyte sedimentation rate (ESR), anemia, and renal insufficiency (serum creatinine 4.2 mg/dL) with metabolic acidosis. Ophthalmologic examination revealed anterior uveitis (iritis) and renal biopsy showed acute tubulointerstitial nephritis. The diagnosis of TINU syndrome was established and the patient was treated with oral corticosteroids. All symptoms and ophthalmologic abnormalities disappeared after 6 weeks of treatment. Renal function also recovered completely and remained stable at follow-up. TINU syndrome should be considered in the differential diagnosis of unexplained tubulointerstitial nephritis, especially in the presence of ocular findings. Corticosteroid therapy is still controversial, but it helps in the quick resolution of renal and mainly eye abnormalities. Copyright © Taylor & Francis Group, LLC

Nanoclay and polystyrene type efficiency on the development of polystyrene/montmorillonite/oregano oil antioxidant active packaging nanocomposite films

Over the years, there has been an effort to extend food shelf life so as to reduce global food waste. The use of natural biodegradable materials in production procedures is more and more adopted nowadays in order to achieve cyclic economy targets and improve environmental and human health indexes. Active packaging is the latest trend for food preservation. In this work, polystyrene was mixed with natural NaMt, OrgNaMt montmorillonite, and oregano essential oil to de-velop a new packaging film. Strength, oxygen and water-vapour permeation, blending and homo-geneity, and antimicrobial and antioxidant activity were measured as basic parameters for food packaging films characterization. Instruments such as a tensile measurement instrument, XRD, FTIR, DMA, OPA (Oxygen Permeation Analyzer), and other handmade devices were used. Results showed that polystyrene could be modified, improved, and exhibits food odour prevention characteristics in order to be used for applications on food active packaging. The material with the code name PS5OO@OrgMt qualified between the tested samples as the most promising material for food active packaging applications. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Performance of Thyme Oil@Na-Montmorillonite and Thyme Oil@Organo-Modified Montmorillonite Nanostructures on the Development of Melt-Extruded Poly-L-lactic Acid Antioxidant Active Packaging Films

Today, the use of natural biodegradable materials in the production processes is more and more adopted by industry to achieve cyclic economy targets and to improve environmental and human health indexes. Active packaging is the latest trend for food preservation. In this work, nanostructures were prepared by incorporation of thyme oil with natural natrium-montmorillonite and organo-montmorillonite with two different techniques, direct impregnation and the green evaporation–adsorption process. Such nanostructures were mixed with poly-L-lactic-acid for the first time via an extrusion molding process to develop a new packaging film. Comparisons of mor-phological, mechanical, and other basic properties for food packaging were carried out via XRD, FTIR, TG, SEM/EDS, oxygen and water vapor permeation, and antimicrobial and antioxidant activity for the first time. Results showed that poly-L-lactic-acid could be modified with clays and essential oils to produce improved active packaging films. The final product exhibits food odor prevention characteristics and shelf-life extension capabilities, and it could be used for active packaging. The films based on OrgMt clay seems to be more promising, while the thyme oil addition improves their behavior as active packaging. The PLLA/3%TO@OrgMt and PLLA/5%TO@OrgMt films were qualified between the tested samples as the most promising materials for this purpose. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Leveraging NMR and X-ray data of the free ligands to build better drugs targeting angiotensin II Type 1 G-Protein coupled receptor

The angiotensin II type 1 receptor (AT1R) has been recently crystallized. A new era has emerged for the structure-based rational drug design and the synthesis of novel AT1R antagonists. In this critical review, the X-ray crystallographic data of commercially available AT1R antagonists in free form are analyzed and compared with the conformational analysis results obtained using a combination of NMR spectroscopy and Molecular Modeling. The same AT1R antagonists are docked and compared in terms of their interactions in their binding site using homology models and the crystallized AT1R receptor. Various aspects derived from these comparisons regarding rational drug design are outlined. © 2016 Bentham Science Publishers