The application of nano-hydrogels and hydrogels in wound dressings.

Wounds and the healing process are one of the main concerns of medical science today. A wound is any loss of integrity, or rupture of the layers of skin (epidermis, dermis, and hypodermis) or subcutaneous tissue caused by physical factors (surgical incision, trauma, pressure, and gunshot wounds) or chemical factors (acid burns). It is observed that soft tissue, muscle, or bone is involved in occurrences of wounds. Lesions and fractures of the skin surface necessitate medical attention, wherein dressings expedite the healing process by establishing a physical barrier between the wound and the external environment, thereby preventing further injury or infection. Hydrogel dressings create a moist environment that facilitates common healing steps, such as granulation hyperplasia, epidermal repair, and removal of excess dead tissue. The limited adhesion of the hydrogel and the hydrated wound bed allows for easy removal of the dressing without secondary damage, thereby significantly reducing the discomfort and risk of infection during dressing changes. These modern, wet dressings foster a moist healing environment by absorbing excess inflammatory secretions and allowing proper passage of steam and air, which expedites the healing process. In this analysis, the utilization of hydrogels as wound dressings is briefly presented.

Exploring Fully Biobased Adhesives: Sustainable Kraft Lignin and 5-HMF Adhesive for Particleboards.

Most adhesives used in the wood-based panel (WBP) industry are petroleum-based and are associated with environmental impact and price fluctuations. Furthermore, most have potential adverse health impacts, such as formaldehyde emissions. This has led to interest from the WBP industry in developing adhesives with bio-based and/or non-hazardous components. This research focuses on the replacement of phenol-formaldehyde resins by Kraft lignin for phenol substitution and 5-hydroxymethylfurfural (5-HMF) for formaldehyde substitution. Resin development and optimization was carried out regarding varying parameters such as molar ratio, temperature or pH. The adhesive properties were analyzed using a rheometer, gel timer and a differential scanning calorimeter (DSC). The bonding performances were evaluated using an Automated Bonding Evaluation System (ABES). Particleboards were produced using a hot press, and their internal bond strength (IB) was evaluated according to SN EN 319. Hardening of the adhesive could be achieved at low temperatures by increasing or decreasing the pH. The most promising results were obtained at pH 13.7. The adhesive performances were improved by adding filler and extender (up to 28.6% based on dry resin) and several boards were produced reaching P1 requirements. A particleboard achieved a mean IB of 0.29 N/mm2, almost reaching almost P2 requirements. However, adhesive reactivity and strength must be improved for industrial use.

Evaluation of the expression of induced genes in response to dehydration stress of Camelina (Camelina sativa) calli.

Plants are constantly exposed to various biological and non-biological stresses that endanger their lives. Drought stress is one of the abiotic stresses that have a great impact on the yield and life of plants and is one of the main causes of reduced crop yields. Reducing the effects of environmental stresses such as drought using methods such as irrigation, fertilizer application and appropriate planting methods is limited. Therefore, genetic modification of plants is an important effort to minimize the effect of environmental stresses. in this research, Twenty disinfected camelina seeds were cultured on the MS medium containing 3% sucrose, 0.8% agar and pH 5.8 under a laminar hood. After 14 days, the cotyledon explants (about 1 cm) were separated from the seedlings and placed on the callus induction medium. The MS callus induction medium containing 0.5 mg / l kinetin, 2 mg / l -2,4 D, 3% sucrose, 0.8% agar and pH 5.8. Samples were subcultured every two weeks to the same medium and calli were formed after 4 weeks. Then the calli were transferred to the medium containing a concentration of 30% PEG. To study gene expression, first callus samples were treated with liquid nitrogen and to study the effect of drought stress on gene expression, this sample was sent to Zagros Bioidea Company located in the Razi University Incubator. Gene expression was performed through microarray technology. The results showed that seven different genes whose expression increased by almost six times the control value can be mentioned, including Cold-acclimation protein (CAP160), NAC10, Abscisic acid (ABA), ABF4, CRK3, lysM domain receptor-like kinases (LYKs) and Basic/helix-loop-helix(bHLH130-like). Drought tolerance is not a genetically simple trait, but a quantitative and complex trait with various aspects that require the use of molecular methods to investigate the relevant mechanisms. This study aimed to investigate the expression of different genes of callus tissues of the Camelina plant under stress and non-stress conditions by microarray method.

Ammoxidized Fenton-Activated Pine Kraft Lignin Accelerates Synthesis and Curing of Resole Resins.

Ammoxidation of pine kraft lignin in aqueous 5 wt % ammonia affords a novel type of phenol substitute that significantly accelerates resole synthesis and curing as demonstrated for 40 wt % phenol replacement. Compared to non-ammoxidized lignin, which already shortens significantly the cooking time required to reach a resole viscosity of 1000 Pa·s (250 vs. 150 s) and reduces the typical curing B-time by about 25% at 100 °C, the use of ammoxidized lignin has an even more pronounced impact in this respect. Activation of lignin by Fenton-type oxidation prior to ammoxidation further boosts both synthesis and curing of the resole. This is presumably due to the intermediary formation of polyvalent cross-linkers like N,N,N-tris (methylol) trimethylene triamine triggered by saponification of a larger fraction of nitrogenous moieties present in such a treated lignin (ammonium salts, amide-type nitrogen, urea) and reaction of the released ammonia with formaldehyde. Except for the fact that phenol replacement by ammoxidized lignin results in a somewhat less brittle cured adhesive polymer and higher elastic modulus, the aforementioned acceleration in curing could no longer be observed in the presence of wood, where a significantly delayed wood-adhesive bond formation was observed for the lignin-containing adhesives as evident from the automated bonding evaluation system.