Narrow Results

Convective flowing and heat transference of non-Newtonian liquid comprising nano-encapsulated phase-changing material (NEPCM) suspensions, filled in a square cavity, is numerically investigated. The molecules of NEPCM are cored with n-octadecane, shelled by polymethyl-methacrylate, and suspended in non-Newtonian fluid. The enclosure is insulated horizontally and heated vertically. Finite element method (FEM) is implemented for the numerical solution under different variables such as nanoparticles volume fraction ($0<\varnothing <0.05$), Stefan number ($\mathrm{\text{Ste}}=0.2,0.313,0.5$), the heat capacity ratio ($\lambda$) of about (0.4), the temperature of fusion of the NEPCM ($0<{\theta }_f<1$) and the density ratio (${\rho }_P∕{\rho }_f$) ($0.7<{\rho }_P∕{\rho }_f\le 0.9$). The results show that the Nusselt quantity is related to the fusion temperature. An improvement in heat transference is observed when the fusion temperature deviates from the wall temperature, which is in the range of $0.25<{\theta }_f<0.75$. For all power law index values (n), a linear increase of the Nusselt number with the solid volume fraction is detected. The shear-thinning nanofluid ($n=0.6$) demonstrates higher Nusselt number values than those of $n=1$ and 1.4.

Iron oxide-based magnetic nanoparticles (IONPs) have received remarkable attention in a wide range of applications because of their unique physicochemical properties’ inheritance to the nanoscale. Among these nanoparticles (NPs), superparamagnetic iron oxide nanoparticles (SPIONs), as powerful noninvasive NPs, are widely used in nanomedicine applications such as targeted drug/ gene delivery, magnetic separation, cancer therapy, and magnetic resonance imaging (MRI) hyperthermia because of their superparamagnetic activity and remarkable small size. The synthesis of SPIONs and surface modification of these NPs for biological applications is an interesting research topic. These NPs have high magnetic susceptibility, a single magnetic domain, and a controlled magnetic behavior due to the SPION superparamagnetic feature. This review aims to explore the recently developed synthetic routes of SPIONs and show the best parameters to prepare SPIONs using pulsed laser ablation in liquid “PLAL” for biomedical applications. Furthermore, we highlight the properties, coating, and functionalization of SPIONs and their importance for biomedical applications, including targeted drug delivery and cancer therapy.

Polyhemoglobin-superoxide dismutase-catalase-carbonic anhydrase (poly-[Hb-SOD-CAT-CA]) contains all three major functions of red blood cells (RBCs) at an enhanced level. It transports oxygen, removes oxygen radicals and transports carbon dioxide. Our previous studies in a 90-minute 30 mm Hg MAP-sustained hemorrhagic shock rat model showed that it was more effective than blood in the lowering of elevated intracellular PCO₂, recovery of ST-elevation and histology of the heart and intestine. This paper analyzes the storage and temperature stability. The allowable storage time for RBCs is about 1 day at room temperature and 42 days at 4°C. Also, RBCs cannot be pasteurized to remove infective agents like HIV and Ebola. PolyHb can be heat sterilized and can be stored for a year even at room temperature. However, poly-[Hb-SOD-CAT-CA] contains both Hb and enzymes, and enzymes are particularly sensitive to storage and heat. We thus carried out studies to analyze its storage stability at different temperatures and heat pasteurization stability. The results of the storage stability show that lyophillization extends the storage time to a year at 4°C and 40 days at room temperature (compared to 42 days and 1 day, respectively, for RBCs). After the freeze-dry process, the enzyme activities of poly-[SFHb-SOD-CAT-CA] was 100 ± 2% for CA, 100 ± 2% for SOD, and 93 ± 3.5% for CAT. After heat pasteurization at 70°C for 2 hours, lyophilized poly-[Hb-SOD-CAT-CA] retained good enzyme activities of CA (97 ± 4%), SOD (100 ± 2.5%) and CAT (63.8 ± 4%). More CAT can be added during the crosslinking process to maintain the same enzyme ratio after heat pasteurization. Heat pasteurization is possible only for the lyophilized form of poly-[Hb-SOD-CAT-CA] and not for the solution. It can be easily reconstituted by dissolving it in suitable solutions that continue to have good storage stability (though less than that for the lyophilized form). According to the P50 value, poly-[SFHb-SOD-CAT-CA] retains its oxygen-carrying ability before and after long-term storage.