Ethological studies of the Veined Octopus <i>Amphioctopus marinates</i> (Taki) (Cephalopoda: Octopodidae) in captivity, Kerala, India

Five Veined Octopus Amphioctopus marginatus (Taki), collected from Vizhinjam Bay in the Thiruvananthapuram District of Kerala, India were kept in aquariums to study their behaviour in captivity. Primary and secondary defence mechanisms studied included crypsis, hiding and escape behaviour. Deimatic behaviour was used by captive animals when camouflage failed and they were threatened. Crawling behaviour to escape from the aquarium was observed in all specimens. Stilt walking and bi-pedal locomotion were also observed. As a defence behaviour, A. marginatus used aquarium rocks to protect the soft underside of their bodies. A. marginatus demonstrated tool use of coconut shells to make protective shelters, carrying the shells for future use. A female specimen also selected a coconut shell for egg laying and performed parental care by continuously cleaning and aerating her eggs with her arms and by squirting jets of water over the eggs

Parameters and characteristics governing cellular internalization and trans-barrier trafficking of&nbsp;nanostructures

Karmani Murugan, Yahya E Choonara, Pradeep Kumar, Divya Bijukumar, Lisa C du Toit, Viness Pillay Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa Abstract: Cellular internalization and trans-barrier transport of nanoparticles can be manipulated on the basis of the physicochemical and mechanical characteristics of nanoparticles. Research has shown that these factors significantly influence the uptake of nanoparticles. Dictating these characteristics allows for the control of the rate and extent of cellular uptake, as well as delivering the drug-loaded nanosystem intra-cellularly, which is imperative for drugs that require a specific cellular level to exert their effects. Additionally, physicochemical characteristics of the nanoparticles should be optimal for the nanosystem to bypass the natural restricting phenomena of the body and act therapeutically at the targeted site. The factors at the focal point of emerging smart nanomedicines include nanoparticle size, surface charge, shape, hydrophobicity, surface chemistry, and even protein and ligand conjugates. Hence, this review discusses the mechanism of internalization of nanoparticles and ideal nanoparticle characteristics that allow them to evade the biological barriers in order to achieve optimal cellular uptake in different organ systems. Identifying these parameters assists with the progression of nanomedicine as an outstanding vector of pharmaceuticals. Keywords: nanoparticles, transport mechanisms, cellular uptake, size, shape, charg

A new corner reflector antenna with periodic strip subreflectors

This paper presents the design of a new type of corner reflector (CR) antenna and the experimental investigation of its radiation characteristics. The design involves the addition of planar parallel periodic strips to the two sides of a CR antenna. The position, angular orientation, and number of strips have a notable effect on the H-plane radiation characteristics of the antenna. Certain configurations of the new antenna are capable of producing very sharp axial beams with gain on the order of 5 dB over the square corner reflector antenna. A configuration that can provide symmetric twin beams with enhanced gain and reduced half-power beam width (HPBW) is also presented.Mahatma Gandhi University & Cochin University of Science and Technolog

Customized Peptide Biomaterial Synthesis via an Environment-Reliant Auto-Programmer Stigmergic Approach

Stigmergy, a form of self-organization, was employed here to engineer a self-organizing peptide capable of forming a nano- or micro-structure and that can potentially be used in various drug delivery and biomedical applications. These self-assembling peptides exhibit several desirable qualities for drug delivery, tissue engineering, cosmetics, antibiotics, food science, and biomedical surface engineering. In this study, peptide biomaterial synthesis was carried out using an environment-reliant auto-programmer stigmergic approach. A model protein, &alpha;-gliadin (31, 36, and 38 kD), was forced to attain a primary structure with free &ndash;SH groups and broken down enzymatically into smaller fragments using chymotrypsin. This breakdown was carried out at different environment conditions (37 and 50 &deg;C), and the fragments were allowed to self-organize at these temperatures. The new peptides so formed diverged according to the environmental conditions. Interestingly, two peptides (with molecular weights of 13.8 and 11.8 kD) were isolated when the reaction temperature was maintained at 50 &deg;C, while four peptides with molecular weights of 54, 51, 13.8, and 12.8 kD were obtained when the reaction was conducted at 37 &deg;C. Thus, at a higher temperature (50 &deg;C), the peptides formed, compared to the original protein, had lower molecular weights, whereas, at a lower temperature (37 &deg;C), two peptides had higher molecular weights and two had lower molecular weights

Synthesis and Evaluation of a Sodium Alginate-4-Aminosalicylic Acid Based Microporous Hydrogel for Potential Viscosupplementation for Joint Injuries and Arthritis-Induced Conditions

A microporous hydrogel was developed using sodium alginate (alg) and 4-aminosalicylic acid (4-ASA). The synthesized hydrogel was characterized using various analytical techniques such as Fourier transform infrared spectroscopy (FTIR), Carbon-13 nuclear magnetic resonance (13C-NMR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). Additonal carboxyl and hydroxyl functional groups of 4-ASA provided significant lubrication and stress-triggered sol-gel transition to the conjugated hydrogel. In addition, cytotoxicity analysis was undertaken on the conjugated hydrogel using human dermal fibroblast-adult (HDFa) cells, displaying non-toxic characteristics. Drug release profiles displaying 49.6% in the first 8 h and 97.5% within 72 h, similar to the native polymer (42.8% in first 8 h and 90.1% within 72 h). Under applied external stimuli, the modified hydrogel displayed significant gelling properties and structure deformation/recovery behaviour, confirmed using rheological evaluation (viscosity and thixotropic area of 8095.3 mPas and 26.23%, respectively). The modified hydrogel, thus, offers great possibility for designing smart synovial fluids as a biomimetic aqueous lubricant for joint-related injuries and arthritis-induced conditions. In addtion, the combination of thixotropy, non-toxicity, and drug release capabilities enables potential viscosupplementation for clinical application