Magnetic micro-swimmers propelling through bio-rheological liquid bounded within an active channel

The dynamics of a micro-organism swimming through a channel with undulating walls subject to constant transverse applied magnetic field is investigated. The micro-organism is modeled as self-propelling undulating sheet which is out of phase with the channel waves while the electrically conducting biofluid (through which micro-swimmers propel) is characterized by the non-Newtonian shear-rate dependent Carreau fluid model. Creeping flow is mobilized in the channel due to the self-propulsion of the micro-organism and the undulatory motion of narrow gapped walls. Under these conditions the conservation equations are formulated under the long wavelength and low Reynolds number assumptions. The speed of the self-propelling sheet and the rate of work done at higher values of rheological parameters are obtained by using a hybrid numerical technique (MATLAB routine bvp-4c combined with a modified Newton-Raphson method). The results are validated through an alternative hybrid numerical scheme (implicit finite difference method (FDM) in conjunction with a modified Newton-Raphson method). The assisting role of magnetic field and rheological effects of the surrounding biofluid on the swimming mode are shown graphically and interpreted at length. The global behavior of biofluid is also expounded via visualization of the streamlines in both regions (above and below the swimming sheet) for realistic micro-organism speeds. The computations reveal that optimal swimming conditions for the micro-organism (i.e., greater speed with lower energy losses) are achievable in magnetohydrodynamic (MHD) environments including magnetic field-assisted cervical treatments. Keywords: Micro-organism; peristaltic (active) channel; Carreau fluid; Swimming speed; biomagnetohydrodynamics (bioMHD); Rate of work done; Hybrid numerical method, Newton-Raphson method; Cervical magnetic therap

Current Perspectives in NSAID-Induced Gastropathy

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most highly prescribed drugs in the world. Their analgesic, anti-inflammatory, and antipyretic actions may be beneficial; however, they are associated with severe side effects including gastrointestinal injury and peptic ulceration. Though several approaches for limiting these side effects have been adopted, like the use of COX-2 specific drugs, comedication of acid suppressants like proton pump inhibitors and prostaglandin analogs, these alternatives have limitations in terms of efficacy and side effects. In this paper, the mechanism of action of NSAIDs and their critical gastrointestinal complications have been reviewed. This paper also provides the information on different preventive measures prescribed to minimize such adverse effects and analyses the new suggested strategies for development of novel drugs to maintain the anti-inflammatory functions of NSAIDs along with effective gastrointestinal protection

Preparation and antimicrobial action of three tryptic digested functional molecules of bovine lactoferrin.

Lactoferrin is an 80 kDa bilobal, iron binding glycoprotein which is primarily antimicrobial in nature. The hydrolysis of lactoferrin by various proteases in the gut produces several functional fragments of lactoferrin which have varying molecular sizes and properties. Here, bovine lactoferrin has been hydrolyzed by trypsin, the major enzyme present in the gut, to produce three functional molecules of sizes approximately 21 kDa, 38 kDa and 45 kDa. The molecules have been purified using ion exchange and gel filtration chromatography and identified using N-terminal sequencing, which reveals that while the 21 kDa molecule corresponds to the N2 domain (21LF), the 38 kDa represents the whole C-lobe (38LF) and the 45 kDa is a portion of N1 domain of N-lobe attached to the C-lobe (45LF). The iron binding and release properties of 21LF, 38LF and 45LF have been studied and compared. The sequence and structure analysis of the portions of the excision sites of LF from various species have been done. The antibacterial properties of these three molecules against bacterial strains, Streptococcus pyogenes, Escherichia coli, Yersinia enterocolitica and Listeria monocytogenes were investigated. The antifungal action of the molecules was also evaluated against Candida albicans. This is the first report on the antimicrobial actions of the trypsin cleaved functional molecules of lactoferrin from any species

Zone of diameters of LF, 21LF, 38LF and 45LF against <i>Candida albicans</i>.

<p>Zone of diameters of LF, 21LF, 38LF and 45LF against <i>Candida albicans</i>.</p

Elution profile during the purification of the hydrolyzate of bovine LF after trypsin digestion.

<p>Elution was performed using ion exchange chromatography by CM-Sephadex C-50 in 0.05 M Tris-HCl, pH 8.0. Peak 1 indicates the unbound fraction while Peak 2 is eluted in the bound fraction.</p

Zone of inhibitions against <i>C. albicans</i> ATCC 90028.

<p>A corresponds to Fluconazole (positive control), B corresponds to 21LF, C corresponds to 38LF, D corresponds to 45LF, E corresponds to LF and F corresponds to blank.</p

Superimposition of the backbone chains of iron-saturated LFs from various species.

<p>The figure shows that the overall chain folds in a similar fashion in all the species.</p

The entire sequence of bovine native LF.

<p>Arrows [blue (21LF), green (38LF), red (45LF)] indicate the origin sites of the three fragments respectively. The amino acid sequence of the first fifteen residues of 21LF, 38LF and 45LF is indicated against their names towards the left,</p

Zone of diameters of LF, 21LF, 38LF and 45LF against bacterial species.

<p>Zone of diameters of LF, 21LF, 38LF and 45LF against bacterial species.</p