Topology Based Surface Meshing and Morphing

posterMorphing is a seamless transition from one image to the other, used in animation and motion pictures. Mesh Parameterization used in this process is a fundamental tool used for domain remeshing. In case of 2-manifolds for example, most approaches require that the input mesh be cut into one or more open disks prior to computing a parameterization. When it is cut into single disk, it gives way to intrinsic distortions and when cut into multiple disks, the resulting parameterization is not globalized. Hence a novel approach to parameterize 2-manifold meshes of arbitrary genus to a standard domain by defining two independent piecewise linear Morse functions on the mesh is proposed

Biogenesis of silver nanoparticles using selected plant leaf extract; characterization and comparative analysis of their antimicrobial activity

Objective(s): To study the antimicrobial property of green synthesised silver nano metals with M.balbisiana, A.indica and O.tenuiflorm and their enhanced antibacterial activity, assessment of antimicrobial effect. And to explore the possible mechanism of AgNPs synthesis in the active constitutions of selected temperate plant extracts Materials and methods:Biosynthesis of AgNPs using plant extract was carried out and formation of AgNPs confirmed by perceptible observation, UV spectroscopy, Scanning electron microscope (SEM) and Dynamic light scattering (DLS) were used to characterize the AgNPs.  Results:Screening of the M.balbisiana, A.indica and O.tenuiflorm extracts was carried out using standard methods to find their constitutions. The antibacterial screening was carried out by agar well diffusion method against selected microorganisms. The absorption maxima of UV visible spectrum found in the range between 300 nm to 800 nm confirmed the formation of AgNPs. SEM images revealed relatively spherical shaped of AgNPs of biosynthesized AgNPs with mean diameter about 14.51±1.5nm in O.tenuiflourum, 09.10±1.50nm M.barbisiana and 11.00±1.50 in A indica. FTIR results expounded the functional groups of plant extract responsible for the bio-reduction of silver ions and their interaction between them. Conclusion:These results showed with changes in plants constituents are may be responsible to form nanoparticles with different size and characteristic

Antibiofilm Properties of Interfacially Active Lipase Immobilized Porous Polycaprolactam Prepared by LB Technique

<div><p>Porous biomaterial is the preferred implant due to the interconnectivity of the pores. Chances of infection due to biofilm are also high in these biomaterials because of the presence of pores. Although biofilm in implants contributes to 80% of human infections <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0096152#pone.0096152-Rmling1" target="_blank">[1]</a>, there are no commercially available natural therapeutics against it. In the current study, glutaraldehyde cross linked lipase was transferred onto a activated porous polycaprolactam surface using Langmuir-Blodgett deposition technique, and its thermostability, slimicidal, antibacterial, biocompatibility and surface properties were studied. There was a 20% increase in the activity of the covalently crosslinked lipase when compared to its free form. This immobilized surface was thermostable and retained activity and stability until 100°C. There was a 2 and 7 times reduction in carbohydrate and 9 and 5 times reduction in biofilm protein of <i>Staphylococcus aureus</i> and <i>Escherichia coli</i> respectively on lipase immobilized polycaprolactam (LIP) when compared to uncoated polycaprolactam (UP). The number of live bacterial colonies on LIP was four times less than on UP. Lipase acted on the cell wall of the bacteria leading to its death, which was confirmed from AFM, fluorescence microscopic images and amount of lactate dehydrogenase released. LIP allowed proliferation of more than 90% of 3T3 cells indicating that it was biocompatible. The fact that LIP exhibits antimicrobial property at the air-water interface to hydrophobic as well as hydrophilic bacteria along with lack of cytotoxicity makes it an ideal biomaterial for biofilm prevention in implants.</p></div

Fluorescence microscopic images of <i>E.coli</i> and <i>S.aureus</i> formed on UP (A & C) and LIP (B & D) surfaces respectively after 24 h of incubation.

<p>Green dots represent live and red colour represents dead cells.</p

Biofilm formed on UP and LIP surface (A) CFU, (B) carbohydrate and (C) protein (**p<0.001; *p<0.01).

<p>SEM images of (D) <i>S.aureus</i> adhered on UP and (E) LIP surfaces after 24 hr. AFM images of <i>E.coli</i> on (F) UP and (G) LIP.</p

Effect of glutaraldehyde concentration and time on lipase activity (4000 Units of lipase was used for crosslinking) at a pH of 4.5 (3.4 gm of monobasic sodium phosphate was dissolved in 1 liter of water and adjusted with 10 N (KOH) to yield a 25 mM phosphate buffer of pH 4.5).

<p>Effect of glutaraldehyde concentration and time on lipase activity (4000 Units of lipase was used for crosslinking) at a pH of 4.5 (3.4 gm of monobasic sodium phosphate was dissolved in 1 liter of water and adjusted with 10 N (KOH) to yield a 25 mM phosphate buffer of pH 4.5).</p

Zeta potential and mobility of bacteria on UP and LIP surfaces.

<p>Zeta potential and mobility of bacteria on UP and LIP surfaces.</p

AFM images of surfaces of (A) polycaprolactam (UP), (B) lipase coated polycaprolactam (LCP) after buffer wash (C) lipase immobilized polycaprolactam (LIP) after buffer wash.

<p>(D) FTIR spectra of UP and LIP.</p

Micrographs showing 3T3 cells on the UP surface (A & C) and LIP surface (B & D).

<p>Micrographs showing 3T3 cells on the UP surface (A & C) and LIP surface (B & D).</p

Hydrophobicity of microorganisms measured at varying volumes of hexadecane (BATH test) (A).

<p>Slimicidal activity of various concentrations of lipase against <i>E.coli</i> and <i>S.aureus</i> (B). Surface pressure-area isotherm (at a pH of 4.5 and 25°C) while preparing Lipase immobilized polycaprolactam (LIP) with different lipase amounts and 0.25% glutaraldehyde (C). Surface pressure-area isotherm of Lipase coated polycaprolactam (LCP) after optimization (D).</p