Physico-chemical studies of micelle formation on sepia cartilage collagen solutions in acetate buffer and its interaction with ionic and nonionic micelles

Sepia cartilage collagen (pepsin-extracted) in acetate buffer (pH = 2.98) forms micelles at a particular concentration below which they do not normally form. The critical micelle concentration (cmc) of the collagen was determined in buffer as well as in SDS, cetyltrimethylammonium bromide (CTAB) and Tween-80 micellar environments at different temperatures. Mutual interaction of collagen micelles with the ionic and nonionic micelles through the formation of the mixed micelle concept has also been found. The cmc of collagen decreased in the presence of SDS and Tween-80 micelles whereas it increased in the presence of CTAB micelles. This clearly suggests that the micelle formation of collagen is facilitated by the presence of SDS and Tween-80 and hindered by CTAB micelles. The various thermodynamic parameters were estimated from viscosity measurements and the transfer of collagen into the micelles of various surfactants and the reverse phenomenon was analyzed. This analysis has also been modelled conceptually as a different phase and the results have supported the above phenomenon. Our thermodynamic results are also able to predict the exact denaturation temperature as well as the structural order of water in the collagen in various environments. The hydrated volumes, Vh, of collagen in the above environments and intrinsic viscosity were also calculated. The low intrinsic viscosity, [η], of collagen in an SDS environment compared to buffer and other surfactant environments suggested more workable systems in cosmetic and dermatological skin care preparations. The one and two-hydrogen-bonded models of this collagen in various environments have been analyzed. The calculated thermodynamic parameters varied with the concentration of collagen. The change of thermodynamic parameters from coil-coil to random-coil conformation upon denaturation of collagen were calculated from the amount of proline and hydroxyproline residues and compared with viscometric results. Thermodynamic results suggest that the stability of the collagen in the additive environments is in the following order: SDS > Tween-80 > buffer > CTAB

The formation of copper oxide nanorods in the presence of various surfactant micelles

Copper oxide nanorods with average diameters and lengths of ca. 8 nm and 400 nm, respectively, have been prepared by a simple onestep solid-state reaction in the presence of various surfactant micelles. The effect of three different surfactants viz., SDS, CTAB and Triton X-100 and their critical micellar concentration (CMC) on the formation of nanorods has been studied using XRD, TEM, DSC and XPS techniques. It is found that the formation of the nanorods in the presence of SDS micelles is better with higher thermal stability and possessing lower binding energy with regard to Cu2p peak

Infant- and Young Child-feeding Practices in Bankura District, West Bengal, India

A community-based, cross-sectional descriptive study was conducted during June-July 2008 to assess the infant- and young child-feeding (IYCF) practices in Bankura district, West Bengal, India. In total, 647 children aged less than two years selected through revised 40-cluster sampling using the indicators of the Integrated Management of Neonatal and Childhood Illness (IMNCI) and World Health Organization. The proportions of infants with early initiation of breastfeeding (13.6%) and exclusive breastfeeding under six months (57.1%) and infants who received complementary feeding at the age of 6–8 months (55.7%) were low. Appropriate feeding as per the IMNCI protocol was significantly less among infants aged 6–11 months (15.2%) and children aged 12–23 months (8.7%) compared to infants aged less than six months (57.1%), which could be attributable to low frequency and amount of complementary feeding. The main problems revealed from the study were late initiation of breastfeeding, low rates of exclusive breastfeeding, and inappropriate complementary feeding practices

Antimicrobial Behavior of Biosynthesized Silica-Silver Nanocomposite for Water Disinfection: A Mechanistic Perspective

The biosynthesis of nano-silica silver nanocomposite (NSAgNC) and it’s as antibacterial effect on gram-negative bacteria viz. Escherichia coli and Pseudomonas aeruginosa has been investigated for disinfection of water. The as-synthesized NSAgNC exhibited antibacterial activity in a dose dependent manner and ~99.9% of E. coli and P. aeruginosa were killed at a concentration of 1.5 mg/mL of NSAgNC (5.1 wt% Ag) within 5 h. The NSAgNC showed similar antibacterial activities both in oxic and anoxic conditions. The results further demonstrated that NSAgNC exhibited reactive oxygen species (ROS) independent “particle specific” antibacterial activity through multiple steps in absence of leached out Ag+ ions. The initial binding of NSAgNC on the cell wall caused loss of cell membrane integrity and leakage of cytoplasmic materials. Inhibition of respiratory chain dehydrogenase by NSAgNC caused metabolic inactivation of the cells and affecting the cell viability. Genomic and proteomic studies further demonstrated the fragmentations of both plasmid and genomic DNA and down regulation of protein expression in NSAgNC treated cells, which leading to the cell death. Thus the biosynthesized NSAgNC has great potential as disinfectant for water purification while minimizing the toxic effects

Infant- and young child-feeding practices in Bankura district, West Bengal, India

A community-based, cross-sectional descriptive study was conducted during June-July 2008 to assess the infant- and young child-feeding (IYCF) practices in Bankura district, West Bengal, India. In total, 647 chil-dren aged less than two years selected through revised 40-cluster sampling using the indicators of the Integrated Management of Neonatal and Childhood Illness (IMNCI) and World Health Organization. The proportions of infants with early initiation of breastfeeding (13.6%) and exclusive breastfeeding under six months (57.1%) and infants who received complementary feeding at the age of 6-8 months (55.7%) were low. Appropriate feeding as per the IMNCI protocol was significantly less among infants aged 6-11 months (15.2%) and children aged 12-23 months (8.7%) compared to infants aged less than six months (57.1%), which could be attributable to low frequency and amount of complementary feeding. The main problems revealed from the study were late initiation of breastfeeding, low rates of exclusive breastfeeding, and inap-propriate complementary feeding practices

Bioinformatics in crosslinking chemistry of collagen with selective cross linkers

<p>Abstract</p> <p>Background</p> <p>Identifying the molecular interactions using bioinformatics tools before venturing into wet lab studies saves the energy and time considerably. The present study summarizes, molecular interactions and binding energy calculations made for major structural protein, collagen of Type I and Type III with the chosen cross-linkers, namely, coenzyme Q₁₀, dopaquinone, embelin, embelin complex-1 & 2, idebenone, 5-O-methyl embelin, potassium embelate and vilangin.</p> <p>Results</p> <p>Molecular descriptive analyses suggest, dopaquinone, embelin, idebenone, 5-O-methyl embelin, and potassium embelate display nil violations. And results of docking analyses revealed, best affinity for Type I (- 4.74 kcal/mol) and type III (-4.94 kcal/mol) collagen was with dopaquinone.</p> <p>Conclusions</p> <p>Among the selected cross-linkers, dopaquinone, embelin, potassium embelate and 5-O-methyl embelin were the suitable cross-linkers for both Type I and Type III collagen and stabilizes the collagen at the expected level.</p

Anther culture response in indica rice and variations in major agronomic characters among the androclones of a scented cultivar, Karnal local

Positive selection deems to be improvising those characters. The frequency distribution for number of panicles per plant and panicle length varied largely among the androclones in both direction of the parental mean. Whereas, all the androclones were found to be shorter than the parent and low yielder too. This study elucidates that the genetic modulation through exploitation of androclonal variation is a feasible proposition in scented indica rice

Rapid and recurrent <i style="">in vitro </i>mass-multiplication of androgenic rice embryos

239-242In vitro mass multiplication of plantlets of androgenic origin was achieved in an indica rice var. IR72. The multiple shoots were developed profusely on MS medium containing 4 mg L-1 Kn. When the shoots were cultured on MS supplemented with 6 mg L-1 BAP, a large number of dormant embryos, pro-embryos and embryo-like structures were produced. Those multiple shoots and dormant embryos had no roots. The subcultured shoots and the dormant embryos on MS basal developed into healthy plantlets with prolific roots. Since 1998, these dormant embryos and the shoots are being sub-cultured at 45 d interval. Till date the multiple shoots and the dormant embryos are developing constantly depending upon the hormones used in the medium. The stock is being maintained by recurrent subculture using explants from the preceding culture. Such stock offers ample scope in genetic transformation of indica rice and multiplication of transgenic plantlets. The protocol also prospects efficient in vitro conservation through repeated subculture. It provides a novel source too for constant supply of embryos to produce synthetic seeds of androgenic origin in rice

Development of synthetic seeds involving androgenic and pro-embryos in elite indica rice

515-519Synthetic seeds were produced from anther-derived mass-multiplied embryos and pro-embryos of rice (Oryza sativa L.) var. IR 72. A high dose (4-6 mg L⁻¹) of BAP was found to produce a large number of dormant embryos, pro-embryos and embryo-like structures in about 45 d. These were encapsulated in sodium alginate (2.5% w/v) matrix. Germination and plantlet regeneration capacity of the encapsulated seeds were tested by culturing them on MS fortified with different combinations and concentrations of BAP, Kn and NAA. The result indicated that BAP in combination with lower concentrations of NAA increased germination of beaded embryos over control (MS without hormones). High percent of germination (55-87.5%) was observed when MS was supplemented with BAP and lower concentration of NAA; whereas, addition of Kn in MS reduced the germination percentage. The germination of unbeaded pro-embryos was 92.5% on MS basal medium. The reduced rate of germination of artificial seeds may be attributed to the damage incurred while separating the embryos from clusters and/or owing to adverse effects of chemicals used for encapsulation. Moderate germination (40.0%) was seen on sterile sand. Synthetic seeds may be used for in vitro propagation as well as genetic transformation experiments, especially involving biolistics

The interaction of sodium dodecyl sulfate and urea with cat-fish collagen solutions in acetate buffer: hydrodynamic and thermodynamic studies

Cat-fish collagen was extracted and characterized. Shrinkage temperature of cat-fish collagen is 54.5&#176;C. SDS-PAGE pattern indicated that the cat-fish collagen is Type I in nature. The ratio of proline and hydroxyproline is 1:2 and it suggests cat-fish collagen is vertebrate. The molecular weight of cat-fish collagen was determined by using molecular sieve chromatography and it was found to be 3 20 000 Da. The mutual interaction of cat-fish collagen with SDS and urea was studied at various temperatures. The results suggest that the aggregation of collagen is facilitated by the presence of SDS, whereas hindered by urea. The various thermodynamic parameters were estimated from viscosity measurements and the transfer of collagen into SDS micelles, urea and the reverse phenomenon was analysed. These transfer properties are temperature-dependent. Our thermodynamic results are also able to predict the exact denaturation temperature as well as the structural order of water in the collagen in various environments. The hydrated volumes, Vh of collagen in buffer, SDS, and urea environments using Simha-Einstein equation and intrinsic viscosity were also calculated. The low intrinsic viscosity [&#951;] and high Vh value of collagen in an SDS environment compared to buffer and other environments suggested a more workable system in cosmetic and dermatological preparations. The one and two-hydrogen-bonded models of this collagen in various environments have been analysed. The calculated thermodynamic parameters varied with the concentration of collagen as well as concentration of additives. The change of thermodyanamic parameters from coiled-coil to random-coil conformation upon denaturation of collagen were calculated from the amount of proline and hydroxyproline residues and compared with viscometric results. Denaturation enthalpy of the catfish collagen in buffer, SDS and urea environments has also been determined by differential scanning calorimetric (DSC) measurements, and the results are in good agreement with the viscosity-derived values. The assymmetry and molecular geometry of this collagen in buffer, SDS and urea environments are also computed. Overall, our hydrodynamic and thermodynamic results suggest that the stability of the collagen in the additive environments is in the following order: SDS &#62; buffer &#62; urea