Nanoscale Diblock Copolymer Micelles: Characterizations and Estimation of the Effective Diffusion Coefficients of Biomolecules Release through Cylindrical Diffusion Model

Biomolecules have been widely investigated as potential therapeutics for various diseases. However their use is limited due to rapid degradation and poor cellular uptake in vitro and in vivo. To address this issue, we synthesized a new nano-carrier system comprising of cholic acid-polyethylenimine (CA-PEI) copolymer micelles, via carbodiimide-mediated coupling for the efficient delivery of small interfering ribonucleic acid (siRNA) and bovine serum albumin (BSA) as model protein. The mean particle size of siRNA- or BSA-loaded CA-PEI micelles ranged from 100–150 nm, with zeta potentials of +3-+11 mV, respectively. Atomic force, transmission electron and field emission scanning electron microscopy demonstrated that the micelles exhibited excellent spherical morphology. No significant morphology or size changes were observed in the CA-PEI micelles after siRNA and BSA loading. CA-PEI micelles exhibited sustained release profile, the effective diffusion coefficients were successfully estimated using a mathematically-derived cylindrical diffusion model and the release data of siRNA and BSA closely fitted into this model. High siRNA and BSA binding and loading efficiencies (95% and 70%, respectively) were observed for CA-PEI micelles. Stability studies demonstrated that siRNA and BSA integrity was maintained after loading and release. The CA-PEI micelles were non cytotoxic to V79 and DLD-1 cells, as shown by alamarBlue and LIVE/DEAD cell viability assays. RT-PCR study revealed that siRNA-loaded CA-PEI micelles suppressed the mRNA for ABCB1 gene. These results revealed the promising potential of CA-PEI micelles as a stable, safe, and versatile nano-carrier for siRNA and the model protein delivery.     

Effects of nickel toxicity on morphological and physiological aspects of osmoregulation in <Emphasis Type="Italic">Typha domingensis</Emphasis> (<Emphasis Type="Italic">Typhaceae</Emphasis>) populations

The present work examined morphological and physiological aspects of osmoregulation in some differently adapted populations of Typha domingensis. Six populations of T. domingensis were grown in waterlogged conditions under four levels of nickel (0, 50, 100 and 1500 mg/kg of Ni). The Ni tolerance was explored on the basis of different characteristics of shoots. Along with the increasing level of Ni stress, all populations showed an increment of proline and glycinebetaine content, low photosynthetic and transpiration rates and decreased chlorophyll content. Analyzed morphological parameters revealed possible adaptations to deal with Ni stress. The less tolerant Sahianwala population produced more aerenchyma, less accumulation of osmolytes and reduced shoot fresh weight under Ni stress than the tolerant ones. Our results suggested that T. domingensis has the capacity to survive under Ni stress and could be used for the absorption of toxic metal ions from industrially polluted water.     

Characterization of Asymmetric Tapered Dipole Nanoantenna for Energy Harvesting Applications

In this paper, systematic study for asymmetric tapered dipole nanoantenna is implemented using finite element frequency domain (FEFD) solver where harvesting efficiency, field confinement, surface current, and input impedance are calculated at wavelength of 500 nm. The proposed nanoantennas achieve a harvesting efficiency of 61.3% and a field enhancement factor of 37.7 over the conventional dipole nanoantenna. This enhancement is attributed to the irregularity of the surface current distribution on the asymmetric designs. Particle swarm optimization technique is used to find the optimum design geometrical parameters through an external link between the optimization algorithm and the FEFD solver. Moreover, the proposed designs offer a resonance impedance of 500 Ω to match that of fabricated rectifiers. Further study of the structure fabrication tolerance is included which shows the robustness of the proposed nanoantennas.     

Role of Zinc–Lysine on Growth and Chromium Uptake in Rice Plants under Cr Stress

Journal of Plant Growth Regulation - Chromium (Cr) is a very toxic heavy metal present in agricultural soils. Soils contaminated with Cr are the major source of Cr entrance into the food chain. The...     

Effect of soil solarization on corn stalk rot

Seven weeks solarization of irrigated soil raised its temperature by 11.5°C over non-solarized soil at 10 cm depth and effectively controlled weeds (98.5%), stalk borer (8.9%) and stalk rot disease (69.1%) in corn. Solarization also reduced symptoms of Fusarium moniliforme and Macrophomina phaseolina significantly by 64.2% and 78.4%, respectively, and completely controlled M. phaseolina in corn cultivars, viz. Pool-10, Shaheen and Gauher. Whereas symptoms of F. moniliforme were observed in these cultivars, Fusarium graminearum was not observed except in two cultivars, Shaheen and Akbar. Growth of crop planted in solarized plots was better and it yielded almost one to three times more grains in cultivars under test. Soil analysis immediately following solarization revealed that essential elements were readily available in simpler forms, which may have increased pest resistance and reduced stalk breakage.     

A study on distribution of natural radionuclide polonium-210 in a pond ecosystem

This paper presents the results of an investigation on the distribution of²¹⁰Po in Mutharasanallur pond ecosystem. It has been demonstrated that²¹⁰Po is non-uniformly distributed within the ecosystem. The results of the study show a dissolved²¹⁰Po concentration in pond water of 1 4mBq 1₋₁. The sediment samplso recorded a²¹⁰Po activity of 59 9 Bq kg₋₁. The aquatic organisms showed differential accumulation of the radionuclide with enhanced bioaccumulation in soft tissues and muscle. The²¹⁰Po activity in the biota fell within the range of 1·2–53 3 Bq kg₋₁ (wet wt). The bivalve mussel,Lamellidens marginalis was identified to accumulate higher concentration of²¹⁰Poin soft tissues, suggesting that these organisms could serve as a bio-monitor of²¹⁰Po radionuclide in a freshwater system. The concentration factors of²¹⁰Po for the biotic components ranged from ∼10²–∼10⁴. Analyses of the results indicate that prawn and fish represent an important source of supply of²¹⁰Po to humans via dietary intake. Results of²¹⁰Po activity in the abiotic and biotic components of the pond ecosystem were higher when compared with those of Cauvery river system, the primary water source of the pond.     

Production of alkaline protease by a new Bacillus subtilis isolate for use as a bating enzyme in leather treatment

Bacillus subtilis, isolated from tannery waste, produced an alkaline protease at optimal activity when grown in a casein/gelatine medium in a stirred tank fermenter at 37°C with the dissolved oxygen tension at 40% air saturation. Optimum protease activity (223 U ml^-1) was at pH 8.5 and was stable for 1 h up to 45°C but at 60°C lost 80% activity. Use of the crude protease as a bating agent for producing high quality leather is indicated. Tensile strength, bursting strength, tear strength and elongation at break of prepared leather were increased with increasing amounts of protease used for bating.A. Hameed and M.A. Natt are with the Department of Biological Sciences, Quaid-i-Azam University, Islamabad. Pakistan. C.S. Evans is with the School of Biological and Health Sciences, University of Westminster, London. UK.     

SSR based genetic diversity of pigmented and aromatic rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) genotypes of the western Himalayan region of India

A set of 24 of SSR markers were used to estimate the genetic diversity in 16 rice genotypes found in Western Himalayas of Kashmir and Himachal Pradesh, India. The level of polymorphism among the genotypes of rice was evaluated from the number of alleles and PIC value for each of the 24 SSR loci. A total of 68 alleles were detected across the 16 genotypes through the use of these 24 SSR markers The number of alleles per locus generated varied from 2 (RM 338, RM 452, RM 171) to 6 (RM 585, RM 249, RM 481, RM 162). The PIC values varied from 0.36 (RM 1) to 0.86 (RM 249) with an average of 0.62 per locus. Based on information generated, the genotypes got separated in six different clusters. Cluster 1 comprised of 4 genotypes viz; Zag 1, Zag 13, Pusa sugandh 3, and Zag 14, separated from each other at a similarity value of 0.40. Cluster second comprised of 3 landraces viz; Zag 2. Zag 4 and Zag10 separated from each other at a similarity value of 0.45. Cluster third comprised of 3 genotypes viz; Grey rice, Mushk budji and Kamad separated from each other at a similarity value of 0.46. Cluster fourth had 2 landraces viz; Kawa kreed and Loual anzul, and was not sub clustered. Fifth cluster had 3 genotypes viz; Zag 12, Purple rice and Jhelum separated from each other at a similarity value of 0.28. Cluster 6 comprised of a single popular variety i.e. Shalimar rice 1 with independent lineage.