Stability of binary complexes of Pb(II), Cd(II) and Hg(II) with maleic acid in TX100-water mixtures

Binary complexes of maleic acid with toxic metal ions such as Pb(II), Cd(II) and Hg(II) have been studied in 0.0-2.5% v/v tritonX-100 (TX100) - water media at 303 K  at an ionic strength of 0.16 M. The active forms of the ligand are LH2, LH- and L2-. The derived ‘best fit’ chemical speciation models are based on crystallographic R-factors, χ2 and Skewness and Kurtosis factors. The predominant species formed are of the type ML2, ML2H and ML3. The trend in variation of complex stability constants with change in the mole fraction of the medium is explained on the basis of prevailing electrostatic and non-electrostatic forces. The species distribution as a function of pH at different compositions of TX100-water mixtures and plausible speciation equilibria are presented and discussed. KEY WORDS: Maleic acid, TritonX-100, Toxic metal ions, Mole fraction, Binary complexes Bull. Chem. Soc. Ethiop. 2014, 28(3), 383-391.DOI: http://dx.doi.org/10.4314/bcse.v28i3.

Classification of Solutions of Non-homogeneous Non-linear Second Order Neutral Delay Dynamic Equations with Positive and Negative Coefficients

In this paper we have studied the non-homogeneous non-linear second order neutral delay dynamic equations with positive and negative coefficients of the form classified all solutions of this type equations and obtained conditions for the existence or non-existence of solutions into four classes and these four classes are mutually disjoint. Examples are included to illustrate the validation of the main results

COST BENEFIT ANALYSIS OF A DG INTEGRATED SYSTEM: CASE STUDY

Distributed Generation is capable of meeting the load of the consumers partially or completely. Depending on the type of DG involved it can be operated in interconnected mode and islanded mode. The availability of numerous alternatives present for the DG technologies and large initial investments necessitates a detailed cost benefit analysis for the implementation of DG technologies. In this work an attempt has been made to study the costs involved in implementing the DG technologies. A practical system having two kinds of distributed generation i.e., Diesel Generator and solar photovoltaic system for its back up purpose is considered. A detailed cost analysis of the two DG technologies is carried out

DEVELOPMENT OF OSMOTICALLY CONTROLLED ORAL DRUG DELIVERY SYSTEM FOR NATEGLINIDE AN ANTI-DIABETIC DRUG

Objective: The purpose of the present study was to develop an oral push-pull osmotic drug delivery system for the drug Nateglinide which is a bio pharmaceutics classification system (BCS) class II drug. Methods: The tablets were prepared by the wet granulation method using ingredients microcrystalline cellulose (Adsorbent), potassium chloride (Osmotic agent), poly ethylene glycol (4000 and 6000) (Hydrophilic polymer, Plasticizer), starch (Disintegrant), and aerosil. The granules were compacted by double compression method and were coated with eudragit by dipping method. Different batches were prepared to study the effect of the various ingredients and their effect on the release of the drug from the system by varying the concentrations of the ingredients in each batch. Dissolution was assessed using USP dissolution apparatus 2 in phosphate buffer pH 6.8 for 12 h. Results: Certain key findings observed includes a decrease in micro crystalline cellulose content reduced the release of the drug due to the reduction of the hydrophilic content in the tablet which complements the uptake of water from the surroundings, and increase in the ethylene glycol leads to decrease in the release which resulted due to excess swelling and increase in the osmotic agent concentration lead to satisfactory release of the drug and followed zero-order release. Conclusion: To conclude, the push-pull osmotic tablet of Nateglinide was able to deliver the drug in a controlled pattern for a prolonged period of time. This type of formulation can be used in conditions like hyperglycemia where the patient compliance can improve by reducing the dosing frequency and the plasma drug levels can be maintained, the total drug load is also reduced so that the dose related side-effects are also reduced. Keywords: Controlled release, Push-pull osmotic pump, Nateglinid

Characterization of protective epitopes in a highly conserved Plasmodium falciparum antigenic protein containing repeats of acidic and basic residues

The delineation of putatively protective and immunogenic epitopes in vaccine candidate proteins constitutes a major research effort towards the development of an effective malaria vaccine. By virtue of its role in the formation of the immune clusters of merozoites, its location on the surface of merozoites, and its highly conserved nature both at the nucleotide sequence level and the amino acid sequence level, the antigen which contains repeats of acidic and basic residues (ABRA) of the human malaria parasite Plasmodium falciparum represents such an antigen. Based upon the predicted amino acid sequence of ABRA, we synthesized eight peptides, with six of these (AB-1 to AB-6) ranging from 12 to 18 residues covering the most hydrophilic regions of the protein, and two more peptides (AB-7 and AB-8) representing its repetitive sequences. We found that all eight constructs bound an appreciable amount of antibody in sera from a large proportion of P. falciparum malaria patients; two of these peptides (AB-1 and AB-3) also elicited a strong proliferation response in peripheral blood mononuclear cells from all 11 human subjects recovering from malaria. When used as carrier-free immunogens, six peptides induced a strong, boostable, immunoglobulin G-type antibody response in rabbits, indicating the presence of both B-cell determinants and T-helper-cell epitopes in these six constructs. These antibodies specifically cross-reacted with the parasite protein(s) in an immunoblot and in an immunofluorescence assay. In another immunoblot, rabbit antipeptide sera also recognized recombinant fragments of ABRA expressed in bacteria. More significantly, rabbit antibodies against two constructs (AB-1 and AB-5) inhibited the merozoite reinvasion of human erythrocytes in vitro up to ∼90%. These results favor further studies so as to determine possible inclusion of these two constructs in a multicomponent subunit vaccine against asexual blood stages of P. falciparum

Size--sensitive melting characteristics of gallium clusters: Comparison of Experiment and Theory for Ga17+_{17}{}^{+} and Ga20+_{20}{}^{+}

Experiments and simulations have been performed to examine the finite-temperature behavior of Ga$_{17}{}^{+}$ and Ga$_{20}{}^{+}$ clusters. Specific heats and average collision cross sections have been measured as a function of temperature, and the results compared to simulations performed using first principles Density--Functional Molecular--Dynamics. The experimental results show that while Ga$_{17}{}^{+}$ apparently undergoes a solid--liquid transition without a significant peak in the specific--heat, Ga$_{20}{}^{+}$ melts with a relatively sharp peak. Our analysis of the computational results indicate a strong correlation between the ground--state geometry and the finite--temperature behavior of the cluster. If the ground--state geometry is symmetric and "ordered" the cluster is found to have a distinct peak in the specific--heat. However, if the ground--state geometry is amorphous or "disordered" the cluster melts without a peak in the specific--heat.Comment: 6 figure

Expression Analysis of Novel microRNAs in Rice During High Temperature Stress

MicroRNAs (miRNAs) are small non-coding RNAs which play an important role in regulating the genes involved in plant growth and development. Several studies showed that miRNAs are involved in plants response to different kinds of abiotic stresses also. In our previous study, temperature responsive miRNAs were predicted in O.sativa. 27 miRNAs were predicted to be novel in rice using homology search. In continuation to our previous study, expression of 14 novel miRNAs was done in shoot and root of 13 days old seedlings of five different rice cultivars using real time PCR. Expression these miRNAs was analyzed in control and high temperature stress environment. Out of 14 predicted novel miRNAs, two novel miRNAs- miR157a and miR165a showed expression in all five rice cultivars. Interestingly, miR165a showed a differential expression pattern among heat tolerant (N22, IR64 and Rasi) and susceptible (Vandana and Sampada) cultivars suggesting that it might have specific role in high temperature tolerance

A multi-dimensional approach from seed-to-seed to understand and improve heat stress tolerance in rice

In changing climatic conditions, stress caused by high temperature poses a serious threat to rice cultivation. Physiological, biochemical, and molecular analysis of rice cultivars revealed that Nagina22 (N22) shows lesser reduction in chlorophyll content, net photosynthetic rate, spikelet fertility and grain yield, but increased membrane thermal stability, antioxidant enzymes activity and transpiration rate (E) at high temperature. DREB, RAB, LEA, and genes associated with hormones signalling were induced during germination, while OsFd (an iron sulphur cluster binding protein) and CWIP (cell wall integrity protein) emerged as high priority candidate genes in seedling and reproductive stages. Their function is being analysed by transgene expression and CRISPR/Cas genome editing approaches. Field screening in polyhouse, late sowing and temperature gradient chamber for 20 morpho-physiological traits indicated the importance of both yield and spikelet fertility, and photosynthesis traits. N22 showed the least Heat Susceptibility Index (HSI) for yield/plant, spikelet fertility, flag leaf SPAD and stomatal conductance, while Vandana showed the highest HSI for spikelet fertility and flag leaf temperature. QTLs for HSI of spikelet fertility were identified on chromosome 1 and HSI of yield per plant on chromosomes 1, 2, 3, 4, 7 and 8; and PV of 6% to 57% using 174 F2-3 Vandana x N22 mapping population. Simultaneously, RNAseq was performed to identify the genome wide miRNAs and transcriptome of N22 and Vandana from shoot and root after short and long duration of heat stress treatments; and recovery phase for an eQTL-guided function-related co-expression analysis to identify the putative regulators and gene regulatory networks

Deep sequencing of small RNAs reveals ribosomal origin of microRNAs in Oryza sativa and their regulatory role in high temperature

MicroRNAs are small noncoding regulatory RNAs which control gene expression by mRNA degradation or translational repression. They are significant molecular players regulating important biological processes such as developmental timing and stress response. We report here the discovery of miRNAs derived from ribosomal DNA using the small RNA datasets of 16 deep sequencing libraries of rice. Twelve putative miRNAs were identified based on highly stringent criteria of novel miRNA prediction. Surprisingly, 10 putative miRNAs (mi_7403, mi_8435, mi_12675, mi_4266, mi_4758, mi_4218, mi_8200, mi_4644, mi_14291, mi_16235) originated from rDNA of rice chromosome 9. Expression analysis of putative miRNAs and their target genes in heat tolerant and susceptible rice cultivars in control and high temperature treated seedlings revealed differential regulation of rDNA derived miRNAs. This is the first report of rDNA derived miRNAs in rice which indicates their role in gene regulation during high temperature stress in plants. Further studies in this area will open new research challenges and opportunities to broaden our knowledge on gene regulation mechanisms