Solvophobic and solvophilic contributions in the water-to-aqueous guanidinium chloride transfer free energy of model peptides

We study the solvation free energy of two different conformations (helix and extended) of two different peptides (deca-alanine and deca-glycine) in two different solvents (water and aqueous guanidinium chloride, GdmCl). The free energies are obtained using the quasichemical organization of the potential distribution theorem, an approach that naturally provides the repulsive (solvophobic or cavity) and attractive (solvophilic) contributions to solvation. The solvophilic contribution is further parsed into a chemistry contribution arising from solute interaction with the solvent in the first solvation shell and a long-range contribution arising from non-specific interactions between the solute and the solvent beyond the first solvation shell. The cavity contribution is obtained for two different envelopes, $\Sigma_{SE}$ which theory identifies as the solvent excluded volume and a larger envelope ($\Sigma_G$) beyond which solute-solvent interactions are Gaussian. For both envelopes, the cavity contribution in water is proportional to the surface area of the envelope. The same does not hold for GdmCl(aq), revealing limitations of using molecular area to assess solvation energetics, especially in mixed solvents. The $\Sigma_G$-cavity contribution predicts that GdmCl(aq) should favor the more compact state, contrary to the role of GdmCl in unfolding proteins. The chemistry contribution attenuates this effect, but still the net local (chemistry plus $\Sigma_G$-packing) contribution is inadequate in capturing the role of GdmCl. With the inclusion of the long-range contribution, which is dominated by van~der~Waals interaction, aqueous GdmCl favors the extended conformation over the compact conformation. Our finding emphasizes the importance of weak, but attractive, long-range dispersion interactions in protein solution thermodynamics

Symptomatic giant left atrial aneurysm in a child : a rare entity

Isolated left atrial aneurysms are rare entities in clinical practice. Usually the condition is diagnosed in the second to fourth decades of life. The presence of such lesions in the pediatric age group is scantily described. We present a 2 year boy who presented with complaints of excessive irritability, respiratory distress and swelling of the feet. On examination, child was tachypnoeic with irregularly irregular rhythm. Echo showed a huge aneurysmal LA appendage with severe left ventricle dysfunction. The child underwent surgical resection for same. Findings were confirmed intraoperatively but he continued to have low cardiac output state after the surgery, with frequent arrhythmias and expired on day 7 of surgery. The case is reviewed and compared with the available English literature.peer-reviewe

A Posteriori Error Estimates for Nonconforming Approximations of Evolutionary Convection-Diffusion Problems

We derive computable upper bounds for the difference between an exact solution of the evolutionary convection-diffusion problem and an approximation of this solution. The estimates are obtained by certain transformations of the integral identity that defines the generalized solution. These estimates depend on neither special properties of the exact solution nor its approximation, and involve only global constants coming from embedding inequalities. The estimates are first derived for functions in the corresponding energy space, and then possible extensions to classes of piecewise continuous approximations are discussed.Comment: 10 page

Effect of hydropriming and different sowing dates on growth and yield attributes of Wheat (Triticum aestivum L.)

The present investigation was conducted to study the effects of hydropriming and different sowing dates on growth and yield attributes of wheat (Triticum aestivum L.) during Rabi season of 2014-15.The experiment was conducted in Randomised Block Design with three replications. The highest germination percentage was recorded at T4 [hydropriming] 22nd Nov + 16 hrs. ( 94.04%), plant height highest was recorded at T4 (95.23cm), highest number of tillers at T4 (4.40), number of spikelet per spike highest at T4 (18.73), numbers of grains per spike highest at T4 (53.13), root length (16.07cm), test weight (43.33g), grain yield (42.79 q/ha), harvest index (63.46%) recorded similar result in same treatment. Therefore it may be concluded that 22nd Nov with 16 hrs. of hydropriming treatment can be recommended to PBW-343 wheat grower for obtaining better growth and yield