Plant delta(15)N associated with arbuscular mycorrhization, drought and nitrogen deficiency

It has long been evident that plant (15)N chiefly reflects the processes which fractionate (15)N/(14)N rather than the (15)N of plant N source(s). It has emerged recently that one of the most important fractionating processes contributing to the whole plant (15)N is the presence/absence, type or species of mycorrhiza, especially when interacting with nutrient deficiency. Ecto- and ericoid mycorrhizas are frequently associated with (15)N-depleted foliar (15)N, commonly as low as -12 per thousand. As shown by the present study, plants having no mycorrhiza, or those infected with various species of arbuscular mycorrhiza (AM)-forming fungi, interact with varying concentrations of soil nitrogen [N] and moisture to enrich plant (15)N by as much as 3.5 per thousand. Hence the lack of a mycorrhiza, or variation in the species of AM-forming fungal associations, can account for about 25% of the usually reported variations of foliar (15)N found in field situations and do so by (15)N enrichment rather than depletion. Copyright 1999 John Wiley & Sons, Ltd.     

Modelling capillary filling dynamics using lattice Boltzmann simulations

We investigate the dynamics of capillary filling using two lattice Boltzmann schemes: a liquid-gas model and a binary model. The simulation results are compared to the well-known Washburn's law, which predicts that the filled length of the capillary scales with time as l ∝ t ^1/2. We find that the liquid-gas model does not reproduce Washburn's law due to condensation of the gas phase at the interface, which causes the asymptotic behaviour of the capillary penetration to be faster than t ^1/2. The binary model, on the other hand, captures the correct scaling behaviour when the viscosity ratio between the two phases is sufficiently high.     

Age-related waning of in vitro Interferon-γ levels against r32kDaBCG in BCG vaccinated children

Background  

Mycobacterium bovis BCG vaccine has displayed inconsistent efficacy in different trials conducted in various geographical regions. Nevertheless, it significantly reduces the risk of severe childhood tuberculosis and continues to be used to prevent tuberculosis in many countries. Many studies revealed that efficacy of vaccine wanes with age. Most of the studies were based on in vivo and in vitro responses to tuberculin. With the advent of newer tests such as in vitro interferon-γ assays and identification of potent immunogenic mycobacterial proteins there is a need to corroborate the observations. This study aims at ascertaining the need for a booster at a later age as indicated by in vitro release of IFN-γ while evaluating Ag85A as an antigen.     

Synthesis and Biological Activity of New Resveratrol Derivative and Molecular Docking: Dynamics Studies on NFkB

Resveratrol (RVS) is a naturally occurring antioxidant, able to display an array of biological activities. In the present investigation, a new derivative of RVS, RVS(a), was synthesized, and its biological activity was determined on U937 cells. It was observed that RVS(a) showed pronounced activity on U937 cells than RVS. RVS(a) is able to induce apoptosis in tumor cell lines through subsequent DNA fragmentation. From the EMSA results, it was evident that RVS(a) was able to suppress the activity of NFkB by interfering its DNA binding ability. Furthermore, the molecular interaction analysis (docking and dynamics) stated that RVS(a) has strong association with the IkB-alpha site of NFkB compared with RVS; this binding nature of RVS(a) might be prevent the NFkB binding ability with DNA. The present findings represent the potential activity of propynyl RVS on U937 cells and signifying it as a one of putative chemotherapeutic drugs against cancer.     

Neuropeptide delivery to the brain: a von Willebrand factor signal peptide to direct neuropeptide secretion

Background  

Multiple neuropeptides, sometimes with opposing functions, can be produced from one precursor gene. To study the roles of the different neuropeptides encoded by one large precursor we developed a method to overexpress minigenes and establish local secretion.     

Poly(N‐acetyl‐α‐acrylic acid): Synthesis,Characterization and Chelation Properties through Liquid Phase Polymer‐Based Retention Technique

The synthesis and characterization of the water‐soluble poly(N‐acetyl‐α‐acrylic acid) by radical polymerization were carried out. The polymer was characterized by Fourier Transform Infrared (FT‐IR), ¹H NMR and ¹³C NMR spectroscopies, and thermogravimetric analysis (TGA). The metal ion binding properties for the metals Cu(II), Co(II), Ni(II), Cd(II), Zn(II), Pb(II), Hg(II), Cr(III) in the aqueous phase were studied using the liquid‐phase polymer‐based retention technique. The metal ion interactions with the hydrophilic polymer were determined as a function of pH and of the filtration factor. The polychelatogen showed a high affinity for metal ions and higher selectivity for Cr(III) at pH = 3.     

Chelating properties of poly(N‐acryloyl piperazine) by liquid‐phase polymer‐based retention (LPR) technique

The synthesis of poly(N‐acryloylpiperazine) was carried out by radical polymerization giving a yield of 90%. The polymer was soluble in water and was characterized by FTIR, ¹H NMR, ¹³C NMR spectroscopy, and TGA. The metal ability binding properties for the Ag(I), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Pb(II), and Cr(III) metal ions in the aqueous phase were investigated using the liquid‐phase polymer‐based retention (LPR) method. The metal ion interactions with the hydrophilic polymers were determined as a function of pH and filtration factor.