DYNAMICS OF ABSORPTION OF SOME BIOGENIC SALTS IN MODIFIED SALINE MEDIUM

The measuring of Ca2+, Mg2+, K+ has been carried out. This quantity determination had two purposes. It allows us, on the one hand, to show that the assimilation rate of the studied mineral elements and the synthesis of the dry matter are in relation with the composition of the plant organs. On the other hand, to analyse the Na+/ NH4 + antagonism in constantly keeping the concentration of each anion and cation. Within the adjusted saline water T1C, T2C, T3C changing the proportion of NH4 + from 15% to 25% in the total mineral nitrogen of the modified saline solution T1 mod, T2mod, T3, mod. At the level of the two studied species, tomato and bean, the K+ is very abundant with regard to the cations Ca2+, Mg2+, and Na+ probably due to the weak capacity of the cationic root exchange of these plants. The roots of the tomato plants are less loaded with Na+ than the aerial parts. However, the bean stores much more Na+ at the level of the roots, which migrate with difficulty to the aerial parts [2]

DYNAMICS OF ABSORPTION OF SOME BIOGENICS SALTS AT TOMATO AND BEAN PLANT CULTIVATED IN SALINE MEDIUM

The study carried out on the mineral assimilation in saline environment by tomato and bean cultures allowed us to distinguish through the various studied stages, a specifi c assimilation of the mineral element Ca, Mg, K, Na. This study aimed at looking at how assimilation rate of the studied mineral element. The dry matter is in relation with the mineral composition of the plant organs

The prognostic value of four interleukin-1 gene polymorphisms in caucasian women with breast cancer – a multicenter study

<p>Abstract</p> <p>Background</p> <p>The proinflammatory cytokine interleukin-1 (IL-1) is known to play an important role in the carcinogenesis of breast cancer. Although IL-1 gene polymorphisms were reported to be associated with increased risk of breast cancer, their influence on survival of Caucasian breast cancer patients remains to be shown.</p> <p>Methods</p> <p>We studied the influence of four common gene polymorphisms (<it>IL1A </it>-889C/T, <it>IL1B </it>-511C/T, <it>IL1B </it>+3953E1/E2, and <it>IL1RN </it>long/2) of the IL-1 family on survival in 262 Caucasian patients with breast cancer by univariate and multivariate survival analysis. The combined effect of the four gene polymorphisms on overall survival was studied by haplotype analysis.</p> <p>Results</p> <p>In the present study 38 cases of cancer related death and a median time of follow-up (range) of 55.3 (0.4–175.8) months was observed. <it>IL1RN </it>2/2 (homozygous mutant) gene polymorphism was associated with shortened disease free and overall survival in a univariate (p = 0.001 and p = 0.01, respectively) and multivariate analysis (p = 0.002, Odds Ratio [95% Confidence Interval] = 3.6 [1.6–8.0] and p = 0.05, Odds Ratio = 3.0 [1.1–9.3], respectively). Presence of the homozygous mutant genotype of the <it>IL1A </it>-889 and <it>IL1B </it>+3953 gene polymorphism was associated with overall survival in the univariate (p = 0.004 and p = 0.002, respectively), but not in the multivariate analysis. No association was observed between all possible haplotype combinations and overall survival.</p> <p>Conclusion</p> <p>Carriage of the mutant alleles of <it>IL1RN </it>was independently associated with shortened disease free and overall survival rates in Caucasian patients with breast cancer.</p

The poly dA helix: a new structural motif for high performance DNA-based molecular switches

We report a pH-dependent conformational transition in short, defined homopolymeric deoxyadenosines (dA15) from a single helical structure with stacked nucleobases at neutral pH to a double-helical, parallel-stranded duplex held together by AH+-H+A base pairs at acidic pH. Using native PAGE, 2D NMR, circular dichroism (CD) and fluorescence spectroscopy, we have characterized the two different pH dependent forms of dA15. The pH-triggered transition between the two defined helical forms of dA15 is characterized by CD and fluorescence. The kinetics of this conformational switch is found to occur on a millisecond time scale. This robust, highly reversible, pH-induced transition between the two well-defined structured states of dA15 represents a new molecular building block for the construction of quick-response, pH-switchable architectures in structural DNA nanotechnology

Molecular insights into Coumarin analogues as antimicrobial agents: Recent developments in drug discovery

A major global health risk has been witnessed with the development of drug-resistant bacteria and multidrug-resistant pathogens linked to significant mortality. Coumarins are heterocyclic compounds belonging to the benzophenone class enriched in different plants. Coumarins and their derivatives have a wide range of biological activity, including antibacterial, anticoagulant, antioxidant, anti-inflammatory, antiviral, antitumour, and enzyme inhibitory effects. In the past few years, attempts have been reported towards the optimization, synthesis, and evaluation of novel coumarin analogues as antimicrobial agents. Several coumarin-based antibiotic hybrids have been developed, and the majority of them were reported to exhibit potential antibacterial effects. In the present work, studies reported from 2016 to 2020 about antimicrobial coumarin analogues are the focus. The diverse biological spectrum of coumarins can be attributed to their free radical scavenging abilities. In addition to various synthetic strategies developed, some of the structural features include a heterocyclic ring with electron-withdrawing/donating groups conjugated with the coumarin nucleus. The suggested structure−activity relationship (SAR) can provide insight into how coumarin hybrids can be rationally improved against multidrug-resistant bacteria. The present work demonstrates molecular insights for coumarin derivatives having antimicrobial properties from the recent past. The detailed SAR outcomes will benefit towards leading optimization during the discovery and development of novel antimicrobial therapeutics

Mathematical analysis of the Escherichia coli chemotaxis signalling pathway

We undertake a detailed mathematical analysis of a recent nonlinear ordinary differential equation (ODE) model describing the chemotactic signalling cascade within an {\it Escherichia coli} cell. The model includes a detailed description of the cell signalling cascade and an average approximation of the receptor activity. A steady-state stability analysis reveals the system exhibits one positive real steady-state which is shown to be asymptotically stable. Given the occurrence of a negative feedback between phosphorylated CheB (CheB-P) and the receptor state, we ask under what conditions, the system may exhibit oscillatory type behaviour. A detailed analysis of parameter space reveals that whilst variation in kinetic rate parameters within known biological limits is unlikely to lead to such behaviour, changes in the total concentration of the signalling proteins does. We postulate that experimentally observed overshoot behaviour can actually be described by damped oscillatory dynamics and consider the relationship between overshoot amplitude, total cell protein concentration and the magnitude of the external ligand stimulus. Model reductions of the full ODE model allow us to understand the link between phosphorylation events and the negative feedback between CheB-P and receptor methylation, as well as elucidate why some mathematical models exhibit overshoot and others do not. Our manuscript closes by discussing intercell variability of total protein concentration as means of ensuring the overall survival of a population as cells are subjected to different environments