DEVELOPMENT OF A MODIFIER FOR GIVING MATERIALS FROM EFFICIENTLY PROCESSED WOOD BIOMASS SPECIAL PROPERTIES

Background. Wood is a unique material in its structure. However, materials made from wood raw materials have such negative properties as insufficient bio- and fire-resistance. In turn, when organizing and improving the efficiency of logging activity, large amounts of practically unused cutting residues is produced. Their modification for the purposes of the forest industry is an effective tool for creating many valuable and demanded products. In particular, arilazo-β-dicarbonyl compounds are widely used as syntons for the production of heterocyclic compounds. Among heterocycles, a large number of compounds have found application in the form of biologically active substances that have been successfully and for a long time used as pesticides for the wood processing industry. Purpose. Synthesis of p-nitrophenyl hydrobutanons, cyclocondensation to form pyrazoles and study of their chemical properties of the substances first obtained. Proof of structure by modern spectral analysis methods. Materials and Methods. Research methods include: organic synthesis; UV spectrometry, 1H NMR, 13H NMR. Results. Four new compounds were synthesized: 4-methoxy-1-(p-chloro(bromo)phenyl)-2-(p-nitrophenylhydrazo)-1,2,3-butantrions and 3(5)-methoxy-5(3)-(p-chloro(bromo)phenyl)-4-(p-nitrophenylhydrazo)-1H-pyrazoles. Amines were prepared by the reduction of the related nitrosopyrazoles. The acylation reaction was demonstrated for the obtained amine. The structures of all synthesized compounds were proved by modern methods of analysis. Conclusion. Thus, we synthesized p-nitrophenylhydrazobutanetriones with a chloro(bromo)phenyl substituent, their cyclization products with hydrazine, and N-(5-(4-chloro(bromo)phenyl)-3-(methoxymethyl)-1H-pyrazole-4-yl)acetamides based on them. The structure of the obtained substances was determined by spectral methods of analysis

Reversible and Noisy Progression towards a Commitment Point Enables Adaptable and Reliable Cellular Decision-Making

Cells must make reliable decisions under fluctuating extracellular conditions, but also be flexible enough to adapt to such changes. How cells reconcile these seemingly contradictory requirements through the dynamics of cellular decision-making is poorly understood. To study this issue we quantitatively measured gene expression and protein localization in single cells of the model organism Bacillus subtilis during the progression to spore formation. We found that sporulation proceeded through noisy and reversible steps towards an irreversible, all-or-none commitment point. Specifically, we observed cell-autonomous and spontaneous bursts of gene expression and transient protein localization events during sporulation. Based on these measurements we developed mathematical population models to investigate how the degree of reversibility affects cellular decision-making. In particular, we evaluated the effect of reversibility on the 1) reliability in the progression to sporulation, and 2) adaptability under changing extracellular stress conditions. Results show that reversible progression allows cells to remain responsive to long-term environmental fluctuations. In contrast, the irreversible commitment point supports reliable execution of cell fate choice that is robust against short-term reductions in stress. This combination of opposite dynamic behaviors (reversible and irreversible) thus maximizes both adaptable and reliable decision-making over a broad range of changes in environmental conditions. These results suggest that decision-making systems might employ a general hybrid strategy to cope with unpredictably fluctuating environmental conditions

Reversible and noisy progression towards a commitment point enables adaptable and reliable cellular decision-making

Cells must make reliable decisions under fluctuating extracellular conditions, but also be flexible enough to adapt to such changes. How cells reconcile these seemingly contradictory requirements through the dynamics of cellular decision-making is poorly understood. To study this issue we quantitatively measured gene expression and protein localization in single cells of the model organism Bacillus subtilis during the progression to spore formation. We found that sporulation proceeded through noisy and reversible steps towards an irreversible, all-or-none commitment point. Specifically, we observed cell-autonomous and spontaneous bursts of gene expression and transient protein localization events during sporulation. Based on these measurements we developed mathematical population models to investigate how the degree of reversibility affects cellular decision-making. In particular, we evaluated the effect of reversibility on the 1) reliability in the progression to sporulation, and 2) adaptability under changing extracellular stress conditions. Results show that reversible progression allows cells to remain responsive to long-term environmental fluctuations. In contrast, the irreversible commitment point supports reliable execution of cell fate choice that is robust against short-term reductions in stress. This combination of opposite dynamic behaviors (reversible and irreversible) thus maximizes both adaptable and reliable decision-making over a broad range of changes in environmental conditions. These results suggest that decision-making systems might employ a general hybrid strategy to cope with unpredictably fluctuating environmental conditions.GMS acknowledges support by NIH Grant No. NIGMS RO1 GM088428, Welch Foundation (Grant No. I-1674), and James S. McDonnell Foundation (Grant No. 220020141). JGO acknowledges financial support from the Ministerio de Ciencia e Innovación (Spain, Project No. FIS2009-13360) and the ICREA/nAcademia programme

Slowdown of growth controls cellular differentiation

Abstract How can changes in growth rate affect the regulatory networks behavior and the outcomes of cellular differentiation? We address this question by focusing on starvation response in sporulating Bacillus subtilis. We show that the activity of sporulation master regulator Spo0A increases with decreasing cellular growth rate. Using a mathematical model of the phosphorelay—the network controlling Spo0A—we predict that this increase in Spo0A activity can be explained by the phosphorelay protein accumulation and lengthening of the period between chromosomal replication events caused by growth slowdown. As a result, only cells growing slower than a certain rate reach threshold Spo0A activity necessary for sporulation. This growth threshold model accurately predicts cell fates and explains the distribution of sporulation deferral times. We confirm our predictions experimentally and show that the concentration rather than activity of phosphorelay proteins is affected by the growth slowdown. We conclude that sensing the growth rates enables cells to indirectly detect starvation without the need for evaluating specific stress signals

Temporal competition between differentiation programs determines cell fate choice

Multipotent differentiation, where cells adopt one of several possible fates, occurs in diverse systems ranging from bacteria to mammals. This decision-making process is driven by multiple differentiation programs that operate simultaneously in the cell. How these programs interact to govern cell fate choice is poorly understood. To investigate this issue, we simultaneously measured activities of the competing sporulation and competence programs in single Bacillus subtilis cells. This approach revealed that these competing differentiation programs progress independently without cross-regulation before the decision point. Cells seem to arrive at a fate choice through differences in the relative timing between the two programs. To test this proposed dynamic mechanism, we altered the relative timing by engineering artificial cross-regulation between the sporulation and competence circuits. Results suggest a simple model that does not require a checkpoint or intricate cross-regulation before cellular decision-making. Rather, cell fate choice appears to be the outcome of a 'molecular race' between differentiation programs that compete in time, providing a simple dynamic mechanism for decision-making

Temporal competition between differentiation programs determines cell fate choice

Multipotent differentiation, where cells adopt one of several possible fates, occurs in diverse systems ranging from bacteria to mammals. This decision-making process is driven by multiple differentiation programs that operate simultaneously in the cell. How these programs interact to govern cell fate choice is poorly understood. To investigate this issue, we simultaneously measured activities of the competing sporulation and competence programs in single Bacillus subtilis cells. This approach revealed that these competing differentiation programs progress independently without cross-regulation before the decision point. Cells seem to arrive at a fate choice through differences in the relative timing between the two programs. To test this proposed dynamic mechanism, we altered the relative timing by engineering artificial cross-regulation between the sporulation and competence circuits. Results suggest a simple model that does not require a checkpoint or intricate cross-regulation before cellular decision-making. Rather, cell fate choice appears to be the outcome of a 'molecular race' between differentiation programs that compete in time, providing a simple dynamic mechanism for decision-making