scholarly journals The impact of growth stimulators and retardants on the utilization of reserve lipids by sunflower seedlings

2017 ◽  
Vol 8 (3) ◽  
pp. 317-322 ◽  
Author(s):  
V. G. Kuryata ◽  
І. V. Poprotska ◽  
Т. І. Rogach
Keyword(s):  
Linoleic Acid ◽  
Butyric Acid ◽  
Covalent Bond ◽  
Chemical Compounds ◽  
Lipase Hydrolysis ◽  
The Impact ◽  
Hydrolysis Of ◽  
Higher Fatty Acids

Using growth stimulators and anti-gibberillin preparations of different chemical compounds, we created different pressures in the coordinate covalent bond systems during germination of sunflower seeds. Using gibberellin and treptolem growth stimulators and Paclobutrazol and Chlormequat-Chlorid anti-gibberillin preparations is an efficient method of reconstructing coordinate covalent bond during the germination of seeds of oil-bearing crops. It allows determination of the role of the hormone factor in the utilization of reserve lipids over the heterotrophic phase of plant development. Blocking the synthesis of gibberellins by retardants caused decrease in activity of lipase, hydrolysis of reserve lipids and the meristem, which resulted in decrease in the energy of germination. Compared to the control, the impact of gibberellin increased the content of butyric acid, and the impact of Paclobutrazol reduced the content of butyric acid. Linoleic acid showed exactly the opposite changes. In relation to the control, a significant increase in the content of non-saturated linoleic acid was observed in both variants of the experiment. Gibberellic acid stimulated and Paclobutrazol slowed the usage of free higher fatty acids for the process of morphogenesis. 

scholarly journals Delineating the Polarized and Unpolarized Parton Structure of the Nucleon

2015 ◽  
Vol 37 ◽  
pp. 1560053
Author(s):  
Pedro Jimenez-Delgado
Keyword(s):  
Parton Distribution ◽  
Distribution Functions ◽  
Distribution Analysis ◽  
Coupling Constant ◽  
Parton Distribution Functions ◽  
Careful Treatment ◽  
Future Data ◽  
The Impact

Reports on our latest extractions of parton distribution functions of the nucleon are given. First an overview of the recent JR14 upgrade of our unpolarized PDFs, including NNLO determinations of the strong coupling constant and a discussion of the role of the input scale in parton distribution analysis. In the second part of the talk recent results on the determination of spin-dependent PDFs from the JAM collaboration are reported, including a careful treatment of hadronic and nuclear corrections, as well as reports on the impact of present and future data in our understanding of the spin of the nucleon.

scholarly journals A Control Based Mathematical Model for the Evaluation of Intervention Lines in COVID-19 Epidemic Spread: The Italian Case Study

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 890
Author(s):  
Paolo Di Giamberardino ◽  
Rita Caldarella ◽  
Daniela Iacoviello
Keyword(s):  
Mathematical Model ◽  
Equilibrium Points ◽  
Italian Case ◽  
Control Actions ◽  
Containment Measures ◽  
Asymptomatic Subjects ◽  
The Impact

This paper addresses the problem of describing the spread of COVID-19 by a mathematical model introducing all the possible control actions as prevention (informative campaign, use of masks, social distancing, vaccination) and medication. The model adopted is similar to SEIQR, with the infected patients split into groups of asymptomatic subjects and isolated ones. This distinction is particularly important in the current pandemic, due to the fundamental the role of asymptomatic subjects in the virus diffusion. The influence of the control actions is considered in analysing the model, from the calculus of the equilibrium points to the determination of the reproduction number. This choice is motivated by the fact that the available organised data have been collected since from the end of February 2020, and almost simultaneously containment measures, increasing in typology and effectiveness, have been applied. The characteristics of COVID-19, not fully understood yet, suggest an asymmetric diffusion among countries and among categories of subjects. Referring to the Italian situation, the containment measures, as applied by the population, have been identified, showing their relation with the government's decisions; this allows the study of possible scenarios, comparing the impact of different possible choices.

scholarly journals Kinetics and Mechanism of Hydrolysis of Acetylthiocholine by Butyrylcholine Esterase

2002 ◽  
Vol 57 (11-12) ◽  
pp. 1072-1077 ◽  
Author(s):  
Karel Komers ◽  
Alexandr Čegan ◽  
Marek Link
Keyword(s):  
Acetic Acid ◽  
Kinetics And Mechanism ◽  
Kinetics Parameters ◽  
Mechanism Of Hydrolysis ◽  
Ph Stat ◽  
Stat Method ◽  
Ellman’S Method ◽  
Hydrolysis Of

Kinetics and mechanism of hydrolysis of acetylthiocholine by the enzyme butyrylcholine esterase was studied. The spectrophotometric Ellman’s method and potentiometric pH-stat method were used for continuous determination of the actual concentration of the products thiocholine and acetic acid in the reaction mixture. The validity of the Michaelis-Menten (Briggs-Haldane) equation in the whole course of the reaction under used conditions was proved. The corresponding kinetics parameters (Vm and KM) were calculated from the obtained dependences of concentration of thiocholine or acetic acid vs. time and compared. From this comparison the deciding kinetic role of the step producing thiocholine was derived. The values of initial molar concentration of the enzyme and of the rate constants of the kinetic model were estimated.

Commercial Dental Composite: Determination of Reaction Advancement and Study of the Migration of Organic Compounds

2005 ◽  
Vol 13 (3) ◽  
pp. 223-234
Author(s):  
C. Sanglar ◽  
M. Defay ◽  
H. Waton ◽  
A. Bonhomme ◽  
S. Alamercery ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
Aqueous Media ◽  
Dental Composite ◽  
Dental Composites ◽  
Hydrophilic Monomer ◽  
Methacrylate Monomers ◽  
Urethane Dimethacrylate ◽  
Hydrolysis Of

This work on organic dental composites was undertaken to determine the role of residual reactive methacrylate functions at the end of the photopolymerization cycle, and to investigate the fate of the residual monomers and oligomers in organic (ethanol) and aqueous (water and artificial saliva) media. The results show that all the methacrylate monomers present in dentine migrate into ethanol (about 1% (w/w)). In aqueous media on the other hand, only the most hydrophilic monomer (UDMA) migrates (0.05% (w/w)) into water and 0.03% into artificial saliva (pH = 9). This desorption in the three media is accompanied by the hydrolysis of monomers, leading to the formation of monohydrolyzed urethane dimethacrylate (UDMA) and bis-phenyl glycidyl dimethacrylate (BISGMA); UDMA and BISGMA are completely hydrolyzed in artificial saliva. The alkalinity of the milieu apparently favours the hydrolysis of methacrylate functions.

scholarly journals The Impact of Education, Health, Experience and Government Loans on Farmers’ Productivity in District Nowshera

2018 ◽  
Vol III (I) ◽  
pp. 83-100
Author(s):  
Imran Ullah Saeed ◽  
Muhammad Jehangir ◽  
Muhammad Tariq
Keyword(s):  
Field Survey ◽  
Primary Data ◽  
Maximum Output ◽  
Output Level ◽  
Tomato Production ◽  
Education And Health ◽  
The Impact ◽  
Socio Economic Factors

This study generally examines the influence of education, health, experience and government loans on farmers’ productivity in district Nowshera. Specifically, this study (a) finds out the role of socio-economic factors determining tomato production in district Nowshera and (b) estimates technical efficiency of the tomato farmers in the area. Primary data has been collected through a field survey from 61 tomato producers of selected villages of the district. The results reveal on the average tomato farms in the study area are 95% efficient, indicating a 5% potential for the farms to attain the maximum output level while the range of efficiencies was 89% to 99%. Moreover, the results also showed education, health, experience and government loans playing a significant role in the determination of the tomato production. On the basis of these results, it is suggested that government increase spending on education and health as such loans can play an important role in the tomato farming in district Nowshera.

The role of the main ingredients of chocolate in the formation of its beneficial properties for the consumer

2021 ◽  
pp. 582-587
Author(s):  
I.V. Goloviznin ◽  
A.V. Ryzhakova
Keyword(s):  
Human Health ◽  
Complete Information ◽  
The Body ◽  
Specific Product ◽  
Regular Process ◽  
The World ◽  
The Impact ◽  
Confectionery Product

Chocolate is the most staple and consumed confectionery product in Russia and the world. The determination of the beneficial properties of such a product as chocolate is an important and regular process of food institutions in every country, since new lines of already well-known manufacturers and new manufacturers with an innovative assortment are added to the retail assortment. Today, it is very relevant and important to understand the impact of new products on human health. In this regard, in order to provide complete information on a specific product, it is necessary to know its composition, ingredients and their effect on the body separately and within the framework of a specific product. Along with its beneficial properties, chocolate can also affect health negatively. It is necessary to understand the mechanism of the effect of chocolate on human health when consumed and to assess the risks that may arise subsequently after its active consumption.

The Role of Gender and Gender Dynamics in Same-Sex Divorce and Dissolution

2018 ◽  
pp. 353-382
Author(s):  
Suzanne A. Kim ◽  
Edward Stein
Keyword(s):  
Future Research ◽  
Relationship Dissolution ◽  
Legal Institution ◽  
Same Sex ◽  
Gender Dynamics ◽  
Same Sex Couples ◽  
And Gender ◽  
The Impact

This chapter identifies ways researchers, policymakers, therapists, lawyers, and couples should attend to the role of gender and gender dynamics facing same-sex couples upon divorce or relationship dissolution. When same-sex couples marry, gender roles associated with a particular vision of different-sex couples—in reference to which the legal institution of marriage developed historically—may be projected onto same-sex couples both socially and by judges adjudicating their relationship dissolutions, often in a manner conflicting with couples’ intentions and practices. Thus, couples consisting of two men and couples consisting of two women may be differentially affected. Gender and gender dynamics are likely to affect the bases for dissolution (e.g., whether one of the spouses committed adultery or whether there is a basis for annulment); the financial aspects of dissolution; and determination of child custody. The chapter suggests directions for future research regarding the impact of gender on the dissolution of same-sex relationships.

scholarly journals Mechanochemical coupling in the relaxation of rigor-wave sea urchin sperm flagella.

1982 ◽  
Vol 92 (3) ◽  
pp. 733-741 ◽  
Author(s):  
S M Penningroth ◽  
A Cheung ◽  
K Olehnik ◽  
R Koslosky
Keyword(s):  
Sea Urchin ◽  
Atp Hydrolysis ◽  
Bend Angle ◽  
Flagellar Motility ◽  
Lytechinus Pictus ◽  
Mechanochemical Coupling ◽  
Mechanochemical Cycle ◽  
Hydrolysis Of

The relaxation (straightening) of flagellar rigor waves, which is known to be induced by micromolar ATP concentrations was investigated with respect to its dependence on the binding and hydrolysis of ATP. Flagellar rigor waves were formed by the dilution of demembranated, reactivated sea urchin (Lytechinus pictus) spermatozoa into ATP-free buffer. Relaxation in response to nucleotide was quantitated by measuring theta, the mean flagellar bend angle per sperm; this novel assay permitted determination of the rate of relaxation. It was found that (a) the rate of flagellar relaxation induced by 4 X 10(-6) M ATP was inhibited 80% by vanadate concentrations of 3 X 10(-6) M and above; (b) of 16 hydrolyzable and nonhydrolyzable nucleotide di-, tri-, and tetraphosphates tested, only three, each of which was hydrolyzed by the flagellar axonemal ATPase activity (ATP, dATP, and epsilon-ATP) were also capable of effecting relaxation; (c) several hundred ATP molecules were estimated to be hydrolyzed by each dynein of ATP hydrolysis, which defines the efficiency of ATP utilization, increased 30-fold as the ATP relaxation depends on ATP hydrolysis; (b) because it depends on ATP hydrolysis, flagellar relaxation is an inappropriate model system for investigating the role of ATP binding in the mechanochemical cycle of dynein; and (c) the efficiency of mechanochemical coupling in flagellar motility is an ATP-dependent phenomenon. A general model of relaxation is proposed based on active microtubule sliding.

scholarly journals KPC-2 β-lactamase Enables Carbapenem Antibiotic Resistance Through Fast Deacylation of the Covalent Intermediate

2020 ◽  
pp. jbc.RA120.015050
Author(s):  
Shrenik C Mehta ◽  
Ian M Furey ◽  
Orville A Pemberton ◽  
David M Boragine ◽  
Yu Chen ◽  
...  
Keyword(s):  
Active Site ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
The Common ◽  
Covalent Intermediate ◽  
Hydrolysis Of ◽  
Carbapenem Antibiotic ◽  
Enzyme Intermediate

Serine active-site β-lactamases hydrolyze β-lactam antibiotics through formation of a covalent acyl-enzyme intermediate followed by deacylation via an activated water molecule. Carbapenem antibiotics are poorly hydrolyzed by most β-lactamases due to slow hydrolysis of the acyl-enzyme intermediate. However, the emergence of the KPC-2 carbapenemase has resulted in widespread resistance to these drugs, suggesting it operates more efficiently. Here, we investigated the unusual features of KPC-2 that enable this resistance. We show that KPC-2 has a 20,000-fold increased deacylation rate compared to the common TEM-1 β-lactamase. Further, kinetic analysis of active site alanine mutants indicates that carbapenem hydrolysis is a concerted effort involving multiple residues. Substitution of Asn170 greatly decreases the deacylation rate, but this residue is conserved in both KPC-2 and non-carbapenemase β-lactamases, suggesting it promotes carbapenem hydrolysis only in the context of KPC-2. X-ray structure determination of the N170A enzyme in complex with hydrolyzed imipenem suggests Asn170 may prevent the inactivation of the deacylating water by the 6α-hydroxyethyl substituent of carbapenems. In addition, the Thr235 residue, which interacts with the C3 carboxylate of carbapenems, also contributes strongly to the deacylation reaction. In contrast, mutation of the Arg220 and Thr237 residues decreases the acylation rate and, paradoxically, improves binding affinity for carbapenems. Thus, the role of these residues may be ground state destabilization of the enzyme-substrate complex or, alternatively, to ensure proper alignment of the substrate with key catalytic residues to facilitate acylation. These findings suggest modifications of the carbapenem scaffold to avoid hydrolysis by KPC-2 β-lactamase.

The nuclear magnetic resonance determination of the conformation of saccharides bound in subsite D of lysozyme

1978 ◽  
Vol 56 (6) ◽  
pp. 624-629 ◽  
Author(s):  
Steven L. Patt ◽  
John H. Baldo ◽  
Kim Boekelheide ◽  
Gregg Weisz ◽  
Brian D. Sykes
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Cell Wall ◽  
Magnetic Resonance ◽  
Dihedral Angle ◽  
Muramic Acid ◽  
Coupling Constant ◽  
Hydrolysis Of ◽  
Nuclear Magnetic

The binding of the trisaccharide (2-acetamido-2-deoxy-D-muramic acid)-β(1→4)-(2-aceta-mido-2-deoxy-D-glucosyl)-β(1→4)-(2-acetamido-2-deoxy-D-muramic acid) to subsites B, C, and D in lysozyme has been studied by 1H nuclear magnetic resonance methods. In particular, the coupling constant between H1 and H2 of the reducing saccharide bound in subsite D has been determined. The coupling constant for the bound saccharide indicates that the dihedral angle between C1 and C2 for the reducing saccharide is not significantly changed upon binding to lysozyme. This result is discussed in terms of other evidence for the role of distortion of the saccharide bound in subsite D in the lysozyme-catalyzed hydrolysis of cell wall oligosaccharides.

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