TY  - CONF
AU  - Maksimović, Jelena
AU  - Ivanović-Šašić, Ana
AU  - Maćešić, Stevan
AU  - Čupić, Željko
AU  - Kolar-Anić, Ljiljana
PY  - 2023
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/7431
AB  - The impact of L-tyrosine amino acid on the kinetics of the BL oscillatory reaction was investigated
under closed reactor conditions. The study was focused on examining the sensitivity of the BL
reaction matrix to tyrosine perturbations. A high sensitivity of the BL matrix to very low tyrosine
concentrations was observed.
PB  - Serbian Society of Mechanics
C3  - 9th International Congress of the Serbian Society of Mechanics, Book of Proceedings, July 5-7, 2023, Vrnjačka Banja, Serbia
T1  - L-tyrosine influence on the reaction kinetics of iodatehydrogen peroxide oscillatory reaction
SP  - 457
EP  - 458
UR  - https://hdl.handle.net/21.15107/rcub_cer_7431
ER  - 

@conference{
author = "Maksimović, Jelena and Ivanović-Šašić, Ana and Maćešić, Stevan and Čupić, Željko and Kolar-Anić, Ljiljana",
year = "2023",
abstract = "The impact of L-tyrosine amino acid on the kinetics of the BL oscillatory reaction was investigated
under closed reactor conditions. The study was focused on examining the sensitivity of the BL
reaction matrix to tyrosine perturbations. A high sensitivity of the BL matrix to very low tyrosine
concentrations was observed.",
publisher = "Serbian Society of Mechanics",
journal = "9th International Congress of the Serbian Society of Mechanics, Book of Proceedings, July 5-7, 2023, Vrnjačka Banja, Serbia",
title = "L-tyrosine influence on the reaction kinetics of iodatehydrogen peroxide oscillatory reaction",
pages = "457-458",
url = "https://hdl.handle.net/21.15107/rcub_cer_7431"
}

Maksimović, J., Ivanović-Šašić, A., Maćešić, S., Čupić, Ž.,& Kolar-Anić, L.. (2023). L-tyrosine influence on the reaction kinetics of iodatehydrogen peroxide oscillatory reaction. in 9th International Congress of the Serbian Society of Mechanics, Book of Proceedings, July 5-7, 2023, Vrnjačka Banja, Serbia
Serbian Society of Mechanics., 457-458.
https://hdl.handle.net/21.15107/rcub_cer_7431

Maksimović J, Ivanović-Šašić A, Maćešić S, Čupić Ž, Kolar-Anić L. L-tyrosine influence on the reaction kinetics of iodatehydrogen peroxide oscillatory reaction. in 9th International Congress of the Serbian Society of Mechanics, Book of Proceedings, July 5-7, 2023, Vrnjačka Banja, Serbia. 2023;:457-458.
https://hdl.handle.net/21.15107/rcub_cer_7431 .

Maksimović, Jelena, Ivanović-Šašić, Ana, Maćešić, Stevan, Čupić, Željko, Kolar-Anić, Ljiljana, "L-tyrosine influence on the reaction kinetics of iodatehydrogen peroxide oscillatory reaction" in 9th International Congress of the Serbian Society of Mechanics, Book of Proceedings, July 5-7, 2023, Vrnjačka Banja, Serbia (2023):457-458,
https://hdl.handle.net/21.15107/rcub_cer_7431 .

TY  - CONF
AU  - Ivanović-Šašić, Ana
AU  - Maćešić, Stevan
AU  - Maksimović, Jelena
AU  - Čupić, Željko
AU  - Kolar-Anić, Ljiljana
PY  - 2023
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/7430
AB  - It is well known that almost all living or biological systems are naturally in the oscillatory dynamic states and can be considered as biochemical reaction systems. These oscillatory dynamic states can be caused by internal self-organized phenomena, but also by external periodic variations of temperature, light, food, or seasonal changes. The hypothalamic-pituitary-thyroid (HPT) axis is one such nonlinear system with feedback that is always in an oscillatory dynamic state and L-tyrosine is its main representative.
The biological importance of L-tyrosine interactions with iodine species was the motivation for modelling of the oscillatory dynamics in the Bray-Liebhafsky (BL) reaction perturbed by L- tyrosine. Also, direct experimental investigation of metabolic processes in the human body is extremely complex to be done, and therefore any alternative approach is of great importance. Therefore, the BL reaction has the potential to be used as a model of the biological system due to certain characteristics shared with the considered processes; it is characterized by its oscillatory dynamics and based on the chemistry of hydrogen peroxide and iodine compounds commonly present in the thyroid gland, where L-tyrosine is iodinated.
The impact of L-tyrosine on the dynamics of the Bray-Lienbhafsky oscillatory reaction was investigated numerically using the proposed model. The study was focused on the examination of the sensitivity of the BL reaction to L-tyrosine perturbation. The obtained results indicated possible pathways of influence
PB  - Kragujevac, Serbia : Institute for Information Technologies, University of Kragujevac
C3  - 2nd International Conference on Chemo and Bioinformatics ICCBIKG 2023, Book of proceedings, September 28-29, 2023, Kragujevac, Serbia
T1  - Numerical simulations of the oscillatory dynamics in the Bray-Liebhafsky reaction perturbed by L-tyrosine
VL  - 612
SP  - 609
DO  - 10.46793/ICCBI23.609IS
ER  - 

@conference{
author = "Ivanović-Šašić, Ana and Maćešić, Stevan and Maksimović, Jelena and Čupić, Željko and Kolar-Anić, Ljiljana",
year = "2023",
abstract = "It is well known that almost all living or biological systems are naturally in the oscillatory dynamic states and can be considered as biochemical reaction systems. These oscillatory dynamic states can be caused by internal self-organized phenomena, but also by external periodic variations of temperature, light, food, or seasonal changes. The hypothalamic-pituitary-thyroid (HPT) axis is one such nonlinear system with feedback that is always in an oscillatory dynamic state and L-tyrosine is its main representative.
The biological importance of L-tyrosine interactions with iodine species was the motivation for modelling of the oscillatory dynamics in the Bray-Liebhafsky (BL) reaction perturbed by L- tyrosine. Also, direct experimental investigation of metabolic processes in the human body is extremely complex to be done, and therefore any alternative approach is of great importance. Therefore, the BL reaction has the potential to be used as a model of the biological system due to certain characteristics shared with the considered processes; it is characterized by its oscillatory dynamics and based on the chemistry of hydrogen peroxide and iodine compounds commonly present in the thyroid gland, where L-tyrosine is iodinated.
The impact of L-tyrosine on the dynamics of the Bray-Lienbhafsky oscillatory reaction was investigated numerically using the proposed model. The study was focused on the examination of the sensitivity of the BL reaction to L-tyrosine perturbation. The obtained results indicated possible pathways of influence",
publisher = "Kragujevac, Serbia : Institute for Information Technologies, University of Kragujevac",
journal = "2nd International Conference on Chemo and Bioinformatics ICCBIKG 2023, Book of proceedings, September 28-29, 2023, Kragujevac, Serbia",
title = "Numerical simulations of the oscillatory dynamics in the Bray-Liebhafsky reaction perturbed by L-tyrosine",
volume = "612",
pages = "609",
doi = "10.46793/ICCBI23.609IS"
}

Ivanović-Šašić, A., Maćešić, S., Maksimović, J., Čupić, Ž.,& Kolar-Anić, L.. (2023). Numerical simulations of the oscillatory dynamics in the Bray-Liebhafsky reaction perturbed by L-tyrosine. in 2nd International Conference on Chemo and Bioinformatics ICCBIKG 2023, Book of proceedings, September 28-29, 2023, Kragujevac, Serbia
Kragujevac, Serbia : Institute for Information Technologies, University of Kragujevac., 612, 609.
https://doi.org/10.46793/ICCBI23.609IS

Ivanović-Šašić A, Maćešić S, Maksimović J, Čupić Ž, Kolar-Anić L. Numerical simulations of the oscillatory dynamics in the Bray-Liebhafsky reaction perturbed by L-tyrosine. in 2nd International Conference on Chemo and Bioinformatics ICCBIKG 2023, Book of proceedings, September 28-29, 2023, Kragujevac, Serbia. 2023;612:609.
doi:10.46793/ICCBI23.609IS .

Ivanović-Šašić, Ana, Maćešić, Stevan, Maksimović, Jelena, Čupić, Željko, Kolar-Anić, Ljiljana, "Numerical simulations of the oscillatory dynamics in the Bray-Liebhafsky reaction perturbed by L-tyrosine" in 2nd International Conference on Chemo and Bioinformatics ICCBIKG 2023, Book of proceedings, September 28-29, 2023, Kragujevac, Serbia, 612 (2023):609,
https://doi.org/10.46793/ICCBI23.609IS . .

TY  - CONF
AU  - Čupić, Željko
AU  - Ivanović-Šašić, Ana
PY  - 2023
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/6415
AB  - Nonlinear feedback loops inherent to neuroendocrine systems are among the most important information flows at the organism level. They support high sensitivity and responsiveness of the living beings to external perturbations. Moreover, nonlinear feedback loops enable efficient control over dynamic physiological states. Often, they can be recognized through emergence of various dynamic phenomena, such as biological rhythmicity. Typical examples of such neuroendocrine systems are the hypothalamic-pituitary-adrenal (HPA) axis and the hypothalamic–pituitary–thyroid (HPT) axis. They are characterized by rhythmic dynamics with two characteristic periods, circadian (~ 24 h) and ultradian (20 min – 120 min), which allows living organisms to quickly adjust their neuroendocrine activity to fluctuations in their surroundings and/or their internal physiology.
We focus our research on mechanistic modelling of biochemical transformations that underlay complex neuroendocrine networks. Thus far, we have developed several variants of low-dimensional and extended models for the HPA axis, as well as, one medium scale model of the HPT axis. Both of them are assembled by combinations of the pseudo-reaction steps, describing in essence the information flow through the network of chemical transformations. Their role in physiological system is to maintain basal levels of hormone concentrations, and enable their functionally reasonable change when some need emerges. Our models enable one to emulate in numerical simulations changes in blood level of relevant hormones that constitute the HPA or HPT axis (Jelić et al. 2005, Marković et al. 2011, Čupić et al. 2017, Kolar-Anić et al. 2023).
The high predictive value of our models paves the way for their use in medical diagnostics of neuroendocrine diseases and for more efficient corticosteroid treatment that is applied in various illnesses, by harnessing the power of the underlying nonlinear feedback loops to the dosage of corticosteroid drugs could be significantly decreased, while preserving their efficacy. We pay special attention to the Stoichiometric Network Analysis of reaction network models to identify conditions ensuring the existence of unstable steady states, and in particular, Hopf bifurcation as a most plausible path leading to the oscillatory dynamics. The simplest way to use this template is to replace the text in this file with your own words using the styles provided as far as possible.
PB  - Belgrade : Research and Development institute Lola Ltd
PB  - COST Action CA21169 DYNALIFE
C3  - Book of abstracts - Modelling Information Flow in Biological Coding Systems, COST Action CA21169 DYNALIFE, WG1 Meeting, Jun 20–21, 2023, Belgrade
T1  - Modeling the Non-Linear Dynamics of Information Flows in Neuro-Endocrine Systems
SP  - 9
EP  - 9
UR  - https://hdl.handle.net/21.15107/rcub_cer_6415
ER  - 

@conference{
author = "Čupić, Željko and Ivanović-Šašić, Ana",
year = "2023",
abstract = "Nonlinear feedback loops inherent to neuroendocrine systems are among the most important information flows at the organism level. They support high sensitivity and responsiveness of the living beings to external perturbations. Moreover, nonlinear feedback loops enable efficient control over dynamic physiological states. Often, they can be recognized through emergence of various dynamic phenomena, such as biological rhythmicity. Typical examples of such neuroendocrine systems are the hypothalamic-pituitary-adrenal (HPA) axis and the hypothalamic–pituitary–thyroid (HPT) axis. They are characterized by rhythmic dynamics with two characteristic periods, circadian (~ 24 h) and ultradian (20 min – 120 min), which allows living organisms to quickly adjust their neuroendocrine activity to fluctuations in their surroundings and/or their internal physiology.
We focus our research on mechanistic modelling of biochemical transformations that underlay complex neuroendocrine networks. Thus far, we have developed several variants of low-dimensional and extended models for the HPA axis, as well as, one medium scale model of the HPT axis. Both of them are assembled by combinations of the pseudo-reaction steps, describing in essence the information flow through the network of chemical transformations. Their role in physiological system is to maintain basal levels of hormone concentrations, and enable their functionally reasonable change when some need emerges. Our models enable one to emulate in numerical simulations changes in blood level of relevant hormones that constitute the HPA or HPT axis (Jelić et al. 2005, Marković et al. 2011, Čupić et al. 2017, Kolar-Anić et al. 2023).
The high predictive value of our models paves the way for their use in medical diagnostics of neuroendocrine diseases and for more efficient corticosteroid treatment that is applied in various illnesses, by harnessing the power of the underlying nonlinear feedback loops to the dosage of corticosteroid drugs could be significantly decreased, while preserving their efficacy. We pay special attention to the Stoichiometric Network Analysis of reaction network models to identify conditions ensuring the existence of unstable steady states, and in particular, Hopf bifurcation as a most plausible path leading to the oscillatory dynamics. The simplest way to use this template is to replace the text in this file with your own words using the styles provided as far as possible.",
publisher = "Belgrade : Research and Development institute Lola Ltd, COST Action CA21169 DYNALIFE",
journal = "Book of abstracts - Modelling Information Flow in Biological Coding Systems, COST Action CA21169 DYNALIFE, WG1 Meeting, Jun 20–21, 2023, Belgrade",
title = "Modeling the Non-Linear Dynamics of Information Flows in Neuro-Endocrine Systems",
pages = "9-9",
url = "https://hdl.handle.net/21.15107/rcub_cer_6415"
}

Čupić, Ž.,& Ivanović-Šašić, A.. (2023). Modeling the Non-Linear Dynamics of Information Flows in Neuro-Endocrine Systems. in Book of abstracts - Modelling Information Flow in Biological Coding Systems, COST Action CA21169 DYNALIFE, WG1 Meeting, Jun 20–21, 2023, Belgrade
Belgrade : Research and Development institute Lola Ltd., 9-9.
https://hdl.handle.net/21.15107/rcub_cer_6415

Čupić Ž, Ivanović-Šašić A. Modeling the Non-Linear Dynamics of Information Flows in Neuro-Endocrine Systems. in Book of abstracts - Modelling Information Flow in Biological Coding Systems, COST Action CA21169 DYNALIFE, WG1 Meeting, Jun 20–21, 2023, Belgrade. 2023;:9-9.
https://hdl.handle.net/21.15107/rcub_cer_6415 .

Čupić, Željko, Ivanović-Šašić, Ana, "Modeling the Non-Linear Dynamics of Information Flows in Neuro-Endocrine Systems" in Book of abstracts - Modelling Information Flow in Biological Coding Systems, COST Action CA21169 DYNALIFE, WG1 Meeting, Jun 20–21, 2023, Belgrade (2023):9-9,
https://hdl.handle.net/21.15107/rcub_cer_6415 .

TY  - JOUR
AU  - Kolar-Anić, Ljiljana
AU  - Čupić, Željko
AU  - Maćešić, Stevan
AU  - Ivanović-Šašić, Ana
AU  - Dietrich, Johannes
PY  - 2023
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/6416
AB  - The synthesis of thyroid hormones in the hypothalamic-pituitary-thyroid (HPT) axis was studied. For this purpose,
a reaction model for HPT axis with stoichiometric relations between the main reaction species was
postulated. Using the law of mass action, this model has been transformed into a set of nonlinear ordinary
differential equations. This new model has been examined by stoichiometric network analysis (SNA) with the aim
to see if it possesses the ability to reproduce oscillatory ultradian dynamics founded on the internal feedback
mechanism. In particular, a feedback regulation of TSH production based on the interplay between TRH, TSH,
somatostatin and thyroid hormones was proposed. Besides, the ten times larger amount of produced T4 with
respect to T3 in the thyroid gland was successfully simulated. The properties of SNA in combination with
experimental results, were used to determine the unknown parameters (19 rate constants of particular reaction
steps) necessary for numerical investigations. The steady-state concentrations of 15 reactive species were tuned
to be consistent with the experimental data. The predictive potential of the proposed model was illustrated on
numerical simulations of somatostatin influence on TSH dynamics investigated experimentally by Weeke et al. in
1975. In addition, all programs for SNA analysis were adapted for this kind of a large model. The procedure of
calculating rate constants from steady-state reaction rates and very limited available experimental data was
developed. For this purpose, a unique numerical method was developed to fine-tune model parameters while
preserving the fixed rate ratios and using the magnitude of the experimentally known oscillation period as the
only target value. The postulated model was numerically validated by perturbation simulations with somatostatin
infusion and the results were compared with experiments available in literature. Finally, as far as we know,
this reaction model with 15 variables is the most dimensional one that have been analysed mathematically to
obtain instability region and oscillatory dynamic states. Among the existing models of thyroid homeostasis this
theory represents a new class that may improve our understanding of basic physiological processes and helps to
develop new therapeutic approaches. Additionally, it may pave the way to improved diagnostic methods for
pituitary and thyroid disorders.
PB  - Elsevier
T2  - Computers in Biology and Medicine
T1  - Modelling of the thyroid hormone synthesis as a part of nonlinear reaction mechanism with feedback
VL  - 160
SP  - 106980
DO  - 10.1016/j.compbiomed.2023.106980
ER  - 

@article{
author = "Kolar-Anić, Ljiljana and Čupić, Željko and Maćešić, Stevan and Ivanović-Šašić, Ana and Dietrich, Johannes",
year = "2023",
abstract = "The synthesis of thyroid hormones in the hypothalamic-pituitary-thyroid (HPT) axis was studied. For this purpose,
a reaction model for HPT axis with stoichiometric relations between the main reaction species was
postulated. Using the law of mass action, this model has been transformed into a set of nonlinear ordinary
differential equations. This new model has been examined by stoichiometric network analysis (SNA) with the aim
to see if it possesses the ability to reproduce oscillatory ultradian dynamics founded on the internal feedback
mechanism. In particular, a feedback regulation of TSH production based on the interplay between TRH, TSH,
somatostatin and thyroid hormones was proposed. Besides, the ten times larger amount of produced T4 with
respect to T3 in the thyroid gland was successfully simulated. The properties of SNA in combination with
experimental results, were used to determine the unknown parameters (19 rate constants of particular reaction
steps) necessary for numerical investigations. The steady-state concentrations of 15 reactive species were tuned
to be consistent with the experimental data. The predictive potential of the proposed model was illustrated on
numerical simulations of somatostatin influence on TSH dynamics investigated experimentally by Weeke et al. in
1975. In addition, all programs for SNA analysis were adapted for this kind of a large model. The procedure of
calculating rate constants from steady-state reaction rates and very limited available experimental data was
developed. For this purpose, a unique numerical method was developed to fine-tune model parameters while
preserving the fixed rate ratios and using the magnitude of the experimentally known oscillation period as the
only target value. The postulated model was numerically validated by perturbation simulations with somatostatin
infusion and the results were compared with experiments available in literature. Finally, as far as we know,
this reaction model with 15 variables is the most dimensional one that have been analysed mathematically to
obtain instability region and oscillatory dynamic states. Among the existing models of thyroid homeostasis this
theory represents a new class that may improve our understanding of basic physiological processes and helps to
develop new therapeutic approaches. Additionally, it may pave the way to improved diagnostic methods for
pituitary and thyroid disorders.",
publisher = "Elsevier",
journal = "Computers in Biology and Medicine",
title = "Modelling of the thyroid hormone synthesis as a part of nonlinear reaction mechanism with feedback",
volume = "160",
pages = "106980",
doi = "10.1016/j.compbiomed.2023.106980"
}

Kolar-Anić, L., Čupić, Ž., Maćešić, S., Ivanović-Šašić, A.,& Dietrich, J.. (2023). Modelling of the thyroid hormone synthesis as a part of nonlinear reaction mechanism with feedback. in Computers in Biology and Medicine
Elsevier., 160, 106980.
https://doi.org/10.1016/j.compbiomed.2023.106980

Kolar-Anić L, Čupić Ž, Maćešić S, Ivanović-Šašić A, Dietrich J. Modelling of the thyroid hormone synthesis as a part of nonlinear reaction mechanism with feedback. in Computers in Biology and Medicine. 2023;160:106980.
doi:10.1016/j.compbiomed.2023.106980 .

Kolar-Anić, Ljiljana, Čupić, Željko, Maćešić, Stevan, Ivanović-Šašić, Ana, Dietrich, Johannes, "Modelling of the thyroid hormone synthesis as a part of nonlinear reaction mechanism with feedback" in Computers in Biology and Medicine, 160 (2023):106980,
https://doi.org/10.1016/j.compbiomed.2023.106980 . .

TY  - JOUR
AU  - Maćešić, Stevan
AU  - Čupić, Željko
AU  - Kolar-Anić, Ljiljana
PY  - 2023
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/7185
AB  - The effect of diffusion on the steady-state stability of an oscillatory chemical reaction model was investigated using stoichiometric network analysis and numerical simulations. Under both spatially uniform and nonuniform conditions, steady-state stability was investigated. Under spatially uniform conditions, the model can simulate oscillatory dynamics by passing through the Andronov-Hopf bifurcation. When diffusion is introduced into the system, the results have shown that two scenarios through which instabilities can occur are possible. Either, oscillations may be caused by the same instability as it was in homogeneous case, or, diffusion may cause new type of instability. Using the exponent polytope method, we derived a system of inequalities that describes the conditions for the emergence of both, oscillations, and diffusion-driven instabilities.
PB  - Elsevier
T2  - Chaos, Solitons & Fractals
T1  - Effect of diffusion on steady state stability of an oscillatory reaction model
VL  - 174
SP  - 113783
DO  - 10.1016/j.chaos.2023.113783
ER  - 

@article{
author = "Maćešić, Stevan and Čupić, Željko and Kolar-Anić, Ljiljana",
year = "2023",
abstract = "The effect of diffusion on the steady-state stability of an oscillatory chemical reaction model was investigated using stoichiometric network analysis and numerical simulations. Under both spatially uniform and nonuniform conditions, steady-state stability was investigated. Under spatially uniform conditions, the model can simulate oscillatory dynamics by passing through the Andronov-Hopf bifurcation. When diffusion is introduced into the system, the results have shown that two scenarios through which instabilities can occur are possible. Either, oscillations may be caused by the same instability as it was in homogeneous case, or, diffusion may cause new type of instability. Using the exponent polytope method, we derived a system of inequalities that describes the conditions for the emergence of both, oscillations, and diffusion-driven instabilities.",
publisher = "Elsevier",
journal = "Chaos, Solitons & Fractals",
title = "Effect of diffusion on steady state stability of an oscillatory reaction model",
volume = "174",
pages = "113783",
doi = "10.1016/j.chaos.2023.113783"
}

Maćešić, S., Čupić, Ž.,& Kolar-Anić, L.. (2023). Effect of diffusion on steady state stability of an oscillatory reaction model. in Chaos, Solitons & Fractals
Elsevier., 174, 113783.
https://doi.org/10.1016/j.chaos.2023.113783

Maćešić S, Čupić Ž, Kolar-Anić L. Effect of diffusion on steady state stability of an oscillatory reaction model. in Chaos, Solitons & Fractals. 2023;174:113783.
doi:10.1016/j.chaos.2023.113783 .

Maćešić, Stevan, Čupić, Željko, Kolar-Anić, Ljiljana, "Effect of diffusion on steady state stability of an oscillatory reaction model" in Chaos, Solitons & Fractals, 174 (2023):113783,
https://doi.org/10.1016/j.chaos.2023.113783 . .

TY  - CONF
AU  - Čupić, Željko
AU  - Ivanović-Šašić, Ana
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/6414
AB  - Many physicochemical processes can exhibit various forms of non-linear
dynamics, which have been widely investigated in the oscillatory
reaction Bray-Liebhafsky, too. The stoichiometry of this reaction
corresponds to the hydrogen peroxide decomposition to water and
oxygen in an acidic environment, in the presence of iodate ions as a
catalyst. During this reaction an oscillatory change of the intermediate
species concentration, along with a cascade change in the hydrogen
peroxide concentration and oxygen removal can be obtained. By
selecting the experimental conditions, the simple periodic or complex
chaotic concentration changes can be generated. Concentration
oscillations are a consequence of alternating dominance of different
reaction pathways present in the reaction mechanism. Large extent of the
phenomena experimentally observed in the oscillatory reaction Bray-
Liebhafsky is well explained by the mechanistic model, investigated by
the Belgrade group over a many years.
PB  - Serbian Academy of Nonlinear Sciences
C3  - Proceedings - 2nd Conference on Nonlinearity, October 18 – 22, 2021, Belgrade, Serbia
T1  - Bray-Liebhafsky reaction: From monotonous to chaotic evolution
SP  - 170
EP  - 199
UR  - https://hdl.handle.net/21.15107/rcub_cer_6414
ER  - 

@conference{
author = "Čupić, Željko and Ivanović-Šašić, Ana",
year = "2022",
abstract = "Many physicochemical processes can exhibit various forms of non-linear
dynamics, which have been widely investigated in the oscillatory
reaction Bray-Liebhafsky, too. The stoichiometry of this reaction
corresponds to the hydrogen peroxide decomposition to water and
oxygen in an acidic environment, in the presence of iodate ions as a
catalyst. During this reaction an oscillatory change of the intermediate
species concentration, along with a cascade change in the hydrogen
peroxide concentration and oxygen removal can be obtained. By
selecting the experimental conditions, the simple periodic or complex
chaotic concentration changes can be generated. Concentration
oscillations are a consequence of alternating dominance of different
reaction pathways present in the reaction mechanism. Large extent of the
phenomena experimentally observed in the oscillatory reaction Bray-
Liebhafsky is well explained by the mechanistic model, investigated by
the Belgrade group over a many years.",
publisher = "Serbian Academy of Nonlinear Sciences",
journal = "Proceedings - 2nd Conference on Nonlinearity, October 18 – 22, 2021, Belgrade, Serbia",
title = "Bray-Liebhafsky reaction: From monotonous to chaotic evolution",
pages = "170-199",
url = "https://hdl.handle.net/21.15107/rcub_cer_6414"
}

Čupić, Ž.,& Ivanović-Šašić, A.. (2022). Bray-Liebhafsky reaction: From monotonous to chaotic evolution. in Proceedings - 2nd Conference on Nonlinearity, October 18 – 22, 2021, Belgrade, Serbia
Serbian Academy of Nonlinear Sciences., 170-199.
https://hdl.handle.net/21.15107/rcub_cer_6414

Čupić Ž, Ivanović-Šašić A. Bray-Liebhafsky reaction: From monotonous to chaotic evolution. in Proceedings - 2nd Conference on Nonlinearity, October 18 – 22, 2021, Belgrade, Serbia. 2022;:170-199.
https://hdl.handle.net/21.15107/rcub_cer_6414 .

Čupić, Željko, Ivanović-Šašić, Ana, "Bray-Liebhafsky reaction: From monotonous to chaotic evolution" in Proceedings - 2nd Conference on Nonlinearity, October 18 – 22, 2021, Belgrade, Serbia (2022):170-199,
https://hdl.handle.net/21.15107/rcub_cer_6414 .

TY  - JOUR
AU  - Negrojević, Luka
AU  - Lončar, Aleksandar
AU  - Maksimović, Jelena
AU  - Anić, Slobodan
AU  - Čupić, Željko
AU  - Kolar-Anić, Ljiljana
AU  - Pejić, Nataša
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5253
AB  - A kinetic method for the determination of l-tyrosine (Tyr) by analyte pulse perturbation, caused by different amounts of Tyr, in the Bray–Liebhafsky (BL) oscillatory reaction realized in a continuous-flow stirred tank reactor, is proposed. For such purposes, the BL oscillating reaction was kept in a stable non-equilibrium stationary state close to the bifurcation point and was used as the matrix reaction system. Under optimum reaction conditions, the linear relationship between the kinetic parameters, Δτ2 (the period between first two oscillations that appear after applied perturbation) as well as τend (the time elapsed between the perturbation of the BL reaction by Tyr and the termination of the oscillatory phase) and the Tyr concentrations is obtained over the ranges 1.1 × 10− 6 − 9.2 × 10− 6 mol L− 1 and 1.1 × 10− 6 − 1.4 × 10− 5 mol L− 1, with the limit of detections of 6.6 × 10− 7 mol L− 1 and 6.4 × 10− 7 mol L− 1. The described method that relies on a simple instrumental set-up, has been successfully applied to the determination of Tyr in a dietary supplement. Some aspects of the possible mechanism of Tyr action on the BL oscillator are discussed.
PB  - Springer
T2  - Reaction Kinetics, Mechanisms and Catalysis
T1  - Bray–Liebhafsky oscillatory reaction in a continuous-flow stirred tank reactor as the matrix system for determination of tyrosine
VL  - 135
SP  - 1147
EP  - 1162
DO  - 10.1007/s11144-021-02130-5
ER  - 

@article{
author = "Negrojević, Luka and Lončar, Aleksandar and Maksimović, Jelena and Anić, Slobodan and Čupić, Željko and Kolar-Anić, Ljiljana and Pejić, Nataša",
year = "2022",
abstract = "A kinetic method for the determination of l-tyrosine (Tyr) by analyte pulse perturbation, caused by different amounts of Tyr, in the Bray–Liebhafsky (BL) oscillatory reaction realized in a continuous-flow stirred tank reactor, is proposed. For such purposes, the BL oscillating reaction was kept in a stable non-equilibrium stationary state close to the bifurcation point and was used as the matrix reaction system. Under optimum reaction conditions, the linear relationship between the kinetic parameters, Δτ2 (the period between first two oscillations that appear after applied perturbation) as well as τend (the time elapsed between the perturbation of the BL reaction by Tyr and the termination of the oscillatory phase) and the Tyr concentrations is obtained over the ranges 1.1 × 10− 6 − 9.2 × 10− 6 mol L− 1 and 1.1 × 10− 6 − 1.4 × 10− 5 mol L− 1, with the limit of detections of 6.6 × 10− 7 mol L− 1 and 6.4 × 10− 7 mol L− 1. The described method that relies on a simple instrumental set-up, has been successfully applied to the determination of Tyr in a dietary supplement. Some aspects of the possible mechanism of Tyr action on the BL oscillator are discussed.",
publisher = "Springer",
journal = "Reaction Kinetics, Mechanisms and Catalysis",
title = "Bray–Liebhafsky oscillatory reaction in a continuous-flow stirred tank reactor as the matrix system for determination of tyrosine",
volume = "135",
pages = "1147-1162",
doi = "10.1007/s11144-021-02130-5"
}

Negrojević, L., Lončar, A., Maksimović, J., Anić, S., Čupić, Ž., Kolar-Anić, L.,& Pejić, N.. (2022). Bray–Liebhafsky oscillatory reaction in a continuous-flow stirred tank reactor as the matrix system for determination of tyrosine. in Reaction Kinetics, Mechanisms and Catalysis
Springer., 135, 1147-1162.
https://doi.org/10.1007/s11144-021-02130-5

Negrojević L, Lončar A, Maksimović J, Anić S, Čupić Ž, Kolar-Anić L, Pejić N. Bray–Liebhafsky oscillatory reaction in a continuous-flow stirred tank reactor as the matrix system for determination of tyrosine. in Reaction Kinetics, Mechanisms and Catalysis. 2022;135:1147-1162.
doi:10.1007/s11144-021-02130-5 .

Negrojević, Luka, Lončar, Aleksandar, Maksimović, Jelena, Anić, Slobodan, Čupić, Željko, Kolar-Anić, Ljiljana, Pejić, Nataša, "Bray–Liebhafsky oscillatory reaction in a continuous-flow stirred tank reactor as the matrix system for determination of tyrosine" in Reaction Kinetics, Mechanisms and Catalysis, 135 (2022):1147-1162,
https://doi.org/10.1007/s11144-021-02130-5 . .

TY  - JOUR
AU  - Stojiljković, Aleksandra S.
AU  - Čupić, Željko
AU  - Maćešić, Stevan
AU  - Ivanović - Šašić, Ana
AU  - Kolar-Anić, Ljiljana
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5390
AB  - Numerous studies on humans and animals have indicated that the corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP) stimulate both individually and synergistically secretion of adrenocorticotropic hormone (ACTH) by corticotropic cells in anterior pituitary. With aim to characterize and better comprehend the mechanisms underlying the effects of AVP on Hypothalamic-Pituitary-Adrenal (HPA) axis ultradian dynamics, AVP is here incorporated into our previously proposed stoichiometric model of HPA axis in humans. This extended nonlinear network reaction model took into account AVP by: reaction steps associated with two separate inflows of AVP into pituitary portal system, that is synthesized and released from hypothalamic parvocellular and magnocellular neuronal populations, as well as summarized reaction steps related to its individual and synergistic action with CRH on corticotropic cells. To explore the properties of extended model and its capacity to emulate the effects of AVP, nonlinear dynamical systems theory and bifurcation analyses based on numerical simulations were utilized to determine the dependence of ultradian oscillations on rate constants of the inflows of CRH and AVP from parvocellular neuronal populations, the conditions under which dynamical transitions occur due to their synergistic action and, moreover, the types of these transitions. The results show that under certain conditions, HPA system could enter into oscillatory dynamic states from stable steady state and vice versa under the influence of synergy reaction rate constant. Transitions between these dynamical states were always through supercritical Andronov-Hopf bifurcation point. Also, results revealed the conditions under which amplitudes of ultradian oscillations could increase several-fold due to CRH and AVP synergistic stimulation of ACTH secretion in accordance with results reported in the literature. Moreover, results showed experimentally observed superiority of CRH as a stimulator of ACTH secretion compared to AVP in humans. The proposed model can be very useful in studies related to the role of AVP and its synergistic action with CRH in life-threatening circumstances such as acute homeostasis dynamic crisis, autoimmune inflammations or severe hypovolemia requiring instant or several-days sustained corticosteroid excess levels. Moreover, the model can be helpful for investigations of indirect AVP-induced HPA activity by exogenously administered AVP used in therapeutic treatment.
PB  - Frontiers Media S.A.
T2  - Frontiers in Endokrinology
T1  - Influence of arginine vasopressin on the ultradian dynamics of Hypothalamic-Pituitary-Adrenal axis
VL  - 13
SP  - 976323
DO  - 10.3389/fendo.2022.976323
ER  - 

@article{
author = "Stojiljković, Aleksandra S. and Čupić, Željko and Maćešić, Stevan and Ivanović - Šašić, Ana and Kolar-Anić, Ljiljana",
year = "2022",
abstract = "Numerous studies on humans and animals have indicated that the corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP) stimulate both individually and synergistically secretion of adrenocorticotropic hormone (ACTH) by corticotropic cells in anterior pituitary. With aim to characterize and better comprehend the mechanisms underlying the effects of AVP on Hypothalamic-Pituitary-Adrenal (HPA) axis ultradian dynamics, AVP is here incorporated into our previously proposed stoichiometric model of HPA axis in humans. This extended nonlinear network reaction model took into account AVP by: reaction steps associated with two separate inflows of AVP into pituitary portal system, that is synthesized and released from hypothalamic parvocellular and magnocellular neuronal populations, as well as summarized reaction steps related to its individual and synergistic action with CRH on corticotropic cells. To explore the properties of extended model and its capacity to emulate the effects of AVP, nonlinear dynamical systems theory and bifurcation analyses based on numerical simulations were utilized to determine the dependence of ultradian oscillations on rate constants of the inflows of CRH and AVP from parvocellular neuronal populations, the conditions under which dynamical transitions occur due to their synergistic action and, moreover, the types of these transitions. The results show that under certain conditions, HPA system could enter into oscillatory dynamic states from stable steady state and vice versa under the influence of synergy reaction rate constant. Transitions between these dynamical states were always through supercritical Andronov-Hopf bifurcation point. Also, results revealed the conditions under which amplitudes of ultradian oscillations could increase several-fold due to CRH and AVP synergistic stimulation of ACTH secretion in accordance with results reported in the literature. Moreover, results showed experimentally observed superiority of CRH as a stimulator of ACTH secretion compared to AVP in humans. The proposed model can be very useful in studies related to the role of AVP and its synergistic action with CRH in life-threatening circumstances such as acute homeostasis dynamic crisis, autoimmune inflammations or severe hypovolemia requiring instant or several-days sustained corticosteroid excess levels. Moreover, the model can be helpful for investigations of indirect AVP-induced HPA activity by exogenously administered AVP used in therapeutic treatment.",
publisher = "Frontiers Media S.A.",
journal = "Frontiers in Endokrinology",
title = "Influence of arginine vasopressin on the ultradian dynamics of Hypothalamic-Pituitary-Adrenal axis",
volume = "13",
pages = "976323",
doi = "10.3389/fendo.2022.976323"
}

Stojiljković, A. S., Čupić, Ž., Maćešić, S., Ivanović - Šašić, A.,& Kolar-Anić, L.. (2022). Influence of arginine vasopressin on the ultradian dynamics of Hypothalamic-Pituitary-Adrenal axis. in Frontiers in Endokrinology
Frontiers Media S.A.., 13, 976323.
https://doi.org/10.3389/fendo.2022.976323

Stojiljković AS, Čupić Ž, Maćešić S, Ivanović - Šašić A, Kolar-Anić L. Influence of arginine vasopressin on the ultradian dynamics of Hypothalamic-Pituitary-Adrenal axis. in Frontiers in Endokrinology. 2022;13:976323.
doi:10.3389/fendo.2022.976323 .

Stojiljković, Aleksandra S., Čupić, Željko, Maćešić, Stevan, Ivanović - Šašić, Ana, Kolar-Anić, Ljiljana, "Influence of arginine vasopressin on the ultradian dynamics of Hypothalamic-Pituitary-Adrenal axis" in Frontiers in Endokrinology, 13 (2022):976323,
https://doi.org/10.3389/fendo.2022.976323 . .

TY  - BOOK
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5114
AB  - Apstrakti sa uvodnog sastanka NES projekta.
PB  - Beograd : Univerzitet u Beogradu, Institut za hemiju, tehnologiju i metalurgiju, Institut od nacionalnog značaja
T1  - Fizičkohemijski aspekti ritmičnosti NeuroEndokrinih Sistema : Dinamička i kinetička istraživanja reakcionih mreža i glavnih jedinjenja koja leže u njihovoj osnovi (NES) - Uvodni sastanak, knjiga apstrakata
UR  - https://hdl.handle.net/21.15107/rcub_cer_5114
ER  - 

@book{
year = "2022",
abstract = "Apstrakti sa uvodnog sastanka NES projekta.",
publisher = "Beograd : Univerzitet u Beogradu, Institut za hemiju, tehnologiju i metalurgiju, Institut od nacionalnog značaja",
title = "Fizičkohemijski aspekti ritmičnosti NeuroEndokrinih Sistema : Dinamička i kinetička istraživanja reakcionih mreža i glavnih jedinjenja koja leže u njihovoj osnovi (NES) - Uvodni sastanak, knjiga apstrakata",
url = "https://hdl.handle.net/21.15107/rcub_cer_5114"
}

(2022). Fizičkohemijski aspekti ritmičnosti NeuroEndokrinih Sistema : Dinamička i kinetička istraživanja reakcionih mreža i glavnih jedinjenja koja leže u njihovoj osnovi (NES) - Uvodni sastanak, knjiga apstrakata. 
Beograd : Univerzitet u Beogradu, Institut za hemiju, tehnologiju i metalurgiju, Institut od nacionalnog značaja..
https://hdl.handle.net/21.15107/rcub_cer_5114

Fizičkohemijski aspekti ritmičnosti NeuroEndokrinih Sistema : Dinamička i kinetička istraživanja reakcionih mreža i glavnih jedinjenja koja leže u njihovoj osnovi (NES) - Uvodni sastanak, knjiga apstrakata. 2022;.
https://hdl.handle.net/21.15107/rcub_cer_5114 .

"Fizičkohemijski aspekti ritmičnosti NeuroEndokrinih Sistema : Dinamička i kinetička istraživanja reakcionih mreža i glavnih jedinjenja koja leže u njihovoj osnovi (NES) - Uvodni sastanak, knjiga apstrakata" (2022),
https://hdl.handle.net/21.15107/rcub_cer_5114 .